WorldWideScience

Sample records for young life history

  1. Life History Strategy and Young Adult Substance Use

    OpenAIRE

    George B. Richardson; Ching-Chen Chen; Chia-Liang Dai; Patrick H. Hardesty; Christopher M. Swoboda

    2014-01-01

    This study tested whether life history strategy (LHS) and its intergenerational transmission could explain young adult use of common psychoactive substances. We tested a sequential structural equation model using data from the National Longitudinal Survey of Youth. During young adulthood, fast LHS explained 61% of the variance in overall liability for substance use. Faster parent LHS predicted poorer health and lesser alcohol use, greater neuroticism and cigarette smoking, but did not predict...

  2. Life history strategy and young adult substance use.

    Science.gov (United States)

    Richardson, George B; Chen, Ching-Chen; Dai, Chia-Liang; Swoboda, Christopher M

    2014-11-03

    This study tested whether life history strategy (LHS) and its intergenerational transmission could explain young adult use of common psychoactive substances. We tested a sequential structural equation model using data from the National Longitudinal Survey of Youth. During young adulthood, fast LHS explained 61% of the variance in overall liability for substance use. Faster parent LHS predicted poorer health and lesser alcohol use, greater neuroticism and cigarette smoking, but did not predict fast LHS or overall liability for substance use among young adults. Young adult neuroticism was independent of substance use controlling for fast LHS. The surprising finding of independence between parent and child LHS casts some uncertainty upon the identity of the parent and child LHS variables. Fast LHS may be the primary driver of young adult use of common psychoactive substances. However, it is possible that the young adult fast LHS variable is better defined as young adult mating competition. We discuss our findings in depth, chart out some intriguing new directions for life history research that may clarify the dimensionality of LHS and its mediation of the intergenerational transmission of substance use, and discuss implications for substance abuse prevention and treatment.

  3. Life History Strategy and Young Adult Substance Use

    Directory of Open Access Journals (Sweden)

    George B. Richardson

    2014-04-01

    Full Text Available This study tested whether life history strategy (LHS and its intergenerational transmission could explain young adult use of common psychoactive substances. We tested a sequential structural equation model using data from the National Longitudinal Survey of Youth. During young adulthood, fast LHS explained 61% of the variance in overall liability for substance use. Faster parent LHS predicted poorer health and lesser alcohol use, greater neuroticism and cigarette smoking, but did not predict fast LHS or overall liability for substance use among young adults. Young adult neuroticism was independent of substance use controlling for fast LHS. The surprising finding of independence between parent and child LHS casts some uncertainty upon the identity of the parent and child LHS variables. Fast LHS may be the primary driver of young adult use of common psychoactive substances. However, it is possible that the young adult fast LHS variable is better defined as young adult mating competition. We discuss our findings in depth, chart out some intriguing new directions for life history research that may clarify the dimensionality of LHS and its mediation of the intergenerational transmission of substance use, and discuss implications for substance abuse prevention and treatment.

  4. Young adult patients with a history of pediatric disease: impact on course of life and transition into adulthood

    NARCIS (Netherlands)

    Stam, Heleen; Hartman, Esther E.; Deurloo, Jacqueline A.; Groothoff, Jaap; Grootenhuis, Martha A.

    2006-01-01

    PURPOSE: To assess the course of life of young adults who grew up with a chronic or life-threatening disease, and to compare their course of life with that of peers from the general population. Optimal transition from pediatric to adult health care requires knowledge of the psychosocial history of

  5. Vision-related quality of life assessment using the NEI-VFQ-25 in adolescents and young adults with a history of congenital cataract.

    LENUS (Irish Health Repository)

    Kirwan, Caitriona

    2013-07-22

    To assess vision-specific health-related quality of life in adolescents and young adults with a history of congenital cataract using the National Eye Institute 25-item Visual Function Questionnaire (NEI-VFQ-25).

  6. Life History Approach

    DEFF Research Database (Denmark)

    Olesen, Henning Salling

    2015-01-01

    as in everyday life. Life histories represent lived lives past, present and anticipated future. As such they are interpretations of individuals’ experiences of the way in which societal dynamics take place in the individual body and mind, either by the individual him/herself or by another biographer. The Life...... History approach was developing from interpreting autobiographical and later certain other forms of language interactive material as moments of life history, i.e. it is basically a hermeneutic approach. Talking about a psycho-societal approach indicates the ambition of attacking the dichotomy...... of the social and the psychic, both in the interpretation procedure and in some main theoretical understandings of language, body and mind. My article will present the reflections on the use of life history based methodology in learning and education research as a kind of learning story of research work....

  7. Life-history interviews

    DEFF Research Database (Denmark)

    Adriansen, Hanne Kirstine

    2010-01-01

    in qualitative interviews. I first presented the paper on a conference on life history research at Karlstad University in November 2010. My main purpose was to establish whether a paper discussing the use of time line interviews should be placed in the context of a life history research. The valuable comments......My first encounter with life history research was during my Ph.D. research. This concerned a multi-method study of nomadic mobility in Senegal. One method stood out as yielding the most interesting and in-depth data: life story interviews using a time line. I made interviews with the head...... of the nomadic households and during these I came to understand the use of mobility in a complex context of continuity and change, identity and belonging in the Fulani community. Time line interviews became one of my favourite tool in the years to follow, a tool used both for my research in various settings...

  8. Life History and Identity

    Science.gov (United States)

    Tierney, William G.

    2013-01-01

    This article uses the life history method to chronicle the challenges of a low-income, first-generation student en route to college. The paper addresses three questions: how Manuel navigates college and related topics such as roommates, family, and money; how he creates social networks; and how he works with adults such as teachers and…

  9. Human Life History Strategies.

    Science.gov (United States)

    Chua, Kristine J; Lukaszewski, Aaron W; Grant, DeMond M; Sng, Oliver

    2017-01-01

    Human life history (LH) strategies are theoretically regulated by developmental exposure to environmental cues that ancestrally predicted LH-relevant world states (e.g., risk of morbidity-mortality). Recent modeling work has raised the question of whether the association of childhood family factors with adult LH variation arises via (i) direct sampling of external environmental cues during development and/or (ii) calibration of LH strategies to internal somatic condition (i.e., health), which itself reflects exposure to variably favorable environments. The present research tested between these possibilities through three online surveys involving a total of over 26,000 participants. Participants completed questionnaires assessing components of self-reported environmental harshness (i.e., socioeconomic status, family neglect, and neighborhood crime), health status, and various LH-related psychological and behavioral phenotypes (e.g., mating strategies, paranoia, and anxiety), modeled as a unidimensional latent variable. Structural equation models suggested that exposure to harsh ecologies had direct effects on latent LH strategy as well as indirect effects on latent LH strategy mediated via health status. These findings suggest that human LH strategies may be calibrated to both external and internal cues and that such calibrational effects manifest in a wide range of psychological and behavioral phenotypes.

  10. Human Life History Strategies

    Directory of Open Access Journals (Sweden)

    Kristine J. Chua

    2016-12-01

    Full Text Available Human life history (LH strategies are theoretically regulated by developmental exposure to environmental cues that ancestrally predicted LH-relevant world states (e.g., risk of morbidity–mortality. Recent modeling work has raised the question of whether the association of childhood family factors with adult LH variation arises via (i direct sampling of external environmental cues during development and/or (ii calibration of LH strategies to internal somatic condition (i.e., health, which itself reflects exposure to variably favorable environments. The present research tested between these possibilities through three online surveys involving a total of over 26,000 participants. Participants completed questionnaires assessing components of self-reported environmental harshness (i.e., socioeconomic status, family neglect, and neighborhood crime, health status, and various LH-related psychological and behavioral phenotypes (e.g., mating strategies, paranoia, and anxiety, modeled as a unidimensional latent variable. Structural equation models suggested that exposure to harsh ecologies had direct effects on latent LH strategy as well as indirect effects on latent LH strategy mediated via health status. These findings suggest that human LH strategies may be calibrated to both external and internal cues and that such calibrational effects manifest in a wide range of psychological and behavioral phenotypes.

  11. Experience and Life History. Roskilde University Life History Project Paper.

    Science.gov (United States)

    Salling Olesen, Henning

    The Life History Project at Denmark's Roskilde University is a 5-year research project that was initiated in 1998 to examine learning and participation in adult and continuing education from a life history perspective. The project was designed to build on a broad range of qualitative interview studies and case studies into learning processes. The…

  12. Seeing How Far I've Come: The Impact of the Digital Sexual Life History Calendar on Young Adult Research Participants.

    Science.gov (United States)

    Bay-Cheng, Laina Y

    2017-01-01

    The Digital Sexual Life History Calendar (d/SLHC) is a Web-based platform for collecting young adults' sexual histories. In addition to collecting diverse data, the d/SLHC was designed to benefit participants by enabling reflection on their sexual and relationship experiences in the context of other life events and circumstances. In a pilot study of the d/SLHC, survey data were collected to test whether creating a d/SLHC timeline had any impact on sexual well-being. A sample of 18- to 25-year-old participants recruited through Amazon Mechanical Turk (MTurk) completed an online survey about sexuality and relationships. Of those, 113 also completed d/SLHC timelines and 262 served as a comparison group. Six months later, participants from both groups were invited to complete a follow-up survey (total N = 249). Repeated-measures analysis of variance (ANOVA) results indicated that participants who completed d/SLHC timelines exhibited higher sexual esteem immediately following d/SLHC completion and at follow-up. No changes in sexual esteem were observed in the comparison group, and there were no differences between the groups with regard to sexual health behaviors and outcomes. These findings suggest that sexuality studies may have the potential to yield not only rich data for researchers but also rich experiences for participants.

  13. Media life of the young

    DEFF Research Database (Denmark)

    Westlund, Oscar; Bjur, Jakob

    2014-01-01

    This is a thorough investigation into contemporary young people and their media life. The article conceptualizes a typology of media life, drawing on a theoretical body involving the sociology of generations, life course research, media life and individualization. This empirically derived typology...... makes a strong instrument for an understanding of the media life of the young, furnishing insights into how they have constructed their use of media. The investigation is based on a robust national survey with Swedes born 1994–2001, conducted in 2010, and focusing on four media: television, gaming......, the Internet and mobile devices. Two of the findings are particularly surprising. Firstly, the results reveal that the young generally lead heterogeneous media lives, varying with age and sex. Secondly, although some young people literarily live their life in media, there are also de facto young who live...

  14. Life History Patterns

    DEFF Research Database (Denmark)

    Jones, Owen

    2016-01-01

    of these patterns and highlights the need to consider senescence from a broad taxonomic scope to truly understand the evolution of aging. Keywords: Aging; Demography; Evolution; Fertility; Gompertz; Life span; Mortality; Ontogenescence; Reproduction; Reproductive senescence; Senescence; Survivorship...

  15. Interrupting Life History: The Evolution of Relationship within Research

    Science.gov (United States)

    Hallett, Ronald E.

    2013-01-01

    In this paper the author explores how relationships are defined within the context of constructing a life history. The life history of Benjamin, a homeless young man transitioning to adulthood, is used to illustrate how difficult it is to define the parameters of the research environment. During an "ethically important moment" in the…

  16. Dynamic heterogeneity in life histories

    DEFF Research Database (Denmark)

    Tuljapurkar, Shripad; Steiner, Uli; Orzack, Steven Hecht

    2009-01-01

    or no fixed heterogeneity influences this trait. We propose that dynamic heterogeneity provides a 'neutral' model for assessing the possible role of unobserved 'quality' differences between individuals. We discuss fitness for dynamic life histories, and the implications of dynamic heterogeneity...... generate dynamic heterogeneity: life-history differences produced by stochastic stratum dynamics. We characterize dynamic heterogeneity in a range of species across taxa by properties of the Markov chain: the entropy, which describes the extent of heterogeneity, and the subdominant eigenvalue, which...... distributions of lifetime reproductive success. Dynamic heterogeneity contrasts with fixed heterogeneity: unobserved differences that generate variation between life histories. We show by an example that observed distributions of lifetime reproductive success are often consistent with the claim that little...

  17. Life History Trade-offs

    NARCIS (Netherlands)

    Smallegange, I.M.; Kliman, R.M.

    2016-01-01

    Trade-offs play a central role in life history theory. This article explains why they exist, how they arise, how they can be measured, and briefly discusses their evolution. Three important trade-offs are discussed in detail: the trade-off between current reproduction and survival, between current

  18. Family History in Young Patients With Stroke.

    Science.gov (United States)

    Thijs, Vincent; Grittner, Ulrike; Dichgans, Martin; Enzinger, Christian; Fazekas, Franz; Giese, Anne-Katrin; Kessler, Christof; Kolodny, Edwin; Kropp, Peter; Martus, Peter; Norrving, Bo; Ringelstein, Erich Bernd; Rothwell, Peter M; Schmidt, Reinhold; Tanislav, Christian; Tatlisumak, Turgut; von Sarnowski, Bettina; Rolfs, Arndt

    2015-07-01

    Family history of stroke is an established risk factor for stroke. We evaluated whether family history of stroke predisposed to certain stroke subtypes and whether it differed by sex in young patients with stroke. We used data from the Stroke in Fabry Patients study, a large prospective, hospital-based, screening study for Fabry disease in young patients (aged stroke in whom cardiovascular risk factors and family history of stroke were obtained and detailed stroke subtyping was performed. A family history of stroke was present in 1578 of 4232 transient ischemic attack and ischemic stroke patients (37.3%). Female patients more often had a history of stroke in the maternal lineage (P=0.027) than in the paternal lineage. There was no association with stroke subtype according to Trial of Org 10172 in Acute Stroke Treatment nor with the presence of white matter disease on brain imaging. Patients with dissection less frequently reported a family history of stroke (30.4% versus 36.3%; P=0.018). Patients with a parental history of stroke more commonly had siblings with stroke (3.6% versus 2.6%; P=0.047). Although present in about a third of patients, a family history of stroke is not specifically related to stroke pathogenic subtypes in patients with young stroke. Young women with stroke more often report stroke in the maternal lineage. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00414583. © 2015 American Heart Association, Inc.

  19. Understanding young stars - A history

    International Nuclear Information System (INIS)

    Stahler, S.W.

    1988-01-01

    The history of pre-main-sequence theory is briefly reviewed. The paper of Henyey et al. (1955) is seen as an important transitional work, one which abandoned previous simplifying assumptions yet failed to incorporate newer insights into the surface structure of late-type stars. The subsequent work of Hayashi and his contemporaries is outlined, with an emphasis on the underlying physical principles. Finally, the recent impact of protostar theory is discussed, and speculations are offered on future developments. 56 references

  20. The Early History of Life

    Science.gov (United States)

    Nisbet, E. G.; Fowler, C. M. R.

    2003-12-01

    The youth of the Earth is strange to us. Many of the most fundamental constraints on life may have been different, especially the oxidation state of the surface. Should we suddenly land on its Hadean or early Archean surface by some sci-fi accident, we would not recognize our home. Above, the sky may have been green or some other unworldly color, and above that the weak young Sun might have been unrecognizable to someone trying to identify it from its spectrum. Below, seismology would show a hot, comparatively low-viscosity interior, possibly with a magma ocean in the deeper part of the upper mantle (Drake and Righter, 2002; Nisbet and Walker, 1982), and a core that, though present, was perhaps rather smaller than today. The continents may have been small islands in an icy sea, mostly frozen with some leads of open water, ( Sleep et al., 2001). Into these icy oceans, huge protruding Hawaii-like volcanoes would have poured out vast far-spreading floods of komatiite lavas in immense eruptions that may have created sudden local hypercane storms to disrupt the nearby icebergs. And meteorites would rain down.Or perhaps it was not so strange, nor so violent. The child is father to the man; young Earth was mother to Old Earth. Earth had hydrogen, silicate rock below and on the surface abundant carbon, which her ancient self retains today. Moreover, Earth was oxygen-rich, as today. Today, a tiny part of the oxygen is free, as air; then the oxygen would have been in the mantle while the surface oxygen was used to handcuff the hydrogen as dihydrogen monoxide. Oxygen dihydride is dense, unlikely to fly off to space, and at the poles, rock-forming. Of all the geochemical features that make Earth unique, the initial degassing (Genesis 2 : b) and then the sustained presence of liquid water is the defining oddity of this planet. Early Earth probably also kept much of its carbon, nitrogen, and sulfur as oxide or hydride. And, after the most cataclysmic events had passed, ˜4.5 Ga

  1. The correlates of HIV testing and impacts on sexual behavior: evidence from a life history study of young people in Kisumu, Kenya

    Directory of Open Access Journals (Sweden)

    Izugbara Chimaraoke O

    2010-07-01

    Full Text Available Abstract Background HIV counseling and testing is considered an important component of HIV prevention and treatment. This paper examines the characteristics of young males and females at the time of first reported HIV test, including the influence of recent sexual partnerships, and investigates how HIV testing and the cumulative number of tests are associated with sexual behaviors within six months of testing. Methods The study uses data from a random sample of youth aged 18-24 years living in Kisumu, Kenya, who were interviewed using a 10-year retrospective life history calendar. Cox regression models were used to examine the correlates of the timing of first HIV test. Variance-correction models for unordered repeated events were employed to examine whether having an HIV test in the previous six months and the cumulative number of tests predict unsafe sexual practices in a given month. Results Sixty-four percent of females and 55% of males reported at least one HIV test in the last 10 years and 40% of females were pregnant the month of first test. Significant correlates of first HIV test included marital aspirations among non-pregnant females, unprotected sex in the previous six months among pregnant females, and concurrency in the previous six months among males. Having a recent HIV test was associated with a decreased likelihood of unprotected sex among ever-pregnant females, an increased likelihood of unprotected sex and "risky" sexual partnerships among never-pregnant females, and an increased likelihood of concurrency among males. Repeated HIV testing was associated with a lower likelihood of concurrency among males and involvement in "risky" sexual partnerships among males and never-pregnant females. Conclusions The high rate of pregnancy at first test suggests that promotion of HIV testing as part of prevention of mother-to-child transmission is gaining success. Further research is warranted to examine how and why behavior change is

  2. The correlates of HIV testing and impacts on sexual behavior: evidence from a life history study of young people in Kisumu, Kenya.

    Science.gov (United States)

    Kabiru, Caroline W; Luke, Nancy; Izugbara, Chimaraoke O; Zulu, Eliya M

    2010-07-13

    HIV counseling and testing is considered an important component of HIV prevention and treatment. This paper examines the characteristics of young males and females at the time of first reported HIV test, including the influence of recent sexual partnerships, and investigates how HIV testing and the cumulative number of tests are associated with sexual behaviors within six months of testing. The study uses data from a random sample of youth aged 18-24 years living in Kisumu, Kenya, who were interviewed using a 10-year retrospective life history calendar. Cox regression models were used to examine the correlates of the timing of first HIV test. Variance-correction models for unordered repeated events were employed to examine whether having an HIV test in the previous six months and the cumulative number of tests predict unsafe sexual practices in a given month. Sixty-four percent of females and 55% of males reported at least one HIV test in the last 10 years and 40% of females were pregnant the month of first test. Significant correlates of first HIV test included marital aspirations among non-pregnant females, unprotected sex in the previous six months among pregnant females, and concurrency in the previous six months among males. Having a recent HIV test was associated with a decreased likelihood of unprotected sex among ever-pregnant females, an increased likelihood of unprotected sex and "risky" sexual partnerships among never-pregnant females, and an increased likelihood of concurrency among males. Repeated HIV testing was associated with a lower likelihood of concurrency among males and involvement in "risky" sexual partnerships among males and never-pregnant females. The high rate of pregnancy at first test suggests that promotion of HIV testing as part of prevention of mother-to-child transmission is gaining success. Further research is warranted to examine how and why behavior change is influenced by client- versus provider-initiated testing. The influence

  3. Life histories in occupational therapy clinical practice.

    Science.gov (United States)

    Frank, G

    1996-04-01

    This article defines and compares several narrative methods used to describe and interpret patients' lives. The biographical methods presented are case histories, life-charts, life histories, life stories, assisted autobiography, hermeneutic case reconstruction, therapeutic employment, volitional narratives, and occupational storytelling and story making. Emphasis is placed the clinician as a collaborator and interpreter of the patient's life through ongoing interactions and dialogue.

  4. Life history types and strategies

    DEFF Research Database (Denmark)

    Boel, Mikkel

    strategies and types in migratory freshwater fish, using brown trout and alewife as study organisms. Firstly, we investigated underlying mechanisms of resident and migratory life history strategies of salmonids, using indicators for nutritional status, stress, tissue damage and smoltification. Secondly...... III the minimum predation from cormorants and herons was estimated over a three year period on the brown trout population of of Lake Hald. The magnitude of the predation pressure from both bird species were very similar and when summed up, the avian predation accounted for an average minimum of 37.......2 % of the annual brown trout mortality in the lake and 10.1 % in the tributaries. This result illustrates that avian predation in the lake can be quite substantial and potentially plays an important role in the population dynamics of brown trout. Cormorants alone were responsible 21.2% in the lake and the arrival...

  5. Contrasting population and life history responses of a young morph-pair of European whitefish to the invasion of a specialised coregonid competitor, vendace.

    Directory of Open Access Journals (Sweden)

    Odd Terje Sandlund

    Full Text Available Invasions of non-native species represent a global problem of great scientific interest. Here we study in detail the response in population and life history characteristics of closely related native species, with divergent habitat preferences, that are impacted by an invading species over a sufficient time period to allow a new stable state to become established. A time series of 20 years starting at the first occurrence of the invader (vendace Coregonus albula (L. allows exploration of the long term population and life history response of two ecologically, morphologically, and genetically different native sympatric morphs (DR- and SR- of congeneric whitefish C. lavaretus (L.. The whitefish morphs are taxonomically equally related to the invading vendace, but only the planktivorous DR-whitefish share its pelagic niche. We would expect that the ecological differences between the whitefish morphs may be used as a predictor of competitive effects. Vendace exhibited an initial boom-and-bust development, and has continued to fluctuate in density. The responses of the pelagic DR-whitefish were: i an immediate habitat shift, ii a subsequent population decline caused by increased annual mortality, and iii a new stable state at a lower density and apparently relaxed competition. The ecologically more distant benthivorous SR-whitefish also showed significant, but a much more limited response during this process, indicating damped indirect interactions through the food-web. This long-term case-study found that in two native eco-species equally related to the invader, only one of the eco-species was highly affected. Direct competition for resources is obviously important for species interactions, whereas the taxonomic relatedness per se seems to offer little predictive power for invasion effects.

  6. Globalization and Life History Research: Fragments of a Life Foretold

    Science.gov (United States)

    Tierney, William G.

    2010-01-01

    The goal of this paper is to understand, by way of a life history of one low-income working-class youth, how globalization impacts the working class in a developing nation. The concept of globalization and the method of life history seem diametrically opposed. Globalization is an idea about large social forces that impact the economic and material…

  7. Evolutionary biology and life histories

    Directory of Open Access Journals (Sweden)

    Brown, C. R.

    2004-06-01

    Full Text Available The demographic processes that drive the spread of populations through environments and in turn determine the abundance of organisms are the same demographic processes that drive the spread of genes through populations and in turn determine gene frequencies and fitness. Conceptually, marked similarities exist in the dynamic processes underlying population ecology and those underlying evolutionary biology. Central to an understanding of both disciplines is life history and its component demographic rates, such as survival, fecundity, and age of first breeding, and biologists from both fields have a vested interest in good analytical machinery for the estimation and analysis of these demographic rates. In the EURING conferences, we have been striving since the mid 1980s to promote a quantitative understanding of demographic rates through interdisciplinary collaboration between ecologists and statisticians. From the ecological side, the principal impetus has come from population biology, and in particular from wildlife biology, but the importance of good quantitative insights into demographic processes has long been recognized by a number of evolutionary biologists (e.g., Nichols & Kendall, 1995; Clobert, 1995; Cooch et al., 2002. In organizing this session, we have aimed to create a forum for those committed to gaining the best possible understanding of evolutionary processes through the application of modern quantitative methods for the collection and interpretation of data on marked animal populations. Here we present a short overview of the material presented in the session on evolutionary biology and life histories. In a plenary talk, Brown & Brown (2004 explored how mark–recapture methods have allowed a better understanding of the evolution of group–living and alternative reproductive tactics in colonial cliff swallows (Petrochelidon pyrrhonota. By estimating the number of transient birds passing through colonies of different sizes, they

  8. Population momentum across vertebrate life histories

    Science.gov (United States)

    Koons, D.N.; Grand, J.B.; Arnold, J.M.

    2006-01-01

    Population abundance is critically important in conservation, management, and demographic theory. Thus, to better understand how perturbations to the life history affect long-term population size, we examined population momentum for four vertebrate classes with different life history strategies. In a series of demographic experiments we show that population momentum generally has a larger effect on long-term population size for organisms with long generation times than for organisms with short generation times. However, patterns between population momentum and generation time varied across taxonomic groups and according to the life history parameter that was changed. Our findings indicate that momentum may be an especially important aspect of population dynamics for long-lived vertebrates, and deserves greater attention in life history studies. Further, we discuss the importance of population momentum in natural resource management, pest control, and conservation arenas. ?? 2006 Elsevier B.V. All rights reserved.

  9. Bluefin Tuna Life History (1972-1979)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Catch and size data for animals from which a collection of fish parts were done for life history studies. These samples will be used in comparison studies with more...

  10. The History and Accomplishments of the LIVESTRONG Young Adult Alliance.

    Science.gov (United States)

    Mathews-Bradshaw, Beth; Johnson, Rebecca; Kaplan, Stuart; Craddock, Kelli; Hayes-Lattin, Brandon

    2011-03-01

    This article outlines the history, background, and accomplishments of the LIVESTRONG Young Adult Alliance. The LIVESTRONG Young Adult Alliance, a program of the Lance Armstrong Foundation, was developed as a vehicle for a strategic plan designed to implement the Adolescent and Young Adult Oncology Progress Review Group (AYAO PRG) recommendations. The AYAO PRG was co-sponsored by Lance Armstrong Foundation and the National Cancer Institute (NCI); both LIVESTRONG and NCI provide strategic oversight and guidance to the Alliance. Highlights and accomplishments: The Alliance accomplishments include the publication of disease-specific retrospective analyses, funding of an AYA cohort study and biorepository proposal, publication of two position statements on guidelines for care of AYAs with cancer and training for AYA oncology health professionals, promotion of an international charter of rights for AYA cancer patients, creation and distribution of a survey to college health professionals, creation and implementation of a Cancer Centers Working Group and Institutional Review Board Toolkit, and continued growth and collaboration through an annual meeting. The growth and success of the Alliance has coincided with the growth of AYA oncology as a field. The collaborative environment of the Alliance draws together a diverse group of individuals united in the effort to increase survival rates and improve the quality of life for adolescents and young adults diagnosed with cancer.

  11. Multistate analysis of life histories with R

    CERN Document Server

    Willekens, Frans

    2014-01-01

    This book provides an introduction to multistate event history analysis. It is an extension of survival analysis, in which a single terminal event (endpoint) is considered and the time-to-event is studied. Multistate models focus on life histories or trajectories, conceptualized as sequences of states and sequences of transitions between states. Life histories are modeled as realizations of continuous-time Markov processes. The model parameters, transition rates, are estimated from data on event counts and populations at risk, using the statistical theory of counting processes. The Comprehensive R Network Archive (CRAN) includes several packages for multistate modeling. This book is about Biograph. The package is designed to (a) enhance exploratory analysis of life histories and (b) make multistate modeling accessible. The package incorporates utilities that connect to several packages for multistate modeling, including survival, eha, Epi, mvna, etm, mstate, msm, and TraMineR for sequence analysis. The book ...

  12. Early life trauma exposure and stress sensitivity in young children.

    Science.gov (United States)

    Grasso, Damion J; Ford, Julian D; Briggs-Gowan, Margaret J

    2013-01-01

    The current study replicates and extends work with adults that highlights the relationship between trauma exposure and distress in response to subsequent, nontraumatic life stressors. The sample included 213 2-4-year-old children in which 64.3% had a history of potential trauma exposure. Children were categorized into 4 groups based on trauma history and current life stress. In a multivariate analysis of variance, trauma-exposed children with current life stressors had elevated internalizing and externalizing problems compared with trauma-exposed children without current stress and nontrauma-exposed children with and without current stressors. The trauma-exposed groups with or without current stressors did not differ on posttraumatic stress disorder symptom severity. Accounting for number of traumatic events did not change these results. These findings suggest that early life trauma exposure may sensitize young children and place them at risk for internalizing or externalizing problems when exposed to subsequent, nontraumatic life stressors.

  13. Lemur Biorhythms and Life History Evolution.

    Directory of Open Access Journals (Sweden)

    Russell T Hogg

    Full Text Available Skeletal histology supports the hypothesis that primate life histories are regulated by a neuroendocrine rhythm, the Havers-Halberg Oscillation (HHO. Interestingly, subfossil lemurs are outliers in HHO scaling relationships that have been discovered for haplorhine primates and other mammals. We present new data to determine whether these species represent the general lemur or strepsirrhine condition and to inform models about neuroendocrine-mediated life history evolution. We gathered the largest sample to date of HHO data from histological sections of primate teeth (including the subfossil lemurs to assess the relationship of these chronobiological measures with life history-related variables including body mass, brain size, age at first female reproduction, and activity level. For anthropoids, these variables show strong correlations with HHO conforming to predictions, though body mass and endocranial volume are strongly correlated with HHO periodicity in this group. However, lemurs (possibly excepting Daubentonia do not follow this pattern and show markedly less variability in HHO periodicity and lower correlation coefficients and slopes. Moreover, body mass is uncorrelated, and brain size and activity levels are more strongly correlated with HHO periodicity in these animals. We argue that lemurs evolved this pattern due to selection for risk-averse life histories driven by the unpredictability of the environment in Madagascar. These results reinforce the idea that HHO influences life history evolution differently in response to specific ecological selection regimes.

  14. Lemur Biorhythms and Life History Evolution.

    Science.gov (United States)

    Hogg, Russell T; Godfrey, Laurie R; Schwartz, Gary T; Dirks, Wendy; Bromage, Timothy G

    2015-01-01

    Skeletal histology supports the hypothesis that primate life histories are regulated by a neuroendocrine rhythm, the Havers-Halberg Oscillation (HHO). Interestingly, subfossil lemurs are outliers in HHO scaling relationships that have been discovered for haplorhine primates and other mammals. We present new data to determine whether these species represent the general lemur or strepsirrhine condition and to inform models about neuroendocrine-mediated life history evolution. We gathered the largest sample to date of HHO data from histological sections of primate teeth (including the subfossil lemurs) to assess the relationship of these chronobiological measures with life history-related variables including body mass, brain size, age at first female reproduction, and activity level. For anthropoids, these variables show strong correlations with HHO conforming to predictions, though body mass and endocranial volume are strongly correlated with HHO periodicity in this group. However, lemurs (possibly excepting Daubentonia) do not follow this pattern and show markedly less variability in HHO periodicity and lower correlation coefficients and slopes. Moreover, body mass is uncorrelated, and brain size and activity levels are more strongly correlated with HHO periodicity in these animals. We argue that lemurs evolved this pattern due to selection for risk-averse life histories driven by the unpredictability of the environment in Madagascar. These results reinforce the idea that HHO influences life history evolution differently in response to specific ecological selection regimes.

  15. Quality of life, self-esteem and worries in young adult survivors of childhood cancer

    NARCIS (Netherlands)

    Langeveld, N. E.; Grootenhuis, M. A.; Voûte, P. A.; de Haan, R. J.; van den Bos, C.

    2004-01-01

    This study assessed quality of life, self-esteem and worries in young adult survivors of childhood cancer compared to a group of young adults with no history of cancer. The impact of demographic, medical and treatment factors and self-esteem on survivors' quality of life and worries was studied.

  16. Parasitism shaping host life-history evolution

    DEFF Research Database (Denmark)

    Fredensborg, Brian Lund; Poulin, R

    2006-01-01

    1. Variation in life-history strategies among conspecific populations indicates the action of local selective pressures; recently, parasitism has been suggested as one of these local forces. 2. Effects of trematode infections on reproductive effort, juvenile growth, size at maturity and susceptib......1. Variation in life-history strategies among conspecific populations indicates the action of local selective pressures; recently, parasitism has been suggested as one of these local forces. 2. Effects of trematode infections on reproductive effort, juvenile growth, size at maturity...

  17. Life History Strategy and Disordered Eating Behavior

    Directory of Open Access Journals (Sweden)

    Catherine Salmon

    2009-10-01

    Full Text Available A sample of female undergraduates completed a packet of questionnaires consisting of the Arizona Life History Battery, a modified version of the Eating Disorders Inventory, the Behavioral Regulation scales from the Behavior Rating Inventory of Executive Function, and two measures of Female Intrasexual Competitiveness that distinguished between competition for mates and competition for status. As predicted, Executive Functions completely mediated the relation between Slow Life History Strategy and Disordered Eating Behavior. Surprisingly, however, the relation between Female Intrasexual Competitiveness (competition for mates and competition for status and Disordered Eating Behavior was completely spurious, with executive functions serving as a common cause underlying the inhibition of both Disordered Eating Behavior and Female Intrasexual Competitiveness. The protective function of Slow Life History Strategy with respect to Disordered Eating Behavior apparently resides in a higher degree of Behavioral Regulation, a type of Executive Function. The enhanced Behavioral Regulation or self-control, of individuals with a Slow Life History Strategy is also protective against hazardously escalated levels of Female Intrasexual Competitiveness.

  18. The life trajectories modality of oral history

    Directory of Open Access Journals (Sweden)

    Rita de Cássia Gonçalves

    2007-05-01

    Full Text Available This article seeks to explore the potential of qualitative research. It presents the life trajectory modality of the oral history method, to discuss the possibility of its utilization in scientific research in the Social Work profession. The epistemological foundations of oral history are discussed to establish its scientific character. The life trajectories modality is presented as a historic and social construction that utilizes different interview techniques to give voice to previously invisible subjects, indicating the principal phases of the methodological procedures used in this approach. The conclusions highlight the importance of the construction of this model and its projection as a research proposal that implies a process of understanding and analyzing the social universes that are contextualized and interconnected, considering the realities of the life trajectories of the subjects studied.

  19. "Life history space": a multivariate analysis of life history variation in extant and extinct Malagasy lemurs.

    Science.gov (United States)

    Catlett, Kierstin K; Schwartz, Gary T; Godfrey, Laurie R; Jungers, William L

    2010-07-01

    Studies of primate life history variation are constrained by the fact that all large-bodied extant primates are haplorhines. However, large-bodied strepsirrhines recently existed. If we can extract life history information from their skeletons, these species can contribute to our understanding of primate life history variation. This is particularly important in light of new critiques of the classic "fast-slow continuum" as a descriptor of variation in life history profiles across mammals in general. We use established dental histological methods to estimate gestation length and age at weaning for five extinct lemur species. On the basis of these estimates, we reconstruct minimum interbirth intervals and maximum reproductive rates. We utilize principal components analysis to create a multivariate "life history space" that captures the relationships among reproductive parameters and brain and body size in extinct and extant lemurs. Our data show that, whereas large-bodied extinct lemurs can be described as "slow" in some fashion, they also varied greatly in their life history profiles. Those with relatively large brains also weaned their offspring late and had long interbirth intervals. These were not the largest of extinct lemurs. Thus, we distinguish size-related life history variation from variation that linked more strongly to ecological factors. Because all lemur species larger than 10 kg, regardless of life history profile, succumbed to extinction after humans arrived in Madagascar, we argue that large body size increased the probability of extinction independently of reproductive rate. We also provide some evidence that, among lemurs, brain size predicts reproductive rate better than body size. (c) 2010 Wiley-Liss, Inc.

  20. Evolutionary assembly rules for fish life histories

    DEFF Research Database (Denmark)

    Charnov, E.L.; Gislason, Henrik; Pope, J.G.

    2012-01-01

    length along the growth trajectory within the species. We then interpret K in terms of the VBGE in mass , and show that the previous equation is itself equivalent to a -1/3 power function rule between M and the mass at first reproduction (W α); this new -1/3 power function emerges directly from the life...... history that maximizes Darwinian fitness in non-growing populations. We merge this M, W α power function with other power functions to produce general across-species scaling rules for yearly reproductive allocation, reproductive effort and age at first reproduction in fish. We then suggest a new way...... to classify habitats (or lifestyles) as to the life histories they should contain, and we contrast our scheme with the widely used Winemiller-Rose fish lifestyle classification...

  1. "Our Journey through Time": An Oral History Project Carried out by Young People with Learning Disabilities

    Science.gov (United States)

    Bentley, Sarah; Nicholls, Rickie; Price, Maxine; Wilkinson, Aaron; Purcell, Matthew; Woodhall, Martin; Walmsley, Jan

    2011-01-01

    We are five young people with learning disabilities who found out about the history of hospitals for people with learning disabilities in our area, and made a film about the project. The project taught us what life had been like for some people with learning disabilities only 30 years ago. It was very different to our lives; we have more choice,…

  2. Oxidative stress and life histories: unresolved issues and current needs

    OpenAIRE

    Speakman, John R.; Blount, Jonathan D.; Bronikowski, Anne M.; Buffenstein, Rochelle; Isaksson, Caroline; Kirkwood, Tom B. L.; Monaghan, Pat; Ozanne, Susan E.; Beaulieu, Micha?l; Briga, Michael; Carr, Sarah K.; Christensen, Louise L.; Cochem?, Helena M.; Cram, Dominic L.; Dantzer, Ben

    2015-01-01

    Abstract Life?history theory concerns the trade?offs that mold the patterns of investment by animals between reproduction, growth, and survival. It is widely recognized that physiology plays a role in the mediation of life?history trade?offs, but the details remain obscure. As life?history theory concerns aspects of investment in the soma that influence survival, understanding the physiological basis of life histories is related, but not identical, to understanding the process of aging. One i...

  3. Oxidative stress and life histories : Unresolved issues and current needs

    NARCIS (Netherlands)

    Speakman, John R.; Blount, Jonathan D.; Bronikowski, Anne M.; Buffenstein, Rochelle; Isaksson, Caroline; Kirkwood, Tom B. L.; Monaghan, Pat; Ozanne, Susan E.; Beaulieu, Michael; Briga, Michael; Carr, Sarah K.; Christensen, Louise L.; Cocheme, Helena M.; Cram, Dominic L.; Dantzer, Ben; Harper, Jim M.; Jurk, Diana; King, Annette; Noguera, Jose C.; Salin, Karine; Sild, Elin; Simons, Mirre J. P.; Smith, Shona; Stier, Antoine; Tobler, Michael; Vitikainen, Emma; Peaker, Malcolm; Selman, Colin

    2015-01-01

    Life-history theory concerns the trade-offs that mold the patterns of investment by animals between reproduction, growth, and survival. It is widely recognized that physiology plays a role in the mediation of life-history trade-offs, but the details remain obscure. As life-history theory concerns

  4. Immune defense and host life history.

    Science.gov (United States)

    Zuk, Marlene; Stoehr, Andrew M

    2002-10-01

    Recent interest has focused on immune response in an evolutionary context, with particular attention to disease resistance as a life-history trait, subject to trade-offs against other traits such as reproductive effort. Immune defense has several characteristics that complicate this approach, however; for example, because of the risk of autoimmunity, optimal immune defense is not necessarily maximum immune defense. Two important types of cost associated with immunity in the context of life history are resource costs, those related to the allocation of essential but limited resources, such as energy or nutrients, and option costs, those paid not in the currency of resources but in functional or structural components of the organism. Resource and option costs are likely to apply to different aspects of resistance. Recent investigations into possible trade-offs between reproductive effort, particularly sexual displays, and immunity have suggested interesting functional links between the two. Although all organisms balance the costs of immune defense against the requirements of reproduction, this balance works out differently for males than it does for females, creating sex differences in immune response that in turn are related to ecological factors such as the mating system. We conclude that immune response is indeed costly and that future work would do well to include invertebrates, which have sometimes been neglected in studies of the ecology of immune defense.

  5. Predicting life-history adaptations to pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Maltby, L. [Univ. of Sheffield (United Kingdom). Dept. of Animal and Plant Sciences

    1995-12-31

    Animals may adapt to pollutant stress so that individuals from polluted environments are less susceptible than those from unpolluted environments. In addition to such direct adaptations, animals may respond to pollutant stress by life-history modifications; so-called indirect adaptations. This paper will demonstrate how, by combining life-history theory and toxicological data, it is possible to predict stress-induced alterations in reproductive output and offspring size. Pollutant-induced alterations in age-specific survival in favor of adults and reductions in juvenile growth, conditions are predicted to select for reduced investment in reproduction and the allocation of this investment into fewer, larger offspring. Field observations on the freshwater crustaceans, Asellus aquaticus and Gammarus pulex, support these predictions. Females from metal-polluted sites had lower investment in reproduction and produced larger offspring than females of the same species from unpolluted sites. Moreover, interpopulation differences in reproductive biology persisted in laboratory cultures indicating that they had a genetic basis and were therefore due to adaptation rather than acclimation. The general applicability of this approach will be considered.

  6. Life history consequences of mammal sibling rivalry.

    Science.gov (United States)

    Stockley, P; Parker, G A

    2002-10-01

    Mammal life history traits relating to growth and reproduction are extremely diverse. Sibling rivalry may contribute to selection pressures influencing this diversity, because individuals that are relatively large at birth typically have an advantage in competition for milk. However, selection for increased growth rate is likely to be constrained by kin selection and physiological costs. Here, we present and test a model examining the ESS (evolutionarily stable strategy) balance between these constraints and advantages associated with increased prenatal growth in mammal sibling rivalry. Predictions of the model are supported by results of comparative analyses for the Carnivora and Insectivora, which demonstrate an increase in prenatal growth rate with increasing intensity of postnatal scramble competition, and a decrease in postnatal growth rate relative to size at birth. Because increased prenatal growth rates are predicted to select for reduced gestation length under certain conditions, our study also indicates that sibling rivalry may contribute to selection pressures influencing variation in altriciality and precociality among mammals.

  7. Procrastination as a Fast Life History Strategy

    Directory of Open Access Journals (Sweden)

    Bin-Bin Chen

    2016-02-01

    Full Text Available Research has revealed that procrastination—the purposive delay of an intended course of action—is a maladaptive behavior. However, by drawing on an evolutionary life history (LF approach, the present study proposes that procrastination may be an adaptive fast LF strategy characterized by prioritizing immediate benefits with little regard to long-term consequences. A total of 199 undergraduate students completed measures of procrastination and future orientation and the Mini-K scale, which measures the slow LF strategy. Structural equation modeling revealed that, as predicted, procrastination was negatively associated with a slow LF strategy both directly and indirectly through the mediation of future orientation. These results define the fast LF origin of procrastination.

  8. Dynamic heterogeneity and life history variability in the kittiwake

    DEFF Research Database (Denmark)

    Steiner, Uli; Tuljapurkar, Shripad; Orzack, Steven Hecht

    2010-01-01

    1. Understanding the evolution of life histories requires an assessment of the process that generates variation in life histories. Within-population heterogeneity of life histories can be dynamically generated by stochastic variation of reproduction and survival or be generated by individual...... differences that are fixed at birth. 2. We show for the kittiwake that dynamic heterogeneity is a sufficient explanation of observed variation of life histories. 3. The total heterogeneity in life histories has a small contribution from reproductive stage dynamics and a large contribution from survival...... differences. We quantify the diversity in life histories by metrics computed from the generating stochastic process. 4. We show how dynamic heterogeneity can be used as a null model and also how it can lead to positive associations between reproduction and survival across the life span. 5. We believe our...

  9. How Life History Can Sway the Fixation Probability of Mutants

    Science.gov (United States)

    Li, Xiang-Yi; Kurokawa, Shun; Giaimo, Stefano; Traulsen, Arne

    2016-01-01

    In this work, we study the effects of demographic structure on evolutionary dynamics when selection acts on reproduction, survival, or both. In contrast to the previously discovered pattern that the fixation probability of a neutral mutant decreases while the population becomes younger, we show that a mutant with a constant selective advantage may have a maximum or a minimum of the fixation probability in populations with an intermediate fraction of young individuals. This highlights the importance of life history and demographic structure in studying evolutionary dynamics. We also illustrate the fundamental differences between selection on reproduction and selection on survival when age structure is present. In addition, we evaluate the relative importance of size and structure of the population in determining the fixation probability of the mutant. Our work lays the foundation for also studying density- and frequency-dependent effects in populations when demographic structures cannot be neglected. PMID:27129737

  10. Life history evolution in social insects : A female perspective

    NARCIS (Netherlands)

    Negroni, Matteo Antoine; Jongepier, Evelien; Feldmeyer, Barbara; Kramer, Boris H.; Foitzik, Susanne

    2016-01-01

    Social insects are known for their unusual life histories with fecund, long-lived queens and sterile, short-lived workers. We review ultimate factors underlying variation in life history strategies in female social insects, whose social life reshapes common trade-offs, such as the one between

  11. Life satisfaction of young adults with spina bifida

    NARCIS (Netherlands)

    Barf, H. A.; Post, M. W. M.; Verhoef, M.; Jennekens-Schinkel, A.; Gooskens, R. H. J. M.; Prevo, A. J. H.

    This study concerns life satisfaction and its determinants in Dutch young adults with spina bifida (SB). Data on life satisfaction (Life Satisfaction Questionnaire [LiSat-9]) were related to hydrocephalus, lesion level, disabilities, and demographic variables. In total, 179 young adults with SB

  12. Invader population speeds up life history during colonization

    OpenAIRE

    Amundsen, Per-Arne; Salonen, Erno; Niva, Teuvo; Gjelland, Karl Øystein; Præbel, Kim; Sandlund, Odd Terje; Knudsen, Rune; Bøhn, Thomas

    2012-01-01

    We explore the long-term developments in population biology and life history during the invasion and establishment of the fish species vendace Coregonus albula in a subarctic watercourse by comparing life-history traits and molecular genetic estimates between the source and the colonist population. The two populations exhibited highly contrasting life-history strategies. Relative to the source population, the colonist population was characterized by slower somatic growth rates, earlier sexual...

  13. Social Structure and Individual Agency in Second Language Learning: Evidence from Three Life Histories

    Science.gov (United States)

    Flowerdew, John; Miller, Lindsay

    2008-01-01

    This paper examines the issue of social structure and individual agency in language learning through the life histories of three young engineering graduates in Hong Kong. English is identified as an important form of cultural capital, which to a considerable extent determines the development of the three individuals, each of whom comes from a…

  14. Variability in the developmental life history of the genus Gorilla.

    Science.gov (United States)

    Stoinski, Tara S; Perdue, Bonnie; Breuer, Thomas; Hoff, Michael P

    2013-10-01

    Life history is influenced by factors both intrinsic (e.g., body and relative brain size) and extrinsic (e.g., diet, environmental instability) to organisms. In this study, we examine the prediction that energetic risk influences the life history of gorillas. Recent comparisons suggest that the more frugivorous western lowland gorilla shows increased infant dependence, and thus a slower life history, than the primarily folivorous mountain gorilla to buffer against the risk of starvation during periods of food unpredictability. We further tested this hypothesis by incorporating additional life history data from wild western lowland gorillas and captive western lowland gorillas with the assumption that the latter live under ecological conditions of energetic risk that more closely resemble those of mountain gorillas and thus should show faster life histories than wild members of the species. Overall, we found captive western lowland and wild mountain gorillas to have faster developmental life histories than wild western lowland gorillas, weaning their infants approximately a year earlier and thus reducing interbirth intervals by a year. These results provide support that energetic risk plays an important role in determining gorilla life history. Unlike previous assertions, gorillas do not have substantially faster life histories, at least at the genus level, than other great apes. This calls for a re-evaluation of theories concerning comparative ape life history and evolution and highlights the need for data from additional populations that vary in energetic risk. Copyright © 2013 Wiley Periodicals, Inc.

  15. Primates and the Evolution of Long-Slow Life Histories

    Science.gov (United States)

    Jones, James Holland

    2011-01-01

    Summary Primates are characterized by relatively late ages at first reproduction, long lives and low fertility. Together, these traits define a life-history of reduced reproductive effort. Understanding the optimal allocation of reproductive effort, and specifically reduced reproductive effort, has been one of the key problems motivating the development of life history theory. Because of their unusual constellation of life-history traits, primates play an important role in the continued development of life history theory. In this review, I present the evidence for the reduced reproductive effort life histories of primates and discuss the ways that such life-history tactics are understood in contemporary theory. Such tactics are particularly consistent with the predictions of stochastic demographic models, suggesting a key role for environmental variability in the evolution of primate life histories. The tendency for primates to specialize in high-quality, high-variability food items may make them particularly susceptible to environmental variability and explain their low reproductive-effort tactics. I discuss recent applications of life history theory to human evolution and emphasize the continuity between models used to explain peculiarities of human reproduction and senescence with the long, slow life histories of primates more generally. PMID:21959161

  16. Experiencia in qualitative methodology: History of life

    Directory of Open Access Journals (Sweden)

    María del Socorro Borboa Quintero

    2012-05-01

    Full Text Available From the commercial opening of Mexico the companies compete with transnational companies. In the municipality of Culiacan of the state of Sinaloa the small companies have been harmed mainly by his low level of productivity and competitiveness. Reason why to study two people who even with the complexity of the environment they haveinfluenced for the growth and development of its organization which is important for the local and state development. The intention of the present work, even though some results are included, is to show the method and the instruments used in the investigation. In the first place one poses the problem to investigate, the questions, objectives and hypotheses that orient this work, also includes the design of the field work, that contemplates relevance to use the qualitative method of the tradition life history, the collect and the storage of the data, its analysis and interpretation and some conclusions. The study allowed determining the characteristics and qualities that conform their personality of leader, as well as the identification of the management practices that have implemented.

  17. The History and Timing of Depression Onset as Predictors of Young-Adult Self-Esteem

    Science.gov (United States)

    Lloyd, Donald A.; Ueno, Koji

    2010-01-01

    Depression often emerges early in the lifecourse and is consistently shown to be associated with poor self-esteem. The three main objectives of the current study are to (1) evaluate the association between a history major depression and self-esteem in young adulthood; (2) assess the relationship between timing of depression onset and young adult self-esteem; and (3) help rule out the alternative interpretation that the relationship between major depression and self-esteem is due to state dependence bias stemming from recent depressive symptoms and stressful life events. To address these objectives we use data from a two-wave panel study based on a community sample of young adults in Miami-Dade County, Florida (n = 1,197). Results indicated a history of major depression during sensitive periods of social development is associated with negative changes in self-esteem over a two-year period during the transition to young adulthood. Among those with a history of depression, earlier onset was more problematic than later onset for young adult self-esteem, although the difference disappeared once the level of self-esteem two years prior was controlled. The linkages between the history and timing of depression onset with self-esteem were observed net of recent depressive symptoms and stressful life events, and thus robust to an alternative interpretation of state dependence. The findings support the argument that major depression, especially if it develops earlier during child-adolescent development, has negative consequences for one’s self-esteem. PMID:21860585

  18. Variation in adult life history and stress resistance across five ...

    Indian Academy of Sciences (India)

    Unknown

    Life-history evolution in Drosophila has been extensively studied, and .... Overall, if one looks at studies of adult life history and ...... Thus, if the balance of biotic and abiotic selective ... these four species, and indicate that more detailed work on.

  19. Inadvertent Exemplars: Life History Portraits of Two Socially Just Principals

    Science.gov (United States)

    Scanlan, Martin

    2012-01-01

    This study creates life history portraits of two White middle-class native-English-speaking principals demonstrating commitments to social justice in their work in public elementary schools serving disproportionately high populations of students who are marginalized by poverty, race, and linguistic heritage. Through self-reported life histories of…

  20. To Fairly Tell: Social Mobility, Life Histories, and the Anthropologist

    Science.gov (United States)

    Benei, Veronique

    2010-01-01

    This article focuses on social agents' own understandings of socio-economic mobility and social achievement, exploring the possibilities offered by the tool of "family" life history in the context of formerly Untouchable communities in western India, Maharashtra. While arguing in favour of family life histories as both resource and…

  1. Young peoples’ access to working life in three Nordic countries

    DEFF Research Database (Denmark)

    Jørgensen, Christian Helms

    2018-01-01

    While working life in the Nordic countries generally has a high quality, the question examined in this chapter is how accessible working life is for young people. The chapter examines how upper secondary vocational education (VET) is connected to working life and how it supports young peoples......’ transitions to the labour market in Norway, Denmark and Sweden. The examination includes a conceptual discussion of the links between education and working life in comparative research on VET and transition systems. It explores how the VET systems match the educational demand of young people with the skills...... requirements in working life. In addition, it examines young peoples’ transitions to working life in two selected industries, health care and construction. Also, three new, innovative institutions to mediate between VET and working life are investigat-ed....

  2. Age-dependent male mating tactics in a spider mite-A life-history perspective.

    Science.gov (United States)

    Sato, Yukie; Rühr, Peter T; Schmitz, Helmut; Egas, Martijn; Blanke, Alexander

    2016-10-01

    Males often fight with rival males for access to females. However, some males display nonfighting tactics such as sneaking, satellite behavior, or female mimicking. When these mating tactics comprise a conditional strategy, they are often thought to be explained by resource holding potential (RHP), that is, nonfighting tactics are displayed by less competitive males who are more likely to lose a fight. The alternative mating tactics, however, can also be explained by life-history theory, which predicts that young males avoid fighting, regardless of their RHP, if it pays off to wait for future reproduction. Here, we test whether the sneaking tactic displayed by young males of the two-spotted spider mite can be explained by life-history theory. We tested whether young sneaker males survive longer than young fighter males after a bout of mild or strong competition with old fighter males. We also investigated whether old males have a more protective outer skin-a possible proxy for RHP-by measuring cuticle hardness and elasticity using nanoindentation. We found that young sneaker males survived longer than young fighter males after mild male competition. This difference was not found after strong male competition, which suggests that induction of sneaking tactic is affected by male density. Hardness and elasticity of the skin did not vary with male age. Given that earlier work could also not detect morphometric differences between fighter and sneaker males, we conclude that there is no apparent increase in RHP with age in the mite and age-dependent male mating tactics in the mite can be explained only by life-history theory. Because it is likely that fighting incurs a survival cost, age-dependent alternative mating tactics may be explained by life-history theory in many species when reproduction of old males is a significant factor in fitness.

  3. Health, employment and relationships: Correlates of personal wellbeing in young adults with and without a history of childhood language impairment.

    Science.gov (United States)

    Conti-Ramsden, Gina; Durkin, Kevin; Mok, Pearl L H; Toseeb, Umar; Botting, Nicola

    2016-07-01

    We examine the potential associations between self-rated health, employment situation, relationship status and personal wellbeing in young adults with and without a history of language impairment (LI). In total, 172 24-year-olds from the UK participated, with approximately half (N = 84) having a history of LI. Personal wellbeing was measured using ratings from three questions from the Office for National Statistics regarding life satisfaction, happiness and life being worthwhile. There were similarities between individuals with a history of LI and their age-matched peers in self-rated personal wellbeing. However, regression analyses revealed self-rated health was the most consistent predictor of personal wellbeing for individuals with a history of LI in relation to life satisfaction (21% of variance), happiness (11%) and perceptions that things one does in life are worthwhile (32%). None of the regression analyses were significant for their peers. Similarities on ratings of wellbeing by young adults with and without a history of LI can mask heterogeneity and important differences. Young adults with a history of LI are more vulnerable to the effects of health, employment and relationship status on their wellbeing than their peers. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  4. The Digital Life History Project: Intergenerational Collaborative Research

    Science.gov (United States)

    Loe, Meika

    2013-01-01

    This article describes the Digital Life History Project, a 10-week "lab" linked to a course on aging, in which students and community-dwelling elders work together to create a short digital story honoring the elder's life. After two interview sessions, the pair works together to produce a 3- to 5-minute digital life story narrated by the elder.…

  5. Dynamics and life histories of northern ungulates in changing environments

    Science.gov (United States)

    Hendrichsen, D. K.

    2011-12-01

    Regional climate and local weather conditions can profoundly influence life history parameters (growth, survival, fecundity) and population dynamics in northern ungulates (Post and Stenseth 1999, Coulson et al. 2001). The influence is both direct, for example through reduced growth or survival (Aanes et al. 2000, Tyler et al. 2008), and indirect, for example through changes in resource distribution, phenology and quality, changes which subsequently influence consumer dynamics (Post et al. 2008). By comparing and contrasting data from three spatially independent populations of ungulates, I discuss how variation in local weather parameters and vegetation growth influence spatial and temporal dynamics through changes in life history parameters and/or behavioural dynamics. The data originate from long term (11-15 years) monitoring data from three populations of ungulates in one subarctic and two high Arctic sites; semi-domesticated reindeer (Rangifer tarandus tarandus) in northern Norway, Svalbard reindeer (R. t. platyrhynchus) on Spitsbergen and muskoxen (Ovibos moschatus) in Northeast Greenland. The results show that juvenile animals can be particularly vulnerable to changes in their environment, and that this is mirrored to different degrees in the spatio-temporal dynamics of the three populations. Adverse weather conditions, acting either directly or mediated through access to and quality of vegetation, experienced by young early in life, or even by their dams during pregnancy, can lead to reduced growth, lower survival and reduced reproductive performance later in life. The influence of current climatic variation, and the predictions of how local weather conditions may change over time, differs between the three sites, resulting in potentially different responses in the three populations. Aanes R, Saether BE and Øritsland NA. 2000. Fluctuations of an introduced population of Svalbard reindeer: the effects of density dependence and climatic variation. Ecography

  6. Oxidative stress and life histories: unresolved issues and current needs.

    Science.gov (United States)

    Speakman, John R; Blount, Jonathan D; Bronikowski, Anne M; Buffenstein, Rochelle; Isaksson, Caroline; Kirkwood, Tom B L; Monaghan, Pat; Ozanne, Susan E; Beaulieu, Michaël; Briga, Michael; Carr, Sarah K; Christensen, Louise L; Cochemé, Helena M; Cram, Dominic L; Dantzer, Ben; Harper, Jim M; Jurk, Diana; King, Annette; Noguera, Jose C; Salin, Karine; Sild, Elin; Simons, Mirre J P; Smith, Shona; Stier, Antoine; Tobler, Michael; Vitikainen, Emma; Peaker, Malcolm; Selman, Colin

    2015-12-01

    Life-history theory concerns the trade-offs that mold the patterns of investment by animals between reproduction, growth, and survival. It is widely recognized that physiology plays a role in the mediation of life-history trade-offs, but the details remain obscure. As life-history theory concerns aspects of investment in the soma that influence survival, understanding the physiological basis of life histories is related, but not identical, to understanding the process of aging. One idea from the field of aging that has gained considerable traction in the area of life histories is that life-history trade-offs may be mediated by free radical production and oxidative stress. We outline here developments in this field and summarize a number of important unresolved issues that may guide future research efforts. The issues are as follows. First, different tissues and macromolecular targets of oxidative stress respond differently during reproduction. The functional significance of these changes, however, remains uncertain. Consequently there is a need for studies that link oxidative stress measurements to functional outcomes, such as survival. Second, measurements of oxidative stress are often highly invasive or terminal. Terminal studies of oxidative stress in wild animals, where detailed life-history information is available, cannot generally be performed without compromising the aims of the studies that generated the life-history data. There is a need therefore for novel non-invasive measurements of multi-tissue oxidative stress. Third, laboratory studies provide unrivaled opportunities for experimental manipulation but may fail to expose the physiology underpinning life-history effects, because of the benign laboratory environment. Fourth, the idea that oxidative stress might underlie life-history trade-offs does not make specific enough predictions that are amenable to testing. Moreover, there is a paucity of good alternative theoretical models on which contrasting

  7. Young mothers with a history of substance use - establishing arenas of comfort.

    DEFF Research Database (Denmark)

    Hecksher, Dorte

    to different staff members (such as social workers, visiting nurses, and addiction counsellors). Staff members, who focus on these women's new roles as responsible parents, but also on aspects related to their history of drug (mis-)use. Usually the combination of being a young mother with a history...... Based on a qualitative study of pregnant and parenting women (n=26) with a history of substance use this paper focuses on a sub-sample of younger women, aged 19 -23 at the time of pregnancy. It focuses on these women's perception of becoming a mother and their perception of the relation...... of substance use, lacking formal education, having poor economic resources and with the prospect of becoming a single mother, is seen as rather negative conditions for making sustainable positive life-changes. But it is our hypothesis that some of the women in the study succeed in leaving their drug...

  8. Life Satisfaction among Young Adults from Rural Families.

    Science.gov (United States)

    Wilson, Stephan M.; Peterson, Gary W.

    1988-01-01

    Examined possible predictors of life satisfaction among 322 low-income young adults from rural Appalachia. Both objective and subjective conditions of life were predictors of life satisfaction: financial resources, self-esteem, and proximity to childhood home were positive predictors; frustrations about limited job opportunities and community size…

  9. Early Life Histories of Fishes: New Developmental, Ecological and ...

    African Journals Online (AJOL)

    ontogeny and life history models revisited' which is an unabridged .... Hamburg, Germany, in August 1984. The papers are ..... Cambridge University Press, Cambridge, New York and ... lessons to be learnt from the well-illustrated keys and for.

  10. Can understanding squid life-history strategies and recruitment ...

    African Journals Online (AJOL)

    Can understanding squid life-history strategies and recruitment improve management? ... range of potentially limiting conditions in different years, they store genetic diversity and stabilize recruitment in time. ... AJOL African Journals Online.

  11. Phytoplankton models and life history strategies | Eilertsen | African ...

    African Journals Online (AJOL)

    Phytoplankton models and life history strategies. ... Chaetoceros bloom of the growth season usually starts in mid March, initiated by C. socialis. ... in some species, inoculation events are controlled by endogenous biological clocks.

