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# CERN Published Articles

2018-11-16
06:28
 Status of the LHC and possible scenarios for the luminosity upgrade / Scandale, W (CERN) 2006 - 16 p. - Published in : Italian Phys. Soc. Proc.: 92 (2006) , pp. 3-18 In : 3rd Italian Workshop on ATLAS and CMS Physics, Bari, Italy, 20 - 22 Oct 2005, pp.3-18

2018-11-16
06:28
 Calibration of the ATLAS and CMS calormetric detectors / Carminati, L (Milan U. ; INFN, Milan) ; Govoni, P (INFN, Milan) The present status of the ATLAS and CMS calorimeters is reviewed. After a brief description of the calorimetric systems we present the e/gamma, jets and missing energy reconstruction capabilities of the ATLAS and CMS detectors. [...] 2006 - 8 p. - Published in : Italian Phys. Soc. Proc.: 92 (2006) , pp. 21-28 In : 3rd Italian Workshop on ATLAS and CMS Physics, Bari, Italy, 20 - 22 Oct 2005, pp.21-28

2018-11-16
06:28
 Alignment, status of the activity and impact on ATLAS and CMS first data / Cerminara, G (INFN, Turin ; Turin U.) ; Della Pietra, M (INFN, Naples ; Naples U.) The ability to accurately align the tracking devices will be essential to fully exploit the ATLAS and CMS design performance. The general alignment strategy of the two detectors is presented, focusing, in particular, on commonalities and differences between the two procedures. [...] 2006 - 10 p. - Published in : Italian Phys. Soc. Proc.: 92 (2006) , pp. 29-38 In : 3rd Italian Workshop on ATLAS and CMS Physics, Bari, Italy, 20 - 22 Oct 2005, pp.29-38

2018-11-16
06:28
 Computing in running experiments: The experience of CDF, D0 and BABAR / Fabozzi, F (INFN, Naples) ; Lucchesi, D (INFN, Padua) Experiments at the LHC will face an unprecedented amount of data, which has to be efficiently recorded, reconstructed, and analysed by a world-wide collaboration. The experience of the currently running experiments CDF and D0 at Fermilab and BABAR at SLAC can be very precious in order to find proper solutions to the challenging computing issues expected at the LHC. [...] 2006 - 8 p. - Published in : Italian Phys. Soc. Proc.: 92 (2006) , pp. 41-48 In : 3rd Italian Workshop on ATLAS and CMS Physics, Bari, Italy, 20 - 22 Oct 2005, pp.41-48

2018-11-16
06:28
 Software and analysis model plans for commissioning and data taking / Ambroglini, F (Perugia U.) ; Resconi, S (INFN, Milan) ATLAS and CMS are preparing their offline software and analysis model for the following goals: processing of the events delivered by the trigger and data acquisition system, delivering the processed results to physicists , providing tools for them to analyse the processed information in order to produce physics results. The difference design principles and strategies of ATLAS and CMS are discussed.. 2006 - 7 p. - Published in : Italian Phys. Soc. Proc.: 92 (2006) , pp. 59-65 In : 3rd Italian Workshop on ATLAS and CMS Physics, Bari, Italy, 20 - 22 Oct 2005, pp.59-65

2018-11-16
06:28
 Physics background at Tevatron / Messina, A (INFN, Rome2) In this contribution I will characterize the physics background to high PT signals at the Tevatron collider.. 2006 - 7 p. - Published in : Italian Phys. Soc. Proc.: 92 (2006) , pp. 69-75 In : 3rd Italian Workshop on ATLAS and CMS Physics, Bari, Italy, 20 - 22 Oct 2005, pp.69-75

2018-11-16
06:28
 Physics background at LHC / Ranieri, R (INFN, Florence ; Florence U.) A lot of physics channels occurring with very low cross sections will be studied at LHC, their signals will be overwhelmed by different backgrounds. The extraction of rare signals has to be supported by the precise study of the backgrounds involved. [...] 2006 - 7 p. - Published in : Italian Phys. Soc. Proc.: 92 (2006) , pp. 77-83 In : 3rd Italian Workshop on ATLAS and CMS Physics, Bari, Italy, 20 - 22 Oct 2005, pp.77-83

2018-11-16
06:28
 Top physics at the LHC dawn / Benucci, L (INFN, Pisa) ; Dotti, A (INFN, Pisa) 2006 - 11 p. - Published in : Italian Phys. Soc. Proc.: 92 (2006) , pp. 97-107 In : 3rd Italian Workshop on ATLAS and CMS Physics, Bari, Italy, 20 - 22 Oct 2005, pp.97-107

2018-11-16
06:28
 Search for Supersymmetry with early LHC data / Galanti, M (INFN, Catania ; Catania U.) ; Lari, T (INFN, Milan) The potential of the ATLAS and CMS experiments to discover and study the signals expected from the production of Supersymmetric particles with the first few fb - 1 of data delivered by the LHC is illustrated.. 2006 - 8 p. - Published in : Italian Phys. Soc. Proc.: 92 (2006) , pp. 111-118 In : 3rd Italian Workshop on ATLAS and CMS Physics, Bari, Italy, 20 - 22 Oct 2005, pp.111-118

2018-11-16
06:28
 Perspectives for early non-SUSY discoveries of physics beyond the Standard Model at LHC / Franzoni, F (Minnesota U.) ; Menici, L (Rome U. ; INFN, Rome) Approaching the start-up of the Large Hadron Collider project, it is interesting to understand which possible processes could provide some evidence of physics Beyond the Standard model (BSM) with the first 1-100 fb${^-1}$ of integrated luminosity. Here we will not consider models based on Supersymmetry (SUSY); rather, between the plethora of non-SUSY models of physics BSM, we are going to go over two very promising classes of phenomenologies: Extra Gauge Bosons and Extra Dimensions.. 2006 - 9 p. - Published in : Italian Phys. Soc. Proc.: 92 (2006) , pp. 119-127 In : 3rd Italian Workshop on ATLAS and CMS Physics, Bari, Italy, 20 - 22 Oct 2005, pp.119-127


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Token Economics
Financial Model
Deployment
Usecases (soon)
Glossary

# zMorgan

Expand the cryptocurrency market with real-world financial assets and copy trillions of capital into the new decentralized economy.

zMorgan is an on-chain platform for Securities-Backed crypto Lending.

# What Is a Securities-Backed Loan?

A securities-backed loan is a loan backed by publicly traded securities such as stocks or bonds as collateral. A borrower deposits securities into an escrow account on which the lender has a lien, and the lender will usually make available loan funds in the amount from 50% to 95% of the securities’ market value. An available credit limit depends on the specific securities in the portfolio and the level of diversification. For example, if a lender might approve more funding against a portfolio of U.S. Treasury notes than a portfolio that holds a single, concentrated stock position.

## When do clients consider taking a securities-based loan?

Usually there are three general purposes for taking a securities-based loan:

1. Return enhancement: clients take a loan backed by a securities portfolio and re-invest the loan to increase the portfolio’s expected returns (and risk).

2. Diversification: clients take a loan backed by a concentrated portfolio (e.g. small number of securities) and use the loan to invest in a diversified portfolio, thereby increasing the overall diversification of the investment portfolio.

3. Liquidity: clients take a loan backed by a securities portfolio and use the loan externally.

## Key Advantages of Securities-Based Lending

A securities-based line of credit helps borrowers to meet their liquidity cash needs by unlocking the value of their investments without selling them.

Some of the advantages of securities-based lending include:

• Access to cash when a borrower needs it, potentially avoiding capital gains taxes from selling securities

• Typically lower rates than other forms of credit. The first ingredient in the cost of a securities-based loan is a central bank policy rate within a certain country. With central banks keeping rates lower for longer, this looks set to remain low for the foreseeable future in most developed economies. Meanwhile, since securities-based loans are backed by portfolios, the spread over policy rates can be relatively low. As the first consideration in making a loan is the difference between the estimated interest rate on the loan versus the expected return of the investment, securities-based lending has become increasingly attractive.

For example, UBS Group AG’s case study shows how an investor with a portfolio valued at EUR 10 million, who wants to buy an apartment worth EUR 3 million, would forgo a EUR 1.1 million return over 10 years by selling parts of their portfolio instead of using a securities-based loan.

• Flexibility in borrowing: there are no restrictions on what the loan can be used for

• Not included on monthly credit reporting and not affect a Borrower's credit score

• Less paperwork compared to traditional loans

The benefits of marketable securities backed finance include:

• Liquidity to pursue your existing investment strategy and investment opportunities

• Additional capital without selling securities

• No interruption to your asset allocation and long-term investment strategy

• Freedom to alter the strategy or focus of your portfolio being used as collateral

• Credit lines/loans structured according to your individual needs with regards to type, amount, tenor, repayment and currency (including cryptocurrency)

• Portfolio yield enhancement

## Risks in Securities-Based Lending

The risks inherent in securities-based lending are not always readily apparent, but must be recognized as an important consideration when operating a securities-based loan.

