Extinction and the spatial dynamics of biodiversity

PubMed Central

Jablonski, David

2008-01-01

The fossil record amply shows that the spatial fabric of extinction has profoundly shaped the biosphere; this spatial dimension provides a powerful context for integration of paleontological and neontological approaches. Mass extinctions evidently alter extinction selectivity, with many factors losing effectiveness except for a positive relation between survivorship and geographic range at the clade level (confirmed in reanalyses of end-Cretaceous extinction data). This relation probably also holds during “normal” times, but changes both slope and intercept with increasing extinction. The strong geographical component to clade dynamics can obscure causation in the extinction of a feature or a clade, owing to hitchhiking effects on geographic range, so that multifactorial analyses are needed. Some extinctions are spatially complex, and regional extinctions might either reset a diversity ceiling or create a diversification debt open to further diversification or invasion. Evolutionary recoveries also exhibit spatial dynamics, including regional differences in invasibilty, and expansion of clades from the tropics fuels at least some recoveries, as well as biodiversity dynamics during normal times. Incumbency effects apparently correlate more closely with extinction intensities than with standing diversities, so that regions with higher local and global extinctions are more subject to invasion; the latest Cenozoic temperate zones evidently received more invaders than the tropics or poles, but this dynamic could shift dramatically if tropical diversity is strongly depleted. The fossil record can provide valuable insights, and their application to present-day issues will be enhanced by partitioning past and present-day extinctions by driving mechanism rather than emphasizing intensity. PMID:18695229

An Examination of Business Students' Student Loan Debt and Total Debt

ERIC Educational Resources Information Center

Kuzma, Ann T.; Kuzma, John R.; Thiewes, Harold F.

2010-01-01

Under the current economic environment and its high levels of unemployment, many people are turning to university education to attain higher education or simply to upgrade their skills and avoid continued unemployment. This paper examines student workloads, debt levels, and the debt perceptions of junior- and senior-level College of Business…

Waiting can be an optimal conservation strategy, even in a crisis discipline

PubMed Central

Possingham, Hugh P.; Bode, Michael

2017-01-01

Biodiversity conservation projects confront immediate and escalating threats with limited funding. Conservation theory suggests that the best response to the species extinction crisis is to spend money as soon as it becomes available, and this is often an explicit constraint placed on funding. We use a general dynamic model of a conservation landscape to show that this decision to “front-load” project spending can be suboptimal if a delay allows managers to use resources more strategically. Our model demonstrates the existence of temporal efficiencies in conservation management, which parallel the spatial efficiencies identified by systematic conservation planning. The optimal timing of decisions balances the rate of biodiversity decline (e.g., the relaxation of extinction debts, or the progress of climate change) against the rate at which spending appreciates in value (e.g., through interest, learning, or capacity building). We contrast the benefits of acting and waiting in two ecosystems where restoration can mitigate forest bird extinction debts: South Australia’s Mount Lofty Ranges and Paraguay’s Atlantic Forest. In both cases, conservation outcomes cannot be maximized by front-loading spending, and the optimal solution recommends substantial delays before managers undertake conservation actions. Surprisingly, these delays allow superior conservation benefits to be achieved, in less time than front-loading. Our analyses provide an intuitive and mechanistic rationale for strategic delay, which contrasts with the orthodoxy of front-loaded spending for conservation actions. Our results illustrate the conservation efficiencies that could be achieved if decision makers choose when to spend their limited resources, as opposed to just where to spend them. PMID:28894004

Waiting can be an optimal conservation strategy, even in a crisis discipline.

PubMed

Iacona, Gwenllian D; Possingham, Hugh P; Bode, Michael

2017-09-26

Biodiversity conservation projects confront immediate and escalating threats with limited funding. Conservation theory suggests that the best response to the species extinction crisis is to spend money as soon as it becomes available, and this is often an explicit constraint placed on funding. We use a general dynamic model of a conservation landscape to show that this decision to "front-load" project spending can be suboptimal if a delay allows managers to use resources more strategically. Our model demonstrates the existence of temporal efficiencies in conservation management, which parallel the spatial efficiencies identified by systematic conservation planning. The optimal timing of decisions balances the rate of biodiversity decline (e.g., the relaxation of extinction debts, or the progress of climate change) against the rate at which spending appreciates in value (e.g., through interest, learning, or capacity building). We contrast the benefits of acting and waiting in two ecosystems where restoration can mitigate forest bird extinction debts: South Australia's Mount Lofty Ranges and Paraguay's Atlantic Forest. In both cases, conservation outcomes cannot be maximized by front-loading spending, and the optimal solution recommends substantial delays before managers undertake conservation actions. Surprisingly, these delays allow superior conservation benefits to be achieved, in less time than front-loading. Our analyses provide an intuitive and mechanistic rationale for strategic delay, which contrasts with the orthodoxy of front-loaded spending for conservation actions. Our results illustrate the conservation efficiencies that could be achieved if decision makers choose when to spend their limited resources, as opposed to just where to spend them.

A framework for evaluating capital structure.

PubMed

Sterns, J B; Majidzadeh, T K

1995-01-01

This article describes the rationale for accessing variable rate debt and the appropriate amount. It explores historical interest rate relationships and explains the motivation for incurring variable rate debt during certain interest rate environments. The article also explores the risks of variable rate debt and the liquid resources needed for prudent asset-liability management. Finally, the article outlines the financial statement impact of using variable rate debt.

40 CFR 13.34 - Purpose.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Purpose. 13.34 Section 13.34 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL CLAIMS COLLECTION STANDARDS Referral of Debts... Environmental Protection Agency (EPA) to refer past-due debts to the Internal Revenue Service (IRS) for offset...

Connectivity, non-random extinction and ecosystem function in experimental metacommunities.

PubMed

Staddon, Philip; Lindo, Zoë; Crittenden, Peter D; Gilbert, Francis; Gonzalez, Andrew

2010-05-01

The spatial insurance hypothesis indicates that connectivity is an important attribute of natural ecosystems that sustains both biodiversity and ecosystem function. We tested the hypothesis by measuring the impact of manipulating connectivity in experimental metacommunties of a natural and diverse microecosystem. Isolation led to the extinction of large-bodied apex predators, subsequently followed by increases in prey species abundance. This trophic cascade was associated with significantly altered carbon and nitrogen fluxes in fragmented treatments. The ecosystem impacts were characteristic of a function debt because they persisted for several generations after the initial loss of connectivity. Local extinctions and disruption of ecosystem processes were mitigated, and even reversed, by the presence of corridors in the connected metacommunities, although these beneficial effects were unexpectedly delayed. We hypothesized that corridors maintained grazer movement between fragments, which enhanced microbial activity, and decomposition in comparison to isolated fragments. Our results indicate that knowledge of habitat connectivity and spatial processes is essential to understand the magnitude and timing of ecosystem perturbation in fragmented landscapes.

Europe's other debt crisis caused by the long legacy of future extinctions.

PubMed

Dullinger, Stefan; Essl, Franz; Rabitsch, Wolfgang; Erb, Karl-Heinz; Gingrich, Simone; Haberl, Helmut; Hülber, Karl; Jarosík, Vojtech; Krausmann, Fridolin; Kühn, Ingolf; Pergl, Jan; Pysek, Petr; Hulme, Philip E

2013-04-30

Rapid economic development in the past century has translated into severe pressures on species survival as a result of increasing land-use change, environmental pollution, and the spread of invasive alien species. However, though the impact of these pressures on biodiversity is substantial, it could be seriously underestimated if population declines of plants and animals lag behind contemporary environmental degradation. Here, we test for such a delay in impact by relating numbers of threatened species appearing on national red lists to historical and contemporary levels of socioeconomic pressures. Across 22 European countries, the proportions of vascular plants, bryophytes, mammals, reptiles, dragonflies, and grasshoppers facing medium-to-high extinction risks are more closely matched to indicators of socioeconomic pressures (i.e., human population density, per capita gross domestic product, and a measure of land use intensity) from the early or mid-, rather than the late, 20th century. We conclude that, irrespective of recent conservation actions, large-scale risks to biodiversity lag considerably behind contemporary levels of socioeconomic pressures. The negative impact of human activities on current biodiversity will not become fully realized until several decades into the future. Mitigating extinction risks might be an even greater challenge if temporal delays mean many threatened species might already be destined toward extinction.

Europe’s other debt crisis caused by the long legacy of future extinctions

PubMed Central

Dullinger, Stefan; Essl, Franz; Rabitsch, Wolfgang; Erb, Karl-Heinz; Gingrich, Simone; Haberl, Helmut; Hülber, Karl; Jarošík, Vojtech; Krausmann, Fridolin; Kühn, Ingolf; Pergl, Jan; Pyšek, Petr; Hulme, Philip E.

2013-01-01

Rapid economic development in the past century has translated into severe pressures on species survival as a result of increasing land-use change, environmental pollution, and the spread of invasive alien species. However, though the impact of these pressures on biodiversity is substantial, it could be seriously underestimated if population declines of plants and animals lag behind contemporary environmental degradation. Here, we test for such a delay in impact by relating numbers of threatened species appearing on national red lists to historical and contemporary levels of socioeconomic pressures. Across 22 European countries, the proportions of vascular plants, bryophytes, mammals, reptiles, dragonflies, and grasshoppers facing medium-to-high extinction risks are more closely matched to indicators of socioeconomic pressures (i.e., human population density, per capita gross domestic product, and a measure of land use intensity) from the early or mid-, rather than the late, 20th century. We conclude that, irrespective of recent conservation actions, large-scale risks to biodiversity lag considerably behind contemporary levels of socioeconomic pressures. The negative impact of human activities on current biodiversity will not become fully realized until several decades into the future. Mitigating extinction risks might be an even greater challenge if temporal delays mean many threatened species might already be destined toward extinction. PMID:23589873

Environmental trends in extinction during the Paleozoic

NASA Technical Reports Server (NTRS)

Sepkoski, J. John, Jr.

1987-01-01

Extinction intensities calculated from 505 Paleozoic marine assemblages divided among six environmental zones and 40 stratigraphic intervals indicate that whole communities exhibit increasing extinction offshore but that genera within individual taxonomic classes tend to have their highest extinction onshore. The offshore trend at the community level results from a concentration of genera in classes with low characteristic extinction rates in nearshore environments. This finding is consistent with the ecologic expectation that organisms inhabiting unpredictably fluctuating environments should suffer more extinction than counterparts living under more predictably equitable conditions.

Ecological Catastrophes and Disturbance Relicts: A Case Study from Easter Island

NASA Astrophysics Data System (ADS)

Wynne, J.

2014-12-01

Caves are often considered buffered environments in terms of their ability to sustain near constant microclimatic conditions. However, environments within cave entrances are expected to respond most quickly to changing surface conditions. We cataloged a relict assemblage of at least 10 endemic arthropods likely restricted to caves and occurring primarily within cave entranceways. Of these animals, eight were considered new undescribed species. These endemic arthropods have persisted in Rapa Nui (Easter Island) caves despite a catastrophic ecological shift induced by island-wide deforestation, fire intolerance, and drought, as well as intensive livestock grazing and surface ecosystems dominated by invasive species. We consider these animals to be "disturbance relicts" - species whose distributions are now limited to areas that experienced minimal human disturbance historically. Today, these species represent one-third of the Rapa Nui's known endemic arthropods. Given the island's severely depauperate native fauna, these arthropods should be considered among the highest priority targets for biological conservation. In other regions globally, epigean examples of imperiled disturbance relicts persisting within narrow distributional ranges have been documented. As human activity intensifies, and habitat loss and fragmentation continues worldwide, additional disturbance relicts will be identified. We expect extinction debts, global climate change and interactions with invasive species will challenge the persistence of both hypogean and epigean disturbance relict species.

Sur la vitesse d'extinction d'une population dans un environnement aléatoire.

PubMed

Bacaër, Nicolas

2017-05-01

This study focuses on the speed of extinction of a population living in a random environment that follows a continuous-time Markov chain. Each individual dies or reproduces at a rate that depends on the environment. The number of offspring during reproduction follows a given probability law that also depends on the environment. In the so-called subcritical case where the population goes for sure to extinction, there is an explicit formula for the speed of extinction. In some sense, environmental stochasticity slows down population extinction. Copyright © 2017 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.

Debt swapping as a tool for economic and social stabilization in Russia's closed nuclear cities

DOE Office of Scientific and Technical Information (OSTI.GOV)

JL Fuller; KM Leek

2000-03-08

The magnitude of Russian foreign debt, both official bilateral and commercial, compounded by collapse of the Russian economic system, is an obstacle in preventing the Russian Federation from effectively increasing the domestic priority of drawing down its nuclear weapons complex and providing a healthy, competitive environment to its nuclear cities. Debt-for-nature swaps, introduced in the early 1980s, provide debtor nations with a means of converting a portion of foreign debt into local currency, often at steep discounts, to use for purposes such as environmental protection that serve both a domestic and international need. This paper presents the debt-for-nature concept asmore » a model for providing an infusion of funds to further U.S. and international nonproliferation objectives to help stabilize Russian closed city economic conditions through direct work on proliferation problems and remediation of the environment. A specific proposal is presented to demonstrate the utility and efficacy of the dept swap concept through initial collaboration with the city administration of Ozersk. The purpose of the proposal is to facilitate making Ozersk a safe, healthy competitive city, providing useful employment for its scientists and population and converting its superior infrastructure into productive activities.« less

Life history trade-off moderates model predictions of diversity loss from climate change.

PubMed

Moor, Helen

2017-01-01

Climate change can trigger species range shifts, local extinctions and changes in diversity. Species interactions and dispersal capacity are important mediators of community responses to climate change. The interaction between multispecies competition and variation in dispersal capacity has recently been shown to exacerbate the effects of climate change on diversity and to increase predictions of extinction risk dramatically. Dispersal capacity, however, is part of a species' overall ecological strategy and are likely to trade off with other aspects of its life history that influence population growth and persistence. In plants, a well-known example is the trade-off between seed mass and seed number. The presence of such a trade-off might buffer the diversity loss predicted by models with random but neutral (i.e. not impacting fitness otherwise) differences in dispersal capacity. Using a trait-based metacommunity model along a warming climatic gradient the effect of three different dispersal scenarios on model predictions of diversity change were compared. Adding random variation in species dispersal capacity caused extinctions by the introduction of strong fitness differences due an inherent property of the dispersal kernel. Simulations including a fitness-equalising trade-off based on empirical relationships between seed mass (here affecting dispersal distance, establishment probability, and seedling biomass) and seed number (fecundity) maintained higher initial species diversity and predicted lower extinction risk and diversity loss during climate change than simulations with variable dispersal capacity. Large seeded species persisted during climate change, but developed lags behind their climate niche that may cause extinction debts. Small seeded species were more extinction-prone during climate change but tracked their niches through dispersal and colonisation, despite competitive resistance from residents. Life history trade-offs involved in coexistence mechanisms may increase community resilience to future climate change and are useful guides for model development.

Debt and Graduation from American Universities

ERIC Educational Resources Information Center

Dwyer, Rachel E.; McCloud, Laura; Hodson, Randy

2012-01-01

The goal of "college-for-all" in the United States has been pursued in an environment of rising tuition, stagnant grant aid and already strapped family budgets with the gap filled by college loans. College students are thus facing increasing levels of debt as they seek to develop their human capital and improve their career options. Debt…

40 CFR 13.21 - Employee salary offset-general.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Employee salary offset-general. 13.21... STANDARDS Administrative Offset § 13.21 Employee salary offset—general. (a) Purpose. This section... collection by salary offset under 5 U.S.C. 5514 of debts owed EPA and debts owed to other Federal agencies by...

The context dependency of extinction negates the effectiveness of cognitive enhancement to reduce cocaine-primed reinstatement.

PubMed

Hammond, Sherri; Wagner, John J

2013-09-01

With respect to the treatment of addiction, the objective of extinction training is to decrease drug-seeking behavior by repeatedly exposing the patient to cues in the absence of unconditioned reinforcement. Such exposure therapy typically takes place in a novel (clinical) environment. This is potentially problematic, as the effects of extinction training include a context dependent component and therefore diminished efficacy is expected upon the patient's return to former drug-seeking/taking environments. We have reported that treatment with the NMDAR coagonist d-serine is effective in facilitating the effects of extinction to reduce cocaine-primed reinstatement. The present study assesses d-serine's effectiveness in reducing drug-primed reinstatement under conditions in which extinction training occurs in a novel environment. After 22 days of cocaine self-administration (0.5 mg/kg) in context "A", animals underwent 5 extinction training sessions in context "B". Immediately after each extinction session in "B", animals received either saline or d-serine (60 mg/kg) treatment. Our results indicate that d-serine treatment following extinction in "B" had no effect on either IV or IP cocaine-primed reinstatement conducted in "A". These results stand in contrast to our previous findings where extinction occurred in "A", indicating that d-serine's effectiveness in facilitating extinction training to reduce drug-primed reinstatement is not transferable to a novel extinction environment. This inability of d-serine treatment to reduce the context specificity of extinction training may explain the inconsistent effects observed in clinical studies published to date in which adjunctive cognitive enhancement treatment has been combined with behavioral therapy without significant benefit. Copyright © 2013 Elsevier B.V. All rights reserved.

A theoretical quantitative genetic study of negative ecological interactions and extinction times in changing environments.

PubMed

Jones, Adam G

2008-04-25

Rapid human-induced changes in the environment at local, regional and global scales appear to be contributing to population declines and extinctions, resulting in an unprecedented biodiversity crisis. Although in the short term populations can respond ecologically to environmental alterations, in the face of persistent change populations must evolve or become extinct. Existing models of evolution and extinction in changing environments focus only on single species, even though the dynamics of extinction almost certainly depend upon the nature of species interactions. Here, I use a model of quantitative trait evolution in a two-species community to show that negative ecological interactions, such as predation and competition, can produce unexpected results regarding time to extinction. Under some circumstances, negative interactions can be expected to hasten the extinction of species declining in numbers. However, under other circumstances, negative interactions can actually increase times to extinction. This effect occurs across a wide range of parameter values and can be substantial, in some cases allowing a population to persist for 40 percent longer than it would in the absence of the species interaction. This theoretical study indicates that negative species interactions can have unexpected positive effects on times to extinction. Consequently, detailed studies of selection and demographics will be necessary to predict the consequences of species interactions in changing environments for any particular ecological community.

Debt swapping as a tool for economic and social stabilization in Russia's closed nuclear cities (briefing paper)

DOE Office of Scientific and Technical Information (OSTI.GOV)

JL Fuller; KM Leek

2000-03-08

The next great issue on the Russian landscape will be management of its foreign debt. In the near future the United States will be called upon to lead an international program of debt restructuring to assist Russia in overcoming the burden of its debt trap. With debt service obligations equal to 50{percent} of 1999 revenues, Russia has virtually no chance of sustaining a program of economic recovery without debt relief (Hardt, 1999). With some form of debt restructuring a foregone conclusion, Russia, the United States, and world community have a vital stake in searching for creative ways to transform themore » inevitability of debt restructuring into something of value and constructive to Russia and the problems it faces. This was the rationale behind debt-for-nature swaps which emerged in the early 1980s in Latin American and Eastern Europe as a means of relieving developing nations of their crippling foreign debt. Debt-for-nature swaps served both domestic and international needs by converting a portion of foreign debt, often at steep discounts, into local currency that was then used to fund programs to preserve the environment. The debt swap mechanism provides the prospect of getting something of real value where nothing is expected. The Pacific Northwest National Laboratory (PNNL) has proposed to use the same model to synergistically capitalize defense threat reduction activities and environmental remediation within Russia's closed nuclear cities. Preventing the emigration of nuclear technology, expertise, and hardware from these cities to subnational groups and countries of proliferation concern is one of the world's foremost pressing problems. It is in the best national security interest of the United states to assist Russia in overcoming the legacy of the Cold War by helping to address the catastrophic environmental and public health effects of nuclear production that negatively impact economic stabilization.« less

More than a Question of Debt: A Qualitative Study of How Seminarians Think about Money

ERIC Educational Resources Information Center

Lincoln, Timothy D.

2015-01-01

As the funding environment for higher education and theological education changes, an increasing number of graduate theological students hold student loan debt that will follow them well into their postgraduation working lives (Delisle, 2014). This study reports the attitudes about money voiced by master of divinity students at one mainline…

Extinction of conditioned opiate withdrawal in rats is blocked by intracerebroventricular infusion of an NMDA receptor antagonist.

PubMed

Coleman, Brian R; Carlezon, William A; Myers, Karyn M

2013-04-29

Maladaptive conditioned responses (CRs) contribute to psychiatric disorders including anxiety disorders and addiction. Methods of reducing these CRs have been considered as possible therapeutic approaches. One such method is extinction, which involves exposure to CR-eliciting cues in the absence of the event they once predicted. In animal models, extinction reduces both fear and addiction-related CRs, and in humans, extinction-based cue exposure therapy (CET) reduces fear CRs. However, CET is less effective in drug addicts, for reasons that are not clear. Increased understanding of the neurobiology of extinction of drug-related CRs as compared to fear CRs may help illuminate this issue. Here, we examine the N-methyl-d-aspartate (NMDA) receptor-dependence of extinction of conditioned opiate withdrawal in rats. Using a place conditioning paradigm, we trained morphine-dependent rats to associate an environment with naloxone-precipitated withdrawal. We then extinguished that association by returning the rats repeatedly to the environment in the absence of acute withdrawal. In some rats we administered the NMDA receptor antagonist d,l-2-amino-5-phosphovaleric acid (AP5) intracerebroventricularly immediately prior to extinction training. In a subsequent test session, these rats avoided the formerly naloxone-paired environment, similar to rats that had not undergone extinction training. By contrast, rats that received vehicle prior to extinction training did not avoid the formerly naloxone-paired environment. This finding indicates that extinction of a drug-related CR (conditioned opiate withdrawal) is dependent on NMDA receptors, similar to extinction of conditioned fear. The locus of the critical NMDA receptors is unclear but may include basolateral amygdala and/or medial prefrontal cortex. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Extinction of conditioned opiate withdrawal in rats is blocked by intracerebroventricular infusion of an NMDA receptor antagonist

PubMed Central

Coleman, Brian R.; Carlezon, William A.; Myers, Karyn M.

2015-01-01

Maladaptive conditioned responses (CRs) contribute to psychiatric disorders including anxiety disorders and addiction. Methods of reducing these CRs have been considered as possible therapeutic approaches. One such method is extinction, which involves exposure to CR-eliciting cues in the absence of the event they once predicted. In animal models, extinction reduces both fear and addiction-related CRs, and in humans, extinction-based cue exposure therapy (CET) reduces fear CRs. However, CET is less effective in drug addicts, for reasons that are not clear. Increased understanding of the neurobiology of extinction of drug-related CRs as compared to fear CRs may help illuminate this issue. Here, we examine the N-methyl-D-aspartate (NMDA) receptor-dependence of extinction of conditioned opiate withdrawal in rats. Using a place conditioning paradigm, we trained morphine-dependent rats to associate an environment with naloxone-precipitated withdrawal. We then extinguished that association by returning the rats repeatedly to the environment in the absence of acute withdrawal. In some rats we administered the NMDA receptor antagonist D,L-2-amino-5-phosphovaleric acid (AP5) intracerebroventricularly immediately prior to extinction training. In a subsequent test session, these rats avoided the formerly naloxone-paired environment, similar to rats that had not undergone extinction training. By contrast, rats that received vehicle prior to extinction training did not avoid the formerly naloxone-paired environment. This finding indicates that extinction of a drug-related CR (conditioned opiate withdrawal) is dependent on NMDA receptors, similar to extinction of conditioned fear. The locus of the critical NMDA receptors is unclear but may include basolateral amygdala and/or medial prefrontal cortex. PMID:23416323

Metapopulation extinction risk: dispersal's duplicity.

PubMed

Higgins, Kevin

2009-09-01

Metapopulation extinction risk is the probability that all local populations are simultaneously extinct during a fixed time frame. Dispersal may reduce a metapopulation's extinction risk by raising its average per-capita growth rate. By contrast, dispersal may raise a metapopulation's extinction risk by reducing its average population density. Which effect prevails is controlled by habitat fragmentation. Dispersal in mildly fragmented habitat reduces a metapopulation's extinction risk by raising its average per-capita growth rate without causing any appreciable drop in its average population density. By contrast, dispersal in severely fragmented habitat raises a metapopulation's extinction risk because the rise in its average per-capita growth rate is more than offset by the decline in its average population density. The metapopulation model used here shows several other interesting phenomena. Dispersal in sufficiently fragmented habitat reduces a metapopulation's extinction risk to that of a constant environment. Dispersal between habitat fragments reduces a metapopulation's extinction risk insofar as local environments are asynchronous. Grouped dispersal raises the effective habitat fragmentation level. Dispersal search barriers raise metapopulation extinction risk. Nonuniform dispersal may reduce the effective fraction of suitable habitat fragments below the extinction threshold. Nonuniform dispersal may make demographic stochasticity a more potent metapopulation extinction force than environmental stochasticity.

Orexin/hypocretin is necessary for context-driven cocaine-seeking

PubMed Central

Smith, Rachel J.; Tahsili-Fahadan, Pouya; Aston-Jones, Gary

2009-01-01

Summary Orexin/hypocretin signaling at the orexin 1 receptor (OX1R) has recently been implicated in addiction and relapse. We examined the role of the orexin system in cocaine-seeking elicited by a drug-associated context following abstinence or extinction from chronic cocaine self-administration. Male Sprague-Dawley rats self-administered cocaine in 2-hour sessions for 10 days, followed by extinction training or extended abstinence in the home cage. The OX1R antagonist SB-334867 (SB; 10, 20, or 30 mg/kg, i.p.) was administered prior to re-exposure to the cocaine self-administration environment. We found that pretreatment with SB significantly attenuated cocaine-seeking when rats were placed back into the self-administration environment following either 1 day or 2 weeks of abstinence (no extinction), or following extinction of cocaine-seeking in an alternative environment (distinct from the training environment). These results indicate that orexin signaling at OX1R is critical for conditioned cocaine-seeking elicited by a drug-associated context, following either extinction or abstinence. PMID:19591850

Decreasing Your Student Loan Cohort Default Rate: Leading a College-Wide Change Initiative at Mohave Community College

ERIC Educational Resources Information Center

Charles, Kayla D.; Sheaff, Shannon; Woods, Jann; Downey, Lisa

2016-01-01

Burgeoning student debt and the ability of programs to adequately prepare students for jobs that will allow them to repay that debt comprise a topic of great interest in the current higher education policy environment. A key accountability measure used by the Department of Education for more than two decades has been the student loan cohort…

Persistence and extinction of a stochastic single-species model under regime switching in a polluted environment II.

PubMed

Liu, Meng; Wang, Ke

2010-12-07

This is a continuation of our paper [Liu, M., Wang, K., 2010. Persistence and extinction of a stochastic single-species model under regime switching in a polluted environment, J. Theor. Biol. 264, 934-944]. Taking both white noise and colored noise into account, a stochastic single-species model under regime switching in a polluted environment is studied. Sufficient conditions for extinction, stochastic nonpersistence in the mean, stochastic weak persistence and stochastic permanence are established. The threshold between stochastic weak persistence and extinction is obtained. The results show that a different type of noise has a different effect on the survival results. Copyright © 2010 Elsevier Ltd. All rights reserved.

Local population extinction and vitality of an epiphytic lichen in fragmented old-growth forest.

PubMed

Ockinger, Erik; Nilsson, Sven G

2010-07-01

The population dynamics of organisms living in short-lived habitats will largely depend on the turnover of habitat patches. It has been suggested that epiphytes, whose host plants can be regarded as habitat patches, often form such patch-tracking populations. However, very little is known about the long-term fate of epiphyte individuals and populations. We estimated life span and assessed environmental factors influencing changes in vitality, fertility, abundance, and distribution of the epiphytic lichen species Lobaria pulmonaria on two spatial scales, individual trees and forest patches, over a period of approximately 10 years in 66 old-growth forest fragments. The lichen had gone extinct from 7 of the 66 sites (13.0%) where it was found 10 years earlier, even though the sites remained unchanged. The risk of local population extinction increased with decreasing population size. In contrast to the decrease in the number of occupied trees and sites, the mean area of the lichen per tree increased by 43.0%. The number of trees with fertile ramets of L. pulmonaria increased from 7 (approximately 1%) to 61 (approximately 10%) trees, and the number of forest fragments with fertile ramets increased from 4 to 23 fragments. The mean annual rate of L. pulmonaria extinction at the tree level was estimated to be 2.52%, translating into an expected lifetime of 39.7 years. This disappearance rate is higher than estimated mortality rates for potential host trees. The risk of extinction at the tree level was significantly positively related to tree circumference and differed between tree species. The probability of presence of fertile ramets increased significantly with local population size. Our results show a long expected lifetime of Lobaria pulmonaria ramets on individual trees and a recent increase in vitality, probably due to decreasing air pollution. The population is, however, declining slowly even though remaining stands are left uncut, which we interpret as an extinction debt.

Life history trade-off moderates model predictions of diversity loss from climate change

PubMed Central

2017-01-01

Climate change can trigger species range shifts, local extinctions and changes in diversity. Species interactions and dispersal capacity are important mediators of community responses to climate change. The interaction between multispecies competition and variation in dispersal capacity has recently been shown to exacerbate the effects of climate change on diversity and to increase predictions of extinction risk dramatically. Dispersal capacity, however, is part of a species’ overall ecological strategy and are likely to trade off with other aspects of its life history that influence population growth and persistence. In plants, a well-known example is the trade-off between seed mass and seed number. The presence of such a trade-off might buffer the diversity loss predicted by models with random but neutral (i.e. not impacting fitness otherwise) differences in dispersal capacity. Using a trait-based metacommunity model along a warming climatic gradient the effect of three different dispersal scenarios on model predictions of diversity change were compared. Adding random variation in species dispersal capacity caused extinctions by the introduction of strong fitness differences due an inherent property of the dispersal kernel. Simulations including a fitness-equalising trade-off based on empirical relationships between seed mass (here affecting dispersal distance, establishment probability, and seedling biomass) and seed number (fecundity) maintained higher initial species diversity and predicted lower extinction risk and diversity loss during climate change than simulations with variable dispersal capacity. Large seeded species persisted during climate change, but developed lags behind their climate niche that may cause extinction debts. Small seeded species were more extinction-prone during climate change but tracked their niches through dispersal and colonisation, despite competitive resistance from residents. Life history trade-offs involved in coexistence mechanisms may increase community resilience to future climate change and are useful guides for model development. PMID:28520770

Extinction and the fossil record

NASA Technical Reports Server (NTRS)

Sepkoski, J. J. Jr; Sepkoski JJ, ,. J. r. (Principal Investigator)

1994-01-01

The author examines evidence of mass extinctions in the fossil record and searches for reasons for such large extinctions. Five major mass extinctions eliminated at least 40 percent of animal genera in the oceans and from 65 to 95 percent of ocean species. Questions include the occurrence of gradual or catastrophic extinctions, causes, environment, the capacity of a perturbation to cause extinctions each time it happens, and the possibility and identification of complex events leading to a mass extinction.

Persistence and extinction of an n-species mutualism model with random perturbations in a polluted environment

NASA Astrophysics Data System (ADS)

He, Xin; Shan, Meijing; Liu, Meng

2018-02-01

An n-species stochastic Lotka-Volterra cooperative model in a polluted environment is proposed and studied. For each species, sufficient conditions for extinction, non-persistence in the mean and weak persistence in the mean are established. The threshold between weak persistence in the mean and extinction is obtained. Several numerical figures are also worked out to validate the theoretical results.

[On the extinction of populations with several types in a random environment].

PubMed

Bacaër, Nicolas

2018-03-01

This study focuses on the extinction rate of a population that follows a continuous-time multi-type branching process in a random environment. Numerical computations in a particular example inspired by an epidemic model suggest an explicit formula for this extinction rate, but only for certain parameter values. Copyright © 2018 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.

Loss of dendritic connectivity in southern California's urban riverscape facilitates decline of an endemic freshwater fish

USGS Publications Warehouse

Richmond, Jonathan Q.; Backlin, Adam R.; Galst-Cavalcante, Carey; O'Brien, John W.; Fisher, Robert N.

2018-01-01

Life history adaptations and spatial configuration of metapopulation networks allow certain species to persist in extreme fluctuating environments, yet long-term stability within these systems relies on the maintenance of linkage habitat. Degradation of such linkages in urban riverscapes can disrupt this dynamic in aquatic species, leading to increased extinction debt in local populations experiencing environment-related demographic flux. We used microsatellites and mtDNA to examine the effects of collapsed network structure in the endemic Santa Ana sucker Catostomus santaanae of southern California, a threatened species affected by natural flood-drought cycles, ‘boom-and-bust’ demography, hybridization, and presumed artificial transplantation. Our results show a predominance of drift-mediated processes in shaping population structure, and that reverse mechanisms for counterbalancing the genetic effects of these phenomena have dissipated with the collapse of dendritic connectivity. We use approximate Bayesian models to support two cases of artificial transplantation, and provide evidence that one of the invaded systems better represents the historic processes that maintained genetic variation within watersheds than any remaining drainages where C. santaanae is considered native. We further show that a stable dry gap in the northern range is preventing genetic dilution of pure C. santaanae persisting upstream of a hybrid assemblage involving a non-native sucker, and that local accumulation of genetic variation in the same drainage is influenced by position within the network. This work has important implications for declining species that have historically relied on dendritic metapopulation networks to maintain source-sink dynamics in phasic environments, but no longer possess this capacity in urban-converted landscapes.

Rebuilding Biodiversity of Patagonian Marine Molluscs after the End-Cretaceous Mass Extinction

PubMed Central

Aberhan, Martin; Kiessling, Wolfgang

2014-01-01

We analysed field-collected quantitative data of benthic marine molluscs across the Cretaceous–Palaeogene boundary in Patagonia to identify patterns and processes of biodiversity reconstruction after the end-Cretaceous mass extinction. We contrast diversity dynamics from nearshore environments with those from offshore environments. In both settings, Early Palaeogene (Danian) assemblages are strongly dominated by surviving lineages, many of which changed their relative abundance from being rare before the extinction event to becoming the new dominant forms. Only a few of the species in the Danian assemblages were newly evolved. In offshore environments, however, two newly evolved Danian bivalve species attained ecological dominance by replacing two ecologically equivalent species that disappeared at the end of the Cretaceous. In both settings, the total number of Danian genera at a locality remained below the total number of late Cretaceous (Maastrichtian) genera at that locality. We suggest that biotic interactions, in particular incumbency effects, suppressed post-extinction diversity and prevented the compensation of diversity loss by originating and invading taxa. Contrary to the total number of genera at localities, diversity at the level of individual fossiliferous horizons before and after the boundary is indistinguishable in offshore environments. This indicates an evolutionary rapid rebound to pre-extinction values within less than ca 0.5 million years. In nearshore environments, by contrast, diversity of fossiliferous horizons was reduced in the Danian, and this lowered diversity lasted for the entire studied post-extinction interval. In this heterogeneous environment, low connectivity among populations may have retarded the recolonisation of nearshore habitats by survivors. PMID:25028930

Behavioral tagging of extinction learning.

PubMed

de Carvalho Myskiw, Jociane; Benetti, Fernando; Izquierdo, Iván

2013-01-15

Extinction of contextual fear in rats is enhanced by exposure to a novel environment at 1-2 h before or 1 h after extinction training. This effect is antagonized by administration of protein synthesis inhibitors anisomycin and rapamycin into the hippocampus, but not into the amygdala, immediately after either novelty or extinction training, as well as by the gene expression blocker 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole administered after novelty training, but not after extinction training. Thus, this effect can be attributed to a mechanism similar to synaptic tagging, through which long-term potentiation can be enhanced by other long-term potentiations or by exposure to a novel environment in a protein synthesis-dependent fashion. Extinction learning produces a tag at the appropriate synapses, whereas novelty learning causes the synthesis of plasticity-related proteins that are captured by the tag, strengthening the synapses that generated this tag.

Spondias tuberosa Arruda (Anacardiaceae), a threatened tree of the Brazilian Caatinga?

PubMed

Mertens, J; Germer, J; Siqueira, J A; Sauerborn, J

2017-01-01

Spondias tuberosa Arr., a fructiferous tree endemic to the northeast Brazilian tropical dry forest called Caatinga, accounts for numerous benefits for its ecosystem as well as for the dwellers of the Caatinga. The tree serves as feed for pollinators and dispersers as well as fodder for domestic ruminants, and is a source of additional income for local smallholders and their families. Despite its vantages, it is facing several man-made and natural threats, and it is suspected that S. tuberosa could become extinct. Literature review suggests that S. tuberosa suffers a reduced regeneration leading to population decrease. At this juncture S. tuberosa cannot be considered threatened according to the International Union for Conservation of Nature Red List Categories and Criteria, as it has not yet been assessed and hampered generative regeneration is not considered in the IUCN assessment. The combination of threats, however, may have already caused an extinction debt for S. tuberosa. Due to the observed decline in tree density, a thorough assessment of the S. tuberosa population is recommended, as well as a threat assessment throughout the entire Caatinga.

Mass extinctions in the deep sea

NASA Technical Reports Server (NTRS)

Thomas, E.

1988-01-01

The character of mass extinctions can be assessed by studying extinction patterns of organisms, the fabric of the extinction, and assessing the environmental niche and mode of life of survivors. Deep-sea benthic foraminifera have been listed as little affected by the Cretaceous-Tertiary (K-T) mass extinction, but very few quantitative data are available. New data on deep-sea Late Maestrichtian-Eocene benthic foraminifera from Maud Rise (Antractica) indicate that about 10 percent of the species living at depths of 2000 to 2500 m had last appearances within 1 my of the Cretaceous-Tertiary (K-T) boundary, versus about 25 percent of species at 1000 to 1500 m. Many survivors from the Cretaceous became extinct in a period of global deep-sea benthic foraminiferal extinction at the end of the Paleocene, a time otherwise marked by very few extinctions. Preliminary conclusions suggest that the deep oceanic environment is essentially decoupled from the shallow marine and terrestrial environment, and that even major disturbances of one of these will not greatly affect the other. This gives deep-sea benthic faunas a good opportunity to recolonize shallow environments from greater depths and vice versa after massive extinctions. The decoupling means that data on deep-sea benthic boundary was caused by the environmental effects of asteriod impact or excessive volcanism. The benthic foraminiferal data strongly suggest, however, that the environmental results were strongest at the Earth's surface, and that there was no major disturbance of the deep ocean; this pattern might result both from excessive volcanism and from an impact on land.

A Study of the Less-Developed-Countries Debt Crisis in Mexico and Subsequent Economic Policies

DTIC Science & Technology

2012-09-01

August, 1982, the Finance Minister of Mexico, Silvia Herzog informed the International Monetary Fund that Mexico was unable to meet its principle ...world. A principle cause of the 1983 debt crisis proved to be the ability of Mexico to borrow considerable sums of capital from the international...environment that is favorable to the accumulation of human knowledge.”30 Additionally, studies conducted by “Barro (1991), Mankiw , Romer, and Well (1992

Contextual-specificity of short-delay extinction in humans: Renewal of fear-potentiated startle in a virtual environment

PubMed Central

Alvarez, Ruben P.; Johnson, Linda; Grillon, Christian

2007-01-01

A recent fear-potentiated startle study in rodents suggested that extinction was not context dependent when extinction was conducted after a short delay following acquisition, suggesting that extinction can lead to erasure of fear learning in some circumstances. The main objective of this study was to attempt to replicate these findings in humans by examining the context specificity of short-delay extinction in an ABA renewal procedure using virtual reality environments. A second objective was to examine whether renewal, if any, would be influenced by context conditioning. Subjects underwent differential aversive conditioning in virtual context A, which was immediately followed by extinction in virtual context B. Extinction was followed by tests of renewal in context A and B, with the order counterbalanced across subjects. Results showed that extinction was context dependent. Evidence for renewal was established using fear-potentiated startle as well as skin conductance and fear ratings. In addition, although contextual anxiety was greater in the acquisition context than in the extinction context during renewal, as assessed with startle, context conditioning did not influence the renewal effect. These data do not support the view that extinction conducted shortly after acquisition is context independent. Hence, they do not provide evidence that extinction can lead to erasure of a fear memory established via Pavlovian conditioning. PMID:17412963

Amino acid racemization on Mars: implications for the preservation of biomolecules from an extinct martian biota

NASA Technical Reports Server (NTRS)

Bada, J. L.; McDonald, G. D.; Miller, S. L. (Principal Investigator)

1995-01-01

Using kinetic data, we have estimated the racemization half-lives and times for total racemization of amino acids under conditions relevant to the surface of Mars. Amino acids from an extinct martian biota maintained in a dry, cold (<250 K) environment would not have racemized significantly over the lifetime of the planet. Racemization would have taken place in environments where liquid water was present even for time periods of only a few million years following biotic extinction. The best preservation of both amino acid homochirality and nucleic acid genetic information associated with extinct martian life would be in the polar regions.

Methanol Droplet Extinction in Carbon-Dioxide-Enriched Environments in Microgravity

NASA Technical Reports Server (NTRS)

Hicks, Michael C.; Nayagam, Vedha; Williams, Forman A.

2010-01-01

Diffusive extinction of methanol droplets with initial diameters between 1.25 mm and 1.72 mm, burning in a quiescent microgravity environment at one atmosphere pressure, was obtained experimentally for varying levels of ambient carbon-dioxide concentrations with a fixed oxygen concentration of 21% and a balance of nitrogen. These experiments serve as precursors to those which are beginning to be performed on the International Space Station and are motivated by the need to understand the effectiveness of carbon-dioxide as a fire suppressant in low-gravity environments. In these experiments, the flame standoff distance, droplet diameter, and flame radiation are measured as functions of time. The results show that the droplet extinction diameter depends on both the initial droplet diameter and the ambient concentration of carbon dioxide. Increasing the initial droplet diameter leads to an increased extinction diameter, while increasing the carbon-dioxide concentration leads to a slight decrease in the extinction diameter. These results are interpreted using a critical Damk hler number for extinction as predicted by an earlier theory, which is extended here to be applicable in the presence of effects of heat conduction along the droplet support fibers and of the volume occupied by the support beads

The fossil record of evolution: Data on diversification and extinction

NASA Technical Reports Server (NTRS)

Sepkoski, J. J., Jr.

1991-01-01

Understanding of the evolution of complex life, and of the roles that changing terrestrial and extraterrestrial environments played in life's history, is dependent upon synthetic knowledge of the fossil record. Paleontologists have been describing fossils for more that two centuries. However, much of this information is dispersed in monographs and journal articles published throughout the world. Over the past several years, this literature was surveyed, and a data base on times of origination and extinction of fossil genera was compiled. The data base, which now holds approximately 32,000 genera, covers all taxonomic groups of marine animals, incorporates the most recent taxonomic assignments, and uses a detailed global time framework that can resolve originations and extinctions to intervals averaging three million years in duration. These data can be used to compile patterns of global biodiversity, measure rates of taxic evolution, and test hypotheses concerning adaptive radiations, mass extinctions, etc. Thus far, considerable effort was devoted to using the data to test the hypothesis of periodicity of mass extinction. Rates of extinction measured from the data base have also been used to calibrate models of evolutionary radiations in marine environments. It was observed that new groups, or clades of animals (i.e., orders and classes) tend to reach appreciable diversity first in nearshore environments and then to radiate in more offshore environments; during decline, these clades may disappear from the nearshore while persisting in offshore, deep water habitats. These observations have led to suggestions that there is something special about stressful or perturbed environments that promotes the evolution of novel kinds of animals that can rapidly replace their predecessors. The numerical model that is being investigated to study this phenomenon treats environments along onshore-offshore gradients as if they were discrete habitats. Other aspects of this investigation are presented.

Predicting evolutionary rescue via evolving plasticity in stochastic environments

PubMed Central

Baskett, Marissa L.

2016-01-01

Phenotypic plasticity and its evolution may help evolutionary rescue in a novel and stressful environment, especially if environmental novelty reveals cryptic genetic variation that enables the evolution of increased plasticity. However, the environmental stochasticity ubiquitous in natural systems may alter these predictions, because high plasticity may amplify phenotype–environment mismatches. Although previous studies have highlighted this potential detrimental effect of plasticity in stochastic environments, they have not investigated how it affects extinction risk in the context of evolutionary rescue and with evolving plasticity. We investigate this question here by integrating stochastic demography with quantitative genetic theory in a model with simultaneous change in the mean and predictability (temporal autocorrelation) of the environment. We develop an approximate prediction of long-term persistence under the new pattern of environmental fluctuations, and compare it with numerical simulations for short- and long-term extinction risk. We find that reduced predictability increases extinction risk and reduces persistence because it increases stochastic load during rescue. This understanding of how stochastic demography, phenotypic plasticity, and evolution interact when evolution acts on cryptic genetic variation revealed in a novel environment can inform expectations for invasions, extinctions, or the emergence of chemical resistance in pests. PMID:27655762

Contextual-Specificity of Short-Delay Extinction in Humans: Renewal of Fear-Potentiated Startle in a Virtual Environment

ERIC Educational Resources Information Center

Alvarez, Ruben P.; Johnson, Linda; Grillon, Christian

2007-01-01

A recent fear-potentiated startle study in rodents suggested that extinction was not context dependent when extinction was conducted after a short delay following acquisition, suggesting that extinction can lead to erasure of fear learning in some circumstances. The main objective of this study was to attempt to replicate these findings in humans…

40 CFR 30.37 - Property trust relationship.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 1 2011-07-01 2011-07-01 false Property trust relationship. 30.37 Section 30.37 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL... Property trust relationship. Real property, equipment, intangible property and debt instruments that are...

