Contract-theoretic approaches to wages and displacement, commentary

Wages

Subprime outcomes: turmoil in the mortgage market

Until 2007, few Americans had probably heard the word “subprime” - including many homeowners who would come to learn that their own mortgage was a subprime mortgage. Today, subprime mortgages are much discussed because they lie at the center of the turmoil that roiled credit markets in 2007 and 2008.Subprime mortgage

Avian telomere dynamics

Telomeres, the repetitive DNA sequences that cap eukaryotic chromosomes, are thought to play an important role in linking life conditions and senescence. In vertebrate somatic cells, telomeres shorten at each cell division, and the rate at which they do so has been linked to cellular and organismal senescence. Although telomeres generally shorten with age in vertebrates, in most species studied there is considerable variation between same age individuals. In this thesis, I examined the telomere dynamics of various avian species, investigating both the causes of variation in telomere length among individuals and what effect this variation has on attributes such as survival rates. Previous studies have shown that most telomere loss occurs in young individuals and it thus makes sense that early life conditions are responsible for much of the inter-individual variation in telomere length. I investigated this idea by studying chick telomere dynamics in a wild population of lesser black-backed gulls Larus fuscus. There was considerable variation in hatching telomere length among individuals and much of this variation was related to circumstances during embryonic growth. Larger hatchlings had shorter telomere lengths, suggesting that embryonic growth rate could have affected telomere attrition. Independent of this trend, males had longer telomeres at hatching than females. Although telomere length did decrease with age post-hatching, these initial variations remained consistent during the initial post-hatching period. The relationship between early life conditions and telomere length was investigated further with a longitudinal study of telomere length in chicks of the European shag Phalacrocorax aritotelis. A previous study on this population of birds had shown that telomere length declines with age within individuals over a period of several years. However no change in telomere length was detected over a period of 11-13 days during the chick period. Body size had no effect on telomere length, but males did have longer telomere than females. These initial chapters investigate telomere length in chicks; however there are very few studies that investigate telomere length over the entire lifespan of long-lived species. I thus next examined the telomere dynamics of two species of long-lived seabird, the northern and southern giant petrels (Macronectes spp.). In both giant petrel species, telomeres were shorter in adults than chicks, but there was no trend for adult telomere length to decrease with age. In southern giant petrels, there was a significant relationship (independent of age and sex) between an individuals telomere length and whether it was still alive 8 years after it was initially sampled. This relationship was not present in northern giant petrels, possibly due to a smaller sample size. The results thus support both the idea that most telomere loss occurs in young individuals and that telomere length may be an indicator of life expectancy. Various methods exist to measure telomeres. As the number of taxa whose telomere dynamics are being studied increases, it becomes increasingly important to know which methods are the best to use and to what extent these methods are applicable across species. These questions were investigated in relation to work conducted on the telomere dynamics of the blue-footed booby Sula nebouxxi. Both the TRF and qPCR techniques were used to measure booby telomeres, but problems arose with both methods. It is possible that these problems occurred because blue-footed boobies have a particularly large amount of interstitial telomeric DNA, although a more detailed analysis of booby telomeres would be necessary to determine this. These findings suggest that standardised methods to measure telomeres cannot necessarily be applied to every new species whose telomere dynamics are studied. The evidence presented here suggests that the study of telomere dynamics can be a very powerful tool for behavioural ecologists. It now seems possible that telomeres might provide both a way of measuring the long-term costs of early life-conditions and a way to measure the quality of an individual. However, further research is still needed to fill in the considerable gaps in our knowledge and fully exploit the potential telomeres have for behavioural ecology

U. S. labor supply in the twenty-first century

The American labor force will be transformed as the twenty-first century unfolds, a change that will confront policymakers and business firms with new challenges and new opportunities. The impending slowdown of labor force growth that will accompany the retirement of the baby boom generation already is playing a central role in national debates over the future solvency of Social Security and Medicare, as well as U.S. immigration policies. But labor supply changes will be influenced by other dimensions as well. In the coming decades, American workers are likely to be, on average, older and better educated than today’s labor force. The globalization of labor markets is already opening new employment opportunities for some Americans and changing the wage rates paid to others. The production technologies and personnel policies adopted by tomorrow’s firms will undoubtedly reflect the numbers and types of workers available for employment.Labor supply ; Baby boom generation

The role of the AP-1 adaptor complex in trafficking between the trans-Golgi Network and endosomal system