### Leverage effect

If a securities-based loan is taken out for investment purposes (crypto investment or other), the investment risk will increase since there is no guarantee of how much return the investment will actually yield. Depending on the market situation, it is possible that the interest on a securities-based loan will be higher than the returns. In this case, a borrower would generate a negative leverage effect.

Using a well-diversified portfolio as collateral and investing the loan proceeds into a well-diversified solution reduces financial market risk. Investors should typically not make use of the maximum lending value available. Dynamic asset allocation strategies with risk-mitigating features can further reduce portfolio volatility and alleviate the risk of financial losses due to a collateral shortfall event. Choosing a loan tenor that is in line with the investor’s interest rate expectations and risk profile helps to keep funding cost risks under control. Borrowing against a securities portfolio with little or positive correlation to interest rate increases also lowers risk.

So, leverage provides the opportunity of realizing higher portfolio returns, but also entails higher risks. While risks can never be eliminated, they can be mitigated. The likelihood of return enhancement is higher with longer investment horizons and better-diversified portfolios.

### Minimum cover requirements

If the value of your securities falls below a certain limit, you may be asked by Zamzam to furnish additional collateral (margin call) or to repay the loan in part or in full. If you are unable to meet this obligation to make an additional capital contribution or repay the loan, Zamzam may liquidate some or all of the investments used to secure the loan.

However, within zMorgan we offer to borrow about 50% of the value of securities that allows us to maintain a conservative cushion to reduce the threat of liquidation.

### Liquidity bottlenecks

Insufficient funds to cover interest installments due or redemption of the loan may result in the sale of the pledged securities at an inopportune point in time.

### Accrued Benefits

Zamzam as a lender must be able to accurately determine which benefits he is due, and a borrower must be able to remit them on the due date. Zamzam must also ensure that if a loan was returned prior to the payable date, the benefit due is secured.

### Tax implications

An additional benefit in certain jurisdictions is the tax deductibility of loan interest payments. The ability to deduct the tax on loan interest payments lowers the “effective” funding cost for the loan.

For example, private individuals who have unlimited tax liability in Switzerland usually are able to exclude the debt and the cost of interest from their taxable assets or income. However, if loans were issued for finance security transactions purposes the Swiss Tax Authorities determine a taxpayer as a professional securities dealer. In this case, capital gains would be taxed as income.

# Mechanisms

## Smart contract

All terms of loans on zMorgan are controlled by smart contracts. A smart contract is a coded contract or transaction protocol that automatically executes, controls, and enforces the terms and conditions and provides a transparent, fair arbitration process.

## Oracles

Oracles allow our blockchain and smart contracts to interact with external data. They search, verify, and authenticate external data and then transmit it to smart contracts. They act as an API to external data sources providing accurate data from external sources.

## Escrow Account

Securities portfolio is put into the care of a third party (escrow agent) and such portfolio is held in an escrow account for delivery only when certain specified conditions are met - the loan is fully paid by the borrower.

# How it works

Our goal is to allow the lenders to transfer investment coins to the borrower, and the borrower distribute repayments to all lenders, while achieving unlinkability. Without a loss of generality, we assume there are a certain number of lenders and one borrower. We separate the protocol into negotiation phase, lending phase and returning phase. The detailed lending and borrowing process is summarized in the Figure below.

## Negotiation

First, within Zamzam platform a borrower verifies his identity and then submits his loan application attaching necessary documents in respect of a securities portfolio information. The borrower and Zamzam agree on the following loan information: total amount of a loan, numbers of repayment (loan term), interest rate.

Second, the borrower deposits the securities portfolio to Zamzam platform and this securities portfolio is transferred to a broker’s escrow account.

The borrower pays zMorgan Protocol fees that cover the broker’s commission for the escrow account and transaction fees. Zamzam tokenizes the securities portfolio and the information about the tokenized securities portfolio is posted to the dashboard.

Third, Zamzam creates a 2-of-2 multisig escrow account with the borrower. Based on the interest rate and loan terms, a repayment plan must be set upfront. After the lending platform gets a repayment from the borrower, the platform distributes the repayment to the lenders based on their lending amount. We introduce a variable repayment list agreed upon by both the borrower and Zamzam, then committed and posted to the dashboard. All loan information is posted to the dashboard for a lender’s review.

Each repayment varies in a certain range (number of repayments), but the total repayment amount is still equal to the desired repayment. Since Zamzam can not predict the total number of lenders, we can not construct the repayment plan in advance based just on the agreement between the borrower and Zamzam. Each individual borrowed amount must be divided by the number of lenders.

## Lending and Borrowing

After a lender compares the borrower's project information and interest rate on the dashboard, we assume the lender wants to lend a certain amount of coins to the borrower through Zamzam platform. The lender asks Zamzam to set up a payment channel. Then the lender deposits USDT, BUSD or USDC in the desired investing amount on the blockchain via 2-of-2 escrow transaction with Zamzam. Upon the funded coins exceeding the proposed in a certain ratio Zamzam collects funded coins. In case some lenders change their mind before the deadline of fundraising and drop off this loan opportunity Zamzam is capable of collecting over-fundraising in a certain ratio.

After the borrower’s loan request is successfully funded, Zamzam generates the final repayment plan that is posted on the dashboard and transfers certain amount of $ZAMs to the lenders as incentives. Then Zamzam sets up a mutually signed escrow and transfers to the borrower the desirable loan amount in$USDZ.

## Repayment

According to the final repayment plan the borrower pays the interests and loan principal in $USDZ through Zamzam platform. Zamzam creates a transaction to each eligible lender to pay them according to their lending amount and the repayment amount. Zamzam also implements the conversion of the repaid loan amount from$USDZ (from the borrower) to USDT, BUSD or USDC (to the lenders).

After Zamzam confirms the loan is fully paid by the borrower, the borrower receives back his secured portfolio used as collateral.

The information about the paid loan is posted on the dashboard.

## Collateral

Both processes of lending and borrowing require risk management. Therefore, a liquidation and risk management protocol can make sure that all loans are properly backed.

Collateral is based on LTV ratio. LTV stands for Loan to Value and represents the ratio between loan amount and deposited collateral:

$LTV = Loan/Collateral$

ZMorgan enforces a minimum 50% LTV ratio, meaning you'll need to deposit no less than 2X the amount you're borrowing as collateral (a maximum collateral coverage ratio is 200%).

The collateral coverage ratio is counted as collateral value divided by the total loan amount.

# Reporting

Data on total value locked in pool, value of escrowed stocks and transactions with their wallet addresses are reported and accessible via zMetaBoard.

format: plain


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# In ConfigTransport.java , what is the use of signature?

In the ConfigTransport.java, I noticed functions like SetPasscode or getVersion for example uses a signature="XX", what is the use of this? Where is this checked against? Do we need to specify a signature for any new method we write for the device?

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the signature="xx" (it should be lower case xx not capital.) In the annotation tells AllJoyn the input type for the method, signal or property. Since I don't know the location of the ConfigTransport.java I don't know what the code there looks like. it most likely looks something similar to this.

@BusMethod(signature="xx")
public void someMethod(long a, long b);

The signature comes from AllJoyns type signatures. For a full list of the signatures see the documentation. Most of the time in Java you don't need to specify the signature unless it critical for communication with a different language. Even then its not typically needed. In the example above AllJoyn would have used interspection to see that the input parameters were both type long with is the same as int64 or 'x'. The code should work just as well with out explicitly listing the signature. This is not always true. Example you are providing an unsigned integer. Java does not provide unsigned data types. While unsigned data types are common in other programming languages.

@BusMethod(signature="uu")
public void someMethod(int a, long b);

In the above example both a and b would be sent across the wire as a unsigned 32-bit integer uint32. The difference is that a uint32 ranges from 0-232 while the range of java int is -231 to 231-1. Since only the positive numbers are used that gives a range of 0 to 231-1. If you need to full range of uint32 you must have a value in java that can hold the entire 0-232 value a long can be used instead of an int.

The only time you will likely need to manually specify a signature is if you are talking to a program written in another language. Where it will be critical that both programming languages agree on what data is sent across the wire.

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Database connection leak in Typo 4.0.3: problem solved

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In an earlier post I wrote about stability problems that have plagued my blog since upgrading from Typo 4.0.0 to 4.0.3. I have finally traced the problem to its source, and here’s the deal:

If you’re serving Typo up via Mongrel, do not configure ActiveRecord to allow concurrency.

One of the changes between Typo 4.0.0 and 4.0.3 is this addition to the environment.rb file:

config.active_record.allow_concurrency = true

Comment out this line, restart Typo, and the problem is solved. Apply Changeset 1255, and the problem is solved. (See Update 2, below.)

Discussion

When ActiveRecord::Base.allow_concurrency is set to true, AR will give each thread its own database connections and cache them in thread-localized storage. The idea is that, in a multi-threaded environment, this simple policy prevents unsafe interactions between threads and the database. (Imagine what would happen if one thread “borrowed” a connection over which another thread had opened a transaction. Oops, there goes transactional isolation.)

