scholarly journals Adaptive Bet-Hedging Revisited: Considerations of Risk and Time Horizon

2020 ◽  
Vol 82 (4) ◽  
Author(s):  
Omri Tal ◽  
Tat Dat Tran
Keyword(s):  
Time Horizon ◽  
Extinction Risk ◽  
Pure Strategy ◽  
Bet Hedging ◽  
Average Growth ◽  
The Face ◽  
Game Theoretic ◽  
Payoff Functions ◽  
Finite Time Horizon

Abstract Models of adaptive bet-hedging commonly adopt insights from Kelly’s famous work on optimal gambling strategies and the financial value of information. In particular, such models seek evolutionary solutions that maximize long-term average growth rate of lineages, even in the face of highly stochastic growth trajectories. Here, we argue for extensive departures from the standard approach to better account for evolutionary contingencies. Crucially, we incorporate considerations of volatility minimization, motivated by interim extinction risk in finite populations, within a finite time horizon approach to growth maximization. We find that a game-theoretic competitive optimality approach best captures these additional constraints and derive the equilibria solutions under straightforward fitness payoff functions and extinction risks. We show that for both maximal growth and minimal time relative payoffs, the log-optimal strategy is a unique pure strategy symmetric equilibrium, invariant with evolutionary time horizon and robust to low extinction risks.

scholarly journals Adaptive Bet-Hedging Revisited: Considerations of Risk and Time Horizon

2019 ◽  
Author(s):  
Omri Tal ◽  
Tat Dat Tran
Keyword(s):  
Time Horizon ◽  
Extinction Risk ◽  
Bet Hedging ◽  
Average Growth ◽  
The Face ◽  
Game Theoretic ◽  
Payoff Functions ◽  
Finite Time Horizon ◽  
Additional Constraints

AbstractModels of adaptive bet-hedging commonly adopt insights from Kelly’s famous work on optimal gambling strategies and the financial value of information. In particular, such models seek evolutionary solutions that maximize long term average growth rate of lineages, even in the face of highly stochastic growth trajectories. Here, we argue for extensive departures from the standard approach to better account for evolutionary contingencies. Crucially, we incorporate considerations of volatility minimization, motivated by interim extinction risk in finite populations, within a finite time horizon approach to growth maximization. We find that a game-theoretic competitive-optimality approach best captures these additional constraints and derive the equilibria solutions under various fitness payoff functions.

The Prester John Test: a Rejoinder

1982 ◽  
Vol 20 (3) ◽  
pp. 520-521
Author(s):  
John M. Cohen
Keyword(s):  
Food Production ◽  
Time Horizon ◽  
Time Perspective ◽  
The Face ◽  
Over Time ◽  
The Revolution

The purpose of my December 1980 Africana note was to identify two major problems in the rapidly growing literature on the Ethiopian revolution: (1) the failure to honour the academic obligation to be exhaustive in the research enterprise; and (2) the tendency of students of the revolution to draw doubtful long-term conclustions on the basis of a brief time-horizon. To illustrate these points I used Peter Koehn's citations on food production and the conclusions he drew from them. Briefly, I noted that he had overlooked at least one important set of data and reached a conclusion that did not hold up over time. The references to new sources in both my note and the reply by Koehn and Brian D'Silva support my argument, for we have now located important, additional studies on production and rainfall, and Koehn has now altered and expanded his conclusions in the face of evidence from a longer time-perspective.

Challenges, Concerns, and Perspectives for Poland's Energy Transition during Global COVID-19 Pandemic

2020 ◽  
Vol 1 (2) ◽  
pp. 169-173
Author(s):  
Andrzej Lorkowski ◽  
Robert Jeszke
Keyword(s):  
Internal Energy ◽  
Energy Transition ◽  
Energy Transformation ◽  
Modern Times ◽  
Current Discussion ◽  
The Face ◽  
National Governments ◽  
The Eu ◽  
At Home

The whole world is currently struggling with one of the most disastrous pandemics to hit in modern times – Covid-19. Individual national governments, the WHO and worldwide media organisations are appealing for humanity to universally stay at home, to limit contact and to stay safe in the ongoing fight against this unseen threat. Economists are concerned about the devastating effect this will have on the markets and possible outcomes. One of the countries suffering from potential destruction of this situation is Poland. In this article we will explain how difficult internal energy transformation is, considering the long-term crisis associated with the extraction and usage of coal, the European Green Deal and current discussion on increasing the EU 2030 climate ambitions. In the face of an ongoing pandemic, the situation becomes even more challenging with each passing day.