Environments and extinctions at the K-T boundary in eastern Montana are compatible with an asteroid impact

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fastovsky, D.E.; Sheehan, P.M.

1992-01-01

In the terrestrial latest Cretaceous Hell Creek (HC) Formation, both non-biotic events and patterns of extinction and survivorship are consistent with an asteroid impact causing the extinctions. Environments through the last 2--3 million-year interval represented by the HC remained relatively constant: an aggrading coastal lowland dissected by meandering rivers. The K-T boundary occurred during an abrupt change to impeded drainage represented by coals and pond deposits formed under low-energy conditions. Because of the close temporal proximity of the sediments of the Paleocene Cannonball Sea to the K-T boundary in South Dakota, impeded drainage in the earliest Paleocene in eastern Montanamore » may be attributable to riverine base-level changes associated with a renewed transgression of the western interior sea during the K-T transition. Patterns within the biota mirror those of the paleoenvironments. The ecological diversity of HC dinosaurs remains statistically unchanged through HC time. Analyses of vertebrates at the species level indicate a differential extinction in which the terrestrial biota underwent far more extinction than its aquatic counterpart. There is no evidence for changing environments in the upper HC, and there is circumstantial evidence that the latest Cretaceous was a time of renewed transgression rather than regression. Likewise, biotic patterns do not accord with gradual, environmentally driven extinctions. While the paleoenvironmental change that marks the K-T transition in eastern Montana accounts for some of the extinctions, the pattern of differential extinction is concordant with an asteroid impact. In this scenario, aquatic ecosystems and some land-based food chains would be buffered by detritus-based feeding. Terrestrial systems, dependent upon primary productivity, would undergo a short-term loss of resources causing extinctions.« less

Measurement of fog and haze extinction characteristics and availability evaluation of free space optical link under the sea surface environment.

PubMed

Wu, Xiaojun; Wang, Hongxing; Song, Bo

2015-02-10

Fog and haze can lead to changes in extinction characteristics. Therefore, the performance of the free space optical link is highly influenced by severe weather conditions. Considering the influential behavior of weather conditions, a state-of-the-art solution for the observation of fog and haze over the sea surface is presented in this paper. A Mie scattering laser radar, with a wavelength of 532 nm, is used to observe the weather conditions of the sea surface environment. The horizontal extinction coefficients and visibilities are obtained from the observation data, and the results are presented in the paper. The changes in the characteristics of extinction coefficients and visibilities are analyzed based on both the short-term (6 days) severe weather data and long-term (6 months) data. Finally, the availability performance of the free space optical communication link is evaluated under the sea surface environment.

Microbes and mass extinctions: paleoenvironmental distribution of microbialites during times of biotic crisis.

PubMed

Mata, S A; Bottjer, D J

2012-01-01

Widespread development of microbialites characterizes the substrate and ecological response during the aftermath of two of the 'big five' mass extinctions of the Phanerozoic. This study reviews the microbial response recorded by macroscopic microbial structures to these events to examine how extinction mechanism may be linked to the style of microbialite development. Two main styles of response are recognized: (i) the expansion of microbialites into environments not previously occupied during the pre-extinction interval and (ii) increases in microbialite abundance and attainment of ecological dominance within environments occupied prior to the extinction. The Late Devonian biotic crisis contributed toward the decimation of platform margin reef taxa and was followed by increases in microbialite abundance in Famennian and earliest Carboniferous platform interior, margin, and slope settings. The end-Permian event records the suppression of infaunal activity and an elimination of metazoan-dominated reefs. The aftermath of this mass extinction is characterized by the expansion of microbialites into new environments including offshore and nearshore ramp, platform interior, and slope settings. The mass extinctions at the end of the Triassic and Cretaceous have not yet been associated with a macroscopic microbial response, although one has been suggested for the end-Ordovician event. The case for microbialites behaving as 'disaster forms' in the aftermath of mass extinctions accurately describes the response following the Late Devonian and end-Permian events, and this may be because each is marked by the reduction of reef communities in addition to a suppression of bioturbation related to the development of shallow-water anoxia. © 2011 Blackwell Publishing Ltd.

A stochastic model for transmission, extinction and outbreak of Escherichia coli O157:H7 in cattle as affected by ambient temperature and cleaning practices.

PubMed

Wang, Xueying; Gautam, Raju; Pinedo, Pablo J; Allen, Linda J S; Ivanek, Renata

2014-08-01

Many infectious agents transmitting through a contaminated environment are able to persist in the environment depending on the temperature and sanitation determined rates of their replication and clearance, respectively. There is a need to elucidate the effect of these factors on the infection transmission dynamics in terms of infection outbreaks and extinction while accounting for the random nature of the process. Also, it is important to distinguish between the true and apparent extinction, where the former means pathogen extinction in both the host and the environment while the latter means extinction only in the host population. This study proposes a stochastic-differential equation model as an approximation to a Markov jump process model, using Escherichia coli O157:H7 in cattle as a model system. In the model, the host population infection dynamics are described using the standard susceptible-infected-susceptible framework, and the E. coli O157:H7 population in the environment is represented by an additional variable. The backward Kolmogorov equations that determine the probability distribution and the expectation of the first passage time are provided in a general setting. The outbreak and apparent extinction of infection are investigated by numerically solving the Kolmogorov equations for the probability density function of the associated process and the expectation of the associated stopping time. The results provide insight into E. coli O157:H7 transmission and apparent extinction, and suggest ways for controlling the spread of infection in a cattle herd. Specifically, this study highlights the importance of ambient temperature and sanitation, especially during summer.

THE MID-INFRARED EXTINCTION LAW AND ITS VARIATION IN THE COALSACK NEBULA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang Shu; Gao Jian; Jiang, B. W.

In recent years, the wavelength dependence of interstellar extinction from the ultraviolet (UV) to the near- and mid-infrared (IR) has been studied extensively. Although it is well established that the UV/optical extinction law varies significantly among the different lines of sight, it is not clear how IR extinction varies among various environments. In this work, using the color-excess method and taking red giants as the extinction tracer, we determine interstellar extinction A{sub {lambda}} in the four Spitzer/IRAC bands in [3.6], [4.5], [5.8], [8.0] {mu}m (relative to A{sub K{sub s}}, extinction in the Two Micron All Sky Survey (2MASS) K{sub s}more » band at 2.16 {mu}m) of the Coalsack nebula, a nearby starless dark cloud, based on the data obtained from the 2MASS and Spitzer/GLIMPSE surveys. We select five individual regions across the nebula that span a wide variety of physical conditions ranging from diffuse and translucent to dense environments, as traced by the visual extinction, the Spitzer/MIPS 24 {mu}m emission, and CO emission. We find that A{sub {lambda}}/A{sub K{sub s}}, mid-IR extinction relative to A{sub K{sub s}}, decreases from diffuse to dense environments, which may be explained in terms of ineffective dust growth in dense regions. The mean extinction (relative to A{sub K{sub s}}) is calculated for the four IRAC bands as well and exhibits a flat mid-IR extinction law consistent with previous determinations for other regions. Extinction in the IRAC 4.5 {mu}m band is anomalously high, much higher than that of the other three IRAC bands, and cannot be explained in terms of CO and CO{sub 2} ice. Mid-IR extinction in the four IRAC bands has also been derived for four representative regions in the Coalsack Globule 2, which respectively exhibit strong ice absorption, moderate or weak ice absorption, and very weak or no ice absorption. The derived mid-IR extinction curves are all flat, with A{sub {lambda}}/A{sub K{sub s}} increasing with the decrease of the 3.1 {mu}m H{sub 2}O ice absorption optical depth {tau}{sub ice}.« less

Role of hippocampal β-adrenergic and glucocorticoid receptors in the novelty-induced enhancement of fear extinction.

PubMed

Liu, Jian-Feng; Yang, Chang; Deng, Jia-Hui; Yan, Wei; Wang, Hui-Min; Luo, Yi-Xiao; Shi, Hai-Shui; Meng, Shi-Qiu; Chai, Bai-Sheng; Fang, Qin; Chai, Ning; Xue, Yan-Xue; Sun, Jia; Chen, Chen; Wang, Xue-Yi; Wang, Ji-Shi; Lu, Lin

2015-05-27

Fear extinction forms a new memory but does not erase the original fear memory. Exposure to novelty facilitates transfer of short-term extinction memory to long-lasting memory. However, the underlying cellular and molecular mechanisms are still unclear. Using a classical contextual fear-conditioning model, we investigated the effect of novelty on long-lasting extinction memory in rats. We found that exposure to a novel environment but not familiar environment 1 h before or after extinction enhanced extinction long-term memory (LTM) and reduced fear reinstatement. However, exploring novelty 6 h before or after extinction had no such effect. Infusion of the β-adrenergic receptor (βAR) inhibitor propranolol and glucocorticoid receptor (GR) inhibitor RU486 into the CA1 area of the dorsal hippocampus before novelty exposure blocked the effect of novelty on extinction memory. Propranolol prevented activation of the hippocampal PKA-CREB pathway, and RU486 prevented activation of the hippocampal extracellular signal-regulated kinase 1/2 (Erk1/2)-CREB pathway induced by novelty exposure. These results indicate that the hippocampal βAR-PKA-CREB and GR-Erk1/2-CREB pathways mediate the extinction-enhancing effect of novelty exposure. Infusion of RU486 or the Erk1/2 inhibitor U0126, but not propranolol or the PKA inhibitor Rp-cAMPS, into the CA1 before extinction disrupted the formation of extinction LTM, suggesting that hippocampal GR and Erk1/2 but not βAR or PKA play critical roles in this process. These results indicate that novelty promotes extinction memory via hippocampal βAR- and GR-dependent pathways, and Erk1/2 may serve as a behavioral tag of extinction. Copyright © 2015 the authors 0270-6474/15/358308-14$15.00/0.

Loss of dendritic connectivity in southern California's urban riverscape facilitates decline of an endemic freshwater fish.

PubMed

Richmond, Jonathan Q; Backlin, Adam R; Galst-Cavalcante, Carey; O'Brien, John W; Fisher, Robert N

2018-01-01

Life history adaptations and spatial configuration of metapopulation networks allow certain species to persist in extreme fluctuating environments, yet long-term stability within these systems relies on the maintenance of linkage habitat. Degradation of such linkages in urban riverscapes can disrupt this dynamic in aquatic species, leading to increased extinction debt in local populations experiencing environment-related demographic flux. We used microsatellites and mtDNA to examine the effects of collapsed network structure in the endemic Santa Ana sucker Catostomus santaanae of southern California, a threatened species affected by natural flood-drought cycles, "boom-and-bust" demography, hybridization and presumed artificial transplantation. Our results show a predominance of drift-mediated processes in shaping population structure and that reverse mechanisms for counterbalancing the genetic effects of these phenomena have dissipated with the collapse of dendritic connectivity. We use approximate Bayesian models to support two cases of artificial transplantation and provide evidence that one of the invaded systems better represents the historic processes that maintained genetic variation within watersheds than any remaining drainages where C. santaanae is considered native. We further show that a stable dry gap in the northern range is preventing genetic dilution of pure C. santaanae persisting upstream of a hybrid assemblage involving a non-native sucker and that local accumulation of genetic variation in the same drainage is influenced by position within the network. This work has important implications for declining species that have historically relied on dendritic metapopulation networks to maintain source-sink dynamics in phasic environments, but no longer possess this capacity in urban-converted landscapes. © 2017 John Wiley & Sons Ltd.

EXTINCTION LAWS TOWARD STELLAR SOURCES WITHIN A DUSTY CIRCUMSTELLAR MEDIUM AND IMPLICATIONS FOR TYPE IA SUPERNOVAE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nagao, Takashi; Maeda, Keiichi; Nozawa, Takaya, E-mail: nagao@kusastro.kyoto-u.ac.jp

Many astronomical objects are surrounded by dusty environments. In such dusty objects, multiple scattering processes of photons by circumstellar (CS) dust grains can effectively alter extinction properties. In this paper, we systematically investigate the effects of multiple scattering on extinction laws for steady-emission sources surrounded by the dusty CS medium using a radiation transfer simulation based on the Monte Carlo technique. In particular, we focus on whether and how the extinction properties are affected by properties of CS dust grains by adopting various dust grain models. We confirm that behaviors of the (effective) extinction laws are highly dependent on themore » properties of CS grains, especially the total-to-selective extinction ratio R{sub V}, which characterizes the extinction law and can be either increased or decreased and compared with the case without multiple scattering. We find that the criterion for this behavior is given by a ratio of albedos in the B and V bands. We also find that either small silicate grains or polycyclic aromatic hydrocarbons are necessary for realizing a low value of R{sub V} as often measured toward SNe Ia if the multiple scattering by CS dust is responsible for their non-standard extinction laws. Using the derived relations between the properties of dust grains and the resulting effective extinction laws, we propose that the extinction laws toward dusty objects could be used to constrain the properties of dust grains in CS environments.« less

Confounding environmental colour and distribution shape leads to underestimation of population extinction risk.

PubMed

Fowler, Mike S; Ruokolainen, Lasse

2013-01-01

The colour of environmental variability influences the size of population fluctuations when filtered through density dependent dynamics, driving extinction risk through dynamical resonance. Slow fluctuations (low frequencies) dominate in red environments, rapid fluctuations (high frequencies) in blue environments and white environments are purely random (no frequencies dominate). Two methods are commonly employed to generate the coloured spatial and/or temporal stochastic (environmental) series used in combination with population (dynamical feedback) models: autoregressive [AR(1)] and sinusoidal (1/f) models. We show that changing environmental colour from white to red with 1/f models, and from white to red or blue with AR(1) models, generates coloured environmental series that are not normally distributed at finite time-scales, potentially confounding comparison with normally distributed white noise models. Increasing variability of sample Skewness and Kurtosis and decreasing mean Kurtosis of these series alter the frequency distribution shape of the realised values of the coloured stochastic processes. These changes in distribution shape alter patterns in the probability of single and series of extreme conditions. We show that the reduced extinction risk for undercompensating (slow growing) populations in red environments previously predicted with traditional 1/f methods is an artefact of changes in the distribution shapes of the environmental series. This is demonstrated by comparison with coloured series controlled to be normally distributed using spectral mimicry. Changes in the distribution shape that arise using traditional methods lead to underestimation of extinction risk in normally distributed, red 1/f environments. AR(1) methods also underestimate extinction risks in traditionally generated red environments. This work synthesises previous results and provides further insight into the processes driving extinction risk in model populations. We must let the characteristics of known natural environmental covariates (e.g., colour and distribution shape) guide us in our choice of how to best model the impact of coloured environmental variation on population dynamics.

Predicting extinctions as a result of climate change

Treesearch

Mark W. Schwartz; Louis R. Iverson; Anantha M. Prasad; Stephen N. Matthews; Raymond J. O' Connor; Raymond J. O' Connor

2006-01-01

Widespread extinction is a predicted ecological consequence of global warming. Extinction risk under climate change scenarios is a function of distribution breadth. Focusing on trees and birds of the eastern United States, we used joint climate and environment models to examine fit and climate change vulnerability as a function of distribution breadth. We found that...

Persistence and extinction of a stochastic single-specie model under regime switching in a polluted environment.

PubMed

Liu, Meng; Wang, Ke

2010-06-07

A new single-species model disturbed by both white noise and colored noise in a polluted environment is developed and analyzed. Sufficient criteria for extinction, stochastic nonpersistence in the mean, stochastic weak persistence in the mean, stochastic strong persistence in the mean and stochastic permanence of the species are established. The threshold between stochastic weak persistence in the mean and extinction is obtained. The results show that both white and colored environmental noises have sufficient effect to the survival results. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Extinction of Contextual Fear with Timed Exposure to Enriched Environment: A Differential Effect

PubMed Central

Hegde, Preethi; O'Mara, Shane; Laxmi, Thenkanidiyoor Rao

2017-01-01

Background Extinction of fear memory depends on the environmental and emotional cues. Furthermore, consolidation of extinction is also dependent on the environmental exposure. But, the relationship of the time of the exposure to a variety of environmental cues is not well known. The important region involved in facilitation of extinction of fear memory is through diversion of the flow of information leaving the lateral nucleus of amygdala. Purpose The study aimed to address a question to explain how these brain regions react to environmental stimulation during the retention and extinction of fear memory. Methods An enriched environment (EE) is assumed to mediate extinction of fear memory, we examined the apparent discrepancy between the effects of defensive response, the freezing behavior induced by Pavlovian classical fear conditioning by subjecting them to variance in the timing to EE. The different timing of EE exposure was 10 days of EE either before fear conditioning and/or after extinction training to the rats. The local field potentials was recorded from CA1 hippocampus, lateral nucleus of amygdala and infralimbic region of medial prefrontal cortex (mPFC) during the fear learning and extinction from the control rats and rats exposed to EE before and after fear conditioning. Results Exposure to EE before the fear conditioning and after extinction training was more effective in the extinction fear memory. In addition, we also found switching from exploratory locomotion to freezing during retention of contextual fear memory which was associated with decreased theta power and reduced synchronized theta oscillations in CA1-hippocampus, lateral nucleus of amygdala, and infralimbic region of mPFC. Conclusion Thus, we propose that the timing of exposure to EE play a key role in the extinction of fear memory. PMID:28588364

Early life programming of fear conditioning and extinction in adult male rats.

PubMed

Stevenson, Carl W; Spicer, Clare H; Mason, Rob; Marsden, Charles A

2009-12-28

The early rearing environment programs corticolimbic function and neuroendocrine stress reactivity in adulthood. Although early environmental programming of innate fear has been previously examined, its impact on fear learning and memory later in life remains poorly understood. Here we examined the role of the early rearing environment in programming fear conditioning and extinction in adult male rats. Pups were subjected to maternal separation (MS; 360 min), brief handling (H; 15 min), or animal facility rearing (AFR) on post-natal days 2-14. As adults, animals were tested in a 3-day fear learning and memory paradigm which assessed the acquisition, expression and extinction of fear conditioning to an auditory cue; the recall of extinction was also assessed. In addition, contextual fear was assessed prior to cued extinction and its recall. We found that the acquisition of fear conditioning to the cue was modestly impaired by MS. However, no early rearing group differences were observed in cue-induced fear expression. In contrast, both the rate of extinction and extinction recall were attenuated by H. Finally, although contextual fear was reduced after extinction to the cue, no differences in context-induced fear were observed between the early rearing groups. These results add to a growing body of evidence supporting an important role for early environmental programming of fear conditioning and extinction. They also indicate that different early rearing conditions can program varying effects on distinct fear learning and memory processes in adulthood.

Dynamics of Droplet Extinction in Slow Convective Flows

NASA Technical Reports Server (NTRS)

Nayagam, V.; Haggard, J. B., Jr.; Williams, F. A.

1999-01-01

The classical model for droplet combustion predicts that the square of the droplet diameter decreases linearly with time. It also predicts that a droplet of any size will burn to completion over a period of time. However, it has been known for some time that under certain conditions flames surrounding a droplet, in a quiescent environment, could extinguish because of insufficient residence time for the chemistry to proceed to completion. This type of extinction that occurs for smaller droplets has been studied extensively in the past. Large droplets, on the other hand, exhibit a different type of extinction where excessive radiative heat loss from the flame zone leads to extinction. This mode of "radiative extinction" was theoretically predicted for droplet burning by Chao et al. and was observed in recent space experiments in a quiescent environment. Thus far, the fundamental flammability limit prescribed by radiative extinction of liquid droplets has been measured only under quiescent environmental conditions. In many space platforms, however, ventilation systems produce small convective flows and understanding of the influences of this convection on the extinction process will help better define the radiative extinction flammability boundaries. Boundaries defined by experiments and captured using theoretical models could provide enhanced fire safety margin in space explor1999063d investigation of convective effects will help in interpretations of burning-rate data obtained during free-floated droplet combustion experiments with small residual velocities.

Impaired extinction of fear conditioning after REM deprivation is magnified by rearing in an enriched environment.

PubMed

Hunter, Amy Silvestri

2015-07-01

Evidence from both human and animal studies indicates that rapid eye movement sleep (REM) is essential for the acquisition and retention of information, particularly of an emotional nature. Learning and memory can also be impacted by manipulation of housing condition such as exposure to an enriched environment (EE). This study investigated the effects of REM deprivation and EE, both separately and combined, on the extinction of conditioned fear in rats. Consistent with prior studies, conditioning was enhanced in EE-reared rats and extinction was impaired in REM deprived rats. In addition, rats exposed to both REM deprivation and EE showed the greatest impairment in extinction, with effects persisting through the first two days of extinction training. This study is the first to explore the combination of REM deprivation and EE and suggests that manipulations that alter sleep, particularly REM, can have persisting deleterious effects on emotional memory processing. Copyright © 2015 Elsevier Inc. All rights reserved.

Evolution of opercle shape in cichlid fishes from Lake Tanganyika - adaptive trait interactions in extant and extinct species flocks.

PubMed

Wilson, Laura A B; Colombo, Marco; Sánchez-Villagra, Marcelo R; Salzburger, Walter

2015-11-20

Phenotype-environment correlations and the evolution of trait interactions in adaptive radiations have been widely studied to gain insight into the dynamics underpinning rapid species diversification. In this study we explore the phenotype-environment correlation and evolution of operculum shape in cichlid fishes using an outline-based geometric morphometric approach combined with stable isotope indicators of macrohabitat and trophic niche. We then apply our method to a sample of extinct saurichthyid fishes, a highly diverse and near globally distributed group of actinopterygians occurring throughout the Triassic, to assess the utility of extant data to inform our understanding of ecomorphological evolution in extinct species flocks. A series of comparative methods were used to analyze shape data for 54 extant species of cichlids (N = 416), and 6 extinct species of saurichthyids (N = 44). Results provide evidence for a relationship between operculum shape and feeding ecology, a concentration in shape evolution towards present along with evidence for convergence in form, and significant correlation between the major axes of shape change and measures of gut length and body elongation. The operculum is one of few features that can be compared in extant and extinct groups, enabling reconstruction of phenotype-environment interactions and modes of evolutionary diversification in deep time.

Immediate Extinction Attenuates Spontaneous Recovery and Reinstatement in a Passive Avoidance Paradigm.

PubMed

Briggs, James F; Fava, Devin A

2016-08-01

Recent research suggests that extinction occurring shortly after fear conditioning attenuates spontaneous recovery and reinstatement of fear. Two experiments investigated whether immediate extinction would prevent spontaneous recovery and reinstatement of fear using a passive avoidance paradigm. In Experiment 1, naive female adult rats (N = 40) received extinction training either immediately or 24 hours (delayed) after fear conditioning. Both extinction groups showed a significant reduction in fear at a 1-day test. At a 15-day test, spontaneous recovery was observed in the delayed extinction group while the immediate extinction group continued to show significant extinction. In Experiment 2, using a naive group of adult female rats (N = 16), the extinction result was replicated in both the immediate and delayed extinction groups at the 1-day interval. Reinstatement of fear, elicited by foot-shock in a neutral environment, was observed for the delayed group but not for the immediate group. By utilizing the passive-avoidance paradigm, these experiments replicate and extend previous findings that immediate extinction attenuates spontaneous recovery and reinstatement of fear. © The Author(s) 2016.

Novel climates reverse carbon uptake of atmospherically dependent epiphytes: Climatic constraints on the iconic boreal forest lichen Evernia mesomorpha.

PubMed

Smith, Robert J; Nelson, Peter R; Jovan, Sarah; Hanson, Paul J; McCune, Bruce

2018-02-01

Changing climates are expected to affect the abundance and distribution of global vegetation, especially plants and lichens with an epiphytic lifestyle and direct exposure to atmospheric variation. The study of epiphytes could improve understanding of biological responses to climatic changes, but only if the conditions that elicit physiological performance changes are clearly defined. We evaluated individual growth performance of the epiphytic lichen Evernia mesomorpha, an iconic boreal forest indicator species, in the first year of a decade-long experiment featuring whole-ecosystem warming and drying. Field experimental enclosures were located near the southern edge of the species' range. Mean annual biomass growth of Evernia significantly declined 6 percentage points for every +1°C of experimental warming after accounting for interactions with atmospheric drying. Mean annual biomass growth was 14% in ambient treatments, 2% in unheated control treatments, and -9% to -19% (decreases) in energy-added treatments ranging from +2.25 to +9.00°C above ambient temperatures. Warming-induced biomass losses among persistent individuals were suggestive evidence of an extinction debt that could precede further local mortality events. Changing patterns of warming and drying would decrease or reverse Evernia growth at its southern range margins, with potential consequences for the maintenance of local and regional populations. Negative carbon balances among persisting individuals could physiologically commit these epiphytes to local extinction. Our findings illuminate the processes underlying local extinctions of epiphytes and suggest broader consequences for range shrinkage if dispersal and recruitment rates cannot keep pace. © 2018 Botanical Society of America.

Novel climates reverse carbon uptake of atmospherically dependent epiphytes: Climatic constraints on the iconic boreal forest lichen Evernia mesomorpha

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Robert J.; Nelson, Peter R.; Jovan, Sarah

Premise of the Study: Changing climates are expected to affect the abundance and distribution of global vegetation, especially plants and lichens with an epiphytic lifestyle and direct exposure to atmospheric variation. The study of epiphytes could improve understanding of biological responses to climatic changes, but only if the conditions that elicit physiological performance changes are clearly defined.Methods: We evaluated individual growth performance of the epiphytic lichen Evernia mesomorpha, an iconic boreal forest indicator species, in the first year of a decade-long experiment featuring whole-ecosystem warming and drying. Field experimental enclosures were located near the southern edge of the species’ range.Keymore » Results: Mean annual biomass growth of Evernia significantly declined 6 percentage points for every +1°C of experimental warming after accounting for interactions with atmospheric drying. Mean annual biomass growth was 14% in ambient treatments, 2% in unheated control treatments, and -9% to -19% (decreases) in energy-added treatments ranging from +2.25 to +9.00°C above ambient temperatures. Warming-induced biomass losses among persistent individuals were suggestive evidence of an extinction debt that could precede further local mortality events.Conclusions: Changing patterns of warming and drying would decrease or reverse Evernia growth at its southern range margins, with potential consequences for the maintenance of local and regional populations. Negative carbon balances among persisting individuals could physiologically commit these epiphytes to local extinction. Our findings illuminate the processes underlying local extinctions of epiphytes and suggest broader consequences for range shrinkage if dispersal and recruitment rates cannot keep pace.« less

Extinction hazards in experimental Daphnia magna populations: effects of genotype diversity and environmental variation

PubMed Central

Robinson, John D; Wares, John P; Drake, John M

2013-01-01

Extinction is ubiquitous in natural systems and the ultimate fate of all biological populations. However, the factors that contribute to population extinction are still poorly understood, particularly genetic diversity and composition. A laboratory experiment was conducted to examine the influences of environmental variation and genotype diversity on persistence in experimental Daphnia magna populations. Populations were initiated in two blocks with one, two, three, or six randomly selected and equally represented genotypes, fed and checked for extinction daily, and censused twice weekly over a period of 170 days. Our results show no evidence for an effect of the number of genotypes in a population on extinction hazard. Environmental variation had a strong effect on hazards in both experimental blocks, but the direction of the effect differed between blocks. In the first block, variable environments hastened extinction, while in the second block, hazards were reduced under variable food input. This occurred despite greater fluctuations in population size in variable environments in the second block of our experiment. Our results conflict with previous studies, where environmental variation consistently increased extinction risk. They are also at odds with previous studies in other systems that documented significant effects of genetic diversity on population persistence. We speculate that the lack of sexual reproduction, or the phenotypic similarity among our experimental lines, might underlie the lack of a significant effect of genotype diversity in our study. PMID:23467276

Species sorting and patch dynamics in harlequin metacommunities affect the relative importance of environment and space.

PubMed

Leibold, Mathew A; Loeuille, Nicolas

2015-12-01

Metacommunity theory indicates that variation in local community structure can be partitioned into components including those related to local environmental conditions vs. spatial effects and that these can be quantified using statistical methods based on variation partitioning. It has been hypothesized that joint associations of community composition with environment and space could be due to patch dynamics involving colonization-extinction processes in environmentally heterogeneous landscapes but this has yet to be theoretically shown. We develop a two-patch, type-two, species competition model in such a "harlequin" landscape (where different patches have different environments) to evaluate how composition is related to environmental and spatial effects as a function of background extinction rate. Using spatially implicit analytical models, we find that the environmental association of community composition declines with extinction rate as expected. Using spatially explicit simulation models, we further find that there is an increase in the spatial structure with extinction due to spatial patterning into clusters that are not related to environmental conditions but that this increase is limited. Natural metacommunities often show both environment and spatial determination even under conditions of relatively high isolation and these could be more easily explained by our model than alternative metacommunity models.

Asymmetric competition impacts evolutionary rescue in a changing environment.

PubMed

Van Den Elzen, Courtney L; Kleynhans, Elizabeth J; Otto, Sarah P

2017-06-28

Interspecific competition can strongly influence the evolutionary response of a species to a changing environment, impacting the chance that the species survives or goes extinct. Previous work has shown that when two species compete for a temporally shifting resource distribution, the species lagging behind the resource peak is the first to go extinct due to competitive exclusion. However, this work assumed symmetrically distributed resources and competition. Asymmetries can generate differences between species in population sizes, genetic variation and trait means. We show that asymmetric resource availability or competition can facilitate coexistence and even occasionally cause the leading species to go extinct first. Surprisingly, we also find cases where traits evolve in the opposite direction to the changing environment because of a 'vacuum of competitive release' created when the lagging species declines in number. Thus, the species exhibiting the slowest rate of trait evolution is not always the most likely to go extinct in a changing environment. Our results demonstrate that the extent to which species appear to be tracking environmental change and the extent to which they are preadapted to that change may not necessarily determine which species will be the winners and which will be the losers in a rapidly changing world. © 2017 The Author(s).

Facilitation of fear extinction by novelty depends on dopamine acting on D1-subtype dopamine receptors in hippocampus

PubMed Central

Menezes, Jefferson; Alves, Niége; Borges, Sidnei; Roehrs, Rafael; de Carvalho Myskiw, Jociane; Furini, Cristiane Regina Guerino; Izquierdo, Ivan; Mello-Carpes, Pâmela B.

2015-01-01

Extinction is the learned inhibition of retrieval. Recently it was shown that a brief exposure to a novel environment enhances the extinction of contextual fear in rats, an effect explainable by a synaptic tagging-and-capture process. Here we examine whether this also happens with the extinction of another fear-motivated task, inhibitory avoidance (IA), and whether it depends on dopamine acting on D1 or D5 receptors. Rats were trained first in IA and then in extinction of this task. The retention of extinction was measured 24 h later. A 5-min exposure to a novel environment 30 min before extinction training enhanced its retention. Right after exposure to the novelty, animals were given bilateral intrahippocampal infusions of vehicle (VEH), of the protein synthesis inhibitor anisomycin, of the D1/D5 dopaminergic antagonist SCH23390, of the PKA inhibitor Rp-cAMP or of the PKC inhibitor Gö6976, and of the PKA stimulator Sp-cAMP or of the PKC stimulator PMA. The novelty increased hippocampal dopamine levels and facilitated the extinction, which was inhibited by intrahippocampal protein synthesis inhibitor anisomysin, D1/D5 dopaminerdic antagonist SCH23390, or PKA inhibitor Rp-cAMP and unaffected by PKC inhibitor Gö6976; additionally, the hippocampal infusion of PKA stimulator Sp-cAMP reverts the effect of D1/D5 dopaminergic antagonist SCH 23390, but the infusion of PKC stimulator PMA does not. The results attest to the generality of the novelty effect on fear extinction, suggest that it relies on synaptic tagging and capture, and show that it depends on hippocampal dopamine D1 but not D5 receptors. PMID:25775606

Climate change risks, extinction debt, and conservation implications for a threatened freshwater fish: Carmine shiner (Notropis percobromus).

PubMed

Pandit, Shubha N; Maitland, Bryan M; Pandit, Laxmi K; Poesch, Mark S; Enders, Eva C

2017-11-15

Climate change is affecting many freshwater species, particularly fishes. Predictions of future climate change suggest large and deleterious effects on species with narrow dispersal abilities due to limited hydrological connectivity. In turn, this creates the potential for population isolation in thermally unsuitable habitats, leading to physiological stress, species declines or possible extirpation. The current extent of many freshwater fish species' spatio-temporal distribution patterns and their sensitivity to thermal impacts from climate change - critical information for conservation planning - are often unknown. Carmine shiner (Notropis percobromus) is an ecologically important species listed as threatened or imperilled nationally (Canada) and regionally (South Dakota, United States) due to its restricted range and sensitivity to water quality and temperature. This research aimed to determine the current distribution and spatio-temporal variability in projected suitable habitat for Carmine shiner using niche-based modeling approaches (MaxEnt, BIOCLIM, and DOMAIN models). Statistically downscaled, bias-corrected Global Circulation Models (GCMs) data was used to model the distribution of Carmine shiner in central North America for the period of 2041-2060 (2050s). Maximum mean July temperature and temperature variability were the main factors in determining Carmine shiner distribution. Patterns of projected habitat change by the 2050s suggest the spatial extent of the current distribution of Carmine shiner would shift north, with >50% of the current distribution changing with future projections based on two Representative Concentrations Pathways for CO 2 emissions. Whereas the southern extent of the distribution would become unsuitable for Carmine shiner, suitable habitats are predicted to become available further north, if accessible. Importantly, the majority of habitat gains for Carmine shiner would be in areas currently inaccessible due to dispersal limitations, suggesting current populations may face an extinction debt within the next half century. These results provide evidence that Carmine shiner may be highly vulnerable to a warming climate and suggest that management actions - such as assisted migration - may be needed to mitigate impacts from climate change and ensure the long-term persistence of the species. Copyright © 2017 Elsevier B.V. All rights reserved.

An experimental study of opposed flow diffusion flame extinction over a thin fuel in microgravity. M.S. Thesis. Final Report

NASA Technical Reports Server (NTRS)

Ferkul, Paul V.

1989-01-01

The flame spread and flame extinction characteristics of a thin fuel burning in a low-speed forced convective environment in microgravity were examined. The flame spread rate was observed to decrease both with decreasing ambient oxygen concentration as well as decreasing free stream velocity. A new mode of flame extinction was observed, caused by either of two means: keeping the free stream velocity constant and decreasing the oxygen concentration, or keeping the oxygen concentration constant and decreasing the free stream velocity. This extinction is called quenching extinction. By combining this data together with a previous microgravity quiescent flame study and normal-gravity blowoff extinction data, a flammability map was constructed with molar percentage oxygen and characteristic relative velocity as coordinates. The Damkohler number is not sufficient to predict flame spread and extinction in the near quench limit region.

Evolution Under Environmental Stress at Macro- and Microscales

PubMed Central

Nevo, Eviatar

2011-01-01

Environmental stress has played a major role in the evolution of living organisms (Hoffman AA, Parsons PA. 1991. Evolutionary genetics and environmental stress. Oxford: Oxford University Press; Parsons PA. 2005. Environments and evolution: interactions between stress, resource inadequacy, and energetic efficiency. Biol Rev Camb Philos Soc. 80:589–610). This is reflected by the massive and background extinctions in evolutionary time (Nevo E. 1995a. Evolution and extinction. Encyclopedia of Environmental Biology. New York: Academic Press, Inc. 1:717–745). The interaction between organism and environment is central in evolution. Extinction ensues when organisms fail to change and adapt to the constantly altering abiotic and biotic stressful environmental changes as documented in the fossil record. Extreme environmental stress causes extinction but also leads to evolutionary change and the origination of new species adapted to new environments. I will discuss a few of these global, regional, and local stresses based primarily on my own research programs. These examples will include the 1) global regional and local experiment of subterranean mammals; 2) regional experiment of fungal life in the Dead Sea; 3) evolution of wild cereals; 4) “Evolution Canyon”; 5) human brain evolution, and 6) global warming. PMID:21979157

Evolution under environmental stress at macro- and microscales.

PubMed

Nevo, Eviatar

2011-01-01

Environmental stress has played a major role in the evolution of living organisms (Hoffman AA, Parsons PA. 1991. Evolutionary genetics and environmental stress. Oxford: Oxford University Press; Parsons PA. 2005. Environments and evolution: interactions between stress, resource inadequacy, and energetic efficiency. Biol Rev Camb Philos Soc. 80:589-610). This is reflected by the massive and background extinctions in evolutionary time (Nevo E. 1995a. Evolution and extinction. Encyclopedia of Environmental Biology. New York: Academic Press, Inc. 1:717-745). The interaction between organism and environment is central in evolution. Extinction ensues when organisms fail to change and adapt to the constantly altering abiotic and biotic stressful environmental changes as documented in the fossil record. Extreme environmental stress causes extinction but also leads to evolutionary change and the origination of new species adapted to new environments. I will discuss a few of these global, regional, and local stresses based primarily on my own research programs. These examples will include the 1) global regional and local experiment of subterranean mammals; 2) regional experiment of fungal life in the Dead Sea; 3) evolution of wild cereals; 4) "Evolution Canyon"; 5) human brain evolution, and 6) global warming.

Coming to terms: toward a North-South bargain for the environment.

PubMed

Speth, J G

1989-06-01

To attack the major environmental problems, global warming, natural resource losses, and loss of biological diversity, an understanding between the industrialized and developing countries must occur. Weather patterns and sea levels are being affected by global warming which is caused by the use of fossil fuels and deforestation. The industrialized countries must cut back on the use of fossil fuels, and developing countries need to slow the process of deforestation. The loss of genetic resources and the extinction of species is happening rapidly, and most of it is in the tropical forests of developing countries. The developing countries are more dependent on their natural resources, forests, minerals, soils, and fisheries than industrialized countries. They are being depleted more rapidly with the population growth, social inequalities, and poor policies. Industrial countries are partly to blame also since they make investment and development decisions without concerns for the environment. The 4 major actions that can be initiated by industrialized countries are as follows. The initiation of national and international movements to reduce gas emissions that cause the greenhouse effect. The increased distribution of new technology and financing for population programs, sustainable development and environmental protection. The reduction of the external dept of developing countries, and the creation of programs to give technical assistance, scientific and other training for environmental problems of developing countries. Financial assistance can be linked to population programs and to environmental issues of the developing countries. Carbon dioxide taxes could be used to finance forest management and ecological zoning. The exchange of forest conservation for debt relief is a possible solution. Any dept restructuring plan should include strong environmental conservation provisions and policy reform requirements.

Range contraction enables harvesting to extinction.

PubMed

Burgess, Matthew G; Costello, Christopher; Fredston-Hermann, Alexa; Pinsky, Malin L; Gaines, Steven D; Tilman, David; Polasky, Stephen

2017-04-11

Economic incentives to harvest a species usually diminish as its abundance declines, because harvest costs increase. This prevents harvesting to extinction. A known exception can occur if consumer demand causes a declining species' harvest price to rise faster than costs. This threat may affect rare and valuable species, such as large land mammals, sturgeons, and bluefin tunas. We analyze a similar but underappreciated threat, which arises when the geographic area (range) occupied by a species contracts as its abundance declines. Range contractions maintain the local densities of declining populations, which facilitates harvesting to extinction by preventing abundance declines from causing harvest costs to rise. Factors causing such range contractions include schooling, herding, or flocking behaviors-which, ironically, can be predator-avoidance adaptations; patchy environments; habitat loss; and climate change. We use a simple model to identify combinations of range contractions and price increases capable of causing extinction from profitable overharvesting, and we compare these to an empirical review. We find that some aquatic species that school or forage in patchy environments experience sufficiently severe range contractions as they decline to allow profitable harvesting to extinction even with little or no price increase; and some high-value declining aquatic species experience severe price increases. For terrestrial species, the data needed to evaluate our theory are scarce, but available evidence suggests that extinction-enabling range contractions may be common among declining mammals and birds. Thus, factors causing range contraction as abundance declines may pose unexpectedly large extinction risks to harvested species.

Range contraction enables harvesting to extinction

PubMed Central

Burgess, Matthew G.; Costello, Christopher; Gaines, Steven D.; Tilman, David; Polasky, Stephen

2017-01-01

Economic incentives to harvest a species usually diminish as its abundance declines, because harvest costs increase. This prevents harvesting to extinction. A known exception can occur if consumer demand causes a declining species’ harvest price to rise faster than costs. This threat may affect rare and valuable species, such as large land mammals, sturgeons, and bluefin tunas. We analyze a similar but underappreciated threat, which arises when the geographic area (range) occupied by a species contracts as its abundance declines. Range contractions maintain the local densities of declining populations, which facilitates harvesting to extinction by preventing abundance declines from causing harvest costs to rise. Factors causing such range contractions include schooling, herding, or flocking behaviors—which, ironically, can be predator-avoidance adaptations; patchy environments; habitat loss; and climate change. We use a simple model to identify combinations of range contractions and price increases capable of causing extinction from profitable overharvesting, and we compare these to an empirical review. We find that some aquatic species that school or forage in patchy environments experience sufficiently severe range contractions as they decline to allow profitable harvesting to extinction even with little or no price increase; and some high-value declining aquatic species experience severe price increases. For terrestrial species, the data needed to evaluate our theory are scarce, but available evidence suggests that extinction-enabling range contractions may be common among declining mammals and birds. Thus, factors causing range contraction as abundance declines may pose unexpectedly large extinction risks to harvested species. PMID:28351981

Unexpected amino acid composition of modern Reptilia and its implications in molecular mechanisms of dinosaur extinction.

PubMed

Wang, Guang-Zhong; Ma, Bin-Guang; Yang, Yan; Zhang, Hong-Yu

2005-08-12

Dinosaur extinction is a great challenge to evolutionary biology. Although accumulating evidence suggests that an abrupt change of environment, such as a long period of low temperature induced by asteroid hit or other disasters, may be responsible for dinosaur extinction, little is known about the underlying molecular mechanisms. By analyzing the amino acid compositions of 13 biological classes, we found that the charged amino acid content of modern Reptilia, the sibling of dinosaur, is strikingly different from those of other classes, which inspires us to propose a possible molecular mechanism for dinosaur extinction.

The extinction context enables extinction performance after a change in context

PubMed Central

Nelson, James Byron; Gregory, Pamela; Sanjuan, Maria del Carmen

2012-01-01

One experiment with human participants determined the extent to which recovery of extinguished responding with a context switch was due to a failure to retrieve contextually-controlled learning, or some other process such as participants learning that context changes signal reversals in the meaning of stimulus – outcome relationships. In a video game, participants learned to suppress mouse clicking in the presence of a stimulus that predicted an attack. Then, that stimulus underwent extinction in a different context (environment within the game). Following extinction, suppression was recovered and then extinguished again during testing in the conditioning context. In a final test, participants that were tested in the context where extinction first took place showed less of a recovery than those tested in a neutral context, but they showed a recovery of suppression nevertheless. A change in context tended to cause a change in the meaning of the stimulus, leading to recovery in both the neutral and extinction contexts. The extinction context attenuated that recovery, perhaps by enabling retrieval of the learning that took place in extinction. Recovery outside an extinction context is due to a failure of the context to enable the learning acquired during extinction, but only in part. PMID:22521549

Forecasting extinction risk with nonstationary matrix models.

PubMed

Gotelli, Nicholas J; Ellison, Aaron M

2006-02-01

Matrix population growth models are standard tools for forecasting population change and for managing rare species, but they are less useful for predicting extinction risk in the face of changing environmental conditions. Deterministic models provide point estimates of lambda, the finite rate of increase, as well as measures of matrix sensitivity and elasticity. Stationary matrix models can be used to estimate extinction risk in a variable environment, but they assume that the matrix elements are randomly sampled from a stationary (i.e., non-changing) distribution. Here we outline a method for using nonstationary matrix models to construct realistic forecasts of population fluctuation in changing environments. Our method requires three pieces of data: (1) field estimates of transition matrix elements, (2) experimental data on the demographic responses of populations to altered environmental conditions, and (3) forecasting data on environmental drivers. These three pieces of data are combined to generate a series of sequential transition matrices that emulate a pattern of long-term change in environmental drivers. Realistic estimates of population persistence and extinction risk can be derived from stochastic permutations of such a model. We illustrate the steps of this analysis with data from two populations of Sarracenia purpurea growing in northern New England. Sarracenia purpurea is a perennial carnivorous plant that is potentially at risk of local extinction because of increased nitrogen deposition. Long-term monitoring records or models of environmental change can be used to generate time series of driver variables under different scenarios of changing environments. Both manipulative and natural experiments can be used to construct a linking function that describes how matrix parameters change as a function of the environmental driver. This synthetic modeling approach provides quantitative estimates of extinction probability that have an explicit mechanistic basis.

A general theory of impacts and mass extinctions, and the consequences of large-body impact on the Earth

NASA Technical Reports Server (NTRS)

Rampino, M. R.

1994-01-01

The theory that large-body impacts are the primary cause of mass extinctions of life on the Earth now has a sound theoretical and observational foundation. A convergence of evidence suggests that the biosphere may be a sensitive detector of large impact events, which result in the recorded global mass extinction pulses. The astronomically observed flux of asteroids and comets in the neighborhood of the Earth, and the threshold impact size calculated to produce a global environment catastrophe, can be used to predict a time history of large impact events and related mass extinctions of life that agrees well with the record of approx. 24 extinction events in the last 540 m.y.