This policy, however, does place a burden on the owner of the threads to make sure that each thread’s local connection cache is cleared when the thread is joined, a burden that is not, it would seem, being carried by Typo under Mongrel. As a result, Typo rapidly chews through the allotment of file descriptors that the operating system kindly had reserved for Mongrel:

(On my Linux server, the Mongrel process gets an allotment of 1024 file descriptors.)

Lucky for us, this each-thread-gets-its-own-connections policy is unnecessary under Mongrel because Mongrel, while being multi-threaded itself, serializes all access to the Rails-based applications it serves up:

Q: Is [Mongrel] multi-threaded or can it handle concurrent requests?

Mongrel is uses a pool of thread workers to do it’s processing. This means that it is able to handle concurrent access and should be thread safe. This also means that you have to be more careful about how you use Mongrel. You can’t just write your application assuming that there are no threads involved. …

Ruby on Rails is not thread safe so there is a synchronized block around the calls to Dispatcher.dispatch. This means that everything is threaded right before and right after Rails runs. While Rails is running there is only one controller in operation at a time.

(Source: Mongrel FAQ list)

Thus we can safely turn off (i.e., comment out in Typo’s environment.rb file) ActiveRecord’s allow-currency option without having to worry about nasty concurrency or performance issues:

# the following line is commented out
# config.active_record.allow_concurrency = true

For more on this subject, see Rails ticket #2162 and Rails ticket #2742.

Now, here’s my question: Are there any environments in which Typo can run with the allow-concurrency option enabled and not leak database connections? Inquiring minds want to know.

Update: Upon further investigation, turning off concurrency might not be altogether without risk. Some of the Typo code that handles potentially long tasks, such as making trackbacks and pings, spawns new threads in which to carry out its work. I’m looking further into this risk. Updates to come.

Update 2: Piers Cawley added Changeset 1255, which turns AR’s allow-concurrency flag back off and revises the ping code so that it does not attempt concurrent database access. Apply the patch version of 1255 and restart Typo to get the fix. A tip of the hat to Piers for making the quick fix when he was supposed to be on holiday.


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# Evaluate the limit, if it exist. lim_{x to 0} {sin (pi - x)} / {square root {x^2 - x + 1}}.

## Question:

Evaluate the limit, if it exist.

{eq}\displaystyle \lim_{x \to 0} \dfrac {\sin (\pi - x)} {\sqrt {x^2 - x + 1}} {/eq}.

## The Limit in Calculus:

If the limit of a function {eq}f(x) {/eq} can be writen as: {eq}\displaystyle\lim_{x\rightarrow \, a} f(x) {/eq}. The limit of a function is used to analyze the behavior of a function near the input point.

To solve this problem, we'll apply direct substitution, which is process of directly substitute the given value of {eq}x {/eq} and use the trigonometric value {eq}\sin (\pi )= 0 {/eq} and simplify the answer.

## Answer and Explanation:

We are given:

{eq}\displaystyle \lim_{x \to 0} \dfrac {\sin (\pi - x)} {\sqrt {x^2 - x + 1}} {/eq}

Plug in the value of {eq}x=0 {/eq}

{eq}=\dis...

See full answer below.

Become a www.heiqigong.com member to unlock this answer! Create your account


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location:  Publications → journals → CMB
Abstract view

On Strongly Convex Indicatrices in Minkowski Geometry

 MSC Classifications: 46B20 - Geometry and structure of normed linear spaces 53C21 - Methods of Riemannian geometry, including PDE methods; curvature restrictions [See also 58J60] 53A55 - Differential invariants (local theory), geometric objects 52A20 - Convex sets in $n$ dimensions (including convex hypersurfaces) [See also 53A07, 53C45] 53B40 - Finsler spaces and generalizations (areal metrics) 53A35 - Non-Euclidean differential geometry


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Blog of Andrés Aravena
CMB2:

# Homework for class 8

24 March 2016

The library seqinr is needed in all the following exercises.

# Finding all ORFs in bacteria

Prepare a RMarkdown document with the following parts:

1. Write a function named find.codons() with 3 inputs: a genome (a vector of char), a strand (a char, either “+” or “-”) and a frame number (either 0, 1 or 2). The function should return a vector with all codons in that reading frame. You can use the function splitseq(). Verify that all codons have length 3.
2. Apply this function on the genome of E.coli for strands “+” and “-” and for frame 0, 1 and 2. Store the six results on a list named codons with 6 elements.
3. Write a function that, given a list of codons, finds the position of all start codons. You can use the function which. Apply this function to any of the elements of the list codons and store the result in a vector named start.
4. Write a similar function to find the position of the stop codons. Store them in a vector named stop.
5. (Optional) Write a function that, given the vectors start and stop, returns a vector of the lengths of all ORFs. Notice that there may be more than one start codon for each stop codon. Which one is the real start?

# Combine a FASTA file and a GFF file to get the CDS sequences

Write a RMarkdown document that combines the following steps

1. Read the genome of the bacteria from a FASTA file. For example you can use NC_000913.fna. Store the first element of the result in a vector named genome.

2. Read the description of the features from a GFF file and store them in a data frame named features.

3. Write a function that takes the features data frame and returns a new data frame with one row for each CDS and three columns: start, stop and strand. Store the result in a variable named CDS.

4. Write a function that takes a number n, a data frame CDS and a vector genome and returns the nucleotidic sequence of the gene described in the line n of the data frame CDS.

5. Write a function that combines the CDS data frame and the genome vector to produce a list with the nucleotidic sequences of all genes. Each gene sequence is a vector of char.

You can use lapply on the function from the previous question. Store the result in a variable named CDS.sequences.

6. Write a function that takes the CDS.sequences list and produces a list with the aminoacidic sequences of all proteins coded genes. Store the result in protein.sequences.

You can assume that the genetic code is the bacterial one.

7. Write the values of CDS.sequences into a FASTA file. See the function write.fasta().

8. Write another FASTA file with the aminoacidic sequence of the coded proteins. See the translate() function.

The names of the genes in the FASTA output files can be a serial number. See the paste() function if you want to do something nicer.

## Finding Binding Sites

1. Write a function score.position() to evaluate the score of a position for a given position weight matrix. These matrices have 4 rows and 5 to 30 columns. Rows have names corresponding to nucleotides.

The function should work with any position weight matrix. For testing you can download the matrix here. You can read it with

PWM <- read.delim("PWM.txt", header=FALSE, row.names=1)

Inputs:

• pos: position in the genome
• genome: vector of chars
• mat: a position specific score matrix

Output: the score

2. Evaluate it on each position of E.coli genome.


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Abstract

We report the variance effective population size (Ne) in darkblotched rockfish (Sebastes crameri) utilizing the temporal method for overlapping generations, which requires a combination of age-specific demography and genetic information from cohorts. Following calculations of age-specific survival and reproductive success from fishery data, we genotyped a sample (n = 1087) comprised by 6 cohorts (from 1995 to 2000) across 7 microsatellite loci. Our Ne estimate ($N^e$) plus 95% confidence interval was $N^e$ = 9157 [6495–12 215], showing that the breeding population number could be 3–4 orders of magnitude smaller than the census population size ($N^e$ = 24 376 210). Our estimates resemble closely those found for fishes with similar life history, suggesting that the small $N^e/N^$ ratio for S. crameri is most likely explained by a combination of high variance in reproductive success among individuals, genetic structure, and demographic perturbations such as historical fishing. Because small $N^e/N^$ ratios have been commonly associated with potential loss of genetic variation, our estimates need careful consideration in rockfish management and conservation.

Although effective population size (Ne) is a central tenet in theoretical evolutionary biology, empirical estimates of Ne have been difficult to obtain directly from natural populations because key demographic parameters are not available throughout the entire life span of individuals (Waples 2002). The so-called temporal method overcomes this limitation by indirectly assessing the variance Ne from changes in allele frequencies between discrete generations (Waples 1989). Given that Ne represents the breeding population number and determines the intensity of genetic drift in a population (Hedrick 2000), genetic estimates have become crucial information in evaluating conservation risks of natural populations (Frankham 1995). For example, loss of genetic variation, inbreeding depression, and/or greater extinction threat have been commonly associated with small Ne (Lande 1988) and small Ne/N ratios (N = census population size) (Mace and Lande 1991).

One methodological refinement of the temporal method in conservation genetics has been the combination of demographic and genetic information when generations overlap. Essentially, Ne is estimated between adjacent year classes (cohorts) and corrected for overlapping generations using age-specific survivorship and reproductive success estimates (Jorde and Ryman 1995). This approach is suitable for ecologically and economically important long-lived marine species with multiple reproductive events (iteroparity). In addition, a long generation time complicates temporal sampling of allele frequencies among discrete generations, unless historically archived samples spanning several decades are analyzed (e.g., Hauser et al. 2002).

