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1

Reproductive life-span and sources of mortality for alternative male life-history strategies in  

E-print Network

in sockeye salmon, Oncorhynchus nerka Stephanie M. Carlson, Harry B. Rich, Jr., and Thomas P. Quinn Abstract-killed, stranded), and reproductive life-span of male sockeye salmon, Oncorhynchus nerka (Walbaum in Artedi, 1792 par les goélands, échouage) et la durée de la vie reproductive de saumons rouges, Oncorhynchus nerka

Carlson, Stephanie

2

Experimental Evolution Reveals Antagonistic Pleiotropy in Reproductive Timing but Not Life Span in Caenorhabditis elegans  

PubMed Central

Many mutations that dramatically extend life span in model organisms come with substantial fitness costs. Although these genetic manipulations provide valuable insight into molecular modulators of life span, it is currently unclear whether life-span extension is unavoidably linked to fitness costs. To examine this relationship, we evolved a genetically heterogeneous population of Caenorhabditis elegans for 47 generations, selecting for early fecundity. We asked whether an increase in early fecundity would necessitate a decrease in longevity or late fecundity (antagonistic pleiotropy). Caenorhabditis elegans experimentally evolved for increased early reproduction and decreased late reproduction but suffered no total fitness or life-span costs. Given that antagonistic pleiotropy among these traits has been previously demonstrated in some cases, we conclude that the genetic constraint is not absolute, that is, it is possible to uncouple longevity from early fecundity using genetic variation segregating within and among natural populations. PMID:21975091

Anderson, Jennifer L.; Reynolds, Rose M.; Morran, Levi T.; Tolman-Thompson, Julie

2011-01-01

3

Determination of the cost of worker reproduction via diminished life span in the ant Diacamma sp.  

PubMed

Workers of social Hymenoptera can usually produce male offspring, but rarely do so in the presence of a queen despite the potential individual fitness benefit. Various mechanisms have been hypothesized to regulate worker reproduction, including avoiding the colony-level cost of worker reproduction. However, firm quantitative evidence is lacking to support that hypothesis. Here, we accurately quantified this cost by studying an ant species (Diacamma sp.) in which worker reproduction is rare in the presence of the gamergate (the functional queen). A series of experiments to manipulate worker-gamergate contact revealed that short-term brood-production efficiency is not changed by the presence of worker reproduction. However, when workers reproduce, their average life span is reduced to between 74% and 88% of that in the absence of reproduction, indicating a long-term cost to the colony. In theory, this cost can explain the policing of worker reproduction under a queen-single mating system, but the cost does not appear to be high enough to stop worker reproduction. When contact with the gamergate is lost, it is only the nonreproductive workers whose life span was reduced; the reproductive workers lived as long as nonorphaned workers. We suggest that an increased workload can account for the reduction in life span better than a trade-off between reproduction and longevity. PMID:22519774

Tsuji, Kazuki; Kikuta, Noritsugu; Kikuchi, Tomonori

2012-05-01

4

Effect of temperature on laboratory growth, reproduction and life span of Octopus bimaculoides  

Microsoft Academic Search

Laboratory culture of 40 Octopus bimaculoides from April 1982 to August 1983 through the full life cycle at 18C vs 23C provided information on the growth, reproductive biology and life span of this California littoral octopus. At 18C, the cephalopods grew from a hatchling size of 0.07 g to a mean of 619 g in 404 d; the largest individual

J. W. Forsythe; R. T. Hanlon

1988-01-01

5

Age at Menopause, Reproductive Life Span, and Type 2 Diabetes Risk  

PubMed Central

OBJECTIVE Age at menopause is an important determinant of future health outcomes, but little is known about its relationship with type 2 diabetes. We examined the associations of menopausal age and reproductive life span (menopausal age minus menarcheal age) with diabetes risk. RESEARCH DESIGN AND METHODS Data were obtained from the InterAct study, a prospective case-cohort study nested within the European Prospective Investigation into Cancer and Nutrition. A total of 3,691 postmenopausal type 2 diabetic case subjects and 4,408 subcohort members were included in the analysis, with a median follow-up of 11 years. Prentice weighted Cox proportional hazards models were adjusted for age, known risk factors for diabetes, and reproductive factors, and effect modification by BMI, waist circumference, and smoking was studied. RESULTS Mean (SD) age of the subcohort was 59.2 (5.8) years. After multivariable adjustment, hazard ratios (HRs) of type 2 diabetes were 1.32 (95% CI 1.041.69), 1.09 (0.901.31), 0.97 (0.861.10), and 0.85 (0.701.03) for women with menopause at ages <40, 4044, 4549, and ?55 years, respectively, relative to those with menopause at age 5054 years. The HR per SD younger age at menopause was 1.08 (1.021.14). Similarly, a shorter reproductive life span was associated with a higher diabetes risk (HR per SD lower reproductive life span 1.06 [1.011.12]). No effect modification by BMI, waist circumference, or smoking was observed (P interaction all > 0.05). CONCLUSIONS Early menopause is associated with a greater risk of type 2 diabetes. PMID:23230098

Brand, Judith S.; van der Schouw, Yvonne T.; Onland-Moret, N. Charlotte; Sharp, Stephen J.; Ong, Ken K.; Khaw, Kay-Tee; Ardanaz, Eva; Amiano, Pilar; Boeing, Heiner; Chirlaque, Maria-Dolores; Clavel-Chapelon, Franoise; Crowe, Francesca L.; de Lauzon-Guillain, Blandine; Duell, Eric J.; Fagherazzi, Guy; Franks, Paul W.; Grioni, Sara; Groop, Leif C.; Kaaks, Rudolf; Key, Timothy J.; Nilsson, Peter M.; Overvad, Kim; Palli, Domenico; Panico, Salvatore; Quirs, J. Ramn; Rolandsson, Olov; Sacerdote, Carlotta; Snchez, Mara-Jos; Slimani, Nadia; Teucher, Birgit; Tjonneland, Anne; Tumino, Rosario; van der A, Daphne L.; Feskens, Edith J.M.; Langenberg, Claudia; Forouhi, Nita G.; Riboli, Elio; Wareham, Nicholas J.

2013-01-01

6

Life-span extension by caloric restriction is determined by type and level of food reduction and by reproductive mode in Brachionus manjavacas (Rotifera).  

PubMed

We measured life span and fecundity of three reproductive modes in a clone of the monogonont rotifer Brachionus manjavacas subjected to chronic caloric restriction (CCR) over a range of food concentrations or to intermittent fasting (IF). IF increased life span 50%-70% for all three modes, whereas CCR increased life span of asexual females derived from sexually or asexually produced eggs, but not that of sexual females. The main effect of CR on both asexual modes was to delay death at young ages, rather than to prevent death at middle ages or to greatly extend maximum life span; in contrast CR in sexual females greatly increased the life span of a few long-lived individuals. Lifetime fecundity did not decrease with CCR, suggesting a lack of resource allocation trade-off between somatic maintenance and reproduction. Multiple outcomes for a clonal lineage indicate that different responses are established through epigenetic programming, whereas differences in life-span allocations suggest that multiple genetic mechanisms mediate life-span extension. PMID:22904096

Gribble, Kristin E; Welch, David B Mark

2013-04-01

7

Reproductive life-span and sources of mortality for alternative male life-history strategies in sockeye salmon, Oncorhynchus nerka  

Microsoft Academic Search

Abstract: In anadromous salmonid fishes, a fraction of the males (jacks) spend fewer years at sea than females and most males in the population. It has been hypothesized,that the higher survival rates of jacks at sea are balanced,by their reduced reproductive success. One component of reproductive success is in-stream longevity, and jacks were re- ported to have a shorter reproductive

Stephanie M. Carlson; Thomas P. Quinn

2004-01-01

8

Time scale matters: genetic analysis does not support adaptation-by-time as the mechanism for adaptive seasonal declines in kokanee reproductive life span.  

PubMed

Seasonal declines of fitness-related traits are often attributed to environmental effects or individual-level decisions about reproductive timing and effort, but genetic variation may also play a role. In populations of Pacific salmon (Oncorhynchus spp.), seasonal declines in reproductive life span have been attributed to adaptation-by-time, in which divergent selection for different traits occurs among reproductively isolated temporal components of a population. We evaluated this hypothesis in kokanee (freshwater obligate Oncorhynchus nerka) by testing for temporal genetic structure in neutral and circadian-linked loci. We detected no genetic differences in presumably neutral loci among kokanee with different arrival and maturation dates within a spawning season. Similarly, we detected no temporal genetic structure in OtsClock1b, Omy1009uw, or OmyFbxw11, candidate loci associated with circadian function. The genetic evidence from this study and others indicates a lack of support for adaptation-by-time as an important evolutionary mechanism underlying seasonal declines in reproductive life span and a need for greater consideration of other mechanisms such as time-dependent, adaptive adjustment of reproductive effort. PMID:25478160

Morbey, Yolanda E; Jensen, Evelyn L; Russello, Michael A

2014-09-01

9

My Reproductive Life Plan  

MedlinePLUS

... Button Information For... Media Policy Makers My Reproductive Life Plan Language: English Espaol (Spanish) Share Compartir Thinking ... to achieve those goals is called a reproductive life plan . There are many kinds of reproductive life ...

10

Effects of salinity on survival, growth, reproductive and life span characteristics of Artemia populations from Urmia Lake and neighboring lagoons.  

PubMed

This study deals with effects of different salinities on the survival, growth, reproductive and lifespan characteristics of three Artemia populations from Urmia Lake and small lagoons at the vicinity of the lake under laboratory conditions. Experimental salinities ranged from 75 to 175 g L(-1). Salinity was proved to have significant impact on the majority of the characters studied in this survey. Growth and survival in bisexual A. urmiana and parthenogenetic Artemia from Lake Urmia were significantly higher with respect to the parthenogenetic Artemia from lagoons at most of the salinities tested. Reproductive characteristics such as total number of broods, total offspring number of offspring in each brood and number of offspring at each day of reproductive period reduced with increasing salinity. Moreover higher salinity prolonged the prereproductive period but shortened the total reproductive period. Higher salinities also affected the percentage of encystment and post-reproductive period, showing significantly higher values in parthenogenetic populations in comparison to bisexual A. urmiana. PMID:18817185

Agh, N; Van Stappen, G; Bossier, P; Sepehri, H; Lotfi, V; Rouhani, S M Razavi; Sorgeloos, P

2008-01-15

11

Insulin signaling and life span  

Microsoft Academic Search

Hyperinsulinemia and metabolic diseases are known to be associated with a reduction in life span. In the presence of insulin\\u000a resistance, insulin signaling is selectively impaired, contributing to longevity shortening. Insulin indeed activates a complex\\u000a web of intracellular downstream pathways, which are involved in mechanisms regulating longevity, primarily affecting cellular\\u000a proliferation and apoptosis. Insulin resistance promotes reactive oxygen species (ROS)

Angelo Avogaro; Saula Vigili de Kreutzenberg; Gian Paolo Fadini

2010-01-01

12

Developing a reproductive life plan.  

PubMed

The purpose of this article is 2-fold: to emphasize the importance of a reproductive life plan and to define its key elements. We review the 2006 recommendations from the Centers for Disease Control and Prevention (CDC) regarding ways to improve the delivery of preconception health care to women in the United States, with particular focus on encouraging individual reproductive responsibility throughout the life span and on encouraging every woman to develop a reproductive life plan. We propose recommendations for the content of a reproductive life plan and explore ways to incorporate the guidelines from the CDC into clinical practice. By encouraging women to consider their plans for childbearing before they become pregnant, clinicians have the opportunity to influence behavior before pregnancy, which may decrease the incidence of unintended pregnancies and adverse pregnancy outcomes. PMID:23181644

Files, Julia A; Frey, Keith A; David, Paru S; Hunt, Katherine S; Noble, Brie N; Mayer, Anita P

2011-01-01

13

Genetic (Co)Variation for Life Span in Rhabditid Nematodes: Role of Mutation, Selection, and History  

PubMed Central

The evolutionary mechanisms maintaining genetic variation in life span, particularly post-reproductive life span, are poorly understood. We characterized the effects of spontaneous mutations on life span in the rhabditid nematodes Caenorhabditis elegans and C. briggsae and standing genetic variance for life span and correlation of life span with fitness in C. briggsae. Mutations decreased mean life span, a signature of directional selection. Mutational correlations between life span and fitness were consistently positive. The average selection coefficient against new mutations in C. briggsae was approximately 2% when homozygous. The pattern of phylogeographic variation in life span is inconsistent with global mutationselection balance (MSB), but MSB appears to hold at the local level. Standing genetic correlations in C. briggsae reflect mutational correlations at a local scale but not at a broad phylogeographic level. At the local scale, results are broadly consistent with predictions of the mutation accumulation hypothesis for the evolution of aging. PMID:19671885

Upadhyay, Ambuj; Salomon, Matthew P.; Grigaltchik, Veronica; Baer, Charles F.

2009-01-01

14

What You Should Know about Your Reproductive Time Span  

MedlinePLUS

WHATYOUSHOULDKNOWABOUT Your Reproductive Time Span S ocial norms have changed over the past few decades as women are delaying marriage, choosing not to marry, post- poning childbearing, or having their ...

15

Neutrophil life span in paroxysmal nocturnal hemoglobinuria.  

PubMed

We have studied neutrophil intravascular life span in six patients with paroxysmal nocturnal hemoglobinuria (PNH); four had normal neutrophil counts when studied and two were neutropenic. Five patients had enough circulating neutrophils to isolate for tests in vitro. Lysis of labeled neutrophils was greatly increased, compared to that of normal volunteers, when these neutrophils were incubated with acidified fresh serum as a source of active complement plus serum containing antineutrophil antibodies (from three different sources). Despite the in vitro lesion, however, each of these patients had a normal neutrophil intravascular life span as measured by the 32P-diisopropylfluorophosphate technique. One neutropenic patient, who had a normal neutrophil life span, had a shift of cells from the circulating to marginated pool of sufficient degree to cause the neutropenia. A second (severely) neutropenic patient was found to have developed extreme marrow hypoplasia, also explaining the neutropenia. Thus, in contrast to the shortened red cell life span, we have been unable to find a shortened neutrophil life span in PNH. PMID:901939

Brubaker, L H; Essig, L J; Mengel, C E

1977-10-01

16

Extraordinary long life spans in fruit-feeding butterflies can provide window on evolution of life span and aging  

PubMed Central

Information on the life span of organisms in the field is essential for elucidating the evolution of life span and aging. We present mark-recapture data (>30 000 marked individuals, >4000 recaptured at least once) on forty-seven species of fruit-feeding butterflies in a tropical forest in Uganda. The data reveal adult life spans in the field for several species that are significantly longer than previously recorded in Lepidoptera (butterflies and moths). Longevity records for species of which more than 100 individuals were recaptured ranged from 67 (Bicyclus auricruda) to 293 days (Euphaedra medon). In contrast to the majority of Lepidoptera which are short-lived, these all show exceptionally long life spans, and may thus help to better identify factors that affect aging, particularly when combined with information on temporal patterns in reproduction, strategies to avoid predation, and nutritional ecology. These key traits are readily measurable in butterflies and thus studies on fruit-feeding butterflies have much potential for gaining insight into the evolution of life span and aging, especially given the tradition of field-research on butterflies. PMID:17360139

Molleman, F.; Zwaan, B. J.; Brakefield, P.M.; Carey, J. R.

2007-01-01

17

Update in Female Reproduction: A Life-Cycle Approach  

Microsoft Academic Search

Context: Female reproduction spans a developmental life arc from fetal life and childhood, through puberty to the reproductive years, and, finally, ovarian follicle depletion and the onset of menopause. Objective: This invited review highlights a selection of reports from leading journals over the past 2 yr that have significantly advanced our understanding of female reproduction from conception to menopause. Synthesis:

Robert L. Barbieri

18

Sensorimotor Synchronization across the Life Span  

ERIC Educational Resources Information Center

The present study investigates the contribution of general processing resources as well as other more specific factors to the life-span development of sensorimotor synchronization and its component processes. Within a synchronization tapping paradigm, a group of 286 participants, 6 to 88 years of age, were asked to synchronize finger taps with

Drewing, Knut; Aschersleben, Gisa; Li, Shu-Chen

2006-01-01

19

Extending life span by increasing oxidative stress  

Microsoft Academic Search

Various nutritional, behavioral, and pharmacological interventions have been previously shown to extend life span in diverse model organisms, including Saccharomyces cerevisiae, Caenorhabditis elegans, Drosophila melanogaster, mice, and rats, as well as possibly monkeys and humans. This review aims to summarize published evidence that several longevity-promoting interventions may converge by causing an activation of mitochondrial oxygen consumption to promote increased formation

Michael Ristow; Sebastian Schmeisser

2011-01-01

20

Career development: a life span issue.  

PubMed

One of the challenges for individuals pursuing a career throughout their life span is how to maintain a high level of professional competence. As the composition of the workforce changes, and new technologies are developed, workers are faced with changing job demands and pressures. A major issue for the 1990s is how long a worker's skills will remain current. With rapid technological changes, workers may find it necessary to update continually their knowledge, skills, and abilities or risk becoming obsolete. Factors such as individuals' motivation and attitudes and organizational climate can contribute to choices regarding career development. Current research on the factors that contribute to career development activities is reviewed, along with the impact of multiple career transitions throughout the life span. Interventions such as retraining and outplacement, which allow individuals in later life to continue work, change jobs, and further develop their careers, are also discussed. PMID:7843212

Sterns, H L; Dorsett, J G

1994-01-01

21

Extending Cellular Life-Span with Telomerase  

NSDL National Science Digital Library

This Science magazine site contains full text of a research article: "Extension of Life-Span by Introduction of Telomerase into Normal Human Cells," by Andrea G. Bodnar et. al. (January 16, 1998; Vol 279, No. 5349--available in Adobe Acrobat [.pdf] format only) describes the Telomerase finding and includes a commentary by Titia de Lange of Rockefeller University's Laboratory of Cell Biology and Genetics. There has been a recent finding regarding telomerase, a gene which affects the mechanisms controlling human cell replication. The site above provides general information on telomerase, current telomere research, and the use of telemorase in medical practice. Telomerase increases the life-span of a cell, and is thus central to both aging and cancer.

Bodnar, Andrea G.; Chiu, Choy-Pik.; Frolkis, Maria.; Harley, Calvin B.; Holt, Shawn E.; Lichtsteiner, Serge.

1997-01-01

22

Spatial abilities across the adult life span.  