Neogene reef coral assemblages of the Bocas del Toro region, Panama: the rise of Acropora palmata

NASA Astrophysics Data System (ADS)

Klaus, J. S.; McNeill, D. F.; Budd, A. F.; Coates, A. G.

2012-03-01

Temporal patterns are evaluated in Neogene reef coral assemblages from the Bocas del Toro Basin of Panama in order to understand how reef ecosystems respond to long-term environmental change. Analyses are based on a total of 1,702 zooxanthellate coral specimens collected from six coral-bearing units ranging in age from the earliest Late Miocene to the Early Pleistocene: (1) Valiente Formation (12-11 Ma), (2) Fish Hole Member of the Old Bank Formation (5.8-5.6 Ma), (3) La Gruta Member of the Isla Colon Formation (2.2-1.4 Ma), (4) Ground Creek Member of the Isla Colon Formation (2.2-1.4 Ma), (5) Mimitimbi Member of the Urracá Formation (1.2-0.8 Ma), and (6) Hill Point Member of the Urracá Formation (1.2-0.8 Ma). Over 100 coral species occur in the six units, with faunal assemblages ranging from less than 10% extant taxa (Valiente Formation) to over 85% extant taxa (Ground Creek Member). The collections provide new temporal constraints on the emergence of modern Caribbean reefs, with the La Gruta Member containing the earliest occurrence of large monospecific stands of the dominant Caribbean reef coral Acropora palmata, and the Urracá Formation containing the last fossil occurrences of 15 regionally extinct taxa. Canonical correspondence analysis of 41 Late Miocene to Recent reef coral assemblages from the Caribbean region suggests changes in community structure coincident with effective oceanic closure of the Central American Seaway (~3.5 Ma). These changes, including increased Acropora dominance, may have contributed to a protracted period of elevated extinction debt prior to the major peak in regional coral extinctions (~2-1 Ma).

5 CFR 835.602 - Past-due legally enforceable debt.

Code of Federal Regulations, 2010 CFR

2010-01-01

... REGULATIONS (CONTINUED) DEBT COLLECTION Collection of Debts by Federal Tax Refund Offset § 835.602 Past-due legally enforceable debt. A past-due legally enforceable debt for referral to the IRS is a debt that— (a... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Past-due legally enforceable debt. 835...

High Current Anxiety Symptoms, But Not a Past Anxiety Disorder Diagnosis, are Associated with Impaired Fear Extinction

PubMed Central

Duits, Puck; Cath, Danielle C.; Heitland, Ivo; Baas, Johanna M. P.

2016-01-01

Although impaired fear extinction has repeatedly been demonstrated in patients with anxiety disorders, little is known about whether these impairments persist after treatment. The current comparative exploratory study investigated fear extinction in 26 patients treated for their anxiety disorder in the years preceding the study as compared to 17 healthy control subjects. Fear-potentiated startle and subjective fear were measured in a cue and context fear conditioning paradigm within a virtual reality environment. Results indicated no differences in fear extinction between treated anxiety patients and control subjects. However, scores on the Beck Anxiety Inventory across all participants revealed impaired extinction of fear potentiated startle in subjects with high compared to low anxiety symptoms over the past week. Taken together, this exploratory study found no support for impaired fear extinction in treated anxiety patients, and implies that current anxiety symptoms rather than previous patient status determine the success of extinction. PMID:26955364

DEVELOPMENT OF AQUATIC MODELS FOR TESTING THE RELATIONSHIP BETWEEN GENETIC DIVERSITY AND POPULATION EXTINCTION RISK

EPA Science Inventory

The relationship between population adaptive potential and extinction risk in a changing environment is not well understood. Although the expectation is that genetic diversity is directly related to the capacity of populations to adapt, the statistical and predictive aspects of ...

Extinction Mapping and Dust-to-Gas Ratios of Nearby Galaxies using LEGUS

NASA Astrophysics Data System (ADS)

Kahre, Lauren; Walterbos, Rene; Kim, Hwihyun; Thilker, David; Lee, Janice; LEGUS Team

2018-01-01

Dust is commonly used as a tracer for cold dense gas, either through IR and NIR emission maps or through extinction mapping, and dust abundance and gas metallicity are critical constraints for chemical and galaxy evolution models. Extinction mapping has been used to trace dust column densities in the Milky Way, the Magellanic Clouds, and M31. The maps for M31 use IR and NIR photometry of red giant branch stars, which is more difficult to obtain for more distant galaxies. Work by Kahre et al. (in prep) uses the extinctions derived for individual massive stars using the isochrone-matching method described by Kim et al. (2012) to generate extinction maps for these more distant galaxies.Isochrones of massive stars lie in the same location on a color-color diagram with little dependence on metallicity and luminosity class, so the extinction can be directly derived from the observed photometry. We generate extinction maps using photometry of massive stars from the Hubble Space Telescope for several of the nearly 50 galaxies observed by the Legacy Extragalactic Ultraviolet Survey (LEGUS). The derived extinction maps will allow us to correct ground-based and HST Halpha maps for extinction, and will be used to constrain changes in the dust-to-gas ratio across the galaxy sample and in different star formation, metallicity and morphological environments. Previous studies have found links between galaxy metallicity and the dust-to-gas mass ratio. We present a study of LEGUS galaxies spanning a range of distances, metallicities, and galaxy morphologies, expanding on our previous study of metal-poor dwarfs Holmberg I and II and giant spirals NGC 6503 and NGC 628. We see clear evidence for changes in the dust-to-gas mass ratio with changing metallicity. We also examine changes in the dust-to-gas mass ratio with galactocentric radius. Ultimately, we will provide constraints on the dust-to-gas mass ratio across a wide range of galaxy environments.

Extinction Criteria for Opposed-Flow Flame Spread in a Microgravity Environment

NASA Technical Reports Server (NTRS)

Bhattacharjee, Subrata; Paolini, Chris; Wakai, Kazunori; Takahashi, Shuhei

2003-01-01

A simplified analysis is presented to extend a previous work on flame extinction in a quiescent microgravity environment to a more likely situation of a mild opposing flow. The energy balance equation, that includes surface re-radiation, is solved to yield a closed form spread rate expression in terms of its thermal limit, and a radiation number that can be evaluated from the known parameters of the problem. Based on this spread rate expression, extinction criterions for a flame over solid fuels, both thin and thick, have been developed that are qualitatively verified with experiments conducted at the MGLAB in Japan. Flammability maps with oxygen level, opposing flow velocity and fuel thickness as independent variables are extracted from the theory that explains the well-established trends in the existing experimental data.

Genetic disruptions of Drosophila Pavlovian learning leave extinction learning intact.

PubMed

Qin, H; Dubnau, J

2010-03-01

Individuals who experience traumatic events may develop persistent posttraumatic stress disorder. Patients with this disorder are commonly treated with exposure therapy, which has had limited long-term success. In experimental neurobiology, fear extinction is a model for exposure therapy. In this behavioral paradigm, animals are repeatedly exposed in a safe environment to the fearful stimulus, which leads to greatly reduced fear. Studying animal models of extinction already has lead to better therapeutic strategies and development of new candidate drugs. Lack of a powerful genetic model of extinction, however, has limited progress in identifying underlying molecular and genetic factors. In this study, we established a robust behavioral paradigm to study the short-term effect (acquisition) of extinction in Drosophila melanogaster. We focused on the extinction of olfactory aversive 1-day memory with a task that has been the main workhorse for genetics of memory in flies. Using this paradigm, we show that extinction can inhibit each of two genetically distinct forms of consolidated memory. We then used a series of single-gene mutants with known impact on associative learning to examine the effects on extinction. We find that extinction is intact in each of these mutants, suggesting that extinction learning relies on different molecular mechanisms than does Pavlovian learning.

40 CFR 13.30 - Standards for suspension.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 13.30 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL CLAIMS COLLECTION STANDARDS Suspension of Collection Action § 13.30 Standards for suspension. (a) Inability to locate debtor. The Administrator may suspend collection on a debt where he determines that the debtor cannot be located presently...

Educational Debt in the Context of Career Planning: A Qualitative Exploration of Medical Student Perceptions.

PubMed

Phillips, Julie P; Wilbanks, Deana M; Salinas, Diana F; Doberneck, Diane M

2016-01-01

Phenomenon: Medical students in the United States face increasing educational debt because medical education costs have risen while public investment in higher education has declined. Contemporary students borrow more money and accumulate debt far surpassing that of previous generations of physicians, and both interest rates and terms of loan repayment have changed significantly in the last decade. As a result, the experiences of medical students differ from the experiences of physician educators. Little is known about how contemporary medical students view their debt in the context of career planning. Understanding contemporary U.S. medical students' lived experiences of educational debt is important, because high debt levels may affect medical students' well-being and professional development. The study's purpose was to explore contemporary students' views of their debt in the context of career planning. In 2012, 2nd-year medical students enrolled in a health policy course at one medical school were invited to write an essay about how debt influences their career choices. The authors analyzed 132 essays using immersion and crystallization and iterative, team-based coding. Code-recode strategies, member checking, and reflexivity ensured validity and rigor. Three themes emerged about the meaning of debt: debt symbolizes lack of social investment, debt reinforces a sense of entitlement, and debt is a collective experience. Four approaches to debt management emerged: anticipation, avoidance, acceptance, and disempowerment. Insights: Medical students' views of debt are more complex than previously reported. Medical educators should recognize that many students experience debt as a stressor, acknowledge students' emotions about debt, and invite discussion about the culture of entitlement in medical education and how this culture affects students' professionalism. At the same time, educators should emphasize that students have many repayment options and that regardless of specialty choice, most physicians repay their debts without significant difficulty. Further exploration is needed of the relationships between the amount of debt owed, students' attitudes toward their debt, and other student characteristics. Because students experience debt in a range of ways, more nuanced approaches to understanding and reframing student perceptions of debt are necessary.

Debt-for-nature swaps: A new strategy for protecting environmental interests in developing nations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hamlin, T.B.

1989-01-01

Nature swaps are a generally well-conceived approach to mitigating the destruction of environmentally sensitive areas in developing nations while remaining sensitive to the economic needs of developing countries. They allow developing countries to dedicate some of their debt repayment to local projects, thus benefiting both their economies and the environment. Swaps also help them obtain assistance from environmental organizations in developed nations to manage their own natural resources. Environmentalists, through the purchase of steeply discounted debt, maximize their investment in tropical forest preservation. In addition they can strengthen environmental organizations in developing nations by including local environmentalists in both policymore » decisionmaking and the implementation of conservation projects. Debt-for-nature swaps also keep the subject of tropical deforestation on the agenda of the international community and offer small international lending institutions a socially redeeming means of removing bad loans from their ledgers. Finally, each government's authority to choose its own development objectives is only slightly encumbered by sharing decisionmaking authority with the environmentalists. Essentially, the swapping governments have agreed to cooperate. consequently, tropical forests only have as much protection as the tropical states desire. This does not mean that swaps are of little moment. Hopefully, collaboration between conservationists in the developed world and leaders of the developing nations will contribute to a constructive framework for future efforts to preserve the earth's tropical forests.« less

Debt and foregone medical care.

PubMed

Kalousova, Lucie; Burgard, Sarah A

2013-06-01

Most American households carry debt, yet we have little understanding of how debt influences health behavior, especially health care seeking. We examined associations between foregone medical care and debt using a population-based sample of 914 southeastern Michigan residents surveyed in the wake of the late-2000s recession. Overall debt and ratios of debt to income and debt to assets were positively associated with foregoing medical or dental care in the past 12 months, even after adjusting for the poorer socioeconomic and health characteristics of those foregoing care and for respondents' household incomes and net worth. These overall associations were driven largely by credit card and medical debt, while housing debt and automobile and student loans were not associated with foregoing care. These results suggest that debt is an understudied aspect of health stratification.

A systematic review of financial debt in adolescents and young adults: prevalence, correlates and associations with crime.

PubMed

Hoeve, Machteld; Stams, Geert Jan J M; van der Zouwen, Marion; Vergeer, Margaretha; Jurrius, Kitty; Asscher, Jessica J

2014-01-01

Financial debt in young people has increased in recent years. Because debt may have severe consequences, and it may enhance criminal behavior, insight into the prevalence and determinants of debt and its association with crime is important. We conducted a systematic review and meta-analysis of 36 manuscripts to examine the prevalence of financial debt (k = 23), correlates and risk factors of debt (k = 16), and associations between debt and criminal behavior in adolescents and young adults (k = 8). Findings revealed that the prevalence of debt is substantial among young people; on average, 49% reported to have at least some debt, 22% had financial problems. Older participants and ethnic minorities were found to have higher levels of debt than younger and indigenous counterparts. Females had more financial problems and higher student loans. Low self-esteem, a pro-debt attitude (of young people and their parents), lack of perceived control towards financial management, poor social functioning, financial stress and external locus of control were found to have the strongest associations with debt. Studies reported strong associations between debt and crime. Particularly, strong associations were found between serious and persistent crime in young people and later (young adult) debt or financial problems.

A Systematic Review of Financial Debt in Adolescents and Young Adults: Prevalence, Correlates and Associations with Crime

PubMed Central

Hoeve, Machteld; Stams, Geert Jan J. M.; van der Zouwen, Marion; Vergeer, Margaretha; Jurrius, Kitty; Asscher, Jessica J.

2014-01-01

Financial debt in young people has increased in recent years. Because debt may have severe consequences, and it may enhance criminal behavior, insight into the prevalence and determinants of debt and its association with crime is important. We conducted a systematic review and meta-analysis of 36 manuscripts to examine the prevalence of financial debt (k = 23), correlates and risk factors of debt (k = 16), and associations between debt and criminal behavior in adolescents and young adults (k = 8). Findings revealed that the prevalence of debt is substantial among young people; on average, 49% reported to have at least some debt, 22% had financial problems. Older participants and ethnic minorities were found to have higher levels of debt than younger and indigenous counterparts. Females had more financial problems and higher student loans. Low self-esteem, a pro-debt attitude (of young people and their parents), lack of perceived control towards financial management, poor social functioning, financial stress and external locus of control were found to have the strongest associations with debt. Studies reported strong associations between debt and crime. Particularly, strong associations were found between serious and persistent crime in young people and later (young adult) debt or financial problems. PMID:25136797

Environmental performance, profitability, asset utilization, debt monitoring and firm value

NASA Astrophysics Data System (ADS)

Bukit, R. Br; Haryanto, B.; Ginting, P.

2018-02-01

The growing issue on firm value shows that firm value is not only determined by the firm ability to increase financial profit, but also by the company's concern in maintaining the environmental condition. The industrial development produces waste that pollutes the environment that has potential to serious impact on the next life. In addition to provide financial benefits, companies are increasingly facing pressure to be socially responsible for the survival of the company. However, past findings demonstrate that the effect of environmental performance, profitability, and asset utilization to the firm’s value are still unclear. This study aims to test whether environmental performance, firm profitability and asset utilization can effectively enhance firm value in two different conditions: intensive debt monitoring and less intensive debt monitoring. Sample of companies is taken from the list of Indonesia Stock Exchange during the period of 2013 to 2015. Using multiple regression analysis, discloses that: in intensive monitoring, managers tend to have high firm value when company has high environmental performance and or high profitability and high asset utilization. Monitoring system needs to be intensified especially for companies with the above characteristics.

40 CFR 30.37 - Property trust relationship.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Property trust relationship. 30.37... Property trust relationship. Real property, equipment, intangible property and debt instruments that are acquired or improved with Federal funds shall be held in trust by the recipient as trustee for the...

Endogenous fertility, Ricardian equivalence, and debt management policy.

PubMed

Lapan, H E; Enders, W

1990-03-01

This paper develops a model in which dynastic families optimally determine fertility. Government debt represents a tax on future generations and on childbearing; the Ricardian Equivalence Hypothesis does not hold. Debt is welfare reducing in that it distorts the fertility decision. An increase in government debt induces a decline in fertility and an increase in the steady state capital/labor ratio. If a government inherits an existing stock of debt, the 1st-best policy is to eliminate the debt immediately. In other situations the optimal debt management policy will not, in general, entail a total elimination of the debt.

Pelagic larval duration predicts extinction risk in a freshwater fish clade.

PubMed

Douglas, Morgan; Keck, Benjamin P; Ruble, Crystal; Petty, Melissa; Shute, J R; Rakes, Patrick; Hulsey, C Darrin

2013-01-01

Pelagic larval duration (PLD) can influence evolutionary processes ranging from dispersal to extinction in aquatic organisms. Using estimates of PLD obtained from species of North American darters (Percidae: Etheostomatinae), we demonstrate that this freshwater fish clade exhibits surprising variation in PLD. Comparative analyses provide some evidence that higher stream gradients favour the evolution of shorter PLD. Additionally, similar to patterns in the marine fossil record in which lower PLD is associated with greater extinction probability, we found a reduced PLD in darter lineages was evolutionarily associated with extinction risk. Understanding the causes and consequences of PLD length could lead to better management and conservation of organisms in our increasingly imperiled aquatic environments.

Iraq’s Debt Relief: Procedure and Potential Implications for International Debt Relief

DTIC Science & Technology

2008-10-02

Order Code RL33376 Iraq’s Debt Relief: Procedure and Potential Implications for International Debt Relief Updated October 2, 2008 Martin A. Weiss...4. TITLE AND SUBTITLE Iraq?s Debt Relief: Procedure and Potential Implications for International Debt Relief 5a. CONTRACT NUMBER 5b. GRANT NUMBER...b. ABSTRACT unclassified c. THIS PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 Iraq’s Debt Relief: Procedure

Absolute extinction and the influence of environment - Dark cloud sight lines toward VCT 10, 30, and Walker 67

NASA Technical Reports Server (NTRS)

Cardelli, Jason A.; Clayton, Geoffrey C.

1991-01-01

The range of validity of the average absolute extinction law (AAEL) proposed by Cardelli et al. (1988 and 1989) is investigated, combining published visible and NIR data with IUE UV observations for three lines of sight through dense dark cloud environments with high values of total-to-selective extinction. The characteristics of the data sets and the reduction and parameterization methods applied are described in detail, and the results are presented in extensive tables and graphs. Good agreement with the AAEL is demonstrated for wavelengths from 3.4 microns to 250 nm, but significant deviations are found at shorter wavelengths (where previous studies of lines of sight through bright nebulosity found good agreement with the AAEL). These differences are attributed to the effects of coatings on small-bump and FUV grains.

11 CFR 111.51 - Debts that are covered.

Code of Federal Regulations, 2011 CFR

2011-01-01

...)) Collection of Debts Arising From Enforcement and Administration of Campaign Finance Laws § 111.51 Debts that... antitrust laws. (4) Debts under the Internal Revenue Code of 1986. (5) Debts between the Commission and...

11 CFR 111.51 - Debts that are covered.

Code of Federal Regulations, 2014 CFR

2014-01-01

...)) Collection of Debts Arising From Enforcement and Administration of Campaign Finance Laws § 111.51 Debts that... antitrust laws. (4) Debts under the Internal Revenue Code of 1986. (5) Debts between the Commission and...

11 CFR 111.51 - Debts that are covered.

Code of Federal Regulations, 2013 CFR

2013-01-01

...)) Collection of Debts Arising From Enforcement and Administration of Campaign Finance Laws § 111.51 Debts that... antitrust laws. (4) Debts under the Internal Revenue Code of 1986. (5) Debts between the Commission and...

11 CFR 111.51 - Debts that are covered.

Code of Federal Regulations, 2012 CFR

2012-01-01

...)) Collection of Debts Arising From Enforcement and Administration of Campaign Finance Laws § 111.51 Debts that... antitrust laws. (4) Debts under the Internal Revenue Code of 1986. (5) Debts between the Commission and...

Further evidence of auditory extinction in aphasia.

PubMed

Marshall, Rebecca Shisler; Basilakos, Alexandra; Love-Myers, Kim

2013-02-01

Preliminary research (Shisler, 2005) suggests that auditory extinction in individuals with aphasia (IWA) may be connected to binding and attention. In this study, the authors expanded on previous findings on auditory extinction to determine the source of extinction deficits in IWA. Seventeen IWA (M(age) = 53.19 years) and 17 neurologically intact controls (M(age) = 55.18 years) participated. Auditory stimuli were spoken letters presented in a free-field listening environment. Stimuli were presented in single-stimulus stimulation (SSS) or double-simultaneous stimulation (DSS) trials across 5 conditions designed to determine whether extinction is related to binding, inefficient attention resource allocation, or overall deficits in attention. All participants completed all experimental conditions. Significant extinction was demonstrated only by IWA when sounds were different, providing further evidence of auditory extinction. However, binding requirements did not appear to influence the IWA's performance. Results indicate that, for IWA, auditory extinction may not be attributed to a binding deficit or inefficient attention resource allocation because of equivalent performance across all 5 conditions. Rather, overall attentional resources may be influential. Future research in aphasia should explore the effect of the stimulus presentation in addition to the continued study of attention treatment.

20 CFR 366.2 - Past-due legally enforceable debt.

Code of Federal Regulations, 2010 CFR

2010-04-01

... COLLECTION OF DEBTS BY FEDERAL TAX REFUND OFFSET § 366.2 Past-due legally enforceable debt. A past-due legally enforceable debt which may be referred to the Internal Revenue Service is a debt: (a) Which arose... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Past-due legally enforceable debt. 366.2...

45 CFR 2506.4 - What types of debts are excluded from these regulations?

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false What types of debts are excluded from these...) CORPORATION FOR NATIONAL AND COMMUNITY SERVICE COLLECTION OF DEBTS Introduction § 2506.4 What types of debts are excluded from these regulations? The following types of debts are excluded: (a) Debts or claims...

45 CFR 2506.4 - What types of debts are excluded from these regulations?

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 4 2011-10-01 2011-10-01 false What types of debts are excluded from these...) CORPORATION FOR NATIONAL AND COMMUNITY SERVICE COLLECTION OF DEBTS Introduction § 2506.4 What types of debts are excluded from these regulations? The following types of debts are excluded: (a) Debts or claims...

Student Debt and the Class of 2015. 11th Annual Report

ERIC Educational Resources Information Center

Cochrane, Debbie; Cheng, Diane

2016-01-01

Student Debt and the Class of 2015 is the eleventh annual report on the student loan debt of recent graduates from four-year colleges, documenting the rise in student loan debt and variation among states as well as colleges. This report includes policy recommendations to address rising student debt and reduce debt burdens, including collecting…

Extinction and Star Formation Study in Molecular Clouds with DENIS infrared data and USNO optical data

NASA Astrophysics Data System (ADS)

Cambrésy, Laurent

1999-11-01

This thesis consists in a study of molecular clouds, essentially of the point of view of the interstellar environment, but also of the one of the star formation. The original method to estimate extinction presented here is based on adaptive star counts as well as on a wavelet decomposition. For the first time, an extinction map of the whole sky is proposed (USNO-PMM optical data). Access to very large field maps offers the opportunity to analyze the interstellar matter distribution in various environments. A first result is that the contained mass in regions for which AV > 1 would not exceed half of the total cloud mass. Using DENIS data, it becomes possible to probe dense regions of clouds. For instance, star counts in the Chamaeleon complex show cores which were not resolved before. Moreover, the selection of stars with a strong infrared excess yields about fifty T Tauri candidates. From their luminosity function, I derived the average lifetime of circumstellar disc of low--mass stars: ~4cdot 106 years. It is difficult to understand the relation between extinction and molecular emission, but it appears clearly that molecular emission is a bad estimator of the column density for low extinction area. Actually, thresholds exist in the CO detection and I conclude that photodissociation, density and cloud geometry have important consequences on the CO emission when AV < 2. Investigation of the relation between extinction and far--infrared emission in Polaris leads to a four times larger emissivity in cold areas than in hot areas. This result explains the low temperatures in this cloud and implies severe restrictions concerning the use of far--infrared fluxes as an extinction estimator.

Global microbial carbonate proliferation after the end-Devonian mass extinction: Mainly controlled by demise of skeletal bioconstructors

PubMed Central

Yao, Le; Aretz, Markus; Chen, Jitao; Webb, Gregory E.; Wang, Xiangdong

2016-01-01

Microbial carbonates commonly flourished following mass extinction events. The end-Devonian (Hangenberg) mass extinction event is a first-order mass extinction on the scale of the ‘Big Five’ extinctions. However, to date, it is still unclear whether global microbial carbonate proliferation occurred after the Hangenberg event. The earliest known Carboniferous stromatolites on tidal flats are described from intertidal environments of the lowermost Tournaisian (Qianheishan Formation) in northwestern China. With other early Tournaisian microbe-dominated bioconstructions extensively distributed on shelves, the Qianheishan stromatolites support microbial carbonate proliferation after the Hangenberg extinction. Additional support comes from quantitative analysis of the abundance of microbe-dominated bioconstructions through the Famennian and early Tournaisian, which shows that they were globally distributed (between 40° latitude on both sides of the palaeoequator) and that their abundance increased distinctly in the early Tournaisian compared to the latest Devonian (Strunian). Comparison of variations in the relative abundance of skeleton- versus microbe-dominated bioconstructions across the Hangenberg and ‘Big Five’ extinctions suggests that changes in abundance of skeletal bioconstructors may play a first-order control on microbial carbonate proliferation during extinction transitions but that microbial proliferation is not a general necessary feature after mass extinctions. PMID:28009013

To predict the niche, model colonization and extinction

USGS Publications Warehouse

Yackulic, Charles B.; Nichols, James D.; Reid, Janice; Der, Ricky

2015-01-01

Ecologists frequently try to predict the future geographic distributions of species. Most studies assume that the current distribution of a species reflects its environmental requirements (i.e., the species' niche). However, the current distributions of many species are unlikely to be at equilibrium with the current distribution of environmental conditions, both because of ongoing invasions and because the distribution of suitable environmental conditions is always changing. This mismatch between the equilibrium assumptions inherent in many analyses and the disequilibrium conditions in the real world leads to inaccurate predictions of species' geographic distributions and suggests the need for theory and analytical tools that avoid equilibrium assumptions. Here, we develop a general theory of environmental associations during periods of transient dynamics. We show that time-invariant relationships between environmental conditions and rates of local colonization and extinction can produce substantial temporal variation in occupancy–environment relationships. We then estimate occupancy–environment relationships during three avian invasions. Changes in occupancy–environment relationships over time differ among species but are predicted by dynamic occupancy models. Since estimates of the occupancy–environment relationships themselves are frequently poor predictors of future occupancy patterns, research should increasingly focus on characterizing how rates of local colonization and extinction vary with environmental conditions.

The Changing Fiscal Environment for Academic Veterinary Medicine.

PubMed

Zimmel, Dana N; Lloyd, James W

2015-01-01

The fiscal environment for academic veterinary medicine has changed substantially over the past 50 years. Understanding the flux of state and federal government support and the implications for student debt, academic programs, and scholarly work is critical for planning for the future. The recent precipitous decline in public funding highlights the urgent need to develop and maintain an economically sustainable model that can adapt to the changing landscape and serve societal needs.

Effect of Educational Debt on Emergency Medicine Residents: A Qualitative Study Using Individual Interviews.

PubMed

Young, Timothy P; Brown, Madison M; Reibling, Ellen T; Ghassemzadeh, Sassan; Gordon, Dawn M; Phan, Tammy H; Thomas, Tamara L; Brown, Lance

2016-10-01

In 2001, less than 20% of emergency medicine residents had more than $150,000 of educational debt. Our emergency medicine residents anecdotally reported much larger debt loads. Surveys have reported that debt affects career and life choices. Qualitative approaches are well suited to explore how and why such complex phenomena occur. We aim to gain a better understanding of how our emergency medicine residents experience debt. We conducted individual semistructured interviews with emergency medicine residents. We collected self-reported data related to educational debt and asked open-ended questions about debt influence on career choices, personal life, future plans, and financial decisions. We undertook a structured thematic analysis using a qualitative approach based in the grounded theory method. Median educational debt was $212,000. Six themes emerged from our analysis: (1) debt influenced career and life decisions by altering priorities; (2) residents experienced debt as a persistent source of background stress and felt powerless to change it; (3) residents made use of various techniques to negotiate debt in order to focus on day-to-day work; (4) personal debt philosophy, based on individual values and obtained from family, shaped how debt affected each individual; (5) debt had a normative effect and was acculturated in residency; and (6) residents reported a wide range of financial knowledge, but recognized its importance to career success. Our emergency medicine residents' debt experience is complex and involves multiple dimensions. Given our current understanding, simple solutions are unlikely to be effective in adequately addressing this issue. Copyright © 2016 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.

15 CFR 19.8 - When will Commerce entities suspend or terminate debt collection on a Commerce debt?

Code of Federal Regulations, 2010 CFR

2010-01-01

... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false When will Commerce entities suspend or terminate debt collection on a Commerce debt? 19.8 Section 19.8 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.8 When will...

15 CFR 19.8 - When will Commerce entities suspend or terminate debt collection on a Commerce debt?

Code of Federal Regulations, 2012 CFR

2012-01-01

... 15 Commerce and Foreign Trade 1 2012-01-01 2012-01-01 false When will Commerce entities suspend or terminate debt collection on a Commerce debt? 19.8 Section 19.8 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.8 When will...

15 CFR 19.8 - When will Commerce entities suspend or terminate debt collection on a Commerce debt?

Code of Federal Regulations, 2013 CFR

2013-01-01

... 15 Commerce and Foreign Trade 1 2013-01-01 2013-01-01 false When will Commerce entities suspend or terminate debt collection on a Commerce debt? 19.8 Section 19.8 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.8 When will...

15 CFR 19.8 - When will Commerce entities suspend or terminate debt collection on a Commerce debt?

Code of Federal Regulations, 2011 CFR

2011-01-01

... 15 Commerce and Foreign Trade 1 2011-01-01 2011-01-01 false When will Commerce entities suspend or terminate debt collection on a Commerce debt? 19.8 Section 19.8 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.8 When will...

15 CFR 19.8 - When will Commerce entities suspend or terminate debt collection on a Commerce debt?

Code of Federal Regulations, 2014 CFR

2014-01-01

... 15 Commerce and Foreign Trade 1 2014-01-01 2014-01-01 false When will Commerce entities suspend or terminate debt collection on a Commerce debt? 19.8 Section 19.8 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.8 When will...

Poverty Levels and Debt Indicators among Low-Income Households before and after the Great Recession

ERIC Educational Resources Information Center

Kim, Kyoung Tae; Wilmarth, Melissa J.; Henager, Robin

2017-01-01

This study analyzed the debt profile of low-income households before and after the Great Recession using the 2007, 2010, and 2013 Survey of Consumer Finances (SCF). We used Heckman selection models to investigate three debt characteristics: (a) the amount of debt, (b) debt-to-income ratio, and (c) debt delinquency. Before and after the Great…

36 CFR 1011.8 - When will the Presidio Trust suspend or terminate debt collection on a debt?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false When will the Presidio Trust... PRESIDIO TRUST DEBT COLLECTION Procedures To Collect Presidio Trust Debts § 1011.8 When will the Presidio Trust suspend or terminate debt collection on a debt? If, after pursuing all appropriate means of...

A Memory Retrieval-Extinction Procedure to Prevent Drug Craving and Relapse

PubMed Central

Xue, Yan-Xue; Luo, Yi-Xiao; Wu, Ping; Shi, Hai-Shui; Xue, Li-Fen; Chen, Chen; Zhu, Wei-Li; Ding, Zeng-Bo; Bao, Yan-ping; Shi, Jie; Epstein, David H.; Shaham, Yavin; Lu, Lin

2013-01-01

Drug use and relapse involve learned associations between drug-associated environmental cues and drug effects. Extinction procedures in the clinic can suppress conditioned responses to drug cues, but the extinguished responses typically reemerge after exposure to the drug itself (reinstatement), the drug-associated environment (renewal), or the passage of time (spontaneous recovery). We describe a memory retrieval-extinction procedure that decreases conditioned drug effects and drug seeking in rat models of relapse, and drug craving in abstinent heroin addicts. In rats, daily retrieval of drug-associated memories 10 minutes or 1 hour but not 6 hours before extinction sessions attenuated drug-induced reinstatement, spontaneous recovery, and renewal of conditioned drug effects and drug seeking. In heroin addicts, retrieval of drug-associated memories 10 minutes before extinction sessions attenuated cue-induced heroin craving 1, 30, and 180 days later. The memory retrieval-extinction procedure is a promising nonpharmacological method for decreasing drug craving and relapse during abstinence. PMID:22499948

Financial Literacy at Minority-Serving Institutions

ERIC Educational Resources Information Center

Looney, Shannon M.

2011-01-01

Mounting student debt to cover rising college costs is creating a challenging environment for a number of students pursuing a college degree. For many, a college degree is an avenue to financial success and long-term stability. Most college graduates experience more stable employment, higher income, security through assets, and an overall better…

Fiscal Challenge: An Experiential Exercise in Policy Making

ERIC Educational Resources Information Center

Aguilar, Mike; Soques, Daniel

2015-01-01

In this article, the authors introduce a pedagogical innovation that is designed to enhance students' understanding of fiscal policy in general, and the national debt and deficit in particular. The innovation leverages the educational advantages offered through a competitive environment by pitting teams of students against one another with the…

Emerging Open Online Distance Education Environment

ERIC Educational Resources Information Center

Schroeder, Raymond

2012-01-01

A revolution of sorts is underway in providing open access to rich resources, actual courses, and even entire degrees online. This revolution is fueled by the combination of a bubble in tuition rates, lingering effects of the recession, monumental student debt exceeding one trillion dollars in the United States, development of increasingly…

Extinction learning is slower, weaker and less context specific after alcohol

PubMed Central

Bisby, James A.; King, John A.; Sulpizio, Valentina; Degeilh, Fanny; Valerie Curran, H.; Burgess, Neil

2015-01-01

Alcohol is frequently involved in psychological trauma and often used by individuals to reduce fear and anxiety. We examined the effects of alcohol on fear acquisition and extinction within a virtual environment. Healthy volunteers were administered alcohol (0.4 g/kg) or placebo and underwent acquisition and extinction from different viewpoints of a virtual courtyard, in which the conditioned stimulus, paired with a mild electric shock, was centrally located. Participants returned the following day to test fear recall from both viewpoints of the courtyard. Skin conductance responses were recorded as an index of conditioned fear. Successful fear acquisition under alcohol contrasted with impaired extinction learning evidenced by persistent conditioned responses (Experiment 1). Participants’ impairments in extinction under alcohol correlated with impairments in remembering object-locations in the courtyard seen from one viewpoint when tested from the other viewpoint. Alcohol-induced extinction impairments were overcome by increasing the number of extinction trials (Experiment 2). However, a test of fear recall the next day showed persistent fear in the alcohol group across both viewpoints. Thus, alcohol impaired extinction rather than acquisition of fear, suggesting that extinction is more dependent than acquisition on alcohol-sensitive representations of spatial context. Overall, extinction learning under alcohol was slower, weaker and less context-specific, resulting in persistent fear at test that generalized to the extinction viewpoint. The selective effect on extinction suggests an effect of alcohol on prefrontal involvement, while the reduced context-specificity implicates the hippocampus. These findings have important implications for the use of alcohol by individuals with clinical anxiety disorders. PMID:26234587

7 CFR 1956.102 - Application of policies.

Code of Federal Regulations, 2014 CFR

2014-01-01

...) PROGRAM REGULATIONS (CONTINUED) DEBT SETTLEMENT Debt Settlement-Community and Business Programs § 1956.102 Application of policies. (a) General. If a debt is eligible for settlement, the debt settlement authorities of... in connection with debt settlement will adhere strictly to the authorizations, requirements, and...

7 CFR 1956.102 - Application of policies.

Code of Federal Regulations, 2012 CFR

2012-01-01

...) PROGRAM REGULATIONS (CONTINUED) DEBT SETTLEMENT Debt Settlement-Community and Business Programs § 1956.102 Application of policies. (a) General. If a debt is eligible for settlement, the debt settlement authorities of... in connection with debt settlement will adhere strictly to the authorizations, requirements, and...

7 CFR 1956.102 - Application of policies.

Code of Federal Regulations, 2013 CFR

2013-01-01

...) PROGRAM REGULATIONS (CONTINUED) DEBT SETTLEMENT Debt Settlement-Community and Business Programs § 1956.102 Application of policies. (a) General. If a debt is eligible for settlement, the debt settlement authorities of... in connection with debt settlement will adhere strictly to the authorizations, requirements, and...

7 CFR 1956.102 - Application of policies.

Code of Federal Regulations, 2011 CFR

2011-01-01

...) PROGRAM REGULATIONS (CONTINUED) DEBT SETTLEMENT Debt Settlement-Community and Business Programs § 1956.102 Application of policies. (a) General. If a debt is eligible for settlement, the debt settlement authorities of... in connection with debt settlement will adhere strictly to the authorizations, requirements, and...

Clinically Competent and Fiscally at Risk: Impact of Debt and Financial Parameters on the Surgical Resident.

PubMed

Tevis, Sarah E; Rogers, Andrew P; Carchman, Evie H; Foley, Eugene F; Harms, Bruce A

2018-05-31

While the costs of medical training continue to increase, surgeon income and personal financial decisions may be challenged to manage this expanding debt burden. We sought to characterize the financial liability, assets, income, and debt of surgical residents, and evaluate the necessity for additional financial training. All surgical trainees at a single academic center completed a detailed survey. Questions focused on issues related to debt, equity, cash flow, financial education, and fiscal parameters. Responses were used to calculate debt-to-asset and debt-to-income ratios. Predictors of moderate risk debt-to-asset ratio (0.5 to 0.9), high risk debt-to-asset ratio (≥0.9), and high risk debt-to-income ratio (>0.4) were evaluated. All analyses were performed in SPSS v.21. One hundred five trainees completed the survey (80% response rate), with 38% of respondents reporting greater than $200,000 in educational debt. Overall, 82% of respondents had a moderate or high risk debt-to-asset ratio. Residency program, year, sex, and perception of financial knowledge did not correlate with high risk debt-to-asset ratio. Residents with high debt-to-asset ratios were more likely to have a high level of concern about debt (52% vs 0%, p < 0.001) when compared with residents who had low debt-to-asset ratios. The majority (79%) of respondents felt strongly that inclusion of additional financial training in residency education is a critical need. In a climate of increasingly delayed financial gratification, surgical trainees are on critically unstable financial footing. There is a major gap in current surgical education that requires reassessment for the long-term financial health of residents. Copyright © 2018 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

Associations Between Pharmacy Students' Attitudes Toward Debt, Stress, and Student Loans.

PubMed

Chisholm-Burns, Marie A; Spivey, Christina A; Jaeger, Melanie C; Williams, Jennifer

2017-09-01

Objective. To assess graduating pharmacy students' attitudes toward debt and determine associations with stress, student loan debt, financial need, current employment, post-graduation plans, and expected length of time to repay loans. Methods. Survey was conducted using an attitudes-toward-debt scale (sub-scales: tolerant attitudes toward debt; contemplation and knowledge about loans; fear of debt), Perceived Stress Scale, and questions concerning current employment, estimated total student loan debt, post-graduation plans, and expected length of time to repay loans. Federal loan data were collected using financial aid records. Independent samples t -test, ANOVA, and Pearson's r correlations were conducted. Results. There were 147 students (96.7%) who participated. The majority were female (59.2%), white (69.4%), and had federal student loans (90.5%). Mean total loan amount was $153,276 (SD $59,810), which included federal students loans accumulated before and during pharmacy school. No significant differences were noted on attitudes toward debt or stress based on whether respondents had federal student loans. Greater "fear of debt" was correlated with increased stress, estimated total student loan debt, total federal loan debt, and pharmacy school loan debt. Greater "contemplation and knowledge about loans" was correlated with lower estimated total student loan debt, total federal loan amount, and pharmacy school loan amount. Students with higher "contemplation and knowledge" scores expected to repay loans within a shorter time frame than students with lower scores. Conclusion. Increased fear of debt was related to greater perceived stress and higher student loan amounts borrowed, while increased contemplation and knowledge about loans was associated with lower amounts borrowed. Educational programming concerning loans, debt, and personal financial management may help reduce stress and amount borrowed.

VLT/X-shooter GRBs: Individual extinction curves of star-forming regions★

NASA Astrophysics Data System (ADS)

Zafar, T.; Watson, D.; Møller, P.; Selsing, J.; Fynbo, J. PU; Schady, P.; Wiersema, K.; Levan, A. J.; Heintz, K. E.; Postigo, A. de Ugarte; D'Elia, V.; Jakobsson, P.; Bolmer, J.; Japelj, J.; Covino, S.; Gomboc, A.; Cano, Z.

2018-05-01

The extinction profiles in Gamma-Ray Burst (GRB) afterglow spectral energy distributions (SEDs) are usually described by the Small Magellanic Cloud (SMC)-type extinction curve. In different empirical extinction laws, the total-to-selective extinction, RV, is an important quantity because of its relation to dust grain sizes and compositions. We here analyse a sample of 17 GRBs (0.34

The association of debt financing with not-for-profit hospitals' operational and capital-investment efficiency.

PubMed

Magnus, Stephen A; Wheeler, John R C; Smith, Dean G

2004-01-01

Increased debt in companies can motivate both operational and capital-investment efficiency. This positive influence of debt is attributed to creditors' oversight of corporate behavior and the need to generate cash flows to service debt. Our study investigates whether debt has a similar relationship with efficiency in not-for-profit hospitals. Using statistical analysis of a database of audited financial statements of not-for-profit hospitals, we test whether debt is associated with six distinct measures of operational and capital-investment efficiency. We find that debt either has no association with efficiency or predicts decreased efficiency. Possible explanations are that creditors' oversight is less tight in the not-for-profit setting and that debt may at times motivate excessive capital investment because of a legal requirement to tie tax-exempt debt with a capital-investment project.

Pharmacy Students' Attitudes Toward Debt.

PubMed

Park, Taehwan; Yusuf, Akeem A; Hadsall, Ronald S

2015-05-25

To examine pharmacy students' attitudes toward debt. Two hundred thirteen pharmacy students at the University of Minnesota were surveyed using items designed to assess attitudes toward debt. Factor analysis was performed to identify common themes. Subgroup analysis was performed to examine whether students' debt-tolerant attitudes varied according to their demographic characteristics, past loan experience, monthly income, and workload. Principal component extraction with varimax rotation identified 3 factor themes accounting for 49.0% of the total variance: tolerant attitudes toward debt (23.5%); contemplation and knowledge about loans (14.3%); and fear of debt (11.2%). Tolerant attitudes toward debt were higher if students were white or if they had had past loan experience. These 3 themes in students' attitudes toward debt were consistent with those identified in previous research. Pharmacy schools should consider providing a structured financial education to improve student management of debt.

24 CFR 242.1 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-04-01

.... Debt service coverage ratio is a measure of a hospital's ability to pay interest and principal with cash generated from current operations. Debt service ratio is calculated as follows: Debt Service Coverage Ratio (total debt service coverage on all long-term capital debt) equals the excess of revenues...

24 CFR 242.1 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-04-01

.... Debt service coverage ratio is a measure of a hospital's ability to pay interest and principal with cash generated from current operations. Debt service ratio is calculated as follows: Debt Service Coverage Ratio (total debt service coverage on all long-term capital debt) equals the excess of revenues...

Medical student debt at the Christchurch School of Medicine. The New Zealand Wellbeing, Intentions, Debt and Experiences (WIDE) survey of medical students pilot study. Results part I.

PubMed

Gill, D; Palmer, C; Mulder, R; Wilkinson, T

2001-10-26

To determine the level and sources of medical student debt at the Christchurch School of Medicine. A questionnaire, The New Zealand Wellbeing, Intentions, Debt, and Experiences (WIDE) Survey of Medical Students, was developed and administered to all 204 medical students at the Christchurch School of Medicine and Health Sciences. Included were questions on student demographics, sources and levels of debt, parental financial support, and student perceptions of their debt. The response rate was 88%. International students, whose debt was with an overseas government, and students with mortgages were excluded from the data analysis. The combined total debt for the remaining 165 students was $7775000 with $6290000 (81%) owed to the Government Students Loans scheme. One quarter of 6th year medical students had a debt over $83250, 50% had a debt over $70000, and 75% had a debt over $50000. Student allowances were inaccessible to 64% of 4th and 5th year students and part-time employment during term-time was common. Lack of funds was reported to impair full participation in the medical course. The majority of medical students at the Christchurch School of Medicine accumulate high levels of debt, mainly dtrough the Government Student Loans scheme, during their medical training.

Evaluating the underlying factors behind variable rate debt.

PubMed

McCue, Michael J; Kim, Tae Hyun Tanny

2007-01-01

Recent trends show a greater usage of variable rate debt among health care bond issues. In 2004, 63.4% of the total health care bonds issued were variable rate compared with 30.6% in 1995 (Fitch Ratings, 2005). The purpose of this study is to gain a better understanding of the underlying factors, credit spread, issue characteristics, and issuer factors behind why hospitals and health system borrowers select variable rate debt compared with fixed rate debt. From 2000 to 2004, this study sampled 230 newly issued tax-exempt bonds issued by acute care hospitals and health care systems that included both variable and fixed rate debt issues. Using a logistic regression model, hospitals with variable rate debt issues were assigned a value of 1, whereas hospitals with fixed rate debt issues were assigned a value of 0. This study found a positive association between bond insurance and variable rate debt and a negative association between callable feature and variable rate debt. Facilities located in certificate-of-need states that possessed higher case mix acuity, earned higher profit margins, generated higher debt service coverage, and held less debt were more likely to issue variable rate debt. Overall, hospital managers and board members of hospitals possessing a strong financial performance have an interest in utilizing variable rate debt to lower their cost of capital. In addition, this outcome may also reflect that investment bankers are doing a better job in educating senior hospital management about the interest rate savings benefit of variable rate compared with fixed rate debt.