Here we combine age-specific demography and microsatellite DNA data from cohorts of the long-lived marine darkblotched rockfish (Sebastes crameri) to estimate variance effective population size. Darkblotched rockfish is one deep-water representative of the speciose genus Sebastes in the northeastern Pacific. Sebastes crameri is characterized by long life span (maximum age recorded 105 years; Love et al. 2002) and late maturity (males: 5 years, females: 8 years; Nichol and Pikitch 1994). Low levels of biomass motivated the Pacific Fishery Management Council to declare darkblotched rockfish overfished (Rogers et al. 2000). Our goal was to provide estimates of Ne and N and interpret their relevance to rebuilding plans (Rogers 2003) and conservation initiatives for the recovery of heavily exploited rockfish (Berkeley, Hixon, et al. 2004).

Materials and Methods

Samples

Rockfish fin clips (n = 1206) came from an earlier study that analyzed the genetic structure of S. crameri ranging from the coast of Washington to northern California during 2001 and 2002 (Gomez-Uchida and Banks 2005). Ages of sampled fish were determined from otoliths using the break-and-burn technique (Chilton and Beamish 1982).

Molecular Analyses

Freshly extracted DNA from each individual was screened for 7 polymorphic microsatellite loci using polymerase chain reaction (PCR) as presented in Gomez-Uchida and Banks (2005). Extra amplification cycles (e.g., 5–10 cycles) and an additive containing 20 mg/ml of bovine serum albumin were necessary when PCR fragments were weak. Details on the electrophoresis procedures and sizing of PCR fragments can be found in Gomez-Uchida and Banks (2005).

Genetic Data Analyses

Multilocus genotypes were apportioned into cohorts that matched calendar years. In order to provide a global estimate of Ne (e.g., Turner et al. 2002), we pooled genotypes across sampling locations within year classes. Only genetic information from the 6 largest cohorts (1995–2000) (n = 1087) was used during the rest of the analyses. These year classes were homogeneously distributed across the geographic area (Gomez-Uchida D and Banks MA, unpublished data), suggesting no confounding effects of geographic and intercohort differentiation.

Allele frequencies and general statistics (e.g., allelic richness, and expected vs. observed heterozygosity per locus) for each cohort were estimated using GENETIX version 3.3 (Belkhir et al. 2002). The null hypotheses of 1) Hardy–Weinberg equilibrium (HWE) within cohorts and 2) gametic (linkage) equilibrium among loci within cohorts were tested through exact tests implemented in GENEPOP version 3.3 (Raymond and Rousset 1995). The probability of the joint hypothesis over multiple loci was calculated through Fisher's method implemented in GENEPOP. Departures from HWE were further investigated with MICROCHECKER (van Oosterhout et al. 2004) to exclude potential genotyping errors. Finally, selective neutrality of alleles was tested through the X2-statistic between adjacent year classes of Lewontin and Krakauer (1973) (Jorde and Ryman 1996).

Demographic Analyses and Estimation of Ne and N

Age-specific survival rates (li) were estimated from annual survival (Si) calculated for 38 age classes found in stock assessments of S. crameri (Rogers et al. 2000; Rogers 2003). We used the expression

(1)
where Ni,y is the number of individuals at age class i in the year y. In our case, Si corresponds to the arithmetic mean obtained from m = 40 years (1964–2003) of fishery data (Rogers et al. 2000; Rogers 2003) to account for annual variation in mortality rates. Assuming that the survival rate of the first (newborn) age class, l1 = 1.0 (Jorde and Ryman 1996), then li+1 = Sili.

To obtain age-specific reproductive success (pi), we used the mean number of progeny per male (bim) and female (bif) for each particular age class as “proxy” estimators. These are the proportions of sexually mature rockfish at age from Nichol and Pikitch (1994) times the mean weight at age from (Rogers et al. 2000; Rogers 2003). These variables were adjusted to result in a net reproduction rate for each sex. Finally, we derived a value of reproductive success weighing both sexes equally: (Jorde and Ryman 1996).

An estimate of Ne ($N^e$) was obtained using the temporal method for overlapping generations as described in Jorde and Ryman (1995). Briefly, we used the equation:

(2)
where C is a correction factor obtained from li and pi, G is the mean generation length, and $F¯′$ is the grand mean of temporal allele frequency change (among all adjacent cohorts and over all loci) derived from Pollak (1983) and corrected for sampling variance. Equations to compute $F¯′$C, and G are found in Jorde and Ryman (1995). In addition, the 95% confidence interval (CI) for $F¯′$and $N^e$ was calculated according to Waples (1989) assuming a chi-square distribution for F.

The estimated census population size ($N^$) corresponded to the arithmetic mean of total numbers of fish in the population between 2001 and 2002 (Rogers et al. 2000; Rogers 2003).

Results and Discussion

Cohort genetic statistics did not vary significantly among cohorts; in addition, no significant deviations from HWE were found and linkage equilibrium was met in all pairwise loci comparisons within each year class (Table 1). MICROCHECKER did not detect genotyping errors or null alleles. Lastly, the X2-statistic of Lewontin and Krakauer (1973) suggests that changes in microsatellite allele frequencies between cohorts are the sole effect of genetic drift (Table 2).

Table 1

Cohort genetic statistics for Sebastes crameri

 Cohort 1995 1996 1997 1998 1999 2000 Sample size 48 82 123 67 627 140 HE 0.69 0.7 0.69 0.7 0.71 0.71 HO 0.69 0.68 0.68 0.7 0.71 0.7 AR 8.57 8.39 8.89 8.31 8.99 8.89 HWE 0.36 0.08 0.1 0.46 0.68 0.11
 Cohort 1995 1996 1997 1998 1999 2000 Sample size 48 82 123 67 627 140 HE 0.69 0.7 0.69 0.7 0.71 0.71 HO 0.69 0.68 0.68 0.7 0.71 0.7 AR 8.57 8.39 8.89 8.31 8.99 8.89 HWE 0.36 0.08 0.1 0.46 0.68 0.11

HE, expected heterozygosity; HO, observed heterozygosity; AR, allelic richness; and HWE, exact test for deviations from HWE.

Table 2

Probability values against the null hypothesis of selective neutrality (Lewontin and Krakauer 1973) and the estimator of allele frequency change corrected for sampling error (F′) calculated between adjacent cohorts of Sebastes crameri. $F¯′$ is the arithmetic mean over all cohort pairs

 Cohort pair 1995–1996 1996–1997 1997–1998 1998–1999 1999–2000 Mean ($F¯′$) P(X2) 0.64 0.14 0.52 0.35 0.30 F′ 0.0032 −0.0001 0.0014 −0.0017 0.0005 0.0006
 Cohort pair 1995–1996 1996–1997 1997–1998 1998–1999 1999–2000 Mean ($F¯′$) P(X2) 0.64 0.14 0.52 0.35 0.30 F′ 0.0032 −0.0001 0.0014 −0.0017 0.0005 0.0006

We observed a nearly exponential decline in survival (li) as a function of age; on the contrary, reproductive success (pi) peaked at 8–12 years (Figure 1). Both age-specific variables behaved according to theoretical expectations (e.g., Jorde and Ryman 1995). With these results, we then calculated the following values: C = 110.89 and G = 9.7. An estimate of $F¯′$[95% CI] = 0.0006 [0.0005–0.0009] was obtained by averaging F′ values across cohort pairs shown in Table 2. This provides an overall point estimate plus 95% CI of $N^e$ = 9157 [6495–12 215]. Based on $N^$= 24 376 500, the ratio $N^e/N^$ could therefore vary between 0.001 and 0.0001 for darkblotched rockfish.

Figure 1

Survival rates (li) (empty squares) and rates of reproductive success (pi) (filled triangles) as a function of age in Sebastes crameri.

Figure 1

Survival rates (li) (empty squares) and rates of reproductive success (pi) (filled triangles) as a function of age in Sebastes crameri.

Wright (1931) predicted that under ideal conditions—even sex ratio, nonoverlapping generations, constant population size, panmixia, and Poisson variance in reproductive success among individuals—the ratio Ne/N should approach unity. However, $N^e/N^$ in natural populations average 0.1 using a variety of analytical methods (Frankham 1995), clearly indicating that these ideal conditions are commonly violated in real populations. What biological phenomena can explain the strikingly large discrepancy we observe between $N^e$ and $N^$ values in darkblotched rockfish?

First, uneven sex ratios cannot greatly explain the small ratio $N^e/N^$ found in S. crameri because extensive life-history data suggest no significant departures from 1:1 sex ratios (Nichol and Pikitch 1994; Rogers et al. 2000; Rogers 2003). Second, overlapping generations certainly violate ideal conditions. However, we have employed an ad hoc approach, with stable age structure and constant population size being the basic assumptions of the model. Ages are assumed to be errorless in the theoretical model; however, Rogers (2005) provides evidence that aging errors are commonplace in stock assessments of S. crameri, particularly for older individuals (>20 years old). Imprecise ages are nevertheless more likely to impact the accuracy of N than $N^e$ because 1) we used fish ranging from ages 1 to 7 to obtain the genetic information and 2) the correction factor (C) and mean generation length (G) depend primarily on survival and reproductive success, with both variables decaying rapidly for fish older than 12 years old (Figure 1).