Antiretroviral Treatment-Associated Labia Majora Lipohypertrophy: A Rare Case and Plastic Surgical Treatment Options

2017 ◽  
Vol 2 (1) ◽  
pp. 43
Author(s):  
Akmal Hisham ◽  
Devananthan Ilenghoven ◽  
Wan Syazli Wan Ahmad Kamal ◽  
Salina Ibrahim ◽  
Shah Jumaat Mohd Yussof
Keyword(s):  
Highly Active Antiretroviral Therapy ◽  
Daily Living ◽  
Treatment Options ◽  
Hiv Positive ◽  
Highly Active ◽  
Labia Majora ◽  
The Face ◽  
Central Fat

The emergence of highly active antiretroviral therapy (HAART) has revolutionized the prognosis of HIV-infected patients. However, the extended use of HAART is associated with a disfiguring complication termed lipodystrophy, a disorder of body fat maldistribution causing peripheral fat loss (lipoatrophy) and central fat accumulation (lipohypertrophy). Lipoatrophy commonly affects the face, legs, buttocks and arm, whilst lipohypertrophy frequently favours the abdomen, breast and dorsocervical region. To our knowledge, we present only the second documented case in the literature of a labia majora lipohypertrophy in a HIV-positive patient receiving long-term HAART. The severity of labial abnormality caused significant physical and functional morbidities. Labiaplasty with dermolipectomy of the labia majora and excisional lipectomy of the mons pubis was successfully performed. At a 6-month follow-up, patient had no recurrence with resolution of symptoms and resumption of normal activities of daily living (ADL).

Populist Parties in Lithuania: Curious Case of Party Order and Justice and its Leadership

2019 ◽  
Vol 7 (1) ◽  
pp. 120-137 ◽  
Author(s):  
Mindaugas Jurkynas
Keyword(s):  
Party System ◽  
Leadership Selection ◽  
Political Careers ◽  
New Parties ◽  
Selection Rules ◽  
Electoral Support ◽  
The Face

AbstractThe article discusses conceptualisation of populism, Lithuania’s party system and electoral dynamics and their relation to the sustainability of populist parties. Special attention is given to Party Order and Justice, a former populist and protest party, and its leadership, namely to the issues related to scope and competencies of a leader’s intra-partisan power, leadership selection rules and history, development of leaders’ political careers and their electoral activity. The L ithuanian party system now exhibits moderate fragmentation without centrifugal tendencies. Voter volatility is still relatively high, yet the share of new parties has dropped to zero. The protest and populist parties in Lithuania went into the margins of political establishment. Popularity of the Order and Justice party has long been connected to the formerly impeached president Rolandas Paksas. His long-term leadership in the face of plummeting electoral support and an emphasis on his political martyrdom resulted in poor electoral performances, ensuing internal squabbles and his departure. Party Order and Justice’s internal regulations, however, remained favourable to strong leadership.

The Many Faces of Socioeconomic Change

2017 ◽  
Author(s):  
John Toye
Keyword(s):  
Socioeconomic Development ◽  
Adam Smith ◽  
First Century ◽  
Social Progress ◽  
Long Time ◽  
The Face ◽  
Scientific Expertise ◽  
The Many ◽  
Century Development

This book provides a survey of different ways in which economic sociocultural and political aspects of human progress have been studied since the time of Adam Smith. Inevitably, over such a long time span, it has been necessary to concentrate on highlighting the most significant contributions, rather than attempting an exhaustive treatment. The aim has been to bring into focus an outline of the main long-term changes in the way that socioeconomic development has been envisaged. The argument presented is that the idea of socioeconomic development emerged with the creation of grand evolutionary sequences of social progress that were the products of Enlightenment and mid-Victorian thinkers. By the middle of the twentieth century, when interest in the accelerating development gave the topic a new impetus, its scope narrowed to a set of economically based strategies. After 1960, however, faith in such strategies began to wane, in the face of indifferent results and general faltering of confidence in economists’ boasts of scientific expertise. In the twenty-first century, development research is being pursued using a research method that generates disconnected results. As a result, it seems unlikely that any grand narrative will be created in the future and that neo-liberalism will be the last of this particular kind of socioeconomic theory.