12 CFR 32.5 - Combination rules.

Code of Federal Regulations, 2011 CFR

2011-01-01

... debt restructuring approved by the OCC, upon request by a bank for application of the non combination... external debt management; and (D) Whether the restructuring includes features of debt or debt-service... generally liable for the debts or actions of the partnership, joint venture, or association, and those...

12 CFR 32.5 - Combination rules.

Code of Federal Regulations, 2012 CFR

2012-01-01

... debt restructuring approved by the OCC, upon request by a bank for application of the non combination... external debt management; and (D) Whether the restructuring includes features of debt or debt-service... generally liable for the debts or actions of the partnership, joint venture, or association, and those...

12 CFR 615.5502 - Issuance of global debt securities.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 12 Banks and Banking 7 2012-01-01 2012-01-01 false Issuance of global debt securities. 615.5502... AFFAIRS, LOAN POLICIES AND OPERATIONS, AND FUNDING OPERATIONS Global Debt Securities § 615.5502 Issuance of global debt securities. (a) The Funding Corporation may provide for the sale of global debt...

12 CFR 615.5502 - Issuance of global debt securities.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 12 Banks and Banking 7 2014-01-01 2014-01-01 false Issuance of global debt securities. 615.5502... AFFAIRS, LOAN POLICIES AND OPERATIONS, AND FUNDING OPERATIONS Global Debt Securities § 615.5502 Issuance of global debt securities. (a) The Funding Corporation may provide for the sale of global debt...

12 CFR 615.5502 - Issuance of global debt securities.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 12 Banks and Banking 7 2013-01-01 2013-01-01 false Issuance of global debt securities. 615.5502... AFFAIRS, LOAN POLICIES AND OPERATIONS, AND FUNDING OPERATIONS Global Debt Securities § 615.5502 Issuance of global debt securities. (a) The Funding Corporation may provide for the sale of global debt...

12 CFR 615.5502 - Issuance of global debt securities.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 12 Banks and Banking 6 2011-01-01 2011-01-01 false Issuance of global debt securities. 615.5502... AFFAIRS, LOAN POLICIES AND OPERATIONS, AND FUNDING OPERATIONS Global Debt Securities § 615.5502 Issuance of global debt securities. (a) The Funding Corporation may provide for the sale of global debt...

29 CFR 20.2 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Definitions. For purposes of this subpart— (a) The term commercial debt means any non-tax business debt in...) The term consumer debt means any non-tax debt of an individual in excess of $100, arising from loans—loan guarantees, overpayments, fines, penalties, or other causes. (c) A debt is considered delinquent...

41 CFR 105-56.010 - Deductions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... delinquent non-tax debt owed to the United States. GSA will pursue, when appropriate, such debt collection... of any nature. If the debt cannot be satisfied from subsequent payments, then the debt will be...) Types of collection. A debt may be collected in one lump sum or in installments. Collection will be by...

48 CFR 32.606 - Debt collection.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Debt collection. 32.606... REQUIREMENTS CONTRACT FINANCING Contract Debts 32.606 Debt collection. (a) If the contractor has not liquidated the debt within 30 days of the date due or requested installment payments or deferment of collection...

12 CFR 541.7 - Corporate debt security.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 12 Banks and Banking 6 2012-01-01 2012-01-01 false Corporate debt security. 541.7 Section 541.7... AFFECTING FEDERAL SAVINGS ASSOCIATIONS § 541.7 Corporate debt security. The term corporate debt security..., note and/or debenture which is commonly regarded as a debt security and is not predominantly...

12 CFR 141.7 - Corporate debt security.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 12 Banks and Banking 1 2013-01-01 2013-01-01 false Corporate debt security. 141.7 Section 141.7... AFFECTING FEDERAL SAVINGS ASSOCIATIONS § 141.7 Corporate debt security. The term corporate debt security..., note and/or debenture which is commonly regarded as a debt security and is not predominantly...

12 CFR 541.7 - Corporate debt security.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 12 Banks and Banking 6 2014-01-01 2012-01-01 true Corporate debt security. 541.7 Section 541.7... AFFECTING FEDERAL SAVINGS ASSOCIATIONS § 541.7 Corporate debt security. The term corporate debt security..., note and/or debenture which is commonly regarded as a debt security and is not predominantly...

12 CFR 141.7 - Corporate debt security.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 12 Banks and Banking 1 2012-01-01 2012-01-01 false Corporate debt security. 141.7 Section 141.7... AFFECTING FEDERAL SAVINGS ASSOCIATIONS § 141.7 Corporate debt security. The term corporate debt security..., note and/or debenture which is commonly regarded as a debt security and is not predominantly...

12 CFR 541.7 - Corporate debt security.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 12 Banks and Banking 5 2011-01-01 2011-01-01 false Corporate debt security. 541.7 Section 541.7... AFFECTING FEDERAL SAVINGS ASSOCIATIONS § 541.7 Corporate debt security. The term corporate debt security..., note and/or debenture which is commonly regarded as a debt security and is not predominantly...

12 CFR 141.7 - Corporate debt security.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 12 Banks and Banking 1 2014-01-01 2014-01-01 false Corporate debt security. 141.7 Section 141.7... AFFECTING FEDERAL SAVINGS ASSOCIATIONS § 141.7 Corporate debt security. The term corporate debt security..., note and/or debenture which is commonly regarded as a debt security and is not predominantly...

12 CFR 541.7 - Corporate debt security.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Corporate debt security. 541.7 Section 541.7... AFFECTING FEDERAL SAVINGS ASSOCIATIONS § 541.7 Corporate debt security. The term corporate debt security..., note and/or debenture which is commonly regarded as a debt security and is not predominantly...

12 CFR 541.7 - Corporate debt security.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 12 Banks and Banking 6 2013-01-01 2012-01-01 true Corporate debt security. 541.7 Section 541.7... AFFECTING FEDERAL SAVINGS ASSOCIATIONS § 541.7 Corporate debt security. The term corporate debt security..., note and/or debenture which is commonly regarded as a debt security and is not predominantly...

Debt and Foregone Medical Care

ERIC Educational Resources Information Center

Kalousova, Lucie; Burgard, Sarah A.

2013-01-01

Most American households carry debt, yet we have little understanding of how debt influences health behavior, especially health care seeking. We examined associations between foregone medical care and debt using a population-based sample of 914 southeastern Michigan residents surveyed in the wake of the late-2000s recession. Overall debt and…

Rethinking Student Loan Debt: Tools and Strategies for Debt Management.

ERIC Educational Resources Information Center

Mason, Susan G.

2001-01-01

Analyzes student loan debt at the University of Missouri-St. Louis School of Optometry, showing the need for a comprehensive debt management program. Presents a model for determining manageable amounts of student loan debt developed from conventional lending criteria and data on earnings for optometrists. (EV)

How well is debt managed by nonprofits?

PubMed

Tuckman, H P; Chang, C F

1993-01-01

Little is known about why nonprofits accrue debt, how much they owe, and whether the funds they borrow are used productively. This article distinguishes between productive, problematic, and deferred debt. Employing a data base representative of 114,726 tax-filing charitable nonprofits in the United States in 1986, it examines the pervasiveness of nonprofit debt and the relation between this debt and nonprofit financial health. The analysis finds that over 70 percent of the nonprofits hold debt, the distribution of this debt is highly concentrated, and the level of debt and leverage varies with asset size and type of activity. Nonprofits with higher leverage and absolute debt levels are financially healthier than those with lower levels. While the analysis does not determine whether financially stronger nonprofits are better able to borrow, the results support the view that borrowing in the nonprofit sector is economically efficient.

Pharmacy Students’ Attitudes Toward Debt

PubMed Central

Yusuf, Akeem A.; Hadsall, Ronald S.

2015-01-01

Objective. To examine pharmacy students’ attitudes toward debt. Methods. Two hundred thirteen pharmacy students at the University of Minnesota were surveyed using items designed to assess attitudes toward debt. Factor analysis was performed to identify common themes. Subgroup analysis was performed to examine whether students’ debt-tolerant attitudes varied according to their demographic characteristics, past loan experience, monthly income, and workload. Results. Principal component extraction with varimax rotation identified 3 factor themes accounting for 49.0% of the total variance: tolerant attitudes toward debt (23.5%); contemplation and knowledge about loans (14.3%); and fear of debt (11.2%). Tolerant attitudes toward debt were higher if students were white or if they had had past loan experience. Conclusion. These 3 themes in students’ attitudes toward debt were consistent with those identified in previous research. Pharmacy schools should consider providing a structured financial education to improve student management of debt. PMID:26089561

Tough choices in tough times: debt and medication nonadherence.

PubMed

Kalousova, Lucie; Burgard, Sarah A

2014-04-01

Debt is a ubiquitous component of households' financial portfolios. Yet we have scant understanding of how household debt constrains spending on needed health care. Diverse types of debt have different financial properties and recent work has shown that they may have varying implications for spending on needed health care. In this article, we explore the associations between indebtedness and medication nonadherence. First, we consider overall debt levels and then we disaggregate debt into types. We use a population-based sample of 434 residents of southeast Michigan who had been prescribed medications, collected in 2009-2010, the wake of the Great Recession. We find no association between medication nonadherence and total indebtedness. However, when we assess each type of debt separately, we find that having medical or credit card debt is positively associated with medication nonadherence, even net of household income, net worth, and other characteristics. Furthermore, patients with greater amounts of medical or credit card debt are more likely to be nonadherent than those with less. Our results suggest that credit card debt and medical debt may have serious implications for the relative affordability of prescription medications. These associations have been overlooked in past research and deserve further examination.

Extinction of Learned Fear Induces Hippocampal Place Cell Remapping

PubMed Central

Wang, Melissa E.; Yuan, Robin K.; Keinath, Alexander T.; Ramos Álvarez, Manuel M.

2015-01-01

The extinction of learned fear is a hippocampus-dependent process thought to embody new learning rather than erasure of the original fear memory, although it is unknown how these competing contextual memories are represented in the hippocampus. We previously demonstrated that contextual fear conditioning results in hippocampal place cell remapping and long-term stabilization of novel representations. Here we report that extinction learning also induces place cell remapping in C57BL/6 mice. Specifically, we observed cells that preferentially remapped during different stages of learning. While some cells remapped in both fear conditioning and extinction, others responded predominantly during extinction, which may serve to modify previous representations as well as encode new safe associations. Additionally, we found cells that remapped primarily during fear conditioning, which could facilitate reacquisition of the original fear association. Moreover, we also observed cells that were stable throughout learning, which may serve to encode the static aspects of the environment. The short-term remapping observed during extinction was not found in animals that did not undergo fear conditioning, or when extinction was conducted outside of the conditioning context. Finally, conditioning and extinction produced an increase in spike phase locking to the theta and gamma frequencies. However, the degree of remapping seen during conditioning and extinction only correlated with gamma synchronization. Our results suggest that the extinction learning is a complex process that involves both modification of pre-existing memories and formation of new ones, and these traces coexist within the same hippocampal representation. PMID:26085635

The extinction law from photometric data: linear regression methods

NASA Astrophysics Data System (ADS)

Ascenso, J.; Lombardi, M.; Lada, C. J.; Alves, J.

2012-04-01

Context. The properties of dust grains, in particular their size distribution, are expected to differ from the interstellar medium to the high-density regions within molecular clouds. Since the extinction at near-infrared wavelengths is caused by dust, the extinction law in cores should depart from that found in low-density environments if the dust grains have different properties. Aims: We explore methods to measure the near-infrared extinction law produced by dense material in molecular cloud cores from photometric data. Methods: Using controlled sets of synthetic and semi-synthetic data, we test several methods for linear regression applied to the specific problem of deriving the extinction law from photometric data. We cover the parameter space appropriate to this type of observations. Results: We find that many of the common linear-regression methods produce biased results when applied to the extinction law from photometric colors. We propose and validate a new method, LinES, as the most reliable for this effect. We explore the use of this method to detect whether or not the extinction law of a given reddened population has a break at some value of extinction. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile (ESO programmes 069.C-0426 and 074.C-0728).

Associations Between Pharmacy Students’ Attitudes Toward Debt, Stress, and Student Loans

PubMed Central

Spivey, Christina A.; Jaeger, Melanie C.; Williams, Jennifer

2017-01-01

Objective. To assess graduating pharmacy students’ attitudes toward debt and determine associations with stress, student loan debt, financial need, current employment, post-graduation plans, and expected length of time to repay loans. Methods. Survey was conducted using an attitudes-toward-debt scale (sub-scales: tolerant attitudes toward debt; contemplation and knowledge about loans; fear of debt), Perceived Stress Scale, and questions concerning current employment, estimated total student loan debt, post-graduation plans, and expected length of time to repay loans. Federal loan data were collected using financial aid records. Independent samples t-test, ANOVA, and Pearson’s r correlations were conducted. Results. There were 147 students (96.7%) who participated. The majority were female (59.2%), white (69.4%), and had federal student loans (90.5%). Mean total loan amount was $153,276 (SD $59,810), which included federal students loans accumulated before and during pharmacy school. No significant differences were noted on attitudes toward debt or stress based on whether respondents had federal student loans. Greater “fear of debt” was correlated with increased stress, estimated total student loan debt, total federal loan debt, and pharmacy school loan debt. Greater “contemplation and knowledge about loans” was correlated with lower estimated total student loan debt, total federal loan amount, and pharmacy school loan amount. Students with higher “contemplation and knowledge” scores expected to repay loans within a shorter time frame than students with lower scores. Conclusion. Increased fear of debt was related to greater perceived stress and higher student loan amounts borrowed, while increased contemplation and knowledge about loans was associated with lower amounts borrowed. Educational programming concerning loans, debt, and personal financial management may help reduce stress and amount borrowed. PMID:29109558

Paleoenvironmental and ecological changes during the Eocene-Oligocene transition based on foraminifera from the Cap Bon Peninsula in North East Tunisia

NASA Astrophysics Data System (ADS)

Grira, Chaima; Karoui-Yaakoub, Narjess; Negra, Mohamed Hédi; Rivero-Cuesta, Lucia; Molina, Eustoquio

2018-07-01

Biostratigraphic analysis of the Eocene-Oligocene transition (E-O) at the Menzel Bou Zelfa and Jhaff composite section in the Cap Bon Peninsula (North East Tunisia) allowed us to recognize a continuous planktic foraminiferal biozonation: E14 Globigerinatheka semiinvoluta Zone, E15 Globigerinatheka index Zone, E16 Hantkenina alabamensis Zone and O1 Pseudohastigerina naguewichiensis Zone. A quantitative study of benthic and planktic foraminifera assemblages was carried out and the richness and diversity of foraminifera allowed us to reconstruct the paleoenvironmental evolution from marine to terrestrial environments. From the Eocene E14 Zone, the foraminiferal association characterizes a relatively warm climate with considerable oxygen content and a dominance of keeled and spinose planktic foraminifera, which became extinct at the E/O boundary, possibly due to cooling of the planktic environment. Nevertheless, the small benthic foraminifera do not show an extinction event at the Eocene/Oligocene (E/O) boundary, indicating that the benthic environment was not significantly affected. In the basal Oligocene O1 Zone, the benthic environment changes to a shallower setting due to cooling of the climate. These changes generated a remarkable dominance of globular forms in the planktic environment. Small benthic foraminifera apparently have a gradual extinction event, or more likely a gradual pattern of local disappearances, that could have been caused by the Oi1 glaciation.

7 CFR 1951.213 - Debt settlement.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 14 2010-01-01 2009-01-01 true Debt settlement. 1951.213 Section 1951.213 Agriculture... and Grants § 1951.213 Debt settlement. Subpart C of part 1956 of this chapter prescribes policies and procedures for debt settlement actions for loans covered under this subpart when it is determined that a debt...

45 CFR 30.13 - Debt reporting and use of credit reporting agencies.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 1 2010-10-01 2010-10-01 false Debt reporting and use of credit reporting... CLAIMS COLLECTION Standards for the Administrative Collection of Debts § 30.13 Debt reporting and use of... over $100 to credit bureaus or other automated databases. Debts arising under the Social Security Act...

75 FR 31736 - Modifications of Debt Instruments

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-04

... that is not debt for Federal income tax purposes, even if the alteration occurs by operation of the... modified debt instrument is debt or some other property right for Federal income tax purposes. However, any... results in an instrument or property right that is not debt for Federal income tax purposes is a [[Page...

45 CFR 32.2 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

...-tax debt to the United States. Delinquent debt means any non-tax debt that has not been paid by the... considered the last day of the period. Debt or claim means an amount of money, funds, or property that has been determined by the Secretary to be owed to the United States by an individual, including debt...

5 CFR 831.1305 - Collection of debts.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Collection of debts. 831.1305 Section 831... (CONTINUED) RETIREMENT Collection of Debts § 831.1305 Collection of debts. (a) Means of collection. Collection of a debt may be made by means of offset under § 831.1306, or under any statutory provision...

20 CFR 367.2 - Past-due legally enforceable debt.

Code of Federal Regulations, 2010 CFR

2010-04-01

... RECOVERY OF DEBTS OWED TO THE UNITED STATES GOVERNMENT BY ADMINISTRATIVE OFFSET § 367.2 Past-due legally enforceable debt. A past-due legally enforceable debt which may be referred to another governmental agency for... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Past-due legally enforceable debt. 367.2...

26 CFR 1.166-1 - Bad debts.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 2 2010-04-01 2010-04-01 false Bad debts. 1.166-1 Section 1.166-1 Internal... TAXES (CONTINUED) Itemized Deductions for Individuals and Corporations § 1.166-1 Bad debts. (a... shall be allowed in respect of bad debts owed to the taxpayer. For this purpose, bad debts shall...

The Race to Refinance Debt: Market Offers Opportunities to Reduce Interest Costs.

ERIC Educational Resources Information Center

DuPont, Lorrie A.

1992-01-01

In this interest market, colleges and universities could benefit from careful evaluation of debt portfolios. Refinancing debt is an opportunity to lower debt service costs, ease cash flow, change security pledges, eliminate debt service reserves, update bond documents. Timing is important. Existing and new bonds can also be combined…

29 CFR 1650.206 - Notification to Treasury.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Regulations Relating to Labor (Continued) EQUAL EMPLOYMENT OPPORTUNITY COMMISSION DEBT COLLECTION Procedures... referring a debt to Treasury, EEOC will certify that the debt meets all of the requirements in § 1650.202..., the amount of the debt, the date on which the debt became past-due, and the designation of EEOC as the...

29 CFR 1650.206 - Notification to Treasury.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Regulations Relating to Labor (Continued) EQUAL EMPLOYMENT OPPORTUNITY COMMISSION DEBT COLLECTION Procedures... referring a debt to Treasury, EEOC will certify that the debt meets all of the requirements in § 1650.202..., the amount of the debt, the date on which the debt became past-due, and the designation of EEOC as the...

29 CFR 1650.206 - Notification to Treasury.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Regulations Relating to Labor (Continued) EQUAL EMPLOYMENT OPPORTUNITY COMMISSION DEBT COLLECTION Procedures... referring a debt to Treasury, EEOC will certify that the debt meets all of the requirements in § 1650.202..., the amount of the debt, the date on which the debt became past-due, and the designation of EEOC as the...

29 CFR 1650.206 - Notification to Treasury.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Regulations Relating to Labor (Continued) EQUAL EMPLOYMENT OPPORTUNITY COMMISSION DEBT COLLECTION Procedures... referring a debt to Treasury, EEOC will certify that the debt meets all of the requirements in § 1650.202..., the amount of the debt, the date on which the debt became past-due, and the designation of EEOC as the...

29 CFR 1650.206 - Notification to Treasury.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Regulations Relating to Labor (Continued) EQUAL EMPLOYMENT OPPORTUNITY COMMISSION DEBT COLLECTION Procedures... referring a debt to Treasury, EEOC will certify that the debt meets all of the requirements in § 1650.202..., the amount of the debt, the date on which the debt became past-due, and the designation of EEOC as the...

31 CFR 351.2 - How do I contact Public Debt?

Code of Federal Regulations, 2010 CFR

2010-07-01

... SERVICE, DEPARTMENT OF THE TREASURY BUREAU OF THE PUBLIC DEBT OFFERING OF UNITED STATES SAVINGS BONDS, SERIES EE General Information § 351.2 How do I contact Public Debt? You may contact Public Debt by e-mail at [email protected], or by writing to the following address: Bureau of the Public Debt...

Evolution and extinction in the marine realm: some constraints imposed by phytoplankton

NASA Technical Reports Server (NTRS)

Knoll, A. H.

1989-01-01

The organic and mineralized remains of planktonic algae provide a rich record of microplankton evolution extending over nearly half of the preserved geological record. In general, Phanerozoic patterns of phytoplankton radiation and extinction parallel those documented for skeletonized marine invertebrates, both augmenting and constraining thought about evolution in the oceans. Rapidly increasing knowledge of Proterozoic plankton is making possible the recognition of additional episodes of diversification and extinction that antedate the Ediacaran radiation of macroscopic animals. In contrast to earlier phytoplankton history, the late Mesozoic and Cainozoic record is documented in sufficient detail to constrain theories of mass extinction in more than a general way. Broad patterns of diversity change in planktonic algae show similarities across the Cretaceous-Tertiary and Eocene-Oligocene boundaries, but detailed comparisons of origination and extinction rates in calcareous nannoplankton, as well as other algae and skeletonized protozoans, suggest that the two episodes were quite distinct. Common causation appears unlikely, casting doubt on monolithic theories of mass extinction, whether periodic or not. Studies of mass extinction highlight a broader class of insights that paleontologists can contribute to evolutionary biology: the evaluation of evolutionary change in the context of evolving Earth-surface environments.

Extinction of opiate reward reduces dendritic arborization and c-Fos expression in the nucleus accumbens core.

PubMed

Leite-Morris, Kimberly A; Kobrin, Kendra L; Guy, Marsha D; Young, Angela J; Heinrichs, Stephen C; Kaplan, Gary B

2014-04-15

Recurrent opiate use combined with environmental cues, in which the drug was administered, provokes cue-induced drug craving and conditioned drug reward. Drug abuse craving is frequently linked with stimuli from a prior drug-taking environment via classical conditioning and associative learning. We modeled the conditioned morphine reward process by using acquisition and extinction of conditioned place preference (CPP) in C57BL/6 mice. Mice were trained to associate a morphine injection with a drug context using a classical conditioning paradigm. In morphine conditioning (0, 0.25, 0.5, 1, 5, or 10 mg/kg) experimental mice acquired a morphine CPP dose response with 10mg/kg as most effective. During morphine CPP extinction experiments, mice were divided into three test groups: morphine CPP followed by extinction training, morphine CPP followed by sham extinction, and saline controls. Extinction of morphine CPP developed within one extinction experiment (4 days) that lasted over two more trials (another 8 days). However, the morphine CPP/sham extinction group retained a place preference that endured through all three extinction trials. Brains were harvested following CPP extinction and processed using Golgi-Cox impregnation. Changes in dendritic morphology and spine quantity were examined in the nucleus accumbens (NAc) Core and Shell neurons. In the NAcCore only, morphine CPP/extinguished mice produced less dendritic arborization, and a decrease in neuronal activity marker c-Fos compared to the morphine CPP/sham extinction group. Extinction of morphine CPP is associated with decreased structural complexity of dendrites in the NAcCore and may represent a substrate for learning induced structural plasticity relevant to addiction. Published by Elsevier B.V.

Venus: A search for clues to early biological possibilities

NASA Technical Reports Server (NTRS)

Colin, Larry; Kasting, James F.

1992-01-01

The extensive evidence that there is no extant life on Venus is summarized. The current atmospheric environment, which is far too hostile by terrestrial standards to support life, is described. However, exobiologists are interested in the possibility of extinct life on Venus. The early history of Venus is discussed in terms of its ability to sustain life that may now be extinct.

Population extinction under bursty reproduction in a time-modulated environment

NASA Astrophysics Data System (ADS)

Vilk, Ohad; Assaf, Michael

2018-06-01

In recent years nondemographic variability has been shown to greatly affect dynamics of stochastic populations. For example, nondemographic noise in the form of a bursty reproduction process with an a priori unknown burst size, or environmental variability in the form of time-varying reaction rates, have been separately found to dramatically impact the extinction risk of isolated populations. In this work we investigate the extinction risk of an isolated population under the combined influence of these two types of nondemographic variation. Using the so-called momentum-space Wentzel-Kramers-Brillouin (WKB) approach and accounting for the explicit time dependence in the reaction rates, we arrive at a set of time-dependent Hamilton equations. To this end, we evaluate the population's extinction risk by finding the instanton of the time-perturbed Hamiltonian numerically, whereas analytical expressions are presented in particular limits using various perturbation techniques. We focus on two classes of time-varying environments: periodically varying rates corresponding to seasonal effects and a sudden decrease in the birth rate corresponding to a catastrophe. All our theoretical results are tested against numerical Monte Carlo simulations with time-dependent rates and also against a numerical solution of the corresponding time-dependent Hamilton equations.

The Federal Government Debt: Its Size and Economic Significance

DTIC Science & Technology

2009-03-04

growth is critical to economic stability . As long as the debt grows more rapidly than output, the ratio of debt to gross domestic product (GDP) will rise...the budget deficit, the rate of interest, and the rate of growth in GDP. What matters most, as far as economic stability is concerned, is what...debt and the overall rate of economic growth is critical to economic stability . As long as the debt grows more rapidly than output, the ratio of debt

The Federal Government Debt: Its Size and Economic Significance

DTIC Science & Technology

2010-02-03

growth rate of the federal debt and the overall rate of economic growth is critical to economic stability . As long as the debt grows more rapidly than...most, as far as economic stability is concerned, is what investors believe to be the long-run outlook for the debt-to-GDP ratio. If large deficits...between the growth rate of the federal debt and the overall rate of economic growth is critical to economic stability . As long as the debt grows more

The use of debt.

PubMed

Hood, W L; Loughery, C V

1990-05-01

Stewards of Catholic healthcare organizations must proceed cautiously before embarking on new construction or renovation projects. Many important issues are involved in financing such projects, including business risk, financial philosophy, financial structure, and forms of debt. The proper foundation for any financing structure must begin with financial philosophy. Some healthcare facilities have traditionally used no external financing; others have employed significant levels of debt. To determine a proper level of debt for the project(s) being financed, it is important to look at business risk. If a modest decline in revenues (or a similar increase in costs) would threaten the project's viability, the business risk would be high; therefore prudence would dictate that the level of debt undertaken be relatively small. A separate analysis is required to determine the appropriate mix of floating-rate and fixed-rate long-term debt. As a rule of thumb, fixed-rate debt would typically form two thirds of the debt structure; floating-rate debt, no more than one third. For healthcare, debt can take two forms: tax exempt and taxable. Tax-exempt financing has many constraints, including use of proceeds by a tax-exempt entity, arbitrage rules, tax legislation, and financial disclosure laws. Taxable debt can be issued by private placement or on a publicly traded basis.

What Can Tobit-Piecewise Regression Tell Us about the Determinants of Household Educational Debt?

ERIC Educational Resources Information Center

Thipbharos, Titirut

2014-01-01

Educational debt as part of household debt remains a problem for Thailand. The significant factors of household characteristics with regard to educational debt are shown by constructing a Tobit-piecewise regression for three different clusters, namely poor, middle and affluent households in Thailand. It was found that household debt is likely to…

12 CFR 313.122 - Notification of debt to FMS.

Code of Federal Regulations, 2010 CFR

2010-01-01

... PROCEDURES FOR CORPORATE DEBT COLLECTION Tax Refund Offset § 313.122 Notification of debt to FMS. The FDIC shall notify FMS of the amount of any past due, legally enforceable non-tax debt owed to it by a person, for the purpose of collecting such debt by tax refund offset. Notification and referral to FMS of such...

45 CFR 2506.7 - Why does the Corporation have to collect debts?

Code of Federal Regulations, 2010 CFR

2010-10-01

... NATIONAL AND COMMUNITY SERVICE COLLECTION OF DEBTS Introduction § 2506.7 Why does the Corporation have to collect debts? Federal agencies are required to try to collect claims or debts of the Federal Government... 45 Public Welfare 4 2010-10-01 2010-10-01 false Why does the Corporation have to collect debts...

7 CFR 792.20 - Reporting discharged debts to IRS.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Government's ability to prove its case in court for the full amount of the debt. (2) The amount of a debt... 7 Agriculture 7 2010-01-01 2010-01-01 false Reporting discharged debts to IRS. 792.20 Section 792..., DEPARTMENT OF AGRICULTURE PROVISIONS COMMON TO MORE THAN ONE PROGRAM DEBT SETTLEMENT POLICIES AND PROCEDURES...

Student Debt and the Class of 2008

ERIC Educational Resources Information Center

Reed, Matthew; Cheng, Diane

2009-01-01

This paper is the fourth annual report on the student loan debt of new college graduates. This analysis of the most recent available data found that student debt continued to rise even as it got harder for recent graduates to find jobs, and that debt levels vary considerably from state to state and college to college. Nationwide, average debt for…

36 CFR 1011.14 - How will the Presidio Trust report debts to credit bureaus?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false How will the Presidio Trust... TRUST DEBT COLLECTION Procedures To Collect Presidio Trust Debts § 1011.14 How will the Presidio Trust report debts to credit bureaus? The Presidio Trust will report delinquent debts to credit bureaus in...

The UNEP State of the Environment Report.

ERIC Educational Resources Information Center

Boyd, Dale

1990-01-01

Presents information from the United Nations Environment Program (UNEP) 1989 State of the World Environment Report. Provides an overview of global environmental concerns, including overpopulation, air and water pollution, global warming, hazardous waste disposal, and species extinction. Reaffirms the need to dedicate research and development…

Partial extinction of a conditioned context enhances preference for elements previously associated with cocaine but not with chocolate.

PubMed

Orsini, C; Bonito-Oliva, A; Montanari, C; Conversi, D; Cabib, S

2013-08-15

Drug-associated stimuli are crucial to reinstatement of drug-seeking after periods of abstinence, representing a central problem in treatment of addiction. The present study investigated the influence of partial extinction of the conditioned context on the expression of conditioned place preference (CPP). Mice of the inbred DBA/2J strain were conditioned with cocaine or chocolate in a context identified by multiple elements (A+B) and subsequently CPP expression was evaluated in a context containing only one element (A or B) or both (A+B). Cocaine- and chocolate-conditioned mice showed CPP in presence of the original compound stimulus. However, cocaine-conditioned mice did not show CPP when tested in A or B context, while chocolate-conditioned mice did show CPP to single element context. After conditioning mice were exposed to extinction training of the context A or B and then tested for CPP 1 and 9 days after the end of the extinction (days 9 and 18). Cocaine-conditioned mice showed CPP 9 days after extinction while chocolate-conditioned mice were relatively insensitive to the extinction procedure on day 1 after extinction, but they did not show CPP for the partial or the original compound 9 days after extinction. Cocaine-conditioned mice not submitted to the extinction training (simple passage of time) or submitted to a Sham-extinction procedure (saline injections and confinement in a new environment) did not show CPP on day 9 or 18. Cocaine-conditioned mice exposed to extinction training showed increased c-Fos expression in several brain areas in comparison to mice exposed to Sham-extinction. The extinction procedure did not specifically reduce behavioral sensitization. The results suggest that extinction training involving only elements of a drug-associated context can result in increased associative strength of those elements. © 2013.

Optical extinction dependence on wavelength and size distribution of airborne dust

NASA Astrophysics Data System (ADS)

Pangle, Garrett E.; Hook, D. A.; Long, Brandon J. N.; Philbrick, C. R.; Hallen, Hans D.

2013-05-01

The optical scattering from laser beams propagating through atmospheric aerosols has been shown to be very useful in describing air pollution aerosol properties. This research explores and extends that capability to particulate matter. The optical properties of Arizona Road Dust (ARD) samples are measured in a chamber that simulates the particle dispersal of dust aerosols in the atmospheric environment. Visible, near infrared, and long wave infrared lasers are used. Optical scattering measurements show the expected dependence of laser wavelength and particle size on the extinction of laser beams. The extinction at long wavelengths demonstrates reduced scattering, but chemical absorption of dust species must be considered. The extinction and depolarization of laser wavelengths interacting with several size cuts of ARD are examined. The measurements include studies of different size distributions, and their evolution over time is recorded by an Aerodynamic Particle Sizer. We analyze the size-dependent extinction and depolarization of ARD. We present a method of predicting extinction for an arbitrary ARD size distribution. These studies provide new insights for understanding the optical propagation of laser beams through airborne particulate matter.

Influence of Feeding and Body Mass on IUCN Extinction Threat of Extant Marine and Terrestrial Mammals

NASA Astrophysics Data System (ADS)

Lam, G.; Wang, I. M.; Heim, N.; Payne, J.

2016-12-01

Extinction is a fundamental phenomenon that has been occurring for millions of years and is critical to the development of new organisms and niches. However, the current extinction rate is now one hundred to a thousand times the past background extinction rate due to human influences and rapidly changing environments. Research on geographic range and life history has been performed in extinction analyses, but rarely any on feeding type and trophic level. We compiled data from the IUCN Red List Database, Paleobiology database and diets from Pauly et al. (1998) to explore the possible correlation between various aspects of ecology and extinction threat. By doing so, we can better understand where to focus our conservation efforts, and what type of approach will reap the best results. We discovered that terrestrial carnivores are slightly less at risk than herbivores and omnivores, and that the feeding and tiering of marine mammals have minimal effect on their IUCN threat level. Body mass is the most influential factor on risk level, with larger adult body masses being most at risk.

Does student debt affect dental students' and dentists' stress levels?

PubMed

Boyles, J D; Ahmed, B

2017-10-27

Introduction Many studies have shown financial worries and debt to induce stress in individuals, this combined with the existing stress of being a dentist raises the question of how student debt affects students' and dentists' stress levels.Objectives Determine whether student debt has had any noticeable effect on student stress levels; investigate whether student debt has any effect on dentists' career choice; investigate whether the increase in tuition fees has influenced the number of applicants to study dentistry at the University of Birmingham.Method Anonymous questionnaires were completed by 70 4th year and 38 5th year BDS and 22 Dental Core Trainees (DCTs). Participants circled the response which best fitted their situation regarding statements on their level of stress and future career path. Ethical approval granted. Application figures to study dentistry obtained from head of admissions.Results Forty-two percent of males and 63% of females strongly agreed with the statement that having no debt would reduce their stress levels. Of those with debt >£40,000, 11% strongly agreed and 42% agreed that their total amount of student debt causes them stress. Whereas, those whose debt is <£40,000 only 2% strongly agreed and 28% agreed that their total amount of student debt causes them stress. Seventy-seven percent of participants who had parental or family financial support reported this reduced their stress levels. Student debt was found to deter females from undertaking further study more than it deters males (P <0.001). Students with a higher level of debt were more likely to worry about their total student loan(s) (P <0.001). Moreover, students with a higher level of debt were more likely to be stressed about their total student loan(s) (P <0.001). Parental/family contribution to student expenses reduces student stress (P <0.001). Applications to study dentistry since the rise in tuition fees have decreased by 42%.Conclusion Student debt has had an impact on student stress; students reporting a higher level of debt also report more stress and concern about paying off their student debt. Having no student debt would reduce stress levels, although to what extent is undetermined. Applications to study dentistry have fallen since the increase in tuition fees.

26 CFR 1.593-7 - Establishment and treatment of reserves for bad debts.

Code of Federal Regulations, 2010 CFR

2010-04-01

....593-10. (2) Bad debt losses. Any bad debt in respect of a nonqualifying loan shall be charged against the reserve for losses on nonqualifying loans, and any bad debt in respect of a qualifying real... option of the taxpayer, however, any bad debt in respect of either class of loans may be charged in whole...

31 CFR 5.2 - Why is the Treasury Department issuing these regulations and what do they cover?

Code of Federal Regulations, 2010 CFR

2010-07-01

... Department employees). (2) This part does not apply to tax debts nor to any debt for which there is an... the Secretary of the Treasury TREASURY DEBT COLLECTION General Provisions § 5.2 Why is the Treasury... collection of Treasury debts. This part also provides procedures for collection of other debts owed to the...

47 CFR 1.1917 - Referrals to the Department of Justice and transfer of delinquent debt to the Secretary of Treasury.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Commission will cease all collection activity related to that debt. (c) All non-tax debts of claims owed to... transfer of delinquent debt to the Secretary of Treasury. 1.1917 Section 1.1917 Telecommunication FEDERAL... of Justice and transfer of delinquent debt to the Secretary of Treasury. (a) Referrals to the...

36 CFR 1011.5 - What interest, penalty charges and administrative costs will the Presidio Trust add to a debt?

Code of Federal Regulations, 2010 CFR

2010-07-01

... charges and administrative costs will the Presidio Trust add to a debt? 1011.5 Section 1011.5 Parks, Forests, and Public Property PRESIDIO TRUST DEBT COLLECTION Procedures To Collect Presidio Trust Debts § 1011.5 What interest, penalty charges and administrative costs will the Presidio Trust add to a debt...

36 CFR 1011.4 - What notice will the Presidio Trust send to a debtor when collecting a debt?

Code of Federal Regulations, 2010 CFR

2010-07-01

... PRESIDIO TRUST DEBT COLLECTION Procedures To Collect Presidio Trust Debts § 1011.4 What notice will the Presidio Trust send to a debtor when collecting a debt? (a) Notice requirements. The Presidio Trust will aggressively collect debts. The Presidio Trust will send at least one written notice to a debtor informing the...

Anticipated debt and financial stress in medical students.

PubMed

Morra, Dante J; Regehr, Glenn; Ginsburg, Shiphra

2008-01-01

While medical student debt is increasing, the effect of debt on student well-being and performance remains unclear. As a part of a larger study examining medical student views of their future profession, data were collected to examine the role that current and anticipated debt has in predicting stress among medical students. A survey was administered to medical students in all four years at the University of Toronto. Of the 804 potential respondents across the four years of training, 549 surveys had sufficient data for inclusion in this analysis, for a response rate of 68%. Through multiple regression analysis, we evaluated the correlation between current and anticipated debt and financial stress. Although perceived financial stress correlates with both current and anticipated debt levels, anticipated debt was able to account for an additional 11.5% of variance in reported stress when compared to current debt levels alone. This study demonstrates a relationship between perceived financial stress and debt levels, and suggests that anticipated debt levels might be a more robust metric to capture financial burden, as it standardizes for year of training and captures future financial liabilities (future tuition and other future expenses).

Student Debt Spans Generations: Characteristics of Parents Who Borrow to Pay for Their Children's College Education.

PubMed

Walsemann, Katrina M; Ailshire, Jennifer A

2017-10-01

Discussions of student debt often overlook the debt parents take on to pay for their children's education. We identify characteristics of parents with child-related educational debt among the late baby boom cohort. Data come from the National Longitudinal Survey of Youth 1979, a nationally representative sample of individuals born between 1957 and 1964. We restrict our sample to parents who had any children aged ≥17 and answered questions on educational debt during midlife (n = 6,562). Craggit models estimated (a) having any child-related educational debt and (b) the amount of debt owed among debtors. Black parents and parents with more education, higher income, and higher net worth were more likely to report child-related educational debt than White parents and parents with no degree, low-income, or negative net worth. Among debtors, high-income parents had more debt than low-income parents. Our findings suggest concerns about the student debt crisis should extend to aging parents. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

A First Investigation of the UV Extinction Properties of Interstellar Dust in M33

NASA Astrophysics Data System (ADS)

Clayton, Geoffrey

2017-08-01

It is well known that the standard Milky Way UV extinction curve does not hold even in the most nearby galaxies, the LMC and the SMC. But, it is not even known whether the standard curve holds throughout our own galaxy because our position in the disk of the Milky Way, where extinction is high, prevents us from seeing most of our galaxy at UV wavelengths. We have a unique opportunity, while we still have the capability to obtain UV spectra, to investigate the UV extinction properties across another spiral galaxy in the Local Group, M33. The small aperture and high sensitivity of HST/STIS are ideal for obtaining UV spectra of stars in the crowded fields of M33. We propose to observe 8 stars in M33 which will provide good spatial coverage. We are choosing sightlines that lie in the footprint of the M33 Legacy Survey which extends the Panchromatic Hubble Andromeda Treasury (PHAT) survey. Focusing our study on the detailed properties of M33 dust grains via UV spectroscopy with HST/STIS will mean that we can directly connect the variations seen in the UV extinction curves with their environments. By selecting our sightlines in the M33 PHAT survey region, we will be able to probe a variety of potential correlations between dust grains and their environment. This proposal is part of a long-term program to investigate the extinction properties of interstellar dust across a sample of Local Group galaxies, also including M31, with different global characteristics such as metallicity and star formation activity. There is a metallicity gradient across M33 from solar to sub-solar that will be sampled with our proposed sightlines.

Extinction risk and eco-evolutionary dynamics in a variable environment with increasing frequency of extreme events

PubMed Central

Vincenzi, Simone

2014-01-01

One of the most dramatic consequences of climate change will be the intensification and increased frequency of extreme events. I used numerical simulations to understand and predict the consequences of directional trend (i.e. mean state) and increased variability of a climate variable (e.g. temperature), increased probability of occurrence of point extreme events (e.g. floods), selection pressure and effect size of mutations on a quantitative trait determining individual fitness, as well as the their effects on the population and genetic dynamics of a population of moderate size. The interaction among climate trend, variability and probability of point extremes had a minor effect on risk of extinction, time to extinction and distribution of the trait after accounting for their independent effects. The survival chances of a population strongly and linearly decreased with increasing strength of selection, as well as with increasing climate trend and variability. Mutation amplitude had no effects on extinction risk, time to extinction or genetic adaptation to the new climate. Climate trend and strength of selection largely determined the shift of the mean phenotype in the population. The extinction or persistence of the populations in an ‘extinction window’ of 10 years was well predicted by a simple model including mean population size and mean genetic variance over a 10-year time frame preceding the ‘extinction window’, although genetic variance had a smaller role than population size in predicting contemporary risk of extinction. PMID:24920116

Endolithic microbial model for Martian exobiology: The road to extinction

NASA Technical Reports Server (NTRS)

Oscampo-Friedmann, R.; Friedmann, E. I.

1991-01-01

Martian exobiology is based on the assumption that on early Mars, liquid water was present and that conditions were suitable for the evolution of life. The cause for life to disappear from the surface and the recognizable fingerprints of past microbial activity preserved on Mars are addressed. The Antarctic cryptoendolithic microbial ecosystem as a model for extinction in the deteriorating Martian environment is discussed.

Public Debt: Private Asset. Government Debt and Its Role in the Economy.

ERIC Educational Resources Information Center

Schilling, Tim

In 1981, the United States reached a dubious economic milestone--the federal debt surpassed one trillion dollars for the first time. It took more than 200 years to build up that much debt. The federal debt doubled to two trillion by 1986, hit the three trillion level in 1990, and stands at an estimated five-and-a-half trillion for 1998. Just as…

Early life programming of innate fear and fear learning in adult female rats.

PubMed

Stevenson, Carl W; Meredith, John P; Spicer, Clare H; Mason, Rob; Marsden, Charles A

2009-03-02

The early rearing environment can impact on emotional reactivity and learning later in life. In this study the effects of neonatal maternal separation (MS) on innate fear and fear learning were assessed in the adult female rat. Pups were subjected to MS (360 min), brief handling (H; 15 min), or animal facility rearing (AFR) on post-natal days 2-14. In the first experiment, innate fear was tested in the open field. No differences between the early rearing groups were observed in unconditioned fear. In the second experiment, separate cohorts were used in a 3-day fear learning paradigm which tested the acquisition (Day 1), expression and extinction (both Day 2) of conditioning to an auditory cue; extinction recall was determined as well (Day 3). Contextual fear conditioning was also assessed prior to cue presentations on Days 2 and 3. Whereas MS attenuated the acquisition and expression of fear conditioning to the cue, H potentiated extinction learning. Cue-induced fear was reduced on Day 3, compared to Day 2, indicating that the recall of extinction learning was evident; however, no early rearing group differences in extinction recall were observed. Similarly, while contextual fear was decreased on Day 3, compared to Day 2, there were no differences between the early rearing groups on either day tested. The present findings of altered cue-conditioned fear learning, in the absence of innate fear changes, lend further support for the important role of the early rearing environment in mediating cognition in adulthood.

An allometric approach to quantify the extinction vulnerability of birds and mammals.

PubMed

Hilbers, J P; Schipper, A M; Hendriks, A J; Verones, F; Pereira, H M; Huijbregts, M A J

2016-03-01

Methods to quantify the vulnerability of species to extinction are typically limited by the availability of species-specific input data pertaining to life-history characteristics and population dynamics. This lack of data hampers global biodiversity assessments and conservation planning. Here, we developed a new framework that systematically quantifies extinction risk based on allometric relationships between various wildlife demographic parameters and body size. These allometric relationships have a solid theoretical and ecological foundation. Extinction risk indicators included are (1) the probability of extinction, (2) the mean time to extinction, and (3) the critical patch size. We applied our framework to assess the global extinction vulnerability of terrestrial carnivorous and non-carnivorous birds and mammals. Irrespective of the indicator used, large-bodied species were found to be more vulnerable to extinction than their smaller counterparts. The patterns with body size were confirmed for all species groups by a comparison with IUCN data on the proportion of extant threatened species: the models correctly predicted a multimodal distribution with body size for carnivorous birds and a monotonic distribution for mammals and non-carnivorous birds. Carnivorous mammals were found to have higher extinction risks than non-carnivores, while birds were more prone to extinction than mammals. These results are explained by the allometric relationships, predicting the vulnerable species groups to have lower intrinsic population growth rates, smaller population sizes, lower carrying capacities, or larger dispersal distances, which, in turn, increase the importance of losses due to environmental stochastic effects and dispersal activities. Our study is the first to integrate population viability analysis and allometry into a novel, process-based framework that is able to quantify extinction risk of a large number of species without requiring data-intensive, species-specific information. The framework facilitates the estimation of extinction vulnerabilities of data-deficient species. It may be applied to forecast extinction vulnerability in response to a changing environment, by incorporating quantitative relationships between wildlife demographic parameters and environmental drivers like habitat alteration, climate change, or hunting.