Historical fishing has been demonstrated to truncate age structure and to diminish the population number of numerous groundfish stocks, including our species (Berkeley, Hixon, et al. 2004). From Jorde and Ryman (1996), it is clear that a reduction in age classes will decrease C and $N^e$will therefore be underestimated; they further argue that monitoring the population over time can circumvent demographic disturbances affecting the correction factor C. Long-term genetic data collections during the current stage of stock recovery are thus necessary to validate C and $N^e$ in darkblotched rockfish.

Third, both significant spatial structure and genetic isolation by distance suggest that darkblotched rockfish is not best explained by a panmictic model (Gomez-Uchida and Banks 2005). In principle, a metapopulation with stepping-stone migration can be considered a large single panmictic population for purposes of estimating effective size if the overall genetic differentiation is small (Wang and Caballero 1999) as found in Gomez-Uchida and Banks (2005) for S. crameri. Although differences in size among subpopulations might potentially bias our $N^e$ downwardly (Wang and Caballero 1999), it is unlikely that this alone could account for the large difference in magnitude observed between $N^e$ and $N^$

Fourth, our estimates seem to agree closely with published $N^e$ and $N^e/N^$ ratios for marine fishes with similar life history, including red drum (Turner et al. 2002), New Zealand snapper (Hauser et al. 2002), and Atlantic cod (Hutchinson et al. 2003). These fishes possess both high fecundity and mortality during early life stages (type III survivorship); this life strategy, when coupled with highly variable oceanographic conditions, could lead to a larger variance in reproductive success among individuals (Vk) than expected under a Poisson distribution, with the small minority of individuals ($N^e$) replacing the entire population ($N^$) in every generation (Hedgecock 1994). Recent findings in black rockfish (Sebastes melanops) indicate that older females produce larvae of better quality than younger ones, hence more capable of producing competent offspring (Berkeley, Chapman, and Sogard 2004), supporting the hypothesis that Vk could vary greatly among individual female rockfish.

In conclusion, small $N^e/N^$ for S. crameri is most likely explained by a combination of factors, such as high variance in reproductive success among individuals (Vk), genetic differences among subpopulations, and potential demographic disturbances such as intense fishing. Our results suggest that only several thousand darkblotched rockfish rather than millions in the whole population represent the breeding population number every generation. Given that small ratios $N^e/N^$ are often found within populations of threatened species (Mace and Lande 1991), our estimates need careful consideration for management of vulnerable long-lived stocks (Musick 1999). However, further research is needed to 1) disentangle the individual effects of the aforementioned factors on Ne and 2) obtain independent estimates of key demographic parameters (e.g., Waples 2002) to validate $N^e/N^$ ratios across marine species. Only then will we have confidence in extending findings made here for S. crameri to assess long-term conservation risks of further harvest of other rockfish and marine stocks.

We thank J. B. Rogers at the Northwest Fisheries Science Center in Newport for her comprehensive assessments to understand the population dynamics of darkblotched rockfish and for sharing invaluable demographic information. We are indebted to L. Hauser, P. E. Jorde, R. S. Waples, D.E. Ruzzante, L.W. Seeb, and 3 anonymous referees for providing criticisms on several earlier versions of this paper. Funding for this investigation came from the Cooperative Institute of Marine Resources Studies. The primary author is grateful for a research assistantship from the Coastal Oregon Marine Experiment Station and a Mamie Markham Award from Hatfield Marine Science Center.

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Author notes

Corresponding Editor: Lisa Seeb


text:
## Positive or Negative Acceleration? and Antiderivative of 1/(sin^2)?

I have two quick questions. The first is, if a ball is thrown from a bridge 25 meter above the ground at 49m/s, is the acceleration negative? I thought since it was thrown up, it would be positive, but the book has a similar problem, a ball is thrown upward at a speed of 48ft/s from a cliff 432ft above the ground, and it says the acceleration is -32.

Second, what is the antiderivative of $$\frac{x^2}{\sqrt{x}} + \frac{1}{sin^2x}$$
I can got:
$$\frac{2}{5}x^{5/2}+\frac{1}{\tan{x}}+c$$

But I am pretty sure $$\frac{1}{\tan{x}}$$ isn't right.
 PhysOrg.com science news on PhysOrg.com >> Galaxies fed by funnels of fuel>> The better to see you with: Scientists build record-setting metamaterial flat lens>> Google eyes emerging markets networks
 Recognitions: Gold Member Homework Help Science Advisor As for the acceleration question: Ask yourself: 1. WHAT FORCES ACT UPON THE BALL ONCE IT HAS LEFT YOUR HAND? What is that force's direction? (Assuming there is only one force acting on the ball) 2. How is a force related to acceleration? As for the derivative: You're right, $$\frac{d}{dx}\frac{1}{tan(x)}=-\frac{1}{\sin^{2}x}$$ , not $$\frac{1}{\sin^{2}x}$$
 Gravity will always pull it down, no matter if it was thrown up or down, so acceleration is always negative (assumming it's on Earth, under normal conditions)? The antiderivative is: $$\frac{2}{5}x^{5/2}-\frac{1}{\tan{x}}+c$$ The only thing wrong was the sign?

Recognitions:
Gold Member
Homework Help

## Positive or Negative Acceleration? and Antiderivative of 1/(sin^2)?

Yes, right on both problems.
Note that you will most often find the multiplicative inverse of the tangens function called cotangens:
$$cot(x)\equiv\frac{1}{tan(x)}$$
 I just thought of something else. $$If \csc{x} = \frac{1}{\sin{x}} , then \csc^{2}x = \frac{1}{\sin^{2}x}$$ The antiderivative of $$\csc^{2}{x}$$ is $$-\cot{x}+c$$ Making the final answer be: $$\frac{2}{5}x^{5/2}-\cot{x}+c$$ and not $$\frac{2}{5}x^{5/2}-\frac{1}{\tan{x}}+c$$
 Recognitions: Gold Member Homework Help Science Advisor As I wrote, cotangens IS the multiplicative inverse of tangens. Both answers are equally valid.

Recognitions:
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text:
# Lagrangian (field theory)

LagrangianLagrangian densityLagrangian field theoryLagrangian densitiesLagrangian density functionfield theory LagrangianLagrangian formalismLagrangian formulationLagrangiansmatter Lagrangian
Lagrangian field theory is a formalism in classical field theory.wikipedia
267 Related Articles

### Lagrangian mechanics

LagrangianLagrange's equationsLagrangians
It is the field-theoretic analogue of Lagrangian mechanics.
Lagrangian mechanics applies to the dynamics of particles, while fields are described using a Lagrangian density.

### Classical field theory

field equationsclassical field theoriesfield theory
Lagrangian field theory is a formalism in classical field theory.
A field theory tends to be expressed mathematically by using Lagrangians.

### Scalar curvature

Ricci scalarcurvaturecurvature scalar
:R is the curvature scalar, which is the Ricci tensor contracted with the metric tensor, and the Ricci tensor is the Riemann tensor contracted with a Kronecker delta.
In general relativity, the scalar curvature is the Lagrangian density for the Einstein–Hilbert action.

### Action (physics)

actionaction principleaction integral
The dependent variables (q) are replaced by the value of a field at that point in spacetime so that the equations of motion are obtained by means of an action principle, written as:

### On shell and off shell

on-shelloff-shellon shell
Given boundary conditions, basically a specification of the value of \varphi at the boundary if M is compact or some limit on \varphi as x → ∞ (this will help in doing integration by parts), the subspace of \mathcal{C} consisting of functions, \varphi, such that all functional derivatives of S at \varphi are zero and \varphi satisfies the given boundary conditions is the subspace of on shell solutions.
Consider a Lagrangian density given by.

### Kaluza–Klein theory

Kaluza–KleinKaluza–Klein theoriesKaluza-Klein
One possible way of unifying the electromagnetic and gravitational Lagrangians (by using a fifth dimension) is given by Kaluza-Klein theory.
Next, one takes this scalar curvature as the Lagrangian density, and, from this, constructs the Einstein–Hilbert action for the bundle, as a whole.

### Hamiltonian field theory

Covariant Hamiltonian field theoryHamiltonian densitycovariant (polysymplectic) Hamiltonian field theory
It is a formalism in classical field theory alongside Lagrangian field theory, and has applications in quantum field theory also.

### Einstein–Hilbert action

Einstein-Hilbert actionEinstein–Hilbert LagrangianEinstein-Hilbert Lagrangian
The integral of is known as the Einstein-Hilbert action.
When a cosmological constant Λ is included in the Lagrangian, the action:

### Gauss's law for gravity

Gauss's lawfor gravityGauss' law for gravity
which yields Gauss's law for gravity.
The Lagrangian density for Newtonian gravity is

### Noether's theorem

Noether currentNoether chargeNoether theorem
The action of a physical system is the integral over time of a Lagrangian function (which may be an integral over space of a Lagrangian density function), from which the system's behavior can be determined by the principle of least action.

### Kinetic term

kinetic
In physics, a kinetic term is the part of the Lagrangian that is bilinear in the fields (and for nonlinear sigma models, they are not even bilinear), and usually contains two derivatives with respect to time (or space); in the case of fermions, the kinetic term usually has one derivative only.

