eggs
763839
Golden Eggs and Hyperbolic Discounting
Hyperbolic discount functions induce dynamically inconsistent preferences, implying a motive for consumers to constrain their own future choices. This paper analyzes the decisions of a hyperbolic consumer who has access to an imperfect commitment technology: an illiquid asset whose sale must be initiated one period before the sale proceeds are received. The model predicts that consumption tracks income, and the model explains why consumers have asset specific marginal propensities to consume. The model suggests that financial innovation may have caused the ongoing decline in U. S. savings rates, since financial innovation in creases liquidity, eliminating commitment opportunities. Finally, the model implies that financial market innovation may reduce welfare by providing aEURoetoo muchaEUR liquidity.
David I Laibson
24732575
Eggs in Early Complementary Feeding and Child Growth: A Randomized Controlled Trial
This rigorously conducted trial showed that when offered early in complementary feeding, the food based intervention of eggs produced a large effect size on child growth. BACKGROUND: Eggs are a good source of nutrients for growth and development. We hypothesized that introducing eggs early during complementary feeding would improve child nutrition. METHODS: A randomized controlled trial was conducted in Cotopaxi Province, Ecuador, from March to December 2015. Children ages 6 to 9 months were randomly assigned to treatment (1 egg per day for 6 months [n 83] and control (no intervention [n 80] groups. Both arms received social marketing messages to encourage participation in the Lulun Project (lulun meaning "egg" in Kichwa) All households were visited once per week to monitor morbidity symptoms, distribute eggs, and monitor egg intakes (for egg group only) Baseline and end point outcome measures included anthropometry, dietary intake frequencies, and morbidity symptoms. RESULTS: Mothers or other caregivers reported no allergic reactions to the eggs. Generalized linear regression modeling showed the egg intervention increased length for age z score by 0.63 (95% confidence interval [CI] 0.38 0.88) and weight for age z score by 0.61 (95% CI, 0.45 0.77) Log binomial models with robust Poisson indicated a reduced prevalence of stunting by 47% (prevalence ratio [PR] 0.53; 95% CI, 0.37 0.77) and underweight by 74% (PR, 0.26; 95% CI, 0.10 0.70) Children in the treatment group had higher dietary intakes of eggs (PR, 1.57; 95% CI, 1.28 1.92) and reduced intake of sugar sweetened foods (PR, 0.71; 95% CI, 0.51 0.97) compared with control. CONCLUSIONS: The findings supported our hypothesis that early introduction of eggs significantly improved growth in young children. Generally accessible to vulnerable groups, eggs have the potential to contribute to global targets to reduce stunting.
Pediatrics
Lora L Iannotti Chessa K Lutter Christine P Stewart Carlos Andres Gallegos Riofrio Carla Malo Gregory A Reinhart Ana M Palacios Celia Karp Melissa Chapnick Katherine Cox William F Waters
35191304
Mechanisms of Aneuploidy in Human Eggs.
Eggs and sperm develop through a specialized cell division called meiosis. During meiosis, the number of chromosomes is reduced by two sequential divisions in preparation for fertilization. In human female meiosis, chromosomes frequently segregate incorrectly, resulting in eggs with an abnormal number of chromosomes. When fertilized, these eggs give rise to aneuploid embryos that usually fail to develop. As women become older, errors in meiosis occur more frequently, resulting in increased risks of infertility, miscarriage, and congenital syndromes, such as Down's syndrome. Here, we review recent studies that identify the mechanisms causing aneuploidy in female meiosis, with a particular emphasis on studies in humans.
Trends in cell biology
Alexandre Webster Melina Schuh
217463139
The Chemistry of Eggs and Egg Products
Eunice C Y Li-Chan William Powrie Shuryo Nakai
18973131
Association between the number of eggs and live birth in IVF treatment: an analysis of 400 135 treatment cycles.