Activation of AMPA receptor in the infralimbic cortex facilitates extinction and attenuates the heroin-seeking behavior in rats.

PubMed

Chen, Weisheng; Wang, Yiqi; Sun, Anna; Zhou, Linyi; Xu, Wenjin; Zhu, Huaqiang; Zhuang, Dingding; Lai, Miaojun; Zhang, Fuqiang; Zhou, Wenhua; Liu, Huifen

2016-01-26

Infralimbic cortex (IL) is proposed to suppress cocaine seeking after extinction, but whether the IL regulates the extinction and reinstatement of heroin-seeking behavior is unknown. To address this issue, the male SD rats were trained to self-administer heroin under a FR1 schedule for consecutive 14 days, then the rats underwent 7 daily 2h extinction session in the operant chamber. The activation of IL by microinjection PEPA, an allosteric AMPA receptor potentiator into IL before each of extinction session facilitated the extinction responding after heroin self-administration, but did not alter the locomotor activity in an open field testing environment. Other rats were first trained under a FR1 schedule for heroin self-administration for 14 days, followed by 14 days of extinction training, and reinstatement of heroin-seeking induced by cues was measured for 2h. Intra-IL microinjecting of PEPA at 15min prior to test inhibited the reinstatement of heroin-seeking induced by cues. Moreover, the expression of GluR1 in the IL and NAc remarkably increased after treatment with PEPA during the reinstatement. These finding suggested that activation of glutamatergic projection from IL to NAc shell may be involved in the extinction and reinstatement of heroin-seeking. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

78 FR 3498 - Debt Management Advisory Committee Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-16

... DEPARTMENT OF THE TREASURY Departmental Offices Debt Management Advisory Committee Meeting Notice.... of the following debt management advisory committee: Treasury Borrowing Advisory Committee of The... decisions on major financing operations. Historically, this advice has been offered by debt management...

Attractiveness of family medicine for medical students: influence of research and debt.

PubMed

Vanasse, Alain; Orzanco, Maria Gabriela; Courteau, Josiane; Scott, Sarah

2011-06-01

To examine the association between students' personal characteristics, backgrounds, and medical schools and their intention to enter a family medicine (FM) specialty. Descriptive study using data from the 2007 National Physician Survey. Canada. Clinical (n=1109) and preclinical (n=829) medical student respondents to the 2007 National Physician Survey. The main variable was hoping to enter an FM specialty, and 40 independent variables were included in regression and classification-tree models. Fewer than 1 medical student in 3 (30.2% at the preclinical level and 31.4% at the clinical level) hoped to enter into an FM career. Those who did were more likely to be female, were slightly older, were more frequently married or living with partners, were typically born in Canada, and were more likely to have previous exposure to non-urban environments. The most important predictor for both populations was the debt related to medical studies, which acted in the opposite direction of whether or not students were interested in research. Students interested in research were attracted by specialties with high earning potential, while those not interested in research looked for short residency programs, such as FM, so they could begin to pay off debt sooner. Therefore, the interest in research appears to be inversely related to the choice of FM. Less than one-third of medical students were looking for residencies in FM in Canada. This is far below the goals of 45% set at the national level and 50% set by some provinces like Quebec. Debt and interest in research have strong influences on the choice of residency by medical students.

Spontaneous growth of polarizing refractory metal ‘nano-fins’

NASA Astrophysics Data System (ADS)

Tai, M. C.; Gentle, A. R.; Arnold, M. D.; Cortie, M. B.

2018-03-01

Traditional polymer polarizers degrade in harsh environments and at high temperatures, reducing the polarization effect. In contrast, polarizers produced with refractory metals have vastly improved thermal stability and resistance to harsh environments but are expensive to fabricate. Here we demonstrate prototype refractory metal wire grid polarizers produced by co-sputtering molybdenum and aluminum under specific conditions. Removal of the aluminum through selective dissolution enables the nanostructure array to transmit light. The polarization spans 500-1100 nm and the extinction ratio significantly increases to >100. Possessing broadband polarization and sufficient extinction ratios, the new polarizing film has potential applications in coatings for sunglasses, windows, pyrometers, scientific instruments, and LCD panels.

Causes of the great mass extinction of marine organisms in the Late Devonian

NASA Astrophysics Data System (ADS)

Barash, M. S.

2016-11-01

The second of the five great mass extinctions of the Phanerozoic occurred in the Late Devonian. The number of species decreased by 70-82%. Major crises occurred at the Frasnian-Famennian and Devonian-Carboniferous boundary. The lithological and geochemical compositions of sediments, volcanic deposits, impactites, carbon and oxygen isotope ratios, evidence of climate variability, and sea level changes reflect the processes that led the critical conditions. Critical intervals are marked by layers of black shales, which were deposited in euxinic or anoxic environments. These conditions were the main direct causes of the extinctions. The Late Devonian mass extinction was determined by a combination of impact events and extensive volcanism. They produced similar effects: emissions of harmful chemical compounds and aerosols to cause greenhouse warming; darkening of the atmosphere, which prevented photosynthesis; and stagnation of oceans and development of anoxia. Food chains collapsed and biological productivity decreased. As a result, all vital processes were disturbed and a large portion of the biota became extinct.

77 FR 54862 - Integrated Hedging Transactions of Qualifying Debt

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-06

... Integrated Hedging Transactions of Qualifying Debt AGENCY: Internal Revenue Service (IRS), Treasury. ACTION... certain integrated transactions that involve a foreign currency denominated debt instrument and multiple... foreign currency denominated debt instrument and multiple associated hedging transactions. The text of...

45 CFR 1150.30 - Which debts can the Endowment refer to the Treasury for collection by offsetting tax refunds?

Code of Federal Regulations, 2010 CFR

2010-10-01

... ENDOWMENT FOR THE ARTS COLLECTION OF CLAIMS Tax Refund Offset § 1150.30 Which debts can the Endowment refer... enforceable debt referable to the Treasury for tax refund offset is a debt that is owed to the Endowment and... the Treasury regulations relating to the eligibility of a debt for tax return offset (31 CFR 285.2...

Genetic Counseling Graduate Student Debt: Impact on Program, Career and Life Choices

PubMed Central

Kuhl, Ashley; Reiser, Catherine; Eickhoff, Jens; Petty, Elizabeth M

2015-01-01

The cost of education is rising, increasing student financial aid and debt for students pursuing higher education. A few studies have assessed the impact of student debt in medicine, physical therapy and social work, but little is known about the impact of student debt on genetic counseling students and graduates. To address this gap in knowledge, a web-based study of 408 recent alumni of genetic counseling programs in North America was conducted to assess the impact of student debt on program, career and life choices. Over half (63%; n=256/408) of the participants reported that loans were extremely important in their ability to attend their training program, with most using subsidized loans no longer available to current graduate students. While participants were generally satisfied with their genetic counseling education, 83% (n=282/342) of participants with student debt reported feeling burdened by their debt, which had a median of $40,000-$50,000. This debt is relatively close to the median starting salary reported by survey participants ($45,000-$50,000), breaching the “20-10 rule” that states student debt should not exceed 20% of annual net income. In response to this critical issue, we propose recommendations for the genetic counseling field that may help alleviate student debt impact and burden. PMID:24578121

Rising levels of New Zealand medical student debt.

PubMed

Verstappen, Antonia; Poole, Phillippa

2017-06-16

There is little recent data on the debt levels accrued by New Zealand medical graduates. We aimed to quantify the level of student loan debt accrued by medical graduates upon completion of their medical degree, and to investigate the association of New Zealand Government Student Loan (GSL) debt with gender and age. At graduation each year from 2006-2015, students from one New Zealand medical programme were invited to complete a career intention survey that included information on levels of GSL debt and the number of income sources used. The overall response rate was 83.8%. On average, 92% of domestic students reported having some student loan debt, with 28% a debt of $90,000 or more. The proportion of students reporting a student loan debt of $90,000 or more increased over the period of the study (P<0.0001). While older students were more likely to have a larger student loan debt than younger students, there was no difference in debt levels by gender. Students with larger student loans were more likely to rely on a larger number of financial sources to fund their studies. New Zealand medical students are carrying higher levels of student loan debt year on year. The effect of this on the future medical workforce is not certain; however, this could be negative if graduates choose to enter careers that are more highly paid over areas of high need. The full impact of large loans on individuals and the health system will take years to determine.

Take a Strategic Direction with Debt.

ERIC Educational Resources Information Center

Augustine, John H.

2002-01-01

Offers advice to higher education institutions about financing decisions on their debt portfolios. Addresses developing a debt management framework, factors affecting strategy, interest rate management, establishing a debt management benchmark, and adopting a prospective approach. Sidebars discuss the trade-offs of credit offerings, and…

The future of the oceans past.

PubMed

Jackson, Jeremy B C

2010-11-27

Major macroevolutionary events in the history of the oceans are linked to changes in oceanographic conditions and environments on regional to global scales. Even small changes in climate and productivity, such as those that occurred after the rise of the Isthmus of Panama, caused major changes in Caribbean coastal ecosystems and mass extinctions of major taxa. In contrast, massive influxes of carbon at the end of the Palaeocene caused intense global warming, ocean acidification, mass extinction throughout the deep sea and the worldwide disappearance of coral reefs. Today, overfishing, pollution and increases in greenhouse gases are causing comparably great changes to ocean environments and ecosystems. Some of these changes are potentially reversible on very short time scales, but warming and ocean acidification will intensify before they decline even with immediate reduction in emissions. There is an urgent need for immediate and decisive conservation action. Otherwise, another great mass extinction affecting all ocean ecosystems and comparable to the upheavals of the geological past appears inevitable.

The future of the oceans past

PubMed Central

Jackson, Jeremy B. C.

2010-01-01

Major macroevolutionary events in the history of the oceans are linked to changes in oceanographic conditions and environments on regional to global scales. Even small changes in climate and productivity, such as those that occurred after the rise of the Isthmus of Panama, caused major changes in Caribbean coastal ecosystems and mass extinctions of major taxa. In contrast, massive influxes of carbon at the end of the Palaeocene caused intense global warming, ocean acidification, mass extinction throughout the deep sea and the worldwide disappearance of coral reefs. Today, overfishing, pollution and increases in greenhouse gases are causing comparably great changes to ocean environments and ecosystems. Some of these changes are potentially reversible on very short time scales, but warming and ocean acidification will intensify before they decline even with immediate reduction in emissions. There is an urgent need for immediate and decisive conservation action. Otherwise, another great mass extinction affecting all ocean ecosystems and comparable to the upheavals of the geological past appears inevitable. PMID:20980323

In Sickness and in Debt: Do Mounting Medical Bills Predict Payday Loan Debt?

PubMed

Bickham, Trey; Lim, Younghee

2015-01-01

Cash-strapped families sometimes turn to small, short-term loans with exorbitant fees—payday loans—to cope with mounting medical bills. Given that about three-fourths of payday loan customers are repeat borrowers, consumer advocates and policymakers have increasingly raised voices of concern about the use of payday loans to finance various household expenses, including, among other things, medical bills. The present study hypothesized that increases in medical debt are associated with increases in payday loan debt among a sample of Chapter 7 bankruptcy filers. The results of a multivariate tobit regression analysis showed that medical debt was associated with increased payday loan debt, controlling for various types of debt and other socioeconomic variables. This article concludes with implications of the results for social work policy- and direct-practice.

The contribution of fiscal/financial decentralization to the debt expansion of the local financing platform

NASA Astrophysics Data System (ADS)

Huayang, Yin; Di, Zhou; Bing, Cui

2018-02-01

Using soft budget theory to explore the formation mechanism and the deep institutional incentive of the local financing platform debt expansion from the perspective of fiscal / financial decentralization, construct theoretical framework which explain the expansion of local debt financing platform and conduct an empirical test, the results showed that the higher the degree of fiscal decentralization, fiscal autonomy as a soft constraint body of local government the stronger, local financing platform debt scale is greater; the higher the degree of financial decentralization, local government and financial institutions have the higher autonomy with respect to the central, local financing platform debt scale is bigger; financial synergy degree is stronger, local government financial mutual supervision prompted the local government debt more transparency, local debt financing platform size is smaller.

Survey of emergency medicine resident debt status and financial planning preparedness.

PubMed

Glaspy, Jeffrey N; Ma, O John; Steele, Mark T; Hall, Jacqueline

2005-01-01

Most resident physicians accrue significant financial debt throughout their medical and graduate medical education. The objective of this study was to analyze emergency medicine resident debt status, financial planning actions, and educational experiences for financial planning and debt management. A 22-item questionnaire was sent to all 123 Accreditation Council on Graduate Medical Education-accredited emergency medicine residency programs in July 2001. Two follow-up mailings were made to increase the response rate. The survey addressed four areas of resident debt and financial planning: 1) accrued debt, 2) moonlighting activity, 3) financial planning/debt management education, and 4) financial planning actions. Descriptive statistics were used to analyze the data. Survey responses were obtained from 67.4% (1,707/2,532) of emergency medicine residents in 89 of 123 (72.4%) residency programs. Nearly one half (768/1,707) of respondents have accrued more than 100,000 dollars of debt. Fifty-eight percent (990/1,707) of all residents reported that moonlighting would be necessary to meet their financial needs, and more than 33% (640/1,707) presently moonlight to supplement their income. Nearly one half (832/1,707) of residents actively invested money, of which online trading was the most common method (23.3%). Most residents reported that they received no debt management education during residency (82.1%) or medical school (63.7%). Furthermore, 79.1% (1,351/1,707) of residents reported that they received no financial planning lectures during residency, although 84.2% (1,438/1,707) reported that debt management and financial planning education should be available during residency. Most emergency medicine residency programs do not provide their residents with financial planning education. Most residents have accrued significant debt and believe that more financial planning and debt management education is needed during residency.

Is Medical Student Choice of a Primary Care Residency Influenced by Debt?

PubMed Central

Kahn, Marc J.; Markert, Ronald J.; Lopez, Fred A.; Specter, Steven; Randall, Howard; Krane, N. Kevin

2006-01-01

Context The average medical student accumulates more than $120,000 in debt upon graduation. Objective The purpose of this study was to investigate whether medical student debt affects residency choice. Design This was a cross-sectional research study. Setting This study was a 5-year analysis of student debt and residency choice for 2001–2005 graduates from 3 US medical schools (n = 2022): Tulane University School of Medicine, New Orleans, Louisiana; University of South Florida College of Medicine, Tampa, Florida; and Louisiana State University School of Medicine in New Orleans. Main outcome measures Individual student data were collected from offices of financial aid for debt prior to and during medical school to determine total debt at graduation. Total debt (adjusted for inflation) was compared with residency match results coded according to specialties listed in the Graduate Medical Education Directory 2005–2006. Graduates were coded into either primary care (PC) or nonprimary care (NPC) specialty categories. Logistic regression for the choice of a PC residency was used with 4 predictors: (1) total debt, (2) medical school, (3) year of graduation, and (4) number of years of training required for a residency program. Results Mean total debt for the study population was $89,807 (SD = 54,925). Graduates entering PC did not have significantly less total debt than those entering NPC ($87,206 vs $91,430; P = .09). Further, total debt was not a predictor of a PC residency after adjusting for medical school, year of graduation, and years of training in residency (P = .64). Conclusion There is no association between PC residency choice and debt. We conclude that medical students make residency decisions on the basis of a complex set of factors. PMID:17415301

Parental Debt and Children's Socioemotional Well-being.

PubMed

Berger, Lawrence M; Houle, Jason N

2016-02-01

We estimated associations between total amount of parental debt and of home mortgage, student loan, automobile, and unsecured debt with children's socioemotional well-being. We used population-based longitudinal data from the National Longitudinal Study of Youth 1979 Cohort and Children of the National Longitudinal Study of Youth 1979 Cohort. Our analytic sample consisted of 29 318 child-year observations of 9011 children and their mothers observed annually or biennially from 1986 to 2008. We used the Behavioral Problems Index to measure socioemotional well-being. We used ordinary least squares regressions to estimate between-child associations of amounts and types of parental debt with socioemotional well-being, net of a host of control variables, and regressions with child-specific fixed effects to estimate within-child associations of changes in parental debt with changes in socioemotional well-being, net of all time-constant observed and unobserved confounders. Greater total debt was associated with poorer child socioemotional well-being. However, this association varied by type of debt. Specifically, higher levels of home mortgage and education debt were associated with greater socioemotional well-being for children, whereas higher levels of and increases in unsecured debt were associated with lower levels of and declines in child socioemotional well-being. Debt that allows for investment in homes (and perhaps access to better neighborhoods and schools) and parental education is associated with greater socioemotional well-being for children, whereas unsecured debt is negatively associated with socioemotional development, which may reflect limited financial resources to invest in children and/or parental financial stress. This suggests that debt is not universally harmful for children's well-being, particularly if used to invest in a home or education. Copyright © 2016 by the American Academy of Pediatrics.

7 CFR 1951.894 - Debt settlement.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 14 2010-01-01 2009-01-01 true Debt settlement. 1951.894 Section 1951.894 Agriculture... REGULATIONS (CONTINUED) SERVICING AND COLLECTIONS Rural Development Loan Servicing § 1951.894 Debt settlement. Debt settlement of all claims will be handled in accordance with the Federal Claims Collection...

7 CFR 1956.136 - Chargeoff.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 14 2010-01-01 2009-01-01 true Chargeoff. 1956.136 Section 1956.136 Agriculture... REGULATIONS (CONTINUED) DEBT SETTLEMENT Debt Settlement-Community and Business Programs § 1956.136 Chargeoff. (a) Judgment debts. Subject to the provisions of § 1956.112(d) of this subpart, judgment debts...

12 CFR 37.8 - Safety and soundness requirements.

Code of Federal Regulations, 2011 CFR

2011-01-01

... effective risk management and control processes over its debt cancellation contracts and debt suspension... manage the risks associated with debt cancellation contracts and debt suspension agreements in accordance... the products. A bank also should assess the adequacy of its internal control and risk mitigation...

48 CFR 31.205-3 - Bad debts.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Bad debts. 31.205-3... REQUIREMENTS CONTRACT COST PRINCIPLES AND PROCEDURES Contracts With Commercial Organizations 31.205-3 Bad debts. Bad debts, including actual or estimated losses arising from uncollectible accounts receivable due...

12 CFR 37.8 - Safety and soundness requirements.

Code of Federal Regulations, 2010 CFR

2010-01-01

... effective risk management and control processes over its debt cancellation contracts and debt suspension... manage the risks associated with debt cancellation contracts and debt suspension agreements in accordance... the products. A bank also should assess the adequacy of its internal control and risk mitigation...

The burden of debt for Canadian dental students: part 1. Review of the literature.

PubMed

Matthew, Ian R; Walton, Joanne N; Dumaresq, Cheryl; Sudmant, Walter

2006-09-01

Debt among Canadian university graduates is increasing, while money apportioned to federal and provincial needs-based student assistance programs has been decreasing since the 1990s. Dental students have had to absorb increased tuition fees at both the undergraduate and post-baccalaureate levels. Existing debt and high tuition fees may adversely influence a potential candidate"s decision to enroll in dental school. Likewise, debt incurred during the minimum 2 years of pre-dental education adds to the future debt load of dental graduates. It seems that few dental students can remain debt-free during their dental education, although data are lacking about the extent of debt among dental students and its impact on their career decisions. Government statistics focus primarily on tuition costs for baccalaureate-degree students. Tuition and clinic-related fees constitute a significant proportion of costs for dental students; moreover, university administrations perceive dentistry as an expensive curriculum. This first article of a 4-part series examines debt among dental students, both nationally and internationally.

Endangered Species. Management Improvements Could Enhance Recovery Program. Report to the Chairman, Subcommittee on Fisheries and Wildlife Conservation and the Environment, Committee on Merchant Marine and Fisheries, House of Representatives.

ERIC Educational Resources Information Center

General Accounting Office, Washington, DC. Resources, Community, and Economic Development Div.

Extinction of animal and plant species has become a serious problem that threatens to become more acute in coming years. The endangered species program was established to prevent further extinctions and ultimately recover species designated as threatened or endangered through the development and implementation of species recovery plans. Concerned…

Papers presented to the Conference on Large Body Impacts and Terrestrial Evolution: Geological, Climatological, and Biological Implications

NASA Technical Reports Server (NTRS)

1981-01-01

The effects of large impacts on the environment are discussed and include thermal effects, atmospheric effects, changes in ocean temperatures, and geomagnetic anomalies. Biological factors such as extinction and increases in mutation development were investigated. Geological anomalies studied include stratigraphic gaps, extinction of entire boundary layers from the geological record, and geochemical oddities. Evidence was examined for impact cratering throughout the world.

Severest crisis overlooked—Worst disruption of terrestrial environments postdates the Permian–Triassic mass extinction

PubMed Central

Hochuli, Peter A.; Sanson-Barrera, Anna; Schneebeli-Hermann, Elke; Bucher, Hugo

2016-01-01

Generally Early Triassic floras are believed to be depauperate, suffering from protracted recovery following the Permian–Triassic extinction event. Here we present palynological data of an expanded East Greenland section documenting recovered floras in the basal Triassic (Griesbachian) and a subsequent fundamental floral turnover, postdating the Permian–Triassic boundary extinction by about 500 kyrs. This event is marked by a swap in dominating floral elements, changing from gymnosperm pollen-dominated associations in the Griesbachian to lycopsid spore-dominated assemblages in the Dienerian. This turnover coincides with an extreme δ13Corg negative shift revealing a severe environmental crisis, probably induced by volcanic outbursts of the Siberian Traps, accompanied by a climatic turnover, changing from cool and dry in the Griesbachian to hot and humid in the Dienerian. Estimates of sedimentation rates suggest that this environmental alteration took place within some 1000 years. Similar, coeval changes documented on the North Indian Margin (Pakistan) and the Bowen Basin (Australia) indicate the global extent of this crisis. Our results evidence the first profound disruption of the recovery of terrestrial environments about 500kyrs after the Permian–Triassic extinction event. It was followed by another crisis, about 1myrs later thus, the Early Triassic can be characterised as a time of successive environmental crises. PMID:27340926

The scaling of population persistence with carrying capacity does not asymptote in populations of a fish experiencing extreme climate variability.

PubMed

White, Richard S A; Wintle, Brendan A; McHugh, Peter A; Booker, Douglas J; McIntosh, Angus R

2017-06-14

Despite growing concerns regarding increasing frequency of extreme climate events and declining population sizes, the influence of environmental stochasticity on the relationship between population carrying capacity and time-to-extinction has received little empirical attention. While time-to-extinction increases exponentially with carrying capacity in constant environments, theoretical models suggest increasing environmental stochasticity causes asymptotic scaling, thus making minimum viable carrying capacity vastly uncertain in variable environments. Using empirical estimates of environmental stochasticity in fish metapopulations, we showed that increasing environmental stochasticity resulting from extreme droughts was insufficient to create asymptotic scaling of time-to-extinction with carrying capacity in local populations as predicted by theory. Local time-to-extinction increased with carrying capacity due to declining sensitivity to demographic stochasticity, and the slope of this relationship declined significantly as environmental stochasticity increased. However, recent 1 in 25 yr extreme droughts were insufficient to extirpate populations with large carrying capacity. Consequently, large populations may be more resilient to environmental stochasticity than previously thought. The lack of carrying capacity-related asymptotes in persistence under extreme climate variability reveals how small populations affected by habitat loss or overharvesting, may be disproportionately threatened by increases in extreme climate events with global warming. © 2017 The Author(s).

Estimating the probability of an extinction or major outbreak for an environmentally transmitted infectious disease.

PubMed

Lahodny, G E; Gautam, R; Ivanek, R

2015-01-01

Indirect transmission through the environment, pathogen shedding by infectious hosts, replication of free-living pathogens within the environment, and environmental decontamination are suspected to play important roles in the spread and control of environmentally transmitted infectious diseases. To account for these factors, the classic Susceptible-Infectious-Recovered-Susceptible epidemic model is modified to include a compartment representing the amount of free-living pathogen within the environment. The model accounts for host demography, direct and indirect transmission, replication of free-living pathogens in the environment, and removal of free-living pathogens by natural death or environmental decontamination. Based on the assumptions of the deterministic model, a continuous-time Markov chain model is developed. An estimate for the probability of disease extinction or a major outbreak is obtained by approximating the Markov chain with a multitype branching process. Numerical simulations illustrate important differences between the deterministic and stochastic counterparts, relevant for outbreak prevention, that depend on indirect transmission, pathogen shedding by infectious hosts, replication of free-living pathogens, and environmental decontamination. The probability of a major outbreak is computed for salmonellosis in a herd of dairy cattle as well as cholera in a human population. An explicit expression for the probability of disease extinction or a major outbreak in terms of the model parameters is obtained for systems with no direct transmission or replication of free-living pathogens.

The effect of education debt on dentists' career decisions.

PubMed

Nicholson, Sean; Vujicic, Marko; Wanchek, Tanya; Ziebert, Anthony; Menezes, Adriana

2015-11-01

The purpose of the study was to determine whether there is an association between the amount of education debt on completing dental school (initial debt) and certain career decisions. The authors surveyed 1,842 practicing dentists who completed dental school between 1996 and 2011 to ascertain their initial education debt, the balance on their debt in 2013, and a variety of specialization and practice decisions made during their careers. Data also included demographic characteristics and parental income and education levels. Dentists with higher initial debt were less likely to specialize and more likely to enter private practice, accept high-paying jobs on graduation, and work longer hours. Choice of employment setting, practice ownership, and whether to provide Medicaid and charity care were associated with dentists' sexes and races but not debt. High debt levels influenced some career decisions, but the magnitude of these effects was small compared with the effects of demographic characteristics, including race and sex, on career choices. Policy makers concerned about the influence of student debt on the professional decisions of dental school graduates should recognize that students' demographic characteristics may be more powerful in driving career choices. Copyright © 2015 American Dental Association. Published by Elsevier Inc. All rights reserved.

Theoretical Study of Effect of Introducing π-Conjugation on Efficiency of Dye-Sensitized Solar Cell.

PubMed

Lee, Geon Hyeong; Kim, Young Sik

2018-09-01

In this study, phenoxazine (PXZ)-based dye sensitizers with triphenylamine (TPA) as a dual-electron donor and thiophen and benzothiadiazole (BTD) or 4,7-diethynylbenzo[c][1,2,5]thiadiazole (DEBT) as an electron acceptor (dye1, dye2, and dye3) were designed and investigated. dye3 can significantly stabilize the lowest unoccupied molecular orbital (LUMO) energy level of an organic dye. We used density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations to better understand the factors responsible for the photovoltaic performance. The absorption spectrum of the dyes showed different forms because of the different energy levels of the molecular orbital (MO) of each dye and the intramolecular energy transfer (EnT). Among the three dyes, dye3 showed greater red-shift, broader absorption spectra, and higher molar extinction coefficient. These results indicate that adding a withdrawing unit and π-conjugation to a dye can result in good photovoltaic properties for dye-sensitized solar cells (DSSCs).

Open-path, closed-path and reconstructed aerosol extinction at a rural site.

PubMed

Gordon, Timothy D; Prenni, Anthony J; Renfro, James R; McClure, Ethan; Hicks, Bill; Onasch, Timothy B; Freedman, Andrew; McMeeking, Gavin R; Chen, Ping

2018-04-09

The Handix Scientific Open-Path Cavity Ringdown Spectrometer (OPCRDS) was deployed during summer 2016 in Great Smoky Mountains National Park (GRSM). Extinction coefficients from the relatively new OPCRDS and from a more well-established extinction instrument agreed to within 7%. Aerosol hygroscopic growth (f(RH)) was calculated from the ratio of ambient extinction measured by the OPCRDS to dry extinction measured by a closed-path extinction monitor (Aerodyne's Cavity Attenuated Phase Shift Particulate Matter Extinction Monitor, CAPS PMex). Derived hygroscopicity (RH < 95%) from this campaign agreed with data from 1995 at the same site and time of year, which is noteworthy given the decreasing trend for organics and sulfate in the eastern U.S. However, maximum f(RH) values in 1995 were less than half as large as those recorded in 2016-possibly due to nephelometer truncation losses in 1995. Two hygroscopicity parameterizations were investigated using high time resolution OPCRDS+CAPS PMex data, and the K ext model was more accurate than the γ model. Data from the two ambient optical instruments, the OPCRDS and the open-path nephelometer, generally agreed; however, significant discrepancies between ambient scattering and extinction were observed, apparently driven by a combination of hygroscopic growth effects, which tend to increase nephelometer truncation losses and decrease sensitivity to the wavelength difference between the two instruments as a function of particle size. There was not a statistically significant difference in the mean reconstructed extinction values obtained from the original and the revised IMPROVE (Interagency Monitoring of Protected Visual Environments) equations. On average IMPROVE reconstructed extinction was ~25% lower than extinction measured by the OPCRDS, which suggests that the IMPROVE equations and 24-hr aerosol data are moderately successful in estimating current haze levels at GRSM. However, this conclusion is limited by the coarse temporal resolution and the low dynamic range of the IMPROVE reconstructed extinction.

7 CFR 1956.109 - General requirements for debt settlement.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 14 2010-01-01 2009-01-01 true General requirements for debt settlement. 1956.109 Section 1956.109 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING... and Business Programs § 1956.109 General requirements for debt settlement. (a) Debt due and payable...

20 CFR 422.306 - Report of overdue administrative debts to credit reporting agencies.

Code of Federal Regulations, 2010 CFR

2010-04-01

..., status, and history of the debt; (4) The debtor has the right to a complete explanation of the debt; (5...; (6) The debtor may request a review of the debt by giving us evidence showing that he or she does not...

76 FR 1063 - Modifications of Debt Instruments

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-07

... modified instrument received in an exchange will be classified as debt for Federal income tax purposes... properly classified as debt for Federal income tax purposes. Effective/Applicability Date The regulations... right that is not debt for federal income tax purposes. Paragraph (g) of this section contains examples...

41 CFR 105-56.014 - Purpose and scope.

Code of Federal Regulations, 2010 CFR

2010-07-01

... centralized salary offset computer matching, identify Federal employees who owe delinquent non-tax debt to the... satisfy delinquent non-tax debt owed to the United States. GSA will pursue, when appropriate, such debt... (FMS) administrative offset program, to collect delinquent debts owed to the Federal Government. This...

5 CFR 845.205 - Collection of debts.

Code of Federal Regulations, 2010 CFR

2010-01-01

... interest of the United States. (c) Collection in installments. (1) Whenever feasible, debts will be... an offset would substantially prejudice the Government's ability to collect the debt; and the time... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Collection of debts. 845.205 Section 845...

77 FR 62312 - Debt Management Advisory Committee; Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-12

... DEPARTMENT OF THE TREASURY Debt Management Advisory Committee; Meeting Notice is hereby given... Pennsylvania Avenue NW.,Washington, DC, on October 30, 2012 at 11:30 a.m. of the following debt management... advice has been offered by debt management advisory committees established by the several major segments...

Latin American Debt: Opportunities for Universities.

ERIC Educational Resources Information Center

Garg, Ramesh C.

The debt crisis of the lesser developed countries (LDCs) may provide opportunities for educational institutions. Through debt-for-education programs, a part of the huge debt load can be channelled into financing various educational programs sponsored by U.S. higher education institutions. Private commercial banks and multinational corporations are…

26 CFR 1.1286-2 - Stripped inflation-protected debt instruments.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 26 Internal Revenue 11 2013-04-01 2013-04-01 false Stripped inflation-protected debt instruments... Losses § 1.1286-2 Stripped inflation-protected debt instruments. Stripped inflation-protected debt instruments. If a Treasury Inflation-Protected Security is stripped under the Department of the Treasury's...

26 CFR 1.1286-2 - Stripped inflation-protected debt instruments.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 26 Internal Revenue 11 2014-04-01 2014-04-01 false Stripped inflation-protected debt instruments... Losses § 1.1286-2 Stripped inflation-protected debt instruments. Stripped inflation-protected debt instruments. If a Treasury Inflation-Protected Security is stripped under the Department of the Treasury's...

Marine extinction risk shaped by trait-environment interactions over 500 million years.

PubMed

Orzechowski, Emily A; Lockwood, Rowan; Byrnes, Jarrett E K; Anderson, Sean C; Finnegan, Seth; Finkel, Zoe V; Harnik, Paul G; Lindberg, David R; Liow, Lee Hsiang; Lotze, Heike K; McClain, Craig R; McGuire, Jenny L; O'Dea, Aaron; Pandolfi, John M; Simpson, Carl; Tittensor, Derek P

2015-10-01

Perhaps the most pressing issue in predicting biotic responses to present and future global change is understanding how environmental factors shape the relationship between ecological traits and extinction risk. The fossil record provides millions of years of insight into how extinction selectivity (i.e., differential extinction risk) is shaped by interactions between ecological traits and environmental conditions. Numerous paleontological studies have examined trait-based extinction selectivity; however, the extent to which these patterns are shaped by environmental conditions is poorly understood due to a lack of quantitative synthesis across studies. We conducted a meta-analysis of published studies on fossil marine bivalves and gastropods that span 458 million years to uncover how global environmental and geochemical changes covary with trait-based extinction selectivity. We focused on geographic range size and life habit (i.e., infaunal vs. epifaunal), two of the most important and commonly examined predictors of extinction selectivity. We used geochemical proxies related to global climate, as well as indicators of ocean acidification, to infer average global environmental conditions. Life-habit selectivity is weakly dependent on environmental conditions, with infaunal species relatively buffered from extinction during warmer climate states. In contrast, the odds of taxa with broad geographic ranges surviving an extinction (>2500 km for genera, >500 km for species) are on average three times greater than narrow-ranging taxa (estimate of odds ratio: 2.8, 95% confidence interval = 2.3-3.5), regardless of the prevailing global environmental conditions. The environmental independence of geographic range size extinction selectivity emphasizes the critical role of geographic range size in setting conservation priorities. © 2015 John Wiley & Sons Ltd.

Breeding Young as a Survival Strategy during Earth’s Greatest Mass Extinction

NASA Astrophysics Data System (ADS)

Botha-Brink, Jennifer; Codron, Daryl; Huttenlocker, Adam K.; Angielczyk, Kenneth D.; Ruta, Marcello

2016-04-01

Studies of the effects of mass extinctions on ancient ecosystems have focused on changes in taxic diversity, morphological disparity, abundance, behaviour and resource availability as key determinants of group survival. Crucially, the contribution of life history traits to survival during terrestrial mass extinctions has not been investigated, despite the critical role of such traits for population viability. We use bone microstructure and body size data to investigate the palaeoecological implications of changes in life history strategies in the therapsid forerunners of mammals before and after the Permo-Triassic Mass Extinction (PTME), the most catastrophic crisis in Phanerozoic history. Our results are consistent with truncated development, shortened life expectancies, elevated mortality rates and higher extinction risks amongst post-extinction species. Various simulations of ecological dynamics indicate that an earlier onset of reproduction leading to shortened generation times could explain the persistence of therapsids in the unpredictable, resource-limited Early Triassic environments, and help explain observed body size distributions of some disaster taxa (e.g., Lystrosaurus). Our study accounts for differential survival in mammal ancestors after the PTME and provides a methodological framework for quantifying survival strategies in other vertebrates during major biotic crises.

Gamma-Ray Burst Afterglows as Probes of Environment and Blastwave Physics. 1; Absorption by Host Galaxy Gas and Dust

NASA Technical Reports Server (NTRS)

Starling, R. L. C.; Wijers, R. A. M. J.; Wiersema, K.; Rol, E.; Curran, P. A.; Kouveliotou, C.; vanderHorst, A. J.; Heemskerk, M. H. M.

2006-01-01

We use a new approach to obtain limits on the absorbing columns towards an initial sample of 10 long Gamma-Ray Bursts observed with BeppoSAX and selected on the basis of their good optical and nIR coverage, from simultaneous fits to nIR, optical and X-ray afterglow data, in count space and including the effects of metallicity. In no cases is a MIV-like ext,inction preferred, when testing MW, LMC and SMC extinction laws. The 2175A bump would in principle be detectable in all these afterglows, but is not present in the data. An SMC-like gas-to-dust ratio or lower value can be ruled out for 4 of the hosts analysed here (assuming Sh4C metallicity and extinction law) whilst the remainder of the sample have too large an error to discriminate. We provide a more accurate estimate of the line-of-sight extinction and improve upon the uncertainties for the majority of the extinction measurements made in previous studies of this sample. We discuss this method to determine extinction values in comparison with the most commonly employed existing methods.

Breeding Young as a Survival Strategy during Earth's Greatest Mass Extinction.

PubMed

Botha-Brink, Jennifer; Codron, Daryl; Huttenlocker, Adam K; Angielczyk, Kenneth D; Ruta, Marcello

2016-04-05

Studies of the effects of mass extinctions on ancient ecosystems have focused on changes in taxic diversity, morphological disparity, abundance, behaviour and resource availability as key determinants of group survival. Crucially, the contribution of life history traits to survival during terrestrial mass extinctions has not been investigated, despite the critical role of such traits for population viability. We use bone microstructure and body size data to investigate the palaeoecological implications of changes in life history strategies in the therapsid forerunners of mammals before and after the Permo-Triassic Mass Extinction (PTME), the most catastrophic crisis in Phanerozoic history. Our results are consistent with truncated development, shortened life expectancies, elevated mortality rates and higher extinction risks amongst post-extinction species. Various simulations of ecological dynamics indicate that an earlier onset of reproduction leading to shortened generation times could explain the persistence of therapsids in the unpredictable, resource-limited Early Triassic environments, and help explain observed body size distributions of some disaster taxa (e.g., Lystrosaurus). Our study accounts for differential survival in mammal ancestors after the PTME and provides a methodological framework for quantifying survival strategies in other vertebrates during major biotic crises.

An Application of Robust Method in Multiple Linear Regression Model toward Credit Card Debt

NASA Astrophysics Data System (ADS)

Amira Azmi, Nur; Saifullah Rusiman, Mohd; Khalid, Kamil; Roslan, Rozaini; Sufahani, Suliadi; Mohamad, Mahathir; Salleh, Rohayu Mohd; Hamzah, Nur Shamsidah Amir

2018-04-01

Credit card is a convenient alternative replaced cash or cheque, and it is essential component for electronic and internet commerce. In this study, the researchers attempt to determine the relationship and significance variables between credit card debt and demographic variables such as age, household income, education level, years with current employer, years at current address, debt to income ratio and other debt. The provided data covers 850 customers information. There are three methods that applied to the credit card debt data which are multiple linear regression (MLR) models, MLR models with least quartile difference (LQD) method and MLR models with mean absolute deviation method. After comparing among three methods, it is found that MLR model with LQD method became the best model with the lowest value of mean square error (MSE). According to the final model, it shows that the years with current employer, years at current address, household income in thousands and debt to income ratio are positively associated with the amount of credit debt. Meanwhile variables for age, level of education and other debt are negatively associated with amount of credit debt. This study may serve as a reference for the bank company by using robust methods, so that they could better understand their options and choice that is best aligned with their goals for inference regarding to the credit card debt.

Analysis of 2011 physician assistant education debt load.

PubMed

Moore, Miranda A; Coffman, Megan; Cawley, James F; Crowley, Diana; Miller, Anthony; Klink, Kathleen

2017-03-01

This study seeks to investigate how physician assistants (PAs) finance their education and to characterize the educational debt of PA students. Data from the 2011 American Academy of PAs (AAPA)-Physician Assistant Education Association Graduating Student Survey were used to explore the educational debt of PA students. The median total educational debt of a PA student graduating in 2011 was $80,000. Little financial assistance, other than student loans, is available to PA students. Eighty-five percent of PA students report owing some PA education debt amount, with 23% owing at least $100,000. This study provides a baseline look at PA student debt loads as a starting point for more detailed and robust research into new graduate specialty choices and PA career migration into other specialties. Further research is needed to explore the effect of student debt on students' specialty choices.

Can't afford a baby? Debt and young Americans.

PubMed

Nau, Michael; Dwyer, Rachel E; Hodson, Randy

2015-12-01

This article explores the role of personal debt in the transition to parenthood. We analyze data from the National Longitudinal Study of Youth-1997 cohort and find that for the generation coming of age in the 2000s, student loans delay fertility for women, particularly at very high levels of debt. Home mortgages and credit card debt, in contrast, appear to be precursors to parenthood. These results indicate that different forms of debt have different implications for early adulthood transitions: whereas consumer loans or home mortgages immediately increase access to consumption goods, there is often a significant delay between the accrual and realization of benefits for student loans. The double-edged nature of debt as both barrier and facilitator to life transitions highlights the importance of looking at debt both as a monetary issue and also as a carrier of social meanings.

The High Price of Debt: Household financial debt and its impact on mental and physical health

PubMed Central

Nandi, Arijit; Adam, Emma; McDade, Thomas

2013-01-01

Household financial debt in America has risen dramatically in recent years. While there is evidence that debt is associated with adverse psychological health, its relationship with other health outcomes is relatively unknown. We investigate the associations of multiple indices of financial debt with psychological and general health outcomes among 8400 young adult respondents from the National Longitudinal Study of Adolescent Health (Add Health). Our findings show that reporting high financial debt relative to available assets is associated with higher perceived stress and depression, worse selfreported general health, and higher diastolic blood pressure. These associations remain significant when controlling for prior socioeconomic status, psychological and physical health, and other demographic factors. The results suggest that debt is an important socioeconomic determinant of health that should be explored further in social epidemiology research. PMID:23849243

The Color of Debt: Racial Disparities in Anticipated Medical Student Debt in the United States

PubMed Central

Dugger, Robert A.; El-Sayed, Abdulrahman M.; Dogra, Anjali; Messina, Catherine; Bronson, Richard; Galea, Sandro

2013-01-01

Context The cost of American medical education has increased substantially over the past decade. Given racial/ethnic inequalities in access to financial resources, it is plausible that increases in student debt burden resulting from these increases in cost may not be borne equally. Objective To evaluate racial/ethnic disparities in medical student debt. Design, Setting, and Participants Authors collected self-reported data from a non-representative sample of 2414 medical students enrolled at 111/159 accredited US medical schools between December 1st 2010 and March 27th 2011. After weighting for representativeness by race and class year and calculating crude anticipated debt by racial/ethnic category, authors fit multivariable regression models of debt by race/ethnicity adjusted for potential confounders. Main Outcome Measures Anticipated educational debt upon graduation greater than $150,000. Results 62.1% of medical students anticipated debt in excess of $150,000 upon graduation. The proportion of Blacks, Whites, Hispanics, and Asians reporting anticipated educational debt in excess of $150,000 was 77.3%, 65.1%, 57.2% and 50.2%, respectively. Both Black and White medical students demonstrated a significantly higher likelihood of anticipated debt in excess of $150,000 when compared to Asians [Blacks (OR = 2.7, 1.3–5.6), Whites (OR = 1.7, 1.3–2.2)] in adjusted models. Conclusion Black medical students had significantly higher anticipated debt than Asian students. This finding has implications for understanding differential enrollment among minority groups in US medical schools. PMID:24019975

Extinction risk and eco-evolutionary dynamics in a variable environment with increasing frequency of extreme events.

PubMed

Vincenzi, Simone

2014-08-06

One of the most dramatic consequences of climate change will be the intensification and increased frequency of extreme events. I used numerical simulations to understand and predict the consequences of directional trend (i.e. mean state) and increased variability of a climate variable (e.g. temperature), increased probability of occurrence of point extreme events (e.g. floods), selection pressure and effect size of mutations on a quantitative trait determining individual fitness, as well as the their effects on the population and genetic dynamics of a population of moderate size. The interaction among climate trend, variability and probability of point extremes had a minor effect on risk of extinction, time to extinction and distribution of the trait after accounting for their independent effects. The survival chances of a population strongly and linearly decreased with increasing strength of selection, as well as with increasing climate trend and variability. Mutation amplitude had no effects on extinction risk, time to extinction or genetic adaptation to the new climate. Climate trend and strength of selection largely determined the shift of the mean phenotype in the population. The extinction or persistence of the populations in an 'extinction window' of 10 years was well predicted by a simple model including mean population size and mean genetic variance over a 10-year time frame preceding the 'extinction window', although genetic variance had a smaller role than population size in predicting contemporary risk of extinction. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Droplet Combustion Experiments Aboard the International Space Station

NASA Astrophysics Data System (ADS)

Dietrich, Daniel L.; Nayagam, Vedha; Hicks, Michael C.; Ferkul, Paul V.; Dryer, Frederick L.; Farouk, Tanvir; Shaw, Benjamin D.; Suh, Hyun Kyu; Choi, Mun Y.; Liu, Yu Cheng; Avedisian, C. Thomas; Williams, Forman A.