  12. Evolution of reproductive life histories in island birds worldwide.

    Science.gov (United States)

    Covas, Rita

    2012-04-22

    Island environments typically share characteristics such as impoverished biotas and less-seasonal climates, which should be conducive to specific adaptations by organisms. However, with the exception of morphological studies, broad-scale tests of patterns of adaptation on islands are rare. Here, I examine reproductive patterns in island birds worldwide. Reproductive life histories are influenced by latitude, which could affect the response to insularity; therefore, I additionally test this hypothesis. Island colonizers showed mostly bi-parental care, but there was a significant increase in cooperative breeding on islands. Additionally, I found support for previous suggestions of reduced fecundity, longer developmental periods and increased investment in young on islands. However, clutch size increased with latitude at a rate nearly five times faster on the mainland than on the islands revealing a substantially stronger effect of insularity at higher latitudes. Latitude and insularity may also interact to determine egg volume and incubation periods, but these effects were less clear. Analyses of reproductive success did not support an effect of reduced nest predation as a driver of reproductive change, but this requires further study. The effect of latitude detected here suggests that the evolutionary changes associated with insularity relate to environmental stability and improved adult survival.

  13. Life histories of potamodromous fishes [Chapter 4

    Science.gov (United States)

    Russell F. Thurow

    2016-01-01

    Potamodromous fishes move and complete their life cycle entirely within freshwater. Myers (1949) proposed the term potamodromous to distinguish freshwater migratory fishes from diadromous fishes, which migrate between the sea and freshwater and oceanodromous fishes that migrate wholly within the sea. Diadromous fishes include anadromous, catadromous and amphidromous...

  14. The effect of life expectancy on aggression and generativity: a life history perspective.

    Science.gov (United States)

    Dunkel, Curtis S; Mathes, Eugene; Papini, Dennis R

    2010-09-23

    Following a model that is inclusive of both dispositional and situational influences on life-history behaviors and attitudes, the effect of life expectancies on aggression and generativity was examined. Consistent with the hypotheses it was found that shorter life expectancies led to an increase in the desire to aggress and a decrease in the desire to engage in generative behaviors. The results are discussed in terms of how life history theory can be used to frame research on person-situation interactions.

  15. Fertility History and Cognition in Later Life.

    Science.gov (United States)

    Read, Sanna L; Grundy, Emily M D

    2017-10-01

    To investigate the association between fertility history and cognition in older men and women. We analyzed associations between number of children (parity) and timing of births with level and change in cognition among 11,233 men and women aged 50+ in England using latent growth curve models. Models were adjusted for age, socioeconomic position, health, depressive symptoms, control, social contacts, activities, and isolation. Low (0-1 child) and high parity (3+ children) compared to medium parity (2 children) were associated with poorer cognitive functioning, as was an early age at entry to parenthood (cognition. Late motherhood (>35) was associated with better cognitive function. Associations between fertility history and cognition were to large extent accounted for socioeconomic position, partly because this influenced health and social engagement. Poorer cognition in childless people and better cognition among mothers experiencing child birth at higher ages suggest factors related to childbearing/rearing that are beneficial for later cognitive functioning, although further research into possible earlier selection factors is needed. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America.

  16. Life-history variation of a neotropical thrush challenges food limitation theory

    Science.gov (United States)

    Ferretti, V.; Llambias, P.E.; Martin, T.E.

    2005-01-01

    Since David Lack first proposed that birds rear as many young as they can nourish, food limitation has been accepted as the primary explanation for variation in clutch size and other life-history traits in birds. The importance of food limitation in life-history variation, however, was recently questioned on theoretical grounds. Here, we show that clutch size differences between two populations of a neotropical thrush were contrary to expectations under Lack's food limitation hypothesis. Larger clutch sizes were found in a population with higher nestling starvation rate (i.e. greater food limitation). We experimentally equalized clutches between populations to verify this difference in food limitation. Our experiment confirmed greater food limitation in the population with larger mean clutch size. In addition, incubation bout length and nestling growth rate were also contrary to predictions of food limitation theory. Our results demonstrate the inability of food limitation to explain differences in several life-history traits: clutch size, incubation behaviour, parental feeding rate and nestling growth rate. These life-history traits were better explained by inter-population differences in nest predation rates. Food limitation may be less important to life history evolution in birds than suggested by traditional theory. ?? 2005 The Royal Society.

  17. Life history theory predicts fish assemblage response to hydrologic regimes.

    Science.gov (United States)

    Mims, Meryl C; Olden, Julian D

    2012-01-01

    The hydrologic regime is regarded as the primary driver of freshwater ecosystems, structuring the physical habitat template, providing connectivity, framing biotic interactions, and ultimately selecting for specific life histories of aquatic organisms. In the present study, we tested ecological theory predicting directional relationships between major dimensions of the flow regime and life history composition of fish assemblages in perennial free-flowing rivers throughout the continental United States. Using long-term discharge records and fish trait and survey data for 109 stream locations, we found that 11 out of 18 relationships (61%) tested between the three life history strategies (opportunistic, periodic, and equilibrium) and six hydrologic metrics (two each describing flow variability, predictability, and seasonality) were statistically significant (P history strategies, with 82% of all significant relationships observed supporting predictions from life history theory. Specifically, we found that (1) opportunistic strategists were positively related to measures of flow variability and negatively related to predictability and seasonality, (2) periodic strategists were positively related to high flow seasonality and negatively related to variability, and (3) the equilibrium strategists were negatively related to flow variability and positively related to predictability. Our study provides important empirical evidence illustrating the value of using life history theory to understand both the patterns and processes by which fish assemblage structure is shaped by adaptation to natural regimes of variability, predictability, and seasonality of critical flow events over broad biogeographic scales.

  18. Life history strategy of the honey bee, Apis mellifera.

    Science.gov (United States)

    Seeley, Thomas D

    1978-01-01

    The feral honey bee queens (colonies) of central New York State (USA) show a K-type life history strategy. Their demographic characteristics include low early life mortality, low reproductive rate, long lifespan, high population stability and repeated reproductions. Identifying the life history strategy of these bees reveals the general pattern of selection for competitive ability, rather than productivity, which has shaped their societies. Selection for competitive power explains the adaptiveness (compared with alternatives found in many other insect societies) of the large perennial colonies, infrequent but expensive offspring, and efficient foraging which characterize the social organization of these bees.

  19. Life history of a large flake biface

    Science.gov (United States)

    Baena Preysler, Javier; Torres Navas, Concepción; Sharon, Gonen

    2018-06-01

    Bifaces, primarily handaxes and cleavers, are the hallmark of the Acheulian techno-complex lithic industry. They spread across Africa and Eurasia during the Early to Middle Pleistocene. While many attempts have been made to define and describe the typology and technology of these tools, most focus on a single stage in their manufacture and usage, from quarry to discard. These attempts are fragmented, primarily due to the fact that at no single site are all stages of biface manufacture and use represented. An additional factor that appears to impede attempts to present the full "life cycle" of bifaces is the view of all Acheulian assemblages as belonging to a single cultural entity. While all assemblages belong to the same techno-complex, distinct stages and phases should be recognized, each different in typology, technology, and probably also in chronology. This research focuses on the large flake stage of the Acheulian. Data accumulated over many years of research from different regions are analyzed together in an attempt to present a holistic view of the life cycle of a biface. The study of particular Acheulian sites from the Levant and Western Europe enables us to reconstruct all stages of the biface, from raw material exploitation to final discard. The result is a model more comprehensive and precise than those suggested previously for understanding the Large Flake Acheulian.

  20. Star-formation history of very young clusters

    International Nuclear Information System (INIS)

    Stahler, S.W.

    1985-01-01

    The popular idea that star formation has proceeded sequentially from lowest to highest mass members in open clusters is examined critically. For extremely young clusters, such as NGC 2264 and NGC 6530, this sequential hypothesis is a consequence of the assignment of pre-main-sequence contraction ages to all member stars. However, such ages yield a formation history which is implausible from a physical point of view, since the critical time for the onset of formation at any stellar mass is equal to the pre-main-sequence contraction time for that mass. Moreover, these ages are in conflict with the strong observational evidence that a substantial fraction of cluster members have already reached the main sequence. After reconsideration of the probable main-sequence members, the stellar ages in NGC 2264 and NGC 6530 are consistent with a variety of formation histories, and, in particular, with the view that all stellar masses form in approximately the same interval of time within a given cluster, i.e., that there is no mass-age correlation. A notion closely related to the sequential hypothesis, that the total star-formation rate increases exponentially with time, is subject to the same criticism

  1. Life Strategies of Young People: Sociological Research Experience

    Directory of Open Access Journals (Sweden)

    Lyubov’ Borisovna Osipova

    2016-09-01

    Full Text Available Modern reality is the world of formation of various life prospects of a young person. The relevance of the topic depends, firstly, on insufficient sociological research into the mechanism of formation and realization of life strategies of modern youth; and, secondly, on the need to substantiate the sociological concept of youth life strategies in terms of professional self-determination with regard to its social and group characteristics. In this context, young people as the most active social group are of great interest to the authors who consider them a research target. Due to the transitivity of a social status and the incomplete processes of social maturity formation young people need a targeted design of their future. The sociological analysis of the issue involves a clarification of the concept of “life strategy” at the conceptual level (A.A. Volokitin, S.N. Ikonnikova, E.I. Golovakha, Yu.A. Zubok, V.T. Lisovsky, M.N. Rutkevich, G.V. Leonidova, K.A. Ustinova, etc.. The article presents the author’s definition of “life strategies”, which is a dynamic system of perspective individual orientation aimed at designing one’s life in the future. At the same time the results of the author’s sociological research are presented, including a standardized interview, questionnaires, which provide an opportunity to form an idea about the living choices of young people living in Yugra. The declining influence of social institutions and the emerging opportunities for developing their life prospects on their own challenges young people to select their life targets and ways of their implementation independently. The article justifies the necessity of intensified activation of new forms of young students’ management when planning their life trajectory. Life strategies disclose its content in specific life situations associated with choice. The key choice is the career choice of young people which directly depends on the socio

  2. Life-History Patterns of Lizards of the World.

    Science.gov (United States)

    Mesquita, Daniel O; Costa, Gabriel C; Colli, Guarino R; Costa, Taís B; Shepard, Donald B; Vitt, Laurie J; Pianka, Eric R

    2016-06-01

    Identification of mechanisms that promote variation in life-history traits is critical to understand the evolution of divergent reproductive strategies. Here we compiled a large life-history data set (674 lizard populations, representing 297 species from 263 sites globally) to test a number of hypotheses regarding the evolution of life-history traits in lizards. We found significant phylogenetic signal in most life-history traits, although phylogenetic signal was not particularly high. Climatic variables influenced the evolution of many traits, with clutch frequency being positively related to precipitation and clutches of tropical lizards being smaller than those of temperate species. This result supports the hypothesis that in tropical and less seasonal climates, many lizards tend to reproduce repeatedly throughout the season, producing smaller clutches during each reproductive episode. Our analysis also supported the hypothesis that viviparity has evolved in lizards as a response to cooler climates. Finally, we also found that variation in trait values explained by clade membership is unevenly distributed among lizard clades, with basal clades and a few younger clades showing the most variation. Our global analyses are largely consistent with life-history theory and previous results based on smaller and scattered data sets, suggesting that these patterns are remarkably consistent across geographic and taxonomic scales.

  3. Hypertension in Asymptomatic, Young Medical Students with Parental History of Hypertension

    Directory of Open Access Journals (Sweden)

    Simran Sidhu

    2017-11-01

    Full Text Available Introduction: Family history of hypertension in medical students is an important, non-modifiable risk factor for hypertension in future. Aim: To determine the prevalence of sustained hypertension in young asymptomatic medical students with a parental history of hypertension. Materials and Methods: A cross-sectional study was conducted in a medical college of Dehradun. A total of 104 medical students with parental history of hypertension (Group A and 100 medical students without a parental history of hypertension (Group B were included. Electronically blood pressures were recorded on two separate occasions at an interval of 15 days. Comparison was done using Chi-square test/Likelihood ratio, Un-paired t-test and ANCOVA. Results: Overall, Group A had significantly higher percentage of prehypertensive (56.7% and hypertensive (17.3% students as compared to Group B which were 19% and 1%, respectively. Group A students had significantly higher Systolic Blood Pressure (SBP and Diastolic Blood Pressure (DBP as compared to Group B, even after controlling for the differences in Body Mass Index (BMI and gender (p<0.001. Conclusion: Hypertension was significantly higher in asymptomatic, healthy medical students with parental history of hypertension as compared to those with normotensive parents. We need to orient medical students to improve their knowledge, attitude and lifestyle practices early in life to prevent, treat hypertension and prevent its subsequent morbidity and mortality.

  4. Work Identity and Contradictory Experiences of Welfare Workers in a Life-history Perspective

    DEFF Research Database (Denmark)

    Dybbroe, Betina

    2012-01-01

    Transformation of the welfare sectors challenge professional identities of care and welfare workers in Scandinavia. At the same time welfare and care workers take part in these changes and are changed in the psycho-social setting of the workplace. This article presents research about care work...... in nursing and involves a young nurse in scenes of the hospital, where gendered life history is re-enacted and present in a gendered work life with fragile possibilities of identification . Social dynamics interact with subjective dynamics in ways that illuminate not only habitual and creative orientations...

  5. Implications of life-history strategies for obesity.

    Science.gov (United States)

    Maner, Jon K; Dittmann, Andrea; Meltzer, Andrea L; McNulty, James K

    2017-08-08

    The association between low socioeconomic status (SES) and obesity is well documented. In the current research, a life history theory (LHT) framework provided an explanation for this association. Derived from evolutionary behavioral science, LHT emphasizes how variability in exposure to unpredictability during childhood gives rise to individual differences in a range of social psychological processes across the life course. Consistent with previous LHT research, the current findings suggest that exposure to unpredictability during childhood (a characteristic common to low SES environments) is associated with the adoption of a fast life-history strategy, one marked by impulsivity and a focus on short-term goals. We demonstrate that a fast life-history strategy, in turn, was associated with dysregulated weight-management behaviors (i.e., eating even in the absence of hunger), which were predictive of having a high body mass index (BMI) and being obese. In both studies, findings held while controlling for participants' current socioeconomic status, suggesting that obesity is rooted in childhood experiences. A serial mediation model in study 2 confirmed that effects of childhood SES on adult BMI and obesity can be explained in part by exposure to unpredictability, the adoption of a fast life-history strategy, and dysregulated-eating behaviors. These findings suggest that weight problems in adulthood may be rooted partially in early childhood exposure to unpredictable events and environments. LHT provides a valuable explanatory framework for understanding the root causes of obesity.

  6. Labor market participation among young adults: an event history analysis.

    Science.gov (United States)

    Johnson, R J; Herring, C

    1989-09-01

    This study models culture of poverty explanations, earlier experiences that tend to restrict opportunities, demographic effects representing differential rates of participation by social groups, and health and marijuana use variables indicating the influence of individual life- style differences as predictors of the rate of labor market entry, promotion, and dismissal among subjects from early adolescence to young adulthood. The data are drawn from the 1st and 4th waves of a 4-wave panel of half the 1971 Houston, Texas, Independent School District 7th grade born in 1958. The findings indicate that those who believe most in the efficacy of alternatives to conventional social and economic institutions and those who expect to benefit least are most likely to have higher rates of participation. This higher rate of participation is significantly greater for earlier years and contradicts predictions of a culture of poverty theory. 1 opportunity-structure variable, poor grades, significantly increases the rate of entry into the labor market primarily because it represents the inability of individuals to pursue advanced education prior to labor market entry. Education reduces overall rates of labor market entry for a young adult cohort by delaying labor market entry. The strong relationship between drug use and unemployment may be due to motivation, impaired ability, probability of failure, or increased time to use drugs. The findings also indicate that females are more capable overall of performing their jobs and getting along with co-workers but are less likely to be promoted. Finally, those who have been sanctioned or disadvantaged within the institutions that define and enforce the norms of the economic opportunity structure are significantly more likely to enter the labor market earlier and continue to have higher rates of negative experiences, such as dismissal, within those institutions.

  7. A new view of avian life-history evolution tested on an incubation paradox.

    Science.gov (United States)

    Martin, Thomas E

    2002-02-07

    Viewing life-history evolution in birds based on an age-specific mortality framework can explain broad life-history patterns, including the long incubation periods in southern latitudes documented here. I show that incubation periods of species that are matched phylogenetically and ecologically between Argentina and Arizona are longer in Argentina. Long incubation periods have mystified scientists because they increase the accumulated risk of time-dependent mortality to young without providing a clear benefit. I hypothesize that parents of species with low adult mortality accept increased risk of mortality to their young from longer incubation if this allows reduced risk of mortality to themselves. During incubation, songbird parents can reduce risk of mortality to themselves by reducing nest attentiveness (percentage of time on the nest). Here I show that parents of species with lower adult mortality exhibit reduced nest attentiveness and that lower attentiveness is associated with longer incubation periods. However, the incubation period is also modified by juvenile mortality. Clutch size variation is also strongly correlated with age-specific mortality. Ultimately, adult and juvenile mortality explain variation in incubation and other life-history traits better than the historical paradigm.

  8. Early Life Trauma Exposure and Stress Sensitivity in Young Children

    OpenAIRE

    Grasso, Damion J.; Ford, Julian D.; Briggs-Gowan, Margaret J.

    2012-01-01

    Objective The current study replicates and extends work with adults that highlights the relationship between trauma exposure and distress in response to subsequent, nontraumatic life stressors. Methods The sample included 213 2–4-year-old children in which 64.3% had a history of potential trauma exposure. Children were categorized into 4 groups based on trauma history and current life stress. Results In a multivariate analysis of variance, trauma-exposed children with current life stressors h...

  9. Explaining Well-Being over the Life Cycle: A Look at Life Transitions during Young Adulthood

    OpenAIRE

    Switek, Malgorzata

    2013-01-01

    Early adulthood is a time of important transitions that shape the future of young adults. How do these transitions affect well-being, and to what degree can they account for the life satisfaction path followed during young adulthood? To answer these questions, longitudinal data from the Swedish Young Adult Panel Study are used for three cohorts interviewed in 1999, 2003, and 2009. Four age intervals covering ages 22 through 40 are constructed. The well-being changes and the main transitions u...

  10. Can understanding squid life-history strategies and recruitment ...

    African Journals Online (AJOL)

    Current views of the links between life-history strategies and recruitment processes in fish are contrasted with the pattern emerging for squid. A general perspective is that the roles of space and time are reversed in the two groups, suggesting that management strategies also should differ. The space/time reversal appears to ...

  11. Life-history parameters of white stumpnose Rhabdosargus ...

    African Journals Online (AJOL)

    Life-history parameters of white stumpnose Rhabdosargus globiceps (Pisces: Sparidae) in Saldanha Bay, South Africa, with evidence of stock separation. ... Seasonal variation in the condition index suggests a slightly greater investment in reproduction by males than females. Females grew slightly faster than males and ...

  12. A Brief History of Family Life Education in Romania

    Science.gov (United States)

    Momanu, Mariana; Popa, Nicoleta Laura; Samoila, Magda-Elena

    2018-01-01

    Starting from the state of conceptual diversity, semantic ambiguity, and poor connection of family life education practices to current policies and theoretical models in Romania, our study aims at understanding the underlying meanings of these issues by recourse to the history of approaches in the field. To this purpose, we carried out a…

  13. On the Psychometric Study of Human Life History Strategies.

    Science.gov (United States)

    Richardson, George B; Sanning, Blair K; Lai, Mark H C; Copping, Lee T; Hardesty, Patrick H; Kruger, Daniel J

    2017-01-01

    This article attends to recent discussions of validity in psychometric research on human life history strategy (LHS), provides a constructive critique of the extant literature, and describes strategies for improving construct validity. To place the psychometric study of human LHS on more solid ground, our review indicates that researchers should (a) use approaches to psychometric modeling that are consistent with their philosophies of measurement, (b) confirm the dimensionality of life history indicators, and (c) establish measurement invariance for at least a subset of indicators. Because we see confirming the dimensionality of life history indicators as the next step toward placing the psychometrics of human LHS on more solid ground, we use nationally representative data and structural equation modeling to test the structure of middle adult life history indicators. We found statistically independent mating competition and Super-K dimensions and the effects of parental harshness and childhood unpredictability on Super-K were consistent with past research. However, childhood socioeconomic status had a moderate positive effect on mating competition and no effect on Super-K, while unpredictability did not predict mating competition. We conclude that human LHS is more complex than previously suggested-there does not seem to be a single dimension of human LHS among Western adults and the effects of environmental components seem to vary between mating competition and Super-K.

  14. Book Review: Evolutionary Ecology of Birds: Life Histories, Mating ...

    African Journals Online (AJOL)

    Abstract. Book Title: Evolutionary Ecology of Birds: Life Histories, Mating Systems and Extinction. Book Authors: P.M. Bennett & I.P.F. Owens. Oxford University. Press. 2002. Pp. 272. Price £24.95 (paperback). ISBN 0 19 851089 6.

  15. The ecology of life history evolution : genes, individuals and populations

    NARCIS (Netherlands)

    Visser, M.E.

    2013-01-01

    Natural selection shapes the life histories of organisms. The ecological interactions of these organisms with their biotic and abiotic environment shape the selection pressure on their phenotypes while their genetics determine how fast this selection leads to adaptation to their environment. The

  16. Life history traits of Bathyclarias nyasensis (Siluroidei) in Lake Malawi

    African Journals Online (AJOL)

    Life history traits, including age, growth, reproduction and diet of Bathyclarias nyasensis from Lake Malawi were studied between December 1996 and November 1998. Owing to reabsorp tion of pectoral spines with increasing fish size, and the relatively low number of spines that could be aged reliably, only otoliths were ...

  17. Plant life history and above–belowground interactions

    NARCIS (Netherlands)

    Deyn, de Gerlinde

    2017-01-01

    The importance of above–belowground interactions for plant growth and community dynamics became clear in the last decades, whereas the numerous studies on plant life history improved our knowledge on eco-evolutionary dynamics. However, surprisingly few studies have linked both research fields

  18. On the Psychometric Study of Human Life History Strategies

    Directory of Open Access Journals (Sweden)

    George B. Richardson

    2017-02-01

    Full Text Available This article attends to recent discussions of validity in psychometric research on human life history strategy (LHS, provides a constructive critique of the extant literature, and describes strategies for improving construct validity. To place the psychometric study of human LHS on more solid ground, our review indicates that researchers should (a use approaches to psychometric modeling that are consistent with their philosophies of measurement, (b confirm the dimensionality of life history indicators, and (c establish measurement invariance for at least a subset of indicators. Because we see confirming the dimensionality of life history indicators as the next step toward placing the psychometrics of human LHS on more solid ground, we use nationally representative data and structural equation modeling to test the structure of middle adult life history indicators. We found statistically independent mating competition and Super-K dimensions and the effects of parental harshness and childhood unpredictability on Super-K were consistent with past research. However, childhood socioeconomic status had a moderate positive effect on mating competition and no effect on Super-K, while unpredictability did not predict mating competition. We conclude that human LHS is more complex than previously suggested—there does not seem to be a single dimension of human LHS among Western adults and the effects of environmental components seem to vary between mating competition and Super-K.

  19. Life-History and Developmental Antecedents of Female Vocational Preferences.

    Science.gov (United States)

    Reichel, Laura S.; Muchinsky, Paul M.

    1995-01-01

    A group of 296 female undergraduates completed the Strong Interest Inventory, Biographical Questionnaire, Bem Sex-Role Inventory, and Self-Esteem Inventory. Life history was a better predictor of vocational interests than either sex-role orientation or self-esteem. The only significant exception was that Femininity correlated with interest in…

  20. Comparison of the population structure and life-history parameters ...

    African Journals Online (AJOL)

    Blacktail seabream Diplodus capensis were sampled from proximate (10 km apart) exploited and unexploited areas in southern Angola to compare their population structures and life-history parameters. Females dominated the larger size and older age classes in the unexploited area. In the exploited area the length and ...

  1. Variations in morphological and life-history traits under extreme ...

    Indian Academy of Sciences (India)

    Two extremely stressful temperatures (18°C and 32°C) and one standard ... and non-stressful environments on the morphological and life-history traits in males and ... Genetics Laboratory, Department of Zoology, Banaras Hindu University, ...

  2. Paternal effects on early life history traits in Northwest Atlantic cod, Gadus morhua

    DEFF Research Database (Denmark)

    Kroll, M.-M.; Peck, M.A.; Butts, Ian A.E.

    2013-01-01

    It is important to understand parental effects on early life history of fish as manifested, for example, in individual fitness of offspring. Immediately after fertilization, parental contributions (both genetic and non-genetic) to embryos will affect larval ontogeny, physiology, morphology...... and survival. In marine fish, rates of natural mortality are highest during early life and are negatively correlated with rates of growth and body size. In these early life stages (eggs, larvae, young juveniles) subtle differences in mortality can cause large differences in recruitment and year-class success...... and can serve as important sources of variation during early life stages in fishes. Overall, these findings have implications for furthering the understanding of recruitment variability and can be used to optimize reproductive output for the aquaculture industry. In addition, the data suggests...

  3. Identity and School History: The Perspective of Young People from the Netherlands and England

    Science.gov (United States)

    Grever, Maria; Haydn, Terry; Ribbens, Kees

    2008-01-01

    The article presents the findings from a survey of over 400 young people in metropolitan areas in the Netherlands and England concerning their views on identity and school history. The research explored pupils' ideas about which facets of history were of interest to them, what history they believed should be taught in schools, and their views on…

  4. Bringing history to life: simulating landmark experiments in psychology.

    Science.gov (United States)

    Boynton, David M; Smith, Laurence D

    2006-05-01

    The course in history of psychology can be challenging for students, many of whom enter it with little background in history and faced with unfamiliar names and concepts. The sheer volume of material can encourage passive memorization unless efforts are made to increase student involvement. As part of a trend toward experiential history, historians of science have begun to supplement their lectures with demonstrations of classic physics experiments as a way to bring the history of science to life. Here, the authors report on computer simulations of five landmark experiments from early experimental psychology in the areas of reaction time, span of attention, and apparent motion. The simulations are designed not only to permit hands-on replication of historically important results but also to reproduce the experimental procedures closely enough that students can gain a feel for the nature of early research and the psychological processes being studied.

  5. Life History Trade-Offs Modulate the Speed of Senescence

    DEFF Research Database (Denmark)

    Salguero-Gómez, Roberto; Jones, Owen

    2017-01-01

    that the speed of senescence varies dramatically across the Tree of Life and that it has a moderate phylogenetic signal when considering both plants and animals but that this signal is stronger in animals than in plants, indicating that the strength of selection on the trait may differ between kingdoms. We next...... examined the speed of senescence at two taxonomic levels: comparing kingdoms, with plants more likely to postpone senescence than animals, and, when the data allowed for it, comparing taxonomic classes, where we found that pine trees are particularly slow to senesce, followed by reptiles and sponges. Most...... puzzling and worthy of investigation in itself. We used two open-data repositories of high-quality demographic information for animals and plants to present a novel overview of the degree of variation in life-history strategies and their component life-history traits, including the speed of senescence...

  6. Telling Modernization: Three Voices. Life History, Gender and the Discourse of Modernization. Roskilde University Life History Project Paper.

    Science.gov (United States)

    Anderson, Linda

    The relationship between life history, gender, and the discourse of modernization was examined from the perspective of a researcher with extensive experience performing evaluations about modernization within human services in Denmark. Three stories about site-based management in two human service institutionsa youth center and a boarding school…

  7. Towards cancer-aware life-history modelling.

    Science.gov (United States)

    Kokko, Hanna; Hochberg, Michael E

    2015-07-19

    Studies of body size evolution, and life-history theory in general, are conducted without taking into account cancer as a factor that can end an organism's reproductive lifespan. This reflects a tacit assumption that predation, parasitism and starvation are of overriding importance in the wild. We argue here that even if deaths directly attributable to cancer are a rarity in studies of natural populations, it remains incorrect to infer that cancer has not been of importance in shaping observed life histories. We present first steps towards a cancer-aware life-history theory, by quantifying the decrease in the length of the expected reproductively active lifespan that follows from an attempt to grow larger than conspecific competitors. If all else is equal, a larger organism is more likely to develop cancer, but, importantly, many factors are unlikely to be equal. Variations in extrinsic mortality as well as in the pace of life--larger organisms are often near the slow end of the fast-slow life-history continuum--can make realized cancer incidences more equal across species than what would be observed in the absence of adaptive responses to cancer risk (alleviating the so-called Peto's paradox). We also discuss reasons why patterns across species can differ from within-species predictions. Even if natural selection diminishes cancer susceptibility differences between species, within-species differences can remain. In many sexually dimorphic cases, we predict males to be more cancer-prone than females, forming an understudied component of sexual conflict.

  8. The Good Life: Empowering Young Adults with Intellectual Disabilities through Everyday Life Information

    Science.gov (United States)

    Hanson-Baldauf, Dana

    2011-01-01

    Although "the good life" is a concept not easily defined or agreed upon, without a doubt it is something people want and strive to achieve. For young adults with intellectual disabilities (ID), efforts toward the good life are often hindered by harsh realities and numerous challenges encountered on the road to adulthood. School librarians can play…

  9. A psycho-societal approach to life histories

    DEFF Research Database (Denmark)

    Olesen, Henning Salling

    2016-01-01

    Life histories represent lived lives past, present and anticipated future. As such they are interpretations of individuals’ experiences of the way in which societal dynamics take place in the individual body and mind, either by the individual him/herself or by another biographer. I have been...... particularly interested in the relations between the culturally mediated and the sensory/bodily aspects of experience processes because this is the boundary zones of knowledge and seat of the dynamics of learning. My psycho-societal approach was developing from interpreting autobiographical and later certain...... other forms of language interactive material as moments of life history, i.e. it is basically a hermeneutic approach. Talking about a psycho-societal approach indicates the ambition of attacking the dichotomy of the social and the psychic, both in the interpretation procedure and in some main...

  10. Life history strategy and the HEXACO personality dimensions

    OpenAIRE

    Manson, JH

    2015-01-01

    Although several studies have linked Life History Strategy (LHS) variation with variation in the Five Factor Model personality dimensions, no published research has explored the relationship of LHS to the HEXACO personality dimensions. The theoretically expected relationship of the HEXACO Emotionality factor to LHS is unclear. The results of two studies (N = 641) demonstrated that LHS indicators form part of a factor along with HEXACO Extraversion, Agreeableness, Conscientiousness, and (margi...

  11. Towards cancer-aware life-history modelling

    OpenAIRE

    Kokko, Hanna; Hochberg, Michael

    2015-01-01

    Studies of body size evolution, and life-history theory in general, are conducted without taking into account cancer as a factor that can end an organism’s reproductive lifespan. This reflects a tacit assumption that predation, parasitism and starvation are of overriding importance in the wild. We argue here that even if deaths directly attributable to cancer are a rarity in studies of natural populations, it remains incorrect to infer that cancer has not been of importance in shaping observe...

  12. Height among Women is Curvilinearly Related to Life History Strategy

    Directory of Open Access Journals (Sweden)

    Abraham P. Buunk

    2009-10-01

    Full Text Available It was hypothesized that women of medium height would show a more secure, long-term mating pattern characterized by less jealousy, less intrasexual competition and a “slower” life history strategy. In three samples of female undergraduate students clear support was found for these hypotheses. In Study 1, among 120 participants, height was curvilinearly related to well-established measures of possessive and reactive jealousy, with women of medium height being less jealous than tall as well as short women. In Study 2, among 40 participants, height was curvilinearly related to intrasexual competition, with women of medium height being less competitive towards other women than tall as well as short women. In Study 3, among 299 participants, height was curvilinearly related to the Mini-K, a well-validated measure of “slower” life history strategy, with women of medium height having a slower life history strategy than tall as well as short women. The results suggest that women of medium height tend to follow a different mating strategy than either tall or short women. Various explanations and implications of these results are discussed.

  13. Sleep-Wake State Tradeoffs, Impulsivity and Life History Theory

    Directory of Open Access Journals (Sweden)

    Alissa A. Miller

    2012-04-01

    Full Text Available Evolutionary ecological theory predicts that sleep-wake state tradeoffs may be related to local environmental conditions and should therefore correlate to alterations in behavioral life history strategies. It was predicted that firefighters who slept more and reported better quality sleep on average would exhibit lower impulsivity inclinations related to slower life history trajectories. UPPS impulsivity scores and self-reported sleep averages were analyzed and indicated a negative association between sleep variables and urgency and a positive association with premeditation. Perseverance, and in some cases premeditation, however, disclosed an unpredicted marginally significant positive association between increased and emergency nighttime waking-related sleep deprivation. Sensation seeking was not associated with sleep variables, but was strongly associated with number of biological children. This research contributes to understanding the implications of human sleep across ecological and behavioral contexts and implies further research is necessary for constructing evolutionarily oriented measures of impulsivity inclination and its meaning in the context of life history strategies.

  14. The life-history basis of behavioural innovations.

    Science.gov (United States)

    Sol, Daniel; Sayol, Ferran; Ducatez, Simon; Lefebvre, Louis

    2016-03-19

    The evolutionary origin of innovativeness remains puzzling because innovating means responding to novel or unusual problems and hence is unlikely to be selected by itself. A plausible alternative is considering innovativeness as a co-opted product of traits that have evolved for other functions yet together predispose individuals to solve problems by adopting novel behaviours. However, this raises the question of why these adaptations should evolve together in an animal. Here, we develop the argument that the adaptations enabling animals to innovate evolve together because they are jointly part of a life-history strategy for coping with environmental changes. In support of this claim, we present comparative evidence showing that in birds, (i) innovative propensity is linked to life histories that prioritize future over current reproduction, (ii) the link is in part explained by differences in brain size, and (iii) innovative propensity and life-history traits may evolve together in generalist species that frequently expose themselves to novel or unusual conditions. Combined with previous evidence, these findings suggest that innovativeness is not a specialized adaptation but more likely part of a broader general adaptive system to cope with changes in the environment. © 2016 The Author(s).

  15. The History and Timing of Depression Onset as Predictors of Young Adult Self-Esteem

    Science.gov (United States)

    Gayman, Mathew D.; Lloyd, Donald A.; Ueno, Koji

    2011-01-01

    Depression often emerges early in the lifecourse and is consistently shown to be associated with poor self-esteem. The 3 main objectives of the current study are to (1) evaluate the association between a history major depression and self-esteem in young adulthood, (2) assess the relationship between timing of depression onset and young adult…

  16. Healthy Behaviors and Lifestyles in Young Adults with a History of Developmental Disabilities

    Science.gov (United States)

    Rurangirwa, Jacqueline; Braun, Kim Van Naarden; Schendel, Diana; Yeargin-Allsopp, Marshalyn

    2006-01-01

    Objective: Measure select Healthy People 2010 Leading Health Indicators in young adults with and without a history of developmental disabilities (DD) using a population-based cohort. Methods: Young adults were interviewed to assess the prevalence of seven Leading Health Indicators: physical activity, overweight and obesity, tobacco use, substance…

  17. Images of the Young Child in History: Enlightenment and Romance.

    Science.gov (United States)

    Kennedy, David

    1988-01-01

    From the ancient mythological motif of the divine child to the perspectives of Freud and Piaget, this historical inquiry traces the philosophical images of the young child in Western thought. (Author/BB)

  18. Life history and bioeconomy of the house mouse.

    Science.gov (United States)

    Berry, R J; Bronson, F H

    1992-11-01

    1. More is known about the western European house mouse, Mus (musculus) domesticus than any other non-human mammal. If laboratory and field information is combined, an extremely valuable understanding of the species' bioeconomy could be obtained. 2. The seven stages of mouse life-history are surveyed (up to birth, nest life, sex life, social structure, population statics and stability, senescence, and death), and the interactions between the changing phenotype and the environment are described. 3. These interactions can be used to build up a model of the opportunities and compromises which result in the fitness of individual mice. It is not yet possible to quantify such a model, but this should in principle be achievable.

  19. Understanding life together: A brief history of collaboration in biology

    Science.gov (United States)

    Vermeulen, Niki; Parker, John N.; Penders, Bart

    2013-01-01

    The history of science shows a shift from single-investigator ‘little science’ to increasingly large, expensive, multinational, interdisciplinary and interdependent ‘big science’. In physics and allied fields this shift has been well documented, but the rise of collaboration in the life sciences and its effect on scientific work and knowledge has received little attention. Research in biology exhibits different historical trajectories and organisation of collaboration in field and laboratory – differences still visible in contemporary collaborations such as the Census of Marine Life and the Human Genome Project. We employ these case studies as strategic exemplars, supplemented with existing research on collaboration in biology, to expose the different motives, organisational forms and social dynamics underpinning contemporary large-scale collaborations in biology and their relations to historical patterns of collaboration in the life sciences. We find the interaction between research subject, research approach as well as research organisation influencing collaboration patterns and the work of scientists. PMID:23578694

  20. The Surprising History of Claims for Life on the Sun

    Science.gov (United States)

    Crowe, Michael J.

    2011-11-01

    Because astronomers are now convinced that it is impossible for life, especially intelligent life, to exist on the Sun and stars, it might be assumed that astronomers have always held this view. This paper shows that throughout most of the history of astronomy, some intellectuals, including a number of well-known astronomers, have advocated the existence of intelligent life on our Sun and thereby on stars. Among the more prominent figures discussed are Nicolas of Cusa, Giordano Bruno, William Whiston, Johann Bode, Roger Boscovich, William Herschel, Auguste Comte, Carl Gauss, Thomas Dick, John Herschel, and François Arago. One point in preparing this paper is to show differences between the astronomy of the past and that of the present.

  1. Life-History Traits and Population Structure of Pederson Cleaner Shrimps Ancylomenes pedersoni.

    Science.gov (United States)

    Gilpin, Jessica A; Chadwick, Nanette E

    2017-12-01

    Cleaner organisms perform key functional roles in reducing rates of parasitism in marine communities. Pederson cleaner shrimps Ancylomenes pedersoni are major cleaners of reef fishes in the tropical western Atlantic and form obligate symbioses with host sea anemones. Information about their life-history traits would contribute to understanding how symbiosis impacts life-history evolution in crustaceans, but little is known about patterns of growth and reproduction in this anemone shrimp. We quantified growth, sexual reproduction, senescence, and mortality in individuals of A. pedersoni under laboratory conditions and their abundance and population size structure on coral reefs in St. Thomas, U.S. Virgin Islands. Von Bertalanffy growth curves were fitted to the data to determine age-size relationships, and the Beverton-Holt model was used to estimate mortality rates and size at maximum yield. Individuals grew rapidly when young, then slowed their growth after reaching sexual maturity at ~6 months. Individuals were gonochoric, with males attaining significantly smaller body sizes and shorter life spans than did females. Prior to death at <2 years, members of both genders exhibited senescence during which they ceased reproducing, shrank (females only), and decreased their activity levels over ~1-4 weeks. Field populations were abundant and composed mostly of juveniles during both years examined. Populations appeared to be stable but highly dynamic in terms of individuals, reaching maximum yield at 4 months of age. We conclude that obligate symbiosis with large sea anemones and cleaner mutualism with reef fishes both contribute to explaining aspects of the life history of Pederson shrimps, especially their apparent mating system of pure-search polygynandry. This life-history information also provides a scientific basis for sustainable fishery management and aquaculture of this key coral reef organism.

  2. The Examination of Relationship between Life Rhythm and Parent's Consciousness among Young Children

    OpenAIRE

    Tanaka, Saori

    2008-01-01

    The social background of child care and rearing has changed rapidly today in Japan. Also young children's life rhythm has changed compared with before. These disorders of life rhythm cause big influence to young children's mind and body health. To improve young child's mind and body health, it is effective that parents improve the life rhythm at home. Therefore, the educational campaign to parents about young child's life rhythm was held. In this research, the relationship between improvement...

  3. Study of Subjective Life Quality in Young People with Disabilities

    Directory of Open Access Journals (Sweden)

    Kurtanova Yu.E.,

    2014-08-01

    Full Text Available We present a study of subjective life quality in young people with disabilities compared with their healthy peers. The study sample comprised 62 women aged 14 to 18 years. The experimental study group consisted of 30 students of grades VIII-XI of Secondary School of home-based learning № 1673 "Support". The control group included 32 student of grades VIII-XI of School № 1222 with in-depth study of the German language. The methods used were: Medical Outcomes Study 36 Item Short Form Health Survey (SF-36, M. Kuhn test "Who am I" (M. Kuhn, T. McPartland; modification by T.V. Rumjantseva, Method and diagnosis of health, activity and mood, projective technique "Picture of the actual self" and "Picture of the desired self" with questions. We formulated conclusions about the features of the subjective assessment of the quality of life in young people with disabilities compared with their healthy peers.

  4. The history of life and death: a 'spiritual' history from invisible matter to prolongation of life.

    Science.gov (United States)

    Gemelli, Benedino

    2012-01-01

    Over a long period of time, particularly from the nineteenth century on, Francis Bacon's philosophy has been interpreted as centred on the Novum organum and focused on the role that a well-organized method may play in securing a reliable knowledge of nature. In fact, if we examine Bacon's oeuvre as a whole, including some recent manuscript findings (De vijs mortis), we can safely argue that the issues addressed in the Novum organum represent only a part of Bacon's agenda, and not even the most important ones. By contrast, it is apparent that, from the very beginning of his investigations, he emphasized the central role of medicine, the need to establish new approaches in the study of the vital functions and the importance of promoting new discoveries in the medical field, not so much to find a cure for the many illnesses that plagued mankind as to prolong human life. In this sense, Historia vitae et mortis plays a central role in Bacon's programme to extend human knowledge and power, for, in his opinion, human beings could recover their lost ability to live a long and healthy life by embarking on careful investigations of nature. Far from being a purely descriptive or abstract exercise, Bacon's historia can therefore be seen as an operative tool to attain some of mankind's basic aims.

  5. Experimental reintroduction reveals novel life-history variation in Laysan Ducks (Anas laysanensis)

    Science.gov (United States)

    Walters, Jeffrey R.; Reynolds, Michelle H.

    2013-01-01

    Subfossil remains indicate that the Laysan Duck (Anas laysanensis) formerly occurred throughout the Hawaiian archipelago, but for more than 150 years it has been confined to a single, small atoll in the northwestern chain, Laysan Island. In 2004–2005, 42 ducks were reintroduced from Laysan to Midway Atoll, where they exhibited variation in life history never observed on Laysan. On Laysan, females have never been observed to breed successfully at age 1 year and few attempt it, whereas on Midway, females routinely raised young at study; n = 21 and 19, respectively) and triple brooding has never been observed. Other novel life history on Midway included early cessation of parental care to renest. Altered life history on Midway is likely related to better feeding conditions and low population density compared with Laysan. An especially intriguing possibility is that the phenotypic plasticity observed represents exposure of hidden reaction norms evolved when the species inhabited a range of environments, but several alternative explanations exist. Future reintroductions of this species may provide opportunities to test hypotheses about mechanisms underlying phenotypic plasticity.

  6. Biologic History and the Cardinal Rule of Life

    Science.gov (United States)

    Schopf, J. W.

    2004-12-01

    In broad perspective, the history of life is remarkably static -- once set, a system that has changed little over all of geological time. The basic chemistry of living systems (CHONSP, and the monomers and polymers they compose), the genetics and cellular structure of life, even the ecologic division of the biologic world into "eaters" (heterotrophs) and "eatees" (autotrophs), are innovations all dating from the Archean that have carried over to the present. Throughout Earth history, biology has followed the Cardinal Rule of Life -- avoid change, never evolve at all! Biology maintains the status quo, opportunistically responding only if conditions change. Life's credo might well be "if it ain't broken, don't fix it." Of course, biomolecules do get "broken," by mutations, but living systems have many biochemical repair mechanisms. Evolution is a result of small changes that slip through unfixed. We see the results of evolution in the fossil record only because of the vastness, the true enormity, of geological time. What events punctuated this static underpinning to produce the modern living world? Only three, each in its own way shaping the course of life's history. The earliest, photosynthesis, freed life from dependence on foodstuffs made by nonbiologic processes. The advent of the advanced form of this process, oxygenic ("green plant") photosynthesis -- also an Archean innovation -- pumped oxygen into the environment (markedly increasing energy yields), "rusted the Earth" (evidenced by banded iron-formations), and, by ˜2,300 Ma ago, led to establishment of an aerobic-anaerobic ecosystem like that today. Not surprisingly, given the Cardinal Rule of Life, the inventors of this innovation, microbial cyanobacteria, evolved little over billions of years. The second major innovation was sex. In the modern world, this reproductive process is exhibited only by nucleated (eukaryotic) cells, derived from non-sexual eukaryotic ancestors. Although eukaryotes date from ˜2

  7. Issues Using the Life History Calendar in Disability Research

    Science.gov (United States)

    Scott, Tiffany N.; Harrison, Tracie

    2011-01-01

    Background Overall, there is a dearth of research reporting mixed-method data collection procedures using the LHC within disability research. Objective This report provides practical knowledge on use of the life history calendar (LHC) from the perspective of a mixed-method life history study of mobility impairment situated within a qualitative paradigm. Methods In this paper the method related literature referring to the LHC was reviewed along with its epistemological underpinnings. Further, the uses of the LHC in disability research were illustrated using preliminary data from reports of disablement in Mexican American and Non-Hispanic White women with permanent mobility impairment. Results From our perspective, the LHC was most useful when approached from an interpretive paradigm when gathering data from women of varied ethnic and socioeconomic strata. While we found the LHC the most useful tool currently available for studying disablement over the life course, there were challenges associated with its use. The LHC required extensive interviewer training. In addition, large segments of time were needed for completion depending on the type of participant responses. Conclusions Researchers planning to conduct a disability study may find our experience using the LHC valuable for anticipating issues that may arise when the LHC is used in mixed-method research. PMID:22014674

  8. Using Behavior Sequence Analysis to Map Serial Killers' Life Histories.

    Science.gov (United States)

    Keatley, David A; Golightly, Hayley; Shephard, Rebecca; Yaksic, Enzo; Reid, Sasha

    2018-03-01

    The aim of the current research was to provide a novel method for mapping the developmental sequences of serial killers' life histories. An in-depth biographical account of serial killers' lives, from birth through to conviction, was gained and analyzed using Behavior Sequence Analysis. The analyses highlight similarities in behavioral events across the serial killers' lives, indicating not only which risk factors occur, but the temporal order of these factors. Results focused on early childhood environment, indicating the role of parental abuse; behaviors and events surrounding criminal histories of serial killers, showing that many had previous convictions and were known to police for other crimes; behaviors surrounding their murders, highlighting differences in victim choice and modus operandi; and, finally, trial pleas and convictions. The present research, therefore, provides a novel approach to synthesizing large volumes of data on criminals and presenting results in accessible, understandable outcomes.

  9. Functional Linkages for the Pace of Life, Life-history, and Environment in Birds

    OpenAIRE

    Williams, Joseph B.; Miller, Richard A.; Harper, James M.; Wiersma, Popko

    2010-01-01

    For vertebrates, body mass underlies much of the variation in metabolism, but among animals of the same body mass, metabolism varies six-fold. Understanding how natural selection can influence variation in metabolism remains a central focus of Physiological Ecologists. Life-history theory postulates that many physiological traits, such as metabolism, may be understood in terms of key maturational and reproductive characteristics over an organism’s life-span. Although it is widely acknowledged...

  10. Life history and the evolution of parental care.

    Science.gov (United States)

    Klug, Hope; Bonsall, Michael B

    2010-03-01

    Patterns of parental care are strikingly diverse in nature, and parental care is thought to have evolved repeatedly multiple times. Surprisingly, relatively little is known about the most general conditions that lead to the origin of parental care. Here, we use a theoretical approach to explore the basic life-history conditions (i.e., stage-specific mortality and maturation rates, reproductive rates) that are most likely to favor the evolution of some form of parental care from a state of no care. We focus on parental care of eggs and eggs and juveniles and consider varying magnitudes of the benefits of care. Our results suggest that parental care can evolve under a range of life-history conditions, but in general will be most strongly favored when egg death rate in the absence of care is high, juvenile survival in the absence of care is low (for the scenario in which care extends into the juvenile stage), adult death rate is relatively high, egg maturation rate is low, and the duration of the juvenile stage is relatively short. Additionally, parental care has the potential to be favored at a broad range of adult reproductive rates. The relative importance of these life-history conditions in favoring or limiting the evolution of care depends on the magnitude of the benefits of care, the relationship between initial egg allocation and subsequent offspring survival, and whether care extends into the juvenile stage. The results of our model provide a general set of predictions regarding when we would expect parental care to evolve from a state of no care, and in conjunction with other work on the topic, will enhance our understanding of the evolutionary dynamics of parental care and facilitate comparative analyses.

  11. "Ant" and "grasshopper" life-history strategies in Saccharomyces cerevisiae.

    Science.gov (United States)

    Spor, Aymé; Wang, Shaoxiao; Dillmann, Christine; de Vienne, Dominique; Sicard, Delphine

    2008-02-13

    From the evolutionary and ecological points of view, it is essential to distinguish between the genetic and environmental components of the variability of life-history traits and of their trade-offs. Among the factors affecting this variability, the resource uptake rate deserves particular attention, because it depends on both the environment and the genetic background of the individuals. In order to unravel the bases of the life-history strategies in yeast, we grew a collection of twelve strains of Saccharomyces cerevisiae from different industrial and geographical origins in three culture media differing for their glucose content. Using a population dynamics model to fit the change of population size over time, we estimated the intrinsic growth rate (r), the carrying capacity (K), the mean cell size and the glucose consumption rate per cell. The life-history traits, as well as the glucose consumption rate, displayed large genetic and plastic variability and genetic-by-environment interactions. Within each medium, growth rate and carrying capacity were not correlated, but a marked trade-off between these traits was observed over the media, with high K and low r in the glucose rich medium and low K and high r in the other media. The cell size was tightly negatively correlated to carrying capacity in all conditions. The resource consumption rate appeared to be a clear-cut determinant of both the carrying capacity and the cell size in all media, since it accounted for 37% to 84% of the variation of those traits. In a given medium, the strains that consume glucose at high rate have large cell size and low carrying capacity, while the strains that consume glucose at low rate have small cell size but high carrying capacity. These two contrasted behaviors may be metaphorically defined as "ant" and "grasshopper" strategies of resource utilization. Interestingly, a strain may be "ant" in one medium and "grasshopper" in another. These life-history strategies are discussed

  12. Theorizing Learning in Life History - a psycho-societal approach

    DEFF Research Database (Denmark)

    Olesen, Henning Salling

    2007-01-01

    to the understanding of knowledge, based on examples from the author's research into professional learning (general practitioners). The pivotal role of language use and language socialisation is explained in brief, developing a psychodynamic complement to a language game concept of language use.......  Taking it's point of departure in some critical remarks to some of the most important recent theorizing of learning, this article presents an alternative framework for theorizing learning as a subjective process in a social and societal context, based in life history research. Key concepts...

  13. "Ant" and "grasshopper" life-history strategies in Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Aymé Spor

    Full Text Available From the evolutionary and ecological points of view, it is essential to distinguish between the genetic and environmental components of the variability of life-history traits and of their trade-offs. Among the factors affecting this variability, the resource uptake rate deserves particular attention, because it depends on both the environment and the genetic background of the individuals. In order to unravel the bases of the life-history strategies in yeast, we grew a collection of twelve strains of Saccharomyces cerevisiae from different industrial and geographical origins in three culture media differing for their glucose content. Using a population dynamics model to fit the change of population size over time, we estimated the intrinsic growth rate (r, the carrying capacity (K, the mean cell size and the glucose consumption rate per cell. The life-history traits, as well as the glucose consumption rate, displayed large genetic and plastic variability and genetic-by-environment interactions. Within each medium, growth rate and carrying capacity were not correlated, but a marked trade-off between these traits was observed over the media, with high K and low r in the glucose rich medium and low K and high r in the other media. The cell size was tightly negatively correlated to carrying capacity in all conditions. The resource consumption rate appeared to be a clear-cut determinant of both the carrying capacity and the cell size in all media, since it accounted for 37% to 84% of the variation of those traits. In a given medium, the strains that consume glucose at high rate have large cell size and low carrying capacity, while the strains that consume glucose at low rate have small cell size but high carrying capacity. These two contrasted behaviors may be metaphorically defined as "ant" and "grasshopper" strategies of resource utilization. Interestingly, a strain may be "ant" in one medium and "grasshopper" in another. These life-history

  14. Phenotypic plasticity in fish life-history traits in two neotropical reservoirs : Petit-Saut Reservoir in French Guiana and Brokopondo Reservoir in Suriname

    OpenAIRE

    Merona de, Bernard; Mol, J.; Vigouroux, R.; Chaves, P. D.

    2009-01-01

    Fish species are known for their large phenotypic plasticity in life-history traits in relation to environmental characteristics. Plasticity allows species to increase their fitness in a given environment. Here we examined the life-history response of fish species after an abrupt change in their environment caused by the damming of rivers. Two reservoirs of different age, both situated on the Guiana Shield, were investigated: the young Petit-Saut Reservoir in French Guiana (14 years) and the ...

  15. Life history of the Harlequin ladybird, Harmonia axyridis; a global meta-analysis

    NARCIS (Netherlands)

    Raak-van den Berg, C.L.; Hemerik, A.; Werf, van der W.; Jong, de P.W.; Lenteren, van J.C.

    2017-01-01

    Data collected en used for a meta analysis on life history data of H. axyridis. And the resulting 20 best models for each life history characteristic. Published in the paper: Life history of the Harlequin ladybird, Harmonia axyridis; a global meta-analysis.

  16. Atom and life - History of a research issued from nuclear

    International Nuclear Information System (INIS)

    Griset, Pascal; Picard, Jean-Francois

    2015-01-01

    As many examples illustrate the commitment of the French CEA in biology (development of medical imagery technologies, of the first prion test for the detection of the Creutzfeldt-Jakob disease), this book proposes an insight into those specific researches in life sciences performed within this institution initially devoted to nuclear sciences. This history comprises researches performed in Fontenay aux Roses at the initiative of Frederic Joliot on basic physiological processes, the development of a scientific library in Saclay where physicists, chemists and biologists worked together, the building of a medical department within the Saclay hospital, research activities in Grenoble, the regrouping of biology laboratories, the increasingly important mission of the Life Sciences Directorate within the CEA in four domains (radiobiology and radio-pathology, protein engineering and structural biology, medical imagery and pharmacology, eco-physiology and vegetal ecosystems). This research field is now characterized by its international dimension

  17. Impaired Perinatal Growth and Longevity: A Life History Perspective

    Directory of Open Access Journals (Sweden)

    Deborah M. Sloboda

    2009-01-01

    Full Text Available Life history theory proposes that early-life cues induce highly integrated responses in traits associated with energy partitioning, maturation, reproduction, and aging such that the individual phenotype is adaptively more appropriate to the anticipated environment. Thus, maternal and/or neonatally derived nutritional or endocrine cues suggesting a threatening environment may favour early growth and reproduction over investment in tissue reserve and repair capacity. These may directly affect longevity, as well as prioritise insulin resistance and capacity for fat storage, thereby increasing susceptibility to metabolic dysfunction and obesity. These shifts in developmental trajectory are associated with long-term expression changes in specific genes, some of which may be underpinned by epigenetic processes. This normative process of developmental plasticity may prove to be maladaptive in human environments in transition towards low extrinsic mortality and energy-dense nutrition, leading to the development of an inappropriate phenotype with decreased potential for longevity and/or increased susceptibility to metabolic disease.

  18. Learning in Life History - psycho-societal interpretation of biographies

    DEFF Research Database (Denmark)

    Olesen, Henning Salling

    2008-01-01

    Taking its point of departure from some critical remarks about some of the most important recent theorizing of learning, this article presents an alternative framework for theorizing learning as a subjective process in a social and societal context, based on life history research. The key concepts...... of subjectivity and experience, derived from European critical theory, are briefly introduced with respect to their intellectual background. Based on examples from the author’s research into the professional learning, the article outlines the implications of these concepts in relation to an understanding...... of emotional aspects of learning in everyday life and to an understanding of knowledge. The pivotal role of language use and language socialisation is explained in brief, and a psychodynamic complement to a language game concept of language use is developed....

  19. Early-Life Characteristics, Psychiatric History, and Cognition Trajectories in Later Life

    Science.gov (United States)

    Brown, Maria Teresa

    2010-01-01

    Purpose of the Study: Although considerable attention has been paid to the relationship between later-life depression and cognitive function, the relationship between a history of psychiatric problems and cognitive function is not very well documented. Few studies of relationships between childhood health, childhood disadvantage, and cognitive…

  20. Young children’s perspectives researched from everyday life

    DEFF Research Database (Denmark)

    Juhl, Pernille

    -Holzkamp 1991]. This theoretical juxtaposition contributes by linking children’s experiences and emotional feelings to concrete social situations in everyday life. These theoretical discussions contribute to methodological considerations in relation to doing situated analysis of preverbal children’s first......The paper discusses methodological issues in relation to researching young (0-4 year) children’s first person’s perspectives. Drawing on a recent Danish study of children’s compound everyday life across day care contexts and family life, I argue that focusing on the children’s gazes and bodily...... expressions constitute a central knowledge source for learning about the children’s perspectives. The aim is to raise a theoretical discussion about how the concept ‘conduct of life’ is related to the concept ‘first person perspective’ by a third concept ‘subjective situation’ [befindlichkeit, Osterkamp...

  1. Movements of Blue Sharks (Prionace glauca) across Their Life History

    Science.gov (United States)

    Vandeperre, Frederic; Aires-da-Silva, Alexandre; Fontes, Jorge; Santos, Marco; Serrão Santos, Ricardo; Afonso, Pedro

    2014-01-01

    Spatial structuring and segregation by sex and size is considered to be an intrinsic attribute of shark populations. These spatial patterns remain poorly understood, particularly for oceanic species such as blue shark (Prionace glauca), despite its importance for the management and conservation of this highly migratory species. This study presents the results of a long-term electronic tagging experiment to investigate the migratory patterns of blue shark, to elucidate how these patterns change across its life history and to assess the existence of a nursery area in the central North Atlantic. Blue sharks belonging to different life stages (n = 34) were tracked for periods up to 952 days during which they moved extensively (up to an estimated 28.139 km), occupying large parts of the oceanic basin. Notwithstanding a large individual variability, there were pronounced differences in movements and space use across the species' life history. The study provides strong evidence for the existence of a discrete central North Atlantic nursery, where juveniles can reside for up to at least 2 years. In contrast with previously described nurseries of coastal and semi-pelagic sharks, this oceanic nursery is comparatively vast and open suggesting that shelter from predators is not its main function. Subsequently, male and female blue sharks spatially segregate. Females engage in seasonal latitudinal migrations until approaching maturity, when they undergo an ontogenic habitat shift towards tropical latitudes. In contrast, juvenile males generally expanded their range southward and apparently displayed a higher degree of behavioural polymorphism. These results provide important insights into the spatial ecology of pelagic sharks, with implications for the sustainable management of this heavily exploited shark, especially in the central North Atlantic where the presence of a nursery and the seasonal overlap and alternation of different life stages coincides with a high fishing

  2. Life Stress and Adjustment: Effects of Life Events Experienced by Young Adolescents and Their Parents.

    Science.gov (United States)

    Cohen, Lawrence H.; And Others

    1987-01-01

    Used a longitudinal design to test the effects of life events experienced by young adolescents and their parents. Criteria were the adolescents' depression, anxiety and self-esteem. Analysis showed a significant effect for the adolescents' controllable, but not uncontrollable, negative events. (Author/RWB)

  3. Life-history evolution and mitogenomic phylogeny of caecilian amphibians.

    Science.gov (United States)

    San Mauro, Diego; Gower, David J; Müller, Hendrik; Loader, Simon P; Zardoya, Rafael; Nussbaum, Ronald A; Wilkinson, Mark

    2014-04-01

    We analyze mitochondrial genomes to reconstruct a robust phylogenetic framework for caecilian amphibians and use this to investigate life-history evolution within the group. Our study comprises 45 caecilian mitochondrial genomes (19 of them newly reported), representing all families and 27 of 32 currently recognized genera, including some for which molecular data had never been reported. Support for all relationships in the inferred phylogenetic tree is high to maximal, and topology tests reject all investigated alternatives, indicating an exceptionally robust molecular phylogenetic framework of caecilian evolution consistent with current morphology-based supraspecific classification. We used the mitogenomic phylogenetic framework to infer ancestral character states and to assess correlation among three life-history traits (free-living larvae, viviparity, specialized pre-adult or vernal teeth), each of which occurs only in some caecilian species. Our results provide evidence that an ancestor of the Seychelles caecilians abandoned direct development and re-evolved a free-living larval stage. This study yields insights into the concurrent evolution of direct development and of vernal teeth in an ancestor of Teresomata that likely gave rise to skin-feeding (maternal dermatophagy) behavior and subsequently enabled evolution of viviparity, with skin feeding possibly a homologous precursor of oviduct feeding in viviparous caecilians. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Life history parameters of narwhals (Monodon monoceros) from Greenland

    DEFF Research Database (Denmark)

    Garde, Eva; Hansen, Steen H; Ditlevsen, Susanne

    2015-01-01

    Life history parameters for narwhals (Monodon monoceros) were estimated based on age estimates from aspartic acid racemization of eye lens nuclei. Eyes, reproductive organs, and measures of body lengths were collected from 282 narwhals in East and West Greenland in the years 1993, 2004, and 2007–...... projection matrix was parameterized with the data on age structure and fertility rates. The annual rate of increase of narwhals in East Greenland was estimated to be 3.8% while narwhals in West Greenland had a rate of increase at 2.6%. Key words:......Life history parameters for narwhals (Monodon monoceros) were estimated based on age estimates from aspartic acid racemization of eye lens nuclei. Eyes, reproductive organs, and measures of body lengths were collected from 282 narwhals in East and West Greenland in the years 1993, 2004, and 2007......–2010. Age estimates were based on the racemization of L-aspartic acid to D-aspartic acid in the nucleus of the eye lens. The ratio of D- and L-enantiomers was measured using high-performance liquid chromatography. The age equation used, 420.32X − 24.02·year where X is the D/L ratio, was determined from data...