### Stress–energy tensor

energy–momentum tensorenergy-momentum tensorstress-energy tensor
:The last tensor is the energy momentum tensor and is defined by
where is the nongravitational part of the action, is the nongravitational part of the Lagrangian density, and the Euler-Lagrange equation has been used.

### Electromagnetic tensor

electromagnetic field tensorfield strength tensorelectromagnetic field strength tensor
:Additionally, we can package the E and B fields into what is known as the electromagnetic tensor F_{\mu\nu}. where is the electromagnetic tensor, D is the gauge covariant derivative, and is Feynman notation for with where A_\sigma is the electromagnetic four-potential.
This means the Lagrangian density is

### Scalar field theory

scalar fieldscalar fieldsscalar
where \mathcal{L} is known as a Lagrangian density;

### Lagrangian system

Lagrangianconfiguration spaceLagrangian density
(or, simply, a Lagrangian) of order

### Fermionic field

Dirac fieldfermion fieldfermionic
The Lagrangian density for a Dirac field is:
Since linear combinations of these quantities are also Lorentz invariant, this leads naturally to the Lagrangian density for the Dirac field by the requirement that the Euler–Lagrange equation of the system recover the Dirac equation.

### Quantum electrodynamics

QEDquantum electrodynamicelectromagnetic
The Lagrangian density for QED is:
The QED Lagrangian for a spin-1/2 field interacting with the electromagnetic field is given in natural units by the real part of

### Quantum chromodynamics

QCDQuantum Chromodynamics (QCD)quantum chromodynamic
The Lagrangian density for quantum chromodynamics is:
The dynamics of the quarks and gluons are controlled by the quantum chromodynamics Lagrangian.

### Gauge covariant derivative

covariant derivative(gauge) covariant derivative
where is the electromagnetic tensor, D is the gauge covariant derivative, and is Feynman notation for with where A_\sigma is the electromagnetic four-potential.
:and in the QED Lagrangian is therefore gauge invariant, and the gauge covariant derivative is thus named aptly.

### Gluon field strength tensor

gluon field tensor
n = 1, 2, ...6 counts the quark types, and is the gluon field strength tensor.
Characteristic of field theories, the dynamics of the field strength are summarized by a suitable Lagrangian density and substitution into the Euler–Lagrange equation (for fields) obtains the equation of motion for the field.

### Degrees of freedom (physics and chemistry)

degrees of freedomdegree of freedomdegrees of freedom (
Lagrangian mechanics is used for discrete particles each with a finite number of degrees of freedom.

### Spacetime

space-timespace-time continuumspace and time
In field theory, the independent variable is replaced by an event in spacetime (x, y, z, t), or more generally still by a point s on a manifold.

### Manifold

manifoldsboundarymanifold with boundary
In field theory, the independent variable is replaced by an event in spacetime (x, y, z, t), or more generally still by a point s on a manifold.

### Equations of motion

equation of motionUniformly accelerated motionSUVAT equations
The dependent variables (q) are replaced by the value of a field at that point in spacetime so that the equations of motion are obtained by means of an action principle, written as:


text:
# Property of Jacobian Determinant

• I

## Main Question or Discussion Point

We can denote the jacobian of a vector map ##\pmb{g}(\pmb{x})## by ##\nabla \pmb{g}##, and we can denote its determinant by ##D \pmb{g}##. We were asked to prove that

##\sum_j \frac{\partial ~ {cof}(D \pmb{g})_{ij}}{\partial x_j} = 0##

generally holds so long as the ##g_i## are suitably differentiable not too long ago. Looking around, this property is mentioned in passing in papers here and there. Does this result go by a headword that I can look up. Like a theorem name of some sort? It is rumored to be an essential property for things like degree theory and the brouwer fixed point theorem.

Last edited:

Related Linear and Abstract Algebra News on Phys.org
mathwonk
Homework Helper
i can't really understand your notation, I assume cof stands for cofactor, but since to me a determinant is a number, hence does not have a cofactor, rather a matrix does. I have never seen this inequality in my study of either degree theory or brouwer's fix point theorem, and do not really know what it is saying, but just off the top of my head it looks as if it might follow from the equality of mixed 2nd partials. you might try working it out for n = 2 or 3.

well here is a discussion that gives a reason for it: see p. 2: he calls the general formula he is deriving Jacobi's formula, but this is just a step in the derivation.

also see page 6 in these notes:

https://www.gotohaggstrom.com/Jacobi’s formula for the derivative of a determinant.pdf

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jim mcnamara
You...are absolutely correct, my friend. I meant
## \sum_j \frac{ \partial ~ cof( \nabla \pmb{g} ) }{ \partial x_j } = 0 ~.##
But that aside, the above statement is true. I had already proved it, so I was inquiring its significance. For example, I've seen it in the second page (pg 17) of the following link, The Jacobian Determinant Revisited. Although, I haven't searched around much thereafter. I am familiar with the content you've referred to above, so I think my inquiry is different. Funny thing is that I haven't bothered reading the paper I referenced. Perhaps I should give it a swirl.

Last edited:


text:
## October 27, 2005

### Plasma-Ball Duals of Black Holes

#### Posted by urs

Ofer Aharony and Micha Berkooz are visiting Hamburg. Yesterday they gave talks on recent work.

O. Aharony, S. Minwalla, T. Wiseman
Plasma-Balls in Large $N$ Gauge Theories and Localized Black Holes
hep-th/0507219

The central idea here is a qualitative argument which is supposed to say that in the large $N$ limit of $\mathrm{SU}\left(N\right)$ gauge theories with a first order confining/deconfining phase transition the free energy – and hence the pressure – of the deconfining phase should pass through 0 close to the phase transition.

The basis for this is the observation that the free energy of the confining phase scales like 0th powers of $N$, while that of the deconfining phase scales with ${N}^{2}$. Hence for both to match at the phase transition point the free energy of the deconfining phase is imagined to be of the form

(1)${Z}_{\mathrm{deconf}}=f\left(\rho \right){N}^{2}\phantom{\rule{thinmathspace}{0ex}},$

where $\rho$ is the energy density and $f\left(\rho \right)$ is a function that becomes at least very small close to the transition point ${\rho }_{\mathrm{crit}}$. Since $Z$ should probably also be monotonic it is argued to be plausible that it actually goes through 0.

Aharony, Minwalla and Wiseman assume that this is the case. They argue that therefore close to the critical density the pressure vanishes and expect this to result in the existence of stable bubbles of quark-gluon plasma.

Given that idea, it is possibly sort of natural to suspect that these plasma balls might be dual, under AdS/CFT-like dualities, to certain black holes in a dual gravity theory.

A list of qualitative and order-of-magnitude consistency checks of this proposal is then disucssed. For instance it is imagined that Hawking radiation on the gravity side is dual to what is called ‘hadronization’ for the plasma balls. This is the process by which a piece of quark-gluon plasma condeses to a hadron which is then spit out of the plasma ball.

By this process both the black hole and the plasma ball are thought to eventually shrink (even though they are ‘classically stable’, which on the plasma ball side corresponds to the vanishing of its internal pressure.) One point of the paper is that this gives the apparently first candidate for a dual description of black holes whose horizon size is small compared to the curvature of the ambient spacetime and the idea is to study such small black holes using small dual plasma balls.

There is also some computer simulation involved in doing so, but I don’t really know anything about that.

After Ofer Aharony’s talk Micha Berkooz reported on

M. Berkooz, D. Chung, T. Volansky
Constraining Modular Inflation in the MSSM from Giant Q-Ball Formation
hep-ph/0507218

I can only give a very rough impression of that work, since I was not able to really follow much of the details.

The motivation of this work is to see if among the many scalar fields that appear in the minimally supersymmetrically extended standard model (MSSM), some qualify as interesting candidates for the still elusive inflaton field, which is thought to have provided the energy density that drove the suspected inflationary early expansive period of our universe.

Roughly, there are certain such fields which have ‘flat directions’, meaning that the potential of the theory does not change when the value of these fields is changed. Some of them apparently also have an ‘accidental’ $U\left(1\right)$-symmetry and hence carry a $U\left(1\right)$-charge, called $Q$. Somehow there is an established concept for such a situation, and certain soliton-like solutions to the equations of motions of these fields are known as Q-balls.

The authors now investigated in how far such $Q$-balls could provide the right properties to qualify, as I said, as a source of energy density driving cosmological inflation. Unfortunately I cannot honestly report on the details of their findings.

Posted at October 27, 2005 6:49 PM UTC

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# Free Digital Painting Resources

http://www.ctrlpaint.com/
http://sakimichan.blogspot.ca/2011/04/eye-references.html (not bad references for eyes)
http://robaato.deviantart.com/gallery/34285302 (A collection of tutorials for digital painting especially cell shading and comics/ very stylized though)
http://browse.deviantart.com/resources/tutorials/digiart/dpadigi/corelpainter/#/d45trc7 (a collection of corel painter tutorials)
http://conceptart.org/forums/showthread.php?233782-Lane-s-Sketchbook/page7 (this ones cool this guy posts animated frame by frames of his works so you see exactly how he did each piece.)