2014-10-01

This paper summarizes the first results from isolated droplet combustion experiments performed on the International Space Station (ISS). The long durations of microgravity provided in the ISS enable the measurement of droplet and flame histories over an unprecedented range of conditions. The first experiments were with heptane and methanol as fuels, initial droplet droplet diameters between 1.5 and 5.0 m m, ambient oxygen mole fractions between 0.1 and 0.4, ambient pressures between 0.7 and 3.0 a t m and ambient environments containing oxygen and nitrogen diluted with both carbon dioxide and helium. The experiments show both radiative and diffusive extinction. For both fuels, the flames exhibited pre-extinction flame oscillations during radiative extinction with a frequency of approximately 1 H z. The results revealed that as the ambient oxygen mole fraction was reduced, the diffusive-extinction droplet diameter increased and the radiative-extinction droplet diameter decreased. In between these two limiting extinction conditions, quasi-steady combustion was observed. Another important measurement that is related to spacecraft fire safety is the limiting oxygen index (LOI), the oxygen concentration below which quasi-steady combustion cannot be supported. This is also the ambient oxygen mole fraction for which the radiative and diffusive extinction diameters become equal. For oxygen/nitrogen mixtures, the LOI is 0.12 and 0.15 for methanol and heptane, respectively. The LOI increases to approximately 0.14 (0.14 O 2/0.56 N 2/0.30 C O 2) and 0.17 (0.17 O 2/0.63 N 2/0.20 C O 2) for methanol and heptane, respectively, for ambient environments that simulated dispersing an inert-gas suppressant (carbon dioxide) into a nominally air (1.0 a t m) ambient environment. The LOI is approximately 0.14 and 0.15 for methanol and heptane, respectively, when helium is dispersed into air at 1 atm. The experiments also showed unique burning behavior for large heptane droplets. After the visible hot flame radiatively extinguished around a large heptane droplet, the droplet continued to burn with a cool flame. This phenomena was observed repeatably over a wide range of ambient conditions. These cool flames were invisible to the experiment imaging system but their behavior was inferred by the sustained quasi-steady burning after visible flame extinction. Verification of this new burning regime was established by both theoretical and numerical analysis of the experimental results. These innovative experiments have provided a wealth of new data for improving the understanding of droplet combustion and related aspects of fire safety, as well as offering important measurements that can be used to test sophisticated evolving computational models and theories of droplet combustion.

24 CFR 811.108 - Debt service reserve.

Code of Federal Regulations, 2011 CFR

2011-04-01

... funding of the debt service reserve. Any excess investment income shall be added to the debt service reserve. In the event such investment income is insufficient, surplus cash or residual receipts, to the... the owner's debt service payment. Any excess investment income shall be added to and become part of...

Yes, No, Maybe So: College Students' Attitudes Regarding Debt

ERIC Educational Resources Information Center

Zerquera, Desiree D.; McGowan, Brian L.; Ferguson, Tomika L.

2016-01-01

We examined college student attitudes regarding debt. Based on focus group interviews with 31 students from 4 different institutions within a Midwestern university system, data analysis yielded a continuum that captures students' debt approaches while enrolled in college. Findings indicate that students avoided debt completely, made intentional…

7 CFR 1956.112 - Debts ineligible for settlement.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 14 2010-01-01 2009-01-01 true Debts ineligible for settlement. 1956.112 Section 1956.112 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL... § 1956.112 Debts ineligible for settlement. Debts will not be settled: (a) If referral to the Office of...

7 CFR 1956.75 - Chargeoff.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 14 2010-01-01 2009-01-01 true Chargeoff. 1956.75 Section 1956.75 Agriculture... REGULATIONS (CONTINUED) DEBT SETTLEMENT Debt Settlement-Farm Loan Programs and Multi-Family Housing § 1956.75 Chargeoff. (a) Judgment debts. Subject to the provisions of § 1956.57(g)(3), judgment debts may be charged...

26 CFR 1.1286-2 - Stripped inflation-indexed debt instruments.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 11 2010-04-01 2010-04-01 true Stripped inflation-indexed debt instruments. 1....1286-2 Stripped inflation-indexed debt instruments. Stripped inflation-indexed debt instruments. If a Treasury Inflation-Indexed Security is stripped under the Department of the Treasury's Separate Trading of...

76 FR 64429 - Senior Executive Service; Public Debt Performance Review Board (PRB)

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-18

... DEPARTMENT OF THE TREASURY Bureau of the Public Debt Senior Executive Service; Public Debt Performance Review Board (PRB) AGENCY: Bureau of the Public Debt, Treasury. ACTION: Notice of Members of... reviews the performance appraisals of career senior executives who are below the level of Assistant...

29 CFR 1650.202 - Past-due legally enforceable debt.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 4 2010-07-01 2010-07-01 false Past-due legally enforceable debt. 1650.202 Section 1650.202 Labor Regulations Relating to Labor (Continued) EQUAL EMPLOYMENT OPPORTUNITY COMMISSION DEBT COLLECTION Procedures for the Collection of Debts by Federal Tax Refund Offset § 1650.202 Past-due legally...

49 CFR 89.31 - Use of professional debt collection agencies.

Code of Federal Regulations, 2010 CFR

2010-10-01

... agencies except for those debts owed by State and local governments, other Federal agencies, current... 49 Transportation 1 2010-10-01 2010-10-01 false Use of professional debt collection agencies. 89... FEDERAL CLAIMS COLLECTION ACT Collection of Claims § 89.31 Use of professional debt collection agencies...

42 CFR 413.89 - Bad debts, charity, and courtesy allowances.

Code of Federal Regulations, 2013 CFR

2013-10-01

... SERVICES; OPTIONAL PROSPECTIVELY DETERMINED PAYMENT RATES FOR SKILLED NURSING FACILITIES Specific... allowable costs. (e) Criteria for allowable bad debt. A bad debt must meet the following criteria to be... amount of allowable bad debt (as defined in paragraph (e) of this section) is reduced: (i) For cost...

42 CFR 413.89 - Bad debts, charity, and courtesy allowances.

Code of Federal Regulations, 2014 CFR

2014-10-01

... SERVICES; OPTIONAL PROSPECTIVELY DETERMINED PAYMENT RATES FOR SKILLED NURSING FACILITIES Specific... allowable costs. (e) Criteria for allowable bad debt. A bad debt must meet the following criteria to be... amount of allowable bad debt (as defined in paragraph (e) of this section) is reduced: (i) For cost...

7 CFR 3555.151 - Eligibility requirements.

Code of Federal Regulations, 2014 CFR

2014-01-01

... and total debt (TD) ratio, to determine adequate repayment for the requested loan. The Agency reserves... and the monthly amount of PITI plus recurring monthly debts (total debt) does not exceed 41 percent of... obligations specifically excluded by State law, the debts of non-purchasing spouse must be included in the...

76 FR 78085 - Permissible Investments for Federal and State Savings Associations: Corporate Debt Securities

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-15

... Part 362 Permissible Investments for Federal and State Savings Associations: Corporate Debt Securities... association from acquiring and retaining a corporate debt security unless it determines, prior to acquiring... whether a corporate debt security is eligible for investment under this proposed rule. DATES: Comments...

26 CFR 1.1275-6 - Integration of qualifying debt instruments.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 11 2010-04-01 2010-04-01 true Integration of qualifying debt instruments. 1....1275-6 Integration of qualifying debt instruments. (a) In general. This section generally provides for the integration of a qualifying debt instrument with a hedge or combination of hedges if the combined...

75 FR 42662 - Debt Collection

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-22

... a tax overpayment payable to a taxpayer by the amount of past-due, legally enforceable debt owed by... collection of non-tax debts owed to PBGC. This proposed rule would add salary offset and administrative wage... other laws applicable to the collection of non-tax debt owed to the Government. Background In 1994, PBGC...

Addressing Student Debt in the Classroom

ERIC Educational Resources Information Center

Perkins, David; Johnston, Tim; Lytle, Rick

2016-01-01

Student debt is a national concern. The authors address debt in the classroom to enhance students' understanding of the consequences of debt and the need for caution when financing their education. However, student feedback indicates this understanding has a delayed effect on borrowing behavior and underscores the importance of making difficult…

77 FR 22390 - Debt Management Advisory Committee Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-13

... DEPARTMENT OF THE TREASURY Debt Management Advisory Committee Meeting Notice is hereby given... Pennsylvania Avenue NW., Washington, DC, on May 1, 2012 at 11:30 a.m. of the following debt management advisory... advice has been offered by debt management advisory committees established by the several major segments...

Cumulative Student Loan Debt in Minnesota, 2015

ERIC Educational Resources Information Center

Williams-Wyche, Shaun

2016-01-01

To better understand student debt in Minnesota, the Minnesota Office of Higher Education (the Office) gathers information on cumulative student loan debt from Minnesota degree-granting institutions. These data detail the number of students with loans by institution, the cumulative student loan debt incurred at that institution, and the percentage…

75 FR 19873 - Collection of Administrative Debts; Collection of Debts Arising From Enforcement and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-16

...The Federal Election Commission (``Commission'') is promulgating rules implementing statutory provisions regarding the collection of debts owed to the United States Government. The Commission is also integrating its rules regarding the collection of debts arising solely from the Administrative Fines program into the new rules.

76 FR 24406 - Collection by Offset From Indebted Government Employees

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-02

... proposed regulations to eliminate the 10-year statute of limitations on collection of debt by... eliminate the 10-year statute of limitations on collection of debt by administrative offset, which includes... offset to collect a debt without time limitations on debt outstanding after the Government's right to...

Pilot Study of Debt Elasticity

ERIC Educational Resources Information Center

Greiner, Keith; Girardi, Tony

2006-01-01

This report examines the relationship between student loan debt and the manner in which that debt is described. It focuses on three forms of description: (1) monthly payments, (2) total debt, and (3) income after graduation. The authors used the term elasticity to describe the relationship between consumers' college choices and the retention…

Iraq’s Debt Relief: Procedure and Potential Implications for International Debt Relief

DTIC Science & Technology

2009-01-26

countries use different interest rates and levy different penalties for Iraq’s payment arrears . Hence, the debt owed to each creditor can grow at...REPORT DATE 26 JAN 2009 2. REPORT TYPE 3. DATES COVERED 00-00-2009 to 00-00-2009 4. TITLE AND SUBTITLE Iraq’s Debt Relief: Procedure and...Potential Implications for International Debt Relief 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e

Radiative Extinction of Gaseous Spherical Diffusion Flames in Microgravity

NASA Technical Reports Server (NTRS)

Santa, K. J.; Chao, B. H.; Sunderland, P. B.; Urban, D. L.; Stocker, D. P.; Axelbaum, R. L.

2007-01-01

Radiative extinction of spherical diffusion flames was investigated experimentally and numerically. The experiments involved microgravity spherical diffusion flames burning ethylene and propane at 0.98 bar. Both normal (fuel flowing into oxidizer) and inverse (oxidizer flowing into fuel) flames were studied, with nitrogen supplied to either the fuel or the oxygen. Flame conditions were chosen to ensure that the flames extinguished within the 2.2 s of available test time; thus extinction occurred during unsteady flame conditions. Diagnostics included color video and thin-filament pyrometry. The computations, which simulated flow from a porous sphere into a quiescent environment, included detailed chemistry, transport and radiation, and yielded transient results. Radiative extinction was observed experimentally and simulated numerically. Extinction time, peak temperature, and radiative loss fraction were found to be independent of flow rate except at very low flow rates. Radiative heat loss was dominated by the combustion products downstream of the flame and was found to scale with flame surface area, not volume. For large transient flames the heat release rate also scaled with surface area and thus the radiative loss fraction was largely independent of flow rate. Peak temperatures at extinction onset were about 1100 K, which is significantly lower than for kinetic extinction. One observation of this work is that while radiative heat losses can drive transient extinction, this is not because radiative losses are increasing with time (flame size) but rather because the heat release rate is falling off as the temperature drops.

What Do We Know About the Ultraviolet Extinction Curve, Fifty Years After the Discovery of the Bump?

NASA Astrophysics Data System (ADS)

Clayton, Geoffrey C.

2012-05-01

It is almost 50 years since Ted Stecher reported the discovery of the 2175 A bump, and almost 25 years since CCM characterized the UV extinction curve as a one-parameter function of R(V), the ratio of total-to-selective extinction. Great strides have been made since then in laboratory, theory, and observation but many questions still remain. The bump is still an unidentified feature, and CCM is not a reliable guide to the wavelength dependence of dust extinction beyond the Milky Way. In fact, the average extinction curve of SMC dust, which has little or no evidence for a 2175 A bump, may be more common in extragalactic environments than Milky Way type dust. The UV extinction curve has been extended to the Lyman limit without any sign in a turnover in the far-UV rise. The old standbys, silicates, graphite, amorphous carbon, and PAH's are still the go-to grain types. But many questions remain about how global properties such as metallicity may lead to large variations in the extinction properties from one galaxy to another. Also of great interest is how dust grains are created, evolve and are destroyed, and in particular, what fraction comes from sources such as evolved stars and supernovae, and what fraction is grown in the ISM. I plan to summarize the role of laboratory and theory can play in better understanding the interstellar dust grains responsible UV extinction.

Indebtedness of dental school graduates in Canada: mortgaged futures.

PubMed

McDermott, R E; Fuglerud, K P

1996-03-01

The debt level of graduating dental students is increasing annually. Six of Canada's 10 dental schools responded to a survey designed to ascertain the level of student debt on entering and graduating from dental school. For the academic year 1993-94, the average starting debt for students was $2,013.89 and the average graduating debt was $25,671.30. On average, dental students accumulated more than $23,600 in debt while pursuing their dental education. Of those students who completed the survey, 57.89 per cent relied on their parents for assistance, and 76.69 per cent received student/government loans. The level of student debt was independent of age, gender and parents' income.

Testing the role of external debt in environmental degradation: empirical evidence from Turkey.

PubMed

Katircioglu, Salih; Celebi, Aysem

2018-03-01

This study investigates the role of external debt stock in Turkey, which has suffered from heavy (external and domestic) debt stock for many years. Annual data from 1960 to 2013 was analyzed using time series analysis in order to study this. The results confirm the validity of the conventional environmental Kuznets curve (EKC) in the case of Turkey. However, this study also found that Turkey's external debt stock did not influence the Turkish economy's long-term EKC behavior. Fortunately, the results suggest that there are important interactions among external debt stock, CO 2 emissions, energy consumption, and real income; that is, changes in external debt volume precede changes in these aggregates' volumes.

An Empirical Study of Self-Perceived Employability: Improving the Prospects for Student Employment Success in an Uncertain Environment

ERIC Educational Resources Information Center

Qenani, Eivis; MacDougall, Neal; Sexton, Carol

2014-01-01

Employability of graduates has taken more prominence in recent years due to the bleak economic situation, the impact of student debt, and an increasingly competitive global labor market. Given the substantial individual and public investment made in higher education, it is particularly important that graduates are employable upon graduation. The…

Genomics of Extinct and Endangered Species (2011 JGI User Meeting)

ScienceCinema

Shuster, Stephen

2018-02-13

The U.S. Department of Energy Joint Genome Institute (JGI) invited scientists interested in the application of genomics to bioenergy and environmental issues, as well as all current and prospective users and collaborators, to attend the annual DOE JGI Genomics of Energy & Environment Meeting held March 22-24, 2011 in Walnut Creek, Calif. The emphasis of this meeting was on the genomics of renewable energy strategies, carbon cycling, environmental gene discovery, and engineering of fuel-producing organisms. The meeting features presentations by leading scientists advancing these topics. Stephen Shuster of Penn State University gives a presentation on "Genomics of Extinct and Endangered Species" at the 6th annual Genomics of Energy & Environment Meeting on March 23, 2011.

Stochastic resonance and noise delayed extinction in a model of two competing species

NASA Astrophysics Data System (ADS)

Valenti, D.; Fiasconaro, A.; Spagnolo, B.

2004-01-01

We study the role of the noise in the dynamics of two competing species. We consider generalized Lotka-Volterra equations in the presence of a multiplicative noise, which models the interaction between the species and the environment. The interaction parameter between the species is a random process which obeys a stochastic differential equation with a generalized bistable potential in the presence of a periodic driving term, which accounts for the environment temperature variation. We find noise-induced periodic oscillations of the species concentrations and stochastic resonance phenomenon. We find also a nonmonotonic behavior of the mean extinction time of one of the two competing species as a function of the additive noise intensity.

Leveraging Psychological Insights to Encourage the Responsible Use of Consumer Debt.

PubMed

Hershfield, Hal E; Sussman, Abigail B; O'Brien, Rourke L; Bryan, Christopher J

2015-11-01

U.S. consumers currently hold $880 billion in revolving debt, with a mean household credit card balance of approximately $6,000. Although economic factors play a role in this societal issue, it is clear that psychological forces also affect consumers' decisions to take on and maintain unmanageable debt balances. We examine three psychological barriers to the responsible use of credit and debt. We discuss the tendency for consumers to (a) make erroneous predictions about future spending habits, (b) rely too heavily on values presented on billing statements, and (c) categorize debt and saving into separate mental accounts. To overcome these obstacles, we urge policymakers to implement methods that facilitate better budgeting of future expenses, modify existing credit card statement disclosures, and allow consumers to easily apply government transfers (such as tax credits) to debt repayment. In doing so, we highlight minimal and inexpensive ways to remedy the debt problem. © The Author(s) 2015.

Can't afford a baby? Debt and young Americans☆

PubMed Central

Nau, Michael; Dwyer, Rachel E.; Hodson, Randy

2016-01-01

This article explores the role of personal debt in the transition to parenthood. We analyze data from the National Longitudinal Study of Youth-1997 cohort and find that for the generation coming of age in the 2000s, student loans delay fertility for women, particularly at very high levels of debt. Home mortgages and credit card debt, in contrast, appear to be precursors to parenthood. These results indicate that different forms of debt have different implications for early adulthood transitions: whereas consumer loans or home mortgages immediately increase access to consumption goods, there is often a significant delay between the accrual and realization of benefits for student loans. The double-edged nature of debt as both barrier and facilitator to life transitions highlights the importance of looking at debt both as a monetary issue and also as a carrier of social meanings. PMID:28090131

The high price of debt: household financial debt and its impact on mental and physical health.

PubMed

Sweet, Elizabeth; Nandi, Arijit; Adam, Emma K; McDade, Thomas W

2013-08-01

Household financial debt in America has risen dramatically in recent years. While there is evidence that debt is associated with adverse psychological health, its relationship with other health outcomes is relatively unknown. We investigate the associations of multiple indices of financial debt with psychological and general health outcomes among 8400 young adult respondents from the National Longitudinal Study of Adolescent Health (Add Health). Our findings show that reporting high financial debt relative to available assets is associated with higher perceived stress and depression, worse self-reported general health, and higher diastolic blood pressure. These associations remain significant when controlling for prior socioeconomic status, psychological and physical health, and other demographic factors. The results suggest that debt is an important socioeconomic determinant of health that should be explored further in social epidemiology research. Copyright © 2013 Elsevier Ltd. All rights reserved.

Debt, cohabitation, and marriage in young adulthood.

PubMed

Addo, Fenaba R

2014-10-01

Despite growing evidence that debt influences pivotal life events in early and young adulthood, the role of debt in the familial lives of young adults has received relatively little attention. Using data from the NLSY 1997 cohort (N = 6,749) and a discrete-time competing risks hazard model framework, I test whether the transition to first union is influenced by a young adult's credit card and education loan debt above and beyond traditional educational and labor market characteristics. I find that credit card debt is positively associated with cohabitation for men and women, and that women with education loan debt are more likely than women without such debt to delay marriage and transition into cohabitation. Single life may be difficult to afford, but marital life is un-affordable as well. Cohabitation presents an alternative to single life, but not necessarily a marital substitute for these young adults.

Influence of the Cold Buster (Trademark) Sports Bar on Heat Debt, Mobilization and Oxidation of Energy Substrates,

DTIC Science & Technology

1992-12-01

Limmer , 1983; Vallerand et al., 1992a, 1992b). -22- Without the information provided by the heat balance, it is very difficult to try to explain the...nonuniform thermal environments between 18 and 30 0C. Aviat Space Environ Med 60: 558- 565, 1989. Livingstone SD, Grayson J, Frim J, Allen CL & Limmer RE...caffeine mixture in humans. J App! Physic! 67(1): 438-444, 1989a. 0 Vallerand AL, Limmer R and Schmegner IF. Computer acquisition and analysis of skin

42 CFR 413.89 - Bad debts, charity, and courtesy allowances.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 2 2010-10-01 2010-10-01 false Bad debts, charity, and courtesy allowances. 413.89... Categories of Costs § 413.89 Bad debts, charity, and courtesy allowances. Link to an amendment published at 75 FR 49198, Aug. 12, 2010. (a) Principle. Bad debts, charity, and courtesy allowances are deductions...

14 CFR § 1261.412 - Interest, penalties, and administrative costs.

Code of Federal Regulations, 2014 CFR

2014-01-01

...—that is, a bill is mailed before the debt is actually owed—it can include the required interest... debt—that is, the additional costs incurred in processing and handling the debt because it became... from the date that the debt became delinquent. (f) When a debt is paid in partial or installment...

77 FR 76148 - Self-Regulatory Organizations; NYSE Arca, Inc.; Notice of Filing of Proposed Rule Change To List...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-26

..., corporate debt securities are fixed-income securities issued by businesses to finance their operations... consist of both foreign and domestic debt instruments, including corporate bonds, high yield bonds... stated above, the Fund may invest in a variety of debt securities, including corporate debt securities...

5 CFR 835.606 - Change in notification to Internal Revenue Service.

Code of Federal Regulations, 2010 CFR

2010-01-01

... (CONTINUED) CIVIL SERVICE REGULATIONS (CONTINUED) DEBT COLLECTION Collection of Debts by Federal Tax Refund...) of this section, after OPM sends IRS notification of an individual's liability for a debt, OPM will... payment to the account of the debtor named in the notification that reduces the amount of the debt...

7 CFR 1782.20 - Debt Settlement.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Collection Improvement Act of 1996. This law provides that any non-tax debt or claim owed to the United... 7 Agriculture 12 2010-01-01 2010-01-01 false Debt Settlement. 1782.20 Section 1782.20 Agriculture... (CONTINUED) SERVICING OF WATER AND WASTE PROGRAMS § 1782.20 Debt Settlement. Pursuant to 7 U.S.C. 1981, this...

31 CFR 29.501 - Purpose; incorporation by reference; scope.

Code of Federal Regulations, 2010 CFR

2010-07-01

... CFR 900.3. (2) Tax debts. This subpart does not apply to tax debts. (d)(1) Sections 29.501 through 29... BENEFIT PAYMENTS UNDER CERTAIN DISTRICT OF COLUMBIA RETIREMENT PROGRAMS Debt Collection and Waivers of... debts due the United States. (b) The regulations of this subpart incorporate by this reference all...

5 CFR 835.603 - Notification of intent to collect.

Code of Federal Regulations, 2010 CFR

2010-01-01

... REGULATIONS (CONTINUED) DEBT COLLECTION Collection of Debts by Federal Tax Refund Offset § 835.603... by IRS tax refund offset (Notice of Intent) will state: (1) The amount of the debt; (2) That unless... debt by requesting the IRS to reduce any amounts payable to the debtor as a Federal income tax refund...

45 CFR 32.1 - Purpose and scope.

Code of Federal Regulations, 2010 CFR

2010-10-01

... satisfy delinquent non-tax debts owed to the United States. (b) Authority. These standards and procedures... Regional Offices that administer a program that gives rise to a delinquent non-tax debt owed to the United... payments to satisfy delinquent non-tax debt owed to the United States. The Department may pursue such debt...

41 CFR 105-57.001 - Purpose, authority and scope.

Code of Federal Regulations, 2010 CFR

2010-07-01

... administrative wage garnishment to satisfy delinquent non-tax debt owed to the United States. (b) These standards... non-tax debt owed to the United States and that pursues recovery of such debt. (2) This part will..., including the offset of Federal payments to satisfy delinquent non-tax debt owed to the United States. GSA...

29 CFR 4903.33 - Referral of debt for tax refund offset.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 9 2010-07-01 2010-07-01 false Referral of debt for tax refund offset. 4903.33 Section... AND ADMINISTRATIVE RULES AND PROCEDURES DEBT COLLECTION Tax Refund Offset § 4903.33 Referral of debt for tax refund offset. The Director of the Financial Operations Department (or a department official...

75 FR 69151 - Small Business Jobs Act: 504 Loan Program Debt Refinancing

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-10

... SMALL BUSINESS ADMINISTRATION Small Business Jobs Act: 504 Loan Program Debt Refinancing AGENCY: U... regarding the Small Business Jobs Act: 504 Loan Program Debt Refinancing. The meeting will be open to the... the 504 Loan Program Debt Refinancing established by Sec. 1122 of the Small Business Jobs Act (Pub. L...

7 CFR 3.12 - Reporting of consumer debts.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 1 2010-01-01 2010-01-01 false Reporting of consumer debts. 3.12 Section 3.12... and Compromise of Claims § 3.12 Reporting of consumer debts. (a) Notice. In demand letters to debtors... the delinquent consumer debt to credit reporting agencies after 60 days; (2) The specific information...

7 CFR 792.3 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... debts and claims. The late payment interest rate shall be determined as of the date a debt becomes... debt owed the Government, or any agency thereof. FSA means the Farm Service Agency of the United States..., data file, or similar record of debts owed to FSA, CCC, or any other Government Agency with respect to...

Tough Choices in Tough Times: Debt and Medication Nonadherence

ERIC Educational Resources Information Center

Kalousova, Lucie; Burgard, Sarah A.

2014-01-01

Debt is a ubiquitous component of households' financial portfolios. Yet we have scant understanding of how household debt constrains spending on needed health care. Diverse types of debt have different financial properties and recent work has shown that they may have varying implications for spending on needed health care. In this article, we…

22 CFR 512.10 - Collection by administrative offset.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Government's right to collect the debt first accrued, unless facts material to the Government's right were... to: Debts owed by any State or local Government; debts arising under or payments made under the... the Government's ability to collect the debt, and the time before the payment is to be made does not...

5 CFR 550.1106 - Time limit on collection of debts.

Code of Federal Regulations, 2010 CFR

2010-01-01

... to collect a debt more than 10 years after the Government's right to collect the debt first accrued... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Time limit on collection of debts. 550... PAY ADMINISTRATION (GENERAL) Collection by Offset From Indebted Government Employees § 550.1106 Time...

26 CFR 1.1275-6 - Integration of qualifying debt instruments.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 26 Internal Revenue 11 2012-04-01 2012-04-01 false Integration of qualifying debt instruments. 1... Losses § 1.1275-6 Integration of qualifying debt instruments. (a) In general. This section generally provides for the integration of a qualifying debt instrument with a hedge or combination of hedges if the...

26 CFR 1.1275-6 - Integration of qualifying debt instruments.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 26 Internal Revenue 11 2013-04-01 2013-04-01 false Integration of qualifying debt instruments. 1... Losses § 1.1275-6 Integration of qualifying debt instruments. (a) In general. This section generally provides for the integration of a qualifying debt instrument with a hedge or combination of hedges if the...

26 CFR 1.1275-6 - Integration of qualifying debt instruments.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 26 Internal Revenue 11 2014-04-01 2014-04-01 false Integration of qualifying debt instruments. 1... Losses § 1.1275-6 Integration of qualifying debt instruments. (a) In general. This section generally provides for the integration of a qualifying debt instrument with a hedge or combination of hedges if the...

26 CFR 1.1275-6 - Integration of qualifying debt instruments.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 26 Internal Revenue 11 2011-04-01 2011-04-01 false Integration of qualifying debt instruments. 1... Losses § 1.1275-6 Integration of qualifying debt instruments. (a) In general. This section generally provides for the integration of a qualifying debt instrument with a hedge or combination of hedges if the...

31 CFR 5.9 - When will Treasury entities transfer a Treasury debt to the Treasury Department's Financial...

Code of Federal Regulations, 2010 CFR

2010-07-01

... a Treasury debt to the Treasury Department's Financial Management Service for collection? 5.9... Treasury Department's Financial Management Service for collection? (a) Treasury entities will transfer any eligible debt that is more than 180 days delinquent to the Financial Management Service for debt collection...

42 CFR 413.178 - Bad debts.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 2 2010-10-01 2010-10-01 false Bad debts. 413.178 Section 413.178 Public Health...) Services and Organ Procurement Costs § 413.178 Bad debts. Link to an amendment published at 75 FR 49199, Aug. 12, 2010. (a) CMS will reimburse each facility its allowable Medicare bad debts, as defined in...

Towards a Rhythmanalysis of Debt Dressage: Education as Rhythmic Resistance in Everyday Indebted Life

ERIC Educational Resources Information Center

Wozniak, Jason Thomas

2017-01-01

Debt shapes subjectivity by rhythmically training indebted subjects. Stated slightly differently, there exists a debt dressage that produces indebted subjectivity. One of the principle aims of this article is to introduce rhythm into the debt analysis debates. Building on Henri Lefebvre's book "Rhythmanalysis: Space, Time and Everyday…

New England's Disadvantaged Populations Struggle the Most with Student Debt Repayment

ERIC Educational Resources Information Center

Saas, Darcy Rollins

2016-01-01

Regularly reported statistics about high and growing student-loan debt levels, combined with increased rates of delinquency and default, have prompted calls to address the student-debt "crisis." For New England, with its highly educated population and large higher education industry, student-loan debt is an important economic policy…

6 CFR 11.6 - Reporting debts.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 6 Domestic Security 1 2010-01-01 2010-01-01 false Reporting debts. 11.6 Section 11.6 Domestic Security DEPARTMENT OF HOMELAND SECURITY, OFFICE OF THE SECRETARY CLAIMS § 11.6 Reporting debts. DHS will report delinquent debts to credit bureaus and other automated databases in accordance with 31 U.S.C. 3711...

12 CFR 560.40 - Commercial paper and corporate debt securities.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 12 Banks and Banking 6 2014-01-01 2012-01-01 true Commercial paper and corporate debt securities... paper and corporate debt securities. Pursuant to HOLA section 5(c)(2)(D), a Federal savings association may invest in, sell, or hold commercial paper and corporate debt securities subject to the provisions...

12 CFR 160.40 - Commercial paper and corporate debt securities.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 12 Banks and Banking 1 2014-01-01 2014-01-01 false Commercial paper and corporate debt securities... LENDING AND INVESTMENT § 160.40 Commercial paper and corporate debt securities. Pursuant to HOLA section 5... investment in the commercial paper and corporate debt securities of any one issuer, or issued by any one...

12 CFR 560.40 - Commercial paper and corporate debt securities.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 12 Banks and Banking 6 2013-01-01 2012-01-01 true Commercial paper and corporate debt securities... paper and corporate debt securities. Pursuant to HOLA section 5(c)(2)(D), a Federal savings association may invest in, sell, or hold commercial paper and corporate debt securities subject to the provisions...

12 CFR 560.40 - Commercial paper and corporate debt securities.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Commercial paper and corporate debt securities... paper and corporate debt securities. Pursuant to HOLA section 5(c)(2)(D), a Federal savings association may invest in, sell, or hold commercial paper and corporate debt securities subject to the provisions...

12 CFR 560.40 - Commercial paper and corporate debt securities.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 12 Banks and Banking 6 2012-01-01 2012-01-01 false Commercial paper and corporate debt securities... paper and corporate debt securities. Pursuant to HOLA section 5(c)(2)(D), a Federal savings association may invest in, sell, or hold commercial paper and corporate debt securities subject to the provisions...

12 CFR 160.40 - Commercial paper and corporate debt securities.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 12 Banks and Banking 1 2013-01-01 2013-01-01 false Commercial paper and corporate debt securities... LENDING AND INVESTMENT § 160.40 Commercial paper and corporate debt securities. Pursuant to HOLA section 5... investment in the commercial paper and corporate debt securities of any one issuer, or issued by any one...

12 CFR 560.40 - Commercial paper and corporate debt securities.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 12 Banks and Banking 5 2011-01-01 2011-01-01 false Commercial paper and corporate debt securities... paper and corporate debt securities. Pursuant to HOLA section 5(c)(2)(D), a Federal savings association may invest in, sell, or hold commercial paper and corporate debt securities subject to the provisions...

Debt Change and Marital Satisfaction Change in Recently Married Couples

ERIC Educational Resources Information Center

Dew, Jeffrey

2008-01-01

Although recently married couples report debt as one of their top concerns, research has not measured how debt changes relate to changes in their marital satisfaction. Further, the mechanisms that link debt and marital satisfaction are unknown. Findings using the National Survey of Families and Households (N = 1,078 couples) demonstrated that…

Issues 2016: Is There a Student Debt Crisis?

ERIC Educational Resources Information Center

Eden, Max

2016-01-01

Student debt is a convenient target in a presidential election year, but it obscures the true crisis: high dropout rates from low-quality postsecondary institutions and the unmanageable debt borne by students of those institutions. And despite rising student debt, monthly loan payments as a share of income have remained steady, added earnings…

20 CFR 422.305 - Report of overdue program overpayment debts to consumer reporting agencies.

Code of Federal Regulations, 2010 CFR

2010-04-01

... debts to consumer reporting agencies. (a) Debts we will report. We will report to consumer reporting... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Report of overdue program overpayment debts to consumer reporting agencies. 422.305 Section 422.305 Employees' Benefits SOCIAL SECURITY...

75 FR 8274 - Collection of Administrative Debts; Collection of Debts Arising From Enforcement and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-24

...The Federal Election Commission (``Commission'') requests comments on proposed rules implementing statutory provisions regarding the collection of debts owed to the United States Government. The Commission also proposes integrating its rules regarding the collection of debts arising solely from the Administrative Fines program into the new proposed rules.

77 FR 65248 - Senior Executive Service; Public Debt Performance Review Board

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-25

... Performance Review Board AGENCY: Bureau of the Public Debt, Treasury. ACTION: Notice. SUMMARY: This notice announces the appointment of the members of the Public Debt Performance Review Board (PRB) for the Bureau of the Public Debt (BPD). The PRB reviews the performance appraisals of career senior executives who are...

12 CFR 225.140 - Disposition of property acquired in satisfaction of debts previously contracted.

Code of Federal Regulations, 2010 CFR

2010-01-01

... satisfaction of debts previously contracted. 225.140 Section 225.140 Banks and Banking FEDERAL RESERVE SYSTEM... property acquired in satisfaction of debts previously contracted. (a) The Board recently considered the... acquiring and holding assets acquired in satisfaction of a debt previously contracted in good faith (a “dpc...

12 CFR 1.7 - Securities held in satisfaction of debts previously contracted; holding period; disposal...

Code of Federal Regulations, 2010 CFR

2010-01-01

... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Securities held in satisfaction of debts... § 1.7 Securities held in satisfaction of debts previously contracted; holding period; disposal; accounting treatment; non-speculative purpose. (a) Securities held in satisfaction of debts previously...

7 CFR 3.12 - Reporting of consumer debts.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 1 2011-01-01 2011-01-01 false Reporting of consumer debts. 3.12 Section 3.12... and Compromise of Claims § 3.12 Reporting of consumer debts. (a) Notice. In demand letters to debtors... the delinquent consumer debt to credit reporting agencies after 60 days; (2) The specific information...

Scale-invariant properties of public-debt growth

NASA Astrophysics Data System (ADS)

Petersen, A. M.; Podobnik, B.; Horvatic, D.; Stanley, H. E.

2010-05-01

Public debt is one of the important economic variables that quantitatively describes a nation's economy. Because bankruptcy is a risk faced even by institutions as large as governments (e.g., Iceland), national debt should be strictly controlled with respect to national wealth. Also, the problem of eliminating extreme poverty in the world is closely connected to the study of extremely poor debtor nations. We analyze the time evolution of national public debt and find "convergence": initially less-indebted countries increase their debt more quickly than initially more-indebted countries. We also analyze the public debt-to-GDP ratio {\\cal R} , a proxy for default risk, and approximate the probability density function P({\\cal R}) with a Gamma distribution, which can be used to establish thresholds for sustainable debt. We also observe "convergence" in {\\cal R} : countries with initially small {\\cal R} increase their {\\cal R} more quickly than countries with initially large {\\cal R} . The scaling relationships for debt and {\\cal R} have practical applications, e.g. the Maastricht Treaty requires members of the European Monetary Union to maintain {\\cal R} < 0.6 .

Extinction phase transitions in a model of ecological and evolutionary dynamics

NASA Astrophysics Data System (ADS)

Barghathi, Hatem; Tackkett, Skye; Vojta, Thomas

2017-07-01

We study the non-equilibrium phase transition between survival and extinction of spatially extended biological populations using an agent-based model. We especially focus on the effects of global temporal fluctuations of the environmental conditions, i.e., temporal disorder. Using large-scale Monte-Carlo simulations of up to 3 × 107 organisms and 105 generations, we find the extinction transition in time-independent environments to be in the well-known directed percolation universality class. In contrast, temporal disorder leads to a highly unusual extinction transition characterized by logarithmically slow population decay and enormous fluctuations even for large populations. The simulations provide strong evidence for this transition to be of exotic infinite-noise type, as recently predicted by a renormalization group theory. The transition is accompanied by temporal Griffiths phases featuring a power-law dependence of the life time on the population size.

Personal Bankruptcy After Traumatic Brain or Spinal Cord Injury: The Role of Medical Debt

PubMed Central

Relyea-Chew, Annemarie; Hollingworth, William; Chan, Leighton; Comstock, Bryan A.; Overstreet, Karen A.; Jarvik, Jeffrey G.

2012-01-01

Objective To estimate the prevalence of medical debt among traumatic brain injury (TBI) and spinal cord injury (SCI) patients who discharged their debts through bankruptcy. Design A cross-sectional comparison of bankruptcy filings of injured versus randomly selected bankruptcy petitioners. Setting Patients hospitalized with SCI or TBI (1996–2002) and personal bankruptcy petitioners (2001–2004) in western Washington State. Participants Subjects (N=186) who filed for bankruptcy, comprised of 93 patients with previous SCI or TBI and 93 randomly selected bankruptcy petitioners. Interventions Not applicable. Main Outcome Measures Medical and nonmedical debt, assets, income, expenses, and employment recorded in the bankruptcy petition. Results Five percent of randomly selected petitioners and 26% of petitioners with TBI or SCI had substantial medical debt (debt that accounted for more than 20% of all unsecured debts). SCI and TBI petitioners had fewer assets and were more likely to be receiving government income assistance at the time of bankruptcy than controls. SCI and TBI patients with a higher blood alcohol content at injury were more likely to have substantial medical debts (odds ratio=2.70; 95% confidence interval, 1.04–7.00). Conclusions Medical debt plays an important role in some bankruptcies after TBI or SCI. We discuss policy options for reducing financial distress after serious injury. PMID:19254605

Personal bankruptcy after traumatic brain or spinal cord injury: the role of medical debt.

PubMed

Relyea-Chew, Annemarie; Hollingworth, William; Chan, Leighton; Comstock, Bryan A; Overstreet, Karen A; Jarvik, Jeffrey G

2009-03-01

To estimate the prevalence of medical debt among traumatic brain injury (TBI) and spinal cord injury (SCI) patients who discharged their debts through bankruptcy. A cross-sectional comparison of bankruptcy filings of injured versus randomly selected bankruptcy petitioners. Patients hospitalized with SCI or TBI (1996-2002) and personal bankruptcy petitioners (2001-2004) in western Washington State. Subjects (N=186) who filed for bankruptcy, comprised of 93 patients with previous SCI or TBI and 93 randomly selected bankruptcy petitioners. Not applicable. Medical and nonmedical debt, assets, income, expenses, and employment recorded in the bankruptcy petition. Five percent of randomly selected petitioners and 26% of petitioners with TBI or SCI had substantial medical debt (debt that accounted for more than 20% of all unsecured debts). SCI and TBI petitioners had fewer assets and were more likely to be receiving government income assistance at the time of bankruptcy than controls. SCI and TBI patients with a higher blood alcohol content at injury were more likely to have substantial medical debts (odds ratio=2.70; 95% confidence interval, 1.04-7.00). Medical debt plays an important role in some bankruptcies after TBI or SCI. We discuss policy options for reducing financial distress after serious injury.

A model of the demand for Islamic banks debt-based financing instrument

NASA Astrophysics Data System (ADS)

Jusoh, Mansor; Khalid, Norlin

2013-04-01

This paper presents a theoretical analysis of the demand for debt-based financing instruments of the Islamic banks. Debt-based financing, such as through baibithamanajil and al-murabahah, is by far the most prominent of the Islamic bank financing and yet it has been largely ignored in Islamic economics literature. Most studies instead have been focusing on equity-based financing of al-mudharabah and al-musyarakah. Islamic bank offers debt-based financing through various instruments derived under the principle of exchange (ukud al-mu'awadhat) or more specifically, the contract of deferred sale. Under such arrangement, Islamic debt is created when goods are purchased and the payments are deferred. Thus, unlike debt of the conventional bank which is a form of financial loan contract to facilitate demand for liquid assets, this Islamic debt is created in response to the demand to purchase goods by deferred payment. In this paper we set an analytical framework that is based on an infinitely lived representative agent model (ILRA model) to analyze the demand for goods to be purchased by deferred payment. The resulting demand will then be used to derive the demand for Islamic debt. We also investigate theoretically, factors that may have an impact on the demand for Islamic debt.

Demographic and service-use profiles of individuals using the CarePayment program for hospital-related medical debt: results from a nationwide survey of guarantors.

PubMed

Lessard, Laura; Solomon, Julie

2016-07-15

Many Americans find themselves with problems paying medical bills, and medical debt can lead to numerous negative financial, social and access to healthcare outcomes. One potential market-based solution to these challenges is to provide financing options that have patient-friendly terms while complying with increasingly complex federal lending regulations. CarePayment (CP) is one entity that provides zero interest financing to individuals from participating medical facilities. An independent, initial outcome study was undertaken to understand the demographic and medical debt-related outcomes of CP users. This information is integral to understanding whether and how this program can ameliorate the negative consequences of medical debt. A nationwide telephone survey was conducted with a random sample of 8122 guarantors who were paying off CarePayment debt as of January 1, 2015. Respondents were asked about their demographic characteristics as well as self-report of negative outcomes typically associated with medical debt. Analyses included descriptive statistics along with logistic regression models comparing first-time CP users and those with higher amounts of CP debt to others. The most commonly reported financial challenge related to medical bills was problems paying or being unable to pay medical bills (59.5 %). The most commonly reported access-to-care challenges were skipping a medical test or treatment recommended by a doctor (32.9 %) and having a medical problem but not going to the doctor/clinic (30.3 %). Comparisons between first-time and repeat CP users suggest that first-time users were significantly more likely to report several negative outcomes and those with both CP and non-CP debt were significantly more likely to report nearly all of the undesirable financial and access outcomes that were assessed compared to those with only CP debt. The results suggest that CP use, especially repeat CP use, may be associated with a reduction in many negative outcomes of medical debt. In addition, while we found that individuals with only CP debt fared better than those with both CP debt and other medical debt, 60 % of our sample had more than one source of medical debt. This suggests that the beneficial impact of CP could be increased by expanding access to the program.

Cool-flame Extinction During N-Alkane Droplet Combustion in Microgravity

NASA Technical Reports Server (NTRS)

Nayagam, Vedha; Dietrich, Daniel L.; Hicks, Michael C.; Williams, Forman A.

2014-01-01

Recent droplet combustion experiments onboard the International Space Station (ISS) have revealed that large n-alkane droplets can continue to burn quasi-steadily following radiative extinction in a low-temperature regime, characterized by negative-temperaturecoefficient (NTC) chemistry. In this study we report experimental observations of n-heptane, n-octane, and n-decane droplets of varying initial sizes burning in oxygen/nitrogen/carbon dioxide and oxygen/helium/nitrogen environments at 1.0, 0.7, and 0.5 atmospheric pressures. The oxygen concentration in these tests varied in the range of 14% to 25% by volume. Large n-alkane droplets exhibited quasi-steady low-temperature burning and extinction following radiative extinction of the visible flame while smaller droplets burned to completion or disruptively extinguished. A vapor-cloud formed in most cases slightly prior to or following the "cool flame" extinction. Results for droplet burning rates in both the hot-flame and cool-flame regimes as well as droplet extinction diameters at the end of each stage are presented. Time histories of radiant emission from the droplet captured using broadband radiometers are also presented. Remarkably the "cool flame" extinction diameters for all the three n-alkanes follow a trend reminiscent of the ignition delay times observed in previous studies. The similarities and differences among the n-alkanes during "cool flame" combustion are discussed using simplified theoretical models of the phenomenon

Global deep-sea extinctions during the Pleistocene ice ages

NASA Astrophysics Data System (ADS)

Hayward, Bruce W.

2001-07-01

The dark, near-freezing environment of the deep oceans is regarded as one of the most stable habitats on Earth, and this stability is generally reflected in the slow turnover rates (extinctions and appearances) of the organisms that live there. By far the best fossil record of deep-sea organisms is provided by the shells of benthic foraminifera (Protista). A little-known global extinction of deep-sea benthic foraminifera occurred during the Pleistocene ice ages. In the southwest Pacific, it caused the disappearance of at least two families, 15 genera, and 48 species (˜15% 25% of the fauna) of dominantly uniserial, elongate foraminifera with distinctive apertural modifications. These forms progressively died back and became extinct during glacial periods in the late Pliocene to middle Pleistocene (ca. 2.5 0.6 Ma); most extinctions occurred between 1.0 and 0.6 Ma, at the time of the middle Pleistocene climatic revolution. This first high-resolution study of this extinction event indicates that it was far more significant for deep-sea diversity loss than previously reported (10 species). The middle Pleistocene extinction was the most dramatic last phase of a worldwide decline in the abundance of these elongate forms, a phase that began during cooling near the Eocene-Oligocene boundary and continued during the middle Miocene. Clearly these taxa declined when the world cooled, but the reason is yet to be resolved.