  5. Life history, immunity, Peto's paradox and tumours in birds.

    Science.gov (United States)

    Møller, A P; Erritzøe, J; Soler, J J

    2017-05-01

    Cancer and tumours may evolve in response to life-history trade-offs between growth and duration of development on one hand, and between growth and maintenance of immune function on the other. Here, we tested whether (i) bird species with slow developmental rates for their body size experience low incidence of tumours because slow development allows for detection of rapid proliferation of cell lineages. We also test whether (ii) species with stronger immune response during development are more efficient at detecting tumour cells and hence suffer lower incidence of tumours. Finally, we tested Peto's paradox, that there is a positive relationship between tumour incidence and body mass. We used information on developmental rates and body mass from the literature and of tumour incidence (8468 birds) and size of the bursa of Fabricius for 7659 birds brought to a taxidermist in Denmark. We found evidence of the expected negative relationship between incidence of tumours and developmental rates and immunity after controlling for the positive association between tumour incidence and body size. These results suggest that evolution has modified the incidence of tumours in response to life history and that Peto's paradox may be explained by covariation between body mass, developmental rates and immunity. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

  6. [Evaluation of quality of life in school children with a history of early severe malnutrition].

    Science.gov (United States)

    De Grandis, E S; Armelini, P A; Cuestas, E

    2014-12-01

    Severe malnutrition in young children may lead to long-term complications, in particular learning and psychosocial disorders linked to health related quality of life (HRQOL). The aim of this study was to evaluate HRQOL in children whit a history of severe malnutrition before 2 years of life, expecting to find lower scores in these patients. A comparative study was performed on schoolchildren between 5 and 12 years with a history of early severe malnutrition, excluding those with chronic diseases. The Controls were healthy siblings of patients. The sample size was estimated as 26 subjects per group (Total=52). Sociodemographic variables were recorded and the HRQOL was assessed with PedsQL4.0. Chi square and Student t test were applied. Significance level: Psocial dimension: 88.80±3.05 vs 95.71±1.52 (P<.0001), and school dimension: 74.58±3.80 vs 85.00±3.51 (P<.0001). Patients with a history of early severe malnutrition, showed significantly lower HRQOL scores compared with controls. Copyright © 2013 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

  7. Population-specific life histories contribute to metapopulation viability

    Science.gov (United States)

    Halsey, Samniqueka J.; Bell, Timothy J.; McEachern, A. Kathryn; Pavlovic, Noel B.

    2016-01-01

    Restoration efforts can be improved by understanding how variations in life-history traits occur within populations of the same species living in different environments. This can be done by first understanding the demographic responses of natural occurring populations. Population viability analysis continues to be useful to species management and conservation with sensitivity analysis aiding in the understanding of population dynamics. In this study, using life-table response experiments and elasticity analyses, we investigated how population-specific life-history demographic responses contributed to the metapopulation viability of the Federally threatened Pitcher's thistle (Cirsium pitcheri). Specifically, we tested the following hypotheses: (1) Subpopulations occupying different environments within a metapopulation have independent demographic responses and (2) advancing succession results in a shift from a demographic response focused on growth and fecundity to one dominated by stasis. Our results showed that reintroductions had a positive contribution to the metapopulation growth rate as compared to native populations which had a negative contribution. We found no difference in succession on the contribution to metapopulation viability. In addition, we identified distinct population-specific contributions to metapopulation viability and were able to associate specific life-history demographic responses. For example, the positive impact of Miller High Dunes population on the metapopulation growth rate resulted from high growth contributions, whereas increased time of plant in stasis for the State Park Big Blowout population resulted in negative contributions. A greater understanding of how separate populations respond in their corresponding environment may ultimately lead to more effective management strategies aimed at reducing extinction risk. We propose the continued use of sensitivity analyses to evaluate population-specific demographic influences on

  8. The psychosexual histories of young women with bulimia.

    Science.gov (United States)

    Abraham, S F; Bendit, N; Mason, C; Mitchell, H; O'Connor, N; Ward, J; Young, S; Llewellyn-Jones, D

    1985-03-01

    While it is known that anorexia nervosa patients show a wide range of sexual knowledge, attitudes and practices, the psychosexual histories of bulimia patients have not been studied. In this paper the psychosexual histories of 20 bulimic patients and 20 matched control subjects are presented. Bulimic patients were more likely to experience orgasm with masturbation, were more likely to have experimented with anal intercourse, and were more likely to describe their libido as 'above average.' Control subjects were more likely to experience orgasm during sexual intercourse. Bulimic patients associated high body weights with unattractiveness, and tended to withdraw from social and sexual activity at high weights. In other aspects of their sexual behaviour, and in their attitudes to sexual matters, the two groups were similar.

  9. Work-Life Conflict among Young Academics: Antecedents and Gender Effects

    Science.gov (United States)

    Dorenkamp, Isabelle; Süß, Stefan

    2017-01-01

    Aligning work and private life is a significant challenge for young academics because of demanding working conditions (e.g. high workload, low job security). It is particularly strong for young female academics due to growing family responsibilities. Our study aims to identify the factors influencing the work-life conflict of young academics and…

  10. Life history dependent morphometric variation in stream-dwelling Atlantic salmon

    Science.gov (United States)

    Letcher, B.H.

    2003-01-01

    The time course of morphometric variation among life histories for stream-dwelling Atlantic salmon (Salmo salar L.) parr (age-0+ to age-2+) was analyzed. Possible life histories were combinations of parr maturity status in the autumn (mature or immature) and age at outmigration (smolt at age-2+ or later age). Actual life histories expressed with enough fish for analysis in the 1997 cohort were immature/age-2+ smolt, mature/age-2 +smolt, and mature/age-2+ non-smolt. Tagged fish were assigned to one of the three life histories and digital pictures from the field were analyzed using landmark-based geometric morphometrics. Results indicated that successful grouping of fish according to life history varied with fish age, but that fish could be grouped before the actual expression of the life histories. By March (age-1+), fish were successfully grouped using a descriptive discriminant function and successful assignment ranged from 84 to 97% for the remainder of stream residence. A jackknife of the discriminant function revealed an average life history prediction success of 67% from age-1+ summer to smolting. Low sample numbers for one of the life histories may have limited prediction success. A MANOVA on the shape descriptors (relative warps) also indicated significant differences in shape among life histories from age-1+ summer through to smolting. Across all samples, shape varied significantly with size. Within samples, shape did not vary significantly with size for samples from December (age-0+) to May (age-1+). During the age-1+ summer however, shape varied significantly with size, but the relationship between shape and size was not different among life histories. In the autumn (age-1+) and winter (age-2+), life history differences explained a significant portion of the change in shape with size. Life history dependent morphometric variation may be useful to indicate the timing of early expressions of life history variation and as a tool to explore temporal and

  11. Young children's family history of stuttering and their articulation, language and attentional abilities: An exploratory study.

    Science.gov (United States)

    Choi, Dahye; Conture, Edward G; Tumanova, Victoria; Clark, Chagit E; Walden, Tedra A; Jones, Robin M

    The purpose of this study was to determine whether young children who do (CWS) and do not stutter (CWNS) with a positive versus negative family history of stuttering differ in articulation, language and attentional abilities and family histories of articulation, language and attention related disorders. Participants were 25 young CWS and 50 young CWNS. All 75 participants' caregivers consistently reported a positive or negative family history of stuttering across three consecutive time points that were about 8 months apart for a total of approximately 16 months. Each participant's family history focused on the same, relatively limited number of generations (i.e., participants' parents & siblings). Children's family history of stuttering as well as articulation, language, and attention related disorders was obtained from one or two caregivers during an extensive interview. Children's speech and language abilities were measured using four standardized articulation and language tests and their attentional abilities were measured using caregiver reports of temperament. Findings indicated that (1) most caregivers (81.5% or 75 out 92) were consistent in their reporting of positive or negative history of stuttering; (2) CWNS with a positive family history of stuttering, compared to those with a negative family history of stuttering, were more likely to have reported a positive family history of attention deficit/hyperactivity disorder (ADHD), and (3) CWNS with a positive family history of stuttering had lower language scores than those with a negative family history of stuttering. However, there were no such significant differences in family histories of ADHD and language scores for CWS with a positive versus negative family history of stuttering. In addition, although 24% of CWS versus 12% of CWNS's caregivers reported a positive family history of stuttering, inferential analyses indicated no significant differences between CWS and CWNS in relative proportions of family

  12. Biodiversity, Life History, and Conservation of Northeastern Pacific Chondrichthyans.

    Science.gov (United States)

    Ebert, David A; Bigman, Jennifer S; Lawson, Julia M

    The sharks, batoids, and chimaeras, collectively the class Chondrichthyes, are one of the most successful groups of fishes, with over 1250 species globally. Recent taxonomic revisions have increased their diversity by about 20% over the past 17 years (2000-2016). The Northeast Pacific Ocean is one of the top 20 most diverse regions/countries on the globe with 77 chondrichthyan species, a number less than a quarter that of the most species-rich area (Australia) but that has increased by 10% since 2000 to include three new species (two skates and a chimaera). In this chapter we discuss the species richness of chondrichthyans occurring in the Northeast Pacific Ocean, characterize their life histories, briefly review several fisheries, and summarize the conservation status of those chondrichthyans occurring in the region. Detailed descriptions and evaluations of fisheries can be found in Chapter 7 of AMB Volume 78. © 2017 Elsevier Ltd. All rights reserved.

  13. Life history and ecology of Cambarus halli (Hobbs)

    Science.gov (United States)

    Dennard, S.; Peterson, J.T.; Hawthorne, E.S.

    2009-01-01

    The life history of Cambarus halli, a crayfish endemic to the Tallapoosa River Basin, GA, was studied at four sites within the Tallapoosa River. Two sites had allopatric populations of C. halli, and two sites had populations of C. halli sympatric with C. englishi. Three age classes existed across sites. For Cambarus halli, total number of pleopodal eggs was positively related to carapace length, but egg size was only weakly positively related to carapace length. Cambarus halli were smaller across age classes at sympatric sites, but had greater growth rates than at allopatric sites. Cambarus halli density estimates were lower at sympatric sites, while proportions of reproductively active age-1 and age-2 individuals were higher at allopatric sites (63% vs. 33%).

  14. Life history strategy and the HEXACO personality dimensions.

    Science.gov (United States)

    Manson, Joseph H

    2015-01-16

    Although several studies have linked Life History Strategy (LHS) variation with variation in the Five Factor Model personality dimensions, no published research has explored the relationship of LHS to the HEXACO personality dimensions. The theoretically expected relationship of the HEXACO Emotionality factor to LHS is unclear. The results of two studies (N = 641) demonstrated that LHS indicators form part of a factor along with HEXACO Extraversion, Agreeableness, Conscientiousness, and (marginally) Honesty-Humility. People higher on these dimensions pursue a slower LHS. Neither Openness nor Emotionality was associated with this factor. Holding LHS constant, social involvement with kin was consistently predicted by higher Emotionality and was not consistently predicted by any other HEXACO factor. These results support a view of Emotionality as part of an LHS-independent personality dimension that influences the provision and receipt of kin altruism.

  15. Life History Strategy and the HEXACO Personality Dimensions

    Directory of Open Access Journals (Sweden)

    Joseph H. Manson

    2015-01-01

    Full Text Available Although several studies have linked Life History Strategy (LHS variation with variation in the Five Factor Model personality dimensions, no published research has explored the relationship of LHS to the HEXACO personality dimensions. The theoretically expected relationship of the HEXACO Emotionality factor to LHS is unclear. The results of two studies (N = 641 demonstrated that LHS indicators form part of a factor along with HEXACO Extraversion, Agreeableness, Conscientiousness, and (marginally Honesty-Humility. People higher on these dimensions pursue a slower LHS. Neither Openness nor Emotionality was associated with this factor. Holding LHS constant, social involvement with kin was consistently predicted by higher Emotionality and was not consistently predicted by any other HEXACO factor. These results support a view of Emotionality as part of an LHS-independent personality dimension that influences the provision and receipt of kin altruism.

  16. Life satisfaction and happiness among young adults with schizophrenia.

    Science.gov (United States)

    Fervaha, Gagan; Agid, Ofer; Takeuchi, Hiroyoshi; Foussias, George; Remington, Gary

    2016-08-30

    People with schizophrenia often experience persistent symptoms and impairments in community functioning; however, despite this, many individuals with the illness report high levels of well-being. We explored the level of subjective well-being in a sample of relatively young outpatients with schizophrenia and matched healthy controls. Seventy-five outpatients with schizophrenia and 72 demographically matched healthy controls, aged 18-35 years, participated in the present study. Subjective well-being was defined as a combination of happiness and satisfaction with life, each of which were measured using validated instruments. Symptom severity, insight, and cognition were also evaluated. People with schizophrenia endorsed significantly lower levels of subjective well-being than healthy controls although, there was substantial overlap in scores, and many participants with schizophrenia endorsed a high level of well-being. Both depressive symptoms and motivational deficits demonstrated significant independent predictive value for determining level of well-being. At a group level, the mean level of happiness and life satisfaction was lower among people with schizophrenia than healthy comparison participants. However, despite this mean difference, there exists marked overlap in individual scores between those with and without schizophrenia, demonstrating that many young people with schizophrenia do, in fact, endorse high levels of subjective well-being. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  17. Life-history tradeoffs and reproductive cycles in Spotted Owls

    Science.gov (United States)

    Stoelting, Ricka E.; Gutierrez, R.J.; Kendall, William L.; Peery, M. Zachariah

    2015-01-01

    The study of tradeoffs among life-history traits has long been key to understanding the evolution of life-history strategies. However, more recently, evolutionary ecologists have realized that reproductive costs have the potential to influence population dynamics. Here, we tested for costs of reproduction in the California Spotted Owl (Strix occidentalis occidentalis), and assessed whether costs of reproduction in year t − 1 on reproduction in year t could be responsible for regionally synchronized biennial cycles in reproductive output. Logistic regression analysis and multistate mark–recapture models with state uncertainty revealed that breeding reduced the likelihood of reproducing in the subsequent year by 16% to 38%, but had no influence on subsequent survival. We also found that costs of reproduction in year t − 1 were correlated with climatic conditions in year t, with evidence of higher costs during the dry phase of the El Niño–Southern Oscillation. Using a simulation-based population model, we showed that strong reproductive costs had the potential to create biennial cycles in population-level reproductive output; however, estimated costs of reproduction appeared to be too small to explain patterns observed in Spotted Owls. In the absence of strong reproductive costs, we hypothesize that observed natural cycles in the reproductive output of Spotted Owls are related to as-yet-unmeasured, regionally concordant fluctuations in environmental conditions or prey resources. Despite theoretical evidence for demographic effects, our analyses illustrate that linking tradeoffs to actual changes in population processes will be challenging because of the potential confounding effects of individual and environmental variation.

  18. Eco-genetic modeling of contemporary life-history evolution.

    Science.gov (United States)

    Dunlop, Erin S; Heino, Mikko; Dieckmann, Ulf

    2009-10-01

    We present eco-genetic modeling as a flexible tool for exploring the course and rates of multi-trait life-history evolution in natural populations. We build on existing modeling approaches by combining features that facilitate studying the ecological and evolutionary dynamics of realistically structured populations. In particular, the joint consideration of age and size structure enables the analysis of phenotypically plastic populations with more than a single growth trajectory, and ecological feedback is readily included in the form of density dependence and frequency dependence. Stochasticity and life-history trade-offs can also be implemented. Critically, eco-genetic models permit the incorporation of salient genetic detail such as a population's genetic variances and covariances and the corresponding heritabilities, as well as the probabilistic inheritance and phenotypic expression of quantitative traits. These inclusions are crucial for predicting rates of evolutionary change on both contemporary and longer timescales. An eco-genetic model can be tightly coupled with empirical data and therefore may have considerable practical relevance, in terms of generating testable predictions and evaluating alternative management measures. To illustrate the utility of these models, we present as an example an eco-genetic model used to study harvest-induced evolution of multiple traits in Atlantic cod. The predictions of our model (most notably that harvesting induces a genetic reduction in age and size at maturation, an increase or decrease in growth capacity depending on the minimum-length limit, and an increase in reproductive investment) are corroborated by patterns observed in wild populations. The predicted genetic changes occur together with plastic changes that could phenotypically mask the former. Importantly, our analysis predicts that evolutionary changes show little signs of reversal following a harvest moratorium. This illustrates how predictions offered by

  19. Marine reserves: fish life history and ecological traits matter.

    Science.gov (United States)

    Claudet, J; Osenberg, C W; Domenici, P; Badalamenti, F; Milazzo, M; Falcón, J M; Bertocci, I; Benedetti-Cecchi, L; García-Charton, J A; Goñi, R; Borg, J A; Forcada, A; De Lucia, G A; Perez-Ruzafa, A; Afonso, P; Brito, A; Guala, I; Le Diréach, L; Sanchez-Jerez, P; Somerfield, P J; Planes, S

    2010-04-01

    Marine reserves are assumed to protect a wide range of species from deleterious effects stemming from exploitation. However, some species, due to their ecological characteristics, may not respond positively to protection. Very little is known about the effects of life history and ecological traits (e.g., mobility, growth, and habitat) on responses of fish species to marine reserves. Using 40 data sets from 12 European marine reserves, we show that there is significant variation in the response of different species of fish to protection and that this heterogeneity can be explained, in part, by differences in their traits. Densities of targeted size-classes of commercial species were greater in protected than unprotected areas. This effect of protection increased as the maximum body size of the targeted species increased, and it was greater for species that were not obligate schoolers. However, contrary to previous theoretical findings, even mobile species with wide home ranges benefited from protection: the effect of protection was at least as strong for mobile species as it was for sedentary ones. Noncommercial bycatch and unexploited species rarely responded to protection, and when they did (in the case of unexploited bentho-pelagic species), they exhibited the opposite response: their densities were lower inside reserves. The use of marine reserves for marine conservation and fisheries management implies that they should ensure protection for a wide range of species with different life-history and ecological traits. Our results suggest this is not the case, and instead that effects vary with economic value, body size, habitat, depth range, and schooling behavior.

  20. Relative tooth size at birth in primates: Life history correlates.

    Science.gov (United States)

    Smith, Timothy D; Muchlinski, Magdalena N; Bucher, Wade R; Vinyard, Christopher J; Bonar, Christopher J; Evans, Sian; Williams, Lawrence E; DeLeon, Valerie B

    2017-11-01

    Dental eruption schedules have been closely linked to life history variables. Here we examine a sample of 50 perinatal primates (28 species) to determine whether life history traits correlate with relative tooth size at birth. Newborn primates were studied using serial histological sectioning. Volumes of deciduous premolars (dp 2 -dp 4 ), replacement teeth (if any), and permanent molars (M 1-2/3 ) of the upper jaw were measured and residuals from cranial length were calculated with least squares regressions to obtain relative dental volumes (RDVs). Relative dental volumes of deciduous or permanent teeth have an unclear relationship with relative neonatal mass in all primates. Relative palatal length (RPL), used as a proxy for midfacial size, is significantly, positively correlated with larger deciduous and permanent postcanine teeth. However, when strepsirrhines alone are examined, larger RPL is correlated with smaller RDV of permanent teeth. In the full sample, RDVs of deciduous premolars are significantly negatively correlated with relative gestation length (RGL), but have no clear relationship with relative weaning age. RDVs of molars lack a clear relationship with RGL; later weaning is associated with larger molar RDV, although correlations are not significant. When strepsirrhines alone are analyzed, clearer trends are present: longer gestations or later weaning are associated with smaller deciduous and larger permanent postcanine teeth (only gestational length correlations are significant). Our results indicate a broad trend that primates with the shortest RGLs precociously develop deciduous teeth; in strepsirrhines, the opposite trend is seen for permanent molars. Anthropoids delay growth of permanent teeth, while strepsirrhines with short RGLs are growing replacement teeth concurrently. A comparison of neonatal volumes with existing information on extent of cusp mineralization indicates that growth of tooth germs and cusp mineralization may be selected for

  1. The History with Two Prehistories. On the design of the Moscow Palace of Young Pioneers

    Directory of Open Access Journals (Sweden)

    Felix Novikov

    2016-11-01

    Full Text Available The article refers to the history of design of the Moscow Palace of Young Pioneers architectural complex on Leninskie (now Vorobievy Gory viewed in the context of evolution of the national architecture. While speaking about how the project came into being and which way was chosen to find the architectural character, the author proves that the Palace was a pivotal point in the history of Russian architecture and became one of the symbols of Soviet Modernism.

  2. Gynecomastia in two young men with histories of prolonged use of anabolic androgenic steroids

    OpenAIRE

    Orlandi, M.A.; Venegoni, E.; Pagani, C.

    2010-01-01

    The aim of this report is to highlight the risk of anabolic androgenic steroid-induced gynecomastia in young men involved in nonagonistic sports and the role of ultrasonography in its diagnosis. The authors describe two cases of gynecomastia in nonprofessional weight lifters with histories of AAS use. In both cases, the diagnosis was based on patient history and clinical findings, but the sonographic examination confirmed the clinical suspicion and excluded the presence of other types of dise...

  3. Evolution, human-microbe interactions, and life history plasticity.

    Science.gov (United States)

    Rook, Graham; Bäckhed, Fredrik; Levin, Bruce R; McFall-Ngai, Margaret J; McLean, Angela R

    2017-07-29

    A bacterium was once a component of the ancestor of all eukaryotic cells, and much of the human genome originated in microorganisms. Today, all vertebrates harbour large communities of microorganisms (microbiota), particularly in the gut, and at least 20% of the small molecules in human blood are products of the microbiota. Changing human lifestyles and medical practices are disturbing the content and diversity of the microbiota, while simultaneously reducing our exposures to the so-called old infections and to organisms from the natural environment with which human beings co-evolved. Meanwhile, population growth is increasing the exposure of human beings to novel pathogens, particularly the crowd infections that were not part of our evolutionary history. Thus some microbes have co-evolved with human beings and play crucial roles in our physiology and metabolism, whereas others are entirely intrusive. Human metabolism is therefore a tug-of-war between managing beneficial microbes, excluding detrimental ones, and channelling as much energy as is available into other essential functions (eg, growth, maintenance, reproduction). This tug-of-war shapes the passage of each individual through life history decision nodes (eg, how fast to grow, when to mature, and how long to live). Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Quality of Life after Young Ischemic Stroke of Mild Severity Is Mainly Influenced by Psychological Factors

    NARCIS (Netherlands)

    Bruijn, M.A. de; Synhaeve, N.E.; Rijsbergen, M.W. van; Leeuw, F.E. de; Mark, R.E.; Jansen, B.P.; Kort, P.L. de

    2015-01-01

    BACKGROUND: Long-term prognosis in terms of quality of life (QoL) in young stroke patients is of importance because they usually have a long life expectancy and extensive daily life demands. We aimed at determining which medical and psychological factors influence the QoL in young stroke patients

  5. Quality of life after young ischemic stroke of mild severity is mainly influenced by psychological factors

    NARCIS (Netherlands)

    de Bruijn, M.; Synhaeve, N.A.; van Rijsbergen, Marielle; de Leeuw, F.-E.; Mark, Ruth; Jansen, B.; de Kort, P.L.

    2015-01-01

    Background Long-term prognosis in terms of quality of life (QoL) in young stroke patients is of importance because they usually have a long life expectancy and extensive daily life demands. We aimed at determining which medical and psychological factors influence the QoL in young stroke patients

  6. Multi-state models: metapopulation and life history analyses

    Directory of Open Access Journals (Sweden)

    Arnason, A. N.

    2004-06-01

    Full Text Available Multi–state models are designed to describe populations that move among a fixed set of categorical states. The obvious application is to population interchange among geographic locations such as breeding sites or feeding areas (e.g., Hestbeck et al., 1991; Blums et al., 2003; Cam et al., 2004 but they are increasingly used to address important questions of evolutionary biology and life history strategies (Nichols & Kendall, 1995. In these applications, the states include life history stages such as breeding states. The multi–state models, by permitting estimation of stage–specific survival and transition rates, can help assess trade–offs between life history mechanisms (e.g. Yoccoz et al., 2000. These trade–offs are also important in meta–population analyses where, for example, the pre–and post–breeding rates of transfer among sub–populations can be analysed in terms of target colony distance, density, and other covariates (e.g., Lebreton et al. 2003; Breton et al., in review. Further examples of the use of multi–state models in analysing dispersal and life–history trade–offs can be found in the session on Migration and Dispersal. In this session, we concentrate on applications that did not involve dispersal. These applications fall in two main categories: those that address life history questions using stage categories, and a more technical use of multi–state models to address problems arising from the violation of mark–recapture assumptions leading to the potential for seriously biased predictions or misleading insights from the models. Our plenary paper, by William Kendall (Kendall, 2004, gives an overview of the use of Multi–state Mark–Recapture (MSMR models to address two such violations. The first is the occurrence of unobservable states that can arise, for example, from temporary emigration or by incomplete sampling coverage of a target population. Such states can also occur for life history reasons, such

  7. Young entrepreneurship and family influence: the life history of a successful young girl El espíritu empresarial joven y la influencia de la familia: la historia de vida de una emprendedora de suceso Empreendedorismo jovem e a influência da família: a história de vida de uma empreendedora de sucesso

    Directory of Open Access Journals (Sweden)

    Rivanda Meira Teixeira

    2011-03-01

    Full Text Available Personal characteristics of entrepreneurs and factors that influence their choices, actions and behavior are important aspects for understanding conception of a business. Factors were analyzed that affected or determined the course of a girl who started her business very early at age of thirteen years. More specifically, we sought to examine family influence and identify main characteristics that contributed to the success of this young girl. This young entrepreneur has been chosen because of her unique experience, undertaking a venture at such an early age, in order to detect new insights into major influences for success of her business. The strategy of case study was used and her life story was used as a technique for data collection including an in-depth interview. Parental influence was found to be decisive in the creation and development of this business and some characteristics of entrepreneurs in other studies were easily identified in this girl such as determination, creativity, desire for independence, continuous learning and use of social networksLas características personales de los emprendedores y los factores que influyen en sus preferencias, acciones y comportamientos son temas relevantes para la comprensión del proceso de creación de negocios. El objetivo de este estudio es analizar los factores que influenciaron o determinaron la trayectoria de una joven que inició su actividad económica a los trece años de edad. Especialmente, se pretendió analizar la influencia de la familia en esa trayectoria e identificar las características más sobresalientes que contribuyeron para su suceso. Esa joven emprendedora fue escogida para este estudio de caso, pues su experiencia singular - de iniciar un emprendimiento con tan poca edad - permite explotar nuevos insights sobre las características más destacables que influenciaron el suceso de su gestión. Se utilizó la historia de su vida como técnica de colecta de datos, con la

  8. Viviparity and K-selected life history in a Mesozoic marine plesiosaur (Reptilia, Sauropterygia).

    Science.gov (United States)

    O'Keefe, F R; Chiappe, L M

    2011-08-12

    Viviparity is known in several clades of Mesozoic aquatic reptiles, but evidence for it is lacking in the Plesiosauria. Here, we report a Late Cretaceous plesiosaur fossil consisting of a fetus preserved within an adult of the same taxon. We interpret this occurrence as a gravid female and unborn young and hence as definitive evidence for plesiosaur viviparity. Quantitative analysis indicates that plesiosaurs gave birth to large, probably single progeny. The combination of viviparity, large offspring size, and small brood number differs markedly from the pattern seen in other marine reptiles but does resemble the K-selected strategy of all extant marine mammals and a few extant lizards. Plesiosaurs may have shared other life history traits with these clades, such as sociality and maternal care.

  9. How Metamorphosis Is Different in Plethodontids: Larval Life History Perspectives on Life-Cycle Evolution

    Science.gov (United States)

    Beachy, Christopher K.; Ryan, Travis J.; Bonett, Ronald M.

    2017-01-01

    Plethodontid salamanders exhibit biphasic, larval form paedomorphic, and direct developing life cycles. This diversity of developmental strategies exceeds that of any other family of terrestrial vertebrate. Here we compare patterns of larval development among the three divergent lineages of biphasic plethodontids and other salamanders. We discuss how patterns of life-cycle evolution and larval ecology might have produced a wide array of larval life histories. Compared with many other salamanders, most larval plethodontids have relatively slow growth rates and sometimes exceptionally long larval periods (up to 60 mo). Recent phylogenetic analyses of life-cycle evolution indicate that ancestral plethodontids were likely direct developers. If true, then biphasic and paedomorphic lineages might have been independently derived through different developmental mechanisms. Furthermore, biphasic plethodontids largely colonized stream habitats, which tend to have lower productivity than seasonally ephemeral ponds. Consistent with this, plethodontid larvae grow very slowly, and metamorphic timing does not appear to be strongly affected by growth history. On the basis of this, we speculate that feeding schedules and stress hormones might play a comparatively reduced role in governing the timing of metamorphosis of stream-dwelling salamanders, particularly plethodontids. PMID:29269959

  10. Social Confidence in Early Adulthood among Young People with and without a History of Language Impairment

    Science.gov (United States)

    Durkin, Kevin; Toseeb, Umar; Botting, Nicola; Pickles, Andrew; Conti-Ramsden, Gina

    2017-01-01

    Purpose: The purposes of this study were to test the predictions that lower self-esteem and higher shyness in individuals with a history of language impairment (LI) would continue from adolescence into early adulthood and that those with LI would have lower social self-efficacy in early adulthood. Method: Participants were young people with a…

  11. The importance of family history in young patients with endometrial cancer

    NARCIS (Netherlands)

    Berends, MJW; Kleibeuker, JH; de Vries, EGE; Mourits, MJE; Hollema, H; Pras, E; van der Zee, AGJ

    Endometrial cancer occurs primarily in postmenopausal women older than 60 years of age. Especially in young patients with endometrial cancer, a positive family history with respect to cancer and/or development of synchronous or metachronous tumors can be indicative of hereditary factors. One generic

  12. Civil Rights Continued: How History Positions Young People to Contemplate Sexuality (In)justice

    Science.gov (United States)

    Schmidt, Sandra J.

    2014-01-01

    Same-sex marriage is part of a global civil rights struggle for LGBQ rights. How this movement is framed, advanced, and critiqued across the globe can be linked to how young people in schools are prepared to deliberate social issues in the political sphere. This article examines national history books as cultural artifacts that present what is…

  13. The History and Evolution of Young and Distant Radio Sources

    Science.gov (United States)

    Collier, Jordan

    We study two classes of object to gain a better understanding of the evolution of Active Galactic Nuclei (AGN): Infrared-Faint Radio Sources (IFRSs) and Gigahertz Peaked Spectrum (GPS) / Compact Steep Spectrum (CSS) sources. IFRSs are a recently discovered rare class of object, which were found to be strong in the radio but undetectable in extremely sensitive infrared observations from the Spitzer Space Telescope, even in stacked images with sigma 3. Therefore, IFRSs may significantly increase the number of known high-redshift galaxies. However, their non-detections in the optical and infrared prevented confirmation of their nature. Previous studies of IFRSs focused on very sensitive observations of a few small regions of the sky, and the largest sample consisted of 55 IFRSs. However, we follow the strategy of combining radio data with IR and optical data for a large region of the sky. Using these data, we discover a population of >1300 brighter IFRSs which are, for the first time, reliably detected in the infrared and optical. We present the first spectroscopic redshifts of IFRSs and show that the brightest IFRSs are at z > 2. Furthermore, we rule out that IFRSs are Star Forming Galaxies, hotspots, lobes or misidentifications. We find the first X-ray counterparts of IFRSs, and increase the number of known polarised IFRSs five-fold. We present an analysis of their radio spectra and show that IFRSs consist of GPS, CSS and ultra-steep-spectrum sources. We follow up >50 of these using VLBI observations, and confirm the AGN status of IFRSs. GPS and CSS sources are compact radio sources with a convex radio spectrum. They are widely thought to represent young and evolving radio galaxies that have recently launched their jets. However, good evidence exists in individual cases that GPS and CSS sources are one of the following: 1) frustrated by interactions with dense gas and dust in their environment; 2) prematurely dying radio sources; 3) recurrent radio galaxies. Their

  14. Histoires de vie et Formation de Nouveaux Savoirs Vitaux (Life Histories and the Formation of New Life Knowledge).

    Science.gov (United States)

    Pineau, Gaston

    1994-01-01

    Describes the use of life histories as a means for making sense of personal events and their application to education. Distinguishes three models for the use of life histories in education: the biographical model, the autobiographical model, and the dialectical model. (22 citations) (MAB)

  15. Life history and ecology of the elusive European short-snouted seahorse Hippocampus hippocampus.

    Science.gov (United States)

    Curtis, J M R; Santos, S V; Nadeau, J L; Gunn, B; Bigney Wilner, K; Balasubramanian, H; Overington, S; Lesage, C-M; D'entremont, J; Wieckowski, K

    2017-12-01

    To improve the understanding of the life history and ecology of one of Europe's most elusive fishes, the short-snouted seahorse Hippocampus hippocampus, data from wild populations in a shallow coastal lagoon in southern Portugal were analysed. The data were collected from 17 tagged seahorses on a focal-study grid as well as from >350 seahorses encountered during underwater visual surveys and a fishery-independent study using beach seines. These populations of settled juveniles and adults had a mean population density of 0·009 m -2 . During the study period (2000-2004), reproduction peaked in July and August. Juveniles recruited to the lagoon at c. 66 mm standard length (L S ) and 0·5 years of age and established small home ranges (0·8 to 18·2 m 2 ). First reproduction was estimated at 100 mm and 1 year of age. Based on a fitted von Bertalanffy model, H. hippocampus grew quickly (growth coefficient K = 0·93) to a maximum theoretical size L ∞  = 150 mm and have a maximum lifespan of c. 3·2 years. Courtship behaviours were consistent with the maintenance of pair bonds and males brooded multiple batches of young per year. Estimated annual reproductive output averaged 871 young (±632). Together these analyses provide the first life-history parameters for this species and indicate that H. hippocampus bears characteristics of opportunist and intermediate strategists. Such populations are predicted to exhibit large fluctuations in abundance, making them vulnerable to extended periods of poor recruitment. © 2017 The Fisheries Society of the British Isles.

  16. Counterfactuals and history: Contingency and convergence in histories of science and life.

    Science.gov (United States)

    Hesketh, Ian

    2016-08-01

    This article examines a series of recent histories of science that have attempted to consider how science may have developed in slightly altered historical realities. These works have, moreover, been influenced by debates in evolutionary science about the opposing forces of contingency and convergence in regard to Stephen Jay Gould's notion of "replaying life's tape." The article argues that while the historians under analysis seem to embrace contingency in order to present their counterfactual narratives, for the sake of historical plausibility they are forced to accept a fairly weak role for contingency in shaping the development of science. It is therefore argued that Simon Conway Morris's theory of evolutionary convergence comes closer to describing the restrained counterfactual worlds imagined by these historians of science than does contingency. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. From metamorphosis to maturity in complex life cycles: equal performance of different juvenile life history pathways.

    Science.gov (United States)

    Schmidt, Benedikt R; Hödl, Walter; Schaub, Michael

    2012-03-01

    Performance in one stage of a complex life cycle may affect performance in the subsequent stage. Animals that start a new stage at a smaller size than conspecifics may either always remain smaller or they may be able to "catch up" through plasticity, usually elevated growth rates. We study how size at and date of metamorphosis affected subsequent performance in the terrestrial juvenile stage and lifetime fitness of spadefoot toads (Pelobates fuscus). We analyzed capture-recapture data of > 3000 individuals sampled during nine years with mark-recapture models to estimate first-year juvenile survival probabilities and age-specific first-time breeding probabilities of toads, followed by model selection to assess whether these probabilities were correlated with size at and date of metamorphosis. Males attained maturity after two years, whereas females reached maturity 2-4 years after metamorphosis. Age at maturity was weakly correlated with metamorphic traits. In both sexes, first-year juvenile survival depended positively on date of metamorphosis and, in males, also negatively on size at metamorphosis. In males, toads that metamorphosed early at a small size had the highest probability to reach maturity. However, because very few toadlets metamorphosed early, the vast majority of male metamorphs had a very similar probability to reach maturity. A matrix projection model constructed for females showed that different juvenile life history pathways resulted in similar lifetime fitness. We found that the effects of date of and size at metamorphosis on different juvenile traits cancelled each other out such that toads that were small or large at metamorphosis had equal performance. Because the costs and benefits of juvenile life history pathways may also depend on population fluctuations, ample phenotypic variation in life history traits may be maintained.

  18. Metabolic syndrome and parental history of cardiovascular disease in young adults in urban Ghana.

    Science.gov (United States)

    Yeboah, Kwame; Dodam, Kennedy Konlan; Affrim, Patrick Kormla; Adu-Gyamfi, Linda; Bado, Anormah Rashid; Owusu Mensah, Richard N A; Adjei, Afua Bontu; Gyan, Ben

    2017-08-03

    Metabolic syndrome (MetS) in young adults poses significant cardiovascular diseases (CVD) risk for later years. Parental history of CVDs is known to affect the prevalence of CVD risk in adulthood. In sub-Saharan Africa, the burden of MetS in young adults and its relationship with parental CVDs is largely unknown. We studied the gender-specific prevalence of MetS and its association with parental history of diabetes, hypertension and CVDs in young adults resident in urban Ghana. In a cross-sectional design, 364 young adults aged 20-30 years were randomly recruited from students of University of Ghana. A structured questionnaire was used to collect data on demography, lifestyle, medical and parental medical history. Anthropometric indices and blood pressures were measured. Fasting blood samples were collected to measure plasma levels of glucose, lipid profile, urea and creatinine. MetS was defined according to the Joint Scientific Statement criteria. The prevalence of MetS was 12.4%, higher in females than male participants (18.4% vs 5.7, p = 0.019). Female participants had higher levels of all the components of MetS than the male participants. Compared to participants with no history of parental CVDs, participants with parental CVDs had a higher proportion of abdominal obesity. A positive history of parental CVDs was associated with increase in odds of MetS [OR (95% CI): 1.23 (1.12-3.04), p = 0.037]. In our study population, there is relatively high prevalence of MetS; higher in females compared to male participants. Parental history of CVDs was associated with MetS.

  19. Lifestyle intervention and quality of life in young obese patients

    Directory of Open Access Journals (Sweden)

    Rusu Alexandra Mihaela

    2012-06-01

    Full Text Available The study is aiming to demonstrate the benefits of weight loss following an individualized interval exercise training programme and dietary recommendations on quality of life in young obese patients.Material and method: We conducted a 6 months prospective study on 28 young obese patients (mean age 21.3±2.1 years; mean weight 83,66±20,65. Patients were evaluated at baseline and after 6 months of intervention trough cardiopulmonary exercise testing (using Cortex Metalyzer 3B system, body composition, (InBody720, and quality of life assessment (SF36 questionnaire. Interval training consisted in 50 minutes sessions, 3 times per week, at intensive endurance training zone (in the range of anaerobic threshold, completed by 1 minute interval in the range between anaerobic threshold and respiratory compensation point, for every 5 minutes of training. IET was supervised and guided by physical therapist. For exercise intensity and caloric consumption monitoring we used Polar RS 800 heart rate monitors. Pedometers were also used in order to achieve 6000 steps/day , in those days in which they also participated in physical training, and 10000 in days without physical training.General dietary recommendations were given to the patients in order to improve their nutritional habits and reduce caloric consumption. Al subjects received a individula recommendations for increasing the daily physical activity level.Results: At the end of the study we observe significant decrease of weight from 83.66±20.65 kg at 81.58±19.85kg, and increase of VO2 max from 1.83 ±0.33 l/min to 1.93±0.33 l/min. Regarding life quality – Physical Component Summary increased from 47.88±6.92 to 51.32±6.22, (p=0.01 and Mental Component Summary increased from 47.97±7.28 to 53.42±6.28 (p=0.01.Conclusions: 6 months of weight loss programe based on general dietary recommendations and physical training can decres weight and significantly improve health related quality of life.

  20. Education and employment outcomes of young adults with a history of developmental language disorder

    Science.gov (United States)

    Durkin, Kevin; Toseeb, Umar; Botting, Nicola; Pickles, Andrew

    2017-01-01

    Abstract Background Developmental language disorder (DLD) presents a considerable barrier for young adults to engage in further education and training. Early studies with young adults with DLD revealed poor educational achievement and lack of opportunities to progress in education. More recent studies have provided more positive findings. Relatively sparse data exist, however, on current cohorts and the factors that predict outcomes. Aims To examine educational and employment outcomes in young adulthood in a sample of people with histories of DLD compared with an age‐matched peer group without DLD. We ask: How do educational pathways and early jobs compare between those with and without DLD? Are young adults with DLD receiving similar levels of income as their peers? To what extent are language and literacy abilities associated with outcomes? Methods & Procedures Participants included 84 individuals with DLD (67% males) and 88 age‐matched peers without DLD (56% males). Participants were on average 24 years of age. They completed a battery of psycholinguistic, literacy and nonverbal skills assessments. Data were also collected on educational qualifications, current educational status, extent of educational support received, employment status, history and support, as well as current income. Outcomes & Results Those with DLD obtained lower academic and vocational qualifications. Higher educational/vocational qualifications were associated with better language, better reading and higher performance IQ (PIQ). There were few differences between the two groups in terms of engagement with education, but the mean age at leaving education was significantly earlier in the participants with DLD. Substantially more participants with DLD reported receiving support or dispensation from their educational institution. There was no significant difference between groups in the proportion of young people currently employed, though a higher proportion of the age‐matched peers was

  1. Education and employment outcomes of young adults with a history of developmental language disorder.

    Science.gov (United States)

    Conti-Ramsden, Gina; Durkin, Kevin; Toseeb, Umar; Botting, Nicola; Pickles, Andrew

    2018-03-01

    Developmental language disorder (DLD) presents a considerable barrier for young adults to engage in further education and training. Early studies with young adults with DLD revealed poor educational achievement and lack of opportunities to progress in education. More recent studies have provided more positive findings. Relatively sparse data exist, however, on current cohorts and the factors that predict outcomes. To examine educational and employment outcomes in young adulthood in a sample of people with histories of DLD compared with an age-matched peer group without DLD. We ask: How do educational pathways and early jobs compare between those with and without DLD? Are young adults with DLD receiving similar levels of income as their peers? To what extent are language and literacy abilities associated with outcomes? Participants included 84 individuals with DLD (67% males) and 88 age-matched peers without DLD (56% males). Participants were on average 24 years of age. They completed a battery of psycholinguistic, literacy and nonverbal skills assessments. Data were also collected on educational qualifications, current educational status, extent of educational support received, employment status, history and support, as well as current income. Those with DLD obtained lower academic and vocational qualifications. Higher educational/vocational qualifications were associated with better language, better reading and higher performance IQ (PIQ). There were few differences between the two groups in terms of engagement with education, but the mean age at leaving education was significantly earlier in the participants with DLD. Substantially more participants with DLD reported receiving support or dispensation from their educational institution. There was no significant difference between groups in the proportion of young people currently employed, though a higher proportion of the age-matched peers was in work full time. Participants with DLD were much more likely to be

  2. The Dark Triad Traits from a Life History Perspective in Six Countries

    Directory of Open Access Journals (Sweden)

    Peter K. Jonason

    2017-08-01

    Full Text Available Work on the Dark Triad traits has benefited from the use of a life history framework but it has been limited to primarily Western samples and indirect assessments of life history strategies. Here, we examine how the Dark Triad traits (i.e., psychopathy, Machiavellianism, and narcissism relate to two measures of individual differences in life history strategies. In Study 1 (N = 937, we replicated prior observed links between life history strategies, as measured by the Mini-K, and the Dark Triad traits using samples recruited from three countries. In Study 2 (N = 1032, we measured life history strategies using the Consideration of Future Consequences Scale and correlated it with the Dark Triad traits in samples recruited from three additional countries. While there was some variability across participants’ sex and country, the results were generally consistent in that psychopathy and (to a lesser extent Machiavellianism were related to faster life history strategies and narcissism was related to slower life history strategies. These results add cross-cultural data and the use of two measures of life history speed to understand the Dark Triad traits from a life history perspective.

  3. Functional linkages for the pace of life, life-history, and environment in birds.

    Science.gov (United States)

    Williams, Joseph B; Miller, Richard A; Harper, James M; Wiersma, Popko

    2010-11-01

    For vertebrates, body mass underlies much of the variation in metabolism, but among animals of the same body mass, metabolism varies six-fold. Understanding how natural selection can influence variation in metabolism remains a central focus of Physiological Ecologists. Life-history theory postulates that many physiological traits, such as metabolism, may be understood in terms of key maturational and reproductive characteristics over an organism's life-span. Although it is widely acknowledged that physiological processes serve as a foundation for life-history trade-offs, the physiological mechanisms that underlie the diversification of life-histories remain elusive. Data show that tropical birds have a reduced basal metabolism (BMR), field metabolic rate, and peak metabolic rate compared with temperate counterparts, results consistent with the idea that a low mortality, and therefore increased longevity, and low productivity is associated with low mass-specific metabolic rate. Mass-adjusted BMR of tropical and temperate birds was associated with survival rate, in accordance with the view that animals with a slow pace of life tend to have increased life spans. To understand the mechanisms responsible for a reduced rate of metabolism in tropical birds compared with temperate species, we summarized an unpublished study, based on data from the literature, on organ masses for both groups. Tropical birds had smaller hearts, kidneys, livers, and pectoral muscles than did temperate species of the same body size, but they had a relatively larger skeletal mass. Direct measurements of organ masses for tropical and temperate birds showed that the heart, kidneys, and lungs were significantly smaller in tropical birds, although sample sizes were small. Also from an ongoing study, we summarized results to date on connections between whole-organism metabolism in tropical and temperate birds and attributes of their dermal fibroblasts grown in cell culture. Cells derived from

  4. Life history dictates fluorosis risk in a small mammal community

    International Nuclear Information System (INIS)

    Rafferty, D.P.; Faulkner, B.; Lochmiller, R.L.; Qualls, C.W. Jr.; McBee, K.

    1995-01-01

    Dental lesions, due to fluorosis, previously have been reported in wild, male cotton rats (Sigmodon hispidus) on an abandoned oil refinery located at the Oklahoma Refining Company in Cyril, Oklahoma. This study was expanded to include examinations of the fulvous harvest mouse (Reithrodontomys fulvescens), house mouse (Mus musculus), prairie vole (Microtus ochrogaster), plains pocket gopher (Geomys bursarius), least shrew (Cryptotis parva), shorttailed shrew (Blarina brevicauda), and deer mouse (Peromyscus spp.) at this same site. A sample of each species was collected form the contaminated refining site and a reference site with no known contamination. The authors grossly scored dentition of lower and upper incisors, microscopically examined cellular aberrations in ameloblasts and ondontoblasts, and quantified femur fluoride levels. Alterations in the lower and upper incisors were common in prairie voles, whose incisors possessed striations and erosion of the enamel and appeared chalky white. Incisors of animals taken from the reference site were normal. Patterns in occurrence of fluorosis and degree of enamel erosion was examined relative to the life history characteristics of the species

  5. Life History of the Emerald Jewel Wasp Ampulex compressa

    Directory of Open Access Journals (Sweden)

    Ryan Arvidson

    2018-04-01

    Full Text Available The Emerald Jewel Wasp Ampulex compressa (Fabricius is an endoparasitoid of the American cockroach Periplaneta americana (Linnaeus. Its host subjugation strategy is unusual in that envenomation is directed into the host central nervous system, eliciting a long-term behavior modification termed hypokinesia, turning stung cockroaches into a lethargic and compliant, but not paralyzed, living food supply for wasp offspring. A. compressa manipulates hypokinesic cockroaches into a burrow, where it oviposits a single egg onto a mesothoracic leg, hatching three days later. Herein we describe the life history and developmental timing of A. compressa. Using head capsule measurements and observations of mandibular morphology, we found that the larvae develop through three instars, the first two ectoparasitoid, and the third exclusively endoparasitoid. The first two instars have mandibles sufficient for piercing and cutting the cuticle respectively, while the third instar has a larger and blunter mandibular structure. During ecdysis to the third instar, the larva enters the body cavity of the cockroach, consuming internal tissues selectively, including fat body and skeletal muscle, but sparing the gut and Malpighian tubules. The developmental timing to pupation is similar between males and females, but cocoon volume and mass, and pupation duration are sexually dimorphic. Further, we show that the difference in cocoon mass and volume can be used to predict sex before eclosion, which is valuable for studies in venom pharmacology, as only females produce venom.

  6. A Course on Humanistic Creativity in Later Life: Literature Review, Case Histories, and Recommendations.

    Science.gov (United States)

    Nuessel, Frank; Van Stewart, Arthur; Cedeno, Aristofanes

    2001-01-01

    Presents case histories of late-life creativity in literature (May Sarton), painting (Marcel Duchamp), music (Leos Janacek), dance (Martha Graham), and theatre (Jessica Tandy). Offers suggestions for a course on humanistic creativity in later life. (Contains 74 references.) (SK)

  7. Migration of steelhead - Genetic basis of migratory tendency and life history plasticity in Oncorhynchus mykiss

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Steelhead and rainbow trout are the same species. However, their life histories diverge - with steelhead undertaking an anadromous life cycle whereas rainbow trout...

  8. Environmental effects on growth, reproduction, and life-history traits of loggerhead turtles

    NARCIS (Netherlands)

    Marn, Nina; Jusup, Marko; Legović, Tarzan; Kooijman, S. A.L.M.; Klanjšček, Tin

    2017-01-01

    Understanding the relationship between the environmental conditions and life-history traits (such as growth, reproduction, and size at specific life stages) is important for understanding the population dynamics of a species and for constructing adaptable, relevant, and efficient conservation

  9. Life history theory and breast cancer risk: methodological and theoretical challenges: Response to "Is estrogen receptor negative breast cancer risk associated with a fast life history strategy?".

    Science.gov (United States)

    Aktipis, Athena

    2016-01-01

    In a meta-analysis published by myself and co-authors, we report differences in the life history risk factors for estrogen receptor negative (ER-) and estrogen receptor positive (ER+) breast cancers. Our meta-analysis did not find the association of ER- breast cancer risk with fast life history characteristics that Hidaka and Boddy suggest in their response to our article. There are a number of possible explanations for the differences between their conclusions and the conclusions we drew from our meta-analysis, including limitations of our meta-analysis and methodological challenges in measuring and categorizing estrogen receptor status. These challenges, along with the association of ER+ breast cancer with slow life history characteristics, may make it challenging to find a clear signal of ER- breast cancer with fast life history characteristics, even if that relationship does exist. The contradictory results regarding breast cancer risk and life history characteristics illustrate a more general challenge in evolutionary medicine: often different sub-theories in evolutionary biology make contradictory predictions about disease risk. In this case, life history models predict that breast cancer risk should increase with faster life history characteristics, while the evolutionary mismatch hypothesis predicts that breast cancer risk should increase with delayed reproduction. Whether life history tradeoffs contribute to ER- breast cancer is still an open question, but current models and several lines of evidence suggest that it is a possibility. © The Author(s) 2016. Published by Oxford University Press on behalf of the Foundation for Evolution, Medicine, and Public Health.

  10. Dysmenorrhea: Prevalence and Impact on Quality of Life among Young Adult Jordanian Females.

    Science.gov (United States)

    Al-Jefout, Moamar; Seham, Abu-Fraijeh; Jameel, Hijazeen; Randa, Al-Qaisi; Ola, Al-Ma'aitah; Oday, Al-Ma'aitah; Luscombe, Georgina

    2015-06-01

    To establish the prevalence and impact on quality of life of dysmenorrhea among young adult Jordanian females. Cross-sectional study based on quantitative self-reported anonymous questionnaire. University-based study. A total of 272 female medical students (aged 19-25 years). None. Self-reports of menstruation-related pain symptoms and methods of dealing with them. Of study subjects 152/272 (55.8%) participants had moderate and severe dysmenorrhea. Of them, 55.8% had a family history of severe dysmenorrhea compared with 33.1% of those without dysmenorrhea (χ2 = 13.40, df = 1, P dysmenorrhea and poor university attendance (χ(2) = 45.35, df = 2, P Dysmenorrhea worsens during examination periods in 50% of cases. The most common pain symptom was low back pain (60.2%). Body mass index, family monthly income and early age at menarche had no correlation with the occurrence of dysmenorrhea. Of those with dysmenorrhea, 69.4% were using analgesics. Mothers were the main source of information regarding menstruation. Dysmenorrhea is highly prevalent among young adult Jordanian females and seems to negatively affect quality of life, particularly as related to university attendance and performance and social relationships. Copyright © 2015 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

  11. Life history and population dynamics of an estuarine amphipod, Eriopisa chilkensis Chilton (Gammaridae)

    Digital Repository Service at National Institute of Oceanography (India)

    Aravind, N.P.; Sheeba, P.; Nair, K.K.C.; Achuthankutty, C.T.

    Life history and Population Dynamics of an Estuarine Amphipod –Eriopisa chilkensis Chilton (Gammaridae) Nisha. P. Aravind, P. Sheeba, K.K.C. Nair and C.T.Achuthankutty* National Institute of Oceanography, Regional Centre, Cochin 682018, India... of laboratory data to the field suggests that E. chilkensis in Cochin estuary has a multivoltine life cycle. Key words: - Eriopisa chilkensis, Amphipoda, life cycle, population dynamics, Cochin estuary, India 2 1. Introduction Life-history traits of 214 amphipod...

  12. Quality of life, self-esteem and worries in young adult survivors of childhood cancer.

    Science.gov (United States)

    Langeveld, N E; Grootenhuis, M A; Voûte, P A; de Haan, R J; van den Bos, C

    2004-12-01

    This study assessed quality of life, self-esteem and worries in young adult survivors of childhood cancer compared to a group of young adults with no history of cancer. The impact of demographic, medical and treatment factors and self-esteem on survivors' quality of life and worries was studied. Participants were 400 long-term survivors (LTS) of childhood cancer (age range 16-49 years, 45% female) who had completed treatment an average of 16 years previously and 560 persons (age range 16-53 years, 55% female) with no history of cancer. All participants completed the MOS-24 (Medical Outcome Study Scale), a Worry questionnaire consisting of three scales (cancer-specific concerns, general health concerns, present and future concerns), and the Rosenberg Self-Esteem Scale. Small to moderate differences were found in mean MOS-24 scores between the LTS group and controls (range effect sizes -0.36-0.22). No significant difference was found in the mean self-esteem scores between LTS and controls. Female LTS had more cancer-specific concerns than male LTS. In several related areas of general health, self-image and dying, the LTS group reported less worries than controls, but LTS worried significantly more about their fertility, getting/changing a job and obtaining insurance's. Multiple linear regression analysis revealed that female gender, unemployment, severe late effects/health problems and a low self-esteem were predictors of worse quality of life in survivors. In addition, age at follow-up, unemployment, years since completion of therapy and a low self-esteem were associated with a higher degree of survivors' worries. Quality of life and the level of self-esteem in LTS of childhood cancer is not different from their peers. Although many LTS worried not more or even less about health issues than their peers, they often are concerned about some present and future concerns. The investigated factors could explain poor quality of life and worries only to a limited extent

  13. The Life Journeys Of Young Women Project: objectives, design, and recruitment results.

    Science.gov (United States)

    Steele, Emily J; Giles, Lynne C; Davies, Michael J; Moore, Vivienne M

    2011-07-01

    The Life Journeys of Young Women Project is the first population-based study to examine the role of economic uncertainty throughout early adulthood on age at first childbirth. A retrospective cross-sectional component was added to an existing cohort study that is based on a birth cohort of women born during 1973-1975 in Adelaide, South Australia (n ∼ 1,000). An event history calendar instrument was used to obtain data regarding a range of life domains including partnering, educational attainment, home ownership, higher education debt, employment, and pregnancies over a 20-year period (sometimes as detailed as at monthly intervals). Interviews were conducted between 2007 and 2009. An analysis framework applying time-varying and time-constant survival analysis techniques within a life-course framework was developed that will guide analyses to examine the role of duration and life-course timing of economic uncertainty on age at first childbirth. This paper discusses study objectives and design, fieldwork procedures, planned statistical analyses, and recruitment outcomes, focusing on novel features that would facilitate analogous epidemiologic research.

  14. Everyday Life of Young Adults with Intellectual Disabilities: Inclusionary and Exclusionary Processes among Young Adults of Parents with Intellectual Disability

    Science.gov (United States)

    Starke, Mikaela

    2013-01-01

    Ten young adults with an intellectual disability whose parents, too, have an intellectual disability were interviewed and completed questionnaires for this exploratory study aimed at charting their experiences of everyday life. Most of the participants reported high life satisfaction, especially with the domains of friends, leisure time, and…

  15. Talking (or not) about family health history in families of Latino young adults.

    Science.gov (United States)

    Corona, Rosalie; Rodríguez, Vivian; Quillin, John; Gyure, Maria; Bodurtha, Joann

    2013-10-01

    Although individuals recognize the importance of knowing their family's health history for their own health, relatively few people (e.g., less than a third in one national survey) collect this type of information. This study examines the rates of family communication about family health history of cancer, and predictors of communication in a sample of English-speaking Latino young adults. A total of 224 Latino young adults completed a survey that included measures on family communication, cultural factors, religious commitment, and cancer worry. We found that few Latino young adults reported collecting information from their families for the purposes of creating a family health history (18%) or sharing information about hereditary cancer risk with family members (16%). In contrast, slightly more than half of the participants reported generally "talking with their mothers about their family's health history of cancer." Logistic regression results indicated that cancer worry (odds ratio [OR] = 2.31; 95% confidence interval [CI] = 1.08-4.93), being female (OR = 3.12; 95% CI = 1.02-8.08), and being older (OR = 1.33; 95% CI = 1.01-1.76) were associated with increased rates of collecting information from family members. In contrast, orientation to the Latino culture (OR = 2.81; 95% CI = 1.33-5.94) and religious commitment (OR = 1.54; 95% CI = 1.02-2.32) were associated with increased rates of giving cancer information. Results highlight the need for prevention programs to help further general discussions about a family's history of cancer to more specific information related to family health history.

  16. Later Life Parental Divorce and Widowhood: Impact on Young Adults' Assessment of Parent-Child Relations.

    Science.gov (United States)

    Aquilino, William S.

    1994-01-01

    Explored implications of later life parental divorce and widowhood for relationship between parents and young adult children among 3,281 young adults who grew up in intact families. Family disruption that occurred after children were grown had sizable effects on parent-adult child relations, with later life divorce lowering relationship quality…

  17. Life Transitions and Mental Health in a National Cohort of Young Australian Women

    Science.gov (United States)

    Lee, Christiana; Gramotnev, Helen

    2007-01-01

    Young adulthood, a time of major life transitions and risk of poor mental health, may affect emotional well-being throughout adult life. This article uses longitudinal survey data to examine young Australian women's transitions across 4 domains: residential independence, relationships, work and study, and motherhood. Changes over 3 years in…

  18. Unfinalisability and the authorship of life - Narratives of young-old women from Taiwan.

    Science.gov (United States)

    Kok, Jin Kuan; Li, Ming-Chin

    2017-08-01

    This study investigates and presents the narratives of Taiwanese women who have reached the young-old stage. The narrative interview method was used for data collection from 12 Taiwanese women. After analysing the recurring themes emerging from the women's life histories, it is found that the meanings of these Taiwanese women's narratives could not be finalised according to traditional Confucian norms. These women rebelled, resisted, and resumed authorship to make changes to their lives in a patriarchal society. The women were reflexive, and had constant struggles. The findings also reveal a prominent characteristic of Taiwanese culture that emphasises relationships. The women were able to pursue their dreams to involve themselves in self-care, leisure, aesthetic activities, and classes for their personal growth and pleasure. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Integration of manatee life-history data and population modeling

    Science.gov (United States)

    Eberhardt, L.L.; O'Shea, Thomas J.; O'Shea, Thomas J.; Ackerman, B.B.; Percival, H. Franklin

    1995-01-01

    Aerial counts and the number of deaths have been a major focus of attention in attempts to understand the population status of the Florida manatee (Trichechus manatus latirostris). Uncertainties associated with these data have made interpretation difficult. However, knowledge of manatee life-history attributes increased and now permits the development of a population model. We describe a provisional model based on the classical approach of Lotka. Parameters in the model are based on data from'other papers in this volume and draw primarily on observations from the Crystal River, Blue Spring, and Adantic Coast areas. The model estimates X (the finite rate ofincrease) at each study area, and application ofthe delta method provides estimates of variance components and partial derivatives ofX with respectto key input parameters (reproduction, adult survival, and early survival). In some study areas, only approximations of some parameters are available. Estimates of X and coefficients of variation (in parentheses) of manatees were 1.07 (0.009) in the Crystal River, 1.06 (0.012) at Blue Spring, and 1.01 (0.012) on the Atlantic Coast. Changing adult survival has a major effect on X. Early-age survival has the smallest effect. Bootstrap comparisons of population growth estimates from trend counts in the Crystal River and at Blue Spring and the reproduction and survival data suggest that the higher, observed rates from counts are probably not due to chance. Bootstrapping for variance estimates based on reproduction and survival data from manatees at Blue Spring and in the Crystal River provided estimates of X, adult survival, and rates of reproduction that were similar to those obtained by other methods. Our estimates are preliminary and suggestimprovements for future data collection and analysis. However, results support efforts to reduce mortality as the most effective means to promote the increased growth necessary for the eventual recovery of the Florida manatee

  20. Love Styles in the Context of Life History Theory

    Directory of Open Access Journals (Sweden)

    Marzec Magdalena

    2017-06-01

    Full Text Available The evolutionary function of love is to create a strong bond between the partners with reproduction in view. In order to achieve this goal, humans use various sexual/reproductive strategies, which have evolved due to specific reproductive benefits. The use of particular strategies depends on many factors but one of the most important is early childhood experiences, on which life history theory (LHT focuses. John Lee (1973 identified 6 basic love styles: eros, ludus, storge, pragma, agape, and mania. Our goal was to check whether love styles may be treated as sexual/reproductive strategies in the context of LHT - slow or fast strategy. In our study (N = 177 we found that people who prefer the slow reproductive strategy are inclined to show passionate, pragmatic and friendly love, and those who prefer the fast strategy, treated love as a game. A low level of environmental stress in childhood results in preferring eros, storge and agape love styles, belonging to the slow strategy, and a high one results in preferring ludus, which belongs to the fast strategy. People representing eros, storge or pragma styles have restricted sociosexual orientation so they prefer long-term relationships, whereas those with the ludus style are people with unrestricted orientation, preferring short-term relationships. Besides, storge, agape and pragma seem to determine preferring qualities connected with parental effort in one’s partner, mania - with mating effort, and eros - with both kinds of effort. No correlation was found between the love style and the number of children.