PubMed

The study investigates age-related effects across the adult life span on spatial abilities (testing subabilities based on a distinction between spatial visualization, mental rotation, and perspective taking) and spatial self-assessments. The sample consisted of 454 participants (223 women and 231 men) from 20 to 91 years of age. Results showed nonlinear age-related effects for spatial visualization and perspective taking but linear effects for mental rotation; few or no age-related effects were found for spatial self-assessments. Working memory accounted for only a small proportion of the variance in all spatial tasks and had no effect on spatial self-assessments. Overall, our findings suggest that the influence of age on spatial skills across the adult life span is considerable, but the effects of age change as a function of the spatial task considered, and the effect on spatial self-assessment is more marginal. PMID:23895173

Borella, Erika; Meneghetti, Chiara; Ronconi, Lucia; De Beni, Rossana

2014-02-01

23

The Complex Genetic Architecture of Drosophila Life Span  

E-print Network

the genetic basis of variation in aging and life span. Understanding how these interactions in¯uence the rate for dissecting the complex genetic architecture underlying aging and life span limitation in the foreseeable future. Two general approaches have been used to study the genetic basis of aging and life span

Mackay, Trudy F.C.

24

78. VIEW SHOWING PLACEMENT OF LIFE SPAN SHOE ON PIER ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

78. VIEW SHOWING PLACEMENT OF LIFE SPAN SHOE ON PIER 6, LOOKING NORTH, March 5, 1935 - Sacramento River Bridge, Spanning Sacramento River at California State Highway 275, Sacramento, Sacramento County, CA

25

A Motivational Theory of Life-Span Development  

ERIC Educational Resources Information Center

This article had four goals. First, the authors identified a set of general challenges and questions that a life-span theory of development should address. Second, they presented a comprehensive account of their Motivational Theory of Life-Span Development. They integrated the model of optimization in primary and secondary control and the

Heckhausen, Jutta; Wrosch, Carsten; Schulz, Richard

2010-01-01

26

Developmental Regulation across the Life Span: Toward a New Synthesis  

ERIC Educational Resources Information Center

How can individuals regulate their own development to live happy, healthy, and productive lives? Major theories of developmental regulation across the life span have been proposed (e.g., dual-process model of assimilation and accommodation; motivational theory of life-span development; model of selection, optimization, and compensation), but they

Haase, Claudia M.; Heckhausen, Jutta; Wrosch, Carsten

2013-01-01

27

Boundaries of life: estimating the life span of the biosphere  

NASA Astrophysics Data System (ADS)

We present a minimal model for the global carbon cycle of the Earth containing the reservoirs mantle ocean floor continental crust continental biosphere and the Kerogen as well as the aggregated reservoir ocean and atmosphere and obtain reasonable values for the present distribution of carbon in the surface reservoirs of the Earth The Earth system model for the long-term carbon cycle is specified by introducing three different types of biosphere prokaryotes eucaryotes and complex multicellular life They are characterized by different global temperature tolerance windows prokaryotes 2oC 100oC eucaryotes 5oC 45oC complex multicellular life 0oC 30oC From the Archaean to the future there always exists a prokaryotic biosphere 2 Gyr ago eucaryotic life first appears because the global surface temperature reaches the tolerance window for eucaryotes The emergence of complex multicellular life is connected with an explosive increase in biomass and a strong decrease in Cambrian global surface temperature at about 0 54 Gyr ago In the long-term future the three types of biosphere will die out in reverse sequence of their appearance For realistic values of the biotic enhancement of weathering there is no bistability in the future solutions for complex life Therefore complex organisms will not extinct by an implosion in comparison to the Cambrian explosion Eucaryotes and complex life become extinct because of too high surface temperatures in the future The ultimate life span of the biosphere is defined by the extinction of procaryotes in about 1 6 Gyr

Franck, S.; Bounama, C.; von Bloh, W.

28

Ectopic expression of telomerase safely increases health span and life span.  

PubMed

The absence of telomerase from somatic cells of mammals has significant consequences for aging. First, it limits the number of potential cell divisions and in so doing sets limits on both life span and cancer cell proliferation. Second, shortened telomeres are known to result in physiological dysfunction, including playing a role in human diseases such as Werner syndrome and ataxia telangiectasia. Ectopic expression of the catalytic subunit of telomerase, telomerase reverse transcriptase (TERT), has been reported to extend life span by as much as 40% in cancer-resistant mice. On the other hand, ectopic expression of TERT promotes cancer in normal mice. However, transient induction of TERT by an astragalus-derived compound increases health span without an apparent increase in cancer incidence. Ectopic expression of TERT using adeno-associated virus serotype 9 (AAV9)-based gene therapy in adult mice increases both health span and life span without increasing cancer incidence. Available evidence suggests that increases in life span may require both elongated telomeres and the continuous presence of telomerase to stimulate the WNT/?-catenin signaling pathway. The recent observation that WNT/?-catenin signaling can stimulate TERT expression raises the possibility of a positive feedback loop between TERT and WNT/?-catenin. Such a positive feedback loop implies that safety must be carefully considered in the development of drugs that stimulate telomerase activity. PMID:22877566

Mendelsohn, Andrew R; Larrick, James W

2012-08-01

29

Neuronal expression of Mgat1 rescues the shortened life span of Drosophila Mgat11 null mutants and increases life span  

PubMed Central

The enzyme UDP-GlcNAc:?3-D-mannoside ?1,2-N-acetylglucosaminyltransferase I (GnT1, encoded by Mgat1) controls the synthesis of paucimannose N-glycans in Drosophila. We have previously reported that null mutations in Drosophila Mgat1 are viable but exhibit defects in locomotion, brain abnormalities, and a severely reduced life span. Here, we show that knockdown of Mgat1 in the central nervous system (CNS) of wild-type flies decreases locomotor activity and life span. This phenotype is similar to that observed in Drosophila Mgat11 null mutants, demonstrating that Mgat1 is required in the CNS. We also found that neuronal expression of a wild-type Mgat1 transgene rescued the shortened life span of Mgat11 null mutants and resulted in a dramatic 135% increase in mean life span relative to genetically identical controls. Neuronal expression of a wild-type Mgat1 transgene in wild-type flies resulted in a modest 9% increase in mean life span relative to genetically identical controls. In both Mgat11 null mutants and wild-type flies, neuronal expression of wild-type Mgat1 transgene resulted in a significant increase in GnT1 activity and resistance to oxidative stress. Whereas dietary restriction is not absolutely essential for the increased life span, it plays a role in the process. Interestingly, we observe a direct correlation between GnT1 activity and mean life span up to a maximum of ~136 days, showing that the ability of GnT1 activity to increase life span is limited. Altogether, these observations suggest that Mgat1-dependent N-glycosylation plays an important role in the control of Drosophila life span. PMID:20457894

Sarkar, Mohan; Iliadi, Konstantin G.; Leventis, Peter A.; Schachter, Harry; Boulianne, Gabrielle L.

2010-01-01

30

A Motivational Theory of Life-Span Development  

PubMed Central

This article had four goals. First, the authors identified a set of general challenges and questions that a life-span theory of development should address. Second, they presented a comprehensive account of their Motivational Theory of Life-Span Development. They integrated the model of optimization in primary and secondary control and the action-phase model of developmental regulation with their original life-span theory of control to present a comprehensive theory of development. Third, they reviewed the relevant empirical literature testing key propositions of the Motivational Theory of Life-Span Development. Finally, because the conceptual reach of their theory goes far beyond the current empirical base, they pointed out areas that deserve further and more focused empirical inquiry. PMID:20063963

Heckhausen, Jutta; Wrosch, Carsten; Schulz, Richard

2010-01-01

31

Reductive stress on life span extension in C. elegans  

Microsoft Academic Search

Recently, Schulz and colleagues have contributed to the ongoing controversy on the unproven role of oxidative stress in the aging process in their well-performed study 'Glucose restriction extends Caenorhabditis elegans life span by inducing mitochondrial respiration and increasing oxidative stress' (Cell Metab 2007, 6: 280293). Here, we suggest an alternative hypothesis that reductive stress can prevent calorie-restriction induced life span

Markus Ralser; Ivor J Benjamin

2008-01-01

32

Heritability of life span is largely sex limited in Drosophila.  

PubMed

Males and females differ with respect to life span and rate of aging in most animal species. Such sexual dimorphism can be associated with a complex genetic architecture, where only part of the genetic variation is shared between the sexes. However, the extent to which this is true for life span and aging is not known, because studies of life span have given contradictory results and aging has not been studied from this perspective. Here we investigate the additive genetic architecture of life span and aging in Drosophila melanogaster. We find substantial amounts of additive genetic variation for both traits, with more than three-quarters of this variation available for sex-specific evolutionary change. This result shows that the sexes have a profoundly different additive genetic basis for these traits, which has several implications. First, it translates into an, on average, three-times-higher heritability of life span within, compared to between, the sexes. Second, it implies that the sexes are relatively free to evolve with respect to these traits. And third, as life span and aging are traits that integrate over all genetic factors that contribute to mortal disease, it also implies that the genetics of heritable disease differs vastly between the sexes. PMID:24107372

Lehtovaara, Anne; Schielzeth, Holger; Flis, Ilona; Friberg, Urban

2013-11-01

33

Autobiographical memory from a life span perspective  

Microsoft Academic Search

This comparative study (i.e., three age groups, three measures) explores the distribution of retrospective and prospective autobiographical memory data across the lifespan, in particular the bump pattern of disproportionally higher recall of memories from the ages 10 to 30, as generally observed in older age groups, in conjunction with the well-known recency effect. The memory data patterns of the Life-line

JOHANNES J. F. SCHROOTS; COR VAN DIJKUM; MARIAN H. J. ASSINK

2004-01-01

34

Autobiographical memory from a life span perspective.  

PubMed

This comparative study (i.e., three age groups, three measures) explores the distribution of retrospective and prospective autobiographical memory data across the lifespan, in particular the bump pattern of disproportionally higher recall of memories from the ages 10 to 30, as generally observed in older age groups, in conjunction with the well-known recency effect. The memory data patterns of the Life-line Interview Method (LIM, the measure of this study, were compared to the published data patterns of two other memory measures (i.e., the Time Line and Life event sorting task). The results of this comparative study confirm the universality of the bump for older adults, as well as the recency effect. From the LIM data patterns it is hypothesized that both bump and recency effects play a part not only in middle-aged and older adults but also in younger people. In search for an explanation of these patterns, a theoretical outline is presented for the study of autobiographical memory as a dynamic system of both retrospective and prospective memory, subject to continuous changes across the lifespan. PMID:15248473

Schroots, Johannes J F; van Dijkum, Cor; Assink, Marian H J

2004-01-01

35

Cocoa confers life span extension in Drosophila melanogaster.  

PubMed

Cocoa is thought to be an excellent source of antioxidants. Here, we investigated the effects of cocoa supplementation on Drosophila melanogaster life span under different oxidative stress conditions. Our results illustrate that a moderate supplementation of cocoa under normoxia increases the average life span, whereas, at higher concentrations, average life span is normal. Under hyperoxia or in a Cu/Zn-superoxide dismutase-deficient background, cocoa exhibited a strong antioxidant activity, significantly increasing the average life span. Nevertheless, cocoa supplementation in a Mn-superoxide dismutase-deficient background enhanced an earlier mortality accompanied by a loss of climbing ability, indicating that cocoa may act as a pro-oxidant in mitochondria under conditions of extreme oxidative stress. Finally, we illustrate that cocoa also acts as a metal chelator in the presence of excess heavy metals, enhancing larval survival to the adult stage on copper or iron-supplemented medium. Taken together, our results document the antioxidative, pro-oxidative, and metal-chelating effects of cocoa on Drosophila melanogaster life span. PMID:19083435

Bahadorani, Sepehr; Hilliker, Arthur J

2008-06-01

36

Understanding Aggressive Behavior Across the Life Span  

PubMed Central

Aggressive behavior is the observable manifestation of aggression and is often associated with developmental transitions and a range of medical and psychiatric diagnoses across the lifespan. As healthcare professionals involved in the medical and psychosocial care of patients from birth through death, nurses frequently encounterand may serve asboth victims and perpetrators of aggressive behavior in the workplace. While the nursing literature has continually reported research on prevention and treatment approaches, less emphasis has been given to understanding the etiology, including contextual precipitants of aggressive behavior. This paper provides a brief review of the biological, social, and environmental risk factors that purportedly give rise to aggressive behavior. Further, many researchers have focused specifically on aggressive behavior in adolescence and adulthood. Less attention has been given to understanding the etiology of such behavior in young children and older adults. This paper emphasizes the unique risk factors for aggressive behavior across the developmental spectrum, including childhood, adolescence, adulthood, and late life. Appreciation of the risk factors of aggressive behavior, and, in particular, how they relate to age-specific manifestations, can aid nurses in better design and implementation of prevention and treatment programs. PMID:22471771

Liu, Jianghong; Lewis, Gary; Evans, Lois

2012-01-01

37

Decision-making heuristics and biases across the life span  

PubMed Central

We outline a contextual and motivational model of judgment and decision-making (JDM) biases across the life span. Our model focuses on abilities and skills that correspond to deliberative, experiential, and affective decision-making processes. We review research that addresses links between JDM biases and these processes as represented by individual differences in specific abilities and skills (e.g., fluid and crystallized intelligence, executive functioning, emotion regulation, personality traits). We focus on two JDM biasesthe sunk-cost fallacy (SCF) and the framing effect. We trace the developmental trajectory of each bias from preschool through middle childhood, adolescence, early adulthood, and later adulthood. We conclude that life-span developmental trajectories differ depending on the bias investigated. Existing research suggests relative stability in the framing effect across the life span and decreases in the SCF with age, including in later life. We highlight directions for future research on JDM biases across the life span, emphasizing the need for process-oriented research and research that increases our understanding of JDM biases in peoples everyday lives. PMID:22023568

Strough, JoNell; Karns, Tara E.; Schlosnagle, Leo

2013-01-01

38

Neuromodulation of Behavioral and Cognitive Development across the Life Span  

ERIC Educational Resources Information Center

Among other mechanisms, behavioral and cognitive development entail, on the one hand, contextual scaffolding and, on the other hand, neuromodulation of adaptive neurocognitive representations across the life span. Key brain networks underlying cognition, emotion, and motivation are innervated by major transmitter systems (e.g., the catecholamines

Li, Shu-Chen

2012-01-01

39

Telomere length correlates with life span of dog breeds.  

PubMed

Telomeric DNA repeats are lost as normal somatic cells replicate. When telomeres reach a critically short length, a DNA damage signal is initiated, inducing cell senescence. Some studies have indicated that telomere length correlates with mortality, suggesting that telomere length contributes to human life span; however, other studies report no correlation, and thus the issue remains controversial. Domestic dogs show parallels in telomere biology to humans, with similar telomere length, telomere attrition, and absence of somatic cell telomerase activity. Using this model, we find that peripheral blood mononuclear cell (PBMC) telomere length is a strong predictor of average life span among 15 different breeds (p < 0.0001), consistent with telomeres playing a role in life span determination. Dogs lose telomeric DNA ~10-fold faster than humans, which is similar to the ratio of average life spans between these species. Breeds with shorter mean telomere lengths show an increased probability of death from cardiovascular disease, which was previously correlated with short telomere length in humans. PMID:23260664

Fick, Laura J; Fick, Gordon H; Li, Zichen; Cao, Eric; Bao, Bo; Heffelfinger, Doug; Parker, Heidi G; Ostrander, Elaine A; Riabowol, Karl

2012-12-27

40

Developmental Intervention and Leisure Education: A Life Span Perspective  

Microsoft Academic Search

This paper offers a framework for using leisure developmentally over the life span. By considering the developmental tasks that confront individuals of a given cultural\\/historical context, educational interventions can be designed for utilizing leisure in ways that are personally and socially adaptive. Contemporary western developmental issues, such as establishing independence in adolescence, connecting with others in early adulthood and after

Douglas A. Kleiber

2001-01-01

41

Does Dietary Restriction Reduce Life Span in Male Fruit-feeding Butterflies?  

PubMed Central

Male life history and resource allocation is not frequently studied in aging and life span research. Here we verify that males of long-lived fruit-feeding butterfly species have reduced longevity on restricted diets (Beck 2007 Oecologia), in contrast to the common finding of longevity extension in dietary restriction experiments in Drosophila and some other organisms. Males of some of the most long-lived species of fruit-feeding butterflies were collected from Kibale Forest, Uganda, and kept on diets of either sugar or mashed banana. Seven out of eight species had non-significantly longer life spans on mashed banana diets. Data analysis using a time-varying Cox-model with species as covariate showed that males had reduced survival on the sugar diet during the first 35 days of captive life, but the effect was absent or reversed at more advanced ages. These results challenge the generality of dietary restriction as a way to extend life span in animals. We argue that such studies on males are promising tools for better understanding life history evolution and aging because males display a wider variety of tactics for obtaining reproductive success than females. PMID:19580860

Molleman, Freerk; Ding, Jimin; Boggs, Carol L.; Carey, James R.; Arlet, Ma?gorzata E.

2009-01-01

42

Implications of the Socioeconomic Life Cycle for a Life-Span Conception of Adult Human Development.  

ERIC Educational Resources Information Center

Behavioral development among adults is viewed from a life-span perspective. Derived from sociological literature, a life-span perspective is interpreted as a conceptualization of achievement associated with success and failure in school and in the world of work. Remarks are organized around the question of whether achievement in adults' world of

Featherman, David L.

43

HSF-1-mediated cytoskeletal integrity determines thermotolerance and life span.  

PubMed

The conserved heat shock transcription factor-1 (HSF-1) is essential to cellular stress resistance and life-span determination. The canonical function of HSF-1 is to regulate a network of genes encoding molecular chaperones that protect proteins from damage caused by extrinsic environmental stress or intrinsic age-related deterioration. In Caenorhabditis elegans, we engineered a modified HSF-1 strain that increased stress resistance and longevity without enhanced chaperone induction. This health assurance acted through the regulation of the calcium-binding protein PAT-10. Loss of pat-10 caused a collapse of the actin cytoskeleton, stress resistance, and life span. Furthermore, overexpression of pat-10 increased actin filament stability, thermotolerance, and longevity, indicating that in addition to chaperone regulation, HSF-1 has a prominent role in cytoskeletal integrity, ensuring cellular function during stress and aging. PMID:25324391

Baird, Nathan A; Douglas, Peter M; Simic, Milos S; Grant, Ana R; Moresco, James J; Wolff, Suzanne C; Yates, John R; Manning, Gerard; Dillin, Andrew

2014-10-17

44

Fundamental frequency changes of Persian speakers across the life span.  

PubMed

This study was designed to investigate changes in fundamental frequency (F0) across the life span in Persian speakers. Four hundred children and adults were asked to produce a sustained phonation of vowel /a/ and their voice samples were studied in 10 age groups. F0 was analyzed using the software Praat (Version 5.1.17.). The results revealed that (1) the mean F0 in both sexes decreases from childhood to adulthood; (2) significant F0 differences between boys and girls begin at the age of 12 years; and (3) the range of F0 changes in the life span is greater in men (178.38 Hz) than in women (113.57 Hz). These findings provide new data for Persian-speaking children, women, and men and could be beneficial for Iranian speech and language pathologists. PMID:24461477

Soltani, Majid; Ashayeri, Hasan; Modarresi, Yahya; Salavati, Mahyar; Ghomashchi, Hamed

2014-05-01

45

Essential role for autophagy in life span extension.  