BACKGROUND While live birth is the principal clinical outcome following in vitro fertilization (IVF) treatment, the number of eggs retrieved following ovarian stimulation is often used as a surrogate outcome in clinical practice and research. The aim of this study was to explore the association between egg number and live birth following IVF treatment and identify the number of eggs that would optimize the IVF outcome. METHODS Anonymized data on all IVF cycles performed in the UK from April 1991 to June 2008 were obtained from the Human Fertilization and Embryology Authority (HFEA) We analysed data from 400 135 IVF cycles. A logistic model was fitted to predict live birth using fractional polynomials to handle the number of eggs as a continuous independent variable. The prediction model, which was validated on a separate HFEA data set, allowed the estimation of the probability of live birth for a given number of eggs, stratified by age group. We produced a nomogram to predict the live birth rate (LBR) following IVF based on the number of eggs and the age of the female. RESULTS The median number of eggs retrieved per cycle was 9 [inter quartile range (IQR) 6 13] The overall LBR was 21.3% per fresh IVF cycle. There was a strong association between the number of eggs and LBR; LBR rose with an increasing number of eggs up to ~15, plateaued between 15 and 20 eggs and steadily declined beyond 20 eggs. During 2006 2007, the predicted LBR for women with 15 eggs retrieved in age groups 18 34, 35 37, 38 39 and 40 years and over was 40, 36, 27 and 16% respectively. There was a steady increase in the LBR per egg retrieved over time since 1991. CONCLUSION The relationship between the number of eggs and live birth, across all female age groups, suggests that the number of eggs in IVF is a robust surrogate outcome for clinical success. The results showed a non linear relationship between the number of eggs and LBR following IVF treatment. The number of eggs to maximize the LBR is ~15.
Human reproduction
Sesh Kamal Sunkara Vivian Rittenberg Nick Raine-Fenning Siladitya Bhattacharya Javier Zamora Arri Coomarasamy
5349529
Salmonella and Eggs: From Production to Plate
Salmonella contamination of eggs and egg shells has been identified as a public health concern worldwide. A recent shift in consumer preferences has impacted on the egg industry, with a push for cage free egg production methods. There has also been an increased desire from consumers for raw and unprocessed foods, potentially increasing the risk of salmonellosis. In response to these changes, this review explores the current literature regarding Salmonella contamination of eggs during the production processing through to food handling protocols. The contamination of eggs with Salmonella during the production process is a complex issue, influenced by many variables including flock size, flock age, stress, feed, vaccination, and cleaning routines. Currently there is no consensus regarding the impact of caged, barn and free range egg production has on Salmonella contamination of eggs. The literature regarding the management and control strategies post collection, during storage, transport and food handling is also reviewed. Pasteurisation and irradiation were identified as the only certain methods for controlling Salmonella and are essential for the protection of high risk groups, whereas control of temperature and pH were identified as potential control methods to minimise the risk for foods containing raw eggs; however, further research is required to provide more detailed control protocols and education programs to reduce the risk of salmonellosis from egg consumption.
International journal of environmental research and public health
Harriet Whiley Kirstin E Ross
38167311
Oogenesis in teleosts: how eggs are formed.
One of the major objectives of the aquaculture industry is the production of a large number of viable eggs with high survival. Major achievements have been made in recent years in improving protocols for higher efficiency of egg production and viability of progeny. Main gaps remain, however, in understanding the dynamic processes associated with oogenesis, the formation of an egg, from the time that germ cells turn into oogonia, until the release of ova during spawning in teleosts. Recent studies on primordial germ cells, yolk protein precursors and their processing within the developing oocyte, the deposition of vitamins in eggs, structure and function of egg envelopes and oocyte maturation processes, further reveal the complexity of oogenesis. Moreover, numerous circulating endocrine and locally acting paracrine and autocrine factors regulate the various stages of oocyte development and maturation. Though it is clear that the major regulators during vitellogenesis and oocyte maturation are the pituitary gonadotropins (LH and FSH) and sex steroids, the picture emerging from recent studies is of complex hormonal cross talk at all stages between the developing oocyte and its surrounding follicle layers to ensure coordination of the various processes that are involved in the production of a fertilizable egg. In this review we aim at highlighting recent advances on teleost fish oocyte differentiation, maturation and ovulation, including those involved in the degeneration and reabsorption of ovarian follicles (atresia) The role of blood borne and local ovarian factors in the regulation of the key steps of development reveal new aspects associated with egg formation.
General and comparative endocrinology
Esther Lubzens Graham Young Julien Bobe Joan Cerda
38588941
Eggs: the uncracked potential for improving maternal and young child nutrition among the world's poor.
Eggs have been consumed throughout human history, though the full potential of this nutritionally complete food has yet to be realized in many resource poor settings around the world. Eggs provide essential fatty acids, proteins, choline, vitamins A and B12 selenium, and other critical nutrients at levels above or comparable to those found in other animal source foods, but they are relatively more affordable. Cultural beliefs about the digestibility and cleanliness of eggs, as well as environmental concerns arising from hygiene practices and toxin exposures, remain as barriers to widespread egg consumption. There is also regional variability in egg intake levels. In Latin American countries, on average, greater proportions of young children consume eggs than in Asian or African countries. In China and Indonesia, nutrition education and social marketing have been associated with greater amounts of eggs in the diets of young children, though generally, evidence from interventions is minimal. Homestead chicken and egg production with appropriate vaccination, extension service, and other supports can simultaneously address poverty and nutrition in very poor rural households. With undernutrition remaining a significant problem in many parts of the world, eggs may be an uncracked part of the solution.