# VP 2

1953, Robert Rauschenberg “Erased De Kooning Drawing”
“My choices consist in choosing what questions to ask”

Cage: Mushroom Haiku/Lecture on Nothing
Cage: Norton Lectures
What is a concept?
What makes something art?

What functions can art have?
Smithson/Holt “Swamp”
Smithson, Hotel Palenque
(Text and Video, video is bootleg though, not original quality. obviously)

John Baldassari, I Will Not Make Any More Boring Art
Sentences on Conceptual Art (1968)
Sol Lewitt

1) Conceptual Artists are mystics rather than rationalists. They leap to conclusions that logic cannot reach.
2) Rational judgments repeat rational judgments.
3) Illogical judgments lead to new experience.
4) Formal art is essentially rational.
5) Irrational thoughts should be followed absolutely and logically.
6) If the artist changes his mind midway through the execution of the piece he compromises the result and repeats past results.
7) The artist’s will is secondary to the process he initiates from idea to completion. His willfulness may only be ego.
8) When words such as painting and sculpture are used, they connote a whole tradition and imply a consequent acceptance of this tradition, thus placing limitations on the artist who would be reluctant to make art that goes beyond the limitations.
9) The concept and idea are different. The former implies a general direction while the latter is the component. Ideas implement the concept.
10) Ideas alone can be works of art; they are in a chain of development that may eventually find some form. All ideas need not be made physical.
11) Ideas do not necessarily proceed in logical order. They may set one off in unexpected directions but an idea must necessarily be completed in the mind before the next one is formed.
12) For each work of art that becomes physical there are many variations that do not.
13) A work of art may be understood as a conductor from the artists’ mind to the viewers. But it may never reach the viewer, or it may never leave the artists’ mind.
14) The words of one artist to another may induce a chain of ideas, if they share the same concept.
15) Since no form is intrinsically superior to another, the artist may use any form, from an expression of words (written or spoken) to physical reality, equally.
16) If words are used, and they proceed from ideas about art, then they are art and not literature, numbers are not mathematics.
17) All ideas are art if they are concerned with art and fall within the conventions of art.
18) One usually understands the art of the past by applying the conventions of the present thus misunderstanding the art of the past.
19) The conventions of art are altered by works of art.
20) Successful art changes our understanding of the conventions by altering our perceptions.
21) Perception of ideas leads to new ideas.
22) The artist cannot imagine his art, and cannot perceive it until it is complete.
23) One artist may misperceive (understand it differently from the artist) a work of art but still be set off in his own chain of thought by that misconstruing.
24) Perception is subjective.
25) The artist may not necessarily understand his own art. His perception is neither better nor worse than that of others.
26) An artist may perceive the art of others better than his own.
27) The concept of a work of art may involve the matter of the piece or the process in which it is made.
28) Once the idea of the piece is established in the artist’s mind and the final form is decided, the process is carried out blindly. There are many side effects that the artist cannot imagine. These may be used as ideas for new works.
29) The process is mechanical and should not be tampered with. It should run its course.
30) There are many elements involved in a work of art. The most important are the most obvious.
31) If an artist uses the same form in a group of works and changes the material, one would assume the artist’s concept involved the material.
32) Banal ideas cannot be rescued by beautiful execution.
33) It is difficult to bungle a good idea.
34) When an artist learns his craft too well he makes slick art.
35) These sentences comment on art, but are not ar </p> NOTES

Chris Burden, 1972,Shoot

Josef Beuys, 1974 I Like America and America Likes Me

Vito Acconci, Following Piece

and Seedbed

Bruce Nauman “Walking Around the Studio in an Exaggerated Manner”

Orlan

Yoko Ono Cut Piece

Yves Klein Anthropometry of the Blue Epoch

Allan Kaprow, Yard, Happening(s)

Philosophical Theory and Sources.

Existentialism: Simone de Beauvoir, Jean-Paul Sartre, Albert Camus, Franz Kafka, Søren Kierkegaard,Friedrich Nietzsche

Structuralism: Ferdinand de Saussure (pre-structuralist linguist, Prague and Moscow Schools of Linguistics along with Jakobson), Roman Jakobson (linguist), Claude Levi-Strauss (anthropologist), Jacques Lacan (psychoanalyst), Michel Foucault (historian), Roland Barthes (literary critic), Maurice Merleau-Ponty (phenomenoligist),Louis Althusser (Marxist theory)

A Splattering of Vanity

Surrealism:Impressions de la Haute Mongolie-Hommage a Raymond Roussel

Modernism

Performance/ Body Art (a brief history) contains graphic content, beware

Situationist International

Vienna Aktionists also highly graphic and violent

Systems Art

The Feminist Film Movement

*I Love America and America Loves Me

Dennis Oppenheim

Smithson/Holt “Swamp”
Smithson, Hotel Palenque
(Text and Video, video is bootleg though, not original quality. obviously)

Hans Haacke:
Real Time Social System
and experimental structures

Yvonne Rainer, a movement in herself

did anyone notice how many of these people find their roots in modern music practice???

see Time lecture above and check out
Pauline Oliveros

along with La Monte Young, John Cage, Yoko Ono, Nam June Paik, and Fluxus in general (if you haven’t already)
how many ways are these people related? who else was hanging around?

(Bas Jan Alder, I’m Too Sad To Tell You)
Yves Klein, Leap into the Void
Keith Boadwee, Leap Into the Yard

Time, Procedure, and Notation

Jackson Mac Lowe, sound poet

The Black Tarantula Crossword Gathas

Notation…

listen

previous to Beethoven’s time (1770-1827) people notated music without volume and articulation indications:

specificity, as an issue for communication

Earle Brown, Composer

Laban Notation for Human Movement

Cornelius Cardew, Composer, Designer, Critic

(new version)

AMM

movement, time, concept, relationship

Ludo Mich, outlaw

What Does the Word “Rhythm” Mean?

What is TIME?

and how does it move?
is it a line? a circle?

and what is it used for?

and how is this movement perceived?

and to what extent are time’s movements universal,
or to what extent are they our own personal,
or our various cultures’ constructions
and how does this affect our art making?

how can the light recorded on the photographic plate during an exposure be considered a record of time?

Is it possible to relate our personal frames of reference
with respect to time,
with the vast orders of magnitude existing across time and space?