  1. Health-related Quality of Life in Young Adult Girls with Dysmenorrhea among University Medical Students in Shah Alam, Malaysia: A Cross-sectional Study

    Directory of Open Access Journals (Sweden)

    Kumeshini Sukalingam

    2016-10-01

    Full Text Available Dysmenorrhea is a notably serious crisis among young adult girls and it distresses their quality of life. After menarche, most young adult girls suffer severe pain, irregular menses, too much bleeding, and dysmenorrhea. It is a common gynecological complication affecting more than half of the young adult girls resulting in episodic school absenteeism coupled with a negative impact on social behavior, educational, and sports activities. This study was a cross-sectional descriptive, conducted from September to November 2013 among 210 young adult, female medical students of Management and Science University, using a semi-structured questionnaire. The questionnaire used in this study was associated with the health-related quality of life among young adult girls; questions were related to demography, family menstrual history, prevalence, symptoms, absentees of school, involvement in sports activities, and self-care strategies. This survey was completed and the data was analyzed for the results with percentages and chi-square test applied.

  2. Hormonal correlates of male life history stages in wild white-faced capuchin monkeys (Cebus capucinus).

    Science.gov (United States)

    Jack, Katharine M; Schoof, Valérie A M; Sheller, Claire R; Rich, Catherine I; Klingelhofer, Peter P; Ziegler, Toni E; Fedigan, Linda

    2014-01-01

    Much attention has been paid to hormonal variation in relation to male dominance status and reproductive seasonality, but we know relatively little about how hormones vary across life history stages. Here we examine fecal testosterone (fT), dihydrotestosterone (fDHT), and glucocorticoid (fGC) profiles across male life history stages in wild white-faced capuchins (Cebus capucinus). Study subjects included 37 males residing in three habituated social groups in the Área de Conservacíon Guanacaste, Costa Rica. Male life history stages included infant (0 to Life history stage was a significant predictor of fT; levels were low throughout the infant and juvenile phases, doubled in subadult and subordinate adults, and were highest for alpha males. Life history stage was not a significant predictor of fDHT, fDHT:fT, or fGC levels. Puberty in white-faced capuchins appears to begin in earnest during the subadult male phase, indicated by the first significant rise in fT. Given their high fT levels and exaggerated secondary sexual characteristics, we argue that alpha adult males represent a distinctive life history stage not experienced by all male capuchins. This study is the first to physiologically validate observable male life history stages using patterns of hormone excretion in wild Neotropical primates, with evidence for a strong association between fT levels and life history stage. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Revolutionaries, wanderers, converts, and compliants: Life histories of extreme right activists

    NARCIS (Netherlands)

    Linden, A.; Klandermans, P.G.

    2007-01-01

    Life-history interviews were conducted with thirty-six extreme right activists in the Netherlands (1996-1998). Becoming an activist was a matter of continuity, of conversion, or of compliance. Continuity denotes life histories wherein movement membership and participation are a natural consequence

  4. Host responses in life-history traits and tolerance to virus infection in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Israel Pagán

    2008-08-01

    Full Text Available Knowing how hosts respond to parasite infection is paramount in understanding the effects of parasites on host populations and hence host-parasite co-evolution. Modification of life-history traits in response to parasitism has received less attention than other defence strategies. Life-history theory predicts that parasitised hosts will increase reproductive effort and accelerate reproduction. However, empirical analyses of these predictions are few and mostly limited to animal-parasite systems. We have analysed life-history trait responses in 18 accessions of Arabidopsis thaliana infected at two different developmental stages with three strains of Cucumber mosaic virus (CMV. Accessions were divided into two groups according to allometric relationships; these groups differed also in their tolerance to CMV infection. Life-history trait modification upon virus infection depended on the host genotype and the stage at infection. While all accessions delayed flowering, only the more tolerant allometric group modified resource allocation to increase the production of reproductive structures and progeny, and reduced the length of reproductive period. Our results are in agreement with modifications of life-history traits reported for parasitised animals and with predictions from life-history theory. Thus, we provide empirical support for the general validity of theoretical predictions. In addition, this experimental approach allowed us to quantitatively estimate the genetic determinism of life-history trait plasticity and to evaluate the role of life-history trait modification in defence against parasites, two largely unexplored issues.

  5. Life History Theory and Social Deviance: The Mediating Role of Executive Function

    Science.gov (United States)

    Wenner, C. J.; Bianchi, J.; Figueredo, A. J.; Rushton, J. Philippe; Jacobs, W. J.

    2013-01-01

    The present work examined predicted relations among Life History strategies, Executive Functions, socially antagonistic attitudes, socially antagonistic behaviors, and general intelligence. Life History (LH) theory predicts that Executive Functions and socially antagonistic attitudes and behaviors underpin an interrelated and coherent set of…

  6. Local adaptation in brown trout early life-history traits: implications for climate change adaptability

    DEFF Research Database (Denmark)

    Jensen, L.F.; Hansen, Michael Møller; Pertoldi, C.

    2008-01-01

    to adapt. Temperature-related adaptability in traits related to phenology and early life history are expected to be particularly important in salmonid fishes. We focused on the latter and investigated whether four populations of brown trout (Salmo trutta) are locally adapted in early life-history traits...

  7. A Life History of a Korean Adolescent Girl Who Attempted Suicide

    Science.gov (United States)

    Yang, Sungeun

    2012-01-01

    The present study explores the life history of a South Korean adolescent girl who attempted suicide. The study focuses on how sociocultural values affected her suicide attempt and how she made meaning out of the experience. The results revealed that her life history was a process of seeking independence and autonomy, and freeing herself from…

  8. Explaining density-dependent regulation in earthworm populations using life-history analysis

    NARCIS (Netherlands)

    Kammenga, J.E.; Spurgeon, D.J.; Svendsen, C.; Weeks, J.M.

    2003-01-01

    At present there is little knowledge about how density regulates population growth rate and to what extent this is determined by life-history patterns. We compared density dependent population consequences in the Nicholsonian sense based oil experimental observations and life-history modeling for

  9. Consilience and Life History Theory: From Genes to Brain to Reproductive Strategy

    Science.gov (United States)

    Figueredo, Aurelio Jose; Vasquez, Geneva; Brumbach, Barbara H.; Schneider, Stephanie M. R.; Sefcek, Jon A.; Tal, Ilanit R.; Hill, Dawn; Wenner, Christopher J.; Jacobs, W. Jake

    2006-01-01

    We describe an integrated theory of individual differences that traces the behavioral development of life history from genes to brain to reproductive strategy. We provide evidence that a single common factor, the K-Factor, underpins a variety of life-history parameters, including an assortment of sexual, reproductive, parental, familial, and…

  10. Mapping phenotypic plasticity and genotype-environment interactions affecting life-history traits in Caenorhabditis elegans

    NARCIS (Netherlands)

    Gutteling, E.W.; Riksen, J.A.G.; Bakker, J.; Kammenga, J.E.

    2007-01-01

    Phenotypic plasticity and genotype-environment interactions (GEI) play an important role in the evolution of life histories. Knowledge of the molecular genetic basis of plasticity and GEI provides insight into the underlying mechanisms of life-history changes in different environments. We used a

  11. The Treatment of Geological Time & the History of Life on Earth in High School Biology Textbooks

    Science.gov (United States)

    Summers, Gerald; Decker, Todd; Barrow, Lloyd

    2007-01-01

    In spite of the importance of geological time in evolutionary biology, misconceptions about historical events in the history of life on Earth are common. Glenn (1990) has documented a decline from 1960 to 1989 in the amount of space devoted to the history of life in high school earth science textbooks, but we are aware of no similar study in…

  12. Relationship between a history of consistent maternal employment and depression in young adults.

    Science.gov (United States)

    Chambliss, Catherine; Termine, Kim; Norton, Jenifer; Barry, Oliver; Bahm, Jonathan; Papas, Adam; Papas, Harris

    2010-12-01

    Research on the correlates of maternal employment has yielded inconsistent results. In this study, 79 male and 120 female undergraduates with mothers who had been employed from the students' infancy through their adolescence scored higher on the Beck Depression Inventory-II than those whose mothers had not been employed. This relationship between children's depressive symptoms and mothers' employment history was not evident among young adults whose mothers' employment was perceived to be financially unnecessary.

  13. Fast-slow continuum and reproductive strategies structure plant life-history variation worldwide

    DEFF Research Database (Denmark)

    Salguero-Gómez, Roberto; Jones, Owen R; Jongejans, Eelke

    2016-01-01

    The identification of patterns in life-history strategies across the tree of life is essential to our prediction of population persistence, extinction, and diversification. Plants exhibit a wide range of patterns of longevity, growth, and reproduction, but the general determinants of this enormous...... variation in life history are poorly understood. We use demographic data from 418 plant species in the wild, from annual herbs to supercentennial trees, to examine how growth form, habitat, and phylogenetic relationships structure plant life histories and to develop a framework to predict population...

  14. Prey nutrient composition has different effects on Pardosa wolf spiders with dissimilar life histories

    DEFF Research Database (Denmark)

    Jensen, Kim; Mayntz, David; Toft, Søren

    2011-01-01

    The nutritional composition of prey is known to influence predator life histories, but how the life history strategies of predators affect their susceptibility to nutrient imbalance is less investigated. We used two wolf spider species with different life histories as model predators: Pardosa...... amentata, which have a fixed annual life cycle, and Pardosa prativaga, which reproduce later and can extend development across 2 years. We fed juvenile spiders of the two species ad libitum diets of one of six Drosophila melanogaster fly types varying in lipid:protein composition during three instars, from...

  15. Ecological interactions in dinosaur communities: influences of small offspring and complex ontogenetic life histories.

    Directory of Open Access Journals (Sweden)

    Daryl Codron

    Full Text Available Because egg-laying meant that even the largest dinosaurs gave birth to very small offspring, they had to pass through multiple ontogenetic life stages to adulthood. Dinosaurs' successors as the dominant terrestrial vertebrate life form, the mammals, give birth to live young, and have much larger offspring and less complex ontogenetic histories. The larger number of juveniles in dinosaur as compared to mammal ecosystems represents both a greater diversity of food available to predators, and competitors for similar-sized individuals of sympatric species. Models of population abundances across different-sized species of dinosaurs and mammals, based on simulated ecological life tables, are employed to investigate how differences in predation and competition pressure influenced dinosaur communities. Higher small- to medium-sized prey availability leads to a normal body mass-species richness (M-S distribution of carnivorous dinosaurs (as found in the theropod fossil record, in contrast to the right-skewed M-S distribution of carnivorous mammals (as found living members of the order Carnivora. Higher levels of interspecific competition leads to a left-skewed M-S distribution in herbivorous dinosaurs (as found in sauropods and ornithopods, in contrast to the normal M-S distribution of large herbivorous mammals. Thus, our models suggest that differences in reproductive strategy, and consequently ontogeny, explain observed differences in community structure between dinosaur and mammal faunas. Models also show that the largest dinosaurian predators could have subsisted on similar-sized prey by including younger life stages of the largest herbivore species, but that large predators likely avoided prey much smaller than themselves because, despite predicted higher abundances of smaller than larger-bodied prey, contributions of small prey to biomass intake would be insufficient to satisfy meat requirements. A lack of large carnivores feeding on small prey

  16. Ecological interactions in dinosaur communities: influences of small offspring and complex ontogenetic life histories.

    Science.gov (United States)

    Codron, Daryl; Carbone, Chris; Clauss, Marcus

    2013-01-01

    Because egg-laying meant that even the largest dinosaurs gave birth to very small offspring, they had to pass through multiple ontogenetic life stages to adulthood. Dinosaurs' successors as the dominant terrestrial vertebrate life form, the mammals, give birth to live young, and have much larger offspring and less complex ontogenetic histories. The larger number of juveniles in dinosaur as compared to mammal ecosystems represents both a greater diversity of food available to predators, and competitors for similar-sized individuals of sympatric species. Models of population abundances across different-sized species of dinosaurs and mammals, based on simulated ecological life tables, are employed to investigate how differences in predation and competition pressure influenced dinosaur communities. Higher small- to medium-sized prey availability leads to a normal body mass-species richness (M-S) distribution of carnivorous dinosaurs (as found in the theropod fossil record), in contrast to the right-skewed M-S distribution of carnivorous mammals (as found living members of the order Carnivora). Higher levels of interspecific competition leads to a left-skewed M-S distribution in herbivorous dinosaurs (as found in sauropods and ornithopods), in contrast to the normal M-S distribution of large herbivorous mammals. Thus, our models suggest that differences in reproductive strategy, and consequently ontogeny, explain observed differences in community structure between dinosaur and mammal faunas. Models also show that the largest dinosaurian predators could have subsisted on similar-sized prey by including younger life stages of the largest herbivore species, but that large predators likely avoided prey much smaller than themselves because, despite predicted higher abundances of smaller than larger-bodied prey, contributions of small prey to biomass intake would be insufficient to satisfy meat requirements. A lack of large carnivores feeding on small prey exists in mammals

  17. Sex differences in cognitive ageing: testing predictions derived from life-history theory in a dioecious nematode.

    Science.gov (United States)

    Zwoinska, Martyna K; Kolm, Niclas; Maklakov, Alexei A

    2013-12-01

    Life-history theory maintains that organisms allocate limited resources to different traits to maximize fitness. Learning ability and memory are costly and known to trade-off with longevity in invertebrates. However, since the relationship between longevity and fitness often differs between the sexes, it is likely that sexes will differentially resolve the trade-off between learning and longevity. We used an established associative learning paradigm in the dioecious nematode Caenorhabditis remanei, which is sexually dimorphic for lifespan, to study age-related learning ability in males and females. In particular, we tested the hypothesis that females (the shorter-lived sex) show higher learning ability than males early in life but senesce faster. Indeed, young females outperformed young males in learning a novel association between an odour (butanone) and food (bacteria). However, while learning ability and offspring production declined rapidly with age in females, males maintained high levels of these traits until mid-age. These results not only demonstrate sexual dimorphism in age-related learning ability but also suggest that it conforms to predictions derived from the life-history theory. © 2013.

  18. Human evolution, life history theory, and the end of biological reproduction.

    Science.gov (United States)

    Last, Cadell

    2014-01-01

    Throughout primate history there have been three major life history transitions towards increasingly delayed sexual maturation and biological reproduction, as well as towards extended life expectancy. Monkeys reproduce later and live longer than do prosimians, apes reproduce later and live longer than do monkeys, and humans reproduce later and live longer than do apes. These life history transitions are connected to increased encephalization. During the last life history transition from apes to humans, increased encephalization co-evolved with increased dependence on cultural knowledge for energy acquisition. This led to a dramatic pressure for more energy investment in growth over current biological reproduction. Since the industrial revolution socioeconomic development has led to even more energy being devoted to growth over current biological reproduction. I propose that this is the beginning of an ongoing fourth major primate life history transition towards completely delayed biological reproduction and an extension of the evolved human life expectancy. I argue that the only fundamental difference between this primate life history transition and previous life history transitions is that this transition is being driven solely by cultural evolution, which may suggest some deeper evolutionary transition away from biological evolution is already in the process of occurring.

  19. Quality of Life Related to Visual Function in Three Young Adults with Mucopolysaccharidoses

    Directory of Open Access Journals (Sweden)

    Katherine L. Bergwerk

    2003-01-01

    Full Text Available The systemic mucopolysaccharidoses are complex syndromes, which may include corneal clouding as a mechanism leading to decreased vision and hence decreased quality of life. This study presents three young adult patients with mucopolysaccharidoses in order to compare their visual status through retrospective chart review, including patient and guardian interview, history, and examination, including a modified form of the VF-14 questionnaire (visual function with 14 questions.When the visual acuity and VF-14 results of the three patients were compared, the results of the VF-14 correlated with the patients� visual acuity status. The two patients who retained clear corneas or underwent penetrating keratoplasty had a wider range of social and physical activities, and an overall better quality of life than did the patient with decreased vision due to opacified corneas.We conclude that close monitoring of the ocular health of patients with storage syndromes that may compromise visual acuity must be stressed, and intervention to insure good vision is of the utmost importance to maintaining a good quality of life for these patients, especially as new therapies assist these patients to achieve increased longevity with better health.

  20. NARRATIVE: A short history of my life in science A short history of my life in science

    Science.gov (United States)

    Manson, Joseph R.

    2010-08-01

    I was certainly surprised, and felt extremely honored, when Salvador Miret-Artés suggested that he would like to organize this festschrift. Before that day I never anticipated that such an honor would come to me. I would like to thank Salvador for the large amount of time and work he has expended in organizing this special issue, the Editors of Journal of Physics: Condensed Matter for making it possible, and also the contributing authors for their efforts. My family home was outside of Petersburg, Virginia in Dinwiddie County in an area that was, during my youth, largely occupied by small farms. This is a region rich in American history and our earliest ancestors on both sides of the family settled in this area, beginning in the decade after the first Virginia settlement in Jamestown. My father was an engineer and my mother was a former school teacher, and their parents were small business owners. From earliest memories I recall being interested in finding out how things worked and especially learning about the wonders of nature. These interests were fostered by my parents who encouraged such investigations during long walks, visits to friends and relatives, and trips to museums. However, my earliest memory of wanting to become a scientist is associated with a Christmas gift of a chemistry set when I was about ten years old. I was absolutely fascinated by the amazing results that could be achieved with simple chemical reactions and realized then that I wanted to do something in life that would be associated with science. The gift of that small chemistry set developed over the next few years into a serious interest in chemistry, and throughout my junior high-school years I spent nearly all the money I earned doing odd jobs for neighbors on small laboratory equipment and chemical supplies, eventually taking over our old abandoned chicken house and turning it into a small chemistry lab. I remember being somewhat frustrated at the limits, mainly financial, that kept

  1. Life History Consequences of the Facultative Expression of a Dispersal Life Stage in the Phoretic Bulb Mite (Rhizoglyphus robini.

    Directory of Open Access Journals (Sweden)

    Jacques A Deere

    Full Text Available Life history traits play an important role in population dynamics and correlate, both positively and negatively, with dispersal in a wide range of taxa. Most invertebrate studies on trade-offs between life history traits and dispersal have focused on dispersal via flight, yet much less is known about how life history trade-offs influence species that disperse by other means. In this study, we identify effects of investing in dispersal morphology (dispersal expression on life history traits in the male dimorphic bulb mite (Rhizoglyphus robini. This species has a facultative juvenile life stage (deutonymph during which individuals can disperse by phoresy. Further, adult males are either fighters (which kill other mites or benign scramblers. Here, in an experiment, we investigate the effects of investing in dispersal on size at maturity, sex and male morph ratio, and female lifetime reproductive success. We show that life history traits correlate negatively with the expression of the dispersal stage. Remarkably, all males that expressed the dispersal life stage developed into competitive fighters and none into scramblers. This suggests that alternative, male reproductive strategies and dispersal should not be viewed in isolation but considered concurrently.

  2. Life history variation in Barents Sea fish: implications for sensitivity to fishing in a changing environment.

    Science.gov (United States)

    Wiedmann, Magnus A; Primicerio, Raul; Dolgov, Andrey; Ottesen, Camilla A M; Aschan, Michaela

    2014-09-01

    Under exploitation and environmental change, it is essential to assess the sensitivity and vulnerability of marine ecosystems to such stress. A species' response to stress depends on its life history. Sensitivity to harvesting is related to the life history "fast-slow" continuum, where "slow" species (i.e., large, long lived, and late maturing) are expected to be more sensitive to fishing than "fast" ones. We analyze life history traits variation for all common fish species in the Barents Sea and rank fishes along fast-slow gradients obtained by ordination analyses. In addition, we integrate species' fast-slow ranks with ecosystem survey data for the period 2004-2009, to assess life history variation at the community level in space and time. Arctic fishes were smaller, had shorter life spans, earlier maturation, larger offspring, and lower fecundity than boreal ones. Arctic fishes could thus be considered faster than the boreal species, even when body size was corrected for. Phylogenetically related species possessed similar life histories. Early in the study period, we found a strong spatial gradient, where members of fish assemblages in the southwestern Barents Sea displayed slower life histories than in the northeast. However, in later, warmer years, the gradient weakened caused by a northward movement of boreal species. As a consequence, the northeast experienced increasing proportions of slower fish species. This study is a step toward integrating life history traits in ecosystem-based areal management. On the basis of life history traits, we assess the fish sensitivity to fishing, at the species and community level. We show that climate warming promotes a borealization of fish assemblages in the northeast, associated with slower life histories in that area. The biology of Arctic species is still poorly known, and boreal species that now establish in the Arctic are fishery sensitive, which calls for cautious ecosystem management of these areas.

  3. History of major depressive disorder prospectively predicts worse quality of life in women with breast cancer.

    Science.gov (United States)

    Jim, Heather S L; Small, Brent J; Minton, Susan; Andrykowski, Michael; Jacobsen, Paul B

    2012-06-01

    Data are scarce about whether past history of major depressive disorder in the absence of current depression places breast cancer patients at risk for worse quality of life. The current study prospectively examined quality of life during chemotherapy in breast cancer patients with a history of resolved major depressive disorder (n = 29) and no history of depression (n = 144). Women with Stages 0-II breast cancer were assessed prior to and at the completion of chemotherapy. Major depressive disorder was assessed via structured interview and quality of life with the SF-36. Patients with past major depressive disorder displayed greater declines in physical functioning relative to patients with no history of depression (p ≤ 0.01). Findings suggest that breast cancer patients with a history of resolved major depressive disorder are at increased risk for declines in physical functioning during chemotherapy relative to patients with no history of depression.

  4. History of Major Depressive Disorder Prospectively Predicts Worse Quality of Life in Women with Breast Cancer

    Science.gov (United States)

    Small, Brent J.; Minton, Susan; Andrykowski, Michael; Jacobsen, Paul B.

    2012-01-01

    Background Data are scarce about whether past history of major depressive disorder in the absence of current depression places breast cancer patients at risk for worse quality of life. Purpose The current study prospectively examined quality of life during chemotherapy in breast cancer patients with a history of resolved major depressive disorder (n=29) and no history of depression (n=144). Methods Women with Stages 0–II breast cancer were assessed prior to and at the completion of chemotherapy. Major depressive disorder was assessed via structured interview and quality of life with the SF-36. Results Patients with past major depressive disorder displayed greater declines in physical functioning relative to patients with no history of depression (p≤0.01). Conclusions Findings suggest that breast cancer patients with a history of resolved major depressive disorder are at increased risk for declines in physical functioning during chemotherapy relative to patients with no history of depression. PMID:22167580

  5. Observations on the Life Histories and Behaviour of some Small ...

    African Journals Online (AJOL)

    box traps built about a common snap mouse trap. The traps were baited with quick-cooking rolled oats as common rolled oats will not attract wild mice. Each mouse was ... In the following pages all pregnant mice detained were provided with two or three weaverbird nests in which to have their families. The young were ...

  6. Life history strategies of fish species and biodiversity in eastern USA streams

    Science.gov (United States)

    Meador, Michael R.; Brown, Larry M.

    2015-01-01

    Predictive models have been used to determine fish species that occur less frequently than expected (decreasers) and those that occur more frequently than expected (increasers) in streams in the eastern U.S. Coupling life history traits with 51 decreaser and 38 increaser fish species provided the opportunity to examine potential mechanisms associated with predicted changes in fish species distributions in eastern streams. We assigned six life history traits – fecundity, longevity, maturation age, maximum total length, parental care, and spawning season duration – to each fish species. Decreaser species were significantly smaller in size and shorter-lived with reduced fecundity and shorter spawning seasons compared to increaser species. Cluster analysis of traits revealed correspondence with a life history model defining equilibrium (low fecundity, high parental care), opportunistic (early maturation, low parental care), and periodic (late maturation, high fecundity, low parental care) end-point strategies. Nearly 50 % of decreaser species were associated with an intermediate opportunistic-periodic strategy, suggesting that abiotic factors such as habitat specialization and streamflow alteration may serve as important influences on life history traits and strategies of decreaser species. In contrast, the percent of increaser species among life history strategy groups ranged from 21 to 32 %, suggesting that life history strategies of increaser species were more diverse than those of decreaser species. This study highlights the utility of linking life history theory to biodiversity to better understand mechanisms that contribute to fish species distributions in the eastern U.S.

  7. Dynamics of body time, social time and life history at adolescence.

    Science.gov (United States)

    Worthman, Carol M; Trang, Kathy

    2018-02-21

    Recent opposing trends towards earlier physical maturation and later social maturation present a conundrum of apparent biological-social mismatch. Here we use life history analysis from evolutionary ecology to identify forces that drive these shifts. Together with findings in developmental science, our life history analysis indicates that adolescence is a distinctive period for biological embedding of culture. Ethnographic evidence shows that mass education is a novel feature of the globalizing cultural configurations of adolescence, which are driven by transformations in labour, livelihood and lifestyle. Evaluation of the life history trade-offs and sociocultural ecologies that are experienced by adolescents may offer a practical basis for enhancing their development.

  8. Dynamics of body time, social time and life history at adolescence

    Science.gov (United States)

    Worthman, Carol M.; Trang, Kathy

    2018-02-01

    Recent opposing trends towards earlier physical maturation and later social maturation present a conundrum of apparent biological-social mismatch. Here we use life history analysis from evolutionary ecology to identify forces that drive these shifts. Together with findings in developmental science, our life history analysis indicates that adolescence is a distinctive period for biological embedding of culture. Ethnographic evidence shows that mass education is a novel feature of the globalizing cultural configurations of adolescence, which are driven by transformations in labour, livelihood and lifestyle. Evaluation of the life history trade-offs and sociocultural ecologies that are experienced by adolescents may offer a practical basis for enhancing their development.

  9. Evidence for an age-dependent influence of environmental variations on a long-lived seabird's life-history traits.

    Science.gov (United States)

    Pardo, Deborah; Barbraud, Christophe; Authier, Matthieu; Weimerskirch, Henri

    2013-01-01

    Theoretical and empirical studies have highlighted the effects of age on several life-history traits in wild populations. There is also increasing evidence for environmental effects on their demographic traits. However, quantifying how individuals differentially respond to environmental variations according to their age remains a challenge in ecology. In a population of Black-browed Albatrosses monitored during 43 years, we analyzed how life-history traits varied according to age, and whether individuals of different ages responded in different ways to environmental conditions. To do so, we: (1) examined how age affected seven life-history traits, (2) investigated differences in temporal variance of demographic traits between age classes, and (3) tested for age-dependent effects of climate and fisheries covariates on demographic traits. Overall, there was a tendency for traits to improve during the first years of life (5-10 years), to peak and remain stable at middle age (10-30 years), and decline at old ages. At young ages, survival and reproductive parameters increased, except offspring body condition at fledging, suggesting that younger parents had already acquired good foraging capacities. However, they suffered from inexperience in breeding as suggested by their higher breeding failures during incubation. There was evidence for reproductive and actuarial senescence. In particular, breeding success and offspring body condition declined abruptly, suggesting altered foraging capacities of old individuals. Middle-aged individuals had the lowest temporal variance of demographic traits. Although this is predicted by the theory of environmental canalization, it could also results from a higher susceptibility of young and old birds due to their respective inexperience and senescence. The highest temporal variances were found in old individuals. Survival was significantly influenced by sea surface temperatures in the foraging zone of this albatross population during

  10. Relationship between family quality of life and day occupations of young people with Down syndrome.

    Science.gov (United States)

    Foley, Kitty-Rose; Girdler, Sonya; Downs, Jenny; Jacoby, Peter; Bourke, Jenny; Lennox, Nick; Einfeld, Stewart; Llewellyn, Gwynnyth; Parmenter, Trevor R; Leonard, Helen

    2014-09-01

    To explore relationships between family quality of life, day occupations and activities of daily living (ADL) of young persons with Down syndrome. Data were collected from 150 families with a young person with Down syndrome aged 16-30 years participating in the Down syndrome "Needs Opinions Wishes" database. Data described the young person's characteristics (including functional abilities, behaviour and day occupations) and family characteristics (including income, family and community supports and quality of life). Compared to families of young people attending open employment, families of young people participating in sheltered employment tended to report poorer family quality of life, after adjusting for personal characteristics, behaviour and income (coeff -6.78, 95 % CI -14.38, 0.81). Family supports reduced this relationship (coeff -6.00, 95 % CI -12.76, 0.76). Families of young people with greater functioning in ADL reported better family quality of life regardless of personal and environmental factors (coeff 0.45, 95 % CI 0.05, 0.85) and inclusion of family factors such as family supports reduced this association (coeff 0.29, 95 % CI -0.10, 0.67). Participation of young people with Down syndrome in open employment may positively influence family quality of life. Services that facilitate functioning in ADL and assist the families in accessing suitable family supports have the potential to positively influence family quality of life.

  11. Daily life historyasmodern direction of urban history of Englandof High Middle Ages

    Directory of Open Access Journals (Sweden)

    O. S. Okhrimenko

    2014-07-01

    Full Text Available Historiographical review of recent research is an important aspect of the scientific study of the problems of medieval urban history of England. In 2000s there was marked the beginning of years of studying the history of everyday of medieval towns. The most important works in this field are the studies of Professor C. Dyer. Studying the history of everyday life of the city the researcher has identified as «standards of living». One of the modern directions of the history of everyday life is a history of food. There is the significant research of Professor M. Carlin on the history of English feasting of urban residents of the Middle Ages. In the article Fast food and urban living standards in medieval England, she looked anew at the narrative sources XII-XIV centuries. Another area of daily life history is a history of clothes (fashion. L. A. Wilson in his work De novo modo: The birth of fashion in the Middle Ages analyzes comprehensively the written, visual, and archaeological evidence. Modern interpretations of medieval hygiene (including sanitation of medieval towns related to research in the area of a history body. Its appointed destination for British urban sources dealing D. Jorgensen, D. Keene, U. Ewert, G. Geltner, J. Lee etc. They revised the traditional view medievalists of the nineteenth century. At the present period the historiography of medieval towns of England are mostly social history. Towards the history of everyday life there is a tendency to positive characteristics of urban life in the English Middle Ages. Contemporary scholars refer to the current trends in the world. Active urbanization processes forced researchers to seek appeal of such a way of life in previous centuries, particularly in the Middle Ages. The key features of everyday modern city (commercialization, fast food, fashion, high standards of hygiene etc. historians find their roots in the past.

  12. Life stress and family history for depression: the moderating role of past depressive episodes.

    Science.gov (United States)

    Monroe, Scott M; Slavich, George M; Gotlib, Ian H

    2014-02-01

    Three of the most consistently reported and powerful predictors of depression are a recent major life event, a positive family history for depression, and a personal history of past depressive episodes. Little research, however, has evaluated the inter-relations among these predictors in depressed samples. Such information is descriptively valuable and potentially etiologically informative. In the present article we summarize the existing literature and test four predictions in a sample of 62 clinically depressed individuals: (1) participants who experienced a major life event prior to onset would be less likely than participants who did not experience a major life event to have a positive family history for depression; (2) participants with a recent major life event would have fewer lifetime episodes of depression than would participants without; (3) participants with a positive family history for depression would have more lifetime episodes of depression than would participants with a negative family history for depression; and (4) we would obtain a 3-way interaction in which participants with a positive family history and without a major life event would have the most lifetime episodes, whereas participants with a negative family history and a major life event would have the fewest lifetime episodes. The first three predictions were confirmed, and the fourth prediction partially confirmed. These novel findings begin to elucidate the complex relations among these three prominent risk factors for depression, and point to avenues of research that may help illuminate the origins of depressive episodes. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Loss of Sphingosine Kinase Alters Life History Traits and Locomotor Function in Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Jason P. Chan

    2017-09-01

    Full Text Available Sphingolipid metabolism is important to balance the abundance of bioactive lipid molecules involved in cell signaling, neuronal function, and survival. Specifically, the sphingolipid sphingosine mediates cell death signaling, whereas its phosphorylated form, sphingosine-1-phosphate (S1P, mediates cell survival signaling. The enzyme sphingosine kinase produces S1P, and the activity of sphingosine kinase impacts the ability of cells to survive under stress and challenges. To examine the influence of sphingolipid metabolism, particularly enzymes regulating sphingosine and S1P, in mediating aging, neuronal function and stress response, we examined life history traits, locomotor capacities and heat stress responses of young and old animals using the model organism Caenorhabditis elegans. We found that C. elegans sphk-1 mutants, which lack sphingosine kinase, had shorter lifespans, reduced brood sizes, and smaller body sizes compared to wild type animals. By analyzing a panel of young and old animals with genetic mutations in the sphingolipid signaling pathway, we showed that aged sphk-1 mutants exhibited a greater decline in neuromuscular function and locomotor behavior. In addition, aged animals lacking sphk-1 were more susceptible to death induced by acute and prolonged heat exposure. On the other hand, older animals with loss of function mutations in ceramide synthase (hyl-1, which converts sphingosine to ceramide, showed improved neuromuscular function and stress response with age. This phenotype was dependent on sphk-1. Together, our data show that loss of sphingosine kinase contributes to poor animal health span, suggesting that sphingolipid signaling may be important for healthy neuronal function and animal stress response during aging.

  14. Heterogeneity of life histories in a nonhuman primate population

    DEFF Research Database (Denmark)

    Hernández Pacheco, Raisa; Steiner, Uli

    2014-01-01

    histories within a primate population is generated by density-dependent dynamics, the demographic data of Cayo Santiago rhesus macaques over 40 years and 7000 individuals was used. A multi-stage model using a first-order Markov process describing reproductive dynamics was constructed and annual entropy...

  15. Work–Life Balance: History, Costs, and Budgeting for Balance

    OpenAIRE

    Raja, Siva; Stein, Sharon L.

    2014-01-01

    The concept and difficulties of work–life balance are not unique to surgeons, but professional responsibilities make maintaining a work–life balance difficult. Consequences of being exclusively career focused include burn out, physical, and mental ailments. In addition, physician burn out may hinder optimal patient care and incur significant costs on health care in general. Assessing current uses of time, allocating goals catered to an individual surgeon, and continual self-assessment may hel...

  16. Late-Life and Life History Predictors of Older Adults of High-Risk Alcohol Consumption and Drinking Problems

    Science.gov (United States)

    Moos, Rudolf H.; Schutte, Kathleen K.; Brennan, Penny L.; Moos, Bernice S.

    2009-01-01

    Aims This prospective, longitudinal study focused on late-life and life history predictors of high-risk alcohol consumption and drinking problems during a 20-year interval as adults matured from age 55–65 to age 75–85. Design, Setting, Participants A sample of older community residents (N=719) who had consumed alcohol in the past year or shortly before was surveyed at baseline and 10 years and 20 years later. Measurements At each contact point, participants completed an inventory that assessed their alcohol consumption, drinking problems, and personal and life context factors. Participants also provided information about their life history of drinking and help-seeking. Results Older adults who, at baseline, had more friends who approved of drinking, relied on substances for tension reduction, and had more financial resources were more likely to engage in high-risk alcohol consumption and to incur drinking problems at 10-year and 20-year follow-ups. With respect to life history factors, drinking problems by age 50 were associated with a higher likelihood of late-life high-risk alcohol consumption and drinking problems; having tried to cut down on drinking and participation in Alcoholics Anonymous were associated with a lower likelihood of high-risk consumption and problems. Conclusion Specific late-life and life history factors can identify older adults likely to engage in excessive alcohol consumption 10 and 20 years later. Targeted screening that considers current alcohol consumption and life context, and history of drinking problems and help-seeking, could help identify older adults at higher risk for excessive or problematic drinking. PMID:19969428

  17. Late-life and life history predictors of older adults' high-risk alcohol consumption and drinking problems.

    Science.gov (United States)

    Moos, Rudolf H; Schutte, Kathleen K; Brennan, Penny L; Moos, Bernice S

    2010-04-01

    This prospective, longitudinal study focused on late-life and life history predictors of high-risk alcohol consumption and drinking problems during a 20-year interval as adults matured from age 55-65 to 75-85. A sample of older community residents (N=719) who had consumed alcohol in the past year or shortly before was surveyed at baseline and 10 and 20 years later. At each contact point, participants completed an inventory that assessed their alcohol consumption, drinking problems, and personal and life context factors. Participants also provided information about their life history of drinking and help-seeking. Older adults who, at baseline, had more friends who approved of drinking, relied on substances for tension reduction, and had more financial resources were more likely to engage in high-risk alcohol consumption and to incur drinking problems at 10- and 20-year follow-ups. With respect to life history factors, drinking problems by age 50 were associated with a higher likelihood of late-life high-risk alcohol consumption and drinking problems; having tried to cut down on drinking and participation in Alcoholics Anonymous were associated with a lower likelihood of high-risk consumption and problems. Specific late-life and life history factors can identify older adults likely to engage in excessive alcohol consumption 10 and 20 years later. Targeted screening that considers current alcohol consumption and life context, and history of drinking problems and help-seeking, could help identify older adults at higher risk for excessive or problematic drinking. Published by Elsevier Ireland Ltd.

  18. Timing of seasonal migration in mule deer: effects of climate, plant phenology, and life-history characteristics

    Science.gov (United States)

    Monteith, Kevin L.; Bleich, Vernon C.; Stephenson, Thomas R.; Pierce, Beck M.; Conner, Mary M.; Klaver, Robert W.; Bowyer, R. Terry

    2011-01-01

    Phenological events of plants and animals are sensitive to climatic processes. Migration is a life-history event exhibited by most large herbivores living in seasonal environments, and is thought to occur in response to dynamics of forage and weather. Decisions regarding when to migrate, however, may be affected by differences in life-history characteristics of individuals. Long-term and intensive study of a population of mule deer (Odocoileus hemionus) in the Sierra Nevada, California, USA, allowed us to document patterns of migration during 11 years that encompassed a wide array of environmental conditions. We used two new techniques to properly account for interval-censored data and disentangle effects of broad-scale climate, local weather patterns, and plant phenology on seasonal patterns of migration, while incorporating effects of individual life-history characteristics. Timing of autumn migration varied substantially among individual deer, but was associated with the severity of winter weather, and in particular, snow depth and cold temperatures. Migratory responses to winter weather, however, were affected by age, nutritional condition, and summer residency of individual females. Old females and those in good nutritional condition risked encountering severe weather by delaying autumn migration, and were thus risk-prone with respect to the potential loss of foraging opportunities in deep snow compared with young females and those in poor nutritional condition. Females that summered on the west side of the crest of the Sierra Nevada delayed autumn migration relative to east-side females, which supports the influence of the local environment on timing of migration. In contrast, timing of spring migration was unrelated to individual life-history characteristics, was nearly twice as synchronous as autumn migration, differed among years, was related to the southern oscillation index, and was influenced by absolute snow depth and advancing phenology of plants

  19. A true love story. Young people's romantic and sexual development in the context of everyday life

    Directory of Open Access Journals (Sweden)

    Henderien Steenbeek

    2017-06-01

    Full Text Available Wieke Dalenberg. A true love story. Young people’s romantic and sexual development in the context of everyday life. Groningen: University of Groningen, 2016, 147 p., ISBN 978 94 6332 100 6

  20. Transitions from School for Young Adults with Intellectual Disability: Parental Perspectives on "Life as an Adjustment"

    Science.gov (United States)

    Davies, Michael D.; Beamish, Wendi

    2009-01-01

    Background: Few studies have investigated transition programs and outcomes for young adults with disabilities as viewed from the parent perspective. The current Australian study provided a voice for parents to report on the experiences of and outcomes for young adults following their recent transition from school into post-school life. Method: A…

  1. The Relationship between the Self-Efficacy and Life Satisfaction of Young Adults

    Science.gov (United States)

    Çakar, Firdevs Savi

    2012-01-01

    The aim of this study is to examine the relationship between self-efficacy and life satisfaction of young adults. This study is cross-sectional study and variables. Data were collected between March 2012 and April 2012 from young adults who were bachelor degree and attending the Celal Bayar University Pedagogical Formation Program the academic…

  2. Life Course Stage in Young Adulthood and Intergenerational Congruence in Family Attitudes

    Science.gov (United States)

    Bucx, Freek; Raaijmakers, Quinten; van Wel, Frits

    2010-01-01

    We investigated how intergenerational congruence in family-related attitudes depends on life course stage in young adulthood. Recent data from the Netherlands Kinship Panel Study were used; the present sample included 2,041 dyads of young adults and their parents. Findings are discussed in terms of the elasticity in intergenerational attitude…

  3. Voices of Young Adults with Autism and Their Perspective on Life Choices after Secondary Education

    Science.gov (United States)

    Galler, Susan

    2013-01-01

    The purpose of this phenomenological qualitative research study was to explore how young adults who have an autism spectrum disorder perceive their life choices after secondary education. The focus participants in the sample were young adults with Autism Spectrum Disorder (ASD). For the purpose of this research, ASD includes autism and Asperger's…

  4. The reminiscence bump reconsidered: Children's prospective life stories show a bump in young adulthood

    DEFF Research Database (Denmark)

    Bohn, Annette; Berntsen, Dorthe

    2011-01-01

    showed a clear bump in young adulthood. In Study 2, children were prompted by word cues to write down events from their future lives. The events generated consisted mostly of non-life-script events, and those events did not show a bump in young adulthood. Our findings challenge prevailing explanations...

  5. Natural history of idiopathic abducens nerve paresis in a young adult.

    Science.gov (United States)

    Hussaindeen, Jameel Rizwana; Mani, Revathy; Rakshit, Archayeeta; Ramasubramanian, Srikanth; Vittal Praveen, Smitha

    2016-01-01

    The natural history of idiopathic abducens nerve paresis and the role of conservative management such as vision training during the recovery process is not well documented in the literature to the best of our knowledge. This case report presents the natural recovery process of idiopathic abducens nerve paresis in a young adult and the role of vision therapy in the recovery process. Copyright © 2016 Spanish General Council of Optometry. Published by Elsevier España, S.L.U. All rights reserved.

  6. The life-history of a springtail Folsomia candida living in soil contaminated with nonylphenol

    DEFF Research Database (Denmark)

    Widarto, T. H.; Krogh, P. H.; Forbes, V.

    Nonylphenol (NP) has been known for long time as a suspected endocrine disruptor in animals. We have conducted an experiment to look at the effect of NP on the life-history of the parthenogenetic springtail, Folsomia candida. Six sub-lethal concentrations (0, 8,16, 24, 32, 40 mg/kg dry soil......) were applied to 6 replicates of soil containing an individual of 0-1 day old juvenile. During continuous exposure (63 days), we assessed springtail life-history traits such as: survival, growth rate, molting time, time between molting, time to first reproduction, egg production, and viability...... population growth rate (l). Decomposition analysis to investigate the contribution of each of the affected life-history traits to the effects observed on l, and elasticity analysis to examine the relative sensitivity of l to changes in each of the life history traits provided valuable insight...

  7. Energy and water budgets of larks in a life history perspective : Parental effort varies with aridity

    NARCIS (Netherlands)

    Tieleman, BI; Williams, JB; Visser, GH

    We compared physiological, demographic, and ecological variables of larks to gain insights into life history variation along an aridity gradient, incorporating phylogenetic relationships in analyses when appropriate. Quantifying field metabolic rate (FMR). and water influx rate (WIR) of parents

  8. Snake River fall Chinook reproductive success - Juvenile life history changes in Snake River fall Chinook salmon

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This population historically migrated as subyearling smolts, but in recent years, the yearling life history has become more common. Environmental conditions...

  9. Otolith output - Project to study alternative life history types of fall Chinook based on otoliths

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The life-history complexity of Snake River fall Chinook salmon has hindered efforts to manage the ESU. In particular, the existence of an overwintering behavior in a...

  10. Chum and pink salmon genetics - Genetic and life history variation of southern chum and pink salmon

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The distribution of genetic and life history variation in chum (Oncorhynchus keta) and pink (O. gorbuscha) salmon in their southern range in North America is key to...

  11. Negative effects of UVB-irradiated phytoplankton on life history traits and fitness of Daphnia magna

    NARCIS (Netherlands)

    Lange, de H.J.; Reeuwijk, van P.L.

    2003-01-01

    1. We tested the effect of ultraviolet-B (UVB)-irradiated phytoplankton on life history characteristics of Daphnia magna . Two phytoplankton species were used, Chlamydomonas reinhardtii and Cryptomonas pyrenoidifera . The phytoplankton species were cultured under photosynthetically active radiation

  12. COPEPOD REPRODUCTIVE STRATEGIES: LIFE-HISTORY THEORY, PHYLOGENETIC PATTERN AND INVASION OF INLAND WATERS. (R824771)

    Science.gov (United States)

    AbstractLife-history theory predicts that different reproductive strategies should evolve in environments that differ in resource availability, mortality, seasonality, and in spatial or temporal variation. Within a population, the predicted optimal strategy is driven ...

  13. Disparate relatives: Life histories vary more in genera occupying intermediate environments

    Czech Academy of Sciences Publication Activity Database

    Hermant, M.; Hennion, F.; Bartish, Igor V.; Yugel, B.; Prinzing, A.

    2012-01-01

    Roč. 14, č. 4 (2012), s. 283-301 ISSN 1433-8319 Institutional support: RVO:67985939 Keywords : life-history traits * dated phylogeny * regional trait variability Subject RIV: EF - Botanics Impact factor: 4.158, year: 2012

  14. Behavioral and life-history evidence for interspecific competition in the larvae of two heliconian butterflies

    Science.gov (United States)

    Millan, Carolina; Borges, Simone Silva; Rodrigues, Daniela; Moreira, Gilson Rudinei Pires

    2013-10-01

    Interspecific competition in herbivorous insects remains a controversial issue. To date, many studied systems have not met assumptions of the traditional competition theory, and a new paradigm has been emerging. We examined the behavioral and life-history consequences of common host plant use of Heliconius erato and Dryas iulia (Nymphalidae) in relation to Passiflora suberosa (Passifloraceae). Larvae of the former use the apical portion of this host; the latter is presumably able to explore all plant parts. We assessed host use pattern in relation to leaf age, when reared either alone ( D. iulia) or together ( D. iulia and H. erato). Larval feeding choice tests with respect to leaf age were performed, and performance was recorded. Observations were made to assess antagonistic behavior of H. erato and D. iulia towards each other, if any. Similarly to H. erato, D. iulia fed on the young leaves significantly more than the mature ones; larvae were not induced to prefer mature leaves. First instars of H. erato used only the apical parts of P. suberosa and displayed aggressive behavior towards D. iulia, which moved to the lower shoot portions. Larval mortality and development time of both species significantly increased when reared together; such performance costs were more pronounced in D. iulia than H. erato. Our study gathers evidences that use of P. suberosa by these heliconian butterflies represent a case of competitive exclusion resulting in niche differentiation, where costs are higher for D. iulia than H. erato.

  15. Can sexual selection drive female life histories? A comparative study on Galliform birds

    OpenAIRE

    Kolm, N.; Stein, R. W.; Mooers, A. O.; Verspoor, J. J.; Cunningham, E. J. A.

    2007-01-01

    Sexual selection has been identified as a major evolutionary force shaping male life history traits but its impact on female life history evolution is less clear. Here we examine the impact of sexual selection on three key female traits (body size, egg size and clutch size) in Galliform birds. Using comparative independent contrast analyses and directional DISCRETE analyses, based on published data and a new genera-level supertree phylogeny of Galliform birds, we investigated how sexual selec...

  16. Rapid onset pressor response to exercise in young women with a family history of hypertension.

    Science.gov (United States)

    Matthews, Evan L; Greaney, Jody L; Wenner, Megan M

    2017-09-01

    What is the central question of this study? Alterations in blood pressure control at exercise onset are apparent in older adults with established cardiovascular disease. It is currently not known whether these alterations are evident in young adults with a family history of hypertension. What is the main finding and its importance? We demonstrate that young women with a family history of hypertension display a larger change in blood pressure within the first 10 s of isometric exercise. These data suggest altered blood pressure control in young women with a family history of hypertension. Hypertensive adults demonstrate atypical increases in blood pressure (BP) and muscle sympathetic nerve activity (MSNA) at the immediate onset of static muscle contraction. However, it is unknown whether these abnormal responses occur in young, otherwise healthy adults at risk for developing future disease, such as those with a family history of hypertension (+FH). We tested the hypothesis that +FH young women have exaggerated increases in BP and MSNA at the onset of static muscle contraction compared with those without a family history of hypertension (-FH). We retrospectively examined beat-by-beat BP and MSNA during the initial 30 s of isometric handgrip exercise (30% of maximal voluntary contraction) in 16 +FH (22 ± 2 years old, 22 ± 3 kg m -2 ) and 16 -FH (22 ± 3 years old, 22 ± 3 kg m -2 ) women. Resting mean arterial pressure (+FH 80 ± 11 mmHg versus -FH 84 ± 13 mmHg), MSNA burst frequency (+FH 7 ± 3 bursts min -1 versus -FH 9 ± 5 bursts min -1 ) and burst incidence [+FH 12 ± 4 bursts (100 heart beats) -1 versus -FH 12 ± 8 bursts (100 heart beats) -1 ] were similar between groups (all P > 0.05). Within the first 10 s of exercise, changes in mean arterial pressure (+FH Δ8 ± 6 mmHg versus -FH Δ3 ± 2 mmHg, P exercise was not different between groups (-FH 7 ± 5 bursts min -1 versus +FH 9 ± 3 bursts min -1

  17. Social connectedness, stressful life events, and self-injurious thoughts and behaviors among young adults.

    Science.gov (United States)

    Macrynikola, Natalia; Miranda, Regina; Soffer, Ariella

    2018-01-01

    Preventing self-injurious thoughts and behaviors (SITBs) is particularly challenging on commuter campuses, given lower social cohesion and higher levels of stress than among traditional college populations. The present study examined the relationship between stressful life events (SLEs) and risk for different forms of SITBs, along with the potential buffering role of social connectedness, in a diverse sample of young adults from a commuter college. Participants were 1712 (81% female; 61% racial/ethnic minority; 20% sexual minority) undergraduate and graduate students from a public commuter college in New York City. Participants completed an anonymous survey that inquired about lifetime and recent (past 12months) history of suicidal ideation, suicide attempts, and non-suicidal self-injury (NSSI), along with social connectedness and lifetime history of SLEs. Lower levels of social connectedness and exposure to a higher number of SLEs were associated with engaging in SITBs in the past year, particularly both suicide attempts and non-suicidal self-injury. However, social connectedness did not buffer against the impact of SLEs on SITBs. Data are cross-sectional, limiting conclusions about directionality, and females were overrepresented. Identifying ways to increase social connectedness on diverse commuter campuses may help decrease risk of SITBs. However, it may not buffer against the impact of SLEs on risk of SITBs. Future studies should examine contextual variables (e.g., type and timing of social support) that may play a role in protecting against SITBs, particularly for those with a history of adversity. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Modernization and gender regimes, life histories of the wives of Turkish political leaders

    NARCIS (Netherlands)

    Yelsali Parmaksiz, Pinar Melis

    2009-01-01

    This work is a close look at the life histories of the top Turkish political leaders with the aim of analyzing changes in gender role and gender identity and tensions between the two in the history of Turkish modernization vis-à-vis with contemporaneous debates on gender. The main objective is to

  19. Work-life balance: history, costs, and budgeting for balance.

    Science.gov (United States)

    Raja, Siva; Stein, Sharon L

    2014-06-01

    The concept and difficulties of work-life balance are not unique to surgeons, but professional responsibilities make maintaining a work-life balance difficult. Consequences of being exclusively career focused include burn out, physical, and mental ailments. In addition, physician burn out may hinder optimal patient care and incur significant costs on health care in general. Assessing current uses of time, allocating goals catered to an individual surgeon, and continual self-assessment may help balance time, and ideally will help prevent burn out.

  20. Do pioneers have r-selected traits? Life history patterns among colonizing terrestrial gastropods.

    Science.gov (United States)

    Bengtsson, J; Baur, B

    1993-05-01

    We examine whether pioneer species of terrestrial gastropods (snails and slugs) possess particular life history traits commonly associated with r-selection, using data on gastropod colonization in four areas in north-west Europe (the Kvarken and Tvärminne archipelagos in the Baltic, polder woods in IJsselmeer, and a rehabilitated quarry near Maastricht). Data on age at first reproduction, longevity, clutch size, egg size and lifetime fecundity were gathered from the literature. In order to control for potentially confounding effects of body size on life history traits, we compared the residuals from the allometric relations between life history traits and body size for pioneers and non-pioneers. In snails, all life history traits examined were related to body size. In slugs, all traits except age at first reproduction scaled with body size. Body sizes did not differ between pioneers and non-pioneers in any area. In all four areas, there were no significant differences between pioneers and non-pioneers in any of the life history traits examined, after body size had been taken into account. This indicates that pioneer terrestrial gastropods generally cannot be regarded as r-selected. Pioneer species may possess any of several life history strategies, and the combinations of traits shown by them may have little in common with the r-K selection concept.

  1. Evolution of monogamy, paternal investment, and female life history in Peromyscus.

    Science.gov (United States)

    Jašarević, Eldin; Bailey, Drew H; Crossland, Janet P; Dawson, Wallace D; Szalai, Gabor; Ellersieck, Mark R; Rosenfeld, Cheryl S; Geary, David C

    2013-02-01

    The timing of reproductive development and associated trade-offs in quantity versus quality of offspring produced across the life span are well documented in a wide range of species. The relation of these aspects of maternal life history to monogamy and paternal investment in offspring is not well studied in mammals, due in part to the rarity of the latter. By using five large, captive-bred populations of Peromyscus species that range from promiscuous mating with little paternal investment (P. maniculatus bairdii) to social and genetic monogamy with substantial paternal investment (P. californicus insignis), we modeled the interaction between monogamy and female life history. Monogamy and high paternal investment were associated with smaller litter size, delayed maternal reproduction that extended over a longer reproductive life span, and larger, higher quality offspring. The results suggest monogamy and paternal investment can alter the evolution of female life-history trajectories in mammals. PsycINFO Database Record (c) 2013 APA, all rights reserved

  2. The combined effects of parental divorce and parental history of depression on cannabis use in young adults in France.

    Science.gov (United States)

    Sakyi, Kwame S; Melchior, Maria; Chollet, Aude; Surkan, Pamela J

    2012-11-01

    The joint effects of multiple social risk factors on substance use, such as parental divorce and parental history of depression, have rarely been studied in young adult offspring. We examined the combined effects of parental divorce and parental history of depression on current cannabis use among a community sample of young adults in France. Parental divorce was ascertained as divorce or separation before 2009. Parental history of depression based on parental reports of depression (1989-2009) and offspring reports of parental lifetime history of depression. Current cannabis use was defined as use at least once in the preceding 12 months. Data were analyzed using multiple logistic regression models controlling for young adult and parental socio-demographic variables. Approximately one fourth of youth (23%) reported consuming cannabis at least once in the past year. At the same time, 15% had parents who were divorced and 30% parents with a history of depression. The association between parental divorce and cannabis use in young adults was not statistically significant (adjusted OR: 1.50; 95% CI: 0.97-2.31). History of parental depression conferred a marginally statistically significant 42% higher odds of young adult cannabis use (adjusted OR: 1.42; 95% CI: 1.00-2.01). Young adults who experienced both parental history of divorce and depression were more than two times as likely to be current cannabis users compared to those who experienced neither of these (adjusted OR: 2.38; 95% CI: 1.26-4.48). Our findings highlight the critical importance of considering familial context in understanding cannabis use in young adults. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  3. The Tsimane Health and Life History Project: Integrating anthropology and biomedicine.

    Science.gov (United States)

    Gurven, Michael; Stieglitz, Jonathan; Trumble, Benjamin; Blackwell, Aaron D; Beheim, Bret; Davis, Helen; Hooper, Paul; Kaplan, Hillard

    2017-04-01

    The Tsimane Health and Life History Project, an integrated bio-behavioral study of the human life course, is designed to test competing hypotheses of human life-history evolution. One aim is to understand the bidirectional connections between life history and social behavior in a high-fertility, kin-based context lacking amenities of modern urban life (e.g. sanitation, banks, electricity). Another aim is to understand how a high pathogen burden influences health and well-being during development and adulthood. A third aim addresses how modernization shapes human life histories and sociality. Here we outline the project's goals, history, and main findings since its inception in 2002. We reflect on the implications of current findings and highlight the need for more coordinated ethnographic and biomedical study of contemporary nonindustrial populations to address broad questions that can situate evolutionary anthropology in a key position within the social and life sciences. © 2017 The Authors Evolutionary Anthropology: Issues, News, and Reviews Published by Wiley Periodicals, Inc.

  4. Psychological needs, purpose in life, and problem video game playing among Chinese young adults.

    Science.gov (United States)

    Wu, Anise M S; Lei, Lamis L M; Ku, Lisbeth

    2013-01-01

    The negative impacts of excessive and problematic video game playing on both children and adults are attracting increasing concern. Based on self-determination theory (SDT; Ryan & Deci, 2000), this study hypothesized that the three basic psychological needs of autonomy, competence, and relatedness are positively associated with purpose in life, which in turn acts as a protective factor against problem video game playing among Chinese young adult players. Through a questionnaire survey with a sample of 165 Chinese adults aged between 18 and 30 years (mean age = 22.7 years), we found that perceived autonomy, competence, relatedness, and purpose in life were all negatively correlated with problem game playing. The demographic and psychological factors explained 38% of the variances of problem game playing. Specifically, gender, perceived relatedness, and purpose in life emerged as the three most salient predictors of problem game playing among the Chinese young adults. The mediating role of purpose in life was evidenced and it was found that purpose in life mediated the influences of the psychological needs proposed by SDT on problem game playing. Moreover, young men were significantly more susceptible to problem game playing than their female counterparts. To conclude, psychological needs and purpose in life influenced Chinese young adults' vulnerability to problem game playing directly or indirectly. Intervention programs that encourage social involvement and voluntary work, as well as counseling service that helps clients to search for life purpose, are suggested for intervening in problem game playing among Chinese young adults.

  5. Pathways from fertility history to later life health: Results from analyses of the English Longitudinal Study of Ageing

    Directory of Open Access Journals (Sweden)

    Emily Grundy

    2015-01-01

    Full Text Available Background: Previous research shows associations between fertility histories and later life health. The childless, those with large families, and those with a young age at entry to parenthood generally have higher mortality and worse health than parents of two or three children. These associations are hypothesised to reflect a range of biosocial influences, but underlying mechanisms are poorly understood. Objective: To identify pathways from fertility histories to later life health by examining mediation through health-related behaviours, social support and strain, and wealth. Additionally to examine mediation through allostatic load - an indicator of multisystem physical dysregulation, hypothesised to be an outcome of chronic stress. Methods: Associations between fertility histories, mediators, and outcomes were analysed using path models. Data were drawn from the English Longitudinal Study of Ageing. Outcomes studied were a measure of allostatic load based on 9 biomarkers and self-reported long-term illness which limited activities. Results: Early parenthood (Conclusions: In England early parenthood and larger family size are associated with less wealth and poorer health behaviours and this accounts for much of the association with health. At least part of this operates through stress-related physiological dysfunction (allostatic load.

  6. Health-related quality of life of young women with breast cancer. Review of the literature.

    Science.gov (United States)

    Yfantis, Aris; Intas, George; Tolia, Maria; Nikolaou, Michail; Tsoukalas, Nikolaos; Lymperi, Maria; Kyrgias, George; Zografos, George; Kontos, Michalis

    2018-01-01

    The purpose of the present article was to investigate the health related quality of life (QoL) of young women with breast cancer. For the purposes of this article, we reviewed the literature via the electronic databases Pubmed, Scopus and Google Scholar. Key words used were breast cancer, young women, health related quality of life, and quality of life. Young women reported fatigue, pain in the breast and hand problems with lymphedema as the most frequent physical effects of treatment. Other physical problems were the not periodic and painful menses, vaginal dryness and loss of libido. Many young women had depressive symptoms such as depressed mood, helplessness, hopelessness, sleep loss, psychomotor retardation and disorders of appetite. There were often concerns about the health monitoring and self-image, while they were anxious if they will have a baby in the future or if they can nurture the existing ones. Many problems arose in the career of young women. They faced discrimination in the labor supply and/or layoff because they were considered unable to do their job effectively. In addition, they reported isolation problems and feeling different from other women of similar age. Young women consider that their healthrelated QoL is worse compared with older women. Young women worry about their future, with particular reference to their role as mothers and especially to children-bearing. The free screening and non-exclusion of young women is particularly important for breast cancer prevention and women's well-being.