PubMed

Life and health span can be prolonged by calorie limitation or by pharmacologic agents that mimic the effects of caloric restriction. Both starvation and the genetic inactivation of nutrient signaling converge on the induction of autophagy, a cytoplasmic recycling process that counteracts the age-associated accumulation of damaged organelles and proteins as it improves the metabolic fitness of cells. Here we review experimental findings indicating that inhibition of the major nutrient and growth-related signaling pathways as well as the upregulation of anti-aging pathways mediate life span extension via the induction of autophagy. Furthermore, we discuss mounting evidence suggesting that autophagy is not only necessary but, at least in some cases, also sufficient for increasing longevity. PMID:25654554

Madeo, Frank; Zimmermann, Andreas; Maiuri, Maria Chiara; Kroemer, Guido

2015-01-01

46

Synchronizing Loss with Life Over a Life Span: A Dynamic Perspective  

ERIC Educational Resources Information Center

Synchronizing loss with life is a dynamic journey. This article explores the myths, beliefs, and dynamics of loss and life. The purpose of the article is to help clinicians assist and support their clients with the difficulties of synchronizing loss with life as they progress on their life span journey.

Browning, Frank C.

2008-01-01

47

Self-determination -- A life-span perspective  

E-print Network

at identifying objectives. Finding What I Would Like to Know Planning for the Future FOCUS ON EXCEPTIONAL CHILDREN engagement in activities (Epstein, Schweinhart, & McAdoo, 1996). Both the High/Scope Curriculum (Weikert & Schwein- hart, 1993) and Reggio Emilia... abilities. However, some proponents conceptualize self-determination as a life-span approach (Abery & Stancliffe, 2003; Abery & Zajac, 1996; Sands & Wehmeyer, 1996). Viewing self-determination as a lifelong process can broaden and enhance the construct...

Palmer, Susan B.

2011-12-27

48

Life-span cognitive activity, neuropathologic burden, and cognitive aging  

PubMed Central

Objective: To test the hypothesis that cognitive activity across the life span is related to late-life cognitive decline not linked to common neuropathologic disorders. Methods: On enrollment, older participants in a longitudinal clinical-pathologic cohort study rated late-life (i.e., current) and early-life participation in cognitively stimulating activities. After a mean of 5.8 years of annual cognitive function testing, 294 individuals had died and undergone neuropathologic examination. Chronic gross infarcts, chronic microscopic infarcts, and neocortical Lewy bodies were identified, and measures of ?-amyloid burden and tau-positive tangle density in multiple brain regions were derived. Results: In a mixed-effects model adjusted for age at death, sex, education, gross and microscopic infarction, neocortical Lewy bodies, amyloid burden, and tangle density, more frequent late-life cognitive activity (estimate = 0.028, standard error [SE] = 0.008, p < 0.001) and early-life cognitive activity (estimate = 0.034, SE = 0.013, p = 0.008) were each associated with slower cognitive decline. The 2 measures together accounted for 14% of the residual variability in cognitive decline not related to neuropathologic burden. The early-lifeactivity association was attributable to cognitive activity in childhood (estimate = 0.027, SE = 0.012, p = 0.026) and middle age (estimate = 0.029, SE = 0.013, p = 0.025) but not young adulthood (estimate = ?0.020, SE = 0.014, p = 0.163). Conclusions: More frequent cognitive activity across the life span has an association with slower late-life cognitive decline that is independent of common neuropathologic conditions, consistent with the cognitive reserve hypothesis. PMID:23825173

Boyle, Patricia A.; Yu, Lei; Barnes, Lisa L.; Schneider, Julie A.; Bennett, David A.

2013-01-01

49

Rapamycin extends life- and health span because it slows aging  

PubMed Central

Making headlines, a thought-provocative paper by Neff, Ehninger and coworkers claims that rapamycin extends life span but has limited effects on aging. How is that possibly possible? And what is aging if not an increase of the probability of death with age. I discuss that the JCI paper actually shows that rapamycin slows aging and also extends lifespan regardless of its direct anti-cancer activities. Aging is, in part, MTOR-driven: a purposeless continuation of developmental growth. Rapamycin affects the same processes in young and old animals: young animals' traits and phenotypes, which continuations become hyperfunctional, harmful and lethal later in life. PMID:23934728

Blagosklonny, Mikhail V.

2013-01-01

50

Homeless aging veterans in transition: a life-span perspective.  

PubMed

The need for counseling and career/educational services for homeless veterans has captured political and economic venues for more than 25 years. Veterans are three times more likely to become homeless than the general population if veterans live in poverty or are minority veterans. This mixed methods study emphasized a life-span perspective approach for exploring factors influencing normative aging and life-quality of 39 homeless veterans in Alabama and Florida. Seven descriptive quantitative and qualitative research questions framed the investigation. Study participants completed a quantitative survey reflecting their preferences and needs with a subset of the sample (N = 12) also participating in individual qualitative interview sessions. Thirty-two service providers and stakeholders completed quantitative surveys. Empirical and qualitative data with appropriate triangulation procedures provided interpretive information relative to a life-span development perspective. Study findings provide evidence of the need for future research efforts to address strategies that focus on the health and economic challenges of veterans before they are threatened with the possibility of homelessness. Implications of the study findings provide important information associated with the premise that human development occurs throughout life with specific characteristics influencing the individual's passage. Implications for aging/homelessness research are grounded in late-life transitioning and human development intervention considerations. PMID:24286010

Thompson, Carla J; Bridier, Nancy L

2013-01-01

51

C. elegans VANG-1 modulates life span via insulin/IGF-1-like signaling.  

PubMed

The planar cell polarity (PCP) pathway is highly conserved from Drosophila to humans and a PCP-like pathway has recently been described in the nematode Caenorhabditis elegans. The developmental function of this pathway is to coordinate the orientation of cells or structures within the plane of an epithelium or to organize cell-cell intercalation required for correct morphogenesis. Here, we describe a novel role of VANG-1, the only C. elegans ortholog of the conserved PCP component Strabismus/Van Gogh. We show that two alleles of vang-1 and depletion of the protein by RNAi cause an increase of mean life span up to 40%. Consistent with the longevity phenotype vang-1 animals also show enhanced resistance to thermal- and oxidative stress and decreased lipofuscin accumulation. In addition, vang-1 mutants show defects like reduced brood size, decreased ovulation rate and prolonged reproductive span, which are also related to gerontogenes. The germline, but not the intestine or neurons, seems to be the primary site of vang-1 function. Life span extension in vang-1 mutants depends on the insulin/IGF-1-like receptor DAF-2 and DAF-16/FoxO transcription factor. RNAi against the phase II detoxification transcription factor SKN-1/Nrf2 also reduced vang-1 life span that might be explained by gradual inhibition of insulin/IGF-1-like signaling in vang-1. This is the first time that a key player of the PCP pathway is shown to be involved in the insulin/IGF-1-like signaling dependent modulation of life span in C. elegans. PMID:22359667

Honnen, Sebastian J; Bchter, Christian; Schrder, Verena; Hoffmann, Michael; Kohara, Yuji; Kampktter, Andreas; Bossinger, Olaf

2012-01-01

52

Absence of Strong Heterosis for Life Span and Other Life History Traits in Caenorhabditis Elegans  

PubMed Central

We have examined crosses between wild-type strains of Caenorhabditis elegans for heterosis effects on life span and other life history traits. Hermaphrodites of all wild strains had similar life expectancies but males of two strains had shorter life spans than hermaphrodites while males of two other strains lived longer than hermaphrodites. F(1) hermaphrodite progeny showed no heterosis while some heterosis for longer life span was detected in F(1) males. F(1) hybrids of crosses between two widely studied wild-type strains, N2 (var. Bristol) and Berg BO (var. Bergerac), were examined for rate of development, hermaphrodite fertility, and behavior; there was no heterosis for these life history traits. Both controlled variation of temperature and uncontrolled environmental variation affected the length of life of all genotypes. Significant G X E effects on life span were observed in comparisons of N2 and Berg BO hermaphrodites, or N2 hermaphrodites and males, or N2 and a Ts mutant strain (DH26). Nevertheless, within an experiment, environmental variation was minimal and life spans were quite replicable. PMID:8325483

Johnson, T. E.; Hutchinson, E. W.

1993-01-01

53

The Life Cycle and Life Span of Namibian Fairy Circles  

PubMed Central

In Namibia of southwestern Africa, the sparse grasslands that develop on deep sandy soils under rainfall between 50 and 100 mm per annum are punctuated by thousands of quasi-circular bare spots, usually surrounded by a ring of taller grass. The causes of these so-called fairy circles are unknown, although a number of hypotheses have been proposed. This paper provides a more complete description of the variation in size, density and attributes of fairy circles in a range of soil types and situations. Circles are not permanent; their vegetative and physical attributes allow them to be arranged into a life history sequence in which circles appear (birth), develop (mature) and become revegetated (die). Occasionally, they also enlarge. The appearance and disappearance of circles was confirmed from satellite images taken 4 years apart (2004, 2008). The frequency of births and deaths as a fraction of the total population of circles allowed the calculation of an approximate turnover rate, and from this, an estimate of circle lifespan. Lifespan appeared to vary with circle size, with small circles averaging about 24 years, and larger ones 4375 years. Overall lifespan averaged about 41 yr. A second, independent estimate of lifespan was made by revisiting circles 2 to 9 years after their clear status had been confirmed. This resulted in a lifespan estimate of about 60 years. Any causal explanation of fairy circles must include their birth, development and death, their mean lifespan and the variation of their features under different conditions. PMID:22761663

Tschinkel, Walter R.

2012-01-01

54

The life cycle and life span of Namibian fairy circles.  

PubMed

In Namibia of southwestern Africa, the sparse grasslands that develop on deep sandy soils under rainfall between 50 and 100 mm per annum are punctuated by thousands of quasi-circular bare spots, usually surrounded by a ring of taller grass. The causes of these so-called "fairy circles" are unknown, although a number of hypotheses have been proposed. This paper provides a more complete description of the variation in size, density and attributes of fairy circles in a range of soil types and situations. Circles are not permanent; their vegetative and physical attributes allow them to be arranged into a life history sequence in which circles appear (birth), develop (mature) and become revegetated (die). Occasionally, they also enlarge. The appearance and disappearance of circles was confirmed from satellite images taken 4 years apart (2004, 2008). The frequency of births and deaths as a fraction of the total population of circles allowed the calculation of an approximate turnover rate, and from this, an estimate of circle lifespan. Lifespan appeared to vary with circle size, with small circles averaging about 24 years, and larger ones 43-75 years. Overall lifespan averaged about 41 yr. A second, independent estimate of lifespan was made by revisiting circles 2 to 9 years after their clear status had been confirmed. This resulted in a lifespan estimate of about 60 years. Any causal explanation of fairy circles must include their birth, development and death, their mean lifespan and the variation of their features under different conditions. PMID:22761663

Tschinkel, Walter R

2012-01-01

55

Ageing effects in an iteroparous plant species with a variable life span  

PubMed Central

Background and Aims Ageing effects may be due to dysfunction leading to decreasing reproduction and survival with age. In plants, however, other (physiological) causes, associated with size for example, may also play a role. Iteroparous plants with genetically variable life spans can be helpful in unravelling these two aspects of changes associated with growing older. Methods In a long-term experiment, Beta vulgaris ssp. maritima (sea beet) plants from the same set of populations but with different ages were compared for flowering date over several years. Flowering date, root growth and seed production were measured in a synthetic population and in progenies derived from reciprocal crosses over three consecutive years and analysed with respect to the number of years yet to live. Heritabilities of these three characters and of life span were estimated. Key Results Flowering occurred on average 13 d later each year over a plant's whole lifetime. In the year before dying, plants flowered on average 33 d later and both root investment and seed production decreased significantly compared with plants that remained alive for at least 1 further year. The negative relationship (trade-off) between reproduction and root investment in early life became positive near the end of life, and the positive relationship between flowering date and root growth became negative. Conclusions Effects of ageing in the sense of a decline in reproduction and root storage combined with later flowering were particularly pronounced in the year before death. The gradual change in flowering phenology, observed over the whole lifetime, could have a physiological basis unrelated to dysfunction. PMID:19401292

Van Dijk, Henk

2009-01-01

56

Amino acid sources in the adult diet do not affect life span and fecundity in the fruit-feeding butterfly Bicyclus anynana  

PubMed Central

1. In tropical forests, the adults of many butterfly species feed on fruits rather than nectar from flowers and have long life spans. Rotting fruit and nectar differ from each other in many respects, including sources of amino acids and microbial life. If amino acids in the adult diet can be used for reproduction, this may have facilitated the evolution of extended life spans in this guild. 2. This issue was addressed by investigating effects of banana, yeast, and amino acids in the adult diet of the fruit-feeding butterfly Bicyclus anynana (Lepidoptera) on longevity and female reproductive output in two experiments. 3. Results showed that in the fruit-feeding butterfly B. anynana: (i) banana juice, but not sliced banana or added amino acids extend life span compared with a sugar solution of similar composition; (ii) compared with this sugar solution, other cohorts (banana juice-amino acid enriched) did not have significantly higher reproductive outputs; (iii) yeast does not represent a valuable source of nutrients; (iv) caloric restriction may cause decreased life span and rate of reproduction; and (v) increased rates of reproduction have a life span cost. PMID:19081752

Molleman, Freerk; Ding, Jimin; Wang, Jane-Ling; Brakefield, Paul M.; Carey, James R.; Zwaan, Bas J.

2008-01-01

57

SNEV overexpression extends the life span of human endothelial cells  

SciTech Connect

In a recent screening for genes downregulated in replicatively senescent human umbilical vein endothelial cells (HUVECs), we have isolated the novel protein SNEV. Since then SNEV has proven as a multifaceted protein playing a role in pre-mRNA splicing, DNA repair, and the ubiquitin/proteosome system. Here, we report that SNEV mRNA decreases in various cell types during replicative senescence, and that it is increased in various immortalized cell lines, as well as in breast tumors, where SNEV transcript levels also correlate with the survival of breast cancer patients. Since these mRNA profiles suggested a role of SNEV in the regulation of cell proliferation, the effect of its overexpression was tested. Thereby, a significant extension of the cellular life span was observed, which was not caused by altered telomerase activity or telomere dynamics but rather by enhanced stress resistance. When SNEV overexpressing cells were treated with bleomycin or bleomycin combined with BSO, inducing DNA damage as well as reactive oxygen species, a significantly lower fraction of apoptotic cells was found in comparison to vector control cells. These data suggest that high levels of SNEV might extend the cellular life span by increasing the resistance to stress or by improving the DNA repair capacity of the cells.

Voglauer, Regina [Institute of Applied Microbiology, Department of Biotechnology, University of Natural Resources and Applied Life Sciences Muthgasse 18, A-1190 Vienna (Austria); Chang, Martina Wei-Fen [Institute of Applied Microbiology, Department of Biotechnology, University of Natural Resources and Applied Life Sciences Muthgasse 18, A-1190 Vienna (Austria); Dampier, Brigitta [Department of Obstetrics and Gynecology, Medical University of Vienna, A-1090 Vienna (Austria); Wieser, Matthias [Institute of Applied Microbiology, Department of Biotechnology, University of Natural Resources and Applied Life Sciences Muthgasse 18, A-1190 Vienna (Austria); Baumann, Kristin [Institute of Applied Microbiology, Department of Biotechnology, University of Natural Resources and Applied Life Sciences Muthgasse 18, A-1190 Vienna (Austria); Sterovsky, Thomas [Institute of Applied Microbiology, Department of Biotechnology, University of Natural Resources and Applied Life Sciences Muthgasse 18, A-1190 Vienna (Austria); Schreiber, Martin [Department of Obstetrics and Gynecology, Medical University of Vienna, A-1090 Vienna (Austria); Katinger, Hermann [Institute of Applied Microbiology, Department of Biotechnology, University of Natural Resources and Applied Life Sciences Muthgasse 18, A-1190 Vienna (Austria); Grillari, Johannes [Institute of Applied Microbiology, Department of Biotechnology, University of Natural Resources and Applied Life Sciences Muthgasse 18, A-1190 Vienna (Austria) and BMT Research Vienna (Austria)]. E-mail: j.grillari@iam.boku.ac.at

2006-04-01

58

Exercise, brain, and cognition across the life span  

PubMed Central

This is a brief review of current evidence for the relationships between physical activity and exercise and the brain and cognition throughout the life span in non-pathological populations. We focus on the effects of both aerobic and resistance training and provide a brief overview of potential neurobiological mechanisms derived from non-human animal models. Whereas research has focused primarily on the benefits of aerobic exercise in youth and young adult populations, there is growing evidence that both aerobic and resistance training are important for maintaining cognitive and brain health in old age. Finally, in these contexts, we point out gaps in the literature and future directions that will help advance the field of exercise neuroscience, including more studies that explicitly examine the effect of exercise type and intensity on cognition, the brain, and clinically significant outcomes. There is also a need for human neuroimaging studies to adopt a more unified multi-modal framework and for greater interaction between human and animal models of exercise effects on brain and cognition across the life span. PMID:21527670

Voss, Michelle W.; Nagamatsu, Lindsay S.; Liu-Ambrose, Teresa

2011-01-01

59

Calories Do Not Explain Extension of Life Span by Dietary Restriction in Drosophila  

Microsoft Academic Search

Dietary restriction (DR) extends life span in diverse organisms, including mammals, and common mechanisms may be at work. DR is often known as calorie restriction, because it has been suggested that reduction of calories, rather than of particular nutrients in the diet, mediates extension of life span in rodents. We here demonstrate that extension of life span by DR in

William Mair; Matthew D. W Piper; Linda Partridge

2005-01-01

60

Quantitative and Molecular Genetic Analyses of Mutations Increasing Drosophila Life Span  

PubMed Central

Understanding the genetic and environmental factors that affect variation in life span and senescence is of major interest for human health and evolutionary biology. Multiple mechanisms affect longevity, many of which are conserved across species, but the genetic networks underlying each mechanism and cross-talk between networks are unknown. We report the results of a screen for mutations affecting Drosophila life span. One third of the 1,332 homozygous Pelement insertion lines assessed had quantitative effects on life span; mutations reducing life span were twice as common as mutations increasing life span. We confirmed 58 mutations with increased longevity, only one of which is in a gene previously associated with life span. The effects of the mutations increasing life span were highly sex-specific, with a trend towards opposite effects in males and females. Mutations in the same gene were associated with both increased and decreased life span, depending on the location and orientation of the Pelement insertion, and genetic background. We observed substantialand sex-specificepistasis among a sample of ten mutations with increased life span. All mutations increasing life span had at least one deleterious pleiotropic effect on stress resistance or general health, with different patterns of pleiotropy for males and females. Whole-genome transcript profiles of seven of the mutant lines and the wild type revealed 4,488 differentially expressed transcripts, 553 of which were common to four or more of the mutant lines, which include genes previously associated with life span and novel genes implicated by this study. Therefore longevity has a large mutational target size; genes affecting life span have variable allelic effects; alleles affecting life span exhibit antagonistic pleiotropy and form epistatic networks; and sex-specific mutational effects are ubiquitous. Comparison of transcript profiles of long-lived mutations and the control line reveals a transcriptional signature of increased life span. PMID:20686706

Magwire, Michael M.; Yamamoto, Akihiko; Carbone, Mary Anna; Roshina, Natalia V.; Symonenko, Alexander V.; Pasyukova, Elena G.; Morozova, Tatiana V.; Mackay, Trudy F. C.