## Seconds

Orders of magnitude (time)
Factor (s) Multiple Symbol Definition Comparative examples & common units Orders of magnitude
10−44 tP Planck time is the unit of time of the natural units system known as Planck units. Planck time = $\sqrt{\hbar G/c^5}\approx 5.4 \times 10^{-44} \text{ s}$. 10−44 s
10−24 1 yoctosecond ys[1] Yoctosecond, (yocto- + second), is one quadrillionth (in the long scale) or one septillionth (in the short scale) of a second. 0.3 ys: mean life of the W and Z bosons.[2][3][a]
0.5 ys: time for top quark decay, according to the Standard Model.
1 ys: time taken for a quark to emit a gluon.
23 ys: half-life of 7H.
1 ys and less, 10 ys, 100 ys
10−21 1 zeptosecond zs Zeptosecond, (zepto- + second), is one sextillionth of one second (short scale). 7 zs: half-life of helium-9’s outer neutron in the second nuclear halo.
17 zs: approximate period of electromagnetic radiation at the boundary between gamma rays and X-rays.
300 zs: approximate typical cycle time of X-rays, on the boundary between hard and soft X-rays.
500 zs: current resolution of tools used to measure speed of chemical bonding[4]
1 zs, 10 zs, 100 zs
10−18 1 attosecond as 12 attoseconds: shortest measured period of time.[5] 1 as, 10 as, 100 as
10−15 1 femtosecond fs cycle time for 390 nanometre light, transition from visible light to ultraviolet 1 fs, 10 fs, 100 fs
10−12 1 picosecond ps 1 ps: half-life of a bottom quark
4 ps: Time to execute one machine cycle by an IBM Silicon-Germanium transistor
1 ps, 10 ps, 100 ps
10−9 1 nanosecond ns 1 ns: Time to execute one machine cycle by a 1GHz microprocessor
1 ns: Light travels 12 inches (30 cm)
1 ns, 10 ns, 100 ns
10−6 1 microsecond µs sometimes also abbreviated µsec
1 µs: Time to execute one machine cycle by an Intel 80186 microprocessor
4–16 µs: Time to execute one machine cycle by a 1960s minicomputer
1 µs, 10 µs, 100 µs
10−3 1 millisecond ms 4–8 ms: typical seek time for a computer hard disk
50–80 ms: Blink of an eye
150–300 ms: Human reflex response to visual stimuli
1 ms, 10 ms, 100 ms
10−2 1 centisecond cs
100 1 second s 1 s: 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium-133 atom.[6]
60 s: 1 minute
1 s, 10 s, 100 s
103 1 kilosecond
(16.7 minutes)
ks 3.6 ks: 3600 s or 1 hour
86.4 ks: 86 400 s or 1 day
604.8 ks: 1 week
103 s, 104 s, 105 s
106 1 megasecond
(11.6 days)
Ms month = 2.6 x 106 s
year = 31.6 Ms = 107.50 s
106 s, 107 s, 108 s
109 1 gigasecond
(32 years)
Gs century = 3.16 Gs ≈ 3.16 × 109 s
millennium = 31.6 Gs ≈ 3.16 × 1010 s
109 s, 1010 s, 1011 s
1012 1 terasecond
(32 000 years)
Ts eon = 31.6 Ts ≈ 3.16 × 1013 s 1012 s, 1013 s, 1014 s
1015 1 petasecond
(32 million years)
Ps aeon = 31.6 Ps ≈ 3.16 × 1016 s 1015 s, 1016 s, 1017 s
1018 1 exasecond
(32 billion years)
Es 0.43 Es ≈ the approximate age of the Universe 1018 s, 1019 s, 1020 s
1021 1 zettasecond
(32 trillion years)
Zs 1021 s, 1022 s, 1023 s
1024 1 yottasecond
Ys 1024 s, 1025 s, 1026 s and more
Years
Orders of magnitude (time)
Factor (a) Multiple common units orders of magnitude
10−50 Planck time, the shortest physically meaningful interval of time ≈ 1.71 × 10−50 a 10−50 a
10−24 1 yoctoannum 1 ya and less, 10 ya, 100 ya
10−21 1 zeptoannum 1 za, 10 za, 100 za
10−18 1 attoannum 1 aa, 10 aa, 100 aa
10−15 1 femtoannum 1 fa, 10 fa, 100 fa
10−12 1 picoannum 1 pa, 10 pa, 100 pa
10−9 1 nanoannum 1 second = 3.17 × 10-8 a ≈ 10-7.50 a 1 na, 10 na, 100 na
10−6 1 microannum 1 minute = 1.90 × 10-6 a
1 hour = 1.40 × 10-4 a
1 ua, 10 ua, 100 ua
10−3 1 milliannum 1 day = 2.73 × 10-3 a
1 week = 1.91 × 10-2 a
1 ma, 10 ma, 100 ma
100 1 annum 1 average year = 1 annum (= 365.24219 SI days)
century = 100 anna
1 a, 10 a, 100 a
103 1 kiloannum millennium = 1000 anna 103 a, 104 a, 105 a
106 1 megaannum epoch = 1,000,000 anna 106 a, 107 a, 108 a
109 1 gigaannum aeon = 1,000,000,000 anna
13.7 Ga = 1.37×1010 a ≈ 13.7 billion years, the approximate age of the Universe
109 a, 1010 a, 1011 a
1012 1 teraannum 1012 a, 1013 a, 1014 a
1015 1 petaannum 1015 a, 1016 a, 1017 a
1018 1 exaannum 1018 a, 1019 a, 1020 a
1021 1 zettaannum 1021 a, 1022 a, 1023 a
1024 1 yottaannum 1024 a, 1025 a, 1026 and more

The pages linked in the right-hand column contain lists of times that are of the same order of magnitude (power of ten).

Rows in the table represent increasing powers of a thousand (3 orders of magnitude).

Conversion from year to second is year × 31 557 600 using the Julian year.

Conversion from log10 year to log10 second is approximately log10 year + 7.50. Example conversion; 1 year = 100 year = 100 + 7.50 seconds = 100.50 + 7s = 3.16 * 107s.

(the clock of the long now will keep time on a 10,000 year cycle
this is the first prototype,
and is on exhibit in the London Science Museum…

what art forms organize time?
what use time? and how?

((Here is a film/sound composition
or is it a light/music composition as an example,
but what is it that makes it a composition?
and how is this “composition” articulated
(how is it made, what instructions are used to create it?)
What is being organized in what media?
hint: it has to do with the subject of this seminar))

and what about Change Ringing? How does this ancient practice relate time and space? How does it structure time and why was this method of organizing time developed? What are the relationships here between the time structure created and the materials being employed to create it? How does this relate to Algorithmic Composition?

guide to the church bells of prague (incidental trivia related to the above topic)

# VP test

Please note: Module handbook is located above. The handbook details the submission dates, requirements, and assessment criteria for this module. Also included are the dates for each meeting. Attendance to module meetings is required. Attendance and participation in critiques is directly reflected in your grade.

That being understood, lets proceed to a discussion of:

Eames (see below)

Powers of Ten

Robert Irwin: Primaries and Secondaries

Design Q&A

(above: Ellsworth Kelly, title unknown)

Sol LeWitt, Wall Drawings (algorithmic composition)

Sigmar Polke

(below) paintings:

Richard Long 4 Circles

(at least)

below: Bridget Riley, titles unknown)

# Self Directed Project: Example

Predevelopment & Research
My work for this assignment is actually also a final piece in a series of my previous work, and it is actually their culmination – it is what these previous works were supposed to represent. From the start I wished to create a piece of light-art, but also with a mix of a kinetic scultpure or object. I wished to combine these two elements to create a visual instrument that is interactive.
In this respect, I was influenced largely by the works of Olaffur Eliasson, who although is not
creating very similar object is very stemmed in the experience itself. He works a lot with
geometrical shapes, and the properties of objects themselves. He creates his art by playing with
forms and light in order to create stunning experiences. It is hard to comment on his direct work process though, as he employs a studio full of people who help him complete his amazing works.

I also enjoyed the works of a young american artist, Joshua Kirsch who creates interactive lightart/kinetic objects.

His works, particuarly Concentricity 96 as seen above have inspired me, although the basic shape of my piece was created long ago before I found him. He works with quite advanced mechanics and electronics, standard of which I could not replicate, but anyhow seeing his work I decided that my work should definitely be interactive.
The previous works that this final piece is a culmination of are two objects, one is a small copper jewelry piece, which I call Rotator 1. Its about 10cm in diameter, and it already reflects the basic shape of my future work.

Later, I was able to work with some larger metal plates, and so I decided that I could make my work bigger, perhaps prepare a skeleton for further work. The Rotator 2 already was about 1,25m in diameter and made of cor-ten metal. However the whole structure was too heavy. I would not be able to get it moving, and even if so it would be quite dangerous with this mass of metal

Statement of Intent
In my project I will research several artist and techniques in order to create an object that is both visual and interactive. This piece will be a light/kinetic sculpture with a variety of possible uses – as aninstallation piece/projection area/or a music visualisation. Foremostly
though I like to describe it as a ‘visual instrument’.
It will be made out of wood, I also need a suitable motor and around 3
meters of LED light strips.
The final production will be in the form of photodocumentation and video.

This project has involved a lot of drawing, directly or indirectly. Sketching and drawing were at the center, although it wasn’t usually on paper, but on the woodpieces themselves that would finally be cut.

I enjoyed working on this project a lot because it combined a wide variety of techniques and led me to discover and learn more.

Sketches & Development

Actual Development
I wished for my piece to be interactive and rotating, so I had several
constrains that I need to solve or get around. The first was finding a
suitable motor that would be powerful enough to rotate my piece, yet
not too powerful to work with.
The solution came quite quickly with the discovery of an old washing
machine.

And so, the very first challenge was removing it from the box.

The motor needed to be plugged in! Luckily I was able to configure
the original cord of the washing machine.

And use it to plug the motor into power directly.

With the motor prepared, I now knew how should I continue with my
production. The motor was a primary constraint, as everything would
stem from it. There were several important things that would be built
on it – the rotating power connectors that would power the LED lights
on the ends and a systém of attaching the whole piece. Next came the
basic designing.

First, were the ‘wings’. Their size and shape was calculated to be
exact, and to have about 20cm of space in separation.

In further preparation, the whole shapes was drawn onto a board.

The wings are cut and put into the prepared shape.

Next were the middle pieces that neatly fall into place.

The middle pieces would need to be connected together strongly with
wooden circles and glue.

Adding the central parts to hold the structure.

The rotation is achieved.

Gluing process continues.

In the end only one screw was enough to hold the wings, even when
rotating.

The base is done. Down you can see the two wooden plates that will
hold the structure on the end of the motor with several screws.

Standard and ‘Shuriken’ mode

The most complicated element is probably the power connection. It
will be led through cables that will touch the rotating rod. On the rod
there will be strips of tape that will both hold and insulate two metal
strips. The curved ends of the woodpieces will be filled with wire that
will touch the metal strips. Cables will lead from the metal strips
( under them ) and connect to the added rotating structure, as they
rotate together with the rod.

Time for the paint-job.

Paintjob is done. Next : sticking the LED strips. They already came
with 3M tape on the other side, so they were ready to go.

The connection travels through the wooden pieces through the insulated metal
plates and onwards through cables that rotate with the structure.

The connection travels through the wooden pieces through the insulated metal
plates and onwards through cables that rotate with the structure.

The rotating power connectors are finished.

Time to solder the cables to the LED strips. Only one of the strips had
the cables pre-attached.

The base is finished, time for wiring.

First connection – it is working!

Testing the light intensity.

FINISHED PIECE