  7. Using Age-Based Life History Data to Investigate the Life Cycle and Vulnerability of Octopus cyanea

    Science.gov (United States)

    Herwig, Jade N.; Depczynski, Martial; Roberts, John D.; Semmens, Jayson M.; Gagliano, Monica; Heyward, Andrew J.

    2012-01-01

    Octopus cyanea is taken as an unregulated, recreationally fished species from the intertidal reefs of Ningaloo, Western Australia. Yet despite its exploitation and importance in many artisanal fisheries throughout the world, little is known about its life history, ecology and vulnerability. We used stylet increment analysis to age a wild O. cyanea population for the first time and gonad histology to examine their reproductive characteristics. O. cyanea conforms to many cephalopod life history generalisations having rapid, non-asymptotic growth, a short life-span and high levels of mortality. Males were found to mature at much younger ages and sizes than females with reproductive activity concentrated in the spring and summer months. The female dominated sex-ratios in association with female brooding behaviours also suggest that larger conspicuous females may be more prone to capture and suggests that this intertidal octopus population has the potential to be negatively impacted in an unregulated fishery. Size at age and maturity comparisons between our temperate bordering population and lower latitude Tanzanian and Hawaiian populations indicated stark differences in growth rates that correlate with water temperatures. The variability in life history traits between global populations suggests that management of O. cyanea populations should be tailored to each unique set of life history characteristics and that stylet increment analysis may provide the integrity needed to accurately assess this. PMID:22912898

  8. Analysis of Life Histories: A State Space Approach

    Directory of Open Access Journals (Sweden)

    Rajulton, Fernando

    2001-01-01

    Full Text Available EnglishThe computer package LIFEHIST written by the author, is meant for analyzinglife histories through a state-space approach. Basic ideas on which the various programs have beenbuilt are described in this paper in a non-mathematical language. Users can use various programs formultistate analyses based on Markov and semi-Markov frameworks and sequences of transitions implied inlife histories. The package is under constant revision and programs for using a few specific modelsthe author thinks will be useful for analyzing longitudinal data will be incorporated in the nearfuture.FrenchLe système d'ordinateur LIFEHIST écrit par l'auteur est établi pour analyser desévénements au cours de la vie par une approche qui tient compte des états aucours du temps. Les idées fondamentales à la base des divers programmes dumodule sont décrites dans un langage non-mathématique. Le systèmeLIFEHIST peut être utilisé pour des analyses Markov et semi-Markov desséquences d’événements au cours de la vie. Le module est sous révisionconstante, et des programmes que l’auteur compte ajouter pour l'usage dedonnées longitudinales sont décrit.

  9. Mammalian life histories: their evolution and molecular-genetic mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Sacher, G.A.

    1978-01-01

    Survival curves for various species of mammals are discussed and a table is presented to show recorded maximum life spans of about 30 species of mammals. The range of longevities is from one year for shrews and moles up to more than 80 years for the fin whale. The constitutional correlates of longevity are discussed with regard to body size, brain weight,metabolic rates, and body temperature. It is concluded that longevity evolved as a positive trait, associated with the evolution of large body size and brain size. Life table data for man, the thorough-bred horse, beagle dogs, and the laboratory rodents, Mus musculus and Peromyscus leucopus are discussed. The data show a pattern of exponential increase of death rate with age. A laboratory model using Mus musculus and Peromyscus leucopus for the study of the longevity-assurance mechanisms is described. (HLW)

  10. Life history strategies and biomass allocation : the population dynamics of perennial plants in a regional perspective

    NARCIS (Netherlands)

    Jongejans, E.

    2004-01-01

    This study aims to contribute to the knowledge of how plants respond to adverse influences of intensified land use. In particular, attention was paid to the ways in which life history strategies change in order to buffer environmental variation, and which important parts of the life cycle are

  11. Debkiss or the quest for the simplest generic model of animal life history.

    NARCIS (Netherlands)

    Jager, T.; Martin, B.T.; Zimmer, E.I.

    2013-01-01

    Understanding the life cycle of individual animals, and how it responds to stress, requires a model that causally links life-history traits (feeding, growth, development and reproduction). Dynamic Energy Budget (DEB) theory offers a powerful and formalised framework for building process-based models

  12. Road–side herbaceous vegetation: life history groups and habitat preferences

    Czech Academy of Sciences Publication Activity Database

    Šerá, Božena

    2010-01-01

    Roč. 58, č. 1 (2010), s. 69-79 ISSN 1505-2249 R&D Projects: GA MŠk(CZ) OC 350.002 Institutional research plan: CEZ:AV0Z60870520 Keywords : road-side vegetation * road ecology * life form * life history * habitat preference * alien species Subject RIV: EH - Ecology, Behaviour Impact factor: 0.542, year: 2010

  13. Fast–slow continuum and reproductive strategies structure plant life-history variation worldwide

    NARCIS (Netherlands)

    Salguero-Gómez, Roberto; Jones, Owen R.; Jongejans, Eelke; Blomberg, Simon; Hodgson, D.; Zuidema, P.A.; Kroon, de Hans; Buckley, Yvonne M.

    2016-01-01

    The identification of patterns in life-history strategies across the tree of life is essential to our prediction of population persistence, extinction, and diversification. Plants exhibit a wide range of patterns of longevity, growth, and reproduction, but the general determinants of this enormous

  14. Hope Amidst Hopelessness: Life Histories of Illiterate Oraon Tribal Women in Jharkhand, India

    Science.gov (United States)

    Minz, Nijhar Jharia

    2012-01-01

    This interpretive study asked the question: "What education and literacy insights can be gained from the studies of the life stories of illiterate Oraon women in Jharkhand, India?" Life history methodology was used to gain insights into the lived experiences of illiterate women. I hoped to provide meaning and give voice to the voiceless.…

  15. Cross-cultural Comparison of Learning in Human Hunting : Implications for Life History Evolution.

    Science.gov (United States)

    MacDonald, Katharine

    2007-12-01

    This paper is a cross-cultural examination of the development of hunting skills and the implications for the debate on the role of learning in the evolution of human life history patterns. While life history theory has proven to be a powerful tool for understanding the evolution of the human life course, other schools, such as cultural transmission and social learning theory, also provide theoretical insights. These disparate theories are reviewed, and alternative and exclusive predictions are identified. This study of cross-cultural regularities in how children learn hunting skills, based on the ethnographic literature on traditional hunters, complements existing empirical work and highlights future areas for investigation.

  16. Reading to young children : A head-start in life?

    NARCIS (Netherlands)

    Kalb, G.; van Ours, J.C.

    This paper investigates the importance of parents reading to their young children. Using Australian data we find that parental reading to children at age 4–5 has positive and significant effects on reading skills and cognitive skills (including numeracy skills) of these children at least up to age

  17. Reading to Young Children : A Head-Start in Life?

    NARCIS (Netherlands)

    Kalb, G.; van Ours, J.C.

    2013-01-01

    Abstract: This paper investigates the importance of parents reading to their young children. Using Australian data we find that parental reading to children at age 4 to 5 has positive and significant effects on reading skills and cognitive skills of these children at least up to age 10 or 11. Our

  18. Spotlighting a Silent Category of Young Females: The Life Experiences of "House Girls" in Turkey

    Science.gov (United States)

    Celik, Kezban; Lukuslu, Demet

    2012-01-01

    This article examines the everyday life experiences of young women in Turkey known as "ev kizi" or "house girls." The article explores how traditional gender roles and family structure in Turkish society limit their full participation in political, economic, and public life. The study is based on in-depth interviews conducted…

  19. Love, life and happiness: a study of partner relationships and well-being in young adulthood

    NARCIS (Netherlands)

    Soons, J.P.M.

    2009-01-01

    Love, life and happiness are the key elements of this dissertation. The long-term development of happiness, or more precisely, subjective well-being, and its determinants are studied in a young adult sample. That is where "life" comes in. When crossing the bridge from childhood to adulthood, people

  20. Serious, Violent Young Offenders in South Africa : Are They Life-Course Persistent Offenders?

    NARCIS (Netherlands)

    Souverein, F.A.; Ward, C.L.; Visser, I.; Burton, P.

    2016-01-01

    Life-course persistent offending contributes greatly to violent offending in any country. South Africa has high rates of violence; this study investigated what proportion of young South African offenders might be identified as life-course persistent, and what risk factors identified this group.

  1. Effects of maternal history of depression and early life maltreatment on children's health-related quality of life.

    Science.gov (United States)

    Dittrich, Katja; Fuchs, Anna; Bermpohl, Felix; Meyer, Justus; Führer, Daniel; Reichl, Corinna; Reck, Corinna; Kluczniok, Dorothea; Kaess, Michael; Hindi Attar, Catherine; Möhler, Eva; Bierbaum, Anna-Lena; Zietlow, Anna-Lena; Jaite, Charlotte; Winter, Sibylle Maria; Herpertz, Sabine C; Brunner, Romuald; Bödeker, Katja; Resch, Franz

    2018-01-01

    There is a well-established link between maternal depression and child mental health. Similar effects have been found for maternal history of early life maltreatment (ELM). However, studies investigating the relationship of children's quality of life and maternal depression are scarce and none have been conducted for the association with maternal ELM. The aim of the present study was to investigate the effects of maternal history of ELM and depression on children's health-related quality of life and to identify mediating factors accounting for these effects. Our study involved 194 mothers with and without history of depression and/or ELM and their children between five and 12 years. Children's health-related quality of life was assessed by maternal proxy- and child self-ratings using the KIDSCREEN. We considered maternal sensitivity and maternal parenting stress as potential mediators. We found an effect of maternal history of depression but not of maternal history of ELM on health-related quality of life. Maternal stress and sensitivity mediated the effects of maternal depression on child global health-related quality of life, as well as on the dimensions Autonomy & Parent Relation, School Environment (maternal and child rating), and Physical Wellbeing (child rating). Due to the cross-sectional design of the study, causal interpretations must be made with caution. Some scales yielded low internal consistency. Maternal impairments in areas of parenting which possibly developed during acute depression persist even after remission of acute affective symptoms. Interventions should target parenting stress and sensitivity in parents with prior depression. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Connecting proximate mechanisms and evolutionary patterns: pituitary gland size and mammalian life history.

    Science.gov (United States)

    Kamilar, J M; Tecot, S R

    2015-11-01

    At the proximate level, hormones are known to play a critical role in influencing the life history of mammals, including humans. The pituitary gland is directly responsible for producing several hormones, including those related to growth and reproduction. Although we have a basic understanding of how hormones affect life history characteristics, we still have little knowledge of this relationship in an evolutionary context. We used data from 129 mammal species representing 14 orders to investigate the relationship between pituitary gland size and life history variation. Because pituitary gland size should be related to hormone production and action, we predicted that species with relatively large pituitaries should be associated with fast life histories, especially increased foetal and post-natal growth rates. Phylogenetic analyses revealed that total pituitary size and the size of the anterior lobe of the pituitary significantly predicted a life history axis that was correlated with several traits including body mass, and foetal and post-natal growth rates. Additional models directly examining the association between relative pituitary size and growth rates produced concordant results. We also found that relative pituitary size variation across mammals was best explained by an Ornstein-Uhlenbeck model of evolution, suggesting an important role of stabilizing selection. Our results support the idea that the size of the pituitary is linked to life history variation through evolutionary time. This pattern is likely due to mediating hormone levels but additional work is needed. We suggest that future investigations incorporating endocrine gland size may be critical for understanding life history evolution. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

  3. Assessing the quality of life history information in publicly available databases.

    Science.gov (United States)

    Thorson, James T; Cope, Jason M; Patrick, Wesley S

    2014-01-01

    Single-species life history parameters are central to ecological research and management, including the fields of macro-ecology, fisheries science, and ecosystem modeling. However, there has been little independent evaluation of the precision and accuracy of the life history values in global and publicly available databases. We therefore develop a novel method based on a Bayesian errors-in-variables model that compares database entries with estimates from local experts, and we illustrate this process by assessing the accuracy and precision of entries in FishBase, one of the largest and oldest life history databases. This model distinguishes biases among seven life history parameters, two types of information available in FishBase (i.e., published values and those estimated from other parameters), and two taxa (i.e., bony and cartilaginous fishes) relative to values from regional experts in the United States, while accounting for additional variance caused by sex- and region-specific life history traits. For published values in FishBase, the model identifies a small positive bias in natural mortality and negative bias in maximum age, perhaps caused by unacknowledged mortality caused by fishing. For life history values calculated by FishBase, the model identified large and inconsistent biases. The model also demonstrates greatest precision for body size parameters, decreased precision for values derived from geographically distant populations, and greatest between-sex differences in age at maturity. We recommend that our bias and precision estimates be used in future errors-in-variables models as a prior on measurement errors. This approach is broadly applicable to global databases of life history traits and, if used, will encourage further development and improvements in these databases.

  4. Linking habitat structure to life history strategy: Insights from a Mediterranean killifish

    Science.gov (United States)

    Cavraro, Francesco; Daouti, Irini; Leonardos, Ioannis; Torricelli, Patrizia; Malavasi, Stefano

    2014-01-01

    Modern theories of life history evolution deal with finding links between environmental factors, demographic structure of animal populations and the optimal life history strategy. Small-sized teleost fish, occurring in fragmented populations under contrasting environments, have been widely used as study models to investigate these issues. In the present study, the Mediterranean killifish Aphanius fasciatus was used to investigate the relationships between some habitat features and life history strategy. We selected four sites in the Venice lagoon inhabited by this species, exhibiting different combinations of two factors: overall adult mortality, related to intertidal water coverage and a consequent higher level of predator exposure, and the level of sediment organic matter, as indicator of habitat trophic richness. Results showed that these were the two most important factors influencing demography and life history traits in the four sites. Fish from salt marshes with high predator pressure were smaller and produced a higher number of eggs, whereas bigger fish and a lower reproductive investment were found in the two closed, not tidally influenced habitats. Habitat richness was positively related with population density, but negatively related with growth rate. In particular the synergy between high resources and low predation level was found to be important in shaping peculiar life history traits. Results were discussed in the light of the interactions between selective demographic forces acting differentially on age/size classes, such as predation, and habitat trophic richness that may represent an important energetic constraint on life history traits. The importance to link habitat productivity and morphology to demographic factors for a better understanding of the evolution of life history strategy under contrasting environments was finally suggested.

  5. The start of life: a history of obstetrics.

    Science.gov (United States)

    Drife, J

    2002-05-01

    Obstetric intervention originally consisted of extraction of the baby, usually by the breech, to save the mother's life in obstructed labour. Forceps, introduced in the 17th century, were later refined by men-midwives like William Smellie. In Victorian times, Simpson championed chloroform anaesthesia, Lister pioneered antisepsis, and caesarean section was introduced. In 1935, however, Britain's maternal mortality rate was still around 400/100,000. It fell dramatically after antibiotics appeared and is now 11.4. In the 1960s ultrasound and electronic fetal monitoring became widely used. In 2000 the British caesarean section rate reached 20%. Worldwide, childbirth still causes 600,000 maternal deaths a year.

  6. Health related quality of life in Dutch young adults: psychometric properties of the PedsQL generic core scales young adult version

    NARCIS (Netherlands)

    Limperg, Perrine F.; Haverman, Lotte; van Oers, Hedy A.; van Rossum, Marion A. J.; Maurice-Stam, Heleen; Grootenhuis, Martha A.

    2014-01-01

    The purpose of this study is to provide Dutch norm data and to assess internal consistency and construct validity for the Pediatric Quality of Life Inventory Young Adult Generic Core Scales (PedsQL_YA) in Dutch young adults aged 18-30 years. A sample of 649 young adults from the general Dutch

  7. Mercury Exposure in Young Adulthood and Incidence of Diabetes Later in Life

    Science.gov (United States)

    He, Ka; Xun, Pengcheng; Liu, Kiang; Morris, Steve; Reis, Jared; Guallar, Eliseo

    2013-01-01

    OBJECTIVE Laboratory studies suggest that exposure to methylmercury at a level similar to those found in fish may induce pancreatic islet β-cell dysfunction. Few, if any, human studies have examined the association between mercury exposure and diabetes incidence. We examined whether toenail mercury levels are associated with incidence of diabetes in a large prospective cohort. RESEACH DESIGN AND METHODS A prospective cohort of 3,875 American young adults, aged 20–32 years, free of diabetes in 1987 (baseline), were enrolled and followed six times until 2005. Baseline toenail mercury levels were measured with instrumental neutron-activation analysis. Incident diabetes was identified by plasma glucose levels, oral glucose tolerance tests, hemoglobin A1C levels, and/or antidiabetes medications. RESULTS A total of 288 incident cases of diabetes occurred over 18 years of follow-up. In multivariate analyses adjusted for age, sex, ethnicity, study center, education, smoking status, alcohol consumption, physical activity, family history of diabetes, intakes of long-chain n-3 fatty acids and magnesium, and toenail selenium, toenail mercury levels were positively associated with the incidence of diabetes. The hazard ratio (95% CI) of incident diabetes compared the highest to the lowest quintiles of mercury exposure was 1.65 (1.07–2.56; P for trend = 0.02). Higher mercury exposure at baseline was also significantly associated with decreased homeostasis model assessment of β-cell function index (P for trend mercury exposure in young adulthood may have elevated risk of diabetes later in life. PMID:23423697

  8. Quality of life in adolescents and young adults with CHD is not reduced

    DEFF Research Database (Denmark)

    Schrøder, Morten; Boisen, Kirsten A.; Reimers, Jesper

    2016-01-01

    We performed a systematic review and meta-analysis of observational studies assessing quality of life in adolescents and young adults born with CHD compared with age-matched controls. We carried out a systematic search of the literature published in Medline, Embase, PsychINFO, and the Cochrane....... The studies were of acceptable-to-good quality. The meta-analysis of six studies on quality of life showed no significant difference – mean difference: −1.31; 95% confidence intervals: −6.51 to +3.89, I2=90.9% – between adolescents and young adults with CHD and controls. Similar results were found in 10...... studies not eligible for the meta-analysis. In subdomains, it seems that patients had reduced physical quality of life; however, social functioning was comparable or better compared with controls. For the first time in a meta-analysis, we have shown that quality of life in adolescents and young adults...

  9. SATISFACTION WITH LIFE AMONG YOUNG ADULTS IN FOUR ARAB COUNTRIES.

    Science.gov (United States)

    Abdel-Khalek, Ahmed M; El Nayal, Mayssah A

    2015-12-01

    This study sought to explore the sex and cultural differences in satisfaction with life between undergraduate men and women recruited from four Arab countries, i.e., Egypt, Kuwait, Lebanon, and Qatar (N = 1,322); ages ranged from 18 to 27 years. The participants responded to the Arabic version of the Satisfaction with Life Scale. Egyptian and Lebanese women obtained significantly higher mean scores on satisfaction with life than did their male counterparts, whereas there were no significant sex differences in the Kuwaiti and Qatari samples. For men, the Qatari and Kuwaiti samples obtained the high mean scores on satisfaction with life, whereas the Egyptian and Lebanese samples obtained the low mean scores. For women, the Qatari sample had the higher mean score, whereas the Egyptian sample obtained the lowest mean score. The results were explained in light of the positive association between gross domestic product and satisfaction with life.

  10. Stressful life events and depressive symptoms in mothers and fathers of young children.

    Science.gov (United States)

    Flouri, Eirini; Narayanan, Martina K; Nærde, Ane

    2018-04-01

    Parents of young children generally report more depressive symptoms than parents of adult children or people without children, mainly because the presence of young children increases exposure to significant stressors (such as stressful life events). However, most studies on the depressogenic role of stressful life events in parents of young children have focussed on mothers. Using data from 1138 families with young children in Norway, we investigated gender differences in the effect of stressful life events after a child's birth on the development of parental depressive symptoms in 3 follow-ups at child's ages 3-6 years. We also explored if gender differences in disposition (personality) may explain any gender differences in the depressogenic effect of life events. Nesting parents within families, we found a female gender bias for both neuroticism and depressive symptoms but no gender difference in the number of life events reported. Importantly, the number of stressful life events predicted the level and course of depressive symptoms similarly for mothers and fathers. Personality traits did not change the association between stressful life events and depressive symptoms in either mothers or fathers. Given the study design, causality cannot be inferred. There was no gender difference in the depressogenic effect of stressful life events in our sample. There was no evidence for a female dispositional sensitivity to the depressogenic effect of stressful life events, either. Stressful life events put both mothers and fathers of young children at risk of depression. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

  11. Life lines: An art history of biological research around 1800.

    Science.gov (United States)

    Bruhn, Matthias

    2011-12-01

    Around 1800, the scientific "illustrator" emerged as a new artistic profession in Europe. Artists were increasingly sought after in order to picture anatomical dissections and microscopic observations and to translate drawings into artworks for books and journals. By training and technical expertise, they introduced a particular kind of knowledge into scientific perception that also shaped the common image of nature. Illustrations of scientific publications, often undervalued as a biased interpretation of facts and subordinate to logic and description, thus convey an 'art history' of science in its own right, relevant both for the understanding of biological thought around 1800 as well as for the development of the arts and their historiography. The article is based on an analysis of botanical treatises produced for the Göttingen Society of Sciences in 1803, during an early phase of microscopic cell research, in order to determine the constitutive role of artistic knowledge and the media employed for the visualization and conceptualization of biological issues. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Internal Migration and Life Satisfaction: Well-Being Effects of Moving as a Young Adult

    OpenAIRE

    Switek, Malgorzata

    2012-01-01

    Migration typically leads to higher income, but its association with life satisfaction remains unclear. Is migration accompanied by an increase in life satisfaction? If it is, is the increase in income responsible or are other life domains driving the satisfaction changes? These two questions are addressed using longitudinal data from a Swedish Young Adult Panel Study for 1999 and 2009. Comparing migrants to non-migrants, it is found that internal migration is accompanied by an increase in li...

  13. The reminiscence bump reconsidered: children's prospective life stories show a bump in young adulthood.

    Science.gov (United States)

    Bohn, Annette; Berntsen, Dorthe

    2011-02-01

    The reminiscence bump-the reporting of more memories from young adulthood than from other stages of life-is considered a hallmark of autobiographical memory research. The most prevalent explanations for this effect assume that events in young adulthood are favored because of the way they are encoded and maintained in long-term memory. Here we show that a similar increase of events in early adulthood is found when children narrate their personal futures. In Study 1, children wrote their future life stories. The events in these life stories were mostly life-script events, and their distribution showed a clear bump in young adulthood. In Study 2, children were prompted by word cues to write down events from their future lives. The events generated consisted mostly of non-life-script events, and those events did not show a bump in young adulthood. Our findings challenge prevailing explanations of the reminiscence bump and suggest that the cultural life script forms an overarching organizational principle for autobiographical memories and future representations across the life span.

  14. Molecular phylogenetics of the genus Neoconocephalus (orthoptera, tettigoniidae and the evolution of temperate life histories.

    Directory of Open Access Journals (Sweden)

    Robert L Snyder

    Full Text Available BACKGROUND: The katydid genus Neoconocephalus (25+ species has a prominent acoustic communication system and occurs in large parts of the Neotropics and Nearctic. This group has been subject of numerous behavioral, physiological, and evolutionary studies of its acoustic communication system. Two distinct life histories occur in this group: The tropical life history incorporates multiple generations/year and direct egg development without environmental triggers. Temperate life history is characterized by overwintering in the egg stage, cold trigger of egg development, and one generation/year. This study reconstructs the phylogenetic relationships within the genus to (1 determine the evolutionary history of the temperate life history, and (2 to support comparative studies of evolutionary and physiological problems in this genus. METHODOLOGY/PRINCIPAL FINDINGS: We used Amplified Fragment Length Polymorphisms (AFLP, and sequences of two nuclear loci and one mitochondrial locus to reconstruct phylogenetic relationships. The analysis included 17 ingroup and two outgroup species. AFLP and mitochondrial data provided resolution at the species level while the two nuclear loci revealed only deeper nodes. The data sets were combined in a super-matrix to estimate a total evidence tree. Seven of the temperate species form a monophyletic group; however, three more temperate species were placed as siblings of tropical species. CONCLUSIONS/SIGNIFICANCE: Our analyses support the reliability of the current taxonomic treatment of the Neoconocephalus fauna of Caribbean, Central, and North America. Ancestral state reconstruction of life history traits was not conclusive, however at least four transitions between life histories occurred among our sample of species. The proposed phylogeny will strengthen conclusions from comparative work in this group.

  15. The origin of parental care in relation to male and female life history.

    Science.gov (United States)

    Klug, Hope; Bonsall, Michael B; Alonzo, Suzanne H

    2013-04-01

    The evolution of maternal, paternal, and bi-parental care has been the focus of a great deal of research. Males and females vary in basic life-history characteristics (e.g., stage-specific mortality, maturation) in ways that are unrelated to parental investment. Surprisingly, few studies have examined the effect of this variation in male and female life history on the evolution of care. Here, we use a theoretical approach to determine the sex-specific life-history characteristics that give rise to the origin of paternal, maternal, or bi-parental care from an ancestral state of no care. Females initially invest more into each egg than males. Despite this inherent difference between the sexes, paternal, maternal, and bi-parental care are equally likely when males and females are otherwise similar. Thus, sex differences in initial zygotic investment do not explain the origin of one pattern of care over another. However, sex differences in adult mortality, egg maturation rate, and juvenile survival affect the pattern of care that will be most likely to evolve. Maternal care is more likely if female adult mortality is high, whereas paternal care is more likely if male adult mortality is high. These findings suggest that basic life-history differences between the sexes can alone explain the origin of maternal, paternal, and bi-parental care. As a result, the influence of life-history characteristics should be considered as a baseline scenario in studies examining the origin of care.

  16. Contrasting latitudinal patterns of life-history divergence in two genera of new world thrushes (Turdinae)

    Science.gov (United States)

    Boyce, Andy J.; Martin, Thomas E.

    2017-01-01

    Several long-standing hypotheses have been proposed to explain latitudinal patterns of life-history strategies. Here, we test predictions of four such hypotheses (seasonality, food limitation, nest predation and adult survival probability) by examining life-history traits and age-specific mortality rates of several species of thrushes (Turdinae) based on field studies at temperate and tropical sites and data gathered from the literature. Thrushes in the genus Catharus showed the typical pattern of slower life-history strategies in the tropics while co-occuring Turdus thrushes differed much less across latitudes. Seasonality is a broadly accepted hypothesis for latitudinal patterns, but the lack of concordance in latitudinal patterns between co-existing genera that experience the same seasonal patterns suggests seasonality cannot fully explain latitudinal trait variation in thrushes. Nest-predation also could not explain patterns based on our field data and literature data for these two genera. Total feeding rates were similar, and per-nestling feeding rates were higher at tropical latitudes in both genera, suggesting food limitation does not explain trait differences in thrushes. Latitudinal patterns of life histories in these two genera were closely associated with adult survival probability. Thus, our data suggest that environmental influences on adult survival probability may play a particularly strong role in shaping latitudinal patterns of life-history traits.

  17. Seed after-ripening and dormancy determine adult life history independently of germination timing.

    Science.gov (United States)

    de Casas, Rafael Rubio; Kovach, Katherine; Dittmar, Emily; Barua, Deepak; Barco, Brenden; Donohue, Kathleen

    2012-05-01

    • Seed dormancy can affect life history through its effects on germination time. Here, we investigate its influence on life history beyond the timing of germination. • We used the response of Arabidopsis thaliana to chilling at the germination and flowering stages to test the following: how seed dormancy affects germination responses to the environment; whether variation in dormancy affects adult phenology independently of germination time; and whether environmental cues experienced by dormant seeds have an effect on adult life history. • Dormancy conditioned the germination response to low temperatures, such that prolonged periods of chilling induced dormancy in nondormant seeds, but stimulated germination in dormant seeds. The alleviation of dormancy through after-ripening was associated with earlier flowering, independent of germination date. Experimental dormancy manipulations showed that prolonged chilling at the seed stage always induced earlier flowering, regardless of seed dormancy. Surprisingly, this effect of seed chilling on flowering time was observed even when low temperatures did not induce germination. • In summary, seed dormancy influences flowering time and hence life history independent of its effects on germination timing. We conclude that the seed stage has a pronounced effect on life history, the influence of which goes well beyond the timing of germination. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

  18. Switch between life history strategies due to changes in glycolytic enzyme gene dosage in Saccharomyces cerevisiae.

    Science.gov (United States)

    Wang, Shaoxiao; Spor, Aymé; Nidelet, Thibault; Montalent, Pierre; Dillmann, Christine; de Vienne, Dominique; Sicard, Delphine

    2011-01-01

    Adaptation is the process whereby a population or species becomes better fitted to its habitat through modifications of various life history traits which can be positively or negatively correlated. The molecular factors underlying these covariations remain to be elucidated. Using Saccharomyces cerevisiae as a model system, we have investigated the effects on life history traits of varying the dosage of genes involved in the transformation of resources into energy. Changing gene dosage for each of three glycolytic enzyme genes (hexokinase 2, phosphoglucose isomerase, and fructose-1,6-bisphosphate aldolase) resulted in variation in enzyme activities, glucose consumption rate, and life history traits (growth rate, carrying capacity, and cell size). However, the range of effects depended on which enzyme was expressed differently. Most interestingly, these changes revealed a genetic trade-off between carrying capacity and cell size, supporting the discovery of two extreme life history strategies already described in yeast populations: the "ants," which have lower glycolytic gene dosage, take up glucose slowly, and have a small cell size but reach a high carrying capacity, and the "grasshoppers," which have higher glycolytic gene dosage, consume glucose more rapidly, and allocate it to a larger cell size but reach a lower carrying capacity. These results demonstrate antagonist pleiotropy for glycolytic genes and show that altered dosage of a single gene drives a switch between two life history strategies in yeast.

  19. Life history plasticity of a tropical seabird in response to El Niño anomalies during early life.

    Directory of Open Access Journals (Sweden)

    Sergio Ancona

    Full Text Available Food shortage and other challenges associated with El Niño Southern Oscillation (ENSO experienced early in life may have long-term impacts on life history traits, but these potential impacts remain virtually unexplored. By monitoring 2556 blue-footed boobies from 11 cohorts, we showed that birds facing warm water ENSO conditions (and probably low food availability in the natal year were underweight at fledging, recruited earlier and bred less frequently, but showed no deficit in longevity or breeding success over the first 10 years. Life history impacts of ENSO were substantial when experienced in the prenatal year, the natal year, or the second year of life, and absent when experienced in the third year of life, implying that harsh conditions have greater effects when experienced earlier in life. Sexual differences in impacts depended on the age when warm water conditions were experienced: pre-natal and natal experience, respectively, induced early recruitment and influenced the relationship between age and laying date only in females, whereas second year experience reduced total breeding success only of males. Most surprising were positive transgenerational impacts in females: daughters of females that experienced ENSO conditions in their natal year showed improved breeding success. Developmental plasticity of boobies thus enables them to largely neutralize potential long-term impacts of harsh climatic conditions experienced early in life.

  20. Life history plasticity of a tropical seabird in response to El Niño anomalies during early life.

    Science.gov (United States)

    Ancona, Sergio; Drummond, Hugh

    2013-01-01

    Food shortage and other challenges associated with El Niño Southern Oscillation (ENSO) experienced early in life may have long-term impacts on life history traits, but these potential impacts remain virtually unexplored. By monitoring 2556 blue-footed boobies from 11 cohorts, we showed that birds facing warm water ENSO conditions (and probably low food availability) in the natal year were underweight at fledging, recruited earlier and bred less frequently, but showed no deficit in longevity or breeding success over the first 10 years. Life history impacts of ENSO were substantial when experienced in the prenatal year, the natal year, or the second year of life, and absent when experienced in the third year of life, implying that harsh conditions have greater effects when experienced earlier in life. Sexual differences in impacts depended on the age when warm water conditions were experienced: pre-natal and natal experience, respectively, induced early recruitment and influenced the relationship between age and laying date only in females, whereas second year experience reduced total breeding success only of males. Most surprising were positive transgenerational impacts in females: daughters of females that experienced ENSO conditions in their natal year showed improved breeding success. Developmental plasticity of boobies thus enables them to largely neutralize potential long-term impacts of harsh climatic conditions experienced early in life.

  1. Young Pioneers: Cohabitation and Family Life Pathways in Denmark

    DEFF Research Database (Denmark)

    Loft, Lisbeth Trille Gylling

    2011-01-01

    logistic regression and latent class clusteranalysis to examine the likelihood of ever forming a cohabiting union, to situate cohabitation inthe larger context of family life pathways, and to explore social circumstances as well aspersonal aspirations as determinants of the identified family life pathways......Using a life course perspective, I examine cohabitation in a cohort of Danish women and menborn in 1954, whom formed families as cohabitation became normative in the Danish context. Inaddition, this cohort was among the first cohorts to come of age in a well-established Danishwelfare state, which...

  2. Life-history evolution and the microevolution of intermediary metabolism: activities of lipid-metabolizing enzymes in life-history morphs of a wing-dimorphic cricket.

    Science.gov (United States)

    Zera, Anthony J; Zhao, Zhangwu

    2003-03-01

    Although a considerable amount of information is available on the ecology, genetics, and physiology of life-history traits, much more limited data are available on the biochemical and genetic correlates of life-history variation within species. Specific activities of five enzymes of lipid biosynthesis and two enzymes of amino acid catabolism were compared among lines selected for flight-capable (LW[f]) versus flightless (SW) morphs of the cricket Gryllus firmus. These morphs, which exist in natural populations, differ genetically in ovarian growth (100-400% higher in SW) and aspects of flight capability including the size of wings and flight muscles, and the concentration of triglyceride flight fuel (40% greater in LW[f]). Consistently higher activity of each enzyme in LW(f) versus SW-selected lines, and strong co-segregation between morph and enzyme activity, demonstrated genetically based co-variance between wing morph and enzyme activity. Developmental profiles of enzyme activities strongly paralleled profiles of triglyceride accumulation during adulthood and previous measures of in vivo lipid biosynthesis. These data strongly imply that genetically based elevation in activities of lipogenic enzymes, and enzymes controlling the conversion of amino acids into lipids, is an important cause underlying the elevated accumulation of triglyceride in the LW(f) morph, a key biochemical component of the trade-off between elevated early fecundity and flight capability. Global changes in lipid and amino-acid metabolism appear to have resulted from microevolutionary alteration of regulators of metabolism. Finally, strong genotype x environment (diet) interactions were observed for most enzyme activities. Future progress in understanding the functional causes of life-history evolution requires a more detailed synthesis of the fields of life-history evolution and metabolic biochemistry. Wing polymorphism is a powerful experimental model in such integrative studies.

  3. Factors influencing young adults' attitudes and knowledge of late-life sexuality among older women.

    Science.gov (United States)

    Allen, Rebecca S; Petro, Kathryn N; Phillips, Laura L

    2009-03-01

    Although sexuality is valued throughout the lifespan, older women's sexual expression can be influenced by physical, mental and social factors, including attitudes and stereotypes held by younger generations. By gaining an understanding of what influences negative attitudes toward sexuality and beliefs about sexual consent capacity, the stigma associated with sexuality in late life may be reduced. Using vignette methodology in an online survey, we examined older women's health and young adults' (N = 606; mean age = 18.86, SD = 1.42, range 17-36) general knowledge and attitudes toward aging and sexuality, personal sexual behavior, religious beliefs and perceived closeness with an older adult on attitudes towards sexual behavior and perceptions of consent capacity among older women. The health status of older women proved important in determining young adults' acceptance and perception of sexual consent capacity regarding late-life heterosexual/autoerotic and homosexual behaviors. Specifically, young adults expressed lower acceptance and more doubt regarding capacity to consent to sexual expression when the older woman was described as cognitively impaired. Additionally, young adults' personal attitudes toward late-life sexuality, but not knowledge, predicted acceptance toward sexual expression and belief in sexual consent capacity. Attention toward the influence of older women's cognitive health and young adults' attitudes toward late-life sexuality may prove beneficial in designing interventions to decrease the stigma associated with sexual activity in later life.

  4. Fast-slow continuum and reproductive strategies structure plant life-history variation worldwide.

    Science.gov (United States)

    Salguero-Gómez, Roberto; Jones, Owen R; Jongejans, Eelke; Blomberg, Simon P; Hodgson, David J; Mbeau-Ache, Cyril; Zuidema, Pieter A; de Kroon, Hans; Buckley, Yvonne M

    2016-01-05

    The identification of patterns in life-history strategies across the tree of life is essential to our prediction of population persistence, extinction, and diversification. Plants exhibit a wide range of patterns of longevity, growth, and reproduction, but the general determinants of this enormous variation in life history are poorly understood. We use demographic data from 418 plant species in the wild, from annual herbs to supercentennial trees, to examine how growth form, habitat, and phylogenetic relationships structure plant life histories and to develop a framework to predict population performance. We show that 55% of the variation in plant life-history strategies is adequately characterized using two independent axes: the fast-slow continuum, including fast-growing, short-lived plant species at one end and slow-growing, long-lived species at the other, and a reproductive strategy axis, with highly reproductive, iteroparous species at one extreme and poorly reproductive, semelparous plants with frequent shrinkage at the other. Our findings remain consistent across major habitats and are minimally affected by plant growth form and phylogenetic ancestry, suggesting that the relative independence of the fast-slow and reproduction strategy axes is general in the plant kingdom. Our findings have similarities with how life-history strategies are structured in mammals, birds, and reptiles. The position of plant species populations in the 2D space produced by both axes predicts their rate of recovery from disturbances and population growth rate. This life-history framework may complement trait-based frameworks on leaf and wood economics; together these frameworks may allow prediction of responses of plants to anthropogenic disturbances and changing environments.

  5. Brief Self-Report Scales Assessing Life History Dimensions of Mating and Parenting Effort

    Directory of Open Access Journals (Sweden)

    Daniel J. Kruger

    2017-02-01

    Full Text Available Life history theory (LHT is a powerful evolutionary framework for understanding physiological, psychological, and behavioral variation both between and within species. Researchers and theorists are increasingly integrating LHT into evolutionary psychology, as it provides a strong foundation for research across many topical areas. Human life history variation has been represented in psychological and behavioral research in several ways, including indicators of conditions in the developmental environment, indicators of conditions in the current environment, and indicators of maturation and life milestones (e.g., menarche, initial sexual activity, first pregnancy, and in self-report survey scale measures. Survey scale measures have included constructs such as time perspective and future discounting, although the most widely used index is a constellation of indicators assessing the K-factor, thought to index general life history speed (from fast to slow. The current project examined the utility of two brief self-report survey measures assessing the life history dimensions of mating effort and parenting effort with a large undergraduate sample in the United States. Consistent with the theory, items reflected two inversely related dimensions. In regressions including the K-factor, the Mating Effort Scale proved to be a powerful predictor of other constructs and indicators related to life history variation. The Parenting Effort Scale had less predictive power overall, although it explained unique variance across several constructs and was the only unique predictor of the number of long-term (serious and committed relationships. These scales may be valuable additions to self-report survey research projects examining life history variation.

  6. The World of Barilla Taylor: Bringing History to Life through Primary Sources.

    Science.gov (United States)

    Stearns, Liza

    1997-01-01

    Presents a lesson plan using material from a primary source-based curriculum kit titled "The World of Barilla Taylor." The kit uses personal letters, maps, hospital and work records, and other primary sources to document the life of a young woman working in the textile mills in 19th-century Massachusetts. (MJP)

  7. The Genetic Architecture Underlying the Evolution of a Rare Piscivorous Life History Form in Brown Trout after Secondary Contact and Strong Introgression

    Directory of Open Access Journals (Sweden)

    Arne Jacobs

    2018-05-01

    Full Text Available Identifying the genetic basis underlying phenotypic divergence and reproductive isolation is a longstanding problem in evolutionary biology. Genetic signals of adaptation and reproductive isolation are often confounded by a wide range of factors, such as variation in demographic history or genomic features. Brown trout (Salmo trutta in the Loch Maree catchment, Scotland, exhibit reproductively isolated divergent life history morphs, including a rare piscivorous (ferox life history form displaying larger body size, greater longevity and delayed maturation compared to sympatric benthivorous brown trout. Using a dataset of 16,066 SNPs, we analyzed the evolutionary history and genetic architecture underlying this divergence. We found that ferox trout and benthivorous brown trout most likely evolved after recent secondary contact of two distinct glacial lineages, and identified 33 genomic outlier windows across the genome, of which several have most likely formed through selection. We further identified twelve candidate genes and biological pathways related to growth, development and immune response potentially underpinning the observed phenotypic differences. The identification of clear genomic signals divergent between life history phenotypes and potentially linked to reproductive isolation, through size assortative mating, as well as the identification of the underlying demographic history, highlights the power of genomic studies of young species pairs for understanding the factors shaping genetic differentiation.

  8. Life history correlates of inbreeding depression in mandrills (Mandrillus sphinx).

    Science.gov (United States)

    Charpentier, M; Setchell, J M; Prugnolle, F; Wickings, E J; Peignot, P; Balloux, F; Hossaert-McKey, M

    2006-01-01

    Inbreeding depression reflects the negative consequences of increased homozygosity at genes that affect fitness. We investigate inbreeding depression in a semi-free-ranging colony of mandrills (Mandrillus sphinx), using high-quality pedigree data, comprising five maternal generations and 20 years of morphological and demographic data. We examine the relationship between inbreeding coefficients and four fitness correlates: two growth parameters (mass and height for age) and longevity in both sexes, and age at first conception in females. Inbreeding was correlated with both growth parameters, but only in females, with inbred females being smaller than noninbred females. Inbreeding was also correlated significantly with age at first conception, with inbred females giving birth earlier in life than noninbred females. We suggest that sex-biased maternal investment may explain this sex-differential response to inbreeding, although the lack of a significant association between inbreeding and growth in males may also be due to the provisioned nature of the colony. The surprising relationship between age at first conception and inbreeding may be related to smaller adult size in inbred females, or to their being less able to escape from male sexual coercion.

  9. Early life history and habitat ecology of estuarine fishes: responses to natural and human induced change

    Directory of Open Access Journals (Sweden)

    Kenneth Able

    2015-12-01

    Full Text Available Our understanding of the early life history of fishes and their habitats has proceeded from basic natural history to ecology, but we often need to return to natural history to address deficiencies in conceptual and quantitative models of ecosystems. This understanding is further limited by the complex life history of fishes and the lack of appreciation of shifting baselines in estuaries. These inadequacies are especially evident when we try to address the effects of human influences, e.g. fishing, urbanization, and climate change. Often our baselines are inadequate or inaccurate. Our work has detected these along the coasts of the U.S. in extensive time series of larval fish ingress into estuaries, studies of the effects of urbanization, and responses to catastrophes such as the BP oil spill. Long-term monitoring, especially, continues to provide critical insights

  10. Acne Vulgaris and Quality of Life Among Young Adults in South India

    Science.gov (United States)

    Durai, Priya Cinna T; Nair, Dhanya G

    2015-01-01

    Acne vulgaris is a chronic condition affecting more than 85% of adolescents and young adults. It is one of the most common diseases affecting humanity and its impact on quality of life (QoL) is important. The impact of acne on QoL in Indian patients remains undocumented. The study was undertaken to detect the impact of acne vulgaris and related factors that may influence the QoL. Materials and Methods: This was a hospital-based, prospective, cross-sectional, prestructured, questionnaire-based study done on 140 consenting individuals, who attended the Dermatology outpatient department. Acne vulgaris was graded using simple grading system. QoL was measured using a combination of skin disease-specific (Dermatological Life Quality Index (DLQI)) and acne-specific (Cardiff Acne Disability Index (CADI)) questionnaires. Results: Majority of our study population were students (103, 73.6%). Face (139, 99.3%) was the commonest site of acne and comedones 133, 95% were the commonest type of lesion. Most of the individuals 66, 47.1% were observed to have grade 1 acne. The mean DLQI score was 6.91 and the mean CADI score was 5.2. Association between the scores was statistically significant. Age, occupation, marital status, family, and treatment history played a role in affecting the QoL. Diet, smoking, and alcohol did not influence the QoL. Conclusion: Though acne had impact on patient's QoL, it was less severe in our study. It is important for health professionals to incorporate QoL measurements when managing acne patients to provide better and appropriate care. PMID:25657394

  11. Evolution of boldness and life-history in response to selective harvesting

    DEFF Research Database (Denmark)

    Andersen, Ken Haste; Marty, Lise; Arlinghaus, Robert

    2018-01-01

    Whether intensive harvesting alters the behavioral repertoire of exploited fishes is currently unknown, but plausible. We extend a fish life-history model to account for boldness as a personality trait that affects foraging intensity, which affects energy intake and risk from predation and fishing...... gear. We systematically investigate life-history and behavioral trait evolution along the boldness–timidity axis in response to the full range of common selectivity and exploitation patterns in fisheries. In agreement with previous studies, we find that any type of harvesting selects for fast life...... histories and that merely elevated, yet unselective, fishing mortality favors boldness. We also find that timid-selective fishing (which can be expected in species targeted by active gear types) selects for increased boldness. By contrast, increased timidity is predicted when fishing targets bolder...

  12. Life history and status of shortnose sturgeon (Acipenser brevirostrum) in the Potomac River

    Science.gov (United States)

    Kieffer, Micah

    2009-01-01

    We collected the first life history information on shortnose sturgeon (Acipenser brevirostrum) in any of the rivers to Chesapeake Bay, the geographic center of the species range. In the Potomac River, two telemetry-tagged adult females used 124 km of river: a saltwater/freshwater reach at river km (rkm) 63-141 was the foraging-wintering concentration area, and one female migrated to spawn at rkm 187 in Washington, DC. The spawning migration explained the life history context of an adult captured 122 years ago in Washington, DC, supporting the idea that a natal population once lived in the river. Repeated homing migrations to foraging and wintering areas suggested the adults were residents, not transient coastal migrants. All habitats that adults need to complete life history are present in the river. The Potomac River shortnose sturgeon offers a rare opportunity to learn about the natural rebuilding of a sturgeon population.

  13. Religious People Are Trusted Because They Are Viewed as Slow Life-History Strategists.

    Science.gov (United States)

    Moon, Jordan W; Krems, Jaimie Arona; Cohen, Adam B

    2018-03-01

    Religious people are more trusted than nonreligious people. Although most theorists attribute these perceptions to the beliefs of religious targets, religious individuals also differ in behavioral ways that might cue trust. We examined whether perceivers might trust religious targets more because they heuristically associate religion with slow life-history strategies. In three experiments, we found that religious targets are viewed as slow life-history strategists and that these findings are not the result of a universally positive halo effect; that the effect of target religion on trust is significantly mediated by the target's life-history traits (i.e., perceived reproductive strategy); and that when perceivers have direct information about a target's reproductive strategy, their ratings of trust are driven primarily by his or her reproductive strategy, rather than religion. These effects operate over and above targets' belief in moralizing gods and offer a novel theoretical perspective on religion and trust.

  14. The Life History Calendar Method and Multilevel Modeling: Application to Research on Intimate Partner Violence.

    Science.gov (United States)

    Yoshihama, Mieko; Bybee, Deborah

    2011-03-01

    Intimate partner violence (IPV) is prevalent and often recurrent in women's lives. To better understand the changing risk of IPV over the life course, which could guide more effective policies and program responses, methodological innovations are needed. Life History Calendar methods enhance respondents' recall of the timing of specific types of IPV experienced over the life course. Multilevel modeling provides a way to analyze individual and collective trajectories and examine covariates of IPV risk. We apply these complementary methods to examine IPV trajectories for a sample of women of Filipina descent living in the United States, examining life course timing and cohort effects. © The Author(s) 2011.

  15. Life history of lake herring of Green Bay, Lake Michigan

    Science.gov (United States)

    Smith, Stanford H.

    1956-01-01

    Although the lake herring has been an important contributor to the commercial fish production of Green Bay, little has been known about it. This study is based on field observations and data from about 6,500 lake herring collected over the period 1948 to 1952. Relatively nonselective commercial pound nets were a primary source of material for the study of age and growth. Commercial and experimental gill nets were used to obtain data on gear selectivity and vertical distribution. Scales were employed to investigate age and growth. Age group IV normally dominated commercial catches during the first half of the calendar year and age group III the last half. At these ages the fish averaged about 10.5 inches in length. The season's growth started in May, was most rapid in July, and terminated near the end of October. The sexes grew at the same rate. Selectivity of fishing gear was found to influence the estimation of growth. Geographical and annual differences in growth are shown. Factors that might contribute to discrepancies in calculated growth are evaluated. Possible real and apparent causes of growth compensation are given. The relation between length and weight is shown to vary with sex, season, year, and method of capture. Females were relatively more plentiful in commercial catches in February than in May through December. The percentage of females decreased with increase in age in pound-net catches but increased with age in gill-net samples. Within a year class the percentage of females decreased with increase in age. Most Green Bay lake herring mature during their second or third year of life. They are pelagic spawners with most intensive spawning over shallow areas. Spawning takes place between mid-November and mid-December, and eggs hatch in April and May. Lake herring ovaries contained from 3,500 to 11,200 eggs (averaged 6,375). Progress of spawning by age, sex, and length is given. Lake herring were distributed at all depths in Green Bay in early May, were

  16. Skagit River coho salmon life history model—Users’ guide

    Science.gov (United States)

    Woodward, Andrea; Kirby, Grant; Morris, Scott

    2017-09-29

    Natural resource management is conducted in the context of multiple anthropogenic stressors and is further challenged owing to changing climate. Experiments to determine the effects of climate change on complex ecological systems are nearly impossible. However, using a simulation model to synthesize current understanding of key ecological processes through the life cycle of a fish population can provide a platform for exploring potential effects of and management responses to changing conditions. Potential climate-change scenarios can be imposed, responses can be observed, and the effectiveness of potential actions can be evaluated. This approach is limited owing to future conditions likely deviating in range and timing from conditions used to create the model so that the model is expected to become obsolete. In the meantime, however, the modeling process explicitly states assumptions, clarifies information gaps, and provides a means to better understand which relationships are robust and which are vulnerable to changing climate by observing whether and why model output diverges from actual observations through time. The purpose of the model described herein is to provide such a decision-support tool regarding coho (Oncorhynchus kisutch) salmon for the Sauk-Suiattle Indian Tribe of Washington State.The Skagit coho salmon model is implemented in a system dynamics format and has three primary stocks—(1) predicted smolts, (2) realized smolts, and (3) escapement. “Predicted smolts” are the number of smolts expected based on the number of spawners in any year and the Ricker production curve. Pink salmon (Oncorhynchus gorbuscha) return to the Skagit River in odd years, and when they overlap with juvenile rearing coho salmon, coho smolt production is substantially higher than in non-pink years. Therefore, the model uses alternative Ricker equations to predict smolts depending on whether their juvenile year was a pink or non-pink year. The stock “realized smolts

  17. Dissecting molecular stress networks: identifying nodes of divergence between life-history phenotypes.

    Science.gov (United States)

    Schwartz, Tonia S; Bronikowski, Anne M

    2013-02-01

    The complex molecular network that underlies physiological stress response is comprised of nodes (proteins, metabolites, mRNAs, etc.) whose connections span cells, tissues and organs. Variable nodes are points in the network upon which natural selection may act. Thus, identifying variable nodes will reveal how this molecular stress network may evolve among populations in different habitats and how it might impact life-history evolution. Here, we use physiological and genetic assays to test whether laboratory-born juveniles from natural populations of garter snakes (Thamnophis elegans), which have diverged in their life-history phenotypes, vary concomitantly at candidate nodes of the stress response network, (i) under unstressed conditions and (ii) in response to an induced stress. We found that two common measures of stress (plasma corticosterone and liver gene expression of heat shock proteins) increased under stress in both life-history phenotypes. In contrast, the phenotypes diverged at four nodes both under unstressed conditions and in response to stress: circulating levels of reactive oxygen species (superoxide, H(2)O(2)); liver gene expression of GPX1 and erythrocyte DNA damage. Additionally, allele frequencies for SOD2 diverge from neutral markers, suggesting diversifying selection on SOD2 alleles. This study supports the hypothesis that these life-history phenotypes have diverged at the molecular level in how they respond to stress, particularly in nodes regulating oxidative stress. Furthermore, the differences between the life-history phenotypes were more pronounced in females. We discuss the responses to stress in the context of the associated life-history phenotype and the evolutionary pressures thought to be responsible for divergence between the phenotypes. © 2012 Blackwell Publishing Ltd.

  18. Differential reproductive responses to stress reveal the role of life-history strategies within a species.

    Science.gov (United States)

    Schultner, J; Kitaysky, A S; Gabrielsen, G W; Hatch, S A; Bech, C

    2013-11-22

    Life-history strategies describe that 'slow'- in contrast to 'fast'-living species allocate resources cautiously towards reproduction to enhance survival. Recent evidence suggests that variation in strategies exists not only among species but also among populations of the same species. Here, we examined the effect of experimentally induced stress on resource allocation of breeding seabirds in two populations with contrasting life-history strategies: slow-living Pacific and fast-living Atlantic black-legged kittiwakes. We tested the hypothesis that reproductive responses in kittiwakes under stress reflect their life-history strategies. We predicted that in response to stress, Pacific kittiwakes reduce investment in reproduction compared with Atlantic kittiwakes. We exposed chick-rearing kittiwakes to a short-term (3-day) period of increased exogenous corticosterone (CORT), a hormone that is released during food shortages. We examined changes in baseline CORT levels, parental care and effects on offspring. We found that kittiwakes from the two populations invested differently in offspring when facing stress. In response to elevated CORT, Pacific kittiwakes reduced nest attendance and deserted offspring more readily than Atlantic kittiwakes. We observed lower chick growth, a higher stress response in offspring and lower reproductive success in response to CORT implantation in Pacific kittiwakes, whereas the opposite occurred in the Atlantic. Our findings support the hypothesis that life-history strategies predict short-term responses of individuals to stress within a species. We conclude that behaviour and physiology under stress are consistent with trade-off priorities as predicted by life-history theory. We encourage future studies to consider the pivotal role of life-history strategies when interpreting inter-population differences of animal responses to stressful environmental events.

  19. Old world versus new world: life-history alterations in a successful invader introduced across Europe.

    Science.gov (United States)

    Fox, Michael G; Copp, Gordon H

    2014-02-01

    We examined differences in pumpkinseed (Lepomis gibbosus) life-history traits between native North American and introduced European populations, and tested three life-history predictions related to the effect of temperature, growth, waterbody size, and the presence/absence of predators on native and non-native populations. Pumpkinseed populations exhibit more 'opportunistic' traits (earlier maturity, smaller size at maturity, and higher reproductive allocation) in their introduced European range than those in their native range. Predictions of life-history traits were improved when indicators of juvenile growth rate (mean length at age 2), waterbody size (surface area), and thermal regime (air temperature degree-days above 10 °C) were incorporated into models along with continental location, but European pumpkinseed populations exhibit more opportunistic life-history traits than North American populations even when these factors are accounted for. Native pumpkinseed in waterbodies containing piscivores mature later and at a larger size, and have lower gonadosomatic indices than those in waterbodies lacking piscivores, whereas there is no significant difference in the same three life-history traits between European waterbodies containing or lacking piscivores. Because congeneric competitors of the pumpkinseed are absent from Europe, the apparent absence of a predator life-history effect there could also be due to the absence of the major sunfish competitors. In either case, the evolution and maintenance of more opportunistic traits in European pumpkinseed can likely be attributed to enemy release, and this may explain the successful establishment and spread of pumpkinseed in many parts of Europe.

  20. The association between parental life history and offspring phenotype in Atlantic salmon.

    Science.gov (United States)

    Van Leeuwen, Travis E; McLennan, Darryl; McKelvey, Simon; Stewart, David C; Adams, Colin E; Metcalfe, Neil B

    2016-02-01

    In many taxa there is considerable intraspecific variation in life history strategies from within a single population, reflecting alternative routes through which organisms can achieve successful reproduction. Atlantic salmon Salmo salar (Linnaeus) show some of the greatest within-population variability in life history strategies amongst vertebrates, with multiple discrete male and female life histories co-existing and interbreeding on many spawning grounds, although the effect of the various combinations of life histories on offspring traits remains unknown. Using crosses of wild fish we show here that the life history strategy of both parents was significantly associated with a range of offspring traits. Mothers that had spent longer at sea (2 versus 1 year) produced offspring that were heavier, longer and in better condition at the time of first feeding. However, these relationships disappeared shortly after fry had begun feeding exogenously. At this stage, the juvenile rearing environment (i.e. time spent in fresh water as juveniles) of the mother was a better predictor of offspring traits, with mothers that were faster to develop in fresh water (migrating to sea after two rather than three years of age) producing offspring that had higher maximal metabolic rates, aerobic scopes, and that grew faster. Faster developing fathers (1 year old sneaker males) tended to produce offspring that had higher maximal metabolic rates, were in better body condition and grew faster. The results suggest that both genetic effects and those related to parental early and late life history contribute to offspring traits. © 2016. Published by The Company of Biologists Ltd.

  1. Primate enamel evinces long period biological timing and regulation of life history.

    Science.gov (United States)

    Bromage, Timothy G; Hogg, Russell T; Lacruz, Rodrigo S; Hou, Chen

    2012-07-21

    The factor(s) regulating the combination of traits that define the overall life history matrix of mammalian species, comprising attributes such as brain and body weight, age at sexual maturity, lifespan and others, remains a complete mystery. The principal objectives of the present research are (1) to provide evidence for a key variable effecting life history integration and (2) to provide a model for how one would go about investigating the metabolic mechanisms responsible for this rhythm. We suggest here that a biological rhythm with a period greater than the circadian rhythm is responsible for observed variation in primate life history. Evidence for this rhythm derives from studies of tooth enamel formation. Enamel contains an enigmatic periodicity in its microstructure called the striae of Retzius, which develops at species specific intervals in units of whole days. We refer to this enamel rhythm as the repeat interval (RI). For primates, we identify statistically significant relationships between RI and all common life history traits. Importantly, RI also correlates with basal and specific metabolic rates. With the exception of estrous cyclicity, all relationships share a dependence upon body mass. This dependence on body mass informs us that some aspect of metabolism is responsible for periodic energy allocations at RI timescales, regulating cell proliferation rates and growth, thus controlling the pace, patterning, and co-variation of life history traits. Estrous cyclicity relates to the long period rhythm in a body mass-independent manner. The mass-dependency and -independency of life history relationships with RI periodicity align with hypothalamic-mediated neurosecretory anterior and posterior pituitary outputs. We term this period the Havers-Halberg Oscillation (HHO), in reference to Clopton Havers, a 17th Century hard tissue anatomist, and Franz Halberg, a long-time explorer of long-period rhythms. We propose a mathematical model that may help elucidate

  2. The Natural History of Oral Human Papillomavirus in Young Costa Rican Women.

    Science.gov (United States)

    Beachler, Daniel C; Lang Kuhs, Krystle A; Struijk, Linda; Schussler, John; Herrero, Rolando; Porras, Carolina; Hildesheim, Allan; Cortes, Bernal; Sampson, Joshua; Quint, Wim; Gonzalez, Paula; Kreimer, Aimée R

    2017-07-01

    Oral human papillomavirus (HPV) infection and related oropharyngeal cancer are uncommon in lower-income countries, particularly compared to HPV-associated cervical cancer. However, little is known about the natural history of oral HPV in less-developed settings and how it compares to the natural history of cervical HPV. Three hundred fifty women aged 22 to 33 years from the Costa Rica Vaccine Trial provided exfoliated cells from the cervical and oral regions at 2 visits 2 years apart. Samples from both visits were tested for 25 characterized α HPV types by the SPF10 PCR-DNA enzyme immunoassay-LiPA25 version 1 system. Risk factors for oral HPV persistence were calculated utilizing generalized estimating equations with a logistic link. Among the 82 women with characterized α oral HPV DNA detected at baseline, 14 persisted and were detected 2 years later (17.6%; 95% confidence interval [CI], 10.9-28.5%) and was similar to the persistence of α cervical HPV (40/223; 17.7%; 95% CI, 13.1-23.9%; P = 0.86). Acquisition of new α oral HPV type was low; incident infection (1.7%; 95% CI, 0.6-3.7%). Oral HPV DNA is uncommon in young women in Latin America, and often appears to clear within a few years at similar rates to cervical HPV.

  3. Does mental health history explain gender disparities in insomnia symptoms among young adults?

    Science.gov (United States)

    Hale, Lauren; Do, D Phuong; Basurto-Davila, Ricardo; Heron, Melonie; Finch, Brian K; Dubowitz, Tamara; Lurie, Nicole; Bird, Chloe E

    2009-12-01

    Insomnia is the most commonly reported sleep disorder, characterized by trouble falling asleep, staying asleep, or waking up too early. Previous epidemiological data reveal that women are more likely than men to suffer from insomnia symptoms. We investigate the role that mental health history plays in explaining the gender disparity in insomnia symptoms. Using logistic regression, we analyze National Health and Nutritional Examination Survey (NHANES) III interview and laboratory data, merged with data on sociodemographic characteristics of the residential census tract of respondents. Our sample includes 5469 young adults (ages 20-39) from 1429 census tracts. Consistent with previous research, we find that women are more likely to report insomnia symptoms compared to men (16.7% vs. 9.2%). However, in contrast to previous work, we show that the difference between women's and men's odds of insomnia becomes statistically insignificant after adjusting for history of mental health conditions (OR=1.08, p>.05). The gender disparity in insomnia symptoms may be driven by higher prevalence of affective disorders among women. This finding has implications for clinical treatment of both insomnia and depression, especially among women.