2010-01-01

61

Prenatal Exposure to a Maternal Low Protein Diet Shortens Life Span in Rats  

Microsoft Academic Search

Background: Postweaning diet restriction is associated with prolongation of life span, reduced age-related disease and slower ageing. The effects of diet restriction imposed prior to weaning have not been so well characterised, but studies suggest an opposite effect with increased age-related diseases occurring in offspring exposed to undernutrition in prenatal life. It remains unclear whether life span is similarly adversely

Avan Aihie Sayer; Rebecca Dunn; Simon Langley-Evans; Cyrus Cooper

2001-01-01

62

Effects of calorie restriction on life span of microorganisms.  

PubMed

Calorie restriction (CR) in microorganisms such as budding and fission yeasts has a robust and well-documented impact on longevity. In order to efficiently utilize the limited energy during CR, these organisms shift from primarily fermentative metabolism to mitochondrial respiration. Respiration activates certain conserved longevity factors such as sirtuins and is associated with widespread physiological changes that contribute to increased survival. However, the importance of respiration during CR-mediated longevity has remained controversial. The emergence of several novel metabolically distinct microbial models for longevity has enabled CR to be studied from new perspectives. The majority of CR and life span studies have been conducted in the primarily fermentative Crabtree-positive yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe, but studies in primarily respiratory Crabtree-negative yeast and obligate aerobes can offer complementary insight into the more complex mammalian response to CR. Not only are microorganisms helping characterize a conserved cellular mechanism for CR-mediated longevity, but they can also directly impact mammalian metabolism as part of the natural gut flora. Here, we discuss the contributions of microorganisms to our knowledge of CR and longevity at the level of both the cell and the organism. PMID:20721547

Skinner, Craig; Lin, Su-Ju

2010-10-01

63

Programmed life span in the context of evolvability.  

PubMed

Population turnover is necessary for progressive evolution. In the context of a niche with fixed carrying capacity, aging contributes to the rate of population turnover. Theoretically, a population in which death is programmed on a fixed schedule can evolve more rapidly than one in which population turnover is left to a random death rate. Could aging evolve on this basis? Quantitative realization of this idea is problematic, since the short-term individual fitness cost is likely to eliminate any hypothetical gene for programmed death before the long-term benefit can be realized. In 2011, one of us proposed the first quantitative model based on this mechanism that robustly evolves a finite, programmed life span. That model was based on a viscous population in a rapidly changing environment. Here, we strip this model to its essence and eliminate the assumption of environmental change. We conclude that there is no obvious way in which this model is unrealistic, and that it may indeed capture an important principle of nature's workings. We suggest aging may be understood within the context of the emerging science of evolvability. PMID:25141139

Mitteldorf, Joshua; Martins, Andr C R

2014-09-01

64

Mice generated by in vitro fertilization exhibit vascular dysfunction and shortened life span.  

PubMed

Children conceived by assisted reproductive technologies (ART) display a level of vascular dysfunction similar to that seen in children of mothers with preeclamspia. The long-term consequences of ART-associated vascular disorders are unknown and difficult to investigate in healthy children. Here, we found that vasculature from mice generated by ART display endothelial dysfunction and increased stiffness, which translated into arterial hypertension in vivo. Progeny of male ART mice also exhibited vascular dysfunction, suggesting underlying epigenetic modifications. ART mice had altered methylation at the promoter of the gene encoding eNOS in the aorta, which correlated with decreased vascular eNOS expression and NO synthesis. Administration of a deacetylase inhibitor to ART mice normalized vascular gene methylation and function and resulted in progeny without vascular dysfunction. The induction of ART-associated vascular and epigenetic alterations appeared to be related to the embryo environment; these alterations were possibly facilitated by the hormonally stimulated ovulation accompanying ART. Finally, ART mice challenged with a high-fat diet had roughly a 25% shorter life span compared with control animals. This study highlights the potential of ART to induce vascular dysfunction and shorten life span and suggests that epigenetic alterations contribute to these problems. PMID:24270419

Rexhaj, Emrush; Paoloni-Giacobino, Ariane; Rimoldi, Stefano F; Fuster, Daniel G; Anderegg, Manuel; Somm, Emmanuel; Bouillet, Elisa; Allemann, Yves; Sartori, Claudio; Scherrer, Urs

2013-12-01

65

Mice generated by in vitro fertilization exhibit vascular dysfunction and shortened life span  

PubMed Central

Children conceived by assisted reproductive technologies (ART) display a level of vascular dysfunction similar to that seen in children of mothers with preeclamspia. The long-term consequences of ART-associated vascular disorders are unknown and difficult to investigate in healthy children. Here, we found that vasculature from mice generated by ART display endothelial dysfunction and increased stiffness, which translated into arterial hypertension in vivo. Progeny of male ART mice also exhibited vascular dysfunction, suggesting underlying epigenetic modifications. ART mice had altered methylation at the promoter of the gene encoding eNOS in the aorta, which correlated with decreased vascular eNOS expression and NO synthesis. Administration of a deacetylase inhibitor to ART mice normalized vascular gene methylation and function and resulted in progeny without vascular dysfunction. The induction of ART-associated vascular and epigenetic alterations appeared to be related to the embryo environment; these alterations were possibly facilitated by the hormonally stimulated ovulation accompanying ART. Finally, ART mice challenged with a high-fat diet had roughly a 25% shorter life span compared with control animals. This study highlights the potential of ART to induce vascular dysfunction and shorten life span and suggests that epigenetic alterations contribute to these problems. PMID:24270419

Rexhaj, Emrush; Paoloni-Giacobino, Ariane; Rimoldi, Stefano F.; Fuster, Daniel G.; Anderegg, Manuel; Somm, Emmanuel; Bouillet, Elisa; Allemann, Yves; Sartori, Claudio; Scherrer, Urs

2013-01-01

66

The basic reproductive ratio of life  

PubMed Central

Template-directed polymerization of nucleotides is believed to be a pathway for the replication of genetic material in the earliest cells. We assume that activated monomers are produced by prebiotic chemistry. These monomers can undergo spontaneous polymerization, a system that we call prelife. Adding template-directed polymerization changes the equilibrium structure of prelife if the rate constants meet certain criteria. In particular, if the basic reproductive ratio of sequences of a certain length exceeds one, then those sequences can attain high abundance. Furthermore, if many sequences replicate, then the longest sequences can reach high abundance even if the basic reproductive ratios of all sequences are less than one. We call this phenomenon subcritical life. Subcritical life suggests that sequences long enough to be ribozymes can become abundant even if replication is relatively inefficient. Our work on the evolution of replication has interesting parallels to infection dynamics. Life (replication) can be seen as an infection of prelife. PMID:20034501

Manapat, Michael L.; Chen, Irene A.; Nowak, Martin A.

2010-01-01

67

Increased Life Span due to Calorie Restriction in Respiratory-Deficient Yeast  

E-print Network

Increased Life Span due to Calorie Restriction in Respiratory-Deficient Yeast Matt Kaeberlein1 in respiratory- deficient cells independent of strain background, and moreover, suppresses the premature, et al. (2005) Increased life span due to calorie restriction in respiratory-deficient yeast. PLo

Dunham, Maitreya

68

Global quantification of contrasting leaf life span strategies for deciduous and  

E-print Network

RESEARCH PAPER Global quantification of contrasting leaf life span strategies for deciduous Department of Forest Resources, University of Minnesota, St Paul, MN 55108, USA ABSTRACT Aim Species with deciduous and evergreen leaf habits typically differ in leaf life span (LLS). Yet quantification

Minnesota, University of

69

Qualitative Exploration of Acculturation and Life-Span Issues of Elderly Asian Americans  

ERIC Educational Resources Information Center

Awareness of aging issues across diverse populations begins the journey toward counselors becoming culturally competent across client life spans. Understanding the life-span experiences of cultural groups is important for helping professionals. The purpose of this research was to gain insight into the qualitative experiences of Asian American

Lee, Jee Hyang; Heo, Nanseol; Lu, Junfei; Portman, Tarrell Awe Agahe

2013-01-01

70

BACKGROUND SUBTRACTION THROUGH MULTIPLE LIFE SPAN MODELING Junliang Xing, Liwei Liu, Haizhou Ai  

E-print Network

BACKGROUND SUBTRACTION THROUGH MULTIPLE LIFE SPAN MODELING Junliang Xing, Liwei Liu, Haizhou Ai.tsinghua.edu.cn, ahz@mail.tsinghua.edu.cn ABSTRACT Background subtraction plays a key role in many surveillance systems competing approaches. Index Terms-- Background subtraction, life span model- ing, visual surveillance 1

Ai, Haizhou

71

Sequential and Coordinative Processing Dynamics in Figural Transformations across the Life Span.  

ERIC Educational Resources Information Center

Investigated the proposition that two distinct factors involved in life span cognitive development are mental speed and coordination efficiency. Results show dissociable speed of processing and working memory functioning over the life span and age-related differential effects of coordinative demands. (ET)

Mayr, Ulrich; And Others

1996-01-01

72

The Rate of Source Memory Decline across the Adult Life Span  

ERIC Educational Resources Information Center

Previous studies have suggested that the ability to remember contextual information related to specific episodic experiences declines with advancing age; however, the exact moment in the adult life span when this deficit begins is still controversial. Source memory for spatial information was tested in a life span sample of 1,500 adults between

Cansino, Selene; Estrada-Manilla, Cinthya; Hernandez-Ramos, Evelia; Martinez-Galindo, Joyce Graciela; Torres-Trejo, Frine; Gomez-Fernandez, Tania; Ayala-Hernandez, Mariana; Osorio, David; Cedillo-Tinoco, Melisa; Garces-Flores, Lissete; Gomez-Melgarejo, Sandra; Beltran-Palacios, Karla; Guadalupe Garcia-Lazaro, Haydee; Garcia-Gutierrez, Fabiola; Cadena-Arenas, Yadira; Fernandez-Apan, Luisa; Bartschi, Andrea; Resendiz-Vera, Julieta; Rodriguez-Ortiz, Maria Dolores

2013-01-01

73

The Time of Our Lives: Life Span Development of Timing and Event Tracking  

E-print Network

The Time of Our Lives: Life Span Development of Timing and Event Tracking J. Devin McAuley Bowling and unpaced perceptual­motor timing tasks that included synchronize­continue tapping at a wide range of target event rates. Two life span hypotheses, derived from an entrainment theory of timing and event tracking

Liu, Taosheng

74

High Osmolarity Extends Life Span in Saccharomyces cerevisiae by a Mechanism Related to Calorie Restriction  

Microsoft Academic Search

Calorie restriction (CR) extends life span in many different organisms, including mammals. We describe here a novel pathway that extends the life span of Saccharomyces cerevisiae mother cells but does not involve a reduction in caloric content of the media, i.e., there is growth of yeast cells in the presence of a high concentration of external osmolytes. Like CR, this

Matt Kaeberlein; Alex A. Andalis; Gerald R. Fink; Leonard Guarente

2002-01-01

75

Long-lived Indy and calorie restriction interact to extend life span  

Microsoft Academic Search

Calorie restriction (CR) improves health and extends life span in a variety of species. Despite many downstream molecules and physiological systems having been identified as being regulated by CR, the mechanism by which CR extends life span remains unclear. The Drosophila gene Indy (for I'm not dead yet), involved in the transport and storage of Krebs cycle intermediates in tissues

Pei-Yu Wang; Nicola Neretti; Rachel Whitaker; Suzanne Hosier; Chengyi Chang; Daniel Lu; Blanka Rogina; Stephen L. Helfand

2009-01-01

76

An intervention resembling caloric restriction prolongs life span and retards aging in yeast  

Microsoft Academic Search

The yeast Saccharomyces cerevisiae has a finite life span that is measured by the number of daughter cells an individual produces. The 20 genes known to determine yeast life span appear to function in more than one pathway, implicating a variety of physiological processes in yeast longevity. Less attention has been focused on environmental effects on yeast aging. We have

James C. Jiang; Ewa Jaruga; Marina V. Repnevskaya; S. Michal Jazwinski

2000-01-01

77

Counting the Calories: The Role of Specific Nutrients in Extension of Life Span by Food Restriction  

Microsoft Academic Search

Reduction of food intake without malnourishment extends life span in many different organisms. The majority of work in this field has been performed in rodents where it has been shown that both restricting access to the entire diet and restricting individual dietary components can cause life-span extension. Thus, for insights into the mode of action of this intervention, it is

Matthew D. W. Piper; William Mair; Linda Partridge

2005-01-01

78

[Life span and longevity in representatives of creative professions].  

PubMed

The article presents data on mean age of death of 49 064 representatives of various creative professions: visual artists (painters, sculptors, architects, n = 8 458), musicians (composers, conductors, singers, pianists, violinists, etc. n = 7 883), writers and poets (n = 11 488), scientists (n = 21 235). The mean age of death among writers and poets was significantly (p < 0.001) less than that in visual artists, musicians and scientists whereas scientists lived longer than representatives of other categories (p < 0.001). Women lived longer than men of any studied categories (p < 0.02). It was shown that the mean age of death gradually but irregularly increased since the 1st century A. C. until the 20th century in any professional cohort. Visual artists-men in 20th century lived longer than in previous historical periods (p < 0.001). Scientists both females and males in 20th century lived longer then these in 19th century (p < 0.001). The first five places of long-livers among men belong to Nobel prize winners (78,8 yrs.), academicians (72,7 yrs.) and corresponding members of the Russian Academy of Sciences (71,7 yrs.), conductors (71,1 yrs.) and scientists (71,0 yrs.). Rock-musicians, author's song singer and poets lived less than other categories (43,6; 53,6 and 61,6 yrs. respectively). Among women leading long-livers were conductors (83,2 yrs.), harp-players (80,9 yrs.), academicians of the RAS (80,3 yrs.), clavesin-players (79,1 yrs.) and violinists (78,2 yrs.). Among women, less lived rock-musicians (37,6 yrs.), author's songs singers (51,4), horns and woodwinds instruments players (59,0 yrs.). Relative number of nonagenarians (90+) was much higher among women as compared to men. The values were as 43.75% of harp-players, 33.33% of conductors, 29.17% of architects, 20% of violinists and viola-players and 18.99% sculptors for women, and 16.67% of Nobel prize winners, 12.12% of conductors, 7.51% of academicians, 7.44% of violinists and 7.0% of scientists survived 90+ years among men. Centenarians were 8.33% of academicians and architects, 6.25% of harp-players and 4.22% of writers-poets among women, and only 0.76% of pianists, 0.45% of scientists and 0.42% of violinists were centenarians among men. Our data are in agreement with the opinion that high intellect and education directly correlate with longer life span and longevity. PMID:24640685

Anisimov, V N; Zharinov, G M

2013-01-01

79

Extension of Life-Span by Loss of CHICO, a Drosophila Insulin Receptor Substrate Protein  

Microsoft Academic Search

The Drosophila melanogaster gene chico encodes an insulin receptor substrate that functions in an insulin\\/insulin-like growth factor (IGF) signaling pathway. In the nematode Caenorhabditis elegans, insulin\\/IGF signaling regulates adult longevity. We found that mutation of chico extends fruit fly median life-span by up to 48% in homozygotes and 36% in heterozygotes. Extension of life-span was not a result of impaired

David J. Clancy; David Gems; Lawrence G. Harshman; Sean Oldham; Hugo Stocker; Ernst Hafen; Sally J. Leevers; Linda Partridge

2001-01-01

80

Regulation of Yeast Replicative Life Span by TOR and Sch9 in Response to Nutrients  

Microsoft Academic Search

Calorie restriction increases life span in many organisms, including the budding yeast Saccharomyces cerevisiae. From a large-scale analysis of 564 single-gene-deletion strains of yeast, we identified 10 gene deletions that increase replicative life span. Six of these correspond to genes encoding components of the nutrient-responsive TOR and Sch9 pathways. Calorie restriction of tor1Delta or sch9Delta cells failed to further increase

Matt Kaeberlein; R. Wilson Powers; Kristan K. Steffen; Eric A. Westman; Di Hu; Nick Dang; Emily O. Kerr; Kathryn T. Kirkland; Brian K. Kennedy

2005-01-01

81

Extension of Life-Span with Superoxide Dismutase\\/Catalase Mimetics  

Microsoft Academic Search

We tested the theory that reactive oxygen species cause aging. We augmented the natural antioxidant systems of Caenorhabditis elegans with small synthetic superoxide dismutase\\/catalase mimetics. Treatment of wild-type worms increased their mean life-span by a mean of 44 percent, and treatment of prematurely aging worms resulted in normalization of their life-span (a 67 percent increase). It appears that oxidative stress

Simon Melov; Joanne Ravenscroft; Sarwatt Malik; Matt S. Gill; David W. Walker; Peter E. Clayton; Douglas C. Wallace; Bernard Malfroy; Susan R. Doctrow; Gordon J. Lithgow

2000-01-01

82

HST2 Mediates SIR2Independent Life-Span Extension by Calorie Restriction  

Microsoft Academic Search

Calorie restriction (CR) extends the life span of numerous species, from yeast to rodents. Yeast Sir2 is a nicotinamide adenine dinucleotide (NAD+)-dependent histone deacetylase that has been proposed to mediate the effects of CR. However, this hypothesis has been challenged by the observation that CR can extend yeast life span in the absence of Sir2. Here, we show that Sir2-independent

Dudley W. Lamming; Magda Latorre-Esteves; Oliver Medvedik; Stacy N. Wong; Felicia A. Tsang; Chen Wang; Su-Ju Lin; David A. Sinclair

2005-01-01

83

Inflammatory Exposure and Historical Changes in Human Life-Spans  

Microsoft Academic Search

Most explanations of the increase in life expectancy at older ages over history emphasize the importance of medical and public health factors of a particular historical period. We propose that the reduction in lifetime exposure to infectious diseases and other sources of inflam- mationa cohort mechanism has also made an important contribution to the historical decline in old-age mortality. Analysis

Caleb E. Finch; Eileen M. Crimmins

2004-01-01

84

Conceptions of Gay Male Life-Span Development  

Microsoft Academic Search

Four of Erikson's eight psychosocial crises were used in this qualitative, exploratory study as an organizing framework. Using a semi-structured questionnaire, seven men were interviewed with the goal of understanding how they have navigated Erikson's life stages. Significant results included: an early sense of being different and a period of time between coming out to self and coming out to

David Roseborough

2004-01-01

85

Female Career Commitment (A Life-Span Perspective). Special Report.  