Rarity and extinction risk in coral reef angelfishes on isolated islands: interrelationships among abundance, geographic range size and specialisation

NASA Astrophysics Data System (ADS)

Hobbs, Jean-Paul A.; Jones, G. P.; Munday, P. L.

2010-03-01

Determining the species most vulnerable to increasing degradation of coral reef habitats requires identification of the ecological traits that increase extinction risk. In the terrestrial environment, endemic species often face a high risk of extinction because of an association among three traits that threaten species persistence: small geographic range size, low abundance and ecological specialisation. To test whether these traits are associated in coral reef fishes, this study compared abundance and specialisation in endemic and widespread angelfishes at the remote Christmas and Cocos Islands in the Indian Ocean. The interrelationships among traits conferring high extinction risk in terrestrial communities did not apply to these fishes. Endemic angelfishes were 50-80 times more abundant than widespread species at these islands. Furthermore, there was no relationship between abundance and ecological specialisation. Endemic species were not more specialised than widespread congeners and endemics used similar resources to many widespread species. Three widespread species exhibited low abundance and some degree of specialisation, which may expose them to a greater risk of local extinction. For endemic species, high abundance and lack of specialisation on susceptible habitats may compensate for the global extinction risk posed by having extremely small geographic ranges. However, recent extinctions of small range reef fishes confirm that endemics are not immune to the increasing severity of large-scale disturbances that can affect species throughout their geographic range.

Student Debt Crisis: Are Students Incurring Excessive Debt? Program Report 85-13.

ERIC Educational Resources Information Center

Hansen, W. Lee; Rhodes, Marilyn S.

Definitions of manageable college student debts are discussed and one definition is applied to California data, using the Student Expenses and Resources Survey. Definitions proposed by Daniere, Hartman, and Horch define manageable debt levels in terms of future income. A comparison of the three proposals shows the number of years of repayment…

12 CFR 16.6 - Sales of nonconvertible debt.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Sales of nonconvertible debt. 16.6 Section 16.6... RULES § 16.6 Sales of nonconvertible debt. (a) The OCC will deem offers or sales of bank issued... grade; (5) Prior to or simultaneously with the sale of the debt, each purchaser receives an offering...

Development and External Debt: Friend or Foe? Academy for Educational Development 25th Anniversary Seminar Series.

ERIC Educational Resources Information Center

Hope, Nicholas C.

Arguing that the benefits from borrowing abroad exceed the costs recently imposed on countries through debt-servicing difficulties, this paper defines debt as an engine of growth, forcing the borrower to produce goods efficiently, export them, and function competitively in the international market. Debt-servicing difficulties of developing nations…

15 CFR 19.7 - When will Commerce entities compromise a Commerce debt?

Code of Federal Regulations, 2012 CFR

2012-01-01

... 15 Commerce and Foreign Trade 1 2012-01-01 2012-01-01 false When will Commerce entities compromise a Commerce debt? 19.7 Section 19.7 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.7 When will Commerce entities compromise...

15 CFR 19.15 - How will Commerce entities refer Commerce debts to private collection agencies?

Code of Federal Regulations, 2010 CFR

2010-01-01

... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false How will Commerce entities refer Commerce debts to private collection agencies? 19.15 Section 19.15 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.15 How will...

15 CFR 19.15 - How will Commerce entities refer Commerce debts to private collection agencies?

Code of Federal Regulations, 2014 CFR

2014-01-01

... 15 Commerce and Foreign Trade 1 2014-01-01 2014-01-01 false How will Commerce entities refer Commerce debts to private collection agencies? 19.15 Section 19.15 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.15 How will...

15 CFR 19.15 - How will Commerce entities refer Commerce debts to private collection agencies?

Code of Federal Regulations, 2012 CFR

2012-01-01

... 15 Commerce and Foreign Trade 1 2012-01-01 2012-01-01 false How will Commerce entities refer Commerce debts to private collection agencies? 19.15 Section 19.15 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.15 How will...

15 CFR 19.7 - When will Commerce entities compromise a Commerce debt?

Code of Federal Regulations, 2011 CFR

2011-01-01

... 15 Commerce and Foreign Trade 1 2011-01-01 2011-01-01 false When will Commerce entities compromise a Commerce debt? 19.7 Section 19.7 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.7 When will Commerce entities compromise...

15 CFR 19.15 - How will Commerce entities refer Commerce debts to private collection agencies?

Code of Federal Regulations, 2011 CFR

2011-01-01

... 15 Commerce and Foreign Trade 1 2011-01-01 2011-01-01 false How will Commerce entities refer Commerce debts to private collection agencies? 19.15 Section 19.15 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.15 How will...

15 CFR 19.7 - When will Commerce entities compromise a Commerce debt?

Code of Federal Regulations, 2010 CFR

2010-01-01

... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false When will Commerce entities compromise a Commerce debt? 19.7 Section 19.7 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.7 When will Commerce entities compromise...

15 CFR 19.15 - How will Commerce entities refer Commerce debts to private collection agencies?

Code of Federal Regulations, 2013 CFR

2013-01-01

... 15 Commerce and Foreign Trade 1 2013-01-01 2013-01-01 false How will Commerce entities refer Commerce debts to private collection agencies? 19.15 Section 19.15 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.15 How will...

15 CFR 19.7 - When will Commerce entities compromise a Commerce debt?

Code of Federal Regulations, 2013 CFR

2013-01-01

... 15 Commerce and Foreign Trade 1 2013-01-01 2013-01-01 false When will Commerce entities compromise a Commerce debt? 19.7 Section 19.7 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.7 When will Commerce entities compromise...

15 CFR 19.7 - When will Commerce entities compromise a Commerce debt?

Code of Federal Regulations, 2014 CFR

2014-01-01

... 15 Commerce and Foreign Trade 1 2014-01-01 2014-01-01 false When will Commerce entities compromise a Commerce debt? 19.7 Section 19.7 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.7 When will Commerce entities compromise...

26 CFR 1.593-5 - Addition to reserves for bad debts.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 7 2010-04-01 2010-04-01 true Addition to reserves for bad debts. 1.593-5... bad debts. (a) Amount of addition. As an alternative to a deduction from gross income under section... a deduction under section 166(c) for a reasonable addition to a reserve for bad debts. In the case...

7 CFR 792.15 - Prior provision of rights with respect to debt.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 7 2010-01-01 2010-01-01 false Prior provision of rights with respect to debt. 792.15..., DEPARTMENT OF AGRICULTURE PROVISIONS COMMON TO MORE THAN ONE PROGRAM DEBT SETTLEMENT POLICIES AND PROCEDURES § 792.15 Prior provision of rights with respect to debt. FSA will not provide an administrative appeal...

12 CFR 16.6 - Sales of nonconvertible debt.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 12 Banks and Banking 1 2013-01-01 2013-01-01 false Sales of nonconvertible debt. 16.6 Section 16.6... RULES § 16.6 Sales of nonconvertible debt. (a) The OCC will deem offers or sales of bank issued...) Prior to or simultaneously with the sale of the debt, each purchaser receives an offering document that...

12 CFR 16.6 - Sales of nonconvertible debt.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 12 Banks and Banking 1 2011-01-01 2011-01-01 false Sales of nonconvertible debt. 16.6 Section 16.6... RULES § 16.6 Sales of nonconvertible debt. (a) The OCC will deem offers or sales of bank issued... grade; (5) Prior to or simultaneously with the sale of the debt, each purchaser receives an offering...

Debt-Repaying Mechanism in Chinese Relationships: An Exploration of the Folk Concepts of "Pao" and Human Emotional Debt.

ERIC Educational Resources Information Center

Chang, Hui-Ching; Holt, G. Richard

1994-01-01

Explores the mechanisms of "pao" and human emotional debt underlying Chinese human relationships through interviews with 55 Chinese in Taiwan. The definition, recompensation, minimization, and manipulation of human emotional debt and the linguistic code by which relations can be made closer or more distant following the principles of…

45 CFR 2506.41 - What are the Corporation's procedures for collecting debts by tax refund offset?

Code of Federal Regulations, 2010 CFR

2010-10-01

... collecting debts by tax refund offset? 2506.41 Section 2506.41 Public Welfare Regulations Relating to Public Welfare (Continued) CORPORATION FOR NATIONAL AND COMMUNITY SERVICE COLLECTION OF DEBTS Tax Refund Offset § 2506.41 What are the Corporation's procedures for collecting debts by tax refund offset? (a) The...

10 CFR 1015.405 - Discharge of indebtedness; reporting requirements.

Code of Federal Regulations, 2010 CFR

2010-01-01

.... (b) 31 U.S.C. 3711(i) requires DOE to sell a delinquent non-tax debt upon termination of collection... indebtedness; reporting requirements. (a) Before discharging a delinquent debt (also referred to as a close out of the debt), DOE shall take all appropriate steps to collect the debt in accordance with 31 U.S.C...

17 CFR 204.76 - Use of credit bureau or consumer reporting agencies.

Code of Federal Regulations, 2010 CFR

2010-04-01

... interest that will accrue on the debt, that all costs incurred to collect the debt will be charged to the... EXCHANGE COMMISSION RULES RELATING TO DEBT COLLECTION Miscellaneous: Credit Bureau Reporting, Collection... delinquent debts to consumer reporting agencies (See 31 U.S.C. 3701(a)(3), 3711). Sixty days prior to release...

5 CFR 845.403 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... EMPLOYEES RETIREMENT SYSTEM-DEBT COLLECTION Agency Requests to OPM for Recovery of a Debt From the Civil... Act of 1966 as amended by the Debt Collection Act of 1982 and implemented by 4 CFR 101.1 et seq., the... Fund to satisfy a debt to the United States under 31 U.S.C. 3716. Agency means— (a) An Executive agency...

7 CFR 1403.9 - Late payment interest and administrative charges.

Code of Federal Regulations, 2010 CFR

2010-01-01

... apply: (i) To debts owed by Federal agencies and State and local governments. Interest on debts owed by... the rate of interest charged by the U.S. Treasury for funds borrowed by CCC on the day the debt became... shall be expressed as an annual rate of interest which CCC charges on delinquent debts. The late payment...

Should the Public Pay for Higher Education? Equality, Liberty, and Educational Debt

ERIC Educational Resources Information Center

Martin, Christopher

2017-01-01

As governments shift costs from the public to students, a higher education has become synonymous with educational debt. Liberal egalitarians have justified educational debt on the grounds that it facilitates socioeconomic equality. On this view, the public should only fund access for those students who are so poorly off that educational debt would…

7 CFR 1951.136 - Procedures for Department of Treasury offset and cross-servicing for the Rural Housing Service...

Code of Federal Regulations, 2010 CFR

2010-01-01

...-Servicing (Cross-Servicing) Program, which centralizes all Government debt collection actions. A borrower... debts which are over 180 days delinquent to the Secretary of the Treasury for collection by centralized... the debt is reported to Treasury. The notice will include: (1) The nature and amount of the debt, the...

Playing the Numbers: The Best Bad Option

ERIC Educational Resources Information Center

Doyle, William R.

2012-01-01

College graduates and current students are swimming in a sea of debt. As of this writing, the total amount of outstanding student loan debt has been estimated at $960 billion. The Occupy Student Debt movement, inspired by Occupy Wall Street, has suggested that all student loan debt should be forgiven. As a starting point, members of the movement…

78 FR 54568 - Debt That Is a Position in Personal Property That Is Part of a Straddle

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-05

... regarding when an issuer's obligation under a debt instrument may be a position in actively traded personal... actively traded.'' A debt or obligation generally is not property of the debtor or obligor. Nevertheless... is denominated in a nonfunctional currency, the obligor's position under the debt obligation is a...

Relationships between College Students' Credit Card Debt, Undesirable Academic Behaviors and Cognitions, and Academic Performance

ERIC Educational Resources Information Center

Hogan, Eileen A.; Bryant, Sarah K.; Overymyer-Day, Leslie E.

2013-01-01

The acquisition of credit card debt by college students has long been a topic of concern. This study explores relationships among debt, undesirable academic behaviors and cognitions, and academic performance, through surveys of 338 students in a public university, replicating two past measures of credit card debt and creating new measures of…

Transparency in State Debt Disclosure. Working Papers. No. 17-10

ERIC Educational Resources Information Center

Zhao, Bo; Wang, Wen

2017-01-01

We develop a new measure of relative debt transparency by comparing the amount of state debt reported in the annual Census survey and the amount reported in the statistical section of the state Comprehensive Annual Financial Report (CAFR). GASB 44 requires states to start reporting their total debt in the CAFR statistical section in FY 2006.…

29 CFR 4903.31 - Eligibility of debt for tax refund offset.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 4903.31 Labor Regulations Relating to Labor (Continued) PENSION BENEFIT GUARANTY CORPORATION INTERNAL...) If the debt is a consumer debt and exceeds $100, the PBGC has disclosed the debt to a consumer reporting agency (as authorized by 31 U.S.C. 3711(f) and provided in § 4903.32), unless a consumer reporting...

13 CFR 120.975 - CDC Liquidation of loans and debt collection litigation.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 13 Business Credit and Assistance 1 2014-01-01 2014-01-01 false CDC Liquidation of loans and debt... BUSINESS LOANS Development Company Loan Program (504) Authority of Cdcs to Perform Liquidation and Debt Collection Litigation § 120.975 CDC Liquidation of loans and debt collection litigation. (a) PCLP CDCs. If a...

13 CFR 120.975 - CDC Liquidation of loans and debt collection litigation.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false CDC Liquidation of loans and debt... BUSINESS LOANS Development Company Loan Program (504) Authority of Cdcs to Perform Liquidation and Debt Collection Litigation § 120.975 CDC Liquidation of loans and debt collection litigation. (a) PCLP CDCs. If a...

13 CFR 120.975 - CDC Liquidation of loans and debt collection litigation.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 13 Business Credit and Assistance 1 2012-01-01 2012-01-01 false CDC Liquidation of loans and debt... BUSINESS LOANS Development Company Loan Program (504) Authority of Cdcs to Perform Liquidation and Debt Collection Litigation § 120.975 CDC Liquidation of loans and debt collection litigation. (a) PCLP CDCs. If a...

13 CFR 120.975 - CDC Liquidation of loans and debt collection litigation.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 13 Business Credit and Assistance 1 2013-01-01 2013-01-01 false CDC Liquidation of loans and debt... BUSINESS LOANS Development Company Loan Program (504) Authority of Cdcs to Perform Liquidation and Debt Collection Litigation § 120.975 CDC Liquidation of loans and debt collection litigation. (a) PCLP CDCs. If a...

13 CFR 120.975 - CDC Liquidation of loans and debt collection litigation.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 13 Business Credit and Assistance 1 2011-01-01 2011-01-01 false CDC Liquidation of loans and debt... BUSINESS LOANS Development Company Loan Program (504) Authority of Cdcs to Perform Liquidation and Debt Collection Litigation § 120.975 CDC Liquidation of loans and debt collection litigation. (a) PCLP CDCs. If a...

12 CFR 160.40 - Commercial paper and corporate debt securities.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 12 Banks and Banking 1 2012-01-01 2012-01-01 false Commercial paper and corporate debt securities... LENDING AND INVESTMENT § 160.40 Commercial paper and corporate debt securities. Pursuant to HOLA section 5... paragraph (a)(1)(i) of this section. (2) Corporate debt securities must be: (i) Securities that may be sold...

A Handbook on Debt Management for Colleges and Universities.

ERIC Educational Resources Information Center

Forrester, Robert T.

Between 1983 and 1986, colleges and universities issued about $20 billion of debt for facilities and student financing, and it is predicted that billions of dollars of new debt will be needed for building renovation. Debt capacity, management, and accounting are now major issues, and the purpose of this book is to provide a handy reference manual…

34 CFR 30.35 - What procedures does the Secretary follow to report debts to consumer reporting agencies?

Code of Federal Regulations, 2010 CFR

2010-07-01

... Debts to Consumer Reporting Agencies § 30.35 What procedures does the Secretary follow to report debts to consumer reporting agencies? (a)(1) The Secretary reports information regarding debts arising... 34 Education 1 2010-07-01 2010-07-01 false What procedures does the Secretary follow to report...

20 CFR 422.425 - How will we conduct our review of the debt?

Code of Federal Regulations, 2010 CFR

2010-04-01

... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false How will we conduct our review of the debt? 422.425 Section 422.425 Employees' Benefits SOCIAL SECURITY ADMINISTRATION ORGANIZATION AND PROCEDURES Collection of Debts by Administrative Wage Garnishment § 422.425 How will we conduct our review of the debt...

A Lifetime of Student Debt? Not Likely

ERIC Educational Resources Information Center

Wilson, Robin

2009-01-01

In this article, the author examines the issue of student debt. Despite tales of gargantuan student debt burdens for some college graduates, studies show that most students borrow sensibly, pay it back, and are better off for having gone to college. But for a vocal minority of borrowers, problems with student-loan debt are very real. About 8…

Student Debt and the Class of 2011

ERIC Educational Resources Information Center

Reed, Matthew; Cochrane, Debbie

2012-01-01

Student Debt and the Class of 2011 is the seventh annual report on the cumulative student loan debt of recent graduates from four-year public and private nonprofit colleges. The authors' analysis found that the debt levels of students who graduate with loans continued to rise, with considerable variation among states as well as among colleges. The…

15 CFR 19.14 - How will Commerce entities report Commerce debts to credit bureaus?

Code of Federal Regulations, 2012 CFR

2012-01-01

... 15 Commerce and Foreign Trade 1 2012-01-01 2012-01-01 false How will Commerce entities report Commerce debts to credit bureaus? 19.14 Section 19.14 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.14 How will Commerce entities...

15 CFR 19.14 - How will Commerce entities report Commerce debts to credit bureaus?

Code of Federal Regulations, 2013 CFR

2013-01-01

... 15 Commerce and Foreign Trade 1 2013-01-01 2013-01-01 false How will Commerce entities report Commerce debts to credit bureaus? 19.14 Section 19.14 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.14 How will Commerce entities...

15 CFR 19.14 - How will Commerce entities report Commerce debts to credit bureaus?

Code of Federal Regulations, 2011 CFR

2011-01-01

... 15 Commerce and Foreign Trade 1 2011-01-01 2011-01-01 false How will Commerce entities report Commerce debts to credit bureaus? 19.14 Section 19.14 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.14 How will Commerce entities...

15 CFR 19.14 - How will Commerce entities report Commerce debts to credit bureaus?

Code of Federal Regulations, 2014 CFR

2014-01-01

... 15 Commerce and Foreign Trade 1 2014-01-01 2014-01-01 false How will Commerce entities report Commerce debts to credit bureaus? 19.14 Section 19.14 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.14 How will Commerce entities...

15 CFR 19.14 - How will Commerce entities report Commerce debts to credit bureaus?

Code of Federal Regulations, 2010 CFR

2010-01-01

... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false How will Commerce entities report Commerce debts to credit bureaus? 19.14 Section 19.14 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.14 How will Commerce entities...

36 CFR 1011.15 - How will the Presidio Trust refer debts to private collection contractors?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false How will the Presidio Trust... Property PRESIDIO TRUST DEBT COLLECTION Procedures To Collect Presidio Trust Debts § 1011.15 How will the Presidio Trust refer debts to private collection contractors? The Presidio Trust will transfer delinquent...

Three types of rescue can avert extinction in a changing environment

USDA-ARS?s Scientific Manuscript database

Setting aside high quality, large areas of habitat to protect threatened populations is becoming increasingly difficult as humans fragment and degrade the environment. Biologists and managers therefore must determine the best way to shepherd small populations through the dual challenges of reduction...

The relationship between IR, optical, and UV extinction

NASA Technical Reports Server (NTRS)

Cardelli, Jason A.; Clayton, Geoffrey C.; Mathis, John S.

1989-01-01

An analysis is presented for the variability of absolute IR, optical, and UV extinction, A(sub lambda), derived through the ratio of total-to-selective extinction, R, for 31 lines of sight for which reliable UV extinction parameters were derived. These data sample a wide range of environments and are characterized by 2.5 is less than or equal to R is less than or equal to 6.0. It was found that there is a strong linear dependence between extinction expressed as A(sub lambda)/A(sub V) and 1/R for 1.25 micron is less than or equal to lambda is less than or equal to 0.12 micron. Differences in the general shape of extinction curves are largely due to variations in shape of optical/near-UV extinction corresponding to changes in R, with A(sub lambda)/A(sub V) decreasing for increasing R. From a least-squares fit of the observed R-dependence as a function of wavelength for 0.8/micron is less than or greater than 1/lambda is less than or equal to 8.3/micron, an analytic expression was generated from which IR, optical, and UV extinction curves of the form A(sub lambda)/A(sub V) can be reproduced with reasonable accuracy from a knowledge of R. It was also found that the absolute bump strength normalized to A(sub V) shows a general decrease with increasing R, suggesting that some fraction of bump grains may be selectively incorporated into coagulated grains. Finally, it was found that absolute extinction normalized by suitably chosen color indices results in a minimization of the R-dependence of portions of the UV curve, allowing A(sub lambda) to be estimated for these wavelengths independent of R.

7 CFR 3430.61 - Debt collection.

Code of Federal Regulations, 2010 CFR

2010-01-01

...-GENERAL AWARD ADMINISTRATIVE PROVISIONS Post-Award and Closeout § 3430.61 Debt collection. The collection... funds, unobligated balances, or other circumstances, are subject to the Department's debt collection...

Can medical students afford to choose primary care? An economic analysis of physician education debt repayment.

PubMed

Youngclaus, James A; Koehler, Paul A; Kotlikoff, Laurence J; Wiecha, John M

2013-01-01

Some discussions of physician specialty choice imply that indebted medical students avoid choosing primary care because education debt repayment seems economically unfeasible. The authors analyzed whether a physician earning a typical primary care salary can repay the current median level of education debt and meet standard household expenses without incurring additional debt. In 2010-2011, the authors used comprehensive financial planning software to model the annual finances for a fictional physician's household to compare the impact of various debt levels, repayment plans, and living expenses across three specialties. To accurately develop this spending model, they used published data from federal and local agencies, real estate sources, and national organizations. Despite growing debt levels, the authors found that physicians in all specialties can repay the current level of education debt without incurring more debt. However, some scenarios, typically those with higher borrowing levels, required trade-offs and compromises. For example, extended repayment plans require large increases in the total amount of interest repaid and the number of repayment years required, and the use of a federal loan forgiveness/repayment program requires a service obligation such as working at a nonprofit or practicing in a medically underserved area. A primary care career remains financially viable for medical school graduates with median levels of education debt. Graduates pursuing primary care with higher debt levels need to consider additional strategies to support repayment such as extended repayment terms, use of a federal loan forgiveness/repayment program, or not living in the highest-cost areas.

Debt Profiles of Model Students: The Projected Debt of Highly Productive Students and Its Economic Impact

ERIC Educational Resources Information Center

Fincher, Mark E.

2017-01-01

A common misperception suggests that a high-achieving student can easily complete a degree with very limited debt, and that students with high levels of debt are thus underachievers. This assumption is supported by memories of previous decades when it was realistically possible for most students to work their way through college. This view,…

15 CFR 19.16 - When will Commerce entities refer Commerce debts to the Department of Justice?

Code of Federal Regulations, 2014 CFR

2014-01-01

... 15 Commerce and Foreign Trade 1 2014-01-01 2014-01-01 false When will Commerce entities refer Commerce debts to the Department of Justice? 19.16 Section 19.16 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.16 When will...

15 CFR 19.11 - How will Commerce entities use tax refund offset to collect a Commerce debt?

Code of Federal Regulations, 2014 CFR

2014-01-01

... 15 Commerce and Foreign Trade 1 2014-01-01 2014-01-01 false How will Commerce entities use tax refund offset to collect a Commerce debt? 19.11 Section 19.11 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.11 How will...

15 CFR 19.11 - How will Commerce entities use tax refund offset to collect a Commerce debt?

Code of Federal Regulations, 2013 CFR

2013-01-01

... 15 Commerce and Foreign Trade 1 2013-01-01 2013-01-01 false How will Commerce entities use tax refund offset to collect a Commerce debt? 19.11 Section 19.11 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.11 How will...

15 CFR 19.11 - How will Commerce entities use tax refund offset to collect a Commerce debt?

Code of Federal Regulations, 2011 CFR

2011-01-01

... 15 Commerce and Foreign Trade 1 2011-01-01 2011-01-01 false How will Commerce entities use tax refund offset to collect a Commerce debt? 19.11 Section 19.11 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.11 How will...

15 CFR 19.16 - When will Commerce entities refer Commerce debts to the Department of Justice?

Code of Federal Regulations, 2012 CFR

2012-01-01

... 15 Commerce and Foreign Trade 1 2012-01-01 2012-01-01 false When will Commerce entities refer Commerce debts to the Department of Justice? 19.16 Section 19.16 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.16 When will...

15 CFR 19.11 - How will Commerce entities use tax refund offset to collect a Commerce debt?

Code of Federal Regulations, 2010 CFR

2010-01-01

... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false How will Commerce entities use tax refund offset to collect a Commerce debt? 19.11 Section 19.11 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.11 How will...

15 CFR 19.11 - How will Commerce entities use tax refund offset to collect a Commerce debt?

Code of Federal Regulations, 2012 CFR

2012-01-01

... 15 Commerce and Foreign Trade 1 2012-01-01 2012-01-01 false How will Commerce entities use tax refund offset to collect a Commerce debt? 19.11 Section 19.11 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.11 How will...

15 CFR 19.16 - When will Commerce entities refer Commerce debts to the Department of Justice?

Code of Federal Regulations, 2013 CFR

2013-01-01

... 15 Commerce and Foreign Trade 1 2013-01-01 2013-01-01 false When will Commerce entities refer Commerce debts to the Department of Justice? 19.16 Section 19.16 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.16 When will...

15 CFR 19.16 - When will Commerce entities refer Commerce debts to the Department of Justice?

Code of Federal Regulations, 2011 CFR

2011-01-01

... 15 Commerce and Foreign Trade 1 2011-01-01 2011-01-01 false When will Commerce entities refer Commerce debts to the Department of Justice? 19.16 Section 19.16 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.16 When will...

15 CFR 19.16 - When will Commerce entities refer Commerce debts to the Department of Justice?

Code of Federal Regulations, 2010 CFR

2010-01-01

... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false When will Commerce entities refer Commerce debts to the Department of Justice? 19.16 Section 19.16 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.16 When will...

25 CFR 513.20 - What debts can the Commission refer to Treasury for collection by administrative and tax refund...

Code of Federal Regulations, 2010 CFR

2010-04-01

... COMMISSION, DEPARTMENT OF THE INTERIOR GENERAL PROVISIONS DEBT COLLECTION Administrative and Tax Refund Offset § 513.20 What debts can the Commission refer to Treasury for collection by administrative and tax... person to the Treasury for administrative and tax refund offset if the debt: (1) Has been delinquent for...

25 CFR 513.21 - What notice will a debtor be given of the Commission's intent to collect a debt through...

Code of Federal Regulations, 2010 CFR

2010-04-01

... intent to collect a debt through administrative and tax refund offset? 513.21 Section 513.21 Indians... collect a debt through administrative and tax refund offset? (a) The Commission will give the debtor... after the date of the notice, the Commission will refer the debt to Treasury for administrative and tax...

Student Loan Debt for Community College Transfer Students and How Debt Information Letters Impact Future Borrowing Decisions

ERIC Educational Resources Information Center

Mckinney, Kenneth Paul

2017-01-01

There has been a proliferation of student loan debt over the past decade. The indebtedness that students incur while attending college reduces their discretionary income once they enter repayment after graduation. For graduates, there is an opportunity cost along with personal and professional life decisions being made based on this debt. For…

15 CFR 19.4 - What notice will Commerce entities send to a debtor when collecting a Commerce debt?

Code of Federal Regulations, 2010 CFR

2010-01-01

... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false What notice will Commerce entities send to a debtor when collecting a Commerce debt? 19.4 Section 19.4 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.4...

24 CFR 17.159 - Application of offset funds: Federal payment is insufficient to cover amount of debt.

Code of Federal Regulations, 2010 CFR

2010-04-01

...: Federal payment is insufficient to cover amount of debt. 17.159 Section 17.159 Housing and Urban... Procedures for the Collection of Claims by the Government Irs Tax Refund and Federal Payment Offset... insufficient to cover amount of debt. If an offset of a Federal payment is insufficient to satisfy a debt, the...

Financial Factors and Institutional Characteristics That Relate to the Long-Term Debt of U.S. Four-Year Public Colleges and Universities

ERIC Educational Resources Information Center

Keith, Dana Sims

2013-01-01

Debt for public colleges and universities has been increasing while financial resources, which provide the support to repay debt, have been declining. As debt increases in proportion to assets, the risk profile of a college or university increases. This study examined the relationships between financial variables and institutional characteristics…

17 CFR 240.15c3-1g - Conditions for ultimate holding companies of certain brokers or dealers (Appendix G to 17 CFR 240...

Code of Federal Regulations, 2014 CFR

2014-04-01

... conditions of paragraphs (a)(1)(ii)(A) through (D) of this appendix G; (B) Subordinated debt if the original weighted average maturity of the subordinated debt is at least five years; each subordinated debt... the Securities Investor Protection Corporation; the subordinated debt is unsecured and subordinated in...

36 CFR 1011.21 - How do other Federal agencies use the offset process to collect debts from payments issued by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... use the offset process to collect debts from payments issued by the Presidio Trust? 1011.21 Section 1011.21 Parks, Forests, and Public Property PRESIDIO TRUST DEBT COLLECTION Procedures for Offset of Presidio Trust Payments To Collect Debts Owed To Other Federal Agencies § 1011.21 How do other Federal...

"I Fully Expect to Die with This Debt"

ERIC Educational Resources Information Center

Patton, Stacey

2013-01-01

Student-loan debt is not just a problem for young, recent college graduates searching for their first jobs. Growing numbers of adults nearing the ends of their careers are accumulating such big debt, too, and they don't have a lifetime to pay it back. In fact, student-loan debt is growing fastest among adults ages 60 and older, with more than two…

26 CFR 1.1272-2 - Treatment of debt instruments purchased at a premium.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 11 2010-04-01 2010-04-01 true Treatment of debt instruments purchased at a....1272-2 Treatment of debt instruments purchased at a premium. (a) In general. Under section 1272(c)(1), if a holder purchases a debt instrument at a premium, the holder does not include any OID in gross...

7 CFR 3.79 - Review of USDA records related to the debt.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 1 2013-01-01 2013-01-01 false Review of USDA records related to the debt. 3.79....79 Review of USDA records related to the debt. (a) Notification by employee. An employee who intends to inspect or copy USDA records related to the debt must send a letter to USDA stating his or her...

7 CFR 3.79 - Review of USDA records related to the debt.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 1 2010-01-01 2010-01-01 false Review of USDA records related to the debt. 3.79....79 Review of USDA records related to the debt. (a) Notification by employee. An employee who intends to inspect or copy USDA records related to the debt must send a letter to USDA stating his or her...

7 CFR 3.79 - Review of USDA records related to the debt.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 1 2011-01-01 2011-01-01 false Review of USDA records related to the debt. 3.79....79 Review of USDA records related to the debt. (a) Notification by employee. An employee who intends to inspect or copy USDA records related to the debt must send a letter to USDA stating his or her...

7 CFR 3.79 - Review of USDA records related to the debt.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 1 2012-01-01 2012-01-01 false Review of USDA records related to the debt. 3.79....79 Review of USDA records related to the debt. (a) Notification by employee. An employee who intends to inspect or copy USDA records related to the debt must send a letter to USDA stating his or her...

7 CFR 3.79 - Review of USDA records related to the debt.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 1 2014-01-01 2014-01-01 false Review of USDA records related to the debt. 3.79....79 Review of USDA records related to the debt. (a) Notification by employee. An employee who intends to inspect or copy USDA records related to the debt must send a letter to USDA stating his or her...

15 CFR 19.12 - How will Commerce entities offset a Federal employee's salary to collect a Commerce debt?

Code of Federal Regulations, 2011 CFR

2011-01-01

... 15 Commerce and Foreign Trade 1 2011-01-01 2011-01-01 false How will Commerce entities offset a Federal employee's salary to collect a Commerce debt? 19.12 Section 19.12 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.12...

15 CFR 19.12 - How will Commerce entities offset a Federal employee's salary to collect a Commerce debt?

Code of Federal Regulations, 2012 CFR

2012-01-01

... 15 Commerce and Foreign Trade 1 2012-01-01 2012-01-01 false How will Commerce entities offset a Federal employee's salary to collect a Commerce debt? 19.12 Section 19.12 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.12...

15 CFR 19.12 - How will Commerce entities offset a Federal employee's salary to collect a Commerce debt?

Code of Federal Regulations, 2014 CFR

2014-01-01

... 15 Commerce and Foreign Trade 1 2014-01-01 2014-01-01 false How will Commerce entities offset a Federal employee's salary to collect a Commerce debt? 19.12 Section 19.12 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.12...

15 CFR 19.12 - How will Commerce entities offset a Federal employee's salary to collect a Commerce debt?

Code of Federal Regulations, 2013 CFR

2013-01-01

... 15 Commerce and Foreign Trade 1 2013-01-01 2013-01-01 false How will Commerce entities offset a Federal employee's salary to collect a Commerce debt? 19.12 Section 19.12 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.12...

36 CFR 1011.7 - When will the Presidio Trust compromise a debt?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false When will the Presidio Trust... Procedures To Collect Presidio Trust Debts § 1011.7 When will the Presidio Trust compromise a debt? (a... debt owed to the Presidio Trust that is not recovered as the result of a compromise will be reported to...

36 CFR 1011.16 - When will the Presidio Trust refer debts to the Department of Justice?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false When will the Presidio Trust... PRESIDIO TRUST DEBT COLLECTION Procedures To Collect Presidio Trust Debts § 1011.16 When will the Presidio... collection activity. The Presidio Trust will refer debts having a principal balance over $100,000, or such...

78 FR 4425 - Notice of Proposed Information Collection: Comment Request; Debt Resolution Program

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-22

... collect debt owed to the agency. As part of the collection process, demand for repayment is made on the... offers to repay the debt result in information collections. Borrowers who wish to pay less than the full... process, demand for repayment is made on the debtor(s). In response, debtors opt to ignore the debt, pay...

Debt on graduation, expected place of practice, and career aspirations of Auckland Medical School students.

PubMed

O'Grady, G; Fitzjohn, J

2001-10-26

To determine the debt level that current Auckland medical students expect to graduate with, and evaluate this debt in the context of their career aspirations and intended place of practice. Simple check-box and fill-in-the-blank surveys were distributed to Auckland University medical students in Years 1 through to 5 during their second week of scheduled lectures in March 2000. Students were asked to provide demographic details, then complete sections on debt and career aspirations. 70% of Auckland medical students participated. Average expected debt was between $60000 to $70000. Predicted size of graduation debt was significantly related with plans to practice medicine overseas, and this trend was especially strong among females. In addition, Maori and Polynesian students bear a disproportionate level of the student debt burden compared to Pakeha and Asian groups. 77% of students indicated a preference for working in private or hospital specialty work. Student debt will have major effects on the composition of the New Zealand medical workforce over coming years. More attention must be paid to the national picture of medical student indebtedness if adequate workforce planning is to be possible.

Extinction of a fast-growing oyster and changing ocean circulation in Pliocene tropical America

NASA Astrophysics Data System (ADS)

Kirby, Michael X.; Jackson, Jeremy B. C.

2004-12-01

Ocean circulation changed profoundly in the late Cenozoic around tropical America as a result of constriction and final closure of the Central American seaway. In response, regional planktonic productivity is thought to have decreased in the Caribbean Sea. Previous studies have shown that shallow-marine communities reflect these changes by reorganizing from a suspension-feeder dominated community to a more carbonate-rich, phototrophic-based community. Although changes in diversity, abundance, and body size of various shallow-marine invertebrates have previously been examined, no study has specifically used growth rate in suspension feeders to examine the effect that changes in ocean circulation may have had on shallow-marine communities. Here we show that a fast-growing oyster went extinct concurrently with changes in ocean circulation and planktonic productivity in the Pliocene. Faster-growing Crassostrea cahobasensis went extinct, whereas slower-growing Crassostrea virginica and columbiensis survived to the Holocene. Miocene Pliocene C. cahobasensis grew 522% faster in shell carbonate and 251% faster in biomass relative to Quaternary C. virginica and C. columbiensis. Although differences in growth are due to proximate differences in environment, the disappearance of faster-growing C. cahobasensis from shallow-marine environments and the continued survival of slower-growing C. virginica and C. columbiensis in marginal-marine environments (e.g., estuaries, lagoons) is consistent with the view that concurrent changes in ocean circulation and declining primary production resulted in the restriction of Crassostrea to marginal-marine environments.

School Librarian...R.I.P.

ERIC Educational Resources Information Center

Gay, E. Nola

1994-01-01

Provides a satirical view of the extinction of school librarians. Highlights include educational technology development; changing professional environments; mainstreaming; certification; and the industrialization of education. (AEF)

Molecular gas in supernova local environments unveiled by EDGE

NASA Astrophysics Data System (ADS)

Galbany, L.; Mora, L.; González-Gaitán, S.; Bolatto, A.; Dannerbauer, H.; López-Sánchez, Á. R.; Maeda, K.; Pérez, S.; Pérez-Torres, M. A.; Sánchez, S. F.; Wong, T.; Badenes, C.; Blitz, L.; Marino, R. A.; Utomo, D.; Van de Ven, G.

2017-06-01

CO observations allow estimation of the gas content of molecular clouds, which trace the reservoir of cold gas fuelling star formation, as well as determination of extinction via H2 column density, N(H2). Here, we study millimetric and optical properties at 26 supernovae (SNe) locations of different types in a sample of 23 nearby galaxies, by combining molecular 12C16O (J = 1 → 0) resolved maps from the Extragalactic Database for Galaxy Evolution (EDGE) survey and optical Integral Field Spectroscopy (IFS) from the Calar Alto Legacy Integral Field Area (CALIFA) survey. We found an even clearer separation between type II and type Ibc SNe in terms of molecular gas than is found in the optical using Hα emission as a proxy for the current star formation (SF) rate, which reinforces the fact that SNe Ibc are more associated with SF environments. While AV at SN locations is similar for SNe II and SNe Ibc and higher than for SNe Ia, N(H2) is significantly higher for SNe Ibc than for SNe II and Ia. When compared with alternative extinction estimations made directly from SN photometry and spectroscopy, we find that our SNe Ibc also have redder colour excess, but showed standard Na I D absorption pseudo-equivalent widths (˜1 Å). In some cases, we find no extinction when IT is estimated from the environment but high amounts of extinction when measured from SN observations, which suggests that circumstellar material or dust sublimation may be playing a role. This work serves as a benchmark for future studies combining last-generation millimetre and optical IFS instruments to reveal the local environmental properties of extragalactic SNe.

Tropical ancient DNA reveals relationships of the extinct Bahamian giant tortoise Chelonoidis alburyorum

PubMed Central

Kehlmaier, Christian; Barlow, Axel; Hastings, Alexander K.; Vamberger, Melita; Paijmans, Johanna L. A.; Steadman, David W.; Albury, Nancy A.; Franz, Richard; Hofreiter, Michael

2017-01-01

Ancient DNA of extinct species from the Pleistocene and Holocene has provided valuable evolutionary insights. However, these are largely restricted to mammals and high latitudes because DNA preservation in warm climates is typically poor. In the tropics and subtropics, non-avian reptiles constitute a significant part of the fauna and little is known about the genetics of the many extinct reptiles from tropical islands. We have reconstructed the near-complete mitochondrial genome of an extinct giant tortoise from the Bahamas (Chelonoidis alburyorum) using an approximately 1 000-year-old humerus from a water-filled sinkhole (blue hole) on Great Abaco Island. Phylogenetic and molecular clock analyses place this extinct species as closely related to Galápagos (C. niger complex) and Chaco tortoises (C. chilensis), and provide evidence for repeated overseas dispersal in this tortoise group. The ancestors of extant Chelonoidis species arrived in South America from Africa only after the opening of the Atlantic Ocean and dispersed from there to the Caribbean and the Galápagos Islands. Our results also suggest that the anoxic, thermally buffered environment of blue holes may enhance DNA preservation, and thus are opening a window for better understanding evolution and population history of extinct tropical species, which would likely still exist without human impact. PMID:28077774

Neural signals of vicarious extinction learning

PubMed Central

Haaker, Jan; Selbing, Ida; Olsson, Andreas

2016-01-01

Social transmission of both threat and safety is ubiquitous, but little is known about the neural circuitry underlying vicarious safety learning. This is surprising given that these processes are critical to flexibly adapt to a changeable environment. To address how the expression of previously learned fears can be modified by the transmission of social information, two conditioned stimuli (CS + s) were paired with shock and the third was not. During extinction, we held constant the amount of direct, non-reinforced, exposure to the CSs (i.e. direct extinction), and critically varied whether another individual—acting as a demonstrator—experienced safety (CS + vic safety) or aversive reinforcement (CS + vic reinf). During extinction, ventromedial prefrontal cortex (vmPFC) responses to the CS + vic reinf increased but decreased to the CS + vic safety. This pattern of vmPFC activity was reversed during a subsequent fear reinstatement test, suggesting a temporal shift in the involvement of the vmPFC. Moreover, only the CS + vic reinf association recovered. Our data suggest that vicarious extinction prevents the return of conditioned fear responses, and that this efficacy is reflected by diminished vmPFC involvement during extinction learning. The present findings may have important implications for understanding how social information influences the persistence of fear memories in individuals suffering from emotional disorders. PMID:27278792

Tropical ancient DNA reveals relationships of the extinct Bahamian giant tortoise Chelonoidis alburyorum.

PubMed

Kehlmaier, Christian; Barlow, Axel; Hastings, Alexander K; Vamberger, Melita; Paijmans, Johanna L A; Steadman, David W; Albury, Nancy A; Franz, Richard; Hofreiter, Michael; Fritz, Uwe

2017-01-11

Ancient DNA of extinct species from the Pleistocene and Holocene has provided valuable evolutionary insights. However, these are largely restricted to mammals and high latitudes because DNA preservation in warm climates is typically poor. In the tropics and subtropics, non-avian reptiles constitute a significant part of the fauna and little is known about the genetics of the many extinct reptiles from tropical islands. We have reconstructed the near-complete mitochondrial genome of an extinct giant tortoise from the Bahamas (Chelonoidis alburyorum) using an approximately 1 000-year-old humerus from a water-filled sinkhole (blue hole) on Great Abaco Island. Phylogenetic and molecular clock analyses place this extinct species as closely related to Galápagos (C. niger complex) and Chaco tortoises (C. chilensis), and provide evidence for repeated overseas dispersal in this tortoise group. The ancestors of extant Chelonoidis species arrived in South America from Africa only after the opening of the Atlantic Ocean and dispersed from there to the Caribbean and the Galápagos Islands. Our results also suggest that the anoxic, thermally buffered environment of blue holes may enhance DNA preservation, and thus are opening a window for better understanding evolution and population history of extinct tropical species, which would likely still exist without human impact. © 2017 The Author(s).

Seeing red: Americans driven into debt by medical bills. Results from a National Survey.

PubMed

Doty, Michelle M; Edwards, Jennifer N; Holmgren, Alyssa L

2005-08-01

New analysis of the 2003 Commonwealth Fund Biennial Health Insurance Survey reveals that an estimated 77 million Americans age 19 and older--nearly two of five (37%) adults--have difficulty paying medical bills, have accrued medical debt, or both. Working-age adults incur significantly higher rates of medical bill and debt problems than adults 65 and older, with rates highest among the uninsured. Even working-age adults who are continually insured have problems paying their medical bills and have medical debt. Unpaid medical bills and medical debt can limit access to health care: two-thirds of people with a medical bill or debt problem went without needed care because of cost--nearly three times the rate of those without these financial problems.

Early Triassic wrinkle structures on land: stressed environments and oases for life

NASA Astrophysics Data System (ADS)

Chu, Daoliang; Tong, Jinnan; Song, Haijun; Benton, Michael J.; Bottjer, David J.; Song, Huyue; Tian, Li

2015-06-01

Wrinkle structures in rocks younger than the Permian-Triassic (P-Tr) extinction have been reported repeatedly in marine strata, but rarely mentioned in rocks recording land. Here, three newly studied terrestrial P-Tr boundary rock succession in North China have yielded diverse wrinkle structures. All of these wrinkles are preserved in barely bioturbated shore-shallow lacustrine siliciclastic deposits of the Liujiagou Formation. Conversely, both the lacustrine siliciclastic deposits of the underlying Sunjiagou Formation and the overlying Heshanggou Formation show rich bioturbation, but no wrinkle structures or other microbial-related structures. The occurrence of terrestrial wrinkle structures in the studied sections reflects abnormal hydrochemical and physical environments, presumably associated with the extinction of terrestrial organisms. Only very rare trace fossils occurred in the aftermath of the P-Tr extinction, but most of them were preserved together with the microbial mats. This suggests that microbial mats acted as potential oases for the surviving aquatic animals, as a source of food and oxygen. The new finds suggests that extreme environmental stresses were prevalent both in the sea and on land through most of the Early Triassic.

