The relationship between annual predicted future population growth rates and elderly suicide rates

Environmental determinists predict that people move away from places experiencing frequent weather hazards, yet some of these areas have rapidly growing populations. This analysis examines the relationship between weather events and population change in all U.S. counties that experienced hurricanes and tropical storms between 1980 and 2012. Our database allows for more generalizable conclusions by accounting for heterogeneity in current and past hurricane events and losses and past population trends. We find that hurricanes and tropical storms affect future population growth only in counties with growing, high-density populations, which are only 2 percent of all counties. In those counties, current year hurricane events and related losses suppress future population growth, although cumulative hurricane-related losses actually elevate population growth. Low-density counties and counties with stable or declining populations experience no effect of these weather events. Our analysis provides a methodologically informed explanation for contradictory findings in prior studies.

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Relationship between body size and population growth rate in two opportunistic polychaetes

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315402005647 ◽

2002 ◽

Vol 82 (3) ◽

pp. 403-408 ◽

Cited By ~ 6

Author(s):

D. Prevedelli ◽

R. Simonini

Keyword(s):

Growth Rate ◽

Body Size ◽

Sex Ratio ◽

Population Growth ◽

Growth Rates ◽

Life Histories ◽

Population Growth Rate ◽

Population Growth Rates ◽

The Relationship ◽

Dinophilus Gyrociliatus

The relationship between body size and population growth rate λ has been studied in two species of opportunistic polychaetes, Dinophilus gyrociliatus and Ophryotrocha labronica, which colonize harbour environments. These species exhibit a semi-continuous iteroparous reproductive strategy, are phylogenetically closely-related but differ in body size and in some aspects of their sexuality. Ophryotrocha labronica is about 4 mm in body length, displays only slight sexual dimorphism and its sex ratio is biased towards the female sex in the ratio 2:1. Dinophilus gyrociliatus is about 1 mm in length, the males are extremely small and the sex ratio is strongly biased (3:1) in favour of the females. In spite of the considerable differences in all traits of their life histories and in many demographic parameters, the growth rates of the two populations are very similar. The analyses carried out have shown that the rapid attainment of sexual maturity of D. gyrociliatus gives it an advantage that offsets the greater fecundity of O. labronica. It is very likely that the reproductive peculiarities of D. gyrociliatus help to raise the population growth rates. The ‘saving’ on the male sex achieved both by the shift of the sex ratio in favour of the females and by the reduction in the males' body size would appear to enable D. gyrociliatus to grow at the same rate as O. labronica, a larger and more fecund species.

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A replication of the curvilinear relationship between population growth and elderly suicide rates in a cross-national study

International Psychogeriatrics ◽

10.1017/s1041610209991451 ◽

2009 ◽

Vol 22 (2) ◽

pp. 337-338 ◽

Cited By ~ 2

Author(s):

Ajit Shah

Keyword(s):

Population Growth ◽

The Elderly ◽

Quadratic Equation ◽

National Study ◽

Curvilinear Relationship ◽

Population Growth Rates ◽

Suicide Rates ◽

Elderly Suicide ◽

Cross National Study ◽

Cross National

A curvilinear (U-shaped) relationship between population growth rates and elderly suicide rates fitting the quadratic equation y = a + bx + cx2 (where y is the elderly suicide rate, x is the population growth rate and a, b and c are constants) has been reported (Shah, 2009a). A theoretical model with three sequential stages incorporating population growth, elderly population size, the proportion of elderly in the general population, life expectancy and birth rates has been proposed to explain the findings (Shah, 2009a).

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A Study of the Relationship Between Attitudes Towards World Population Growth and USA Population Growth

Journal of Biosocial Science ◽

10.1017/s0021932000008944 ◽

1973 ◽

Vol 5 (1) ◽

pp. 61-69

Author(s):

Larry D. Barnett

Keyword(s):

Growth Rate ◽

Population Growth ◽

Growth Rates ◽

World Population ◽

Population Growth Rates ◽

World Population Growth ◽

The Us ◽

The World ◽

The Relationship ◽

Public Opinion Polls

In the fall of 1965 and again in the fall of 1967, The Population Council sponsored nationwide public opinion polls in which questions were asked regarding whether the world and US population growth rates constituted serious problems. Both polls found the proportion of respondents viewing the world growth rate as serious (62% in 1965, 69% in 1967) to be higher than the proportion viewing the US rate as serious (54% in 1965 and 1967) (Kantner, 1968). Thus, attitudes towards world population growth and US population growth appear to be potentially independent of and not necessarily congruent with one another, but to date no examination has been made of their relationship. It is the purpose of the present study: (1) to determine the incidence of each possible combination of views towards the world and US population growth rates, and (2) to determine how individuals with a particular attitude towards one growth rate distribute themselves in terms of attitudes towards the other rate.