  4. Does family history of metabolic syndrome affect the metabolic profile phenotype in young healthy individuals?

    Science.gov (United States)

    Lipińska, Anna; Koczaj-Bremer, Magdalena; Jankowski, Krzysztof; Kaźmierczak, Agnieszka; Ciurzyński, Michał; Ou-Pokrzewińska, Aisha; Mikocka, Ewelina; Lewandowski, Zbigniew; Demkow, Urszula; Pruszczyk, Piotr

    2014-01-01

    Early identification of high-risk individuals is key for the prevention of cardiovascular disease (CVD). The aim of this study was to assess the potential impact of a family history of metabolic syndrome (fhMetS) on the risk of metabolic disorders (abnormal body mass, lipid profile, glucose metabolism, insulin resistance, and blood pressure) in healthy young individuals. We studied CVD risk factors in 90 healthy volunteers, aged 27-39 years; of these, 78 had fhMetS and 12 were without fhMetS (control group). Fasting serum lipids, glucose, and insulin levels were assayed, and anthropometric parameters and blood pressure using, an ambulatory blood pressure monitoring system, were measured. Nutritional and physical activity habits were assessed. Despite similar nutritional and physical activity habits, abnormal body mass was found in 53.2% of the fhMetS participants and 46.1% of the control participants (p = 0.54). The occurrence of obesity was 19.4% and 0%, respectively (p = 0.69). Compared to the control participants, fhMetS was associated with significantly higher total cholesterol (5.46 mmol/L vs. 4.69 mmol/L, p family history of MetS.

  5. The World Turned Upside Down: Exploring Alternate History with Young Adults

    Directory of Open Access Journals (Sweden)

    Justyna Deszcz-Tryhubczak

    2013-05-01

    Full Text Available The purpose of this article is to discuss the theoretical, educational and creative aspects of an alternate history creative writing project with young adults, based on Terry Pratchett’s fantasy novel Nation (2008. First, we focus on the potential of the project as a platform for studying how close teenage audiences are to ideal readers of utopian texts who, as Kenneth Roemer (2003 characterizes them, ‘approach literary utopias as opportunities to discover questions, ambiguities, and contradictions out of which they imagine their own models of utopia’ (p. 2. We also see the proposed project as a useful tool both to promote the knowledge of world history and to provoke a reflection on contributions of individuals to larger historical processes. Moreover, we discuss the project as a means to develop those English language skills necessary for students to construct narratives, express causality, and formulate hypothesis or predictions. Finally, we confront the assumptions underpinning the project with students’ reactions to the novel, as recorded during an initial workshop, and with their creative work in English following the workshop.

  6. Snake River Fall Chinook Salmon Life History Investigations, Annual Report 2008.

    Energy Technology Data Exchange (ETDEWEB)

    Tiffan, Kenneth F. [U.S. Geological Survey; Connor, William P. [U.S. Fish and Wildlife Service; Bellgraph, Brian J. [Pacific Northwest National Laboratory

    2009-09-15

    This study was initiated to provide empirical data and analyses on the dam passage timing, travel rate, survival, and life history variation of fall Chinook salmon that are produced in the Clearwater River. The area of interest for this study focuses on the lower four miles of the Clearwater River and its confluence with the Snake River because this is an area where many fish delay their seaward migration. The goal of the project is to increase our understanding of the environmental and biological factors that affect juvenile life history of fall Chinook salmon in the Clearwater River. The following summaries are provided for each of the individual chapters in this report.

  7. Mutation accumulation may be a minor force in shaping life history traits

    DEFF Research Database (Denmark)

    Dańko, Maciej Jan; Kozłowski, Jan; Vaupel, James Walton

    2012-01-01

    -strings to capture different age-specific mutational patterns. Each pattern represents a genotype and for each genotype we find the life history strategy that maximizes fitness. Genotypes compete with each other and are subject to selection and to new mutations over generations until equilibrium in gene......-frequencies is reached. The mutation-selection equilibrium provides information about mutational load and the differential effects of mutations on a life history trait--the optimal age at maturity. We find that mutations accumulate only at ages with negligible impact on fitness and that mutation accumulation has very...

  8. Life history and demographic drivers of reservoir competence for three tick-borne zoonotic pathogens.

    Directory of Open Access Journals (Sweden)

    Richard S Ostfeld

    Full Text Available Animal and plant species differ dramatically in their quality as hosts for multi-host pathogens, but the causes of this variation are poorly understood. A group of small mammals, including small rodents and shrews, are among the most competent natural reservoirs for three tick-borne zoonotic pathogens, Borrelia burgdorferi, Babesia microti, and Anaplasma phagocytophilum, in eastern North America. For a group of nine commonly-infected mammals spanning >2 orders of magnitude in body mass, we asked whether life history features or surrogates for (unknown encounter rates with ticks, predicted reservoir competence for each pathogen. Life history features associated with a fast pace of life generally were positively correlated with reservoir competence. However, a model comparison approach revealed that host population density, as a proxy for encounter rates between hosts and pathogens, generally received more support than did life history features. The specific life history features and the importance of host population density differed somewhat between the different pathogens. We interpret these results as supporting two alternative but non-exclusive hypotheses for why ecologically widespread, synanthropic species are often the most competent reservoirs for multi-host pathogens. First, multi-host pathogens might adapt to those hosts they are most likely to experience, which are likely to be the most abundant and/or frequently bitten by tick vectors. Second, species with fast life histories might allocate less to certain immune defenses, which could increase their reservoir competence. Results suggest that of the host species that might potentially be exposed, those with comparatively high population densities, small bodies, and fast pace of life will often be keystone reservoirs that should be targeted for surveillance or management.

  9. Life Skills to Address Sexual and Reproductive Health in Young

    African Journals Online (AJOL)

    Esem

    Planning and Professional Development. All this put together in turn ... Results: A model called the ''Life skills intricate in sexual ... family, school and community environments that affect their capacity to .... complexity of human relations, the need to tune into the environment, the effect of culture, gender imbalances, role of the ...

  10. History of Asthma From Childhood and Arterial Stiffness in Asymptomatic Young Adults: The Bogalusa Heart Study.

    Science.gov (United States)

    Sun, Dianjianyi; Li, Xiang; Heianza, Yoriko; Nisa, Hoirun; Shang, Xiaoyun; Rabito, Felicia; Kelly, Tanika; Harville, Emily; Li, Shengxu; He, Jiang; Bazzano, Lydia; Chen, Wei; Qi, Lu

    2018-05-01

    Asthma is related to various cardiovascular risk. Whether a history of asthma from childhood contributes to arterial stiffness in adulthood, a noninvasive surrogate for cardiovascular events, is unknown. Prospective analyses were performed among 1746 Bogalusa Heart Study participants aged 20 to 51 years with data on self-report asthma collected since childhood. Aorta-femoral pulse wave velocity (af-PWV, m/s) was repeatedly assessed among adults ≥aged 18 years. Generalized linear mixed models and generalized linear models were fitted for the repeated measurements of af-PWV and its changes between the last and the first measurements, respectively. After a median follow-up of 11.1 years, participants with a history of asthma from childhood had a higher af-PWV (6.78 versus 6.13; P =0.048) and a greater increase in af-PWV (8.99 versus 2.95; P =0.043) than those without asthma, adjusted for age, sex, race, smoking status, heart rate, body mass index, systolic blood pressure, lipids, and glycemia. In addition, we found significant interactions of asthma with body mass index and systolic blood pressure on af-PWV and its changes ( P for interaction The associations of asthma with af-PWV and its changes appeared to be stronger among participants who were overweight and obese (body mass index ≥25 kg/m 2 ) or with prehypertension and hypertension (systolic blood pressure ≥120 mm Hg) compared with those with a normal body mass index or systolic blood pressure. Our findings indicate that a history of asthma from childhood is associated with higher af-PWV and greater increases in af-PWV, and such associations are stronger among young adults who are overweight or with elevated blood pressure. © 2018 American Heart Association, Inc.

  11. Family relationships, quality of life and social competence in Colombian adolescents and young adults

    Directory of Open Access Journals (Sweden)

    Sonia Carrillo

    2013-08-01

    Full Text Available The main purpose of this study was to assess the infl uence of family relationships on two central aspects of individual functioning: social competence and quality of life in a sample of 103 Colombian adolescents and young adults. Results revealed different signifi cant associations for men and women between the study variables (relationships with parents and sibling, quality of life and social competence. Results are discussed based on the literature on differential effects of family relationships on adolescents’ and young adults’ psychological and social well-being.

  12. Determination of the appropriate use of pavement surface history in the KDOT life-cycle analysis process.

    Science.gov (United States)

    2008-09-01

    The primary objective of this study was to evaluate KDOTs pavement surfacing history and recommend : whether or not the departments life-cycle cost analysis (LCCA) procedure should include a surfacing history : component, and, if so, how the LC...

  13. Plumage quality mediates a life-history trade-off in a migratory bird.

    Science.gov (United States)

    Podlaszczuk, Patrycja; Kamiński, Maciej; Włodarczyk, Radosław; Kaczmarek, Krzysztof; Janiszewski, Tomasz; Minias, Piotr

    2016-01-01

    Moult is one of the most costly activities in the annual cycle of birds and most avian species separate moult from other energy-demanding activities, such as migration. To this end, young birds tend to undergo the first post-juvenile moult before the onset of migration, but in some species the time window for the pre-migratory feather replacement is too narrow. We hypothesized that in such species an increased investment in the structural quality of juvenile feathers may allow to retain juvenile plumage throughout the entire migratory period and delay moult until arriving at wintering grounds, thus avoiding a moult-migration overlap. The effect of juvenile plumage quality on the occurrence of moult-migration overlap was studied in a migratory shorebird, the common snipe Gallinago gallinago . Ca. 400 of first-year common snipe were captured during their final stage of autumn migration through Central Europe. The quality of juvenile feathers was assessed as the mass-length residuals of retained juvenile rectrices. Condition of migrating birds was assessed with the mass of accumulated fat reserves and whole-blood hemoglobin concentration. Path analysis was used to disentangle complex interrelationships between plumage quality, moult and body condition. Snipe which grew higher-quality feathers in the pre-fledging period were less likely to initiate moult during migration. Individuals moulting during migration had lower fat loads and hemoglobin concentrations compared to non-moulting birds, suggesting a trade-off in resource allocation, where energetic costs of moult reduced both energy reserves available for migration and resources available for maintenance of high oxygen capacity of blood. The results of this study indicate that a major life-history trade-off in a migratory bird may be mediated by the quality of juvenile plumage. This is consistent with a silver spoon effect, where early-life investment in feather quality affects future performance of birds during

  14. Population Variation in the Life History of a Land Fish, Alticus arnoldorum, and the Effects of Predation and Density.

    Directory of Open Access Journals (Sweden)

    Edward R M Platt

    Full Text Available Life history variation can often reflect differences in age-specific mortality within populations, with the general expectation that reproduction should be shifted away from ages experiencing increased mortality. Investigators of life history in vertebrates frequently focus on the impact of predation, but there is increasing evidence that predation may have unexpected impacts on population density that in turn prompt unexpected changes in life history. There are also other reasons why density might impact life history independently of predation or mortality more generally. We investigated the consequences of predation and density on life history variation among populations of the Pacific leaping blenny, Alticus arnoldorum. This fish from the island of Guam spends its adult life out of the water on rocks in the splash zone, where it is vulnerable to predation and can be expected to be sensitive to changes in population density that impact resource availability. We found populations invested more in reproduction as predation decreased, while growth rate varied primarily in response to population density. These differences in life history among populations are likely plastic given the extensive gene flow among populations revealed by a previous study. The influence of predation and density on life history was unlikely to have operated independently of each other, with predation rate tending to be associated with reduced population densities. Taken together, our results suggest predation and density can have complex influences on life history, and that plastic life history traits could allow populations to persist in new or rapidly changing environments.

  15. Cellular Metabolic Rate Is Influenced by Life-History Traits in Tropical and Temperate Birds

    OpenAIRE

    Jimenez, Ana Gabriela; Van Brocklyn, James; Wortman, Matthew; Williams, Joseph B.

    2014-01-01

    In general, tropical birds have a "slow pace of life," lower rates of whole-animal metabolism and higher survival rates, than temperate species. A fundamental challenge facing physiological ecologists is the understanding of how variation in life-history at the whole-organism level might be linked to cellular function. Because tropical birds have lower rates of whole-animal metabolism, we hypothesized that cells from tropical species would also have lower rates of cellular metabolism than cel...

  16. Life history trade-offs imposed by dragline use in two money spiders

    OpenAIRE

    Bonte, Dries; Verduyn, Lieselot; Braeckman, Bart

    2016-01-01

    Trade-offs among life history traits are central to understanding the limits of adaptations to stress. In animals, virtually all decisions taken during life are expected to have downstream consequences. To what degree rare, but energy-demanding, decisions carry over to individual performance is rarely studied in arthropods. We used spiders as a model system to test how single investments in silk use - for dispersal or predator escape - affect individual performance. Silk produced for safe lin...

  17. A survey-based analysis of life-long learning patterns of young entrepreneurs

    Directory of Open Access Journals (Sweden)

    Rînciog Johana

    2017-07-01

    Full Text Available Our approach, in this paper, is focused on life-long learning tools that are available for young Romanian entrepreneurs, in their early career stages. Life-long learning in the case of entrepreneurs is not a topic widely covered in scientific literature up to this moment. Most of the scientific papers related to entrepreneurship focus on the idea of innovation and creativity that characterizes entrepreneurship. On the other side, the scientific literature that considers life-long learning, discusses the case of employees or managers, who are required to improve their knowledge and skills in order to perform at the work place. For the current paper, it was aimed to survey the lifelong learning tools available to young Romanian people and to evaluate their efficiency with the help of interviews with young entrepreneurs on their educational path. Otherwise stated, we intended to provide more insights on the learning methods and practices of entrepreneurs, and to establish whether the current formal education represents a strong basis for entrepreneurs’ life-long learning. The research that we performed revealed that young Romanian entrepreneurs practice indeed a lifelong learning based not as much on formal education, as on learning by practicing and networking. Starting from the observations obtained, it was conceived, based on current European best practices and projective discussions with the same young entrepreneurs, a set of life-long learning initiatives that may be promoted in the entrepreneurial community, and we identify the actual steps to be taken by life-long learning education providers in order to implement these initiatives. This paper’s conclusions serve as both a state of the art analysis, in a field which is vital for entrepreneurs surviving in competitive environments, and as a prospective guide for improving the present market of life-long learning programs.

  18. Corticosterone and pace of life in two life-history ecotypes of the garter snake Thamnophis elegans.

    Science.gov (United States)

    Palacios, Maria G; Sparkman, Amanda M; Bronikowski, Anne M

    2012-02-01

    Glucocorticoids are main candidates for mediating life-history trade-offs by regulating the balance between current reproduction and survival. It has been proposed that slow-living organisms should show higher stress-induced glucocorticoid levels that favor self-maintenance rather than current reproduction when compared to fast-living organisms. We tested this hypothesis in replicate populations of two ecotypes of the garter snake (Thamnophis elegans) that exhibit slow and fast pace of life strategies. We subjected free-ranging snakes to a capture-restraint protocol and compared the stress-induced corticosterone levels between slow- and fast-living snakes. We also used a five-year dataset to assess whether baseline corticosterone levels followed the same pattern as stress-induced levels in relation to pace of life. In accordance with the hypothesis, slow-living snakes showed higher stress-induced corticosterone levels than fast-living snakes. Baseline corticosterone levels showed a similar pattern with ecotype, although differences depended on the year of study. Overall, however, levels of glucocorticoids are higher in slow-living than fast-living snakes, which should favor self-maintenance and survival at the expense of current reproduction. The results of the present study are the first to relate glucocorticoid levels and pace of life in a reptilian system and contribute to our understanding of the physiological mechanisms involved in life-history evolution. Copyright © 2011 Elsevier Inc. All rights reserved.

  19. Life history tradeoffs of pathogens and the treatment principle of antibiogenesis

    Directory of Open Access Journals (Sweden)

    Rui-An Wang

    2017-09-01

    Full Text Available There are no eternal individual lives so life continues by relaying with reproduction. Consequently, lifespan and fecundity are two essential genetic traits of life. The life history tradeoffs theory holds that there is an inverse relationship between lifespan and fecundity. This paper proposes two new concepts, i.e., “lifespan of pathogens” and treatment of infections by “antibiogenesis”. The lifespan of pathogens is the time limitation of those tiny lives just as other large creatures. Notably, the lifespan of bacterium is the time interval from the cell division by which it is produced to next division by then its life ends and transforms to two new lives, or dies. Antibiogenesis means inhibiting generation of new lives. By the principle of life history tradeoffs, the lifespan of pathogens determines the speed of their proliferations and consequently the modality of infection. The treatment principle of antibiogenesis requires the duration of treatment to be determined by the lifespan of infected pathogens. The life history tradeoffs theory and the two concepts are helpful to understanding the pathobiology and shaping the clinical aspects of infectious diseases.

  20. Young children and their conduct of everyday life

    DEFF Research Database (Denmark)

    Stanek, Anja Hvidtfeldt; Røn Larsen, Maja

    2015-01-01

    different institutional settings; professional pedagogical work related to supporting children's conduct of everyday life, and finally, the restricted political and bureaucratic conditions for exactly these forms of pedagogical practice. The article addresses the theoretical challenge of understanding...... of problems in day-care. Through a discussion of this apparent contradiction and the conditions for developing a more situated approach, the article aims to contribute to the current professional and political discussions about day-care practice for the youngest children....

  1. Applying an Occupational Classification to a National Representative Sample of Work Histories of Young Men and Women.

    Science.gov (United States)

    Nafziger, Dean H.; And Others

    Holland's occupational classification was used to analyze the work histories of a national representative sample of young men and women age 14-24. This study extended previous tests of the classification in three ways: (1) It was applied for the first time to a national, representative sample of women, (2) For the sample of men, 3-year…

  2. Long-term effects of first degree family history of breast cancer in young women: Recurrences and bilateral breast cancer

    NARCIS (Netherlands)

    Jobsen, Jan J.; van der Palen, Jacobus Adrianus Maria; Brinkhuis, Mariël; Ong, Francisca; Struikmans, Henk

    2016-01-01

    Background. The aim of this study is to analyze the impact of first degree relative (FDR) of young breast cancer patients. Methods. Data were used from our prospective population-based cohort study which started in 1983. The family history (FH) was registered with regard to FDR: the presence or

  3. The role of life histories and trophic interactions in population recovery.

    Science.gov (United States)

    Audzijonyte, Asta; Kuparinen, Anna

    2016-08-01

    Factors affecting population recovery from depletion are at the focus of wildlife management. Particularly, it has been debated how life-history characteristics might affect population recovery ability and productivity. Many exploited fish stocks have shown temporal changes towards earlier maturation and reduced adult body size, potentially owing to evolutionary responses to fishing. Whereas such life-history changes have been widely documented, their potential role on stock's ability to recover from exploitation often remains ignored by traditional fisheries management. We used a marine ecosystem model parameterized for Southeastern Australian ecosystem to explore how changes towards "faster" life histories might affect population per capita growth rate r. We show that for most species changes towards earlier maturation during fishing have a negative effect (3-40% decrease) on r during the recovery phase. Faster juvenile growth and earlier maturation were beneficial early in life, but smaller adult body sizes reduced the lifetime reproductive output and increased adult natural mortality. However, both at intra- and inter-specific level natural mortality and trophic position of the species were as important in determining r as species longevity and age of maturation, suggesting that r cannot be predicted from life-history traits alone. Our study highlights that factors affecting population recovery ability and productivity should be explored in a multi-species context, where both age-specific fecundity and survival schedules are addressed simultaneously. It also suggests that contemporary life-history changes in harvested species are unlikely to increase their resilience and recovery ability. © 2016 Society for Conservation Biology.

  4. Influence of parental history of hypertension on screen time and physical activity in young offspring.

    Science.gov (United States)

    Gopinath, Bamini; Hardy, Louise L; Baur, Louise A; Teber, Erdahl; Mitchell, Paul

    2012-02-01

    Epidemiological data on the relationship between parental hypertension and lifestyle factors among children are limited. We assessed the associations between positive parental history of hypertension with a range of indicators of sedentariness (television viewing, computer and videogame usage) and physical activity (outdoor and indoor activity) among prepubertal children. Six-year-old (1765 of 2238 eligible) students from a random cluster sample of 34 Sydney schools were examined. Parents completed questionnaires about their medical conditions and the child's activities. If the biological mother and/or father had hypertension, then this was classified as positive parental history of hypertension. Parents of 160 (9.2%) children gave a positive family history of hypertension. After adjusting for age, sex, ethnicity, parental education and employment and exposure to passive smoking, children with, compared with those without, a family history of hypertension were more likely to spend above the median time (hours/day) watching television and playing videogames [odds ratio (OR) 1.41, 95% confidence interval (CI) 1.02-1.96; OR 1.52, CI 1.12-2.06, respectively]. The offspring of hypertensive parents were more likely to spend above the median time in total physical activity (OR 1.67, 95% CI 1.23-2.27). Maternal (but not paternal) hypertension was associated with increased time spent watching television (P = 0.03) and in outdoor activity (P = 0.01). Parental hypertension influences the time that prepubertal offspring spend in both active and sedentary pursuits. These findings highlight potential factors that could be addressed in the development of cardiovascular disease-preventive measures starting early in life among the offspring of hypertensive parents.

  5. Effects of (un)employment on young couples' health and life satisfaction.

    Science.gov (United States)

    Haid, Marja-Lena; Seiffge-Krenke, Inge

    2013-01-01

    This study investigated effects of employed and unemployed job status on health outcomes with questionnaires in 50 young couples. Analysis of variance revealed higher pessimism, higher stress levels, and lower life satisfaction in couples in which one partner was unemployed. These couples also exhibited more health risk behaviours compared to couples in which both partners were working. The dyadic analysis of data, using an actor-partner interdependence model, demonstrated strong actor and partner effects for male partner's job status. Being unemployed was significantly associated not only with male partner's life satisfaction but also with the life satisfaction of his female partner. In addition, male partner's pessimism was identified as a significant variable which mediates between male partner's job status and female partner's life satisfaction. The study highlights the relevance of the accomplishment of tasks in the domains of work and partnership during young adulthood and it emphasises the gender specific importance.

  6. Behavioural mediators of genetic life-history trade-offs: a test of the pace-of-life syndrome hypothesis in field crickets.

    Science.gov (United States)

    Santostefano, Francesca; Wilson, Alastair J; Niemelä, Petri T; Dingemanse, Niels J

    2017-10-11

    The pace-of-life syndrome (POLS) hypothesis predicts associations between life history and 'risky' behaviours. Individuals with 'fast' lifestyles should develop faster, reproduce earlier, exhibit more risk-prone behaviours, and die sooner than those with 'slow' lifestyles. While support for POLS has been equivocal to date, studies have relied on individual-level (phenotypic) patterns in which genetic trade-offs may be masked by environmental effects on phenotypes. We estimated genetic correlations between life history (development, lifespan, size) and risky behaviours (exploration, aggression) in a pedigreed population of Mediterranean field crickets ( Gryllus bimaculatus ). Path analyses showed that behaviours mediated some genetic relationships between life history traits, though not those involved in trade-offs. Thus, while specific predictions of POLS theory were not supported, genetic integration of behaviour and life history was present. This implies a major role for risky behaviours in life history evolution. © 2017 The Author(s).

  7. Competition as a source of constraint on life history evolution in natural populations.

    Science.gov (United States)

    Wilson, A J

    2014-01-01

    Competition among individuals is central to our understanding of ecology and population dynamics. However, it could also have major implications for the evolution of resource-dependent life history traits (for example, growth, fecundity) that are important determinants of fitness in natural populations. This is because when competition occurs, the phenotype of each individual will be causally influenced by the phenotypes, and so the genotypes, of competitors. Theory tells us that indirect genetic effects arising from competitive interactions will give rise to the phenomenon of 'evolutionary environmental deterioration', and act as a source of evolutionary constraint on resource-dependent traits under natural selection. However, just how important this constraint is remains an unanswered question. This article seeks to stimulate empirical research in this area, first highlighting some patterns emerging from life history studies that are consistent with a competition-based model of evolutionary constraint, before describing several quantitative modelling strategies that could be usefully applied. A recurrent theme is that rigorous quantification of a competition's impact on life history evolution will require an understanding of the causal pathways and behavioural processes by which genetic (co)variance structures arise. Knowledge of the G-matrix among life history traits is not, in and of itself, sufficient to identify the constraints caused by competition.

  8. Effects of medium renewal and handling stress on life history traits in Daphnia

    NARCIS (Netherlands)

    Rousseaux, S.; Vanoverbeke, J.; Aerts, J.; Declerck, S.A.J.

    2010-01-01

    The zooplankton genus Daphnia is used as a model organism in ecological, ecotoxicological and evolutionary research. It is often used in experimental laboratory setups to examine life history traits under a variety of factors inducing stress. One type of stress, handling stress because of

  9. Becoming a Japanese Language Learner, User, and Teacher: Revelations From Life History Research

    Science.gov (United States)

    Armour, William S.

    2004-01-01

    This article discusses how Sarah Lamond, a Japanese language teacher in Sydney, Australia has juggled three of her identities: second language (L2) learner, L2 user, and L2 teacher. Data come from four interviews used to create an edited life history. These data are used to draw attention to the relationship between L2 learner and language user.…

  10. Psychometrics and life history strategy: the structure and validity of the High K Strategy Scale.

    Science.gov (United States)

    Copping, Lee T; Campbell, Anne; Muncer, Steven

    2014-03-22

    In this paper, we critically review the conceptualization and implementation of psychological measures of life history strategy associated with Differential K theory. The High K Strategy Scale (HKSS: Giosan, 2006) was distributed to a large British sample (n = 809) with the aim of assessing its factor structure and construct validity in relation to theoretically relevant life history variables: age of puberty, age of first sexual encounter, and number of sexual partners. Exploratory and confirmatory factor analyses indicated that the HKSS in its current form did not show an adequate statistical fit to the data. Modifications to improve fit indicated four correlated factors (personal capital, environmental stability, environmental security, and social capital). Later puberty in women was positively associated with measures of the environment and personal capital. Among men, contrary to Differential K predictions but in line with female mate preferences, earlier sexual debut and more sexual partners were positively associated with more favorable environments and higher personal and social capital. We raise concerns about the use of psychometric indicators of lifestyle and personality as proxies for life history strategy when they have not been validated against objective measures derived from contemporary life history theory and when their status as causes, mediators, or correlates has not been investigated.

  11. Life-history traits of the northwest European flora : The LEDA database

    NARCIS (Netherlands)

    Knevel, IC; Bekker, RM; Bakker, JP; Kleyer, M

    An international group of scientists is building a 'trait base', an open internet database of life-history traits of the Northwest European flora (LEDA) that can be used as a tool in planning, in nature conservation and restoration, and in other applied research. The species-trait matrix will

  12. Life history trade-offs and relaxed selection can decrease bacterial virulence in environmental reservoirs.

    Directory of Open Access Journals (Sweden)

    Lauri Mikonranta

    Full Text Available Pathogen virulence is usually thought to evolve in reciprocal selection with the host. While this might be true for obligate pathogens, the life histories of opportunistic pathogens typically alternate between within-host and outside-host environments during the infection-transmission cycle. As a result, opportunistic pathogens are likely to experience conflicting selection pressures across different environments, and this could affect their virulence through life-history trait correlations. We studied these correlations experimentally by exposing an opportunistic bacterial pathogen Serratia marcescens to its natural protist predator Tetrahymena thermophila for 13 weeks, after which we measured changes in bacterial traits related to both anti-predator defence and virulence. We found that anti-predator adaptation (producing predator-resistant biofilm caused a correlative attenuation in virulence. Even though the direct mechanism was not found, reduction in virulence was most clearly connected to a predator-driven loss of a red bacterial pigment, prodigiosin. Moreover, life-history trait evolution was more divergent among replicate populations in the absence of predation, leading also to lowered virulence in some of the 'predator absent' selection lines. Together these findings suggest that the virulence of non-obligatory, opportunistic bacterial pathogens can decrease in environmental reservoirs through life history trade-offs, or random accumulation of mutations that impair virulence traits under relaxed selection.

  13. Selection for life-history traits to maximize population growth in an invasive marine species

    DEFF Research Database (Denmark)

    Jaspers, Cornelia; Marty, Lise; Kiørboe, Thomas

    2018-01-01

    Species establishing outside their natural range, negatively impacting local ecosystems, are of increasing global concern. They often display life-history features characteristic for r-selected populations with fast growth and high reproduction rates to achieve positive population growth rates (r...

  14. Optimal foraging and diel vertical migration in a life history model

    DEFF Research Database (Denmark)

    Sainmont, Julie; Andersen, Ken Haste; Visser, Andre

    in the model, unsuited for life history modeling. We propose a method based on optimal foraging theory to take into account the emergent feeding rates as a function of the copepod metabolic cost, latitude, time and predation. We predict that copepods will balance their growth rate and mortality, playing a safe...

  15. The Juvenile Transition: A Developmental Switch Point in Human Life History

    Science.gov (United States)

    Del Giudice, Marco; Angeleri, Romina; Manera, Valeria

    2009-01-01

    This paper presents a new perspective on the transition from early to middle childhood (i.e., human juvenility), investigated in an integrative evolutionary framework. Juvenility is a crucial life history stage, when social learning and interaction with peers become central developmental functions; here it is argued that the "juvenile transition"…

  16. Putting all your eggs in one basket: life-history strategies, bet hedging, and diversification.

    Science.gov (United States)

    White, Andrew Edward; Li, Yexin Jessica; Griskevicius, Vladas; Neuberg, Steven L; Kenrick, Douglas T

    2013-05-01

    Diversification of resources is a strategy found everywhere from the level of microorganisms to that of giant Wall Street investment firms. We examine the functional nature of diversification using life-history theory-a framework for understanding how organisms navigate resource-allocation trade-offs. This framework suggests that diversification may be adaptive or maladaptive depending on one's life-history strategy and that these differences should be observed under conditions of threat. In three studies, we found that cues of mortality threat interact with one index of life-history strategy, childhood socioeconomic status (SES), to affect diversification. Among those from low-SES backgrounds, mortality threat increased preferences for diversification. However, among those from high-SES backgrounds, mortality threat had the opposite effect, inclining people to put all their eggs in one basket. The same interaction pattern emerged with a potential biomarker of life-history strategy, oxidative stress. These findings highlight when, and for whom, different diversification strategies can be advantageous.

  17. Social environment affects the life history tactic of a phoretic mite

    DEFF Research Database (Denmark)

    Nehring, Volker; Müller, Josef K

    2009-01-01

    Phoretic animals use their hosts for travelling to habitat patches suitable for reproduction. Some species, such as the mite Poecilochirus carabi, are phoretic as juveniles and cannot leave their habitat once they reach adulthood. Previous work has shown that mites exercise choice over the habitat...... influence of the social environment on a phoretic's habitat choice and life history....

  18. The Power of Life Histories: Moving Readers to Greater Acts of Empathy through Literature and Memoir

    Science.gov (United States)

    Lee, Valarie G.; Madden, Marjorie E.

    2016-01-01

    This paper argues that narratives, specifically literature and memoir, offer a way to build empathy and understanding by moving readers to deeper levels of text interpretation and critique. The paper examines a new literacy framework, Life Histories, that uses talk, collaboration, writing, and performance to understand the complex relationships…

  19. State-dependent life-history strategies : A long-term study on oystercatchers

    NARCIS (Netherlands)

    van de Pol, Martijn

    2006-01-01

    The research described in this thesis is part of a long-term field study on free-living Oystercatchers (Haematopus ostralegus), on the Dutch Wadden Sea island of Schiermonnikoog.The study was started in 1983 by Jan Hulscher, and since then a lineage of PhDstudents has investigated life-history

  20. Quality of Life and Behavioral Functioning in Dutch Children with a History of Kawasaki Disease

    NARCIS (Netherlands)

    Tacke, Carline E.; Haverman, Lotte; Berk, Birgit M.; van Rossum, Marion A.; Kuipers, Irene M.; Grootenhuis, Martha A.; Kuijpers, Taco W.

    2012-01-01

    Objective The authors evaluated health-related quality of life (HRQOL) and behavioral functioning in patients with a history of Kawasaki disease (KD). Study design A cross-sectional study was conducted at a tertiary referral center for KD follow-up in 280 patients (mean age 8.6 years, 60.0% male).

  1. Effects of food quality on life history of the rotifer Brachionus calyciflorus Pallas

    NARCIS (Netherlands)

    Jensen, T.C.; Verschoor, A.M.

    2004-01-01

    1. Herbivorous zooplankton face considerable temporal and spatial variation in food quality, to which they respond by adapting their life histories. Zooplankton may even take up mineral nutrients directly, and use these to counter the effects of algal nutrient limitation (mineral compensation). This

  2. Life history, population viability, and the potential for local adaptation in isolated trout populations

    Science.gov (United States)

    K. J. Carim; Y. Vindenes; L. A. Eby; C. Barfoot; L. A. Vollestad

    2017-01-01

    Habitat loss and fragmentation have caused population decline across taxa through impacts on life history diversity, dispersal patterns, and gene flow. Yet, intentional isolation of native fish populations is a frequently used management strategy to protect against negative interactions with invasive fish species. We evaluated the population viability and genetic...

  3. Life-history strategies in parasitoid wasps: a comparative analysis of 'ovigeny'

    NARCIS (Netherlands)

    Jervis, M.A.; Heimpel, G.E.; Ferns, P.N.; Harvey, J.A.; Kidd, N.A.C.

    2001-01-01

    1. Ecologists concerned with life-history strategies of parasitoid wasps have recently focused on interspecific variation in the fraction of the maximum potential lifetime egg complement that is mature when the female emerges into the environment. Species that have all of this complement mature upon

  4. Intersections of life histories and science identities: the stories of three preservice elementary teachers

    Science.gov (United States)

    Avraamidou, Lucy

    2016-03-01

    Grounded within Connelly and Clandinin's conceptualization of teachers' professional identity in terms of 'stories to live by' and through a life-history lens, this multiple case study aimed to respond to the following questions: (a) How do three preservice elementary teachers view themselves as future science teachers? (b) How have the participants' life histories shaped their science identity trajectories? In order to characterize the participants' formation of science identities over time, various data regarding their life histories in relation to science were collected: science biographies, self-portraits, interviews, reflective journals, lesson plans, and classroom observations. The analysis of the data illustrated how the three participants' identities have been in formation from the early years of their lives and how various events, experiences, and interactions had shaped their identities through time and across contexts. These findings are discussed alongside implications for theory, specifically, identity and life-history intersections, for teacher preparation, and for research related to explorations of beginning elementary teachers' identity trajectories.

  5. Intersections of life histories and science identities : the stories of three preservice elementary teachers

    NARCIS (Netherlands)

    Avraamidou, Lucy

    Grounded within Connelly and Clandinin's conceptualization of teachers' professional identity in terms of stories to live by' and through a life-history lens, this multiple case study aimed to respond to the following questions: (a) How do three preservice elementary teachers view themselves as

  6. Masked expression of life-history traits in a highly variable environment

    Science.gov (United States)

    DeBoer, Jason A.; Fontaine, Joseph J.; Chizinski, Christopher J.; Pope, Kevin L.

    2015-01-01

    Differing life-history strategies may act as a constraint on reproductive expression that ultimately limits the ability of individual species to respond to changes in the magnitude or frequency of environmental variation, and potentially underlies the variation often inherent in phenotypic and evolved responses to anthropogenic change. Alternatively, if there are environmental cues that predict reproductive potential, differential expression of life-history strategies may represent differences in the adaptive capacity to optimize current reproductive value given variation in environmental conditions. We compared several aspects of walleye Sander vitreus spawning ecology at two reservoirs that differ in environmental variability (i.e., annual water-level fluctuation) to identify the capacity of phenotypic expression and the corresponding association with age. Despite significant differences in female body and liver masses between reservoirs that differ in environmental variability, we found no difference in reproductive investment measured by egg size and fecundity. Walleye in a highly variable environment appear to exhibit reproductive traits more typical of a short-lived life-history strategy, which may be resultant from the interaction of environmental and anthropogenic pressures. This finding emphasizes the need to identify the degree to which life-history expression represents physiological constraints versus ecological optimization, particularly as anthropogenic change continues to alter environmental conditions. 

  7. Response of endemic Clarias species' life-history biometrics to land ...

    African Journals Online (AJOL)

    The Mpologoma River wetland is highly negatively impacted by rice growing and yet it provides habitat to endemic Clarias species that are important to the wetland fishery. Variations in life-history biometrics of small Clarias species at various wetland sites in relation to land-use changes within the wetland were studied in ...

  8. Intersections of Life Histories and Science Identities: The Stories of Three Preservice Elementary Teachers

    Science.gov (United States)

    Avraamidou, Lucy

    2016-01-01

    Grounded within Connelly and Clandinin's conceptualization of teachers' professional identity in terms of "stories to live by" and through a life-history lens, this multiple case study aimed to respond to the following questions: (a) How do three preservice elementary teachers view themselves as future science teachers? (b) How have the…

  9. From traits to life-history strategies: Deconstructing fish community composition across European seas

    DEFF Research Database (Denmark)

    Pécuchet, Lauréne; Lindegren, Martin; Hidalgo, Manuel

    2017-01-01

    The life history of a species is determined by trade-offs between growth, survival and reproduction to maximize fitness in a given environment. Following a theoretical model, we investigate whether the composition of marine fish communities can be understood in terms of a set of lifehistory...

  10. Geographic, genetic and life-history variability in a sex-changing fish

    Directory of Open Access Journals (Sweden)

    Chiara Benvenuto

    2015-11-01

    Full Text Available Sequential hermaphroditism, commonly referred to as sex change or sex reversal, is a striking phenomenon in mating-system evolution and the most remarkable example of sexual plasticity. Among vertebrates, it is specific to teleosts. Some fish species reproduce initially as females and then change into males (protogynous hermaphrodites or vice versa (protandrous hermaphrodites. The white sea bream, Diplodus sargus, exhibits a high degree of sexual plasticity: populations have been reported to be gonochoristic, protandrous or digynic (with primary females, derived from intersexual juveniles, and secondary females, derived from males. We analysed populations collected from eight different locations across the species distribution range (between the Mediterranean and the North-Eastern Atlantic. These populations are characterized by different degrees of connectivity, spatial demographics and life histories. Using individual-based analyses, we linked the genetic structure of each specimen with environmental heterogeneity, life-history traits and reproductive modes. Our aim is to gather a better understanding of the variation in reproductive life-history strategies in this sexually plastic species. Diplodus sargus is a valuable candidate organism to investigate sequential hermaphroditism and it also has a commercial value. The application of population genetics tools against the background of life-history theory can bring valuable insights for the management of marine resources. The geographical patterns of sex change (and of age- and size-at-sex change linked with population genetics can be pivotal for both theoretical investigations and conservation and management plans in marine areas.

  11. Facultative anadromy in salmonids: linking habitat, individual life history decisions, and population-level consequences

    Science.gov (United States)

    Steven F. Railsback; Bret C. Harvey; Jason L. White

    2014-01-01

    Modeling and management of facultative anadromous salmonids is complicated by their ability to select anadromous or resident life histories. Conventional theory for this behavior assumes individuals select the strategy offering highest expected reproductive success but does not predict how population-level consequences such as a stream’s smolt production emerge from...

  12. Octopus life history relative to age, in a multi-geared developmental fishery

    NARCIS (Netherlands)

    Leporati, S.C.; Hart, A.M.; Larsen, R.; Franken, Linda E; De Graaf, M.

    2015-01-01

    The ability to obtain broad-scale age information for an exploited octopus population enables the identification of essential life history information, such as age at maturity, recruitment pulses and seasonal effects on growth. This study uses stylet weight (reduced internal shell) as a proxy to age

  13. Effects of UV-B irradiated algae on life history traits of Daphnia pulex

    NARCIS (Netherlands)

    De Lange, H.J.; Van Donk, E.

    1997-01-01

    1. The impact of ultraviolet-B (UVB)-irradiated phytoplankton on the life history parameters of Daphnia was studied. Three species of Chlorophyceae (Chlamydomonas reinhardtii, Scenedesmus acutus and S. subspicatus) and one species of Cryptophyceae (Cryptamonas pyrenoidifera) were cultured with and

  14. Herbivore-mediated ecological costs of reproduction shape the life history of an iteroparous plant.

    Science.gov (United States)

    Miller, Tom E X; Tenhumberg, Brigitte; Louda, Svata M

    2008-02-01

    Plant reproduction yields immediate fitness benefits but can be costly in terms of survival, growth, and future fecundity. Life-history theory posits that reproductive strategies are shaped by trade-offs between current and future fitness that result from these direct costs of reproduction. Plant reproduction may also incur indirect ecological costs if it increases susceptibility to herbivores. Yet ecological costs of reproduction have received little empirical attention and remain poorly integrated into life-history theory. Here, we provide evidence for herbivore-mediated ecological costs of reproduction, and we develop theory to examine how these costs influence plant life-history strategies. Field experiments with an iteroparous cactus (Opuntia imbricata) indicated that greater reproductive effort (proportion of meristems allocated to reproduction) led to greater attack by a cactus-feeding insect (Narnia pallidicornis) and that damage by this herbivore reduced reproductive success. A dynamic programming model predicted strongly divergent optimal reproductive strategies when ecological costs were included, compared with when these costs were ignored. Meristem allocation by cacti in the field matched the optimal strategy expected under ecological costs of reproduction. The results indicate that plant reproductive allocation can strongly influence the intensity of interactions with herbivores and that associated ecological costs can play an important selective role in the evolution of plant life histories.

  15. The rate-size trade-off structures intraspecific variation in Daphnia ambigua life history parameters.

    Science.gov (United States)

    DeLong, John P; Hanley, Torrance C

    2013-01-01

    The identification of trade-offs is necessary for understanding the evolution and maintenance of diversity. Here we employ the supply-demand (SD) body size optimization model to predict a trade-off between asymptotic body size and growth rate. We use the SD model to quantitatively predict the slope of the relationship between asymptotic body size and growth rate under high and low food regimes and then test the predictions against observations for Daphnia ambigua. Close quantitative agreement between observed and predicted slopes at both food levels lends support to the model and confirms that a 'rate-size' trade-off structures life history variation in this population. In contrast to classic life history expectations, growth and reproduction were positively correlated after controlling for the rate-size trade-off. We included 12 Daphnia clones in our study, but clone identity explained only some of the variation in life history traits. We also tested the hypothesis that growth rate would be positively related to intergenic spacer length (i.e. the growth rate hypothesis) across clones, but we found that clones with intermediate intergenic spacer lengths had larger asymptotic sizes and slower growth rates. Our results strongly support a resource-based optimization of body size following the SD model. Furthermore, because some resource allocation decisions necessarily precede others, understanding interdependent life history traits may require a more nested approach.

  16. The rate-size trade-off structures intraspecific variation in Daphnia ambigua life history parameters.

    Directory of Open Access Journals (Sweden)

    John P DeLong

    Full Text Available The identification of trade-offs is necessary for understanding the evolution and maintenance of diversity. Here we employ the supply-demand (SD body size optimization model to predict a trade-off between asymptotic body size and growth rate. We use the SD model to quantitatively predict the slope of the relationship between asymptotic body size and growth rate under high and low food regimes and then test the predictions against observations for Daphnia ambigua. Close quantitative agreement between observed and predicted slopes at both food levels lends support to the model and confirms that a 'rate-size' trade-off structures life history variation in this population. In contrast to classic life history expectations, growth and reproduction were positively correlated after controlling for the rate-size trade-off. We included 12 Daphnia clones in our study, but clone identity explained only some of the variation in life history traits. We also tested the hypothesis that growth rate would be positively related to intergenic spacer length (i.e. the growth rate hypothesis across clones, but we found that clones with intermediate intergenic spacer lengths had larger asymptotic sizes and slower growth rates. Our results strongly support a resource-based optimization of body size following the SD model. Furthermore, because some resource allocation decisions necessarily precede others, understanding interdependent life history traits may require a more nested approach.

  17. Life-history and ecological correlates of population change in Dutch breeding birds.

    NARCIS (Netherlands)

    Turnhout, van C.A.M.; Foppen, R.P.B.; Leuven, R.S.E.W.; Strien, van A.J.; Siepel, H.

    2010-01-01

    Predicting relative extinction risks of animals has become a major challenge in conservation biology. Identifying life-history and ecological traits related to the decline of species helps understand what causes population decreases and sets priorities for conservation action. Here, we use Dutch

  18. Disparate relatives: Life histories vary more in genera occupying intermediate environments

    NARCIS (Netherlands)

    Hermant, M.; Hennion, F.; Bartish, I.V.; Yguel, B.; Prinzing, A.

    2012-01-01

    Species within clades are commonly assumed to share similar life history traits, but within a given region some clades show much greater variability in traits than others. Are variable clades older, allowing more time for trait diversification? Or do they occupy particular environments, providing a

  19. Some Life History Narratives of Religious Education Coordinators in Catholic Schools

    Science.gov (United States)

    Rymarz, Richard; Belmonte, Angelo

    2014-01-01

    This paper seeks to gain a better understanding of religious education coordinators (RECs) in contemporary Catholic schools. This is done by using life history narratives to explore how participants came to be RECs. This study takes place in a wider cultural context that sees strong religious commitment, manifested by taking leadership positions…

  20. Executive Risk Propensity and Accounting Conservatism Through the Lens of Life History Theory

    DEFF Research Database (Denmark)

    Holm, Morten; Schneider, Melanie L.

    First, we intend to investigate the impact of CFO risk propensity on accounting conservatism. Second, we will examine the role of CEOs in this context. By drawing on life history theory, we propose variables reflecting executive risk propensity. Based on this, we hypothesize that CFO risk...

  1. Population dynamics, life-history traits of and habitat use by two ...

    African Journals Online (AJOL)

    Population dynamics and life-history traits of two sympatric nothobranchiid killifishes, Epiplatys bifasciatus and E. spilargyreius, were studied for 24 months in an intermittent stream in the Kainji Lake Basin, Nigeria. Epiplatys bifasciatus was more abundant throughout the study period, but monthly abundance of both species ...

  2. Comparing life history characteristics of Lake Michigan’s naturalized and stocked Chinook Salmon

    Science.gov (United States)

    Kerns, Janice A; Rogers, Mark W.; Bunnell, David B.; Claramunt, Randall M.; Collingsworth, Paris D.

    2016-01-01

    Lake Michigan supports popular fisheries for Chinook Salmon Oncorhynchus tshawytscha that have been sustained by stocking since the late 1960s. Natural recruitment of Chinook Salmon in Lake Michigan has increased in the past few decades and currently contributes more than 50% of Chinook Salmon recruits. We hypothesized that selective forces differ for naturalized populations born in the wild and hatchery populations, resulting in divergent life history characteristics with implications for Chinook Salmon population production and the Lake Michigan fishery. First, we conducted a historical analysis to determine if life history characteristics changed through time as the Chinook Salmon population became increasingly naturalized. Next, we conducted a 2-year field study of naturalized and hatchery stocked Chinook Salmon spawning populations to quantify differences in fecundity, egg size, timing of spawning, and size at maturity. In general, our results did not indicate significant life history divergence between naturalized and hatchery-stocked Chinook Salmon populations in Lake Michigan. Although historical changes in adult sex ratio were correlated with the proportion of naturalized individuals, changes in weight at maturity were better explained by density-dependent factors. The field study revealed no divergence in fecundity, timing of spawning, or size at maturity, and only small differences in egg size (hatchery > naturalized). For the near future, our results suggest that the limited life history differences observed between Chinook Salmon of naturalized and hatchery origin will not lead to large differences in characteristics important to the dynamics of the population or fishery.

  3. Synergistic Effects of Different Food Species on Life-History Traits of Daphnia-Galeata

    NARCIS (Netherlands)

    Boersma, M.; Vijverberg, J.

    1995-01-01

    In this paper we describe the life history consequences of feeding Daphnia galeata with different food types in different concentrations. We fed the animals with four concentrations of two green algae Scenedesmus obliquus and Chlamydomonas globosa, given separately as well as in a 1:1 mixture.

  4. Oral health-related quality of life in Swedish young adults

    Directory of Open Access Journals (Sweden)

    Gunvi Johansson

    2015-06-01

    Full Text Available The living conditions of young adults in Sweden have changed during the last decades due to the economic and employment situation in society. Although oral health is mainly considered to be good in this age group, their use of dental care has decreased and their priorities and opportunities regarding oral health are little known. The purpose of this study was to describe the views of Swedish young adults on their oral health and oral health-related quality of life (OHRQoL. The design of the study was qualitative, using content analysis. Sixteen young adults, aged 21–29 years, were interviewed. The findings from the interviews were summarized under the theme “Young adults reflected on their OHRQoL in a time perspective” consisting of three categories: “Past experiences, Present situation, and Future prospects.” The OHRQoL of young adults is dependent not only on their own experiences of oral health during childhood and their received dental care but also on their present self-perceived oral health, oral health habits, and social life; together with their expectations of future oral health. The findings in this study indicate that the oral health awareness and needs of young adults, as well as their expectations of oral care, merit further follow-up.

  5. Niche partitioning in sympatric Gorilla and Pan from Cameroon: implications for life history strategies and for reconstructing the evolution of hominin life history.

    Science.gov (United States)

    Macho, Gabriele A; Lee-Thorp, Julia A

    2014-01-01

    Factors influencing the hominoid life histories are poorly understood, and little is known about how ecological conditions modulate the pace of their development. Yet our limited understanding of these interactions underpins life history interpretations in extinct hominins. Here we determined the synchronisation of dental mineralization/eruption with brain size in a 20th century museum collection of sympatric Gorilla gorilla and Pan troglodytes from Central Cameroon. Using δ13C and δ15N of individuals' hair, we assessed whether and how differences in diet and habitat use may have impacted on ape development. The results show that, overall, gorilla hair δ13C and δ15N values are more variable than those of chimpanzees, and that gorillas are consistently lower in δ13C and δ15N compared to chimpanzees. Within a restricted, isotopically-constrained area, gorilla brain development appears delayed relative to dental mineralization/eruption [or dental development is accelerated relative to brains]: only about 87.8% of adult brain size is attained by the time first permanent molars come into occlusion, whereas it is 92.3% in chimpanzees. Even when M1s are already in full functional occlusion, gorilla brains lag behind those of chimpanzee (91% versus 96.4%), relative to tooth development. Both bootstrap analyses and stable isotope results confirm that these results are unlikely due to sampling error. Rather, δ15N values imply that gorillas are not fully weaned (physiologically mature) until well after M1 are in full functional occlusion. In chimpanzees the transition from infant to adult feeding appears (a) more gradual and (b) earlier relative to somatic development. Taken together, the findings are consistent with life history theory that predicts delayed development when non-density dependent mortality is low, i.e. in closed habitats, and with the "risk aversion" hypothesis for frugivorous species as a means to avert starvation. Furthermore, the results highlight

  6. Fracture History in Osteoporosis: Risk Factors and its Effect on Quality of Life

    Directory of Open Access Journals (Sweden)

    Pınar Kuru

    2014-12-01

    Full Text Available Background: Fractures are one of the main outcomes in osteoporosis and have an important effect on the general health status. Aims: The purpose of this study was to determine the effect of major fracture history on quality of life. We also investigated the important risk factors and their effect on bone mineral density and fracture history. Study Design: Cross-sectional study. Methods: We recruited 105 patients who were admitted to an osteoporosis outpatient clinic. Medical history, family history, calcium intake, physical activity level and biochemical tests were evaluated. Lumbar spine and femur neck bone mineral density were measured. The Qualeffo- 41 questionnaire was also used for evaluating quality of life. Results: The average age of the 105 patients included in the study was 56.04±13.73 and 89% of them were post-menopausal women. The average body mass index was 26.84±5.99, which means that the women were overweight. Also, 48.5% of the patients were diagnosed with osteoporosis and 51.5% of them were diagnosed as low bone density. A total of 34 patients had a fracture history with minor trauma and some of the patients had more than one fracture (12 ankle and foot, 10 forearm, 9 vertebral, 4 hand, 3 hip, 2 rib, 1 tibial. When the patients with and without fracture history were compared, the mean Qualeffo-41 score in patients with fracture was 43.85±2.57 and in the non-fracture group was 36.27±2.01. Conclusion: Forearm, ankle and foot fractures can be commonly seen in osteoporosis patients with fracture history. We suggest that it is important to recognise osteoporosis prior to first fracture and disease-specific quality of life assessment should be done.

  7. Fracture history in osteoporosis: risk factors and its effect on quality of life.

    Science.gov (United States)

    Kuru, Pınar; Akyüz, Gülseren; Cerşit, Hülya Peynirci; Çelenlioğlu, Alp Eren; Cumhur, Ahmet; Biricik, Şefikcan; Kozan, Seda; Gökşen, Aylin; Özdemir, Mikail; Lüleci, Emel

    2014-12-01

    Fractures are one of the main outcomes in osteoporosis and have an important effect on the general health status. The purpose of this study was to determine the effect of major fracture history on quality of life. We also investigated the important risk factors and their effect on bone mineral density and fracture history. Cross-sectional study. We recruited 105 patients who were admitted to an osteoporosis outpatient clinic. Medical history, family history, calcium intake, physical activity level and biochemical tests were evaluated. Lumbar spine and femur neck bone mineral density were measured. The Qualeffo-41 questionnaire was also used for evaluating quality of life. The average age of the 105 patients included in the study was 56.04±13.73 and 89% of them were post-menopausal women. The average body mass index was 26.84±5.99, which means that the women were overweight. Also, 48.5% of the patients were diagnosed with osteoporosis and 51.5% of them were diagnosed as low bone density. A total of 34 patients had a fracture history with minor trauma and some of the patients had more than one fracture (12 ankle and foot, 10 forearm, 9 vertebral, 4 hand, 3 hip, 2 rib, 1 tibial). When the patients with and without fracture history were compared, the mean Qualeffo-41 score in patients with fracture was 43.85±2.57 and in the non-fracture group was 36.27±2.01. Forearm, ankle and foot fractures can be commonly seen in osteoporosis patients with fracture history. We suggest that it is important to recognise osteoporosis prior to first fracture and disease-specific quality of life assessment should be done.

  8. Life-Course Pathways and the Psychosocial Adjustment of Young Adult Women

    Science.gov (United States)

    Amato, Paul R.; Kane, Jennifer B.

    2011-01-01

    We examined 7 life-course pathways from adolescence through the early adult years and their links with general health and psychosocial adjustment among 2,290 women from the National Longitudinal Study of Adolescent Health. Young women who followed a pathway involving college attendance to full-time employment with no family-formation transitions…

  9. Child-Free and Unmarried: Changes in the Life Planning of Young East German Women

    Science.gov (United States)

    Adler, Marina A.

    2004-01-01

    Using evidence from demographic and survey data, this research examines how one decade of post-socialism has changed the life planning of young East German women. Aggregate data reflect marriage and fertility postponement and increased nonmarital birth rates and cohabitation. The analysis shows East German women's stubbornness (Dolling, 2003) in…

  10. The Life Course of Children Born to Unmarried Mothers: Childhood Living Arrangements and Young Adult Outcomes.

    Science.gov (United States)

    Aquilino, William S.

    1996-01-01

    Explored living arrangements among children born to unmarried mothers and the impact of childhood living arrangements on the young adult's life course. Analyses showed that living arrangement patterns after birth to a single mother influenced the likelihood of high school completion, post secondary education, and other conditions. (RJM)

  11. Are Adolescent Substance Users Less Satisfied with Life as Young Adults and if so, Why?

    Science.gov (United States)

    Bogart, Laura M.; Collins, Rebecca L.; Ellickson, Phyllis L.; Klein, David J.

    2007-01-01

    The present study investigated whether adolescent cigarette, alcohol, marijuana, and hard drug use predicts life satisfaction in young adulthood. Survey data were used from a longitudinal cohort of 2376 adolescents at ages 18 and 29, originally recruited from California and Oregon middle schools at age 13. Results of multivariate models indicated…

  12. Parental Perceptions of Life Context Variables for Involvement in Their Young Children's Education

    Science.gov (United States)

    Tekin, Ali Kemal

    2016-01-01

    The purpose of this study was to discover Turkish parents' perceptions of life context variables, including personal knowledge and skills and personal time and energy for involvement activities in their young children's education. The scales used in this study were based on parents' self-report, and included: (1) Parental Perceptions of Personal…

  13. The Mass-Longevity Triangle: Pareto Optimality and the Geometry of Life-History Trait Space

    Science.gov (United States)

    Szekely, Pablo; Korem, Yael; Moran, Uri; Mayo, Avi; Alon, Uri

    2015-01-01

    When organisms need to perform multiple tasks they face a fundamental tradeoff: no phenotype can be optimal at all tasks. This situation was recently analyzed using Pareto optimality, showing that tradeoffs between tasks lead to phenotypes distributed on low dimensional polygons in trait space. The vertices of these polygons are archetypes—phenotypes optimal at a single task. This theory was applied to examples from animal morphology and gene expression. Here we ask whether Pareto optimality theory can apply to life history traits, which include longevity, fecundity and mass. To comprehensively explore the geometry of life history trait space, we analyze a dataset of life history traits of 2105 endothermic species. We find that, to a first approximation, life history traits fall on a triangle in log-mass log-longevity space. The vertices of the triangle suggest three archetypal strategies, exemplified by bats, shrews and whales, with specialists near the vertices and generalists in the middle of the triangle. To a second approximation, the data lies in a tetrahedron, whose extra vertex above the mass-longevity triangle suggests a fourth strategy related to carnivory. Each animal species can thus be placed in a coordinate system according to its distance from the archetypes, which may be useful for genome-scale comparative studies of mammalian aging and other biological aspects. We further demonstrate that Pareto optimality can explain a range of previous studies which found animal and plant phenotypes which lie in triangles in trait space. This study demonstrates the applicability of multi-objective optimization principles to understand life history traits and to infer archetypal strategies that suggest why some mammalian species live much longer than others of similar mass. PMID:26465336

  14. Diagnosing the dangerous demography of manta rays using life history theory

    Directory of Open Access Journals (Sweden)

    Nicholas K. Dulvy

    2014-05-01

    Full Text Available Background. The directed harvest and global trade in the gill plates of mantas, and devil rays, has led to increased fishing pressure and steep population declines in some locations. The slow life history, particularly of the manta rays, is cited as a key reason why such species have little capacity to withstand directed fisheries. Here, we place their life history and demography within the context of other sharks and rays.Methods. Despite the limited availability of data, we use life history theory and comparative analysis to estimate the intrinsic risk of extinction (as indexed by the maximum intrinsic rate of population increase rmax for a typical generic manta ray using a variant of the classic Euler–Lotka demographic model. This model requires only three traits to calculate the maximum intrinsic population growth rate rmax: von Bertalanffy growth rate, annual pup production and age at maturity. To account for the uncertainty in life history parameters, we created plausible parameter ranges and propagate these uncertainties through the model to calculate a distribution of the plausible range of rmax values.Results. The maximum population growth rate rmax of manta ray is most sensitive to the length of the reproductive cycle, and the median rmax of 0.116 year−1 95th percentile [0.089–0.139] is one of the lowest known of the 106 sharks and rays for which we have comparable demographic information.Discussion. In common with other unprotected, unmanaged, high-value large-bodied sharks and rays the combination of very low population growth rates of manta rays, combined with the high value of their gill rakers and the international nature of trade, is highly likely to lead to rapid depletion and potential local extinction unless a rapid conservation management response occurs worldwide. Furthermore, we show that it is possible to derive important insights into the demography extinction risk of data-poor species using well-established life

  15. The Mass-Longevity Triangle: Pareto Optimality and the Geometry of Life-History Trait Space.

    Science.gov (United States)

    Szekely, Pablo; Korem, Yael; Moran, Uri; Mayo, Avi; Alon, Uri

    2015-10-01

    When organisms need to perform multiple tasks they face a fundamental tradeoff: no phenotype can be optimal at all tasks. This situation was recently analyzed using Pareto optimality, showing that tradeoffs between tasks lead to phenotypes distributed on low dimensional polygons in trait space. The vertices of these polygons are archetypes--phenotypes optimal at a single task. This theory was applied to examples from animal morphology and gene expression. Here we ask whether Pareto optimality theory can apply to life history traits, which include longevity, fecundity and mass. To comprehensively explore the geometry of life history trait space, we analyze a dataset of life history traits of 2105 endothermic species. We find that, to a first approximation, life history traits fall on a triangle in log-mass log-longevity space. The vertices of the triangle suggest three archetypal strategies, exemplified by bats, shrews and whales, with specialists near the vertices and generalists in the middle of the triangle. To a second approximation, the data lies in a tetrahedron, whose extra vertex above the mass-longevity triangle suggests a fourth strategy related to carnivory. Each animal species can thus be placed in a coordinate system according to its distance from the archetypes, which may be useful for genome-scale comparative studies of mammalian aging and other biological aspects. We further demonstrate that Pareto optimality can explain a range of previous studies which found animal and plant phenotypes which lie in triangles in trait space. This study demonstrates the applicability of multi-objective optimization principles to understand life history traits and to infer archetypal strategies that suggest why some mammalian species live much longer than others of similar mass.