Influence of environmental factors on college alcohol drinking patterns.

PubMed

Bani, Ridouan; Hameed, Rasheed; Szymanowski, Steve; Greenwood, Priscilla; Kribs-Zaleta, Christopher M; Mubayi, Anuj

2013-01-01

Alcohol abuse is a major problem, especially among students on and around college campuses. We use the mathematical framework of [16] and study the role of environmental factors on the long term dynamics of an alcohol drinking population. Sensitivity and uncertainty analyses are carried out on the relevant functions (for example, on the drinking reproduction number and the extinction time of moderate and heavy drinking because of interventions) to understand the impact of environmental interventions on the distributions of drinkers. The reproduction number helps determine whether or not the high-risk alcohol drinking behavior will spread and become persistent in the population, whereas extinction time of high-risk drinking measures the effectiveness of control programs. We found that the reproduction number is most sensitive to social interactions, while the time to extinction of high-risk drinkers is significantly sensitive to the intervention programs that reduce initiation, and the college drop-out rate. The results also suggest that in a population, higher rates of intervention programs in low-risk environments (more than intervention rates in high-risk environments) are needed to reduce heavy drinking in the population.

Hunger Promotes Fear Extinction by Activation of an Amygdala Microcircuit

PubMed Central

Verma, Dilip; Wood, James; Lach, Gilliard; Herzog, Herbert; Sperk, Guenther; Tasan, Ramon

2016-01-01

Emotions control evolutionarily-conserved behavior that is central to survival in a natural environment. Imbalance within emotional circuitries, however, may result in malfunction and manifestation of anxiety disorders. Thus, a better understanding of emotional processes and, in particular, the interaction of the networks involved is of considerable clinical relevance. Although neurobiological substrates of emotionally controlled circuitries are increasingly evident, their mutual influences are not. To investigate interactions between hunger and fear, we performed Pavlovian fear conditioning in fasted wild-type mice and in mice with genetic modification of a feeding-related gene. Furthermore, we analyzed in these mice the electrophysiological microcircuits underlying fear extinction. Short-term fasting before fear acquisition specifically impaired long-term fear memory, whereas fasting before fear extinction facilitated extinction learning. Furthermore, genetic deletion of the Y4 receptor reduced appetite and completely impaired fear extinction, a phenomenon that was rescued by fasting. A marked increase in feed-forward inhibition between the basolateral and central amygdala has been proposed as a synaptic correlate of fear extinction and involves activation of the medial intercalated cells. This form of plasticity was lost in Y4KO mice. Fasting before extinction learning, however, resulted in specific activation of the medial intercalated neurons and re-established the enhancement of feed-forward inhibition in this amygdala microcircuit of Y4KO mice. Hence, consolidation of fear and extinction memories is differentially regulated by hunger, suggesting that fasting and modification of feeding-related genes could augment the effectiveness of exposure therapy and provide novel drug targets for treatment of anxiety disorders. PMID:26062787

Computational search for hypotheses concerning the endocannabinoid contribution to the extinction of fear conditioning.

PubMed

Anastasio, Thomas J

2013-01-01

Fear conditioning, in which a cue is conditioned to elicit a fear response, and extinction, in which a previously conditioned cue no longer elicits a fear response, depend on neural plasticity occurring within the amygdala. Projection neurons in the basolateral amygdala (BLA) learn to respond to the cue during fear conditioning, and they mediate fear responding by transferring cue signals to the output stage of the amygdala. Some BLA projection neurons retain their cue responses after extinction. Recent work shows that activation of the endocannabinoid system is necessary for extinction, and it leads to long-term depression (LTD) of the GABAergic synapses that inhibitory interneurons make onto BLA projection neurons. Such GABAergic LTD would enhance the responses of the BLA projection neurons that mediate fear responding, so it would seem to oppose, rather than promote, extinction. To address this paradox, a computational analysis of two well-known conceptual models of amygdaloid plasticity was undertaken. The analysis employed exhaustive state-space search conducted within a declarative programming environment. The analysis reveals that GABAergic LTD actually increases the number of synaptic strength configurations that achieve extinction while preserving the cue responses of some BLA projection neurons in both models. The results suggest that GABAergic LTD helps the amygdala retain cue memory during extinction even as the amygdala learns to suppress the previously conditioned response. The analysis also reveals which features of both models are essential for their ability to achieve extinction with some cue memory preservation, and suggests experimental tests of those features.

Computational search for hypotheses concerning the endocannabinoid contribution to the extinction of fear conditioning

PubMed Central

Anastasio, Thomas J.

2013-01-01

Fear conditioning, in which a cue is conditioned to elicit a fear response, and extinction, in which a previously conditioned cue no longer elicits a fear response, depend on neural plasticity occurring within the amygdala. Projection neurons in the basolateral amygdala (BLA) learn to respond to the cue during fear conditioning, and they mediate fear responding by transferring cue signals to the output stage of the amygdala. Some BLA projection neurons retain their cue responses after extinction. Recent work shows that activation of the endocannabinoid system is necessary for extinction, and it leads to long-term depression (LTD) of the GABAergic synapses that inhibitory interneurons make onto BLA projection neurons. Such GABAergic LTD would enhance the responses of the BLA projection neurons that mediate fear responding, so it would seem to oppose, rather than promote, extinction. To address this paradox, a computational analysis of two well-known conceptual models of amygdaloid plasticity was undertaken. The analysis employed exhaustive state-space search conducted within a declarative programming environment. The analysis reveals that GABAergic LTD actually increases the number of synaptic strength configurations that achieve extinction while preserving the cue responses of some BLA projection neurons in both models. The results suggest that GABAergic LTD helps the amygdala retain cue memory during extinction even as the amygdala learns to suppress the previously conditioned response. The analysis also reveals which features of both models are essential for their ability to achieve extinction with some cue memory preservation, and suggests experimental tests of those features. PMID:23761759

Environmental change preceded Caribbean extinction by 2 million years

PubMed Central

O'Dea, Aaron; Jackson, Jeremy B. C.; Fortunato, Helena; Smith, J. Travis; D'Croz, Luis; Johnson, Kenneth G.; Todd, Jonathan A.

2007-01-01

Paleontologists typically treat major episodes of extinction as single and distinct events in which a major environmental perturbation results in a synchronous evolutionary response. Alternatively, the causes of biotic change may be multifaceted and extinction may lag behind the changes ultimately responsible because of nonlinear ecological dynamics. We examined these alternatives for the major episode of Caribbean extinction 2 million years ago (Ma). Isolation of the Caribbean from the Eastern Pacific by uplift of the Panamanian Isthmus was associated with synchronous changes in Caribbean near shore environments and community composition between 4.25 and 3.45 Ma. Seasonal fluctuations in Caribbean seawater temperature decreased 3-fold, carbonate deposition increased, and there was a striking, albeit patchy, shift in dominance of benthic ecosystems from heterotrophic mollusks to mixotrophic reef corals and calcareous algae. All of these changes correspond well with a simple model of decreased upwelling and collapse in planktonic productivity associated with the final stages of the closure of the isthmian barrier. However, extinction rates of mollusks and corals did not increase until 3–2 Ma and sharply peaked between 2 and 1 Ma, even though extinction overwhelmingly affected taxa commonly associated with high productivity. This time lag suggests that something other than environmental change per se was involved in extinction that does not occur as a single event. Understanding cause and effect will require more taxonomically refined analysis of the changing abundance and distribution patterns of different ecological guilds in the 2 million years leading up to the relatively sudden peak in extinction. PMID:17369359

Hunger Promotes Fear Extinction by Activation of an Amygdala Microcircuit.

PubMed

Verma, Dilip; Wood, James; Lach, Gilliard; Herzog, Herbert; Sperk, Guenther; Tasan, Ramon

2016-01-01

Emotions control evolutionarily-conserved behavior that is central to survival in a natural environment. Imbalance within emotional circuitries, however, may result in malfunction and manifestation of anxiety disorders. Thus, a better understanding of emotional processes and, in particular, the interaction of the networks involved is of considerable clinical relevance. Although neurobiological substrates of emotionally controlled circuitries are increasingly evident, their mutual influences are not. To investigate interactions between hunger and fear, we performed Pavlovian fear conditioning in fasted wild-type mice and in mice with genetic modification of a feeding-related gene. Furthermore, we analyzed in these mice the electrophysiological microcircuits underlying fear extinction. Short-term fasting before fear acquisition specifically impaired long-term fear memory, whereas fasting before fear extinction facilitated extinction learning. Furthermore, genetic deletion of the Y4 receptor reduced appetite and completely impaired fear extinction, a phenomenon that was rescued by fasting. A marked increase in feed-forward inhibition between the basolateral and central amygdala has been proposed as a synaptic correlate of fear extinction and involves activation of the medial intercalated cells. This form of plasticity was lost in Y4KO mice. Fasting before extinction learning, however, resulted in specific activation of the medial intercalated neurons and re-established the enhancement of feed-forward inhibition in this amygdala microcircuit of Y4KO mice. Hence, consolidation of fear and extinction memories is differentially regulated by hunger, suggesting that fasting and modification of feeding-related genes could augment the effectiveness of exposure therapy and provide novel drug targets for treatment of anxiety disorders.

Global Governance 2025: At a Critical Juncture

DTIC Science & Technology

2010-09-01

them. Formal institutions remain largely unreformed and Western states probably must shoulder a disproportionate share of “global governance” as...might be in a better position but may still be fiscally constrained if its budgetary shortfalls and long-term debt problems remain unresolved...that undermine both the environment and investment. Reliance on domestic reserves of fossil fuels or long- term access to foreign fields makes

31 CFR 900.1 - Prescription of standards.

Code of Federal Regulations, 2010 CFR

2010-07-01

... the Debt Management Services, Financial Management Service, Department of the Treasury, 401 14th... regulations by Treasury. Rules governing the use of certain debt collection tools created under the Debt...

The Geochemistry of Mass Extinction

NASA Astrophysics Data System (ADS)

Kump, L. R.

2003-12-01

The course of biological evolution is inextricably linked to that of the environment through an intricate network of feedbacks that span all scales of space and time. Disruptions to the environment have biological consequences, and vice versa. Fossils provide the prima facie evidence for biotic disruptions: catastrophic losses of global biodiversity at various times in the Phanerozoic. However, the forensic evidence for the causes and environmental consequences of these mass extinctions resides primarily in the geochemical composition of sedimentary rocks deposited during the extinction intervals. Thus, advancement in our understanding of mass extinctions requires detailed knowledge obtained from both paleontological and geochemical records.This chapter reviews the state of knowledge concerning the geochemistry of the "big five" extinctions of the Phanerozoic (e.g., Sepkoski, 1993): the Late Ordovician (Hirnantian; 440 Ma), the Late Devonian (an extended or multiple event with its apex at the Frasnian-Famennian (F-F) boundary; 367 Ma), the Permian-Triassic (P-Tr; 251 Ma), the Triassic-Jurassic (Tr-J; 200 Ma), and the Cretaceous-Tertiary (K-T; 65 Ma). The focus on the big five is a matter of convenience, as there is a continuum in extinction rates from "background" to "mass extinction." Although much of the literature on extinctions centers on the causes and extents of biodiversity loss, in recent years paleontologists have begun to focus on recoveries (see, e.g., Hart, 1996; Kirchner and Weil, 2000; Erwin, 2001 and references therein).To the extent that the duration of the recovery interval may reflect a slow relaxation of the environment from perturbation, analysis of the geochemical record of recovery is an integral part of this effort. In interpreting the geochemical and biological records of recovery, we need to maintain a clear distinction among the characteristics of the global biota: their biodiversity (affected by differences in origination and extinction rates) and ecosystem function (guild structure, complexity of interactions, productivity). Geochemical records reflect attributes of ecosystem function, not biodiversity; low-diversity recovery faunas and floras may support pre-event productivities. Thus, geochemical and biodiversity recovery intervals are interdependent but not equivalent, and may not be of equal duration.From the biological point of view, there is an inevitable lag between peak extinction rates and peak origination rates, and the durations and underlying causes of the lags are topics of debate. Both intrinsic (e.g., the fact that ecospace is created as biodiversity increases producing positive feedback) and external (environmental) constraints are possible. Kirchner and Weil (2000) performed a time-series analysis of extinction and origination-rate data, and concluded that the lag is ˜10 Myr and independent of the magnitude of the event. Erwin (2001) raised the possibility that the 10 Myr lag may be an artifact of the coarseness of the timescales utilized, and discussed possible environmental and ecological limits on rate of recovery from mass extinction.The comparison of the geochemical records of the five major mass extinctions of the Phanerozoic reveals few commonalities. Most, but not all, exhibit sharp drops in the carbon isotopic composition (δ13C) of the surface ocean, indicating substantial disruptions to the global carbon cycle. The P-Tr and F-F events are associated with indicators of widespread anoxia and enhanced pyrite burial (positive δ34S excursions), whereas the Late Ordovician extinction occurred during a brief interlude of oxic conditions from general anoxia. Some are associated with sea-level transgressions from previous lowstands (P-Tr, Tr-J, K-T), but the Late Ordovician and F-F occurred during sea-level falls. Long-term climates change across all events, but span major coolings (Late Ordovician, F-F) to prominent warmings (P-Tr, Tr-J, K-T).Evidence for extraterrestrial influence is strong for the K-T, suggestive for the Tr-J and Late Permian, and missing for the F-F and Late Ordovician. What these times have in common is that all were times of biotic and environmental change. Long-term trends toward extreme environmental conditions presaged the Late Ordovician, F-F, and P-Tr events, whereas the Tr-J and K-T seem to have been abrupt shocks to the Earth system, perhaps belying their extraterrestrial cause. However, even for the K-T extinction there is indication of environmental and biotic change before the known impact event and mass extinction (e.g., Keller et al., 1993; Barrera, 1994; Abramovich and Keller, 2002).

Genomics of Extinct and Endangered Species (2011 JGI User Meeting)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shuster, Stephen

The U.S. Department of Energy Joint Genome Institute (JGI) invited scientists interested in the application of genomics to bioenergy and environmental issues, as well as all current and prospective users and collaborators, to attend the annual DOE JGI Genomics of Energy & Environment Meeting held March 22-24, 2011 in Walnut Creek, Calif. The emphasis of this meeting was on the genomics of renewable energy strategies, carbon cycling, environmental gene discovery, and engineering of fuel-producing organisms. The meeting features presentations by leading scientists advancing these topics. Stephen Shuster of Penn State University gives a presentation on "Genomics of Extinct and Endangeredmore » Species" at the 6th annual Genomics of Energy & Environment Meeting on March 23, 2011.« less

Extinction transition in bacterial colonies under forced convection

NASA Astrophysics Data System (ADS)

Neicu, T.; Pradhan, A.; Larochelle, D. A.; Kudrolli, A.

2000-07-01

We report the spatiotemporal response of Bacillus subtilis growing on a nutrient-rich layer of agar to ultraviolet (UV) radiation. Below a crossover temperature, the bacteria are confined to regions that are shielded from UV radiation. A forced convection of the population is effected by rotating a UV radiation shield relative to the Petri dish. The extinction speed at which the bacterial colony lags behind the shield is found to be qualitatively similar to the front velocity of the colony growing in the absence of a hostile environment as predicted by the model of Dahmen, Nelson, and Shnerb. A quantitative comparison is not possible without considering the slow dynamics and time-dependent interaction of the population with the hostile environment.

34 CFR 30.70 - How does the Secretary exercise discretion to compromise a debt or to suspend or terminate...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 34 Education 1 2011-07-01 2011-07-01 false How does the Secretary exercise discretion to compromise a debt or to suspend or terminate collection of a debt? 30.70 Section 30.70 Education Office of... Debt or the Suspension or Termination of Collection Action? § 30.70 How does the Secretary exercise...

15 CFR 19.19 - Will Commerce entities issue a refund if money is erroneously collected on a Commerce debt?

Code of Federal Regulations, 2010 CFR

2010-01-01

... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Will Commerce entities issue a refund if money is erroneously collected on a Commerce debt? 19.19 Section 19.19 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.19...

15 CFR 19.19 - Will Commerce entities issue a refund if money is erroneously collected on a Commerce debt?

Code of Federal Regulations, 2014 CFR

2014-01-01

... 15 Commerce and Foreign Trade 1 2014-01-01 2014-01-01 false Will Commerce entities issue a refund if money is erroneously collected on a Commerce debt? 19.19 Section 19.19 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.19...

15 CFR 19.19 - Will Commerce entities issue a refund if money is erroneously collected on a Commerce debt?

Code of Federal Regulations, 2013 CFR

2013-01-01

... 15 Commerce and Foreign Trade 1 2013-01-01 2013-01-01 false Will Commerce entities issue a refund if money is erroneously collected on a Commerce debt? 19.19 Section 19.19 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.19...

15 CFR 19.19 - Will Commerce entities issue a refund if money is erroneously collected on a Commerce debt?

Code of Federal Regulations, 2011 CFR

2011-01-01

... 15 Commerce and Foreign Trade 1 2011-01-01 2011-01-01 false Will Commerce entities issue a refund if money is erroneously collected on a Commerce debt? 19.19 Section 19.19 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.19...

15 CFR 19.19 - Will Commerce entities issue a refund if money is erroneously collected on a Commerce debt?

Code of Federal Regulations, 2012 CFR

2012-01-01

... 15 Commerce and Foreign Trade 1 2012-01-01 2012-01-01 false Will Commerce entities issue a refund if money is erroneously collected on a Commerce debt? 19.19 Section 19.19 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.19...

34 CFR 30.70 - How does the Secretary exercise discretion to compromise a debt or to suspend or terminate...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 34 Education 1 2010-07-01 2010-07-01 false How does the Secretary exercise discretion to compromise a debt or to suspend or terminate collection of a debt? 30.70 Section 30.70 Education Office of... Debt or the Suspension or Termination of Collection Action? § 30.70 How does the Secretary exercise...

7 CFR 792.19 - Referral of delinquent debts to IRS for tax refund offset.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 7 2010-01-01 2010-01-01 false Referral of delinquent debts to IRS for tax refund... POLICIES AND PROCEDURES § 792.19 Referral of delinquent debts to IRS for tax refund offset. FSA may refer legally enforceable delinquent debts to IRS to be offset against tax refunds due to debtors under 26 U.S.C...

36 CFR 1201.40 - Which debts can NARA refer to the Treasury for collection by offsetting tax refunds?

Code of Federal Regulations, 2010 CFR

2010-07-01

... Refund Offset § 1201.40 Which debts can NARA refer to the Treasury for collection by offsetting tax... reduce a tax refund by the amount of a past-due, legally enforceable debt owed to a Federal agency. (b) For purposes of this section, a past-due, legally enforceable debt referrable to the Treasury for tax...

45 CFR 2506.40 - Which debts can the Corporation refer to Treasury for collection by offsetting tax refunds?

Code of Federal Regulations, 2010 CFR

2010-10-01

... to Public Welfare (Continued) CORPORATION FOR NATIONAL AND COMMUNITY SERVICE COLLECTION OF DEBTS Tax... Treasury to reduce a tax refund by the amount of a past-due, legally enforceable debt owed to a Federal... for tax refund offset is a debt that is owed to the Corporation and: (1) Is at least $25.00; (2...

7 CFR 1403.18 - Referral of delinquent debts to IRS or tax refund offset.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false Referral of delinquent debts to IRS or tax refund... POLICIES AND PROCEDURES § 1403.18 Referral of delinquent debts to IRS or tax refund offset. CCC may refer legally enforceable delinquent debts to IRS to be offset against tax refunds due to debtors under 26 U.S.C...

Debt to Degree: A New Way of Measuring College Success. Charts You Can Trust

ERIC Educational Resources Information Center

Carey, Kevin; Dillon, Erin

2011-01-01

The American higher education system is plagued by two chronic problems: dropouts and debt. Barely half of the students who start college get a degree within six years, and graduation rates at less-selective colleges often hover at 25 percent or less. At the same time, student loan debt is at an all-time high, recently passing credit card debt in…

Maxed out: The Relationship between Credit Card Debt, Credit Card Distress and Grade Point Averages for College Students

ERIC Educational Resources Information Center

Smith, Temple Day

2011-01-01

Few students leave college with a plan for paying off their debt. Starting a career inundated with student loans and credit card debt burdens is a reality many college students face today. In the wake of graduation coming to terms with the consequences of credit card debt is stressful for many students. This dissertation observes the relationship…

Financially At-Risk College Students: An Exploratory Investigation of Student Loan Debt and Prioritization of Debt Repayment

ERIC Educational Resources Information Center

Pinto, Mary Beth; Mansfield, Phylis M.

2006-01-01

College students today face heavy student loan debt that is intensified by the amount of credit card debt they carry. This study provides a profile of financially at-risk students based on their credit card usage behavior. When compared to the non-financially at-risk students, those in the financially at-risk group were found to have higher…

31 CFR 285.5 - Centralized offset of Federal payments to collect nontax debts owed to the United States.

Code of Federal Regulations, 2010 CFR

2010-07-01

... to the United States. Debtor means a person who owes a debt to the United States. Delinquent or past... been made. Nothing in this section is intended to define whether a debt is delinquent or past-due for purposes other than offset under this section. Delinquent debt record means information about a past-due...

36 CFR 1011.11 - How will the Presidio Trust use tax refund offset to collect a debt?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false How will the Presidio Trust... PRESIDIO TRUST DEBT COLLECTION Procedures To Collect Presidio Trust Debts § 1011.11 How will the Presidio Trust use tax refund offset to collect a debt? (a) Tax refund offset. In most cases, the FMS uses the...

36 CFR 1011.13 - How will the Presidio Trust use administrative wage garnishment to collect a debt from a debtor's...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false How will the Presidio Trust... Parks, Forests, and Public Property PRESIDIO TRUST DEBT COLLECTION Procedures To Collect Presidio Trust Debts § 1011.13 How will the Presidio Trust use administrative wage garnishment to collect a debt from a...

36 CFR 1011.19 - Will the Presidio Trust issue a refund if money is erroneously collected on a debt?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Will the Presidio Trust issue... Public Property PRESIDIO TRUST DEBT COLLECTION Procedures To Collect Presidio Trust Debts § 1011.19 Will the Presidio Trust issue a refund if money is erroneously collected on a debt? The Presidio Trust will...

Medical student debt and major life choices other than specialty.

PubMed

Rohlfing, James; Navarro, Ryan; Maniya, Omar Z; Hughes, Byron D; Rogalsky, Derek K

2014-01-01

Background Median indebtedness at graduation is now more than $170,000 for graduates of US Medical Schools. Debate still exists as to whether higher debt levels influence students to choose high paying non-primary care specialties. Notably, no previous research on the topic has taken into account cost of attendance when constructing a debt model, nor has any research examined the non-career major life decisions that medical students face. Methods Medical students were surveyed using an anonymous electronic instrument developed for this study. The survey was delivered through a link included in a study email and students were recruited from school wide listservs and through snowball sampling (students were encouraged to share a link to the survey with other medical students). No incentives were offered for survey completion. Results Responses were recorded from 102 US Allopathic medical schools (n=3,032), with 22 institutions (11 public, 11 private) meeting inclusion criteria of 10% student body response proportion (n=1,846). Students with higher debt relative to their peers at their home institution reported higher frequencies of feeling callous towards others, were more likely to choose a specialty with a higher average annual income, were less likely to plan to practice in underserved locations, and were less likely to choose primary care specialties. Students with higher aggregate amounts of medical student loan debt were more likely to report high levels of stress from their educational debt, to delay getting married and to report disagreement that they would choose to become a physician again, if given the opportunity to revisit that choice. Increases in both aggregate and relative debt were associated with delaying having children, delaying buying a house, concerns about managing and paying back educational debt, and worrying that educational debt will influence one's specialty choice. Conclusions Medical student debt and particularly debt relative to peers at the same institution appears to influence the way that students approach major life choices like when to start a family, when to buy a home, and what specialty to choose. Future research should take into account cost of attendance when looking for the impact of medical student debt on major life choices.

Medical student debt and major life choices other than specialty.

PubMed

Rohlfing, James; Navarro, Ryan; Maniya, Omar Z; Hughes, Byron D; Rogalsky, Derek K

2014-01-01

Median indebtedness at graduation is now more than $170,000 for graduates of US Medical Schools. Debate still exists as to whether higher debt levels influence students to choose high paying non-primary care specialties. Notably, no previous research on the topic has taken into account cost of attendance when constructing a debt model, nor has any research examined the non-career major life decisions that medical students face. Medical students were surveyed using an anonymous electronic instrument developed for this study. The survey was delivered through a link included in a study email and students were recruited from school wide listservs and through snowball sampling (students were encouraged to share a link to the survey with other medical students). No incentives were offered for survey completion. Responses were recorded from 102 US Allopathic medical schools (n=3,032), with 22 institutions (11 public, 11 private) meeting inclusion criteria of 10% student body response proportion (n=1,846). Students with higher debt relative to their peers at their home institution reported higher frequencies of feeling callous towards others, were more likely to choose a specialty with a higher average annual income, were less likely to plan to practice in underserved locations, and were less likely to choose primary care specialties. Students with higher aggregate amounts of medical student loan debt were more likely to report high levels of stress from their educational debt, to delay getting married and to report disagreement that they would choose to become a physician again, if given the opportunity to revisit that choice. Increases in both aggregate and relative debt were associated with delaying having children, delaying buying a house, concerns about managing and paying back educational debt, and worrying that educational debt will influence one's specialty choice. Medical student debt and particularly debt relative to peers at the same institution appears to influence the way that students approach major life choices like when to start a family, when to buy a home, and what specialty to choose. Future research should take into account cost of attendance when looking for the impact of medical student debt on major life choices.

Medical student debt and major life choices other than specialty

PubMed Central

Rohlfing, James; Navarro, Ryan; Maniya, Omar Z.; Hughes, Byron D.; Rogalsky, Derek K.

2014-01-01

Background Median indebtedness at graduation is now more than $170,000 for graduates of US Medical Schools. Debate still exists as to whether higher debt levels influence students to choose high paying non-primary care specialties. Notably, no previous research on the topic has taken into account cost of attendance when constructing a debt model, nor has any research examined the non-career major life decisions that medical students face. Methods Medical students were surveyed using an anonymous electronic instrument developed for this study. The survey was delivered through a link included in a study email and students were recruited from school wide listservs and through snowball sampling (students were encouraged to share a link to the survey with other medical students). No incentives were offered for survey completion. Results Responses were recorded from 102 US Allopathic medical schools (n=3,032), with 22 institutions (11 public, 11 private) meeting inclusion criteria of 10% student body response proportion (n=1,846). Students with higher debt relative to their peers at their home institution reported higher frequencies of feeling callous towards others, were more likely to choose a specialty with a higher average annual income, were less likely to plan to practice in underserved locations, and were less likely to choose primary care specialties. Students with higher aggregate amounts of medical student loan debt were more likely to report high levels of stress from their educational debt, to delay getting married and to report disagreement that they would choose to become a physician again, if given the opportunity to revisit that choice. Increases in both aggregate and relative debt were associated with delaying having children, delaying buying a house, concerns about managing and paying back educational debt, and worrying that educational debt will influence one's specialty choice. Conclusions Medical student debt and particularly debt relative to peers at the same institution appears to influence the way that students approach major life choices like when to start a family, when to buy a home, and what specialty to choose. Future research should take into account cost of attendance when looking for the impact of medical student debt on major life choices. PMID:25391976

Struggle for space: viral extinction through competition for cells.

PubMed

Cuesta, José A; Aguirre, Jacobo; Capitán, José A; Manrubia, Susanna C

2011-01-14

The design of protocols to suppress the propagation of viral infections is an enduring enterprise, especially hindered by limited knowledge of the mechanisms leading to viral extinction. Here we report on infection extinction due to intraspecific competition to infect susceptible hosts. Beneficial mutations increase the production of viral progeny, while the host cell may develop defenses against infection. For an unlimited number of host cells, a feedback runaway coevolution between host resistance and progeny production occurs. However, physical space limits the advantage that the virus obtains from increasing offspring numbers; thus, infection clearance may result from an increase in host defenses beyond a finite threshold. Our results might be relevant to devise improved control strategies in environments with mobility constraints or different geometrical properties.

A cross-disciplinary assessment of student loans debt, financial support for study and career preferences upon graduation.

PubMed

Webster, Craig S; Ling, Christopher; Barrow, Mark; Poole, Phillippa; Henning, Marcus

2017-07-21

To explore relationships between student loans debt, financial support and career preferences upon graduation for all healthcare disciplines offered at the Faculty of Medical and Health Sciences, University of Auckland. The Faculty Tracking Project is a longitudinal study which invites students to complete a questionnaire at the beginning and end of their educational programmes, including questions on debt, financial support and career preference. Our analysis comprised three phases: (1) a descriptive analysis of data related to debt and financial support; (2) a principal component analysis in order to find related categories of career choice; and (3) logistic regression models to determine how career preference categories could be explained by either levels of student loans debt or financial support. Data from 2,405 participating students were included. Students in health sciences, nursing and pharmacy typically accrue levels of student loans debt of around $15,000 to $29,999, while optometry students accrue debt around $15,000 higher. Medical students show debt distributed around modes of $0 and $90,000 or more. All students typically access three sources of financial support during study. Career preferences at graduation reduced to four categories for all health disciplines. We found five significant effects, involving students in health sciences, medicine and pharmacy, relating the number of sources of financial support to the four categories of career preference. No significant effects were found related to level of student loans debt. Our results suggest that financial support is a more strongly determining factor in career choices than the level of student loans debt. The four-category framework for student career preferences appears to be a useful model for further research.

Geography of current and future global mammal extinction risk

PubMed Central

Shoemaker, Kevin T.; Weinstein, Ben; Costa, Gabriel C.; Brooks, Thomas M.; Ceballos, Gerardo; Radeloff, Volker C.; Rondinini, Carlo; Graham, Catherine H.

2017-01-01

Identifying which species are at greatest risk, what makes them vulnerable, and where they are distributed are central goals for conservation science. While knowledge of which factors influence extinction risk is increasingly available for some taxonomic groups, a deeper understanding of extinction correlates and the geography of risk remains lacking. Here, we develop a predictive random forest model using both geospatial and mammalian species’ trait data to uncover the statistical and geographic distributions of extinction correlates. We also explore how this geography of risk may change under a rapidly warming climate. We found distinctive macroecological relationships between species-level risk and extinction correlates, including the intrinsic biological traits of geographic range size, body size and taxonomy, and extrinsic geographic settings such as seasonality, habitat type, land use and human population density. Each extinction correlate exhibited ranges of values that were especially associated with risk, and the importance of different risk factors was not geographically uniform across the globe. We also found that about 10% of mammals not currently recognized as at-risk have biological traits and occur in environments that predispose them towards extinction. Southeast Asia had the most actually and potentially threatened species, underscoring the urgent need for conservation in this region. Additionally, nearly 40% of currently threatened species were predicted to experience rapid climate change at 0.5 km/year or more. Biological and environmental correlates of mammalian extinction risk exhibit distinct statistical and geographic distributions. These results provide insight into species-level patterns and processes underlying geographic variation in extinction risk. They also offer guidance for future conservation research focused on specific geographic regions, or evaluating the degree to which species-level patterns mirror spatial variation in the pressures faced by populations within the ranges of individual species. The added impacts from climate change may increase the susceptibility of at-risk species to extinction and expand the regions where mammals are most vulnerable globally. PMID:29145486

Large Diameter, Radiative Extinction Experiments with Decane Droplets in Microgravity

NASA Technical Reports Server (NTRS)

Easton, John; Tien, James; Dietrich, Daniel

1999-01-01

The extinction of a diffusion flame is of fundamental interest in combustion science. Linan, Law, and Chung and Law analytically and experimentally determined an extinction boundary in terms of droplet diameter and pressure for a single droplet due to Damkohler, or blowoff, extinction. More recently, other researchers demonstrated extinction due to finite rate kinetics in reduced gravity for free droplets of heptane. Chao modeled the effect of radiative heat loss on a quasi-steady spherically symmetric single droplet burning in the absence of buoyancy. They determined that for increasing droplet diameter, a second limit can be reached such that combustion is no longer possible. This second, larger droplet diameter limit arises due to radiative heat loss, which increases with increasing droplet and flame diameter. This increase in radiative heat loss arises due to an increase in the surface area of the flame. Recently, Marchese modeled fuel droplets with detailed chemistry and radiative effects, and compared the results to other work. The modeling also showed the importance of radiative loss and radiative extinction Experiments examined the behavior of a large droplet of decane burning in reduced gravity onboard the NASA Lewis DC-9 aircraft, but did not show a radiative extinction boundary due to g-jitter (Variations in gravitational level and direction) effects. Dietrich conducted experiments in the reduced gravity environment of the Space Shuttle. This work showed that the extinction diameter of methanol droplets increased when the initial diameter of the droplets was large (in this case, approximately 5 mm). Theoretical results agreed with these experimental results only when the theory included radiative effects . Radiative extinction was experimentally verified by Nayagam in a later Shuttle mission. The following work focuses on the combustion and extinction of a single fuel droplet. The goal is to experimentally determine a large droplet diameter limit that arises due to radiative heat loss from the flame to the surroundings.

Geography of current and future global mammal extinction risk.

PubMed

Davidson, Ana D; Shoemaker, Kevin T; Weinstein, Ben; Costa, Gabriel C; Brooks, Thomas M; Ceballos, Gerardo; Radeloff, Volker C; Rondinini, Carlo; Graham, Catherine H

2017-01-01

Identifying which species are at greatest risk, what makes them vulnerable, and where they are distributed are central goals for conservation science. While knowledge of which factors influence extinction risk is increasingly available for some taxonomic groups, a deeper understanding of extinction correlates and the geography of risk remains lacking. Here, we develop a predictive random forest model using both geospatial and mammalian species' trait data to uncover the statistical and geographic distributions of extinction correlates. We also explore how this geography of risk may change under a rapidly warming climate. We found distinctive macroecological relationships between species-level risk and extinction correlates, including the intrinsic biological traits of geographic range size, body size and taxonomy, and extrinsic geographic settings such as seasonality, habitat type, land use and human population density. Each extinction correlate exhibited ranges of values that were especially associated with risk, and the importance of different risk factors was not geographically uniform across the globe. We also found that about 10% of mammals not currently recognized as at-risk have biological traits and occur in environments that predispose them towards extinction. Southeast Asia had the most actually and potentially threatened species, underscoring the urgent need for conservation in this region. Additionally, nearly 40% of currently threatened species were predicted to experience rapid climate change at 0.5 km/year or more. Biological and environmental correlates of mammalian extinction risk exhibit distinct statistical and geographic distributions. These results provide insight into species-level patterns and processes underlying geographic variation in extinction risk. They also offer guidance for future conservation research focused on specific geographic regions, or evaluating the degree to which species-level patterns mirror spatial variation in the pressures faced by populations within the ranges of individual species. The added impacts from climate change may increase the susceptibility of at-risk species to extinction and expand the regions where mammals are most vulnerable globally.

Testing for a Debt-Threshold Effect on Output Growth.

PubMed

Lee, Sokbae; Park, Hyunmin; Seo, Myung Hwan; Shin, Youngki

2017-12-01

Using the Reinhart-Rogoff dataset, we find a debt threshold not around 90 per cent but around 30 per cent, above which the median real gross domestic product (GDP) growth falls abruptly. Our work is the first to formally test for threshold effects in the relationship between public debt and median real GDP growth. The null hypothesis of no threshold effect is rejected at the 5 per cent significance level for most cases. While we find no evidence of a threshold around 90 per cent, our findings from the post-war sample suggest that the debt threshold for economic growth may exist around a relatively small debt-to-GDP ratio of 30 per cent. Furthermore, countries with debt-to-GDP ratios above 30 per cent have GDP growth that is 1 percentage point lower at the median.

Student debt amongst junior doctors in New Zealand; part 1: quantity, distribution, and psychosocial impact.

PubMed

Moore, James; Gale, Jesse; Dew, Kevin; Davie, Gabrielle

2006-02-17

To quantify student debt owed by first-year house officers at graduation, and to describe the effects of student debt on their lives. A questionnaire was sent was to all 296 New Zealand-graduate first-year house officers practicing in New Zealand. The survey included questions on demographics, level of debt, student support received, repayment since graduation, psychosocial and financial impact of debt, and career intentions. The response rate was 53%. Ninety-two percent of respondents had some form of student debt, with 85% having a government student loan. The average total debt from all sources (excluding mortgages) at graduation was NZ65,206 dollars. Seventy-five percent of respondents owed more than 50,000 dollars and 13% had owed more than 100,000 dollars. Eighty-eight percent of respondents reported increased levels of stress as a result of their student loan, with 31% reporting that they worried about their student loan 'often' or 'always'. Eighty-three percent reported that their student loan had made it more difficult to save for their future, such as for a house deposit or for their retirement, and 42% stated that their student loan debt had influenced their decision whether to have children (or more children). Student debt has a major negative impact on the lives of house officers in New Zealand. These data provide a baseline for studying how changes in medical education affect junior doctors.

A retrospective analysis of the relationship between medical student debt and primary care practice in the United States.

PubMed

Phillips, Julie P; Petterson, Stephen M; Bazemore, Andrew W; Phillips, Robert L

2014-01-01

We undertook a study to reexamine the relationship between educational debt and primary care practice, accounting for the potentially confounding effect of medical student socioeconomic status. We performed retrospective multivariate analyses of data from 136,232 physicians who graduated from allopathic US medical schools between 1988 and 2000, obtained from the American Association of Medical Colleges Graduate Questionnaire, the American Medical Association Physician Masterfile, and other sources. Need-based loans were used as markers for socioeconomic status of physicians' families of origin. We examined 2 outcomes: primary care practice and family medicine practice in 2010. Physicians who graduated from public schools were most likely to practice primary care and family medicine at graduating educational debt levels of $50,000 to $100,000 (2010 dollars; P <.01). This relationship between debt and primary care practice persisted when physicians from different socioeconomic status groups, as approximated by loan type, were examined separately. At higher debt, graduates' odds of practicing primary care or family medicine declined. In contrast, private school graduates were not less likely to practice primary care or family medicine as debt levels increased. High educational debt deters graduates of public medical schools from choosing primary care, but does not appear to influence private school graduates in the same way. Students from relatively lower income families are more strongly influenced by debt. Reducing debt of selected medical students may be effective in promoting a larger primary care physician workforce. © 2014 Annals of Family Medicine, Inc.

A Retrospective Analysis of the Relationship Between Medical Student Debt and Primary Care Practice in the United States

PubMed Central

Phillips, Julie P.; Petterson, Stephen M.; Bazemore, Andrew W.; Phillips, Robert L.

2014-01-01

PURPOSE We undertook a study to reexamine the relationship between educational debt and primary care practice, accounting for the potentially confounding effect of medical student socioeconomic status. METHODS We performed retrospective multivariate analyses of data from 136,232 physicians who graduated from allopathic US medical schools between 1988 and 2000, obtained from the American Association of Medical Colleges Graduate Questionnaire, the American Medical Association Physician Masterfile, and other sources. Need-based loans were used as markers for socioeconomic status of physicians’ families of origin. We examined 2 outcomes: primary care practice and family medicine practice in 2010. RESULTS Physicians who graduated from public schools were most likely to practice primary care and family medicine at graduating educational debt levels of $50,000 to $100,000 (2010 dollars; P <.01). This relationship between debt and primary care practice persisted when physicians from different socioeconomic status groups, as approximated by loan type, were examined separately. At higher debt, graduates’ odds of practicing primary care or family medicine declined. In contrast, private school graduates were not less likely to practice primary care or family medicine as debt levels increased. CONCLUSIONS High educational debt deters graduates of public medical schools from choosing primary care, but does not appear to influence private school graduates in the same way. Students from relatively lower income families are more strongly influenced by debt. Reducing debt of selected medical students may be effective in promoting a larger primary care physician workforce. PMID:25384816

Compound-specific carbon isotopes from Earth’s largest flood basalt eruptions directly linked to the end-Triassic mass extinction

PubMed Central

Whiteside, Jessica H.; Olsen, Paul E.; Eglinton, Timothy; Brookfield, Michael E.; Sambrotto, Raymond N.

2010-01-01

A leading hypothesis explaining Phanerozoic mass extinctions and associated carbon isotopic anomalies is the emission of greenhouse, other gases, and aerosols caused by eruptions of continental flood basalt provinces. However, the necessary serial relationship between these eruptions, isotopic excursions, and extinctions has never been tested in geological sections preserving all three records. The end-Triassic extinction (ETE) at 201.4 Ma is among the largest of these extinctions and is tied to a large negative carbon isotope excursion, reflecting perturbations of the carbon cycle including a transient increase in CO2. The cause of the ETE has been inferred to be the eruption of the giant Central Atlantic magmatic province (CAMP). Here, we show that carbon isotopes of leaf wax derived lipids (n-alkanes), wood, and total organic carbon from two orbitally paced lacustrine sections interbedded with the CAMP in eastern North America show similar excursions to those seen in the mostly marine St. Audrie’s Bay section in England. Based on these results, the ETE began synchronously in marine and terrestrial environments slightly before the oldest basalts in eastern North America but simultaneous with the eruption of the oldest flows in Morocco, a CO2 super greenhouse, and marine biocalcification crisis. Because the temporal relationship between CAMP eruptions, mass extinction, and the carbon isotopic excursions are shown in the same place, this is the strongest case for a volcanic cause of a mass extinction to date. PMID:20308590

Measurement of aerosol optical properties by cw cavity enhanced spectroscopy

NASA Astrophysics Data System (ADS)

Jie, Guo; Ye, Shan-Shan; Yang, Xiao; Han, Ye-Xing; Tang, Huai-Wu; Yu, Zhi-Wei

2016-10-01

The CAPS (Cavity Attenuated Phase shift Spectroscopy) system, which detects the extinction coefficients within a 10 nm bandpass centered at 532 nm, comprises a green LED with center wavelength in 532nm, a resonant optical cavity (36 cm length), a Photo Multiplier Tube detector, and a lock in amplifier. The square wave modulated light from the LED passes through the optical cavity and is detected as a distorted waveform which is characterized by a phase shift with respect to the initial modulation. Extinction coefficients are determined from changes in the phase shift of the distorted waveform of the square wave modulated LED light that is transmitted through the optical cavity. The performance of the CAPS system was evaluated by using measurements of the stability and response of the system. The minima ( 0.1 Mm-1) in the Allan plots show the optimum average time ( 100s) for optimum detection performance of the CAPS system. In the paper, it illustrates that extinction coefficient was correlated with PM2.5 mass (0.91). These figures indicate that this method has the potential to become one of the most sensitive on-line analytical techniques for extinction coefficient detection. This work aims to provide an initial validation of the CAPS extinction monitor in laboratory and field environments. Our initial results presented in this paper show that the CAPS extinction monitor is capable of providing state-of-the-art performance while dramatically reducing the complexity of optical instrumentation for directly measuring the extinction coefficients.

17 CFR 240.3a12-11 - Exemption from sections 8(a), 14(a), 14(b), and 14(c) for debt securities listed on a national...

Code of Federal Regulations, 2010 CFR

2010-04-01

...), 14(a), 14(b), and 14(c) for debt securities listed on a national securities exchange. 240.3a12-11... 14(c) for debt securities listed on a national securities exchange. (a) Debt securities that are listed for trading on a national securities exchange shall be exempt from the restrictions on borrowing...

Out of the Nest and into the Red: Three Essays on Debt in Young Adulthood

ERIC Educational Resources Information Center

Houle, Jason N.

2011-01-01

The Great Recession of 2008 and rising costs of college have stoked popular and scholarly concern about young adult debt. Debt plays an important role in the lives of young people as they make the transition to adulthood, but little research has been conducted on the topic. This dissertation sheds light on the role of debt in the lives of young…

Can Profit Policy and Contract Incentives Improve Defense Contract Outcomes?

DTIC Science & Technology

2009-02-01

required by investors. The weighted average cost of capital ( WACC ) is the standard financial statistic that weights the returns demanded by investors that...hold equity and investors that hold debt.6 Like FCFROIC, WACC is expressed as a percentage. Consequently, it is possible to compare these two...contractors include Lockheed, Raytheon, Northrop Grumman, and General Dynamics. 6 Mathematically, WACC = Debt/(Debt + Equity) × Debt Cost × (1-Tax Rate

Cascades in multiplex financial networks with debts of different seniority

NASA Astrophysics Data System (ADS)

Brummitt, Charles D.; Kobayashi, Teruyoshi

2015-06-01

The seniority of debt, which determines the order in which a bankrupt institution repays its debts, is an important and sometimes contentious feature of financial crises, yet its impact on systemwide stability is not well understood. We capture seniority of debt in a multiplex network, a graph of nodes connected by multiple types of edges. Here an edge between banks denotes a debt contract of a certain level of seniority. Next we study cascading default. There exist multiple kinds of bankruptcy, indexed by the highest level of seniority at which a bank cannot repay all its debts. Self-interested banks would prefer that all their loans be made at the most senior level. However, mixing debts of different seniority levels makes the system more stable in that it shrinks the set of network densities for which bankruptcies spread widely. We compute the optimal ratio of senior to junior debts, which we call the optimal seniority ratio, for two uncorrelated Erdős-Rényi networks. If institutions erode their buffer against insolvency, then this optimal seniority ratio rises; in other words, if default thresholds fall, then more loans should be senior. We generalize the analytical results to arbitrarily many levels of seniority and to heavy-tailed degree distributions.