ERIC Educational Resources Information Center

A study that examined the personality and environmental factors affecting South African female career interest and career commitment at different life phases resulted in development of a model of vocational behavior. Selected for the study sample were 111 graduated white women employed by the Council for Scientific and Industrial Research. The

van Rooyen, J.

86

Women and Bipolar Disorder Across the Life Span  

PubMed Central

Bipolar I disorder occurs in approximately 1% of the adult population, and it affects women and men, equally. Women develop bipolar II disorder, bipolar depression, mixed mania, and a rapid-cycling course of illness more commonly than men and are at greater risk of such comorbid conditions as alcohol use problems, thyroid disease, medication-induced obesity, and migraine headaches. The treatment of bipolar disorder remains challenging. Although lithium reduces symptoms and prevents recurrence with good efficacy, a significant number of patients stop taking it. Furthermore, several anticonvulsants and antidepressants are prescribed off label for acute episodes and prophylaxis despite the lack of adequate research support. Psychotherapy may alleviate mania or depression and improve treatment compliance, yet its ability to prevent relapse remains uncertain. Changes throughout the reproductive cycle also have an impact on the onset and presentation of bipolar symptoms and the choice of treatment. This article provides an overview of common presentations and comorbidities, along with approaches to evaluation and treatment of women with bipolar disorder. PMID:15134424

Sit, Dorothy

2011-01-01

87

?-6 Polyunsaturated fatty acids extend life span through the activation of autophagy  

PubMed Central

Adaptation to nutrient scarcity depends on the activation of metabolic programs to efficiently use internal reserves of energy. Activation of these programs in abundant food regimens can extend life span. However, the common molecular and metabolic changes that promote adaptation to nutritional stress and extend life span are mostly unknown. Here we present a response to fasting, enrichment of ?-6 polyunsaturated fatty acids (PUFAs), which promotes starvation resistance and extends Caenorhabditis elegans life span. Upon fasting, C. elegans induces the expression of a lipase, which in turn leads to an enrichment of ?-6 PUFAs. Supplementing C. elegans culture media with these ?-6 PUFAs increases their resistance to starvation and extends their life span in conditions of food abundance. Supplementation of C. elegans or human epithelial cells with these ?-6 PUFAs activates autophagy, a cell recycling mechanism that promotes starvation survival and slows aging. Inactivation of C. elegans autophagy components reverses the increase in life span conferred by supplementing the C. elegans diet with these fasting-enriched ?-6 PUFAs. We propose that the salubrious effects of dietary supplementation with ?-3/6 PUFAs (fish oils) that have emerged from epidemiological studies in humans may be due to a similar activation of autophagic programs. PMID:23392608

O'Rourke, Eyleen J.; Kuballa, Petric; Xavier, Ramnik; Ruvkun, Gary

2013-01-01

88

Aspirin Delimits Platelet Life Span by Proteasomal Inhibition  

PubMed Central

Aspirin is widely used in clinical settings as an anti-inflammatory and anti-platelet drug due its inhibitory effect on cyclooxygenase activity. Although the drug has long been considered to be an effective and safe therapeutic regime against inflammatory and cardiovascular disorders, consequences of its cyclooxygenase-independent attributes on platelets, the key players in thrombogenesis, beg serious investigation. In this report we explored the effect of aspirin on platelet lifespan in murine model and its possible cytotoxicity against human platelets in vitro. Aspirin administration in mice led to significant reduction in half-life of circulating platelets, indicative of enhanced rate of platelet clearance. Aspirin-treated human platelets were found to be phagocytosed more efficiently by macrophages, associated with attenuation in platelet proteasomal activity and upregulation of conformationally active Bax, which were consistent with enhanced platelet apoptosis. Although the dosage of aspirin administered in mice was higher than the therapeutic regimen against cardiovascular events, it is comparable with the recommended anti-inflammatory prescription. Thus, above observations provide cautionary framework to critically re-evaluate prophylactic and therapeutic dosage regime of aspirin in systemic inflammatory as well as cardiovascular ailments. PMID:25126950

Nayak, Manasa K.; Dash, Ayusman; Singh, Nitesh; Dash, Debabrata

2014-01-01

89

Adolescents' ideas of normative life span development and personal future goals.  

PubMed

We investigated how 57 adolescents (23 girls and 34 boys), aged 12 to 15 years, compared their idea of normative life span development to their personal future goals. A two-stage study (questionnaire and follow-up interview) included two open-ended "life paths", measures for self-evaluation and self-other comparisons. Overlap of content categories in the life paths supported the relationship between individual goals and normative expectations about life span development, especially when it comes to the life domains of education, occupation, family, property and retirement. The respondents showed an awareness of the accumulation of social problems, reporting that crises (e.g. alcoholism) and negative events (e.g. unemployment) are more likely to occur to the average adult than in their personal future. If adolescents rated their future as better than the future of others, they also regarded that future as different from the normative life span. Self-evaluation was indirectly related with self-other comparisons. Similarity between the normative life span and personal future correlated with higher probability of problem occurrence and possibility to avoid the problems. PMID:10066330

Malmberg, L E; Norrgrd, S

1999-02-01

90

The importance of adult life-span perspective in explaining variations in political ideology.  

PubMed

As a comment on Hibbing et al.'s paper, we discuss the evolution of political and social views from more liberal to more conservative over the span of adulthood. We show that Hibbing et al.'s theoretical model creates a false prediction from this developmental perspective, as increased conservatism in the adult life-span trajectory is accompanied by the avoidance of negative bias. PMID:24970451

Sedek, Grzegorz; Kossowska, Malgorzata; Rydzewska, Klara

2014-06-01

91

Establishment of life-span extended bovine fibroblast cells carrying the characterization of primary cells.  

PubMed

Although primary bovine embryonic fibroblast (BEF) cells have previously been used as nucleus-donors for nuclear transfer (NT), it has now been proposed to use BEF cells to generate cloned cows that were genetically modified by transgenic or a knock-out system. A major limitation to gene targeting somatic cells, however, is the overall life-span of the cell. In this study, we first examined in vitro life-span of primary BEF cells. Primary BEF cells were found to be replicative senescent at passage 10th-12th, similar to primary murine embryonic fibroblast cells. To overcome this short in vitro life-span, we have optimized culture conditions to extend the life-span and determined growth characteristics of BEF cell lines. Two life-span extended BEF cell lines (designated CGFR -BO-1 and CGFR-BO-2) were shown to grow much faster than their parental primary counterparts. Both cell lines did not display any potential for abnormal growth such as foci formations in either soft-agar or confluent culture condition. In cloning experiments using these cell lines as a nuclear donor, the reconstructed karyoblasts underwent apoptosis, reprogramming and development in the blastocyst stage, at a similar frequency to those observed with parental as well as adult primary fibroblasts. Furthermore, these cell lines targeted with green fluorescence protein (GFP) were successfully transduced, selected and reprogrammed by NT to develop into a blastocyst stage with GFP expression. Our results suggested methods to extend life-span of donor cells with tremendous implications for the genetic engineering of bovine fibroblast cells. PMID:15529005

You, Seungkwon; Heo, Minhee; Moon, Jai-Hee; Kim, Sung-Chan; Kwak, Sungwook; Yoon, Du-Hak; Jin, Dongil; Hong, Ki-Chang; Foster, Douglas N; Choi, Yun-Jaie; Kim, Hyunggee

2004-10-31

92

Foraging across the life span: is there a reduction in exploration with aging?  

PubMed Central

Does foraging change across the life span, and in particular, with aging? We report data from two foraging tasks used to investigate age differences in search in external environments as well as internal search in memory. Overall, the evidence suggests that foraging behavior may undergo significant changes across the life span across internal and external search. In particular, we find evidence of a trend toward reduced exploration with increased age. We discuss these findings in light of theories that postulate a link between aging and reductions in novelty seeking and exploratory behavior. PMID:23616741

Mata, Rui; Wilke, Andreas; Czienskowski, Uwe

2013-01-01

93

Thioredoxin 1 overexpression extends mainly the earlier part of life span in mice.  

PubMed

We examined the effects of increased levels of thioredoxin 1 (Trx1) on resistance to oxidative stress and aging in transgenic mice overexpressing Trx1 [Tg(TRX1)(+/0)]. The Tg(TRX1)(+/0) mice showed significantly higher Trx1 protein levels in all the tissues examined compared with the wild-type littermates. Oxidative damage to proteins and levels of lipid peroxidation were significantly lower in the livers of Tg(TRX1)(+/0) mice compared with wild-type littermates. The survival study demonstrated that male Tg(TRX1)(+/0) mice significantly extended the earlier part of life span compared with wild-type littermates, but no significant life extension was observed in females. Neither male nor female Tg(TRX1)(+/0) mice showed changes in maximum life span. Our findings suggested that the increased levels of Trx1 in the Tg(TRX1)(+/0) mice were correlated to increased resistance to oxidative stress, which could be beneficial in the earlier part of life span but not the maximum life span in the C57BL/6 mice. PMID:21873593

Prez, Viviana I; Cortez, Lisa A; Lew, Christie M; Rodriguez, Marisela; Webb, Celeste R; Van Remmen, Holly; Chaudhuri, Asish; Qi, Wenbo; Lee, Shuko; Bokov, Alex; Fok, Wilson; Jones, Dean; Richardson, Arlan; Yodoi, Junji; Zhang, Yiqiang; Tominaga, Kaoru; Hubbard, Gene B; Ikeno, Yuji

2011-12-01

94

20S proteasome activation promotes life span extension and resistance to proteotoxicity in Caenorhabditis elegans.  

PubMed

Protein homeostasis (proteostasis) is one of the nodal points that need to be preserved to retain physiologic cellular/organismal balance. The ubiquitin-proteasome system (UPS) is responsible for the removal of both normal and damaged proteins, with the proteasome being the downstream effector. The proteasome is the major cellular protease with progressive impairment of function during aging and senescence. Despite the documented age-retarding properties of proteasome activation in various cellular models, simultaneous enhancement of the 20S core proteasome content, assembly, and function have never been reported in any multicellular organism. Consequently, the possible effects of the core proteasome modulation on organismal life span are elusive. In this study, we have achieved activation of the 20S proteasome at organismal level. We demonstrate enhancement of proteasome levels, assembly, and activity in the nematode Caenorhabditis elegans, resulting in life span extension and increased resistance to stress. We also provide evidence that the observed life span extension is dependent on the transcriptional activity of Dauer formation abnormal/Forkhead box class O (DAF-16/FOXO), skinhead-1 (SKN-1), and heat shock factor-1 (HSF-1) factors through regulation of downstream longevity genes. We further show that the reported beneficial effects are not ubiquitous but they are dependent on the genetic context. Finally, we provide evidence that proteasome core activation might be a potential strategy to minimize protein homeostasis deficiencies underlying aggregation-related diseases, such as Alzheimer's disease (AD) or Huntington's disease (HD). In summary, this is the first report demonstrating that 20S core proteasome up-regulation in terms of both content and activity is feasible in a multicellular eukaryotic organism and that in turn this modulation promotes extension of organismal health span and life span.-Chondrogianni, N., Georgila, K., Kourtis, N., Tavernarakis, N., Gonos, E. S. 20S proteasome activation promotes life span extension andresistance to proteotoxicity in Caenorhabditis elegans. PMID:25395451

Chondrogianni, Niki; Georgila, Konstantina; Kourtis, Nikos; Tavernarakis, Nektarios; Gonos, Efstathios S

2015-02-01

95

Life-Span Development of Visual Working Memory: When Is Feature Binding Difficult?  

Microsoft Academic Search

We asked whether the ability to keep in working memory the binding between a visual object and its spatial location changes with development across the life span more than memory for item information. Paired arrays of colored squares were identical or differed in the color of one square, and in the latter case, the changed color was unique on that

Nelson Cowan; Moshe Naveh-Benjamin; Angela Kilb; J. Scott Saults

2006-01-01

96

COMPARISONS OF STRUCTURE AND LIFE SPAN IN ROOTS AND LEAVES AMONG TEMPERATE TREES  

Microsoft Academic Search

Global data sets provide strong evidence of convergence for leaf structure with leaf longevity such that species having thick leaves, low specific leaf area, low mass-based nitrogen concentrations, and low photosynthetic rates typically exhibit long leaf life span. Leaf longevity and corresponding leaf structure have also been widely linked to plant potential growth rate, plant competition, and nutrient cycling. We

Jennifer M. Withington; Peter B. Reich; Jacek Oleksyn; David M. Eissenstat

2006-01-01

97

Gains and Losses in Creative Personality as Perceived by Adults across the Life Span  

ERIC Educational Resources Information Center

In this study, we used a life span model to study the subjective perception of creative personality (CP) in emerging, young, middle-aged, and older Hong Kong Chinese adults. We also asked participants to estimate the approximate age by which people develop and lose CP across adulthood. We expected an interesting interplay between internalized age

Hui, Anna N. N.; Yeung, Dannii Y.; Sue-Chan, Christina; Chan, Kara; Hui, Desmond C. K.; Cheng, Sheung-Tak

2014-01-01

98

Cancer risk among atomic bomb survivors. The RERF Life Span Study. Radiation Effects Research Foundation  

Microsoft Academic Search

This article summarizes the risk of cancer among the survivors of the atomic bombing of Hiroshima and Nagasaki. We focus primarily on the risk of death from cancer among individuals in the Life Span Study sample of the Radiation Effects Research Foundation from 1950 through 1985 based on recently revised dosimetry procedures. We report the risk of cancer other than

Y. Shimizu; W. J. Schull; H. Kato

1990-01-01

99

Adolescents' Ideas of Normative Life Span Development and Personal Future Goals.  

ERIC Educational Resources Information Center

Presents study results that supports relationship between individual goals and normative expectations about life span development, especially when it comes to domains of education, occupation, and family. Reports that respondents showed an awareness of the accumulation of social problems. Adolescents rated their future as better than the future of

Malmberg, Lar-Erik; Norrgard, Sonja

1999-01-01

100

Candidate genes affecting Drosophila life span identified by integrating microarray gene expression analysis and QTL mapping  

E-print Network

and quality of aging as a first step towards identifying genetic variants in humans. In this study, we-specificenvironmentalvariations.Sequencingthe human genome has given scant information about genetic factors in humans involved in the aging process processwithmodelorganismsshouldlaythebasicfoundationfor understanding the mechanisms affecting aging and discovering genetic variants affecting life span

Mackay, Trudy F.C.

101

Age and Sex Differences in Strategies of Coping and Defense Across the Life Span  

Microsoft Academic Search

Age and sex differences in the use of coping and defense strategies were examined in a life-span sample of 381 individuals. Participants responded to 2 self-report measures assessing mechanisms of coping and defense and measures assessing their level of cognitive complexity. Older adults used a combination of coping and defense strategies indicative of greater impulse control and the tendency to

Manfred Diehl; Nathan Coyle; Gisela Labouvie-Vief

1996-01-01

102

Body Image across the Life Span in Adult Women: The Role of Self-Objectification.  

ERIC Educational Resources Information Center

Investigated body image across life span in cross-section of women ages 20-84 years. Found that although body dissatisfaction remained stable, self-objectification, habitual body monitoring, appearance anxiety, and disordered eating all significantly decreased with age. Self- objectification mediated the relationship between age and disordered

Tiggemann, Marika; Lynch, Jessica E.

2001-01-01

103

Extending the Human Life Span: An Exploratory Study of Pro- and Anti-Longevity Attitudes  

ERIC Educational Resources Information Center

Successful efforts by biologists to substantially increase the life span of non-human animals has raised the possibility of extrapolation to humans, which in turn has given rise to bioethical argumentation, pro and con. The present study converts these arguments into pro- and anti-longevity items on a questionnaire and examines the structure and

Kogan, Nathan; Tucker, Jennifer; Porter, Matthew

2011-01-01

104

An extraordinary life span estimate for the clown anemonefish Amphiprion percula  

E-print Network

An extraordinary life span estimate for the clown anemonefish Amphiprion percula P. M. BUSTON of the clown anemonefish Amphiprion percula was studied for 1 year, in Madang Lagoon, Papua New Guinea. From reef damselfish and six times greater than the longevity expected for a fish of that size. The result

Buston, Peter

105

D-Glucosamine supplementation extends life span of nematodes and of ageing mice  

PubMed Central

D-Glucosamine (GlcN) is a freely available and commonly used dietary supplement potentially promoting cartilage health in humans, which also acts as an inhibitor of glycolysis. Here we show that GlcN, independent of the hexosamine pathway, extends Caenorhabditis elegans life span by impairing glucose metabolism that activates AMP-activated protein kinase (AMPK/AAK-2) and increases mitochondrial biogenesis. Consistent with the concept of mitohormesis, GlcN promotes increased formation of mitochondrial reactive oxygen species (ROS) culminating in increased expression of the nematodal amino acid-transporter 1 (aat-1) gene. Ameliorating mitochondrial ROS formation or impairment of aat-1-expression abolishes GlcN-mediated life span extension in an NRF2/SKN-1-dependent fashion. Unlike other calorie restriction mimetics, such as 2-deoxyglucose, GlcN extends life span of ageing C57BL/6 mice, which show an induction of mitochondrial biogenesis, lowered blood glucose levels, enhanced expression of several murine amino-acid transporters, as well as increased amino-acid catabolism. Taken together, we provide evidence that GlcN extends life span in evolutionary distinct species by mimicking a low-carbohydrate diet. PMID:24714520

Weimer, Sandra; Priebs, Josephine; Kuhlow, Doreen; Groth, Marco; Priebe, Steffen; Mansfeld, Johannes; Merry, Troy L.; Dubuis, Sbastien; Laube, Beate; Pfeiffer, Andreas F.; Schulz, Tim J.; Guthke, Reinhard; Platzer, Matthias; Zamboni, Nicola; Zarse, Kim; Ristow, Michael

2014-01-01

106

Life Span Adult Faces: Norms for Age, Familiarity, Memorability, Mood, and Picture Quality  

Microsoft Academic Search

Because faces are frequently used as stimuli in cognitive aging behavioral and neuroimaging studies, there is a need for a normed set of pictures reflecting age and ethnic diversity. Minear and Park (2004, Behavior Research Methods, Instruments, & Computers, 36, 630633) provided a large database of face pictures from average, ethnically diverse individuals across the adult life span. The current

Kristen M. Kennedy; Kelly Hope; Naftali Raz

2009-01-01

107

Effect of melatonin and pineal peptide preparation epithalamin on life span and free radical oxidation in Drosophila melanogaster.  