  16. Evolutionary ecology of endocrine-mediated life-history variation in the garter snake Thamnophis elegans.

    Science.gov (United States)

    Sparkman, Amanda M; Vleck, Carol M; Bronikowski, Anne M

    2009-03-01

    The endocrine system plays an integral role in the regulation of key life-history traits. Insulin-like growth factor-1 (IGF-1) is a hormone that promotes growth and reproduction, and it has been implicated in the reduction of lifespan. IGF-1 is also capable of responding plastically to environmental stimuli such as resource availability and temperature. Thus pleiotropic control of life-history traits by IGF-1 could provide a mechanism for the evolution of correlated life-history traits in a new or changing environment. An ideal system in which to investigate the role of IGF-1 in life-history evolution exists in two ecotypes of the garter snake Thamnophis elegans, which derive from a single recent ancestral source but have evolved genetically divergent life-history characteristics. Snakes from meadow populations near Eagle Lake, California (USA) exhibit slower growth rates, lower annual reproductive output, and longer median adult lifespans relative to populations along the lakeshore. We hypothesized that the IGF-1 system has differentiated between these ecotypes and can account for increased growth and reproduction and reduced survival in lakeshore vs. meadow snakes. We tested for a difference in plasma IGF-1 levels in free-ranging snakes from replicate populations of each ecotype over three years. IGF-1 levels were significantly associated with adult body size, reproductive output, and season in a manner that reflects established differences in prey ecology and age/size-specific reproduction between the ecotypes. These findings are discussed in the context of theoretical expectations for a tradeoff between reproduction and lifespan that is mediated by pleiotropic endocrine mechanisms.

  17. The Mass-Longevity Triangle: Pareto Optimality and the Geometry of Life-History Trait Space.

    Directory of Open Access Journals (Sweden)

    Pablo Szekely

    2015-10-01

    Full Text Available When organisms need to perform multiple tasks they face a fundamental tradeoff: no phenotype can be optimal at all tasks. This situation was recently analyzed using Pareto optimality, showing that tradeoffs between tasks lead to phenotypes distributed on low dimensional polygons in trait space. The vertices of these polygons are archetypes--phenotypes optimal at a single task. This theory was applied to examples from animal morphology and gene expression. Here we ask whether Pareto optimality theory can apply to life history traits, which include longevity, fecundity and mass. To comprehensively explore the geometry of life history trait space, we analyze a dataset of life history traits of 2105 endothermic species. We find that, to a first approximation, life history traits fall on a triangle in log-mass log-longevity space. The vertices of the triangle suggest three archetypal strategies, exemplified by bats, shrews and whales, with specialists near the vertices and generalists in the middle of the triangle. To a second approximation, the data lies in a tetrahedron, whose extra vertex above the mass-longevity triangle suggests a fourth strategy related to carnivory. Each animal species can thus be placed in a coordinate system according to its distance from the archetypes, which may be useful for genome-scale comparative studies of mammalian aging and other biological aspects. We further demonstrate that Pareto optimality can explain a range of previous studies which found animal and plant phenotypes which lie in triangles in trait space. This study demonstrates the applicability of multi-objective optimization principles to understand life history traits and to infer archetypal strategies that suggest why some mammalian species live much longer than others of similar mass.

  18. Diagnosing the dangerous demography of manta rays using life history theory.

    Science.gov (United States)

    Dulvy, Nicholas K; Pardo, Sebastián A; Simpfendorfer, Colin A; Carlson, John K

    2014-01-01

    Background. The directed harvest and global trade in the gill plates of mantas, and devil rays, has led to increased fishing pressure and steep population declines in some locations. The slow life history, particularly of the manta rays, is cited as a key reason why such species have little capacity to withstand directed fisheries. Here, we place their life history and demography within the context of other sharks and rays. Methods. Despite the limited availability of data, we use life history theory and comparative analysis to estimate the intrinsic risk of extinction (as indexed by the maximum intrinsic rate of population increase r max) for a typical generic manta ray using a variant of the classic Euler-Lotka demographic model. This model requires only three traits to calculate the maximum intrinsic population growth rate r max: von Bertalanffy growth rate, annual pup production and age at maturity. To account for the uncertainty in life history parameters, we created plausible parameter ranges and propagate these uncertainties through the model to calculate a distribution of the plausible range of r max values. Results. The maximum population growth rate r max of manta ray is most sensitive to the length of the reproductive cycle, and the median r max of 0.116 year(-1) 95th percentile [0.089-0.139] is one of the lowest known of the 106 sharks and rays for which we have comparable demographic information. Discussion. In common with other unprotected, unmanaged, high-value large-bodied sharks and rays the combination of very low population growth rates of manta rays, combined with the high value of their gill rakers and the international nature of trade, is highly likely to lead to rapid depletion and potential local extinction unless a rapid conservation management response occurs worldwide. Furthermore, we show that it is possible to derive important insights into the demography extinction risk of data-poor species using well-established life history theory.

  19. Positive predictors of quality of life for postpartum mothers with a history of childhood maltreatment.

    Science.gov (United States)

    Irwin, Jessica L; Beeghly, Marjorie; Rosenblum, Katherine L; Muzik, Maria

    2016-12-01

    The postpartum period brings a host of biopsychosocial, familial, and economic changes, which may be challenging for new mothers, especially those with trauma histories. Trauma-exposed women are at heightened risk for psychiatric symptomatology and reduced quality of life. The current study sought to evaluate whether a set of hypothesized promotive factors assessed during the first 18 months postpartum (positive parenting, family cohesion, and maternal resilience) are associated with life satisfaction in this population, after controlling for income and postpartum psychiatric symptoms. Analyses were based on data collected for 266 mother-infant dyads from a longitudinal cohort study, Maternal Anxiety during the Childbearing Years (MACY), of women oversampled for childhood maltreatment history. Hierarchical linear regression was used to evaluate the study hypotheses. Consistent with prior work, greater postpartum psychiatric symptoms and less income predicted poor perceptions of life quality. In hierarchical regressions controlling for income and psychiatric symptoms, positive parenting and family cohesion predicted unique variance in mothers' positive perceptions of life quality, and resilience was predictive beyond all other factors. Factors from multiple levels of analysis (maternal, dyadic, and familial) may serve as promotive factors predicting positive perceptions of life quality among women with childhood trauma histories, even those struggling with high levels of psychiatric or economic distress.

  20. [The life history of Alexander Numan (1780-1852) during his time in Groningen].

    Science.gov (United States)

    Mathijsen, A H

    2001-01-01

    Until the time Numan took on his professorship at the newly established Veterinary School in Utrecht in 1822, he had lived in the Province of Groningen. In order to understand why the minister of Public Education appointed a village doctor from the north of the country as professor for the practice of veteriary medicine, and after some years as director of the school, it was felt essential to investigate his earlier life period. The main sources used are two obituaries, resp. written by his son who was a professor of Law at Groningen University, and by his friend prof. Willem Vrolik who was the secretary of the Academy of Science, supplemented by family histories and some archival research. After a short description of his descent, youth adn education follows the main part devoted to his writings, his medical practice and membership of the Provincial Medical Commission and the Commission for Agriculture. In an appendix some genealogical data are presented on the family of his wife and their children. Alexander lost his father, who was a minister of the Reformed Church, when he was ten years old. He received his education in the circle of family members. A brother of his father, also a minister, teached him Greek and Latin. After this uncle had left the province, he lived in the home of another minister who teached him the modern languages. As this man was involved in politics of the Baravian Republic, young Alexander was exposed to many discussions on the polity of the State. After his mother had remarried with a medical doctor, this man, and also his brother who had a medical practice in another part of the province, complemented the education with an introduction in the sciences. Experiences in their dispensaries, where some knowledge of botany and chemistry could be obtained, and discussions when accompanying them on their visits to patients, were decisive in the choice of his profession. Only at the age of twenty he entered the Medical Faculty of Groningen

  1. Comparative life cycles and life histories of North American Rhabdias spp. (Nematoda: Rhabdiasidae): lungworms from snakes and anurans.

    Science.gov (United States)

    Langford, Gabriel J; Janovy, John

    2009-10-01

    The present study used experimental infections to compare the life cycles and life histories of 6 Rhabdias spp. infecting snakes and anurans. Free-living development of anuran lungworms was primarily limited to heterogonic reproduction, and females utilized matricidal endotoky exclusively, whereas snake lungworms primarily reproduced homogonically and, when heterogonic reproduction occurred, females used a combination of releasing eggs and matricidal endotoky. Infective snake lungworms survived for longer periods in fresh water compared to anuran worms. Infective anuran lungworms penetrated into the skin of frogs and toads; few infections resulted from per os infections. In contrast, snake lungworms were unable to penetrate skin; instead, infective juveniles penetrated into snake esophageal tissue during per os infections. Despite separate points of entry, anuran and snake lungworms both migrated and developed in the fascia, eventually penetrating into the body cavity of the host. Worms molted to adulthood inside the body cavity and subsequently penetrated into the host's lungs, where they fed on blood while becoming gravid. Adult lungworm survival varied among lungworm species, but, in general, snake lungworms were longer lived than anuran worms. Anuran lungworms were poorly suited for transmission via transport hosts, whereas snake lungworms were consistently capable of establishing infections using transport hosts. Overall, these observations suggest that snake and anuran lungworms have discrepant life cycles and life history strategies.

  2. The Societal Impact of Extraterrestrial Life: The Relevance of History and the Social Sciences

    Science.gov (United States)

    Dick, Steven J.

    This chapter reviews past studies on the societal impact of extraterrestrial life and offers four related ways in which history is relevant to the subject: the history of impact thus far, analogical reasoning, impact studies in other areas of science and technology, and studies on the nature of discovery and exploration. We focus particularly on the promise and peril of analogical arguments, since they are by necessity widespread in the field. This chapter also summarizes the relevance of the social sciences, particularly anthropology and sociology, and concludes by taking a closer look at the possible impact of the discovery of extraterrestrial life on theology and philosophy. In undertaking this study we emphasize three bedrock principles: (1) we cannot predict the future; (2) society is not monolithic, implying many impacts depending on religion, culture and worldview; (3) the impact of any discovery of extraterrestrial life is scenario-dependent.

  3. Defoliation and bark harvesting affect life-history traits of a tropical tree

    DEFF Research Database (Denmark)

    Gaoue, Orou; Horvitz, Carol; Ticktin, Tamara

    2013-01-01

    Selectively harvesting whole individuals in managed populations (e.g. fisheries, hunting) has substantial effects on life expectancy and age at maturity. Although demographic rates of trees are impacted by recurrent harvest of plant organs (e.g. fruit, leaf, bark) known as non-timber forest...... of life expectancy to perturbation of vital rates to the elasticities of population growth rate, emphasizing how the two kinds of elasticity address distinct biological issues and management goals. Life expectancy was shorter and reproduction delayed in the dry than in the moist region, indicating a cost...... of drought to life-history traits. Harvesting at constant rates only affects (increased) life expectancy in the moist region and (reduced) age at first reproduction in the dry region. Models in which harvest intensity varies stochastically over time show results similar to those with constant harvesting rate...

  4. Material security, life history, and moralistic religions: A cross-cultural examination

    Science.gov (United States)

    Ross, Cody T.; Apicella, Coren; Atkinson, Quentin D.; Cohen, Emma; McNamara, Rita Anne; Willard, Aiyana K.; Xygalatas, Dimitris; Norenzayan, Ara; Henrich, Joseph

    2018-01-01

    Researchers have recently proposed that “moralistic” religions—those with moral doctrines, moralistic supernatural punishment, and lower emphasis on ritual—emerged as an effect of greater wealth and material security. One interpretation appeals to life history theory, predicting that individuals with “slow life history” strategies will be more attracted to moralistic traditions as a means to judge those with “fast life history” strategies. As we had reservations about the validity of this application of life history theory, we tested these predictions with a data set consisting of 592 individuals from eight diverse societies. Our sample includes individuals from a wide range of traditions, including world religions such as Buddhism, Hinduism and Christianity, but also local traditions rooted in beliefs in animism, ancestor worship, and worship of spirits associated with nature. We first test for the presence of associations between material security, years of formal education, and reproductive success. Consistent with popular life history predictions, we find evidence that material security and education are associated with reduced reproduction. Building on this, we then test whether or not these demographic factors predict the moral concern, punitiveness, attributed knowledge-breadth, and frequency of ritual devotions towards two deities in each society. Here, we find no reliable evidence of a relationship between number of children, material security, or formal education and the individual-level religious beliefs and behaviors. We conclude with a discussion of why life-history theory is an inadequate interpretation for the emergence of factors typifying the moralistic traditions. PMID:29513766

  5. Association of abuse history with symptom severity and quality of life in patients with fibromyalgia.

    Science.gov (United States)

    Jiao, Juan; Vincent, Ann; Cha, Stephen S; Luedtke, Connie A; Oh, Terry H

    2015-03-01

    A high prevalence of abuse has been reported in patients with fibromyalgia. We aimed to examine the association between self-reported abuse history and symptom severity and quality of life (QOL) in 962 patients with fibromyalgia. All patients completed the Fibromyalgia Impact Questionnaire (FIQ) and the Short Form 36 health survey (SF-36). Multivariate regression analyses were performed. In total, 289 patients (30%) reported a history of abuse. Of those who specified abuse types, 161 patients (59%) reported more than 1 type of abuse (36% emotional, 32% physical, 25% sexual, and 7% verbal). Patients in the abuse group were younger and more likely to be female, unemployed, unmarried, and current smokers compared with patients who reported no abuse. After adjusting for these differences, abuse history was associated with worse symptoms, as indicated by a higher FIQ total score (P history was associated with worse QOL, with lower SF-36 scores in all domains except the physical component summary. In conclusion, abuse history in patients with fibromyalgia was associated with worse symptoms and QOL compared with those patients without abuse history. Future studies are needed to assess whether additional tailored interventions as part of fibromyalgia treatment are helpful for patients with a history of abuse.

  6. Growing into disability benefits? Psychosocial course of life of young adults with a chronic somatic disease or disability

    NARCIS (Netherlands)

    Verhoof, Eefje; Maurice-Stam, Heleen; Heymans, Hugo; Grootenhuis, Martha

    2012-01-01

    Aim: A growing number of young adults with somatic diseases/disabilities since childhood apply for disability benefits. The achievement of psychosocial milestones while growing up (course of life) is assumed to be related to job participation. This study assessed the course of life of young adult

  7. Young adults with attention deficit hyperactivity disorder: subtype differences in comorbidity, educational, and clinical history.

    Science.gov (United States)

    Murphy, Kevin R; Barkley, Russell A; Bush, Tracie

    2002-03-01

    The present study sought to examine subtype differences in comorbidity and in antisocial, educational, and treatment histories among young adults (ages 17-27) with attention deficit hyperactivity disorder (ADHD). Comparisons were made between ADHD Combined Type (ADHD-C; N = 60) and Predominantly Inattentive Type (ADHD-I; N = 36) relative to each other and to a community control group of 64 adults. Both ADHD groups had significantly less education, were less likely to have graduated from college, and were more likely to have received special educational placement in high school. Both groups also presented with a greater likelihood of dysthymia, alcohol dependence/abuse, cannabis dependence/abuse, and learning disorders, as well as greater psychological distress on all scales of the SCL-90-R than the control group. Both ADHD groups were more likely to have received psychiatric medication and other mental health services than control adults. In comparison with ADHD-I, adults with ADHD-C differed in only a few respects. The C-type adults were more likely to have oppositional defiant disorder, to experience interpersonal hostility and paranoia, to have attempted suicide, and to have been arrested than the ADHD-I adults. These results are generally consistent with previous studies of ADHD in children, extend these findings to adults with ADHD, and suggest that the greater impulsivity associated with the ADHD-C subtype may predispose toward greater antisocial behavior and its consequences than does ADHD-I type in adults.

  8. From Suns to Life: A Chronological Approach to the History of Life on Earth

    CERN Document Server

    Gargaud, Muriel; López-García, Purificación; Martin, Hervé; Montmerle, Thierry; Pascal, Robert; Reisse, Jacques

    2006-01-01

    This review emerged from several interdisciplinary meetings and schools gathering a group of astronomers, geologists, biologists, and chemists, attempting to share their specialized knowledge around a common question: how did life emerge on Earth? Their ultimate goal was to provide some kind of answer as a prerequisite to an even more demanding question: is life universal? The resulting state-of-the-art articles were written by twenty-five scientists telling a not-so linear story, but on the contrary, highlighting problems, gaps, and controversies. Needless to say, this approach yielded no definitive answers to both questions. However, by adopting a chronological approach to the question of the emergence of life on Earth, the only place where we know for sure that life exists; it was possible to break down this question into several sub-topics that can be addressed by the different disciplines. The main chapters of this review present the formation and evolution of the solar system (3); the building of a habi...

  9. Early Childhood Education Teachers: Life History, Life Course, and the Problem of Family-Work Balance

    Science.gov (United States)

    Bullough, Robert V., Jr.

    2016-01-01

    In contrast to the wider education literature, rather little is known about the lives of early childhood education (ECE) teachers and the impact of those lives on their practice. Drawing on surveys completed by Head Start assistant and lead teachers, teacher lifelines, and interviews, and through the lens of life-course theory, the author portrays…

  10. The Effect of Peer-Education on Sexually Transmitted Diseases and Safer Sexual Life Knowledge and Behaviour of Young People.

    OpenAIRE

    Evin Kirmizitoprak; Zeynep Simsek

    2011-01-01

    Aim: To determine the effect of peer education on the knowledge and attitudes of the young about safe sexual life and sexually transmitted diseases (STDs). Method: In this intervention type epidemiologic study, 1100 youngs were reached at 95% level of significance by probability sampling method. These young people were given education by peer trainers; level of knowledge and attitudes of the young were evaluated before and after education. ‘Young’s Health Information Form’ p...

  11. Life adversities and suicidal behavior in young individuals: a systematic review.

    Science.gov (United States)

    Serafini, Gianluca; Muzio, Caterina; Piccinini, Giulia; Flouri, Eirini; Ferrigno, Gabriella; Pompili, Maurizio; Girardi, Paolo; Amore, Mario

    2015-12-01

    Suicidal behavior in young people is a significant public health problem. However, it is not yet clear whether adversities (adverse life events) may be related to suicidality in adolescence and early adulthood. This paper aimed to investigate systematically the association between the type/number of adverse life events and experiences and suicidal behavior in young people. We developed a detailed strategy to search relevant articles in Pubmed, Scopus, PsycInfo, and Science Direct (January 1980-January 2015) about adverse life events and suicidal behavior. Adverse life events and experiences included maltreatment and violence, loss events, intra-familial problems, school and interpersonal problems. Studies were restricted to suicidal behavior in young people aged 10-25 years. The search yielded 245 articles, of which 28 met our inclusion criteria. Most studies reported a strong association between adversities and suicidality (both suicidal ideation and attempts). Based on the main results, the number of adversities or negative life events experienced seemed to have a positive dose-response relationship with youth suicidal behavior. However, the type of event experienced also appeared to matter: one of the most consistent findings was the association between suicidal behavior and experience of sexual abuse. More prospective studies are needed to elucidate the relative importance of risk accumulation and risk specificity for youth suicide.

  12. Sexual dysfunction risk and quality of life among women with a history of sexual abuse.

    Science.gov (United States)

    Carreiro, Andrea V; Micelli, Ligia P; Sousa, Maria H; Bahamondes, Luis; Fernandes, Arlete

    2016-09-01

    To assess scores for sexual dysfunction risk and quality of life in a cohort of women in Brazil who had a history of sexual abuse. The present study was a secondary analysis of a cross-sectional study conducted between February 1, 2011 and May 31, 2012. Women aged 18-49years attending a family planning clinic at the University of Campinas, Brazil, who were in a heterosexual relationship and reported engaging in sexual intercourse in the 4weeks prior to the study were enrolled. Participants were asked to complete the World Health Organization Quality of Life Questionnaire, Abbreviated Version, and the Female Sexual Function Index (FSFI) questionnaire. Data were grouped based on a history of sexual abuse. An FSFI score of no higher than 26.55 was considered the cut off for sexual dysfunction. The prevalence of FSFI-defined sexual dysfunction was higher in participants with a history of sexual abuse (Phistory of sexual abuse had significantly lower scores across all quality of life domains. Increased risk of sexual dysfunction among women with a history of sexual abuse suggests potential problems in the sex lives of individuals in this population. Healthcare professionals should be alert to this diagnosis. Copyright © 2016 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

  13. Life-Threatening Hypokalemic Paralysis in a Young Bodybuilder

    Directory of Open Access Journals (Sweden)

    Kitty K. T. Cheung

    2014-01-01

    Full Text Available We report a case of life-threatening hypokalemia in a 28-year-old bodybuilder who presented with sudden onset bilateral lower limbs paralysis few days after his bodybuilding competition. His electrocardiogram (ECG showed typical u-waves due to severe hypokalemia (serum potassium 1.6 mmol/L, reference range (RR 3.5–5.0 mmol/L. He was admitted to the intensive care unit (ICU and was treated with potassium replacement. The patient later admitted that he had exposed himself to weight loss agents of unknown nature, purchased online, and large carbohydrate loads in preparation for the competition. He made a full recovery after a few days and discharged himself from the hospital against medical advice. The severe hypokalemia was thought to be caused by several mechanisms to be discussed in this report. With the ever rising number of new fitness centers recently, the ease of online purchasing of almost any drug, and the increasing numbers of youngsters getting into the bodybuilding arena, clinicians should be able to recognize the possible causes of sudden severe hypokalemia in these patients in order to revert the pathophysiology.

  14. Life-threatening hypokalemic paralysis in a young bodybuilder.

    Science.gov (United States)

    Cheung, Kitty K T; So, Wing-Yee; Kong, Alice P S; Ma, Ronald C W; Chow, Francis C C

    2014-01-01

    We report a case of life-threatening hypokalemia in a 28-year-old bodybuilder who presented with sudden onset bilateral lower limbs paralysis few days after his bodybuilding competition. His electrocardiogram (ECG) showed typical u-waves due to severe hypokalemia (serum potassium 1.6 mmol/L, reference range (RR) 3.5-5.0 mmol/L). He was admitted to the intensive care unit (ICU) and was treated with potassium replacement. The patient later admitted that he had exposed himself to weight loss agents of unknown nature, purchased online, and large carbohydrate loads in preparation for the competition. He made a full recovery after a few days and discharged himself from the hospital against medical advice. The severe hypokalemia was thought to be caused by several mechanisms to be discussed in this report. With the ever rising number of new fitness centers recently, the ease of online purchasing of almost any drug, and the increasing numbers of youngsters getting into the bodybuilding arena, clinicians should be able to recognize the possible causes of sudden severe hypokalemia in these patients in order to revert the pathophysiology.

  15. Life-Threatening Hypokalemic Paralysis in a Young Bodybuilder

    Science.gov (United States)

    Cheung, Kitty K. T.; So, Wing-Yee; Kong, Alice P. S.; Ma, Ronald C. W.; Chow, Francis C. C.

    2014-01-01

    We report a case of life-threatening hypokalemia in a 28-year-old bodybuilder who presented with sudden onset bilateral lower limbs paralysis few days after his bodybuilding competition. His electrocardiogram (ECG) showed typical u-waves due to severe hypokalemia (serum potassium 1.6 mmol/L, reference range (RR) 3.5–5.0 mmol/L). He was admitted to the intensive care unit (ICU) and was treated with potassium replacement. The patient later admitted that he had exposed himself to weight loss agents of unknown nature, purchased online, and large carbohydrate loads in preparation for the competition. He made a full recovery after a few days and discharged himself from the hospital against medical advice. The severe hypokalemia was thought to be caused by several mechanisms to be discussed in this report. With the ever rising number of new fitness centers recently, the ease of online purchasing of almost any drug, and the increasing numbers of youngsters getting into the bodybuilding arena, clinicians should be able to recognize the possible causes of sudden severe hypokalemia in these patients in order to revert the pathophysiology. PMID:24660073

  16. The Adolescent and Young Adult with Cancer: A Developmental Life Course Perspective.

    Science.gov (United States)

    Docherty, Sharron L; Kayle, Mariam; Maslow, Gary R; Santacroce, Sheila Judge

    2015-08-01

    Using a Life Course Health Development framework, this article summarizes what is known about the impact of cancer and its treatment on the biopsychosocial world of the adolescent and young adult. Published peer reviewed literature, web-based resources, and cancer-related professional organizations' resources. Adolescents and young adults with cancer, between 15 and 29 years of age, have emerged as a distinct group requiring specialized care. The demands of cancer and its treatment are often directly counter to the developmental needs of this age group and often alter those life course experiences that contribute to resilience, thriving, and flourishing. Providing high-quality care to this age group requires a depth of understanding of the complexity of factors that merge to influence the developmental life course. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Parental Divorce and Family History of Alcohol Disorder: Associations with Young Adults' Alcohol Problems, Marijuana Use, and Interpersonal Relations.

    Science.gov (United States)

    Windle, Michael; Windle, Rebecca C

    2018-06-01

    This study used prospective data from 706 young adults to evaluate the impact of parental divorce and family history of alcoholism (FH+) on the outcomes of offspring alcohol problems, marijuana use, and interpersonal relationships with parents. Assessments of parental divorce were based on parent reports, and young adult outcomes were collected from an offspring cohort (n = 706; X age = 33.25 years; females = 53%) via computer-based individual interviews (CAPI and ACASI). Family history of alcohol disorders for parents was based on assessments by mothers, fathers, and young adults. Parental divorce significantly predicted marijuana use but not alcohol problems. Maternal, but not paternal, alcoholism also significantly predicted marijuana use. Two-way interactions indicated that sex moderated several of the relationships. For example, among those with divorced parents, daughters reported higher levels of conflict with fathers than sons, and sons reported lower levels of maternal support than daughters. Paternal alcoholism was also associated with higher levels of alcohol problems among sons relative to daughters. There was also a significant 2-way interaction between divorce status and maternal alcoholism indicating that young adults who experienced both maternal alcoholism and parental divorce had the highest levels of marijuana use. These findings highlight the role that parental divorce and FH+ have on alcohol problems, marijuana use, and interpersonal relationships in young adulthood, and how sex may moderate some of these more nuanced relationships. Copyright © 2018 by the Research Society on Alcoholism.

  18. Transgenerational plasticity in the sea: context-dependent maternal effects across the life history.

    Science.gov (United States)

    Marshall, Dustin J

    2008-02-01

    Maternal effects can have dramatic influences on the phenotype of offspring. Maternal effects can act as a conduit by which the maternal environment negatively affects offspring fitness, but they can also buffer offspring from environmental change by altering the phenotype of offspring according to local environmental conditions and as such, are a form of transgenerational plasticity. The benefits of maternal effects can be highly context dependent, increasing performance in one life-history stage but reducing it in another. While maternal effects are increasingly well understood in terrestrial systems, studies in the marine environment are typically restricted to a single, early life-history stage. Here, I examine the role of maternal effects across the life history of the bryozoan Bugula neritina. I exposed maternal colonies to a common pollution stress (copper) in the laboratory and then placed them in the field for one week to brood offspring. I then examined the resistance of offspring to copper from toxicant-exposed and toxicant-naïve mothers and found that offspring from toxicant-exposed mothers were larger, more dispersive, and more resistant to copper stress than offspring from naïve mothers. However, maternal exposure history had pervasive, negative effects on the post-metamorphic performance (particularly survival) of offspring: offspring from toxicant-exposed mothers had poorer performance after six weeks in the field, especially when facing high levels of intraspecific competition. Maternal experience can have complex effects on offspring phenotype, enhancing performance in one life-history stage while decreasing performance in another. The context-dependent costs and benefits associated with maternally derived pollution resistance may account for why such resistance is induced rather than continually expressed: mothers must balance the benefits of producing pollution-resistant larvae with the costs of producing poorer performing adults (in the

  19. Patterns of Life Events Preceding the Suicide in Rural Young Chinese: A Case Control Study1

    Science.gov (United States)

    Zhang, Jie; Ma, Zhenyu

    2012-01-01

    Background Previous studies on the Chinese suicide found some life events prior to the suicide different from those in the West, but there is a lack of summary of the Chinese life event patterns to better understand the effects of the social structure on Chinese suicide. Aim We tried to identify the life events that precede the Chinese rural youth suicides and compare them with what found in the West, so as to find the patterns that are particularly true in the Chinese culture contexts. Methods Suicide cases were investigated with a psychological autopsy study in rural China, and local community living controls were also interviewed with the same protocol. Results We collapsed 64 negative life events into six categories: (1) Marriage/Love, (2) Family/Home, (3) Work/Business, (4) Health/Hospital, (5) Law/Legal, (6) Friend/Relationship. About 92.3% of the suicides studied had experienced at least one type of negative life events. The three most common negative life events categories in the past one year were Family/Home (60.7%), Health/Hospital (53.8%) and Marriage/Love (51.3%) in the rural young suicide victims. Conclusions Among the negative life events, those related to family relations, love affairs, and marital issues were most likely to precede a suicide of rural suicides in China, and it is especially true of rural young women. Family is an important social institution in rural China for suicide prevention efforts. PMID:22595373

  20. Prey life-history and bioenergetic responses across a predation gradient.

    Science.gov (United States)

    Rennie, M D; Purchase, C F; Shuter, B J; Collins, N C; Abrams, P A; Morgan, G E

    2010-10-01

    To evaluate the importance of non-consumptive effects of predators on prey life histories under natural conditions, an index of predator abundance was developed for naturally occurring populations of a common prey fish, the yellow perch Perca flavescens, and compared to life-history variables and rates of prey energy acquisition and allocation as estimated from mass balance models. The predation index was positively related to maximum size and size at maturity in both male and female P. flavescens, but not with life span or reproductive investment. The predation index was positively related to size-adjusted specific growth rates and growth efficiencies but negatively related to model estimates of size-adjusted specific consumption and activity rates in both vulnerable (small) and invulnerable (large) size classes of P. flavescens. These observations suggest a trade-off between growth and activity rates, mediated by reduced activity in response to increasing predator densities. Lower growth rates and growth efficiencies in populations with fewer predators, despite increased consumption suggests either 1) a reduction in prey resources at lower predator densities or 2) an intrinsic cost of rapid prey growth that makes it unfavourable unless offset by a perceived threat of predation. This study provides evidence of trade-offs between growth and activity rates induced by predation risk in natural prey fish populations and illustrates how behavioural modification induced through predation can shape the life histories of prey fish species. © 2010 The Authors. Journal compilation © 2010 The Fisheries Society of the British Isles.

  1. The nature and dynamics of world religions: a life-history approach.

    Science.gov (United States)

    Baumard, Nicolas; Chevallier, Coralie

    2015-11-07

    In contrast with tribal and archaic religions, world religions are characterized by a unique emphasis on extended prosociality, restricted sociosexuality, delayed gratification and the belief that these specific behaviours are sanctioned by some kind of supernatural justice. Here, we draw on recent advances in life history theory to explain this pattern of seemingly unrelated features. Life history theory examines how organisms adaptively allocate resources in the face of trade-offs between different life-goals (e.g. growth versus reproduction, exploitation versus exploration). In particular, recent studies have shown that individuals, including humans, adjust their life strategy to the environment through phenotypic plasticity: in a harsh environment, organisms tend to adopt a 'fast' strategy, pursuing smaller but more certain benefits, while in more affluent environments, organisms tend to develop a 'slow' strategy, aiming for larger but less certain benefits. Reviewing a range of recent research, we show that world religions are associated with a form of 'slow' strategy. This framework explains both the promotion of 'slow' behaviours such as altruism, self-regulation and monogamy in modern world religions, and the condemnation of 'fast' behaviours such as selfishness, conspicuous sexuality and materialism. This ecological approach also explains the diffusion pattern of world religions: why they emerged late in human history (500-300 BCE), why they are currently in decline in the most affluent societies and why they persist in some places despite this overall decline. © 2015 The Author(s).

  2. Generation time, life history and the substitution rate of neutral mutations.

    Science.gov (United States)

    Lehtonen, Jussi; Lanfear, Robert

    2014-11-01

    Our understanding of molecular evolution is hampered by a lack of quantitative predictions about how life-history (LH) traits should correlate with substitution rates. Comparative studies have shown that neutral substitution rates vary substantially between species, and evidence shows that much of this diversity is associated with variation in LH traits. However, while these studies often agree, some unexplained and contradictory results have emerged. Explaining these results is difficult without a clear theoretical understanding of the problem. In this study, we derive predictions for the relationships between LH traits and substitution rates in iteroparous species by using demographic theory to relate commonly measured life-history traits to genetic generation time, and by implication to neutral substitution rates. This provides some surprisingly simple explanations for otherwise confusing patterns, such as the association between fecundity and substitution rates. The same framework can be applied to more complex life histories if full life-tables are available. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  3. The nature and dynamics of world religions: a life-history approach

    Science.gov (United States)

    Baumard, Nicolas; Chevallier, Coralie

    2015-01-01

    In contrast with tribal and archaic religions, world religions are characterized by a unique emphasis on extended prosociality, restricted sociosexuality, delayed gratification and the belief that these specific behaviours are sanctioned by some kind of supernatural justice. Here, we draw on recent advances in life history theory to explain this pattern of seemingly unrelated features. Life history theory examines how organisms adaptively allocate resources in the face of trade-offs between different life-goals (e.g. growth versus reproduction, exploitation versus exploration). In particular, recent studies have shown that individuals, including humans, adjust their life strategy to the environment through phenotypic plasticity: in a harsh environment, organisms tend to adopt a ‘fast' strategy, pursuing smaller but more certain benefits, while in more affluent environments, organisms tend to develop a ‘slow' strategy, aiming for larger but less certain benefits. Reviewing a range of recent research, we show that world religions are associated with a form of ‘slow' strategy. This framework explains both the promotion of ‘slow' behaviours such as altruism, self-regulation and monogamy in modern world religions, and the condemnation of ‘fast' behaviours such as selfishness, conspicuous sexuality and materialism. This ecological approach also explains the diffusion pattern of world religions: why they emerged late in human history (500–300 BCE), why they are currently in decline in the most affluent societies and why they persist in some places despite this overall decline. PMID:26511055

  4. Imitative and Direct Learning as Interacting Factors in Life History Evolution.

    Science.gov (United States)

    Bullinaria, John A

    2017-01-01

    The idea that lifetime learning can have a significant effect on life history evolution has recently been explored using a series of artificial life simulations. These involved populations of competing individuals evolving by natural selection to learn to perform well on simplified abstract tasks, with the learning consisting of identifying regularities in their environment. In reality, there is more to learning than that type of direct individual experience, because it often includes a substantial degree of social learning that involves various forms of imitation of what other individuals have learned before them. This article rectifies that omission by incorporating memes and imitative learning into revised versions of the previous approach. To do this reliably requires formulating and testing a general framework for meme-based simulations that will enable more complete investigations of learning as a factor in any life history evolution scenarios. It does that by simulating imitative information transfer in terms of memes being passed between individuals, and developing a process for merging that information with the (possibly inconsistent) information acquired by direct experience, leading to a consistent overall body of learning. The proposed framework is tested on a range of learning variations and a representative set of life history factors to confirm the robustness of the approach. The simulations presented illustrate the types of interactions and tradeoffs that can emerge, and indicate the kinds of species-specific models that could be developed with this approach in the future.

  5. PERSONIFICATION OF WAY OF LIFE TYPES OF YOUNG MEN AND WOMEN – GRADUATES OF THE UNIVERSITY

    Directory of Open Access Journals (Sweden)

    Svetlana Tigranovna Dzhaneryan

    2015-12-01

    Full Text Available The article presents the results of a study aimed at research of the characteristics of personification as the substantive characteristic of each type of the way of life ideals (matrimonial, bohemian, health, career, community, social, social-protection, gnostic of young men and women – graduates of the university.Research methods: survey (questionnaire for study the way of life ideal, a content analysis of the open questions of the questionnaire, expert evaluation categories, methods of nonparametric statistics.Results. The article presents ideas about the way of life ideals, discloses its components and characteristics. In the article designated types of way of life ideals: matrimonial, bohemian, health, career, community, social-protection, gnostic. Established the features of personification of each type of boys and girl’s ideals (who are graduates of the university. The results show that all kinds of way of life ideals are personified; that there are attractive to young people personality traits of real people (or groups whose way of life influences on the construction of their own ideals of life. It is shown that the differentiation of male and female personification of ideals occurs on different parameters: for the ideals of «matrimonial life» and «career life» appears only in the parameter singularity / community; for the ideal of «social life» – in the parameters singularity / community, the psychological portrait, similarities; for the ideal of «health life» – in the parameters singularity / community, the psychological portrait, a means of implementing, similarities.Application of the results: psychological services in high schools and personnel services in different companies.

  6. Defining health-related quality of life for young wheelchair users: A qualitative health economics study.

    Directory of Open Access Journals (Sweden)

    Nathan Bray

    Full Text Available Wheelchairs for children with impaired mobility provide health, developmental and psychosocial benefits, however there is limited understanding of how mobility aids affect the health-related quality of life of children with impaired mobility. Preference-based health-related quality of life outcome measures are used to calculate quality-adjusted life years; an important concept in health economics. The aim of this research was to understand how young wheelchair users and their parents define health-related quality of life in relation to mobility impairment and wheelchair use.The sampling frame was children with impaired mobility (≤18 years who use a wheelchair and their parents. Data were collected through semi-structured face-to-face interviews conducted in participants' homes. Qualitative framework analysis was used to analyse the interview transcripts. An a priori thematic coding framework was developed. Emerging codes were grouped into categories, and refined into analytical themes. The data were used to build an understanding of how children with impaired mobility define health-related quality of life in relation to mobility impairment, and to assess the applicability of two standard measures of health-related quality of life.Eleven children with impaired mobility and 24 parents were interviewed across 27 interviews. Participants defined mobility-related quality of life through three distinct but interrelated concepts: 1 participation and positive experiences; 2 self-worth and feeling fulfilled; 3 health and functioning. A good degree of consensus was found between child and parent responses, although there was some evidence to suggest a shift in perception of mobility-related quality of life with child age.Young wheelchair users define health-related quality of life in a distinct way as a result of their mobility impairment and adaptation use. Generic, preference-based measures of health-related quality of life lack sensitivity in this

  7. LIFE SKILLS OF YOUNG PEOPLE WITH DISABILITIES AND YOUTH WITHOUT DISABILITIES

    Directory of Open Access Journals (Sweden)

    Izeta Husić-Đuzić

    2017-09-01

    Full Text Available The aim of this paper is to determine the differences in life skills of young people with and without disability in chronological age from 18-35 year-old in Tuzla Canton. The respondents sample consists of two sub-samples. First sub-sample contains 50 young people with disability, chronological age from 18-35 of both genders. Second sub-sample contained 50 young people without disability, chronological age from 18- 35 of both genders. Research data were analysed using method of parametric and non-parametric statistics. Frequencies, percentages and measures of central tendency have been calculated (arithmetic mean and standard deviation. P-values have been used for examining the difference between variables and variance analysis has been used for examining the importance of differences. The results show that there is a significant statistical difference between young people with and without disabilities in the of life skills assessed: job retention skills, skills to cope in danger. Based on the results obtained, it is recommended to start the program and training in early age which will make life easier to disabled persons and their families.

  8. Life-history strategies as a tool to identify conservation constraints: A case-study on ants in chalk grasslands

    NARCIS (Netherlands)

    Noordwijk, C.G.E.; Boer, P.; Mabelis, A.A.; Verberk, W.C.E.P.; Siepel, H.

    2012-01-01

    Species’ life-history traits underlie species–environment relationships. Therefore, analysis of species traits, combined into life-history strategies, can be used to identify key factors shaping the local species composition. This is demonstrated in a case-study on ants in chalk grasslands. We

  9. The impact of acne vulgaris on quality of life and psychic health in young adolescents in Greece. Results of a population survey*

    Science.gov (United States)

    Tasoula, Eleni; Gregoriou, Stamatis; Chalikias, John; Lazarou, Dimitris; Danopoulou, Ifigenia; Katsambas, Andreas; Rigopoulos, Dimitris

    2012-01-01

    BACKGROUND Acne vulgaris can severely affect social and psychological functioning. OBJECTIVE The aim of this study was to investigate the impact of acne vulgaris and its severity on Quality of Life of young adolescents in Greece. METHODS We conducted a questionnaire based survey among 1560 adolescent between the ages of 11 and 19 years old and 1531 of these were completed. Adolescents with acne filled all the questions including the Children Dermatology Life Quality Index. Adolescents without acne filled the questions about age, family history of acne, stress and smoking. Data were analyzed with Pearson Chi Square test. RESULTS Acne prevalence was 51.2% affecting both sexes equally. Self reported mild acne was present in 71.2% and moderate-severe acne in 28.8% of the study population. The mean age of the study population was 15.77y. The median score of Children Dermatology Life Quality Index was 4.02. The impact of acne on quality of life is associated with the severity of the acne (pacne experience greater psychosocial and emotional impairment (pacne (pacne are factors that also influence their quality of life. Girls and boys are equally affected. Stress and heredity are correlated with acne and its severity (pacne. CONCLUSION Acne affects Quality of Life of young adolescents in Greece. The impact is proportional to the severity of acne. More severe acne is associated with greater effect on quality of life with implications for self esteem, body image and relationships with others. PMID:23197205

  10. Quality of Life after Young Ischemic Stroke of Mild Severity Is Mainly Influenced by Psychological Factors.

    Science.gov (United States)

    de Bruijn, Marienke A A M; Synhaeve, Nathalie E; van Rijsbergen, Mariëlle W A; de Leeuw, Frank-Erik; Mark, Ruth E; Jansen, Ben P W; de Kort, Paul L M

    2015-10-01

    Long-term prognosis in terms of quality of life (QoL) in young stroke patients is of importance because they usually have a long life expectancy and extensive daily life demands. We aimed at determining which medical and psychological factors influence the QoL in young stroke patients (Young ischemic stroke patients admitted to the St. Elisabeth Hospital and the TweeSteden Hospital, Tilburg, the Netherlands, between 2000 and 2010 were included. One hundred seventy patients and 61 controls filled out the following questionnaires: (1) the Hospital Anxiety and Depression Scale, (2) the Fatigue Assessment Scale, and (3) the shortened World Health Organization Quality of Life scale. Using linear multiple regression analysis, we assessed the factors influencing QoL. QoL did not differ significantly between patients (median modified Rankin Scale score at follow-up, 0) and controls after a mean follow-up of 4.5 (standard deviation, 2.8) years. The presence of excessive fatigue was associated with lower scores on all domains of the QoL (P ≤ .003), but not for general health domain (P = .010). Similarly, depression was associated with worse QoL on the physical (P = .004) and psychological (P = .001) domains and anxiety with lower scores on the psychological (P stroke-specific factors and QoL. Fatigue and to a lesser extent depression and anxiety affect the QoL in young adults after ischemic stroke of mild severity. Therefore, young stroke patients should be informed about, screened, and, if possible, treated for fatigue, depression, and anxiety. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  11. Psychosocial factors impacting on life transitions among young adults with type 2 diabetes

    DEFF Research Database (Denmark)

    Rasmussen, B; Maindal, Helle Terkildsen; Livingston, P

    2016-01-01

    and Danish young adults with T2DM and to identify unmet support needs during life transitions. Method: A qualitative approach was adopted using thematic content analysis of 26 in-depth semi-structured interviews. An inductive descriptive content analysis was undertaken using a comparative coding system......Background: Type 2 diabetes (T2DM) prevalence is increasing rapidly worldwide with a significant increase in young adults. There is limited information about psychosocial and service needs of this group. Aim: To explore similarities and differences in how psychosocial factors impact on Australian...

  12. [Perceived quality of life in mothers of young boys with fragile X syndrome].

    Science.gov (United States)

    Sarimski, Klaus

    2010-01-01

    Quality of life has been conceptualized as a subjective view of one's feeling of well-being. There is evidence for restraints caused by parenting stress as well as resilience in mothers of children with an intellectual handicap. Specifically, we report on an investigation using the family-related life quality questionnaire (FLQ) in mothers of 26 young boys with Fragile X syndrome. Quality of life is affected by parenting stress as well as individual and social coping resources (hope as a personal trait and quality of family relationships). Child-related variables (age, adaptive competence) had no significant effect on perceived quality of life, child temperament and atypical behavior is related indirectly to maternal life satisfaction as a factor determining the degree of parenting stress.

  13. Astrobiology, history, and society life beyond earth and the impact of discovery

    CERN Document Server

    2013-01-01

    This book addresses important current and historical topics in astrobiology and the search for life beyond Earth, including the search for extraterrestrial intelligence (SETI). The first section covers the plurality of worlds debate from antiquity through the nineteenth century, while section two covers the extraterrestrial life debate from the twentieth century to the present. The final section examines the societal impact of discovering life beyond Earth, including both cultural and religious dimensions. Throughout the book, authors draw links between their own chapters and those of other contributors, emphasizing the interconnections between the various strands of the history and societal impact of the search for extraterrestrial life. The chapters are all written by internationally recognized experts and are carefully edited by Douglas Vakoch, professor of clinical psychology at the California Institute of Integral Studies and Director of Interstellar Message Composition at the SETI Institute. This interd...

  14. Niche partitioning in sympatric Gorilla and Pan from Cameroon: implications for life history strategies and for reconstructing the evolution of hominin life history.

    Directory of Open Access Journals (Sweden)

    Gabriele A Macho

    Full Text Available Factors influencing the hominoid life histories are poorly understood, and little is known about how ecological conditions modulate the pace of their development. Yet our limited understanding of these interactions underpins life history interpretations in extinct hominins. Here we determined the synchronisation of dental mineralization/eruption with brain size in a 20th century museum collection of sympatric Gorilla gorilla and Pan troglodytes from Central Cameroon. Using δ13C and δ15N of individuals' hair, we assessed whether and how differences in diet and habitat use may have impacted on ape development. The results show that, overall, gorilla hair δ13C and δ15N values are more variable than those of chimpanzees, and that gorillas are consistently lower in δ13C and δ15N compared to chimpanzees. Within a restricted, isotopically-constrained area, gorilla brain development appears delayed relative to dental mineralization/eruption [or dental development is accelerated relative to brains]: only about 87.8% of adult brain size is attained by the time first permanent molars come into occlusion, whereas it is 92.3% in chimpanzees. Even when M1s are already in full functional occlusion, gorilla brains lag behind those of chimpanzee (91% versus 96.4%, relative to tooth development. Both bootstrap analyses and stable isotope results confirm that these results are unlikely due to sampling error. Rather, δ15N values imply that gorillas are not fully weaned (physiologically mature until well after M1 are in full functional occlusion. In chimpanzees the transition from infant to adult feeding appears (a more gradual and (b earlier relative to somatic development. Taken together, the findings are consistent with life history theory that predicts delayed development when non-density dependent mortality is low, i.e. in closed habitats, and with the "risk aversion" hypothesis for frugivorous species as a means to avert starvation. Furthermore, the

  15. Ecological life histories of the three aquatic nuisance plants, Myriophyllum spicatum, Potamogeton crispus and Elodea canadensis

    Science.gov (United States)

    Nichols, S.A.; Shaw, B.H.

    1986-01-01

    The life histories of Myriophyllum spicatum L., Elodea canadensis Michx., and Potamogeton crispus L., serious aquatic nuisances in many regions of the world, are reviewed to provide insights into the life style of successful aquatic nuisance plants. Specifically, their distribution and spread in North America; their life cycle, productive and reproductive potential; and their ecosystem relationships are reviewed. Hopefully this review will improve a manager's ability to deal with aquatic nuisance problems. It also provides suggestions for basic research needed to develop more effective management practices. It was found that all three species possess a number of adaptations, including an ability to rapidly propagate vegetatively, an opportunistic nature for obtaining nutrients, a life cycle that favors cool weather, and a number of mechanisms which enhance photosynthetic efficiency, which allow them to proliferate. These three species do provide benefits to the ecosystem through their roles in materials cycling and energy flow. Therefore, management of these species should take an integrated approach which recognizes these benefits. The life history information available about the three species varies tremendously; however, a better understanding of resource gain and allocation is needed to manage all three species. Specifically, more research is needed to provide a better understanding of: 1) the role bicarbonate plays in photosynthesis, 2) the role roots play in supplying CO2 to the plabts, 3) resource accumulation and allocation under different temperature and light regimes, 4) resource allocation on a seasonal basis, and 5) nutrient cycling under different management regimes. ?? 1986 Dr W. Junk Publishers.

  16. The Inter-Life Project: Inter-Cultural Spaces for Young People to Use Creative Practices and Research to Assist with Life Changes and Transition

    Science.gov (United States)

    Lally, Vic; Sclater, Madeleine

    2012-01-01

    The aim of the Inter-Life Project was to investigate the use of virtual worlds and creative practices to support the acquisition of transition skills for young people to enhance their management of important life events. In particular, the authors have been investigating the role of the Inter-Life virtual worlds in supporting the development of…

  17. The sense of life satisfaction versus dietary choices of young women doing fitness for recreational purposes

    Science.gov (United States)

    Gacek, Maria

    : The health potential of a person can be improved thanks to recreational physical activity and rational diet. The sense of life satisfaction is also one of significant health resources. The aim of the study was to analyze the relations between the level of life satisfaction and the frequency of consuming selected products in the group of young women who engage in fitness for recreational purposes. The study involved 200 young women (20-30 years old) who regularly do recreational physical activity in fitness clubs in Małopolska. An original questionnaire was used to measure the frequency of consumption of food products, with the following scale: several times a day, once a day, several times a week, once a week, several times a month, and more rarely / never. The Satisfaction With Life Scale (SWLS) by Diener et al., adapted into Polish by Juczyński, was used to measure life satisfaction. The results were analyzed with the use of U Mann-Whitney test and Spearman’s rank correlation coefficients in a statistical package PQStat ver. 1.6. Statistical analysis showed that along with higher life satisfaction, women significantly less often consumed: white bread (plife satisfaction (low vs. high according to the SWLS) showed that women who displayed high life satisfaction significantly more often consumed wholemeal bread (plife satisfaction. The study proved the predictive role of life satisfaction in the development of eating habits of young, physically active women, indicating more rational dietary choices of women with higher levels of this individual quality.

  18. Population transcriptomics of life-history variation in the genus Salmo

    DEFF Research Database (Denmark)

    Giger, T.; Excoffier, L.; Amstutz, U.

    2008-01-01

    with physiological changes that are likely to be involved in preadaptations to seawater in anadromous populations of the genus Salmo, one of which was identified to encode for nucleophosmin 1. Our findings thus provide new molecular insights into salmonid life-history variation, opening new perspectives in the study......In this study, we demonstrate the power of applying complementary DNA (cDNA) microarray technology to identifying candidate loci that exhibit subtle differences in expression levels associated with a complex trait in natural populations of a nonmodel organism. Using a highly replicated experimental...... design involving 180 cDNA microarray experiments, we measured gene-expression levels from 1098 transcript probes in 90 individuals originating from six brown trout (Salmo trutta) and one Atlantic salmon (Salmo salar) population, which follow either a migratory or a sedentary life history. We identified...

  19. Life-history strategies associated with local population variability confer regional stability.

    Science.gov (United States)

    Pribil, Stanislav; Houlahan, Jeff E

    2003-07-07

    A widely held ecological tenet is that, at the local scale, populations of K-selected species (i.e. low fecundity, long lifespan and large body size) will be less variable than populations of r-selected species (i.e. high fecundity, short lifespan and small body size). We examined the relationship between long-term population trends and life-history attributes for 185 bird species in the Czech Republic and found that, at regional spatial scales and over moderate temporal scales (100-120 years), K-selected bird species were more likely to show both large increases and decreases in population size than r-selected species. We conclude that life-history attributes commonly associated with variable populations at the local scale, confer stability at the regional scale.

  20. The changing role of mammal life histories in Late Quaternary extinction vulnerability on continents and islands.

    Science.gov (United States)

    Lyons, S Kathleen; Miller, Joshua H; Fraser, Danielle; Smith, Felisa A; Boyer, Alison; Lindsey, Emily; Mychajliw, Alexis M

    2016-06-01

    Understanding extinction drivers in a human-dominated world is necessary to preserve biodiversity. We provide an overview of Quaternary extinctions and compare mammalian extinction events on continents and islands after human arrival in system-specific prehistoric and historic contexts. We highlight the role of body size and life-history traits in these extinctions. We find a significant size-bias except for extinctions on small islands in historic times. Using phylogenetic regression and classification trees, we find that while life-history traits are poor predictors of historic extinctions, those associated with difficulty in responding quickly to perturbations, such as small litter size, are good predictors of prehistoric extinctions. Our results are consistent with the idea that prehistoric and historic extinctions form a single continuing event with the same likely primary driver, humans, but the diversity of impacts and affected faunas is much greater in historic extinctions. © 2016 The Author(s).

  1. Predicting the natural mortality of marine fish from life history characteristics

    DEFF Research Database (Denmark)

    Gislason, Henrik

    For fish much of the life history is determined by body size. Body size and asymptotic size significantly influences important life history processes such as growth, maturity, egg production, and natural mortality. Futhermore, for a population to persist, offspring must be able to replace...... their parents on a one-for-one basis in the long run. Otherwise the population would either increase exponentially or become extinct. Combining data on growth and specific fecundity in a size-based fish community model of the North Sea and using the requirement of a one-for-one replacement provides...... the information necessary to estimate the scaling of natural mortality with size and asymptotic size. The estimated scaling is compared with output from multispecies fish stock models, with the empirical scaling of the maximum number of recruits per unit of spawning stock biomass with body size...

  2. Shifting the life-history paradigm: discovery of novel habitat use by hawksbill turtles

    Science.gov (United States)

    Gaos, Alexander R.; Lewison, Rebecca L.; Yañez, Ingrid L.; Wallace, Bryan P.; Liles, Michael J.; Nichols, Wallace J.; Baquero, Andres; Hasbún, Carlos R.; Vasquez, Mauricio; Urteaga, José; Seminoff, Jeffrey A.

    2012-01-01

    Adult hawksbill turtles (Eretmochelys imbricata) are typically described as open-coast, coral reef and hard substrate dwellers. Here, we report new satellite tracking data on female hawksbills from several countries in the eastern Pacific that revealed previously undocumented behaviour for adults of the species. In contrast to patterns of habitat use exhibited by their Caribbean and Indo-Pacific counterparts, eastern Pacific hawksbills generally occupied inshore estuaries, wherein they had strong associations with mangrove saltwater forests. The use of inshore habitats and affinities with mangrove saltwater forests presents a previously unknown life-history paradigm for adult hawksbill turtles and suggests a potentially unique evolutionary trajectory for the species. Our findings highlight the variability in life-history strategies that marine turtles and other wide-ranging marine wildlife may exhibit among ocean regions, and the importance of understanding such disparities from an ecological and management perspective. PMID:21880620

  3. Relating life-history traits, environmental constraints and local extinctions in river fish

    OpenAIRE

    Bergerot, B.; Hugueny, Bernard; Belliard, J.

    2015-01-01

    The life histories of freshwater fish are widely studied because they represent fundamental determinants of population performances. However, a gap remains in our understanding of how species traits may predispose species to extinction in a changing environment. In this study, based on a large data set provided by the French National Agency for Water and Aquatic Environment (325 sites), we analysed factors that explain the probability of local extinction in 40 freshwater species across French...

  4. Can sexual selection drive female life histories? A comparative study on Galliform birds.

    Science.gov (United States)

    Kolm, N; Stein, R W; Mooers, A Ø; Verspoor, J J; Cunningham, E J A

    2007-03-01

    Sexual selection has been identified as a major evolutionary force shaping male life history traits but its impact on female life history evolution is less clear. Here we examine the impact of sexual selection on three key female traits (body size, egg size and clutch size) in Galliform birds. Using comparative independent contrast analyses and directional discrete analyses, based on published data and a new genera-level supertree phylogeny of Galliform birds, we investigated how sexual selection [quantified as sexual size dimorphism (SSD) and social mating system (MS)] affects these three important female traits. We found that female body mass was strongly and positively correlated with egg size but not with clutch size, and that clutch size decreased as egg size increased. We established that SSD was related to MS, and then used SSD as a proxy of the strength of sexual selection. We found both a positive relationship between SSD and female body mass and egg size and that increases in female body mass and egg size tend to occur following increases in SSD in this bird order. This pattern of female body mass increases lagging behind changes in SSD, established using our directional discrete analysis, suggests that female body mass increases as a response to increases in the level of sexual selection and not simply through a strong genetic relationship with male body mass. This suggests that sexual selection is linked to changes in female life history traits in Galliformes and we discuss how this link may shape patterns of life history variation among species.

  5. Revealing life-history traits by contrasting genetic estimations with predictions of effective population size.

    Science.gov (United States)

    Greenbaum, Gili; Renan, Sharon; Templeton, Alan R; Bouskila, Amos; Saltz, David; Rubenstein, Daniel I; Bar-David, Shirli

    2017-12-22

    Effective population size, a central concept in conservation biology, is now routinely estimated from genetic surveys and can also be theoretically predicted from demographic, life-history, and mating-system data. By evaluating the consistency of theoretical predictions with empirically estimated effective size, insights can be gained regarding life-history characteristics and the relative impact of different life-history traits on genetic drift. These insights can be used to design and inform management strategies aimed at increasing effective population size. We demonstrated this approach by addressing the conservation of a reintroduced population of Asiatic wild ass (Equus hemionus). We estimated the variance effective size (N ev ) from genetic data (N ev =24.3) and formulated predictions for the impacts on N ev of demography, polygyny, female variance in lifetime reproductive success (RS), and heritability of female RS. By contrasting the genetic estimation with theoretical predictions, we found that polygyny was the strongest factor affecting genetic drift because only when accounting for polygyny were predictions consistent with the genetically measured N ev . The comparison of effective-size estimation and predictions indicated that 10.6% of the males mated per generation when heritability of female RS was unaccounted for (polygyny responsible for 81% decrease in N ev ) and 19.5% mated when female RS was accounted for (polygyny responsible for 67% decrease in N ev ). Heritability of female RS also affected N ev ; hf2=0.91 (heritability responsible for 41% decrease in N ev ). The low effective size is of concern, and we suggest that management actions focus on factors identified as strongly affecting Nev, namely, increasing the availability of artificial water sources to increase number of dominant males contributing to the gene pool. This approach, evaluating life-history hypotheses in light of their impact on effective population size, and contrasting

  6. Potential fitness benefits of the half-pounder life history in Klamath River steelhead

    Science.gov (United States)

    Hodge, Brian W.; Wilzbach, Peggy; Duffy, Walter G.

    2014-01-01

    Steelhead Oncorhynchus mykiss from several of the world's rivers display the half-pounder life history, a variant characterized by an amphidromous (and, less often, anadromous) return to freshwater in the year of initial ocean entry. We evaluated factors related to expression of the half-pounder life history in wild steelhead from the lower Klamath River basin, California. We also evaluated fitness consequences of the half-pounder phenotype using a simple life history model that was parameterized with our empirical data and outputs from a regional survival equation. The incidence of the half-pounder life history differed among subbasins of origin and smolt ages. Precocious maturation occurred in approximately 8% of half-pounders and was best predicted by individual length in freshwater preceding ocean entry. Adult steelhead of the half-pounder phenotype were smaller and less fecund at age than adult steelhead of the alternative (ocean contingent) phenotype. However, our data suggest that fish of the half-pounder phenotype are more likely to spawn repeatedly than are fish of the ocean contingent phenotype. Models predicted that if lifetime survivorship were equal between phenotypes, the fitness of the half-pounder phenotype would be 17–28% lower than that of the ocean contingent phenotype. To meet the condition of equal fitness between phenotypes would require that first-year ocean survival be 21–40% higher among half-pounders in freshwater than among their cohorts at sea. We concluded that continued expression of the half-pounder phenotype is favored by precocious maturation and increased survival relative to that of the ocean contingent phenotype.

  7. Variation in organotin accumulation in relation to the life history in the Japanese eel Anguilla japonica

    Science.gov (United States)

    Ohji, Madoka; Harino, Hiroya; Arai, Takaomi

    2009-08-01

    In order to examine the ecological risks caused by organotin compounds (OTs) in diadromous fish migrating between sea and freshwaters, tributyltin (TBT) and triphenyltin (TPT) compounds and their breakdown products were determined in the catadromous eel Anguilla japonica, which has sea, estuarine and river life histories, collected in Japanese sea, brackish and freshwaters within the same region. Ontogenic changes in otolith strontium (Sr) and calcium (Ca) concentrations were examined along the life history transect to discriminate the migration type. There were generally three different patterns, which were categorized as 'sea eels', 'estuarine eels' and 'river eels' according to the otolith Sr:Ca ratio. The concentrations of TBT in silver eels (mature eels) were significantly higher than that in yellow eels (immature eels), and the percentages of TBT were also higher in silver eels than in yellow eels. A positive correlation was found between TBT concentration and the gonad-somatic index (GSI). It is thus considered that silver eels have a higher risk of contamination by TBT than yellow eels. TBT and TPT concentrations in sea eels were significantly higher than those in river eels, while no significant differences were observed in TBT and TPT concentrations in estuarine eels compared to sea and river eels. These results suggest that sea eels have a higher ecological risk of OT contamination than river eels during their life history, and the risk of OTs in estuarine eels is considered to be intermediate between that of sea and river eels. Positive linear relationships were found between Sr:Ca ratios and the concentrations of TBT and TPT. Therefore, these results suggest that the ecological risk of OTs increase as the sea residence period in the eel becomes longer. TBT and TPT concentrations in sea eels were significantly higher than those in river eels even at the same growth stage. Thus, it is clear that migratory type is the most important factor for OT

  8. Extrinsic and intrinsic factors that shape the life history of the short living scallop Argopecten ventricosus

    OpenAIRE

    Guerra, Citlali

    2011-01-01

    The scallop Argopecten ventricosus is characterized by its high swimming activity, fast growth, high reproductive effort and the early age to get first sexual maturity. These traits may be the result of the adaptation to a specific environment that favors an active lifestyle and a short lifespan (2 years). This opens the question of how environmental factors modulate the way a short living marine ectotherm budget energy investments among life history traits and how this modulation impacts the...