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The relationship between population growth and elderly suicide rates: a cross-national study

International Psychogeriatrics ◽

10.1017/s1041610208007953 ◽

2008 ◽

Vol 21 (02) ◽

pp. 379 ◽

Cited By ~ 7

Author(s):

Ajit Shah

Keyword(s):

Population Growth ◽

National Study ◽

Suicide Rates ◽

Elderly Suicide ◽

Cross National Study ◽

The Relationship ◽

Cross National

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Nonlinear averaging of thermal experience predicts population growth rates in a thermally variable environment

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2018.1076 ◽

2018 ◽

Vol 285 (1886) ◽

pp. 20181076 ◽

Cited By ~ 24

Author(s):

Joey R. Bernhardt ◽

Jennifer M. Sunday ◽

Patrick L. Thompson ◽

Mary I. O'Connor

Keyword(s):

Population Growth ◽

Growth Rates ◽

Critical Temperatures ◽

Variable Environment ◽

Population Growth Rates ◽

Thermal Environments ◽

Performance Curves ◽

Thermal Regimes ◽

Future Population ◽

Averaging Techniques

As thermal regimes change worldwide, projections of future population and species persistence often require estimates of how population growth rates depend on temperature. These projections rarely account for how temporal variation in temperature can systematically modify growth rates relative to projections based on constant temperatures. Here, we tested the hypothesis that time-averaged population growth rates in fluctuating thermal environments differ from growth rates in constant conditions as a consequence of Jensen's inequality, and that the thermal performance curves (TPCs) describing population growth in fluctuating environments can be predicted quantitatively based on TPCs generated in constant laboratory conditions. With experimental populations of the green alga Tetraselmis tetrahele , we show that nonlinear averaging techniques accurately predicted increased as well as decreased population growth rates in fluctuating thermal regimes relative to constant thermal regimes. We extrapolate from these results to project critical temperatures for population growth and persistence of 89 phytoplankton species in naturally variable thermal environments. These results advance our ability to predict population dynamics in the context of global change.

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The relationship of variable antigen expression and population growth rates inTrypanosoma brucei

Zeitschrift für Parasitenkunde Parasitology Research ◽

10.1007/bf00931517 ◽

1992 ◽

Vol 78 (8) ◽

pp. 661-664 ◽

Cited By ~ 10

Author(s):

N. Aslam ◽

C. M. R. Turner

Keyword(s):

Population Growth ◽

Growth Rates ◽

Antigen Expression ◽

Population Growth Rates ◽

Variable Antigen ◽

Relationship Of ◽

The Relationship

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Nonlinear averaging of thermal experience predicts population growth rates in a thermally variable environment

10.1101/247908 ◽

2018 ◽

Cited By ~ 1

Author(s):

Joey R. Bernhardt ◽

Jennifer M. Sunday ◽

Patrick L. Thompson ◽

Mary I. O’Connor

Keyword(s):

Population Growth ◽

Growth Rates ◽

Critical Temperatures ◽

Variable Environment ◽

Population Growth Rates ◽

Thermal Environments ◽

Performance Curves ◽

Thermal Regimes ◽

Future Population ◽

Averaging Techniques

AbstractAs thermal regimes change worldwide, projections of future population and species persistence often require estimates of how population growth rates depend on temperature. These projections rarely account for how temporal variation in temperature can systematically modify growth rates relative to projections based on constant temperatures. Here, we tested the hypothesis that population growth rates in fluctuating thermal environments differ from growth rates in constant conditions, and that the differing thermal performance curves (TPCs) can be predicted quantitatively. With experimental populations of the green alga Tetraselmis tetrahele, we show that nonlinear averaging techniques accurately predicted increased as well as decreased population growth rates in fluctuating thermal regimes relative to constant thermal regimes. We extrapolate from these results to project critical temperatures for population growth and persistence of 89 phytoplankton species in naturally variable thermal environments. These results advance our ability to predict population dynamics in the context of global change.

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