Population fragmentation causes inadequate gene flow and increases extinction risk

2017 ◽  
Author(s):  
Richard Frankham ◽  
Jonathan D. Ballou ◽  
Katherine Ralls ◽  
Mark D. B. Eldridge ◽  
Michele R. Dudash ◽  
...  
Keyword(s):  
Gene Flow ◽  
Extinction Risk ◽  
Random Mating ◽  
Large Population ◽  
Isolated Population ◽  
Population Fragmentation ◽  
Single Population ◽  
Total Size ◽  
Limited Gene Flow

Most species now have fragmented distributions, often with adverse genetic consequences. The genetic impacts of population fragmentation depend critically upon gene flow among fragments and their effective sizes. Fragmentation with cessation of gene flow is highly harmful in the long term, leading to greater inbreeding, increased loss of genetic diversity, decreased likelihood of evolutionary adaptation and elevated extinction risk, when compared to a single population of the same total size. The consequences of fragmentation with limited gene flow typically lie between those for a large population with random mating and isolated population fragments with no gene flow.

scholarly journals Are asylum seekers more likely to work with more inclusive labor market access regulations?

2019 ◽  
Vol 155 (1) ◽  
Author(s):  
Michaela Slotwinski ◽  
Alois Stutzer ◽  
Roman Uhlig
Keyword(s):  
Labor Market ◽  
Asylum Seekers ◽  
Market Access ◽  
Initial Period ◽  
Early Integration ◽  
Labor Market Policies ◽  
The Face ◽  
Labor Market Access ◽  
The One

Abstract In the face of recent refugee migration, early integration of asylum seekers into the labor market has been proposed as an important mechanism for easing their economic and social lot in the short as well as in the long term. However, little is known about the policies that foster or hamper their participation in the labor market, in particular during the important initial period of their stay in the host country. In order to evaluate whether inclusive labor market policies increase the labor market participation of asylum seekers, we exploit the variation in asylum policies in Swiss cantons to which asylum seekers are as good as randomly allocated. During our study period from 2011 to 2014, the employment rate among asylum seekers varied between 0 and 30.2% across cantons. Our results indicate that labor market access regulations are responsible for a substantial proportion of these differences, in which an inclusive regime increases participation by 11 percentage points. The marginal effects are larger for asylum seekers who speak a language that is linguistically close to the one in their host canton. Summary Inclusive labor market access regulations substantially increase the employment chances of asylum seekers, in particular if the language distance is short.

scholarly journals Vulnerable Older Adults in Disasters: Effects of Hurricane Irma on Nursing Homes and Assisted Living

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 733-734
Author(s):  
Lindsay Peterson ◽  
David Dosa ◽  
Patricia D’Antonio
Keyword(s):  
Older Adults ◽  
Assisted Living ◽  
Gulf Coast ◽  
Secondary Data ◽  
Morbidity And Mortality ◽  
Term Care ◽  
The Face ◽  
Qualitative Methodologies ◽  
Hurricane Irma

Abstract Preparedness of residents in long-term care (LTC) in the face of hurricane emergencies is a contested and largely unanswered question. Our prior work involving the U.S. Gulf Coast hurricanes of 2005-08 showed that exposure to various storms on nursing home (NH) residents resulted in significantly more deaths than reported by health care officials. This work also highlighted that evacuation of NH residents, compared to sheltering in place, was independently associated with morbidity and mortality. Hurricane Irma struck Florida on Sept. 10, 2017, prompting the evacuation of thousands of NH and assisted living community (ALC) residents. This symposium will discuss the effects of Hurricane Irma on vulnerable older adults residing in NHs and ALCs using mixed quantitative and qualitative methodologies. The first presentation will discuss morbidity and mortality of NH residents exposed to Hurricane Irma and will stratify by long stay/short stay status and hospice enrollment. The second presentation will discuss improvements and continued barriers to NH preparedness based on interviews with 30 administrators following Hurricane Irma. Using a novel methodology to identify residents of ALCs using secondary data sources, the third presentation will document AL resident morbidity and mortality risk following Hurricane Irma. The final presentation will highlight results of interviews with 70 stakeholders from small and large ALCs concerning the hurricane experiences of residents, including those with dementia. This symposium offers a multi-faceted view of a disaster’s effects on LTC residents across Florida, including novel data from the NH environment and lesser-examined ALCs.

Sign in / Sign up

Export Citation Format

Share Document