Nutrition reviews
Lora L Iannotti Chessa K Lutter David A Bunn Christine P Stewart
145387410
Sex Cells: The Medical Market for Eggs and Sperm
In Sex Cells, Rene Almeling describes in detail the market in what are euphemistically called donated eggs and sperm. She found gender differences not only in pay, but in the framing of the donation as a 'gift' or a 'job. In the market for gametes, eggs are more highly valued than sperm; egg donation is considered a gift of life, while sperm donors are construed as doing a job for which they are paid. To Almeling, the frame is a gendered stereotype of women as 'selfless, caring, and focused on relationships and family' (p. 131) they cannot be seen as selling babies, so their eggs are a 'gift. For sperm donors, the masculine oxymoron was in the juxtaposition of a pleasurable experience (masturbation) with a sometimes alienating job. Yet while sperm donors call themselves fathers and connect to the children born of their sperm, negating the female gestator and social parents, egg donors 'are adamant that they are not mothers' the recipients are the mothers (p. 20) Almeling's extensive, in depth ethnographic research covers the economic, cultural, and structural organization of six donor programs through interviews with 45 staff members, observations of daily practices, and analysis of more than a thousand records. She also conducted 60to 90 minute interviews with 19 egg donors and 20 sperm donors ranging in age from 19 to 46. Sperm donation went from a medical service for infertile heterosexual married couples in the 1950s using fresh sperm, to a commercial enterprise where frozen sperm is sold increasingly to single women and lesbians. The AIDs epidemic in the 1980s increased the market for sperm that could be frozen and the donors tested for several months before it was used. With new in vitro fertilization (IVF) techniques for male infertility, there are fewer heterosexual married couples seeking sperm donation, so the target buyers increasingly are single women and lesbians. The large commercial sperm banks sell donors with profiles and ID releases to meet these clients' demands. The egg donation programs that began in IVF clinics in the 1980s originally were a search for altruistic 'earth mothers. Psychological evaluations were used on the premise that altruism predicted honesty about medical information and compliance with the regimen of hormonal injections. Anonymity was discouraged; some recipients even recruited their own donors. The proliferation of IVF clinics and new techniques has increased the demand for donated eggs for women whose uteruses are intact but whose eggs are defective. There are many applications to be egg donors, but there is a high attrition rate. The ideal egg donor, according to agency staffs, is either a physically attractive college graduate or a caring mother. The ideal sperm donor is a tall college student with consistently high sperm counts. Agencies also look for ethnic, racial, and religious diversity, and may pay these donors more. The extensive testing that potential egg donors go through and the attrition rate reduce actual donors to 20 percent of the original pool. Sperm banks reject more than 90 percent of applicants, most on the basis of their sperm count. In the course of profiling, the actual sex cells (sperm, eggs) that are being sold turn into gendered people, even though few of the donors' personality characteristics are inheritable. Egg donation involves self administered injections of fertility drugs to stimulate egg production and surgical egg retrieval. In addition, the donors are monitored with blood tests and ultrasounds. They may have to travel to the recipient's city, but sometimes that is a bonus vacation. Side effects can be severe or at the least, discomforting hyperstimulation, infection, bleeding, anesthetic complications, and pain but donors prepare themselves with discussions with medical professionals and online or library research. The majority (80 percent) were willing to undergo at least one more cycle; many planned to donate several more times. The donors get paid thousands of dollars no matter how many eggs they produce, but they usually Reviews 379
Judith Lorber
83515354
Salmonella Enteritidis in shell eggs: Current issues and prospects for control
Foodborne illness caused by Salmonella spp. is a worldwide problem. In the United States Salmonella Enteritidis is the second most commonly isolated serotype from human illness, and is known to be strongly associated with shell eggs and egg containing products. Eggs can become contaminated internally either by penetration through the shell or directly during formation in the reproductive tract. This review begins with a brief account of the physiology of egg production and the various physical and chemical barriers the egg possesses to prevent bacterial contamination. Factors involved in vertical and horizontal transmission of S. Enteritidis are examined, as well as the role of forced molt in colonization of the hen. Pre and post harvest mitigation strategies are also discussed.
Zoe R Howard Corliss A O'Bryan Philip G Crandall Steven C Ricke