  9. Life history and spatial determinants of somatic growth dynamics in Komodo dragon populations

    OpenAIRE

    Laver, Rj; Purwandana, D; Ariefiandy, A; Imansyah, J; Forsyth, D; Ciofi, C; Jessop, Ts

    2012-01-01

    Somatic growth patterns represent a major component of organismal fitness and may vary among sexes and populations due to genetic and environmental processes leading to profound differences in life-history and demography. This study considered the ontogenic, sex-specific and spatial dynamics of somatic growth patterns in ten populations of the world's largest lizard the Komodo dragon (Varanus komodoensis). The growth of 400 individual Komodo dragons was measured in a capture-mark-recapture st...

  10. Harsh Environments, Life History Strategies, and Adjustment: A Longitudinal Study of Oregon Youth

    OpenAIRE

    Hampson, Sarah E.; Andrews, Judy A.; Barckley, Maureen; Gerrard, Meg; Gibbons, Frederick X.

    2016-01-01

    We modeled the effects of harsh environments in childhood on adjustment in early emerging adulthood, through parenting style and the development of fast Life History Strategies (LHS; risky beliefs and behaviors) in adolescence. Participants were from the Oregon Youth Substance Use Project (N = 988; 85.7% White). Five cohorts of children in Grades 1–5 at recruitment were assessed through one-year post high school. Greater environmental harshness (neighborhood quality and family poverty) in Gra...

  11. Environmentally-induced plasticity of life history parameters in the cladoceran Simocephalus vetulus

    Czech Academy of Sciences Publication Activity Database

    Šorf, Michal; Cábová, M.; Rychtecký, Pavel

    2017-01-01

    Roč. 66, SEP 01 (2017), s. 40-43 ISSN 0075-9511 R&D Projects: GA ČR(CZ) GA14-29857S Institutional support: RVO:60077344 Keywords : cladocera * life history traits * feeding Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 1.427, year: 2016 http://www.sciencedirect.com/science/article/pii/S007595111630192X

  12. How universal are reserve design rules? A test using butterflies and their life history traits

    Czech Academy of Sciences Publication Activity Database

    Bartoňová, Alena; Beneš, Jiří; Faltýnek Fric, Zdeněk; Chobot, K.; Konvička, Martin

    2016-01-01

    Roč. 39, č. 5 (2016), s. 456-464 ISSN 0906-7590 R&D Projects: GA ČR GAP505/10/2167 Grant - others:GA JU(CZ) 04-168/2013/P Institutional support: RVO:60077344 Keywords : life history traits * butterflies * heterogeneity Subject RIV: EH - Ecology, Behaviour Impact factor: 4.902, year: 2016 http://onlinelibrary.wiley.com/doi/10.1111/ecog.01642/abstract

  13. Periodic life history strategy of Psectrogaster rutiloides, Kner 1858, in the Iquitos region, Peruvian Amazon

    OpenAIRE

    Garcia-Vasquez, A.; Vargas, G.; Sanchez, H.; Tello, S.; Duponchelle, Fabrice

    2015-01-01

    The present study objective was to determine some of the main life history characteristics of the chiochio, Psectrogaster rutiloides, a heavily fished, yet poorly studied species of the Peruvian Amazon. Over an annual cycle between 2006 and 2007 a monthly sampling of P. rutiloides on the Iquitos market provided a total of 2973 individuals. The species reproduces during the rainy season, during the first part of the flooding period. First sexual maturity is reached at about 2years of age and 9...

  14. Growth, life history, and species interactions of bluegill sunfish (Lepomis macrochirus) under heavy predation

    Energy Technology Data Exchange (ETDEWEB)

    Belk, Mark Carl [Univ. of Georgia, Athens, GA (United States)

    1992-01-01

    The purpose of this study was, first, to compare growth and life history characteristics of an unfished population of bluegill sunfish (Lepomis macrochirus) in the presence of an abundant predator population to characteristic exhibited by bluegills in typical southeastern US reservoirs where the abundance of predators is reduced, but fishing is increased. The second objective was to determine if differences observed between populations were determined genetically or environmentally.

  15. Life history of the stem tetrapod Acanthostega revealed by synchrotron microtomography.

    Science.gov (United States)

    Sanchez, Sophie; Tafforeau, Paul; Clack, Jennifer A; Ahlberg, Per E

    2016-09-15

    The transition from fish to tetrapod was arguably the most radical series of adaptive shifts in vertebrate evolutionary history. Data are accumulating rapidly for most aspects of these events, but the life histories of the earliest tetrapods remain completely unknown, leaving a major gap in our understanding of these organisms as living animals. Symptomatic of this problem is the unspoken assumption that the largest known Devonian tetrapod fossils represent adult individuals. Here we present the first, to our knowledge, life history data for a Devonian tetrapod, from the Acanthostega mass-death deposit of Stensiö Bjerg, East Greenland. Using propagation phase-contrast synchrotron microtomography (PPC-SRμCT) to visualize the histology of humeri (upper arm bones) and infer their growth histories, we show that even the largest individuals from this deposit are juveniles. A long early juvenile stage with unossified limb bones, during which individuals grew to almost final size, was followed by a slow-growing late juvenile stage with ossified limbs that lasted for at least six years in some individuals. The late onset of limb ossification suggests that the juveniles were exclusively aquatic, and the predominance of juveniles in the sample suggests segregated distributions of juveniles and adults at least at certain times. The absolute size at which limb ossification began differs greatly between individuals, suggesting the possibility of sexual dimorphism, adaptive strategies or competition-related size variation.

  16. Evaluating hair as a predictor of blood mercury: the influence of ontogenetic phase and life history in pinnipeds

    Science.gov (United States)

    Peterson, Sarah H.; McHuron, Elizabeth A.; Kennedy, Stephanie N.; Ackerman, Joshua T.; Rea, Lorrie D.; Castellini, J. Margaret; O'Hara, Todd M.; Costa, Daniel P.

    2016-01-01

    Mercury (Hg) biomonitoring of pinnipeds increasingly utilizes nonlethally collected tissues such as hair and blood. The relationship between total Hg concentrations ([THg]) in these tissues is not well understood for marine mammals, but it can be important for interpretation of tissue concentrations with respect to ecotoxicology and biomonitoring. We examined [THg] in blood and hair in multiple age classes of four pinniped species. For each species, we used paired blood and hair samples to quantify the ability of [THg] in hair to predict [THg] in blood at the time of sampling and examined the influence of varying ontogenetic phases and life history of the sampled animals. Overall, we found that the relationship between [THg] in hair and blood was affected by factors including age class, weaning status, growth, and the time difference between hair growth and sample collection. Hair [THg] was moderately to strongly predictive of current blood [THg] for adult female Steller sea lions (Eumetopias jubatus), adult female California sea lions (Zalophus californianus), and adult harbor seals (Phoca vitulina), whereas hair [THg] was poorly predictive or not predictive (different times of year) of blood [THg] for adult northern elephant seals (Mirounga angustirostris). Within species, except for very young pups, hair [THg] was a weaker predictor of blood [THg] for prereproductive animals than for adults likely due to growth, variability in foraging behavior, and transitions between ontogenetic phases. Our results indicate that the relationship between hair [THg] and blood [THg] in pinnipeds is variable and that ontogenetic phase and life history should be considered when interpreting [THg] in these tissues.

  17. Language and life history: a new perspective on the development and evolution of human language.

    Science.gov (United States)

    Locke, John L; Bogin, Barry

    2006-06-01

    It has long been claimed that Homo sapiens is the only species that has language, but only recently has it been recognized that humans also have an unusual pattern of growth and development. Social mammals have two stages of pre-adult development: infancy and juvenility. Humans have two additional prolonged and pronounced life history stages: childhood, an interval of four years extending between infancy and the juvenile period that follows, and adolescence, a stage of about eight years that stretches from juvenility to adulthood. We begin by reviewing the primary biological and linguistic changes occurring in each of the four pre-adult ontogenetic stages in human life history. Then we attempt to trace the evolution of childhood and juvenility in our hominin ancestors. We propose that several different forms of selection applied in infancy and childhood; and that, in adolescence, elaborated vocal behaviors played a role in courtship and intrasexual competition, enhancing fitness and ultimately integrating performative and pragmatic skills with linguistic knowledge in a broad faculty of language. A theoretical consequence of our proposal is that fossil evidence of the uniquely human stages may be used, with other findings, to date the emergence of language. If important aspects of language cannot appear until sexual maturity, as we propose, then a second consequence is that the development of language requires the whole of modern human ontogeny. Our life history model thus offers new ways of investigating, and thinking about, the evolution, development, and ultimately the nature of human language.

  18. An ordination of life histories using morphological proxies: capital vs. income breeding in insects.

    Science.gov (United States)

    Davis, Robert B; Javoiš, Juhan; Kaasik, Ants; Õunap, Erki; Tammaru, Toomas

    2016-08-01

    Predictive classifications of life histories are essential for evolutionary ecology. While attempts to apply a single approach to all organisms may be overambitious, recent advances suggest that more narrow ordination schemes can be useful. However, these schemes mostly lack easily observable proxies of the position of a species on respective axes. It has been proposed that, in insects, the degree of capital (vs. income) breeding, reflecting the importance of adult feeding for reproduction, correlates with various ecological traits at the level of among-species comparison. We sought to prove these ideas via rigorous phylogenetic comparative analyses. We used experimentally derived life-history data for 57 species of European Geometridae (Lepidoptera), and an original phylogenetic reconstruction. The degree of capital breeding was estimated based on morphological proxies, including relative abdomen size of females. Applying Brownian-motion-based comparative analyses (with an original update to include error estimates), we demonstrated the associations between the degree of capital breeding and larval diet breadth, sexual size dimorphism, and reproductive season. Ornstein-Uhlenbeck model based phylogenetic analysis suggested a causal relationship between the degree of capital breeding and diet breadth. Our study indicates that the gradation from capital to income breeding is an informative axis to ordinate life-history strategies in flying insects which are affected by the fecundity vs. mobility trade off, with the availability of easy to record proxies contributing to its predictive power in practical contexts. © 2016 by the Ecological Society of America.

  19. Intrapopulation genome size variation in D. melanogaster reflects life history variation and plasticity.

    Directory of Open Access Journals (Sweden)

    Lisa L Ellis

    2014-07-01

    Full Text Available We determined female genome sizes using flow cytometry for 211 Drosophila melanogaster sequenced inbred strains from the Drosophila Genetic Reference Panel, and found significant conspecific and intrapopulation variation in genome size. We also compared several life history traits for 25 lines with large and 25 lines with small genomes in three thermal environments, and found that genome size as well as genome size by temperature interactions significantly correlated with survival to pupation and adulthood, time to pupation, female pupal mass, and female eclosion rates. Genome size accounted for up to 23% of the variation in developmental phenotypes, but the contribution of genome size to variation in life history traits was plastic and varied according to the thermal environment. Expression data implicate differences in metabolism that correspond to genome size variation. These results indicate that significant genome size variation exists within D. melanogaster and this variation may impact the evolutionary ecology of the species. Genome size variation accounts for a significant portion of life history variation in an environmentally dependent manner, suggesting that potential fitness effects associated with genome size variation also depend on environmental conditions.

  20. Parental care trade-offs and life-history relationships in insects.

    Science.gov (United States)

    Gilbert, James D J; Manica, Andrea

    2010-08-01

    Insect parental care is extensive and varied, but its life-history implications have never been comparatively tested. Using original and literature data, we tested predictions about egg size, egg number (lifetime fecundity), and body size under different parental care modes across a phylogeny of 287 insect species. Life-history theory and both comparative and intraspecific evidence from ectotherms suggest parental care should select for bigger, fewer eggs, but that allometric scaling of egg size and lifetime fecundity may depend on whether care consists of provisioning (density-dependent offspring survival) or merely guarding (density-independent offspring survival). Against expectation, egg size was indistinguishable among parental care modes, covarying only with body size. This refutes most theory of egg size evolution under parental care. Lifetime fecundity scaled differently depending on parental investment-positively under no care and guarding, as in most ectotherms, but negatively under provisioning. Reproductive allocation in provisioning insects resembled that in mammals and birds, also groups with obligate provisioning. We propose that the metabolic demands of multiple offspring must scale with species body size more steeply than the parent's provisioning capacity, resulting in larger females laying fewer eggs. These patterns lay the groundwork for a more general understanding of parental care and life history.

  1. Phenoloxidase activity in the infraorder Isoptera: unraveling life-history correlates of immune investment

    Science.gov (United States)

    Rosengaus, Rebeca B.; Reichheld, Jennifer L.

    2016-02-01

    Within the area of ecological immunology, the quantification of phenoloxidase (PO) activity has been used as a proxy for estimating immune investment. Because termites have unique life-history traits and significant inter-specific differences exist regarding their nesting and foraging habits, comparative studies on PO activity can shed light on the general principles influencing immune investment against the backdrop of sociality, reproductive potential, and gender. We quantified PO activity across four termite species ranging from the phylogenetically basal to the most derived, each with their particular nesting/foraging strategies. Our data indicate that PO activity varies across species, with soil-dwelling termites exhibiting significantly higher PO levels than the above-ground wood nester species which in turn have higher PO levels than arboreal species. Moreover, our comparative approach suggests that pathogenic risks can override reproductive potential as a more important driver of immune investment. No gender-based differences in PO activities were recorded. Although termite PO activity levels vary in accordance with a priori predictions made from life-history theory, our data indicate that nesting and foraging strategies (and their resulting pathogenic pressures) can supersede reproductive potential and other life-history traits in influencing investment in PO. Termites, within the eusocial insects, provide a unique perspective for inferring how different ecological pressures may have influenced immune function in general and their levels of PO activity, in particular.

  2. Impact of landfill liner time-temperature history on the service life of HDPE geomembranes.

    Science.gov (United States)

    Rowe, R Kerry; Islam, M Z

    2009-10-01

    The observed temperatures in different landfills are used to establish a number of idealized time-temperature histories for geomembrane liners in municipal solid waste (MSW) landfills. These are then used for estimating the service life of different HDPE geomembranes. The predicted antioxidant depletion times (Stage I) are between 7 and 750 years with the large variation depending on the specific HDPE geomembrane product, exposure conditions, and most importantly, the magnitude and duration of the peak liner temperature. The higher end of the range corresponds to data from geomembranes aged in simulated landfill liner tests and a maximum liner temperature of 37 degrees C. The lower end of the range corresponds to a testing condition where geomembranes were immersed in a synthetic leachate and a maximum liner temperature of 60 degrees C. The total service life of the geomembranes was estimated to be between 20 and 3300 years depending on the time-temperature history examined. The range illustrates the important role that time-temperature history could play in terms of geomembrane service life. The need for long-term monitoring of landfill liner temperature and for geomembrane ageing studies that will provide improved data for assessing the likely long-term performance of geomembranes in MSW landfills are highlighted.

  3. Quantifying the life-history response to increased male exposure in female Drosophila melanogaster.

    Science.gov (United States)

    Edward, Dominic A; Fricke, Claudia; Gerrard, Dave T; Chapman, Tracey

    2011-02-01

    Precise estimates of costs and benefits, the fitness economics, of mating are of key importance in understanding how selection shapes the coevolution of male and female mating traits. However, fitness is difficult to define and quantify. Here, we used a novel application of an established analytical technique to calculate individual- and population-based estimates of fitness-including those sensitive to the timing of reproduction-to measure the effects on females of increased exposure to males. Drosophila melanogaster females were exposed to high and low frequencies of contact with males, and life-history traits for each individual female were recorded. We then compared different fitness estimates to determine which of them best described the changes in life histories. We predicted that rate-sensitive estimates would be more accurate, as mating influences the rate of offspring production in this species. The results supported this prediction. Increased exposure to males led to significantly decreased fitness within declining but not stable or increasing populations. There was a net benefit of increased male exposure in expanding populations, despite a significant decrease in lifespan. The study shows how a more accurate description of fitness, and new insights can be achieved by considering individual life-history strategies within the context of population growth. © 2010 The Author(s). Evolution© 2010 The Society for the Study of Evolution.

  4. Intrapopulation Genome Size Variation in D. melanogaster Reflects Life History Variation and Plasticity

    Science.gov (United States)

    Ellis, Lisa L.; Huang, Wen; Quinn, Andrew M.; Ahuja, Astha; Alfrejd, Ben; Gomez, Francisco E.; Hjelmen, Carl E.; Moore, Kristi L.; Mackay, Trudy F. C.; Johnston, J. Spencer; Tarone, Aaron M.

    2014-01-01

    We determined female genome sizes using flow cytometry for 211 Drosophila melanogaster sequenced inbred strains from the Drosophila Genetic Reference Panel, and found significant conspecific and intrapopulation variation in genome size. We also compared several life history traits for 25 lines with large and 25 lines with small genomes in three thermal environments, and found that genome size as well as genome size by temperature interactions significantly correlated with survival to pupation and adulthood, time to pupation, female pupal mass, and female eclosion rates. Genome size accounted for up to 23% of the variation in developmental phenotypes, but the contribution of genome size to variation in life history traits was plastic and varied according to the thermal environment. Expression data implicate differences in metabolism that correspond to genome size variation. These results indicate that significant genome size variation exists within D. melanogaster and this variation may impact the evolutionary ecology of the species. Genome size variation accounts for a significant portion of life history variation in an environmentally dependent manner, suggesting that potential fitness effects associated with genome size variation also depend on environmental conditions. PMID:25057905

  5. Can family risk-factors moderate the link between psychopathy and life-history strategy?

    Directory of Open Access Journals (Sweden)

    Međedović Janko

    2016-01-01

    Full Text Available Life History Theory is an explanatory evolutionary framework which explains differences in fitness-relevant outcomes using the characteristics of the environment and individual organisms. Basically, individuals can be positioned somewhere on the r/K continuum of the Life History Strategy (LHS: a K or slow strategy represents later maturity and reproduction, a smaller number of offspring with higher investment in them, while the r (or fast strategy follows the opposite pattern. Previous research offered evidence that psychopathy can represent a trait associated with fast LHS. In the present research we examined the relations between the family risk-factors, a four-factor model of psychopathy and the LHS in a sample of male convicts (N=181. The results have shown that a manipulative and deceitful interpersonal style is associated with slow LHS while shallow affect and antisocial tendencies are related to fast LHS. The interactions between psychopathy and family risk-factors revealed that parental criminal behaviour enhances the relation between fast LHS and psychopathic traits, including the manipulative interpersonal style. The findings are in accordance with the Life History Theory and provide a deeper understanding of the preservation of psychopathy in contemporary populations.

  6. Frendship, diversity and fear: young people’s life views and life values in a multicultural society

    Directory of Open Access Journals (Sweden)

    Gunnar J. Gunnarsson

    2015-08-01

    Full Text Available This article introduces initial findings from a study on young people‘s (18 years and older life views and life values in Iceland. The research project is located within a broad theoretical framework and uses interdisciplinary approaches of religious education, multicultural studies and pedagogy. Methodological approaches are both quantitative and qualitative. The first part of the research is a survey which was conducted among altogether 904 students in seven upper secondary schools in the Reykjavík area and other areas of Iceland in 2011 and 2012. In addition to covering measures of background variables and religious affiliations, statements in the survey included themes such as views of life, self-understanding, relation to others, values and value judgments, religions, and diversity and social change. The article focuses especially on findings from the survey related to friendship, attitudes towards diversity, fear and insecurity in a multicultural society. The findings indicate that the participants generally have positive attitudes towards diversity. The majority of participants find it inspiring to have friends of different origins and find it important to respect different cultural and religious traditions. The majority of participants also have strong opinions against racism and bullying. Friends are important and most of the participants are of the opinion that friends are one of the things that provide security. At the same time only a minority is afraid of being unpopular, losing the confidence of their friends or being bullied. But when the fear is about disgracing oneself or about not being able to meet the requirements at school the proportion is higher. Although the economic crisis in Iceland seems to have an effect on the life of the young people answering the survey, most of them are of the opinion that the future holds a lot of opportunities. The results are useful for further discussions on young people´s life views, self

  7. Temperature effects on gametophyte life-history traits and geographic distribution of two cryptic kelp species.

    Directory of Open Access Journals (Sweden)

    L Valeria Oppliger

    Full Text Available A major determinant of the geographic distribution of a species is expected to be its physiological response to changing abiotic variables over its range. The range of a species often corresponds to the geographic extent of temperature regimes the organism can physiologically tolerate. Many species have very distinct life history stages that may exhibit different responses to environmental factors. In this study we emphasized the critical role of the haploid microscopic stage (gametophyte of the life cycle to explain the difference of edge distribution of two related kelp species. Lessonia nigrescens was recently identified as two cryptic species occurring in parapatry along the Chilean coast: one located north and the other south of a biogeographic boundary at latitude 29-30°S. Six life history traits from microscopic stages were identified and estimated under five treatments of temperature in eight locations distributed along the Chilean coast in order to (1 estimate the role of temperature in the present distribution of the two cryptic L. nigrescens species, (2 compare marginal populations to central populations of the two cryptic species. In addition, we created a periodic matrix model to estimate the population growth rate (λ at the five temperature treatments. Differential tolerance to temperature was demonstrated between the two species, with the gametophytes of the Northern species being more tolerant to higher temperatures than gametophytes from the south. Second, the two species exhibited different life history strategies with a shorter haploid phase in the Northern species contrasted with considerable vegetative growth in the Southern species haploid stage. These results provide strong ecological evidence for the differentiation process of the two cryptic species and show local adaptation of the life cycle at the range limits of the distribution. Ecological and evolutionary implications of these findings are discussed.

  8. Life histories of female elementary teachers and their science/teacher role construction

    Science.gov (United States)

    Ramseur, Aletha Johnson

    The research conducted in this study focuses on life histories of female elementary teachers and their science/teacher role construction. Identity theorists argue that the self consists of a collection of identities founded on occupying a particular role. Who we are depends on the roles we occupy. These roles are often referred to as "role identities". In the case of these participants, many role identities (mother, wife, sibling, and teacher) exist. This study focuses primarily on their (science) teacher role identity. Literature on women's lives, as learners and teachers, suggest that women's experiences, currently and throughout history influenced their teacher role construction. There is however, little knowledge of women's lives as elementary teachers of science and the affect of their experiences, currently and throughout history, on their (science) teacher identity construction. Schools delineated by race, class, and gender relations, are similar to other sectors of society's, social and cultural spheres within which race, class, and gender identities are constructed. Using in-depth-interviews female elementary teachers were encouraged to actively reconstruct their life and work-life experiences focusing on family, school and science interactions. They addressed the intellectual and emotional connections between their life and work experiences by focusing on details of their past and present experiences and examining the meaning of those experiences. It was the scrutiny of these connections between their life and work experiences, the meaning derived from them and historical events, and the constraints imposed on their personal choices by broader power relations, such as those of class, race, and gender that informed why we teach, how we teach, and what we teach.

  9. Offshore-onshore linkages in the larval life history of sole in the Gulf of Lions (NW-Mediterranean)

    Science.gov (United States)

    Morat, Fabien; Letourneur, Yves; Blamart, Dominique; Pécheyran, Christophe; Darnaude, Audrey M.; Harmelin-Vivien, Mireille

    2014-08-01

    Understanding individual dispersion from offshore natal areas to coastal nurseries during pelagic larval life is especially important for the sustainable management of exploited marine fish species. For several years, the hatching period, the larval life duration, the average growth rate and the otolith chemical composition (δ13C, δ18O, Sr:Ca and Ba:Ca) during the larval life were studied for young of the year (YOY) of sole collected in three main nurseries of the Gulf of Lions (GoL) (Thau, Mauguio and Berre). We investigated the spatial variation in the origin of the sole larvae which colonised the nurseries around the GoL, and whether temporal differences in environmental conditions during this life stage affected growth and larval life duration. The hatching period ranges from October to March, depending on year and site. Average ages at metamorphosis varied between 43 and 50 days, with the lowest and highest values consistently found for Mauguio and Berre, respectively. Otolith growth rates ranged between 2.7 and 3.2 μm d-1, with the lowest values in Thau and Mauguio and the highest in Berre. Otolith chemical composition during the larval life also varied, suggesting contrasted larval environmental histories in YOY among nurseries. In fishes from Berre and Mauguio, larval life was more influenced by the Rhône River, showing consistently higher larval Ba:Ca ratios (10/23 μmol mol-1) and lower δ13C (-6.5/-6.1‰) and δ18O values (-1.6/0.1‰) than for Thau (with Ba:Ca ratios < 8 μmol mol-1, δ13C ˜-2.3‰ and δ18O ˜1.5‰). Differences in larval otolith composition were observed for 2004, with higher Ba:Ca and lower δ13C and δ18O values than in the two other years. These differences were explained by changes in composition and chemical signatures of water masses after an exceptional flooding event of the Rhône River in late 2003.

  10. A Focus into the Charity "Young Enterprise Northern Ireland" and How Effective Their "Company Programme" Is at Increasing "Life Skills" in Young People

    Science.gov (United States)

    McVeigh, Francis

    2014-01-01

    Purpose - This research project has investigated the "Company Programme" of the charity YE and how effective it is at increasing Life Skills in young people. Data has been obtained using student questionnaires and teacher interviews. Previous studies have been completed on "Life Skills" and "Enterprise Programmes",…

  11. Factors associated with young adults' knowledge regarding family history of Stroke.

    Science.gov (United States)

    Lima, Maria Jose Melo Ramos; Moreira, Thereza Maria Magalhães; Florêncio, Raquel Sampaio; Braga, Predro

    2016-11-21

    to analyze the factors associated with young adults' knowledge regarding family history of stroke. an analytical transversal study, with 579 young adults from state schools, with collection of sociodemographic, clinical and risk factor-related variables, analyzed using logistic regression (backward elimination). a statistical association was detected between age, civil status, and classification of arterial blood pressure and abdominal circumference with knowledge of family history of stroke. In the final logistic regression model, a statistical association was observed between knowledge regarding family history of stroke and the civil status of having a partner (ORa=1.61[1.07-2.42]; p=0.023), abdominal circumference (ORa=0.98[0.96-0.99]; p=0.012) and normal arterial blood pressure (ORa=2.56[1.19-5.52]; p=0.016). an association was observed between socioeconomic factors and risk factors for stroke and knowledge of family history of stroke, suggesting the need for health education or even educational programs on this topic for the clientele in question. analisar os fatores associados ao conhecimento dos adultos jovens sobre histórico familiar de Acidente Vascular Cerebral (AVC). estudo transversal analítico, com 579 adultos jovens de escolas públicas, com coleta de variáveis sociodemográficas, clínicas e de fatores de risco em formulário, analisados utilizando-se regressão logística (backward elimination). detectou-se associação estatística de idade, situação conjugal, classificação da pressão arterial e circunferência abdominal com conhecimento do histórico familiar de AVC. No modelo final de regressão logística, observou-se associação estatística do conhecimento sobre histórico familiar de AVC com situação conjugal com companheiro (ORa=1,61[1,07-2,42]; p=0,023), circunferência abdominal (ORa=0,98[0,96-0,99]; p=0,012) e pressão arterial normal (ORa=2,56[1,19-5,52]; p=0,016). foi constatada associação de fatores socioeconômicos e de

  12. Cultural Differences in Young Adults' Perceptions of the Probability of Future Family Life Events.

    Science.gov (United States)

    Speirs, Calandra; Huang, Vivian; Konnert, Candace

    2017-09-01

    Most young adults are exposed to family caregiving; however, little is known about their perceptions of their future caregiving activities such as the probability of becoming a caregiver for their parents or providing assistance in relocating to a nursing home. This study examined the perceived probability of these events among 182 young adults and the following predictors of their probability ratings: gender, ethnicity, work or volunteer experience, experiences with caregiving and nursing homes, expectations about these transitions, and filial piety. Results indicated that Asian or South Asian participants rated the probability of being a caregiver as significantly higher than Caucasian participants, and the probability of placing a parent in a nursing home as significantly lower. Filial piety was the strongest predictor of the probability of these life events, and it mediated the relationship between ethnicity and probability ratings. These findings indicate the significant role of filial piety in shaping perceptions of future life events.

  13. Blood, sweat and plaster casts: Reviewing the history, composition, and scientific value of the Raymond A. Dart Collection of African Life and Death Masks.

    Science.gov (United States)

    Houlton, T M R; Billings, B K

    2017-10-01

    This paper addresses the history, composition and scientific value of one of the most comprehensive facemask collections in Africa, the Raymond A. Dart Collection of African Life and Death Masks. Housed within the School of Anatomical Sciences at the University of the Witwatersrand (South Africa), it comprises 1110 masks (397 life, 487 death, 226 unknown). Life masks represent populations throughout Africa; death masks predominately southern Africa. Males preponderate by 75%. Recorded ages are error prone, but suggest most life masks are those of <35 year-olds, death masks of 36+ year-olds. A total of 241 masks have associated skeletons, 209 presenting a complete skull. Life masks date between 1927 and c.1980s, death masks 1933 and 1963. This historical collection presents uncanny associations with outmoded typological and evolutionary theories. Once perceived an essential scientific resource, performed craniofacial superimpositions identify the nose as the only stable feature maintained, with the remaining face best preserved in young individuals with minimal body fat. The facemask collection is most viable for teaching and research within the history of science, specifically physical anthropology, and presents some value to craniofacial identification. Future research will have to be conducted with appropriate ethical considerations to science and medicine. Copyright © 2017 Elsevier GmbH. All rights reserved.

  14. Posttraumatic stress disorder: prevalences, comorbidities and quality of life in a community sample of young adults

    OpenAIRE

    Medeiros, Letícia Galery; Silva, Ricardo Azevedo da; Souza, Luciano Dias de Mattos; Silva, Giovanna Del Grande da; Pinheiro, Ricardo Tavares; Jansen, Karen

    2015-01-01

    Objectives To verify the prevalence of current posttraumatic stress disorder (PTSD) in young adults, the occurrence of comorbidities and its association with quality of life. Methods This is a cross-sectional population-based study. The targeted population consisted on individuals aged 18 to 24 years old, who lived in the urban area of Pelotas-RS, Brazil. Cluster sampling was applied. PTSD and its comorbidities were assessed using the Mini International Neuropsychiatric Interview (MINI 5.0), ...

  15. Psychological needs, purpose in life, and problem video game playing among Chinese young adults

    OpenAIRE

    Wu, Anise M. S.; Lei, Lamis L. M.; Ku, L.

    2012-01-01

    The negative impacts of excessive and problematic video game playing on both children and adults are attracting increasing concern. Based on self-determination theory (SDT; Ryan & Deci, 2000), this study hypothesized that the three basic psychological needs of autonomy, competence, and relatedness are positively associated with purpose in life, which in turn acts as a protective factor against problem video game playing among Chinese young adult players. Through a questionnaire survey with a ...

  16. Unequal Burdens of Loss: Examining the Frequency and Timing of Homicide Deaths Experienced by Young Black Men Across the Life Course

    Science.gov (United States)

    2015-01-01

    Objectives. I examined the frequency and developmental timing of traumatic loss resulting from the health disparity of homicide among young Black men in Baltimore, Maryland. Methods. Using a modified grounded theory approach, I conducted in-depth semistructured interviews with 40 Black men (aged 18–24 years) from January 2012 to June 2013. I also constructed adapted life history calendar tools using chronologies of loss, and (1) provided a comprehensive history of loss, (2) determined a specific frequency of homicide deaths, (3) indicated participants’ relationship to the decedents, and (4) identified the developmental timing of deaths. Results. On average, participants knew 3 homicide victims who were overwhelmingly peers. Participant experiences of homicide death started in early childhood, peaked in adolescence, and persisted into emerging adulthood. The traumatic loss of peer homicide was a significant developmental turning point and disrupted participants’ social networks. Conclusions. The traumatic loss of peer homicide was a prevalent life course experience for young Black men and identified the need for trauma- and grief-informed interventions. Future research is needed to examine the physical and psychosocial consequences, coping resources and strategies, and developmental implications of traumatic loss for young Black men in urban contexts. PMID:25905836

  17. Twelve fundamental life histories evolving through allocation-dependent fecundity and survival.

    Science.gov (United States)

    Johansson, Jacob; Brännström, Åke; Metz, Johan A J; Dieckmann, Ulf

    2018-03-01

    An organism's life history is closely interlinked with its allocation of energy between growth and reproduction at different life stages. Theoretical models have established that diminishing returns from reproductive investment promote strategies with simultaneous investment into growth and reproduction (indeterminate growth) over strategies with distinct phases of growth and reproduction (determinate growth). We extend this traditional, binary classification by showing that allocation-dependent fecundity and mortality rates allow for a large diversity of optimal allocation schedules. By analyzing a model of organisms that allocate energy between growth and reproduction, we find twelve types of optimal allocation schedules, differing qualitatively in how reproductive allocation increases with body mass. These twelve optimal allocation schedules include types with different combinations of continuous and discontinuous increase in reproduction allocation, in which phases of continuous increase can be decelerating or accelerating. We furthermore investigate how this variation influences growth curves and the expected maximum life span and body size. Our study thus reveals new links between eco-physiological constraints and life-history evolution and underscores how allocation-dependent fitness components may underlie biological diversity.

  18. Carryover effects of predation risk on postembryonic life-history stages in a freshwater shrimp.

    Science.gov (United States)

    Ituarte, Romina Belén; Vázquez, María Guadalupe; González-Sagrario, María de los Ángeles; Spivak, Eduardo Daniel

    2014-04-01

    For organisms with complex life histories it is well known that risk experienced early in life, as embryos or larvae, may have effects throughout the life cycle. Although carryover effects have been well documented in invertebrates with different levels of parental care, there are few examples of predator-induced responses in externally brooded embryos. Here, we studied the effects of nonlethal predation risk throughout the embryonic development of newly spawned eggs carried by female shrimp on the timing of egg hatching, hatchling morphology, larval development and juvenile morphology. We also determined maternal body mass at the end of the embryonic period. Exposure to predation risk cues during embryonic development led to larger larvae which also had longer rostra but reached the juvenile stage sooner, at a smaller size and with shorter rostra. There was no difference in hatching timing, but changes in larval morphology and developmental timing showed that the embryos had perceived waterborne substances indicative of predation risk. In addition to carryover effects on larval and juvenile stages, predation threat provoked a decrease of body mass in mothers exposed to predator cues while brooding. Our results suggest that risk-exposed embryos were able to recognize the same infochemicals as their mothers, manifesting a response in the free-living larval stage. Thus, future studies assessing anti-predator phenotypes should include embryonic development, which seems to determine the morphology and developmental time of subsequent life-history stages according to perceived environmental conditions. Copyright © 2014 Elsevier GmbH. All rights reserved.

  19. Life history of the sand fly vector Lutzomyia cruciata in laboratory conditions.

    Science.gov (United States)

    Castillo, A; Serrano, A K; Mikery, O F; Pérez, J

    2015-12-01

    Lutzomyia cruciata Coquillet (Diptera: Psychodidae: Phlebotominae) is a potential vector of Leishmania sp.; its geographical distribution in Mexico is widespread, but its life history is unknown. The present study gives relevant information on the life cycle, morphology, survival and reproduction of Lu. cruciata observed over successive generations under laboratory conditions. Seven successive generations were produced. A total of 975 adults were obtained in a sexual proportion of 1.1 : 1 (female : male). Each Lu. cruciata female produced 20.7 eggs and 1.9 adults, approximately, with a proportion of eggs per female of 2.7% (first generation) and 21.3% (second generation). The life cycle of Lu. cruciata, from egg to adult, occurred in 52.7 ± 0.52 days. The largest percentage of mortality occurred during the egg stage (48.5%) and the first larval instar (26.5%), whereas in the pupal stage mortality was the lowest (9.1%). Lutzomyia cruciata exhibits sexual dimorphism based on size, which is exhibited as of the second larval instar, males being smaller than females. The maximum survival of females and males was 10 and 15 days, respectively. An overview of the immature stages of the species made with an electronic scanning microscope is included. This paper contributes basic information on aspects of Lu. cruciata that were previously unknown related to its life history. © 2015 The Royal Entomological Society.

  20. Life skills: evaluation of a theory-driven behavioral HIV prevention intervention for young transgender women.

    Science.gov (United States)

    Garofalo, Robert; Johnson, Amy K; Kuhns, Lisa M; Cotten, Christopher; Joseph, Heather; Margolis, Andrew

    2012-06-01

    Young transgender women are at increased risk for HIV infection due to factors related to stigma/marginalization and participation in risky sexual behaviors. To date, no HIV prevention interventions have been developed or proven successful with young transgender women. To address this gap, we developed and pilot tested a homegrown intervention "Life Skills," addressing the unique HIV prevention needs of young transgender women aged 16-24 years. Study aims included assessing the feasibility of a small group-based intervention with the study population and examining participant's engagement in HIV-related risk behaviors pre- and 3-months-post-intervention. Fifty-one (N = 51) young transgender women enrolled in the study. Our overall attendance and retention rates demonstrate that small group-based HIV prevention programs for young transgender women are both feasible and acceptable. Trends in outcome measures suggest that participation in the intervention may reduce HIV-related risk behaviors. Further testing of the intervention with a control group is warranted.

  1. Seasonal life history trade-offs in two leafwing butterflies: Delaying reproductive development increases life expectancy.

    Science.gov (United States)

    McElderry, Robert M

    2016-04-01

    Surviving inhospitable periods or seasons may greatly affect fitness. Evidence of this exists in the prevalence of dormant stages in the life cycles of most insects. Here I focused on butterflies with distinct seasonal morphological types (not a genetic polymorphism) in which one morphological type, or form, delays reproduction until favorable conditions return, while the other form develops in an environment that favors direct reproduction. For two butterflies, Anaea aidea and A. andria, I tested the hypothesis that the development of each seasonal form involves a differential allocation of resources to survival at eclosion. I assayed differences in adult longevity among summer and winter forms in either a warm, active environment or a cool, calm environment. Winter form adults lived 40 times longer than summer form but only in calm, cool conditions. The magnitude of this difference provided compelling evidence that the winter form body plan and metabolic strategy (i.e. resource conservatism) favor long term survival. This research suggests that winter form adults maintain lowered metabolic rate, a common feature of diapause, to conserve resources and delay senescence while overwintering. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Is continence status associated with quality of life in young children with spina bifida?

    Science.gov (United States)

    Freeman, Kurt A; Smith, Kathryn; Adams, Elizabeth; Mizokawa, Stacey; Neville-Jan, Ann

    2013-01-01

    To evaluate the relationship between child- and parent-reported quality of life (QOL) and bowel and bladder continence among young children with spina bifida (SB). 104 children ages 5-12 years and one of their parents/guardians completed the Pediatric Quality of Life Inventory - Generic Form (PedsQL; parent and child) and the Quality of Life in Spina Bifida Questionnaire (QOLSBQ, parent only). Data on continence, child age, and condition-specific variables were obtained by chart review. Parent and child QOL scores (on all measures of QOL) were positively correlated; parents rated child QOL lower than children's self report. QOL scores did not differ based on continence status. Total PedsQL scores were associated with age and mobility based on child report and with mobility based on parent report. QOL may not be affected by continence status among young children with SB, though demographic (i.e., age) and condition-specific (i.e., functional mobility status) variables appear relevant. Additional research is needed to further evaluate condition-specific variables, other protective variables, and possible measurement issues that influence QOL in young children with SB.

  3. The Impact of Knee Injury History on Health-Related Quality of Life in Adolescent Athletes.

    Science.gov (United States)

    Lam, Kenneth C; Markbreiter, Jessica G

    2017-10-16

    Current evidence suggests that, despite returning to full participation, physically active adults with a previous knee injury experience lower health-related quality of life (HRQOL) than those with no knee injury history. It is unknown if this relationship is present in adolescent athletes. To determine the impact of knee injury history on HRQOL in adolescent athletes who were medically cleared for full participation. Cross-sectional. Athletic training clinics. A convenience sample of 183 adolescent athletes, who were medically cleared for full participation, were grouped by self-report of a previous knee injury: positive knee injury history [HIS] (n=36, age=15.7+1.35 years, height=168.0+11.9 cm; weight=71.8+11.9 kg) and no knee injury history [NO-HIS] (n=147, age=15.5+1.4 years, height=166.0+10.5 cm, weight=67.6+14.6 kg). Participants completed the pediatric version of the International Knee Documentation Committee form (Pedi-IKDC) and Pediatric Quality of Life Inventory (PedsQL) during their preparticipation examination. Generalized linear models were used to compare group differences for the total and subscale scores of the Pedi-IKDC and PedsQL. Main effects of injury group indicated that the HIS group reported significantly lower scores than the NO-HIS group for the Pedi-IKDC total score (p.05). Our findings suggest that, despite returning to full sport participation, adolescent athletes with a previous knee injury generally experience lower HRQOL than their peers with no knee injury history, specifically for knee-specific HRQOL, physical functioning, school functioning and social functioning. Our results are similar to previous findings reported in collegiate athletes and military cadets.

  4. Enablers and challenges of post-16 education and employment outcomes: the perspectives of young adults with a history of SLI.

    Science.gov (United States)

    Carroll, Catherine; Dockrell, Julie

    2012-01-01

    Research studies have begun to investigate the post-16 outcomes for young adults with a specific language impairment (SLI). As yet only tentative conclusions can be drawn with respect to academic and employment outcomes and the factors that are associated with more positive outcomes. Evidence for these findings has relied predominantly on associations between various language, academic and psychosocial assessments. Little attention has been paid to the perspective of the young person. To investigate from the perspective of a group of young people with a history of SLI the factors they believed have enabled and presented a challenge to their post-16 education and employment outcomes and experiences. Nineteen (four female, 15 male) young people aged from 19 to 23 years (average age 21 years), who had all attended the same residential special school for pupils with SLI, were interviewed face to face to explore their views as to what had enabled and limited their transition experiences to date. The data were analysed using thematic analysis. The majority of the young people saw themselves as key agents of change and very active participants in steering their own transition since leaving school. They acknowledged the important role played by their parents and families and how factors such as SLI had affected their transition experiences. The study supports evidence from research with different groups of young people with special educational needs (SEN) and disabilities of the importance of school and post-16 curriculums which develop agency on behalf of the young person. © 2012 Royal College of Speech and Language Therapists.

  5. Phenotypic plasticity in fish life-history traits in two neotropical reservoirs: Petit-Saut Reservoir in French Guiana and Brokopondo Reservoir in Suriname

    Directory of Open Access Journals (Sweden)

    Bernard de Mérona

    Full Text Available Fish species are known for their large phenotypic plasticity in life-history traits in relation to environmental characteristics. Plasticity allows species to increase their fitness in a given environment. Here we examined the life-history response of fish species after an abrupt change in their environment caused by the damming of rivers. Two reservoirs of different age, both situated on the Guiana Shield, were investigated: the young Petit-Saut Reservoir in French Guiana (14 years and the much older Brokopondo Reservoir in Suriname (44 years. Six life-history traits in 14 fish species were studied and compared to their value in the Sinnamary River prior to the completion of Petit-Saut Reservoir. The traits analyzed were maximum length, absolute and relative length at first maturation, proportion of mature oocytes in ripe gonad, batch fecundity and mean size of mature oocytes. The results revealed a general increase of reproductive effort. All species showed a decrease in maximum length. Compared to the values observed before the dam constructions, eight species had larger oocytes and three species showed an increased batch fecundity. These observed changes suggest a trend towards a pioneer strategy. The changes observed in Petit-Saut Reservoir also seemed to apply to the 30 years older Brokopondo Reservoir suggesting that these reservoirs remain in a state of immaturity for a long time.

  6. More or Less Likely to Offend? Young Adults with a History of Identified Developmental Language Disorders

    Science.gov (United States)

    Winstanley, Maxine; Webb, Roger T.; Conti-Ramsden, Gina

    2018-01-01

    Background: There is now substantial literature demonstrating that a disproportionate number of young people who come into contact with youth justice services evidence unidentified language difficulties. These young people, therefore, have received little or no professional input in this area. Conversely, there is a dearth of research pertaining…

  7. Education and Employment Outcomes of Young Adults with a History of Developmental Language Disorder

    Science.gov (United States)

    Conti-Ramsden, Gina; Durkin, Kevin; Toseeb, Umar; Botting, Nicola; Pickles, Andrew

    2018-01-01

    Background: Developmental language disorder (DLD) presents a considerable barrier for young adults to engage in further education and training. Early studies with young adults with DLD revealed poor educational achievement and lack of opportunities to progress in education. More recent studies have provided more positive findings. Relatively…

  8. Increased Symptom Reporting in Young Athletes Based on History of Previous Concussions.

    Science.gov (United States)

    Moser, Rosemarie Scolaro; Schatz, Philip

    2017-01-01

    Research documents increased symptoms in adolescents with a history of two or more concussions. This study examined baseline evaluations of 2,526 younger athletes, ages 10 to 14. Between-groups analyses examined Post Concussion Symptom Scale symptoms by concussion history group (None, One, Two+) and clusters of Physical, Cognitive, Emotional, and Sleep symptoms. Healthy younger athletes with a concussion history reported greater physical, emotional, and sleep-related symptoms than those with no history of concussion, with a greater endorsement in physical/sleep symptom clusters. Findings suggest younger athletes with a history of multiple concussions may experience residual symptoms.

  9. IMPACT OF HATCH-DATE ON EARLY LIFE GROWTH AND SURVIVAL OF MUELLER’S PEARLSIDE (MAUROLICUS MUELLERI) LARVAE, AND LIFE-HISTORY CONSEQUENCES

    KAUST Repository

    Folkvord, Arild; Gundersen, Geir; Albretsen, Jon; Asplin, Lars L; Kaartvedt, Stein; Giske, Jarl

    2015-01-01

    and variable survival due to short term fluctuations in environmental conditions indicate that multiple batch spawning is an adequately evolved life history strategy for marine planktivorous fish such as M. muelleri.

  10. Perceived history of anaphylaxis and parental overprotection, autonomy, anxiety, and depression in food allergic young adults.

    Science.gov (United States)

    Herbert, Linda J; Dahlquist, Lynnda M

    2008-12-01

    This study examined autonomy, anxiety, depression, and perceptions of parental behavior in 86 food allergic young adults and 344 healthy young adults between the ages of 18 and 22. Participants completed an online survey measuring self-reported autonomy, anxiety, depression, and perceptions of parental behavior. Results indicated that, as a group, food allergic young adults did not differ from healthy peers. However, food allergic young adults who reported having experienced an anaphylactic reaction described their disease as more severe, reported more worry about their disease, and rated their parents as more overprotective than food allergic young adults who reported never having experienced anaphylaxis. The experience of anaphylaxis may be a reliable indicator of food allergic individuals who are at risk for psychological distress.

  11. Rapid evolution of parasite life history traits on an expanding range-edge.

    Science.gov (United States)

    Kelehear, Crystal; Brown, Gregory P; Shine, Richard

    2012-04-01

    Parasites of invading species undergoing range advance may be exposed to powerful new selective forces. Low host density in range-edge populations hampers parasite transmission, requiring the parasite to survive longer periods in the external environment before encountering a potential host. These conditions should favour evolutionary shifts in offspring size to maximise parasite transmission. We conducted a common-garden experiment to compare life history traits among seven populations of the nematode lungworm (Rhabdias pseudosphaerocephala) spanning from the parasite population core to the expanding range-edge in invasive cane toads (Rhinella marina) in tropical Australia. Compared to conspecifics from the population core, nematodes from the range-edge exhibited larger eggs, larger free-living adults and larger infective larvae, and reduced age at maturity in parasitic adults. These results support a priori predictions regarding adaptive changes in offspring size as a function of invasion history, and suggest that parasite life history traits can evolve rapidly in response to the selective forces exerted by a biological invasion. © 2012 Blackwell Publishing Ltd/CNRS.

  12. The work life and career development of young breast cancer survivors.

    Science.gov (United States)

    Raque-Bogdan, Trisha L; Hoffman, Mary Ann; Ginter, Amanda C; Piontkowski, Sarah; Schexnayder, Kelci; White, Rachel

    2015-10-01

    Breast cancer survivors represent the largest proportion of cancer survivors, and the rate of young breast cancer survivors who are diagnosed before the age of 40 is increasing. Cancer survivorship scholarship has begun to address many aspects of survivors' quality of life, yet the role of work and career issues have been understudied, particularly for young survivors. To explore the work lives and career development of young breast cancer survivors, this study used consensual qualitative research methodology (Hill, Thompson, & Williams, 1997) to analyze data from qualitative interviews with 13 young women diagnosed with breast cancer before the age of 40. The 4 career-related domains that emerged from the data were (a) cancer-related work challenges, (b) coping with cancer-related work challenges, (c) reappraisal of career development after cancer, and (d) components of career and life satisfaction after cancer. Experiencing breast cancer at a young age was viewed by participants as contributing to an increased desire for work to provide a sense of meaning as well as financial security and insurance. Cancer was further viewed as contributing to lost control over career success and work choices, treatment side effects that interfere with work self-efficacy and capabilities, and interpersonal difficulties connecting within and outside of work. Women with more extensive cancer treatment and side effects reported greater work struggles. Despite this, participants' cancer narratives were characterized by a range of coping strategies, including reframing and seeking control, and by evidence of persistence, resilience, and hope. Implications for research and practice are discussed. (c) 2015 APA, all rights reserved).

  13. Patterns of life events preceding the suicide in rural young Chinese: a case control study.

    Science.gov (United States)

    Zhang, Jie; Ma, Zhenyu

    2012-10-01

    Previous studies on the Chinese suicide found some life events prior to the suicide different from those in the West, but there is a lack of summary of the Chinese life event patterns to better understand the effects of the social structure on Chinese suicide. We tried to identify the life events that precede the Chinese rural youth suicides and compare them with what are found in the West, so as to find the patterns that are particularly true in the Chinese culture contexts. Suicide cases were investigated with a psychological autopsy study in rural China, and local community living controls were also interviewed with the same protocol. We collapsed 64 negative life events into six categories: (1) Marriage/Love, (2) Family/Home, (3) Work/Business, (4) Health/Hospital, (5) Law/Legal, (6) Friend/Relationship. About 92.3% of the suicides studied had experienced at least one type of negative life events. The three most common negative life events categories in the past one year were Family/Home (60.7%), Health/Hospital (53.8%) and Marriage/Love (51.3%) in the rural young suicide victims. Among the negative life events, those related to family relations, love affairs, and marital issues were most likely to precede a suicide of rural suicides in China, and it is especially true of rural young women. Family is an important social institution in rural China for suicide prevention efforts. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Life histories of microalgal species causing harmful blooms: Haploids, diploids and the relevance of benthic stages.

    Science.gov (United States)

    Figueroa, Rosa Isabel; Estrada, Marta; Garcés, Esther

    2018-03-01

    In coastal and offshore waters, Harmful Algal Blooms (HABs) currently threaten the well-being of coastal countries. These events, which can be localized or involve wide-ranging areas, pose risks to human health, marine ecosystems, and economic resources, such as tourism, fisheries, and aquaculture. Dynamics of HABs vary from one site to another, depending on the hydrographic and ecological conditions. The challenge in investigating HABs is that they are caused by organisms from multiple algal classes, each with its own unique features, including different life histories. The complete algal life cycle has been determined in life cycles of bloom-forming species is essential in developing preventative measures. The knowledge obtained thus far has confirmed the complexity of the algal life cycle, which is composed of discrete life stages whose morphology, ecological niche (plankton/benthos), function, and lifespan vary. The factors that trigger transitions between the different stages in nature are mostly unknown, but it is clear that an understanding of this process provides the key to effectively forecasting bloom recurrence, maintenance, and decline. Planktonic stages constitute an ephemeral phase of the life cycle of most species whereas resistant, benthic stages enable a species to withstand adverse conditions for prolonged periods, thus providing dormant reservoirs for eventual blooms and facilitating organismal dispersal. Here we review current knowledge of the life cycle strategies of major groups of HAB producers in marine and brackish waters. Rather than providing a comprehensive discussion, the objective was to highlight several of the research milestones that have changed our understanding of the plasticity and frequency of the different life cycle stages as well as the transitions between them. We also discuss the relevance of benthic and planktonic forms and their implications for HAB dynamics. Copyright © 2018. Published by Elsevier B.V.

  15. Evolution of senescence in nature: physiological evolution in populations of garter snake with divergent life histories.

    Science.gov (United States)

    Robert, Kylie A; Bronikowski, Anne M

    2010-02-01

    Evolutionary theories of aging are linked to life-history theory in that age-specific schedules of reproduction and survival determine the trajectory of age-specific mutation/selection balances across the life span and thus the rate of senescence. This is predicted to manifest at the organismal level in the evolution of energy allocation strategies of investing in somatic maintenance and robust stress responses in less hazardous environments in exchange for energy spent on growth and reproduction. Here we report experiments from long-studied populations of western terrestrial garter snakes (Thamnophis elegans) that reside in low and high extrinsic mortality environments, with evolved long and short life spans, respectively. Laboratory common-environment colonies of these two ecotypes were tested for a suite of physiological traits after control and stressed gestations. In offspring derived from control and corticosterone-treated dams, we measured resting metabolism; mitochondrial oxygen consumption, ATP and free radical production rates; and erythrocyte DNA damage and repair ability. We evaluated whether these aging biomarkers mirrored the evolution of life span and whether they were sensitive to stress. Neonates from the long-lived ecotype (1) were smaller, (2) consumed equal amounts of oxygen when corrected for body mass, (3) had DNA that damaged more readily but repaired more efficiently, and (4) had more efficient mitochondria and more efficient cellular antioxidant defenses than short-lived snakes. Many ecotype differences were enhanced in offspring derived from stress-treated dams, which supports the conclusion that nongenetic maternal effects may further impact the cellular stress defenses of offspring. Our findings reveal that physiological evolution underpins reptilian life histories and sheds light on the connectedness between stress response and aging pathways in wild-dwelling organisms.

  16. Life history tactics shape amphibians' demographic responses to the North Atlantic Oscillation.

    Science.gov (United States)

    Cayuela, Hugo; Joly, Pierre; Schmidt, Benedikt R; Pichenot, Julian; Bonnaire, Eric; Priol, Pauline; Peyronel, Olivier; Laville, Mathias; Besnard, Aurélien

    2017-11-01

    Over the last three decades, climate abnormalities have been reported to be involved in biodiversity decline by affecting population dynamics. A growing number of studies have shown that the North Atlantic Oscillation (NAO) influences the demographic parameters of a wide range of plant and animal taxa in different ways. Life history theory could help to understand these different demographic responses to the NAO. Indeed, theory states that the impact of weather variation on a species' demographic traits should depend on its position along the fast-slow continuum. In particular, it is expected that NAO would have a higher impact on recruitment than on adult survival in slow species, while the opposite pattern is expected occur in fast species. To test these predictions, we used long-term capture-recapture datasets (more than 15,000 individuals marked from 1965 to 2015) on different surveyed populations of three amphibian species in Western Europe: Triturus cristatus, Bombina variegata, and Salamandra salamandra. Despite substantial intraspecific variation, our study revealed that these three species differ in their position on a slow-fast gradient of pace of life. Our results also suggest that the differences in life history tactics influence amphibian responses to NAO fluctuations: Adult survival was most affected by the NAO in the species with the fastest pace of life (T. cristatus), whereas recruitment was most impacted in species with a slower pace of life (B. variegata and S. salamandra). In the context of climate change, our findings suggest that the capacity of organisms to deal with future changes in NAO values could be closely linked to their position on the fast-slow continuum. © 2017 John Wiley & Sons Ltd.

  17. Inequalities of quality of life in unemployed young adults: A population-based questionnaire study

    Directory of Open Access Journals (Sweden)

    Edén Lena

    2007-03-01

    Full Text Available Abstract Background It is well known that unemployment is a great problem both to the exposed individual and to the whole society. Unemployment is reported as more common among young people compared to the general level of unemployment. Inequity in health status and life-satisfaction is related to unemployment. The purpose of this population-based study was to describe QOL among unemployed young people compared to those who are not unemployed, and to analyse variables related to QOL for the respective groups. Methods The sample consisted of 264 young unemployed individuals and 528 working or studying individuals as a reference group. They all received a questionnaire about civil status, educational level, immigration, employment status, self-reported health, self-esteem, social support, social network, spare time, dwelling, economy and personal characteristics. The response rate was 72%. The significance of differences between proportions was tested by Fisher's exact test or by χ2 test. Multivariate analysis was carried out by means of a logistic regression model. Results Our results balance the predominant picture of youth unemployment as a principally negative experience. Although the unemployed reported lower levels of QOL than the reference group, a majority of unemployed young adults reported good QOL, and 24% even experienced higher QOL after being unemployed. Positive QOL related not only to good health, but also to high self-esteem, satisfaction with spare time and broad latitude for decision-making. Conclusion Even if QOL is good among a majority of unemployed young adults, inequalities in QOL were demonstrated. To create more equity in health, individuals who report reduced subjective health, especially anxiety need extra attention and support. Efforts should aim at empowering unemployed young adults by identifying their concerns and resources, and by creating individual programmes in relation not only to education and work, but also

  18. Inequalities of quality of life in unemployed young adults: a population-based questionnaire study.

    Science.gov (United States)

    Axelsson, Lars; Andersson, Ingemar H; Edén, Lena; Ejlertsson, Göran

    2007-03-21

    It is well known that unemployment is a great problem both to the exposed individual and to the whole society. Unemployment is reported as more common among young people compared to the general level of unemployment. Inequity in health status and life-satisfaction is related to unemployment. The purpose of this population-based study was to describe QOL among unemployed young people compared to those who are not unemployed, and to analyse variables related to QOL for the respective groups. The sample consisted of 264 young unemployed individuals and 528 working or studying individuals as a reference group. They all received a questionnaire about civil status, educational level, immigration, employment status, self-reported health, self-esteem, social support, social network, spare time, dwelling, economy and personal characteristics. The response rate was 72%. The significance of differences between proportions was tested by Fisher's exact test or by chi2 test. Multivariate analysis was carried out by means of a logistic regression model. Our results balance the predominant picture of youth unemployment as a principally negative experience. Although the unemployed reported lower levels of QOL than the reference group, a majority of unemployed young adults reported good QOL, and 24% even experienced higher QOL after being unemployed. Positive QOL related not only to good health, but also to high self-esteem, satisfaction with spare time and broad latitude for decision-making. Even if QOL is good among a majority of unemployed young adults, inequalities in QOL were demonstrated. To create more equity in health, individuals who report reduced subjective health, especially anxiety need extra attention and support. Efforts should aim at empowering unemployed young adults by identifying their concerns and resources, and by creating individual programmes in relation not only to education and work, but also to personal development.

  19. Life history comparison of two terrestrial isopods in relation to habitat specialization

    Science.gov (United States)

    Quadros, Aline Ferreira; Caubet, Yves; Araujo, Paula Beatriz

    2009-03-01

    For many animal species, there is a relationship between life history strategies, as predicted by the r- K-selection theory, degree of habitat specialization and response to habitat alteration and loss. Here we compare two sympatric woodlice species with contrasting patterns of habitat use and geographical distribution. We predict that Atlantoscia floridana (Philosciidae), considered a habitat generalist, would exhibit the r-selected traits, whereas Balloniscus glaber (Balloniscidae), considered a habitat specialist, should have the K-selected traits. We analyzed several life history traits as well as life and fecundity tables using 715 and 842 females of A. floridana and B. glaber, respectively, from populations living in syntopy in southern Brazil. As predicted, most evaluated traits allow A. floridana to be considered an r-strategist and B. glaber a K-strategist: A. floridana showed a shorter lifetime, faster development, earlier reproduction, a smaller parental investment, higher net reproductive rate ( R0), a higher growth rate ( r) and a shorter generation time ( T) in comparison to B. glaber. A. floridana seems to be a successful colonizer with a high reproductive output. These characteristics explain its local abundance, commonness and wide geographical distribution. On the contrary, B. glaber has a restricted geographical distribution that is mainly associated with Atlantic forest fragments, a biome threatened by deforestation and replacement by monocultures. Its narrow distribution combined with the K-selected traits may confer to this species an increased extinction risk.

  20. Early parental loss and depression history: associations with recent life stress in major depressive disorder.

    Science.gov (United States)

    Slavich, George M; Monroe, Scott M; Gotlib, Ian H

    2011-09-01

    Although exposure to early adversity and prior experiences with depression have both been associated with lower levels of precipitating life stress in depression, it is unclear whether these stress sensitization effects are similar for all types of stress or whether they are specific to stressors that may be particularly depressogenic, such as those involving interpersonal loss. To investigate this issue, we administered structured, interview-based measures of early adversity, depression history, and recent life stress to one hundred adults who were diagnosed with major depressive disorder. As predicted, individuals who experienced early parental loss or prolonged separation (i.e., lasting one year or longer) and persons with more lifetime episodes of depression became depressed following lower levels of life stress occurring in the etiologically-central time period of three months prior to onset of depression. Importantly, however, additional analyses revealed that these effects were unique to stressors involving interpersonal loss. These data highlight potential stressor-specific effects in stress sensitization and demonstrate for the first time that individuals exposed to early parental loss or separation, and persons with greater histories of MDD, may be selectively sensitized to stressors involving interpersonal loss. Copyright © 2011 Elsevier Ltd. All rights reserved.