PubMed

It was shown previously that epithalamin delays age-related changes in reproductive and immune systems and increases the life span of mice and rats. These effects could be mediated by stimulating influences of epithalamin on synthesis and secretion of melatonin and on free radical processes. A comparative study on the effect of epithalamin and melatonin on both the life span of Drosophila melanogaster (strain HEM) and on the intensity of lipid peroxidation and activity of antioxidative enzymes in their tissues was the main aim of this work. Melatonin and epithalamin was added to the nutrition medium (100 micrograms/ml) during 2-3rd age of larvas. For survival analysis the flies were passed (five coupes per vessel) each 3-7 days. Lipid peroxidation was evaluated as the level of ketodienes (KD) and conjugated hydroperoxides (CHP) in fly tissues at the age of 11 days. Activity of Cu, Zn-superoxide dismuatse (SOD) and catalase was evaluated as well. The mean, median and maximum life span (MLS) were estimated. Mortality rate (MR) was calculated as alpha in the Gompertz equation (R = Ro (exp alpha t) and mortality rate doubling time (MRDT) as in 2/alpha. These parameters in groups of male and female flies exposed to melatonin and in male flies exposed to epithalamin were no different from the parameters for controls. However, exposure to epithalamin was followed in females by a significant increase in mean life span (by 17%, P < 0.02), of median (by 26%), of MLS by 14% and by a 2.12 times decrease of MR (P < 0.01) and MRDT (by 32%) compared with female controls. The level of CHP and KD in the tissues of male control flies was 40 and 49% less than that in females and indirectly correlates with male life span. Exposure to melatonin was followed by a decrease in the level of CHP and KD in females and the deletion of sex differences in them. Exposure to epithalamin significantly decreased the level of CHP and KD in female flies compared to controls (2.3 and 3.4 times, respectively, P < 0.001). Exposure to melatonin failed to influence the activity of catalase in males but increased it in females by 24% (P < 0.02) and failed to influence SOD activity both in males and females. Exposure to epithalamin was followed by a significant increase in activity of catalse, 20% in males and 7% in females and by an increase in SOD activity in males (41%). Thus, it was shown that exposure to epithalamin significantly increases the mean life span and MLS of female D.melanogaster and slowed down their aging rate by 2.12 times. This effect is in good agreement with the inhibiting effect of epithalamin in lipid peroxidation processes in fly tissues. PMID:9226628

Anisimov, V N; Mylnikov, S V; Oparina, T I; Khavinson, V K

1997-08-01

108

Effect of habitat preference on frond life span in three Cyathea tree ferns  

NASA Astrophysics Data System (ADS)

It has been reported that plants living in various geographical areas had different physiological forms, as factors of microenvironment have strong impacts on physiological characters. However, the physiological characters of fronds have been scarcely reported in ferns. In this study, we investigated physiological differences in response to the habitat preference in the three tree ferns in northeast Taiwan, Cyathea lepifera, C. spinulosa, and C. podophylla, prefer to open site, edge of forest, and interior forest, respectively. The canopy openness above the individuals of C. lepifera, C. spinulosa and C. podophylla were 29.2 14.10 , 7.0 3.07 and 5.0 2.24 %, respectively. Among three species, C. podophylla had the longest frond life span (13.0 4.12 months) than the two others (C. lepifera (6.8 1.29 months) and C. spinulosa (7.3 1.35 months). Our result supported the general patterns that shade intolerant species have a shorter leaf life span than shade tolerant species. The maximum net CO2 assimilation of C. lepifera, C. spinulosa and C. podophylla were 11.46 1.34, 8.27 0.69, and 6.34 0.54 ?mol CO2 m-2 s-1, respectively. As well, C. lepifera had the highest photosynthetic light saturation point (LSP), while C. podophylla had the lowest LSP among these three tree ferns. These suggested that C. lepifera could be more efficient for capturing and utilizing light resources under the larger canopy openness condition than the other two species. We also found that frond C : N ratio were positively correlated with frond life span among species. C. podophylla, with the longest frond life span, had the highest frond C : N ratio (22.17 1.95), which was followed by C. spinulosa (18.58 1.37) and C. lepifera (18.68 2.63) with shorter frond life span. The results were consistent to the theory that the fronds and leaves of shade intolerant species have high photosynthetic abilities with low C : N ratio. Key words: Canopy openness, frond life span, tree fern, Cyathea, frond C : N ratio

Chiu, Tzu Yun; Wang, Hsiang Hua; Lun Kuo, Yao; Kume, Tomonori

2013-04-01

109

Causes and consequences of variation in conifer leaf life-span  

SciTech Connect

Species with mutually supporting traits, such as high N{sub mass}, SLA, and A{sub mass}, and short leaf life-span, tend to inhabit either generally resource-rich environments or spatial and/or temporal microhabitats that are resource-rich in otherwise more limited habitats (e.g., {open_quotes}precipitation{close_quotes} ephemerals in warm deserts or spring ephemerals in the understory of temperate deciduous forests). In contrast, species with long leaf life-span often support foliage with low SLA, N{sub mass}, and A{sub mass}, and often grow in low-temperature limited, dry, and/or nutrient-poor environments. The contrast between evergreen and deciduous species, and the implications that emerge from such comparisons, can be considered a paradigm of modern ecological theory. However, based on the results of Reich et al. (1992) and Gower et al. (1993), coniferous species with foliage that persists for 9-10 years are likely to assimilate and allocate carbon and nutrients differently than other evergreen conifers that retain foliage for 2-3 years. Thus, attempts to contrast ecophysiological or ecosystem characteristics of evergreen versus deciduous life forms may be misleading, and pronounced differences among evergreen conifers may be ignored. Clearly, the deciduous-evergreen contrast, although useful in several ways, should be viewed from the broader perspective of a gradient in leaf life-span.

Reich, P.B.; Koike, T.; Gower, S.T.; Schoettle, A.W.

1995-07-01

110

Leaf life span spectrum of tropical woody seedlings: effects of light and ontogeny and consequences for survival  

PubMed Central

Background and Aims Leaf life span is widely recognized as a key life history trait associated with herbivory resistance, but rigorous comparative data are rare for seedlings. The goal of this study was to examine how light environment affects leaf life span, and how ontogenetic development during the first year may influence leaf fracture toughness, lamina density and stem density that are relevant for herbivory resistance, leaf life span and seedling survival. Methods Data from three experiments encompassing 104 neotropical woody species were combined. Leaf life span, lamina and vein fracture toughness, leaf and stem tissue density and seedling survival were quantified for the first-year seedlings at standardized ontogenetic stages in shade houses and common gardens established in gaps and shaded understorey in a moist tropical forest in Panama. Mortality of naturally recruited seedlings till 1 year later was quantified in 800 1-m2 plots from 1994 to 2011. Key Results Median leaf life span ranged widely among species, always greater in shade (ranging from 151 to >1790 d in the understorey and shade houses) than in gaps (115867 d), but with strong correlation between gaps and shade. Leaf and stem tissue density increased with seedling age, whereas leaf fracture toughness showed only a weak increase. All these traits were positively correlated with leaf life span. Leaf life span and stem density were negatively correlated with seedling mortality in shade, while gap mortality showed no correlation with these traits. Conclusions The wide spectrum of leaf life span and associated functional traits reflects variation in shade tolerance of first-year seedlings among coexisting trees, shrubs and lianas in this neotropical forest. High leaf tissue density is important in enhancing leaf toughness, a known physical defence, and leaf life span. Both seedling leaf life span and stem density should be considered as key functional traits that contribute to seedling survival in tropical forest understoreys. PMID:23532047

Kitajima, Kaoru; Cordero, Roberto A.; Wright, S. Joseph

2013-01-01

111

Demography of Genotypes: Failure of the Limited Life-Span Paradigm in Drosophila melanogaster  

NASA Astrophysics Data System (ADS)

Experimental systems that are amenable to genetic manipulation can be used to address fundamental questions about genetic and nongenetic determinants of longevity. Analysis of large cohorts of ten genotypes of Drosophila melanogaster raised under conditions that favored extended survival has revealed variation between genotypes in both the slope and location of age-specific mortality curves. More detailed examination of a single genotype showed that the mortality trajectory was best fit by a two-stage Gompertz model, with no age-specific increase in mortality rates beyond 30 days after emergence. These results are contrary to the limited life-span paradigm, which postulates well-defined, genotype-specific limits on life-span and brief periods of intense and rapidly accelerating mortality rates at the oldest ages.

Curtsinger, James W.; Fukui, Hidenori H.; Townsend, David R.; Vaupel, James W.

1992-10-01

112

Blood volume and red cell life span (M113), part C  

NASA Technical Reports Server (NTRS)

Prechamber, in-chamber, and postchamber blood samples taken from Skylab simulation crewmembers did not indicate significant shortening of the red cell life span during the mission. This does not suggest that the space simulation environment could not be associated with red cell enzyme changes. It does show that any changes in enzymes were not sufficiently great to significantly shorten red cell survival. There was no evidence of bone marrow erythropoetic suppression nor was there any evidence of increased red cell destruction.

Johnson, P. C., Jr.

1973-01-01

113

RERF Life Span Study, Adult Health Study, and F1 Cohorts (Hiroshima and Nagasaki)  

Cancer.gov

The main cohort, called the Life Span Study (LSS), consisted of about 120,000 persons of all ages and both genders in 1950 of whom more than 90,000 were exposed to atomic bomb radiation, with a wide range of exposure doses. About 45,000 LSS participants completed questionnaires in the late 1960s and periodically since then on sociodemographic, lifestyle, and other disease risk factors.

114

CD4 memory T cell levels predict life span in genetically heterogeneous mice  

Microsoft Academic Search

Aging leads to changes in the relative proportions of several functionally distinct T cell sub- sets, including increases in the proportions of mem- ory cells in the CD4 and CD8 subsets and in the proportion of T cells expressing the multiple-drug resistance pump P-glycoprotein. To see whether in- dividual differences in T cell subset levels predict life span, we measured

RICHARD A. MILLER; CLARENCE CHRISP; ANDRZEJ GALECKV

115

Extension of chronological life span in yeast by decreased TOR pathway signaling  

Microsoft Academic Search

Chronological life span (CLS) in Saccharomyces cerevisiae, defined as the time cells in a stationary phase culture remain viable, has been proposed as a model for the aging of post-mitotic tissues in mammals. We developed a high-throughput assay to determine CLS for ?4800 single-gene deletion strains of yeast, and identified long-lived strains carrying mutations in the conserved TOR pathway. TOR

R. Wilson Powers III; Matt Kaeberlein; Seth D. Caldwell; Brian K. Kennedy

2006-01-01

116

Increased aerobic metabolism is essential for the beneficial effects of caloric restriction on yeast life span  

Microsoft Academic Search

Calorie restriction is a dietary regimen capable of extending life span in a variety of multicellular organisms. A yeast model\\u000a of calorie restriction has been developed in which limiting the concentration of glucose in the growth media of Saccharomyces cerevisiae leads to enhanced replicative and chronological longevity. Since S. cerevisiae are Crabtree-positive cells that present repression of aerobic catabolism when

Graciele A. Oliveira; Erich B. Tahara; Andreas K. Gombert; Mario H. Barros; Alicia J. Kowaltowski

2008-01-01

117

Mitochondria-mediated hormetic response in life span extension of calorie-restricted Saccharomyces cerevisiae  

Microsoft Academic Search

Calorie restriction (CR) is the only proven regimen, which confers lifespan extension benefits across the various phyla right\\u000a from unicellular organisms like yeast to primates. In a bid to elucidate the mechanism of calorie-restriction-mediated life\\u000a span extension, the role of mitochondria in the process was investigated. In this study, we found that the mitochondrial content\\u000a in CR cells remains unaltered

Praveen Kumar Sharma; Vineet Agrawal; Nilanjan Roy

2011-01-01

118

Dependence of the life span of the honeybee ( Apis mellifica ) upon flight performance and energy consumption  

Microsoft Academic Search

The life span of worker-honeybees is determined by the duration of the hive-period and of the foraging period (Figs. 1,2). The duration of the forgaing period is regulated in the following way: Total flight performance of the individual bee seems to be fixed. Daily flight performance strongly affects total flight duration. High daily flight performance decreases maximal flight duration and

Angelika Neukirch

1982-01-01

119

Transient Expression of Human Telomerase Extends the Life Span of Normal Human Fibroblasts  

Microsoft Academic Search

We utilized the Cre\\/lox recombination system to transiently express the catalytic subunit of telomerase (hTERT) in normal diploid foreskin fibroblasts (BJ cells). A retroviral construct containing an hTERT cDNA, flanked by loxP-sites was introduced into near senescent BJ cells (population doubling 85). At population doubling (PD) 92, which exceeds the typical life span of these cells, we excised the gene

Susanne Steinert; Jerry W. Shay; Woodring E. Wright

2000-01-01

120

Two-carbon metabolites, polyphenols and vitamins influence yeast chronological life span in winemaking conditions  

PubMed Central

Background Viability in a non dividing state is referred to as chronological life span (CLS). Most grape juice fermentation happens when Saccharomyces cerevisiae yeast cells have stopped dividing; therefore, CLS is an important factor toward winemaking success. Results We have studied both the physical and chemical determinants influencing yeast CLS. Low pH and heat shorten the maximum wine yeast life span, while hyperosmotic shock extends it. Ethanol plays an important negative role in aging under winemaking conditions, but additional metabolites produced by fermentative metabolism, such as acetaldehyde and acetate, have also a strong impact on longevity. Grape polyphenols quercetin and resveratrol have negative impacts on CLS under winemaking conditions, an unexpected behavior for these potential anti-oxidants. We observed that quercetin inhibits alcohol and aldehyde dehydrogenase activities, and that resveratrol performs a pro-oxidant role during grape juice fermentation. Vitamins nicotinic acid and nicotinamide are precursors of NAD+, and their addition reduces mean longevity during fermentation, suggesting a metabolic unbalance negative for CLS. Moreover, vitamin mix supplementation at the end of fermentation shortens CLS and enhances cell lysis, while amino acids increase life span. Conclusions Wine S. cerevisiae strains are able to sense changes in the environmental conditions and adapt their longevity to them. Yeast death is influenced by the conditions present at the end of wine fermentation, particularly by the concentration of two-carbon metabolites produced by the fermentative metabolism, such as ethanol, acetic acid and acetaldehyde, and also by the grape juice composition, particularly its vitamin content. PMID:22873488

2012-01-01

121

Life span of B lymphocytes: the experimental basis for conflicting results  

SciTech Connect

Recent claims have challenged the view that most peripheral, mature B cells are long-lived, and propose rates of peripheral decay that are compatible with bone marrow production. This disagreement can only reflect differences in the protocols and methods used to measure peripheral lymphocyte life spans. The authors have now assessed toxic or other nonselective effects of hydroxyurea treatment on the survival and migration of peripheral, noncycling cells, as well as possible reasons for exaggerated decays of LPS-reactive B cells transferred to LPS nonresponder hosts, the two methods leading to conclusions of short life spans. They also studied general effects on cell survival introduced by either repeated (/sup 3/H)thymidine injections or the stress associated with surgery, thoracic duct cannulation in particular - methods with which the notion of long life spans had been established. The results failed to show toxic or nonselective effects of hydroxyurea treatments and artificial decays of LPS-reactive cells in adoptive hosts. In contrast, the present experiments demonstrate that both the stress associated with surgery and repeated (/sup 3/H) thymidine administration profoundly deplete a pool of short-lived B cells, consequently selecting for an apparent higher proportion of long-lived cells.

Freitas, A.A.; Rocha, B.; Coutinho, A.A.

1986-02-01

122

Neural recruitment and connectivity during emotional memory retrieval across the adult life span.  

PubMed

Although research has identified age-related changes in neural recruitment during emotional memory encoding, it is unclear whether these differences extend to retrieval. In this study, participants engaged in a recognition task during a functional magnetic resonance imaging scan. They viewed neutral titles and indicated whether each title had been presented with an image during the study phase. Neural activity and connectivity during retrieval of titles associated with positive and negative images were compared with age (treated as a continuous variable) included as a regressor of interest. Aging was associated with increased prefrontal activation for retrieval of positive and negative memories, but this pattern was more widespread for negative memories. Aging also was associated with greater negative connectivity between a left hippocampal seed region and multiple regions of prefrontal cortex, but this effect of age occurred during negative retrieval only. These findings demonstrate that age-related changes in prefrontal recruitment and connectivity during retrieval depend on memory valence. The use of a life span approach also emphasized both continuities and discontinuities in recruitment and connectivity across the adult life span, highlighting the insights to be gained from using a full life span sample. PMID:24986714

Ford, Jaclyn H; Morris, John A; Kensinger, Elizabeth A

2014-12-01

123

Submandibular salivary glands: influence on growth rate and life span in mice  

Microsoft Academic Search

Submandibular glands accumulate a variety of growth factors, especially in male mice. Surgical excision of these glands (sialoadenectomy)\\u000a results in alterations in several organs and systems including the liver, skin and reproductive system. We studied the life-long\\u000a consequences of sialoadenectomy in male mice. Animals were operated at the age of 10weeks. Thereafter, body weight and food\\u000a and water intake were

Ignasi Ramrez; Maria Soley

2011-01-01

124

Life Satisfaction, Self-Esteem, and Subjective Age in Women across the Life Span  

ERIC Educational Resources Information Center

A study of 320 women, ages 21 to 69, explored the relations among relationship status, subjective age, self-esteem, and life satisfaction. Women in married or partnered relationships had higher levels of life satisfaction than did single women. Women in their 30s and 40s had significantly lower levels of life satisfaction than did other age

Borzumato-Gainey, Christine; Kennedy, Alison; McCabe, Beth; Degges-White, Suzanne

2009-01-01

125

Life Cycle, Host Range, and Reproduction of Heterodera betulae  

PubMed Central

Heterodera betulae, a cyst-forming nematode, originally recovered from roots of river birch in Arkansas, appears to have a limited host range. Of 80 plant species in 20 families tested, only five species of Betula and Cleome spinosa supported reproduction. The minimum time for a complete life cycle was 52 days at 28 C. No reproduction occurred at 31 C or above, and development was very slow below 20 C. Successful population propagations from single larvae demonstrated that males were not necessary for reproduction. PMID:19325673

Riggs, R. D.; Hirschmann, H.; Hamblen, M. L.

1969-01-01

126

Reproductive and early life stages pathology - Histopathology workshop report  

USGS Publications Warehouse

Pathology occurring during reproduction and larval development represents an important part of the life cycle of fish, and the diseases that affect eggs and larvae often result in significant losses. However, mortality during this period is frequently ignored or poorly researched as the temptation is to replace the losses rather than investigate the causes. A histopathology workshop organised at the newly refurnished laboratory within the Danish Veterinary School was an opportunity to discuss the pathology of selected diseases associated with Reproductive and Early Life Stages Pathology. Several people also kindly provided reference slides.