The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.Title from title screen of research.pdf file viewed on (November 7, 2006)Includes bibliographical references.Vita.Thesis (Ph. D.) University of Missouri-Columbia 2005.Dissertations, Academic -- University of Missouri--Columbia -- Biological sciences.In Saccharomyces cerevisiae it is generally accepted that there are two routes for trafficking of proteins from the trans-Golgi network (TGN) to the vacuole. One involves direct transport from the TGN to the vacuole. The second involves transport from the TGN to the prevacuolar compartment (PVC) via GGA coated vesicles, followed by PVC to vacuole transport. We propose that there is a third route. This route entails transit from the TGN to the early endosome (EE), followed by delivery to the PVC and vacuole. In support of an alternative route, the processing kinetics of A(F[arrow]A)-ALP are not affected by mutations in the GGA proteins. This is in contrast to proteins that use the GGA pathway, as their delivery to the vacuole is significantly slowed when GGA function is ablated. Further support of an EE itinerary is the observation that A(F[arrow]A)-ALP co localizes with the lipophilic dye, FM4-64 at a time when the dye is associated with the EE. Disruption of the AP-1 vesicle coat complex leads to an accelerated processing of A(F[arrow]A)-ALP. Appending the region of A(F[arrow]A)-ALP that interacts with AP-1 to Cps1p delays its progress to the vacuole. These results are consistent with a model in which A(F[arrow]A)-ALP passes through the EE in transit to the vacuole. A(F[arrow]A)-ALP physically interacts with AP-1, and this interaction delays its delivery to the vacuole. Data presented in this thesis suggests that in Saccharomyces cerevisiae AP-1 functions as a retrieval mechanism from the EE to the TGN

An open future for ecological and evolutionary data?

As part of BioMed Central’s open science mission, we are pleased to announce that two of our journals have integrated with the open data repository Dryad. Authors submitting their research to either BMC Ecology or BMC Evolutionary Biology will now have the opportunity to deposit their data directly into the Dryad archive and will receive a permanent, citable link to their dataset. Although this does not affect any of our current data deposition policies at these journals, we hope to encourage a more widespread adoption of open data sharing in the fields of ecology and evolutionary biology by facilitating this process for our authors. We also take this opportunity to discuss some of the wider issues that may concern researchers when making their data openly available. Although we offer a number of positive examples from different fields of biology, we also recognise that reticence to data sharing still exists, and that change must be driven from within research communities in order to create future science that is fit for purpose in the digital age. This editorial was published jointly in both BMC Ecology and BMC Evolutionary Biology

The clathrin adaptor complex 1 directly binds to a sorting signal in Ste13p to reduce the rate of its trafficking to the late endosome of yeast

Yeast trans-Golgi network (TGN) membrane proteins maintain steady-state localization by constantly cycling to and from endosomes. In this study, we examined the trafficking itinerary and molecular requirements for delivery of a model TGN protein A(F→A)–alkaline phosphatase (ALP) to the prevacuolar/endosomal compartment (PVC). A(F→A)-ALP was found to reach the PVC via early endosomes (EEs) with a half-time of ∼60 min. Delivery of A(F→A)-ALP to the PVC was not dependent on either the GGA or adaptor protein 1 (AP-1) type of clathrin adaptors, which are thought to function in TGN to PVC and TGN to EE transport, respectively. Surprisingly, in cells lacking the function of both GGA and AP-1 adaptors, A(F→A)-ALP transport to the PVC was dramatically accelerated. A 12-residue cytosolic domain motif of A(F→A)-ALP was found to mediate direct binding to AP-1 and was sufficient to slow TGN→EE→PVC trafficking. These results suggest a model in which this novel sorting signal targets A(F→A)-ALP into clathrin/AP-1 vesicles at the EE for retrieval back to the TGN

The US Employment Situation Using the Yale Labor Survey

This study presents the design and results of a rapid-fire survey that collects labor market data for households in the United States. The Yale Labor Survey, or YLS, uses an online panel from YouGov to replicate the Current Population Survey (CPS), which is the source of the government’s monthly household statistics. Questions in the YLS concern current and retrospective employment, hours, and income. Because the YLS draws upon an existing pool of potential respondents, it can generate responses inexpensively and quickly (within 24 hours). Moreover, the YLS can develop new questions in real time to study unusual patterns of work and unemployment during the pandemic. Results from the YLS track those from the CPS over the period of April through June of 2020, with relatively accurate estimates of employment but greater difficulty capturing unemployment. The major issue statistical issue dealt with in this paper is the sample weighting required to overcome the bias in using an online panel

Work in the Time of COVID: Results from the Yale Labor Survey

The Yale Labor Survey (YLS) uses online panels to estimate the state of the US labor market in real time. It is designed to parallel the US government’s monthly labor force survey and present weekly information rapidly and inexpensively. Using an experimental design, the YLS estimates that the US unemployment rate peaked in late April and improved substantially by mid-June. The YLS unemployment rate in mid-June is estimated to be 15%, down about 2 percentage points from mid-May