Bruno, D.W.; Nowak, B.; Elliott, D.G.

2006-01-01

127

Lynx reproduction--long-lasting life cycle of corpora lutea in a feline species.  

PubMed

A review of lynxes' reproductive biology and comparison between the reproductive cycles of the domestic cat and lynxes is presented. Three of the four lynx species (the bobcat excluded) express quite similar reproductive pattern (age at sexual maturity, estrus and pregnancy length, litter size). Similarly to the domestic cat, the bobcat is polyestric and can have more than one litter per year. Domestic cats and many other felid species are known to express anovulatory, pregnant and pseudo-pregnant reproductive cycles in dependence on ovulation induction and fertilization. The formation of corpora lutea (CLs) occurs after ovulation. In pregnant animals, luteal function ends with parturition, whereas during pseudo-pregnancy a shorter life span and lower hormone secretion are observed. The life cycle of corpora lutea in Eurasian lynxes is different from the pattern described in domestic cats. Lynx CLs produce progestagens in distinctive amounts permanently for at least two years, regardless of their origin (pregnancy or pseudo-pregnancy). It is suggested that long-lasting CLs induce a negative feedback to inactivate folliculogenesis, turning a normally polyestric cycle observed in most felids into a monoestric cycle in lynxes. PMID:24856466

Jewgenow, Katarina; Painer, Johanna; Amelkina, Olga; Dehnhard, Martin; Goeritz, Frank

2014-04-01

128

From children to adults: motor performance across the life-span.  

PubMed

The life-span approach to development provides a theoretical framework to examine the general principles of life-long development. This study aims to investigate motor performance across the life span. It also aims to investigate if the correlations between motor tasks increase with aging. A cross-sectional design was used to describe the effects of aging on motor performance across age groups representing individuals from childhood to young adult to old age. Five different motor tasks were used to study changes in motor performance within 338 participants (7-79 yrs). Results showed that motor performance increases from childhood (7-9) to young adulthood (19-25) and decreases from young adulthood (19-25) to old age (66-80). These results are mirroring results from cognitive research. Correlation increased with increasing age between two fine motor tasks and two gross motor tasks. We suggest that the findings might be explained, in part, by the structural changes that have been reported to occur in the developing and aging brain and that the theory of Neural Darwinism can be used as a framework to explain why these changes occur. PMID:22719958

Leversen, Jonas S R; Haga, Monika; Sigmundsson, Hermundur

2012-01-01

129

Hippocampal volume varies with educational attainment across the life-span  

PubMed Central

Socioeconomic disparitiesand particularly differences in educational attainmentare associated with remarkable differences in cognition and behavior across the life-span. Decreased educational attainment has been linked to increased exposure to life stressors, which in turn have been associated with structural differences in the hippocampus and the amygdala. However, the degree to which educational attainment is directly associated with anatomical differences in these structures remains unclear. Recent studies in children have found socioeconomic differences in regional brain volume in the hippocampus and amygdala across childhood and adolescence. Here we expand on this work, by investigating whether disparities in hippocampal and amygdala volume persist across the life-span. In a sample of 275 individuals from the BRAINnet Foundation database ranging in age from 17 to 87, we found that socioeconomic status (SES), as operationalized by years of educational attainment, moderates the effect of age on hippocampal volume. Specifically, hippocampal volume tended to markedly decrease with age among less educated individuals, whereas age-related reductions in hippocampal volume were less pronounced among more highly educated individuals. No such effects were found for amygdala volume. Possible mechanisms by which education may buffer age-related effects on hippocampal volume are discussed. PMID:23162453

Noble, Kimberly G.; Grieve, Stuart M.; Korgaonkar, Mayuresh S.; Engelhardt, Laura E.; Griffith, Erica Y.; Williams, Leanne M.; Brickman, Adam M.

2012-01-01

130

eRapa Restores A Normal Life Span in a FAP Mouse Model  

PubMed Central

Mutation of a single copy of the adenomatous polyposis coli (APC) gene results in familial adenomatous polyposis (FAP), which confers an extremely high risk for colon cancer. ApcMin/+ mice exhibit multiple intestinal neoplasia (MIN) that causes anemia and death from bleeding by 6 months. Mechanistic target of rapamycin complex 1 (mTORC1) inhibitors were shown to improve ApcMin/+ mouse survival when administered by oral gavage or added directly to the chow, but these mice still died from neoplasia well short of a natural life span. The National Institute of Aging Intervention Testing Program showed that enterically targeted rapamycin (eRapa) extended life span for wild type genetically heterogeneous mice in part by inhibiting age-associated cancer. We hypothesized that eRapa would be effective in preventing neoplasia and extend survival of ApcMin/+ mice. We show that eRapa improved survival for ApcMin/+ mice in a dose-dependent manner. Remarkably, and in contrast to previous reports, most of the ApcMin/+ mice fed 42 ppm eRapa lived beyond the median life span reported for wild type syngeneic mice. Furthermore, chronic eRapa did not cause detrimental immune effects in mouse models of cancer, infection or autoimmunity; thus, assuaging concerns that chronic rapamycin treatment suppresses immunity. Our studies suggest that a novel formulation (enteric targeting) of a well-known and widely used drug (rapamycin) can dramatically improve its efficacy in targeted settings. eRapa or other mTORC1 inhibitors could serve as effective cancer preventatives for people with FAP without suppressing the immune system, thus reducing the dependency on surgery as standard therapy. PMID:24282255

Hasty, Paul; Livi, Carolina B.; Dodds, Sherry G.; Jones, Diane; Strong, Randy; Javors, Martin; Fischer, Kathleen E.; Sloane, Lauren; Murthy, Kruthi; Hubbard, Gene; Sun, Lishi; Hurez, Vincent; Curiel, Tyler J.; Sharp, Zelton Dave

2014-01-01

131

Photosynthetic thermotolerance of woody savanna species in China is correlated with leaf life span  

PubMed Central

Background and Aims Photosynthetic thermotolerance (PT) is important for plant survival in tropical and sub-tropical savannas. However, little is known about thermotolerance of tropical and sub-tropical wild plants and its association with leaf phenology and persistence. Longer-lived leaves of savanna plants may experience a higher risk of heat stress. Foliar Ca is related to cell integrity of leaves under stresses. In this study it is hypothesized that (1) species with leaf flushing in the hot-dry season have greater PT than those with leaf flushing in the rainy season; and (2) PT correlates positively with leaf life span, leaf mass per unit area (LMA) and foliar Ca concentration ([Ca]) across woody savanna species. Methods The temperature-dependent increase in minimum fluorescence was measured to assess PT, together with leaf dynamics, LMA and [Ca] for a total of 24 woody species differing in leaf flushing time in a valley-type savanna in south-west China. Key Results The PT of the woody savanna species with leaf flushing in the hot-dry season was greater than that of those with leaf flushing in the rainy season. Thermotolerance was positively associated with leaf life span and [Ca] for all species irrespective of the time of flushing. The associations of PT with leaf life span and [Ca] were evolutionarily correlated. Thermotolerance was, however, independent of LMA. Conclusions Chinese savanna woody species are adapted to hot-dry habitats. However, the current maximum leaf temperature during extreme heat stress (443 C) is close to the critical temperature of photosystem II (452 C); future global warming may increase the risk of heat damage to the photosynthetic apparatus of Chinese savanna species. PMID:22875810

Zhang, Jiao-Lin; Poorter, L.; Hao, Guang-You; Cao, Kun-Fang

2012-01-01

132

Reproductive and Life History Parameters of Wild Female Macaca assamensis  

PubMed Central

Information on basic reproductive parameters and life-history traits is crucial for the understanding of primate evolution, ecology, social behavior, and reproductive strategies. Here, we report 4yr of data on reproductive and life-history traits for wild female Assamese macaques (Macaca assamensis) at Phu Khieo Wildlife Sanctuary, northeastern Thailand. During 2 consecutive reproductive seasons, we investigated reproductive behavior and sexual swelling size in 16 females and collected 1832 fecal samples. Using enzyme immunoassays, we measured fecal estrogen and progesterone metabolites to assess ovarian activity and timing of ovulation and to ascertain conceptions and pregnancies. Timing of reproduction was strictly seasonal (births: AprilJuly, 86% in AprilJune, 4yr, n?=?29; conceptions: OctoberFebruary, 65% in DecemberJanuary, 2yr, n?=?17). Females showed no cyclic ovarian activity outside the mating season and conceived in their first or second cycle (mean: 1.2 cycles to conception, n?=?13). Gestation length was on average 164.2d (range: 158170, n?=?10), and females had their first infant at an age of 5yr (n?=?4). Interbirth intervals were bimodally distributed, with females giving birth on average every 13.9 or 23.2mo. Shorter interbirth intervals were linked to early parturition within the birth season. Most females displayed subcaudal sexual swellings which, however, did not reliably indicate female reproductive status or fertility. Overall, our results fall within the range of findings reported for other macaque species. These results thus add to the growing body of information available for wild macaques, facilitating comparative studies for a better understanding of interspecific differences in social and reproductive patterns. PMID:20651906

Schlke, Oliver; Heistermann, Michael; Ostner, Julia

2010-01-01

133

Linking Peroxiredoxin and Vacuolar-ATPase Functions in Calorie Restriction-Mediated Life Span Extension  

PubMed Central

Calorie restriction (CR) is an intervention extending the life spans of many organisms. The mechanisms underlying CR-dependent retardation of aging are still poorly understood. Despite mechanisms involving conserved nutrient signaling pathways proposed, few target processes that can account for CR-mediated longevity have so far been identified. Recently, both peroxiredoxins and vacuolar-ATPases were reported to control CR-mediated retardation of aging downstream of conserved nutrient signaling pathways. In this review, we focus on peroxiredoxin-mediated stress-defence and vacuolar-ATPase regulated acidification and pinpoint common denominators between the two mechanisms proposed for how CR extends life span. Both the activities of peroxiredoxins and vacuolar-ATPases are stimulated upon CR through reduced activities in conserved nutrient signaling pathways and both seem to stimulate cellular resistance to peroxide-stress. However, whereas vacuolar-ATPases have recently been suggested to control both Ras-cAMP-PKA- and TORC1-mediated nutrient signaling, neither the physiological benefits of a proposed role for peroxiredoxins in H2O2-signaling nor downstream targets regulated are known. Both peroxiredoxins and vacuolar-ATPases do, however, impinge on mitochondrial iron-metabolism and further characterization of their impact on iron homeostasis and peroxide-resistance might therefore increase our understanding of the beneficial effects of CR on aging and age-related diseases. PMID:24639875

2014-01-01

134

Caenorhabditis elegans RNA-processing Protein TDP-1 Regulates Protein Homeostasis and Life Span*?  

PubMed Central

Transactive response DNA-binding protein (TARDBP/TDP-43), a heterogeneous nuclear ribonucleoprotein (hnRNP) with diverse activities, is a common denominator in several neurodegenerative disorders, including amyotrophic lateral sclerosis and frontotemporal lobar degeneration. Orthologs of TDP-43 exist in animals ranging from mammals to invertebrates. Here, we systematically studied mutant Caenorhabditis elegans lacking the nematode TDP-43 ortholog, TDP-1. Heterologous expression of human TDP-43 rescued the defects in C. elegans lacking TDP-1, suggesting their functions are conserved. Although the tdp-1 mutants exhibited deficits in fertility, growth, and locomotion, loss of tdp-1 attenuated defects in several C. elegans models of proteotoxicity. Loss of tdp-1 suppressed defects in transgenic C. elegans expressing TDP-43 or CuZn superoxide dismutase, both of which are associated with proteotoxicity in neurodegenerative diseases. Loss of tdp-1 also reduced defects in mutant animals lacking the heat shock factor HSF-1. Transcriptional profiling demonstrated that the loss of TDP-1 altered expression of genes functioning in RNA processing and protein folding. Furthermore, the absence of tdp-1 extended the life span in C. elegans. The life span extension required a FOXO transcriptional factor DAF-16 but not HSF-1. These results suggest that the C. elegans TDP-1 has a role in the regulation of protein homeostasis and aging. PMID:22232551

Zhang, Tao; Hwang, Ho-Yon; Hao, Haiping; Talbot, Conover; Wang, Jiou

2012-01-01

135

Mitochondrial membrane peroxidizability index is inversely related to maximum life span in mammals.  

PubMed

The oxidative stress theory of aging predicts a low degree of fatty acid unsaturation in tissues of longevous animals, because membrane lipids increase their sensitivity to oxidative damage as a function of their unsaturation. Accordingly, the fatty acids analyses of liver mitochondria from eight mammals, ranging in maximum life span from 3.5 to 46 years, show that the total number of double bonds and the peroxidizability index are negatively correlated with maximum life span (r = -0. 88, P < 0.003; r = -0.87, P < 0.004, respectively). This is not due to a low content of unsaturated fatty acids in longevous animals, but mainly to a redistribution between kinds of the polyunsaturated n-3 fatty acids series, shifting from the highly unsaturated docosahexaenoic acid (r = -0.89, P < 0.003) to the less unsaturated linolenic acid (r = 0.97, P < 0.0001). This redistribution pattern strongly suggests the presence of a constitutively low delta6-desaturase activity in longevous animals (r = -0.96, P < 0.0001). Thus, it may be proposed that, during evolution, a low degree of fatty acid unsaturation in liver mitochondria may have been selected in longevous mammals in order to protect the tissues against oxidative damage, while maintaining an appropriate environment for membrane function. PMID:9788245

Pamplona, R; Portero-Otn, M; Riba, D; Ruiz, C; Prat, J; Bellmunt, M J; Barja, G

1998-10-01

136

The mitochondrial plasmid pAL2-1 reduces calorie restriction mediated life span extension in the filamentous fungus Podospora anserina  

Microsoft Academic Search

Calorie restriction is the only life span extending regimen known that applies to all aging organisms. Although most fungi do not appear to senesce, all natural isolates of the modular filamentous fungus Podospora anserina have a limited life span. In this paper, we show that calorie restriction extends life span also in Podospora anserina. The response to glucose limitation varies

Marc F. P. M Maas; Hugo J. de Boer; Alfons J. M Debets; Rolf F Hoekstra

2004-01-01

137

Spermatozoid life-span of two brown seaweeds, Saccharina japonica and Undaria pinnatifida, as measured by fertilization efficiency  

NASA Astrophysics Data System (ADS)

During sexual reproduction of seaweeds, spermatozoid (sperm) discharge is triggered by chemical messengers (pheromones) released by the female gametes. The chemotactic ability of the sperm ensures fertilization success. Using unialgal male and female gametophyte material under designated standard gametogenesis testing (SGT) conditions, the potential life-span of the sperm of two seaweeds, Saccharina japonica and Undaria pinnatifida, was assessed by their ability to fertilize eggs. Results show that within 20-30 min after being discharged, sperm of both species could complete fertilization without an apparent decline in fertilization rate. Although fertilization rate 60-120 min after sperm discharge dropped significantly in both species, some sperm were viable enough to fertilize the eggs. In S. japonica, at 12C, some sperm were able to fertilize eggs up to 12 h after discharge. In both species, egg discharge rates (EDR) in the male and female mixed positive controls were significantly higher than those of all the sperm-testing groups. Doubling the seeded male gametophytes of S. japonica in the SGT tests significantly increased the EDR, further confirming the effect of the presence of the male on the female in terms of facilitating egg discharge from oogonia.

Li, Jing; Pang, Shaojun; Liu, Feng; Shan, Tifeng; Gao, Suqin

2013-07-01

138

Distinct Biological Epochs in the Reproductive Life of Female Drosophila melanogaster  

PubMed Central

Mating alters the physiology and behavior of female Drosophila melanogaster resulting in a surge of egg laying, a decrease in receptivity to other males, and a decrease in life span. Here, we show striking differences in patterns of Drosophila egg laying and mortality rate dependent upon mating history. Our data reveal previously unreported epochs in the reproductive life of females: optimal, vulnerable and declining-terminal. During the optimal period, mating induces females to respond with a surge in egg laying and has a reversible effect on mortality rate. In contrast, during the vulnerable period, mating does not induce females to respond with a surge in egg laying and causes an irreversible increase in mortality rate. The terminal period was always observed several days before death, irrespective of the chronological age, and is marked by sharp reductions in egg laying. The presence of these distinctive biological epochs may reflect increased female sensitivity to mating due to age-related decline. PMID:17681363

Rogina, Blanka; Wolverton, Tom; Bross, Tyson G.; Chen, Kun; Mller, Hans-Georg; Carey, James R.

2008-01-01

139

Life-history theory, fertility and reproductive success in humans.  

PubMed Central

According to life-history theory, any organism that maximizes fitness will face a trade-off between female fertility and offspring survivorship. This trade-off has been demonstrated in a variety of species, but explicit tests in humans have found a positive linear relationship between fitness and fertility. The failure to demonstrate a maximum beyond which additional births cease to enhance fitness is potentially at odds with the view that human fertility behaviour is currently adaptive. Here we report, to our knowledge, the first clear evidence for the predicted nonlinear relationship between female fertility and reproductive success in a human population, the Dogon of Mali, West Africa. The predicted maximum reproductive success of 4.1+/-0.3 surviving offspring was attained at a fertility of 10.5 births. Eighty-three per cent of the women achieved a lifetime fertility level (7-13 births) for which the predicted mean reproductive success was within the confidence limits (3.4 to 4.8) for reproductive success at the optimal fertility level. Child mortality, rather than fertility, was the primary determinant of fitness. Since the Dogon people are farmers, our results do not support the assumptions that: (i) contemporary foragers behave more adaptively than agriculturalists, and (ii) that adaptive fertility behaviour ceased with the Neolithic revolution some 9000 years ago. We also present a new method that avoids common biases in measures of reproductive success. PMID:11916470

Strassmann, Beverly I; Gillespie, Brenda

2002-01-01

140

Biological impact of auditory expertise across the life span: musicians as a model of auditory learning.  

PubMed

Experience-dependent characteristics of auditory function, especially with regard to speech-evoked auditory neurophysiology, have garnered increasing attention in recent years. This interest stems from both pragmatic and theoretical concerns as it bears implications for the prevention and remediation of language-based learning impairment in addition to providing insight into mechanisms engendering experience-dependent changes in human sensory function. Musicians provide an attractive model for studying the experience-dependency of auditory processing in humans due to their distinctive neural enhancements compared to nonmusicians. We have only recently begun to address whether these enhancements are observable early in life, during the initial years of music training when the auditory system is under rapid development, as well as later in life, after the onset of the aging process. Here we review neural enhancements in musically trained individuals across the life span in the context of cellular mechanisms that underlie learning, identified in animal models. Musicians' subcortical physiologic enhancements are interpreted according to a cognitive framework for auditory learning, providing a model in which to study mechanisms of experience-dependent changes in human auditory function. PMID:23988583

Strait, Dana L; Kraus, Nina

2014-02-01

141

Sleep tight: exploring the relationship between sleep and attachment style across the life span.  

PubMed

Based on early life experiences in which developmental, genetic, and environmental components interact, humans learn to trust themselves and others and connect emotionally in consistent ways that are broadly defined as "attachment styles." These relatively stable patterns of interpersonal interaction are associated with either vulnerability to various health risks or resilience. Similarly, the mechanisms involved in sleep regulation undergo developmental changes that overlap temporally with attachment formation and remain sensitive to a series of biological, environmental and psychological influences. Interestingly, while sleep has been conceptualized as a fundamental attachment behavior given its dyadic context, few studies have explored its relationship with attachment style in various ages. We present the first systematic review of the published literature examining the relationship between attachment style and sleep in humans across the life span. While levels of evidence and methods of assessment vary significantly, the results suggest a possible life-long relationship between individual attachment style and sleep. These findings are particularly useful in understanding relatively ingrained psychological mechanisms that can affect and be affected by sleep. Clinical and research implications are discussed. PMID:24721278

Adams, G Camelia; Stoops, Melissa A; Skomro, Robert P

2014-12-01

142

Biological impact of auditory expertise across the life span: musicians as a model of auditory learning  

PubMed Central

Experience-dependent characteristics of auditory function, especially with regard to speech-evoked auditory neurophysiology, have garnered increasing attention in recent years. This interest stems from both pragmatic and theoretical concerns as it bears implications for the prevention and remediation of language-based learning impairment in addition to providing insight into mechanisms engendering experience-dependent changes in human sensory function. Musicians provide an attractive model for studying the experience-dependency of auditory processing in humans due to their distinctive neural enhancements compared to nonmusicians. We have only recently begun to address whether these enhancements are observable early in life, during the initial years of music training when the auditory system is under rapid development, as well as later in life, after the onset of the aging process. Here we review neural enhancements in musically trained individuals across the life span in the context of cellular mechanisms that underlie learning, identified in animal models. Musicians subcortical physiologic enhancements are interpreted according to a cognitive framework for auditory learning, providing a model by which to study mechanisms of experience-dependent changes in auditory function in humans. PMID:23988583

Strait, Dana L.; Kraus, Nina

2013-01-01

143

Drosophila melanogaster p53 has developmental stage-specific and sex-specific effects on adult life span indicative of sexual antagonistic pleiotropy  

PubMed Central

Truncated and mutant forms ofp53 affect life span in Drosophila, nematodes and mice, however the role of wild-type p53 in aging remains unclear. Here conditional over-expression of both wild-type and mutant p53 transgenes indicated that, in adult flies, p53 limits life span in females but favors life span in males. In contrast, during larval development, moderate over-expression of p53 produced both male and female adults with increased life span. Mutations of the endogenous p53 gene also had sex-specific effects on life span under control and stress conditions: null mutation of p53 increased life span in females, and had smaller, more variable effects in males. These developmental stage-specific and sex-specific effects of p53 on adult life span are consistent with a sexual antagonistic pleiotropy model. PMID:20157574

Waskar, Morris; Landis, Gary N.; Shen, Jie; Curtis, Christina; Tozer, Kevin; Abdueva, Diana; Skvortsov, Dmitriy; Tavar, Simon; Tower, John

2009-01-01

144

A-bomb data: detection of bias in the Life Span Study cohort.  

PubMed

By drawing a distinction between A-bomb survivors with and without bomb-related injuries, it was possible to see that instead of the Life Span Study (LSS) cohort being a normal, homogenous population, there were significant differences between survivors with and without multiple injuries, and that these differences occurred largely among survivors who were under 10 or over 50 years of age when exposed. There also was a concentration of A-bomb-related injuries among survivors who eventually developed leukemia. So it is possible that deaths before 1950 had left the LSS cohort permanently biased in favor of persons who had high levels of resistance to all (early and late) effects of radiation. It is also possible that the high proportion of leukemia cases among the deaths of A-bomb survivors from 1950 to 1970 were because the radiation caused an initial leukocytosis followed by loss of immunologic competence. PMID:9467075

Stewart, A

1997-12-01

145

Cultural variation in verbal versus spatial neuropsychological function across the life span.  

PubMed

Established culture-invariant measures are needed for cross-cultural assessment of verbal and visuospatial speed of processing and working memory across the life span. In this study, 32 younger and 32 older adults from China and from the United States were administered numerically based and spatially based measures of speed of processing and working memory. Chinese superiority on the numerically based tasks was found for younger adults. Age and increasing task demands diminished this cultural effect, as predicted by the framework proposed by D. C. Park, R. Nisbett, and T. Hedden (1999). However, the visuospatial measures of both working memory and speed of processing did not differ cross-culturally for either age group. The authors concluded that these visuospatial measures provide culture-invariant estimates of cognitive processes in East Asian and Western cultures, but that numerically based tasks show evidence of cultural and linguistic biases in performance levels. PMID:11853358

Hedden, Trey; Park, Denise C; Nisbett, Richard; Ji, Li-Jun; Jing, Qicheng; Jiao, Shulan

2002-01-01

146

Invited commentary: missing doses in the life span study of Japanese atomic bomb survivors.  

PubMed

The Life Span Study is a long-term epidemiologic cohort study of survivors of the atomic bombs dropped on Hiroshima and Nagasaki, Japan. In this issue of the Journal, Richardson et al. (Am J Epidemiol. 2013;177(6):562-568) suggest that those who died in the earliest years of follow-up were more likely to have a missing dose of radiation exposure assigned, leading to a bias in the radiation risk estimates. We show that nearly all members of the cohort had shielding information recorded before the beginning of follow-up and that much of the alleged bias that Richardson et al. describe simply reflects the geographic distribution of shielding conditions for which reliable dosimetry was impossible. PMID:23429724

Ozasa, K; Grant, E J; Cullings, H M; Shore, R E

2013-03-15

147

Niacin-bound chromium increases life span in Zucker Fatty Rats.  

PubMed

Avoiding insulin resistance (IR) associated with aging might lengthen life span based on previous studies using caloric-restricted animals. We assessed whether consuming niacin-bound chromium (NBC) alone or in a formula containing other so-called "insulin sensitizers" would overcome various manifestations of aging and extend life span in Zucker Fatty Rats (ZFR). We compared many metabolic parameters of ZFR fed NBC alone (n=12) or NBC in a unique formula (n=10) to a control group (n=10). In addition to NBC, the formula contained Allium sativum, Momordica charantia, Trigonella foenum-graecum and Gymnema sylvestre. The formula group received roughly 1/2 as much NBC daily as the NBC group. At week 44, all rats still lived, and no abnormalities in blood count (CBC), renal, or liver functions were found. In the two treatment groups compared to control, circulating glucose levels were significantly lower, with a trend toward lower HbA1C. Relatively elevated cholesterol and triglyceride concentrations occurred in the formula group. Compared to control, the NBC group had increased average lifespan (21.8%), median lifespan (14.1%), 30th percentile survival (19.6%), and maximum lifespan (22%). Despite similar beneficial effects on the glucose and blood pressure systems, a difference in aging was also found when the NBC group was compared to the formula group. When all rats in the other two groups had died, four in the NBC group continued to live at least a month longer. We attribute lack of a similar aging effect in the formula group to either lower dosing of NBC and/or that various ingredients in the formula counteracted the antiaging effect(s) of NBC. PMID:21930012

Preuss, Harry G; Echard, Bobby; Clouatre, Dallas; Bagchi, Debasis; Perricone, Nicholas V

2011-10-01

148

Virtual navigation strategies from childhood to senescence: evidence for changes across the life span  

PubMed Central

This study sought to investigate navigational strategies across the life span, by testing 8-years old children to 80-years old healthy older adults on the 4 on 8 virtual maze (4/8VM). The 4/8VM was previously developed to assess spontaneous navigational strategies, i.e., hippocampal-dependent spatial strategies (navigation by memorizing relationships between landmarks) versus caudate nucleus-dependent response strategies (memorizing a series of left and right turns from a given starting position). With the 4/8VM, we previously demonstrated greater fMRI activity and gray matter in the hippocampus of spatial learners relative to response learners. A sample of 599 healthy participants was tested in the current study. Results showed that 84.4% of children, 46.3% of young adults, and 39.3% of older adults spontaneously used spatial strategies (p < 0.0001). Our results suggest that while children predominantly use spatial strategies, the proportion of participants using spatial strategies decreases across the life span, in favor of response strategies. Factors promoting response strategies include repetition, reward and stress. Since response strategies can result from successful repetition of a behavioral pattern, we propose that the increase in response strategies is a biological adaptive mechanism that allows for the automatization of behavior such as walking in order to free up hippocampal-dependent resources. However, the down-side of this shift from spatial to response strategies occurs if people stop building novel relationships, which occurs with repetition and routine, and thereby stop stimulating their hippocampus. Reduced fMRI activity and gray matter in the hippocampus were shown to correlate with cognitive deficits in normal aging. Therefore, these results have important implications regarding factors involved in healthy and successful aging. PMID:23162463

Bohbot, Veronique D.; McKenzie, Sam; Konishi, Kyoko; Fouquet, Celine; Kurdi, Vanessa; Schachar, Russel; Boivin, Michel; Robaey, Philippe

2012-01-01

149

Expressions of ecological identity across the life span of eight environmental exemplars  

NASA Astrophysics Data System (ADS)

While there is a substantial body of literature looking at various aspects of ecological identity and factors that influence it, there has been less work done on how an individual's ecological identity changes with time. Much of that work is limited to short segments of the life span (e.g. the impact of wilderness experiences). This dissertation attempts to address this perceived gap by investigating how the ecological identity of eight environmental exemplars changed during the course of his or her life. What has emerged from this qualitative grounded theory investigation of the lives and works of Charles Darwin, John Muir, Aldo Leopold, Marjory Stoneman Douglas, Hazel Wolf, Rachel Carson, James Lovelock and E.O. Wilson are five sequential expressions of ecological identity. These 'stages' serve as a framework to explain ecological identity as a developmental process, both fluid and continuous, rather than at) end product. The development of an ecological identity is traced, through the development of five cognitive foundations and their alignment with five emotional foundations that reflect a progression from a sensory interaction and a kinship bond with nature into a deep understanding of the interconnectedness of all aspects of the planet. The findings reveal the evolution of an ecological identity and suggest the importance of looking beyond content knowledge in the nurturing of ecological attitudes, values, and lifestyles.

Seydel, Jennifer

150

The activity-dependent histone variant H2BE modulates the life span of olfactory neurons  

PubMed Central

We have identified a replication-independent histone variant, Hist2h2be (referred to herein as H2be), which is expressed exclusively by olfactory chemosensory neurons. Levels of H2BE are heterogeneous among olfactory neurons, but stereotyped according to the identity of the co-expressed olfactory receptor (OR). Gain- and loss-of-function experiments demonstrate that changes in H2be expression affect olfactory function and OR representation in the adult olfactory epithelium. We show that H2BE expression is reduced by sensory activity and that it promotes neuronal cell death, such that inactive olfactory neurons display higher levels of the variant and shorter life spans. Post-translational modifications (PTMs) of H2BE differ from those of the canonical H2B, consistent with a role for H2BE in altering transcription. We propose a physiological function for H2be in modulating olfactory neuron population dynamics to adapt the OR repertoire to the environment. DOI: http://dx.doi.org/10.7554/eLife.00070.001 PMID:23240083

Santoro, Stephen W; Dulac, Catherine

2012-01-01

151

Production and life span of cutaneous mast cells in young rats.  

PubMed Central

Tritiated thymidine was injected into young rats (age 7 days) in such a way as to be incorporated into the nuclei of all cells that were synthesizing DNA during a period of 22 hours. Specimens of the skin of the back and the pinna of the ear were taken at intervals from one to 112 days after injection of the [3H]thymidine. The mast cells were stained with Alcian blue, and autoradiographs were prepared. The nuclei were counterstained with alum-brazilin. Making due allowance for growth of the animals, and for shrinkage due to histological preparation, the total numbers of mast cells in the dorsal skin and in the pinna were determined. The numbers of mast cells containing [3H]thymidine were calculated from the proportions of those cells found to have radioactive nuclie. Using these data, the rates of appearance of labelled mast cells, and of decline in their numbers with time were determined for both regions of skin. No mitotic figures were seen in any mast cells. It is concluded that mast cells arise by the division of agranular precursor cells of unknown identity. The characteristic cytoplasmic granules appear to be produced by the daughter cells during the 24-48 hours following premitotic replication of DNA in the precursors. The differentiated cells have half-lives of 4-9 days in the skin of the back and 7-20 days in the external ear. All the labelled mast cells had disappeared after 28 days in the back and after 84 days in the ear. Comparison of these findings with the results of other investigators suggests that the mast cells produced early in life have much shorter life spans than do most of the mast cells present in adult rats, The longer life span found in the pinna may account for the greater density of the cells there than in the back. This regional difference may reflect the greater need for mast cells in a region which is more susceptible to adverse environmental influences. PMID:438085

Kiernan, J A

1979-01-01

152

Improvement/Maintenance and Reorientation as Central Features of Coping with Major Life Change and Loss: Contributions of Three Life-Span Theories  

ERIC Educational Resources Information Center

This article focuses on the common and unique contributions of three major life-span theories in addressing improvement/maintenance and reorientation, which represent central processes of coping with major life change and loss. For this purpose, we review and compare the dual-process model of assimilative and accommodative coping, the model of

Boerner, Kathrin; Jopp, Daniela

2007-01-01

153

Cognitive control and language across the life span: does labeling improve reactive control?  

PubMed

How does cognitive control change with age, and what are the processes underlying these changes? This question has been extensively studied using versions of the task-switching paradigm, which allow participants to actively prepare for the upcoming task (Kray, Eber, & Karbach, 2008). Little is known, however, about age-related changes in this ability across the life span when there is no opportunity to anticipate task goals. We examined the effect of 2 kinds of verbal self-instruction-labeling either the task goal or the relevant feature of the stimulus-on 2 components of cognitive control, goal setting and switching, in children, young adults, and older adults. All participants performed single-task blocks and mixed-task blocks (involving unpredictable switching between 2 tasks) in silent and labeling conditions. Participants categorized bidimensional stimuli either by picture or by color, depending on their spatial position in a 2-cell vertical grid. Response times revealed an inverted U shape in performance with age. These age differences were more pronounced for goal setting than for switching, thus generalizing results obtained in situations taping proactive control to this new context forcing reactive control. Further, differential age-related effects of verbalization were also obtained. Verbalizations were detrimental for young adults, beneficial for older adults, and had mixed effects in children. These differences are interpreted in terms of qualitative developmental changes in reactive goal-setting strategies. PMID:24491213

Lucenet, Joanna; Blaye, Agns; Chevalier, Nicolas; Kray, Jutta

2014-05-01

154

Liver-Specific ?-Glutamyl Carboxylase-Deficient Mice Display Bleeding Diathesis and Short Life Span  

PubMed Central

Vitamin K is a fat-soluble vitamin that plays important roles in blood coagulation and bone metabolism. One of its functions is as a co-factor for ?-glutamyl carboxylase (Ggcx). Conventional knockout of Ggcx causes death shortly after birth in homozygous mice. We created Ggcx-floxed mice by inserting loxP sequences at the sites flanking exon 6 of Ggcx. By mating these mice with albumin-Cre mice, we generated Ggcx-deficient mice specifically in hepatocytes (Ggcx?liver/?liver mice). In contrast to conventional Ggcx knockout mice, Ggcx?liver/?liver mice had very low activity of Ggcx in the liver and survived several weeks after birth. Furthermore, compared with heterozygous mice (Ggcx+/?liver), Ggcx?liver/?liver mice had shorter life spans. Ggcx?liver/?liver mice displayed bleeding diathesis, which was accompanied by decreased activity of coagulation factors II and IX. Ggcx-floxed mice can prove useful in examining Ggcx functions in vivo. PMID:24520408

Azuma, Kotaro; Tsukui, Tohru; Ikeda, Kazuhiro; Shiba, Sachiko; Nakagawa, Kimie; Okano, Toshio; Urano, Tomohiko; Horie-Inoue, Kuniko; Ouchi, Yasuyoshi; Ikawa, Masahito; Inoue, Satoshi

2014-01-01

155

Bone marrow transplantation prolongs life span and ameliorates neurologic manifestations in Sandhoff disease mice.  

PubMed Central

The GM2 gangliosidoses are a group of severe, neurodegenerative conditions that include Tay-Sachs disease, Sandhoff disease, and the GM2 activator deficiency. Bone marrow transplantation (BMT) was examined as a potential treatment for these disorders using a Sandhoff disease mouse model. BMT extended the life span of these mice from approximately 4.5 mo to up to 8 mo and slowed their neurologic deterioration. BMT also corrected biochemical deficiencies in somatic tissues as indicated by decreased excretion of urinary oligosaccharides, and lower glycolipid storage and increased levels of beta-hexosaminidase activity in visceral organs. Even with neurologic improvement, neither clear reduction of brain glycolipid storage nor improvement in neuronal pathology could be detected, suggesting a complex pathogenic mechanism. Histological analysis revealed beta-hexosaminidase-positive cells in the central nervous system and visceral organs with a concomitant reduction of colloidal iron-positive macrophages. These results may be important for the design of treatment approaches for the GM2 gangliosidoses. PMID:9576752

Norflus, F; Tifft, C J; McDonald, M P; Goldstein, G; Crawley, J N; Hoffmann, A; Sandhoff, K; Suzuki, K; Proia, R L

1998-01-01

156

Dietary intake of Curcuma longa and Emblica officinalis increases life span in Drosophila melanogaster.  

PubMed

Intake of food and nutrition plays a major role in affecting aging process and longevity. However, the precise mechanisms underlying the ageing process are still unclear. To this respect, diet has been considered to be a determinant of ageing process. In order to better illustrate this, we used Drosophila melanogaster as a model and fed them orally with different concentrations of two commonly used Indian medicinal plant products, Curcuma longa (rhizome) and Emblica officinalis (fruit). The results revealed significant increase in life span of Drosophila flies on exposure to both the plant products, more efficiently by C. Longa than by E. officinalis. In order to understand whether the increase in lifespan was due to high-antioxidant properties of these medicinal plants, we performed enzymatic assays to assess the SOD and catalase activities in case of both treated and control Drosophila flies. Interestingly, the results support the free radical theory of aging as both these plant derivatives show high reactive oxygen species (ROS) scavenging activities. PMID:24967413

Rawal, Shilpa; Singh, Pavneet; Gupta, Ayush; Mohanty, Sujata

2014-01-01

157

Abnormal tissue proliferation and life span variability in chronically irradiated dogs.  

PubMed

Data extracted from the ? Beagle Dog Tissue Archive hosted by the Woloschak Laboratory (Chicago, IL, USA) were used in a retrospective comparative study of the influence of associated morbidities on the ability of organisms to regenerate hematopoietic cells. There were 209 dogs that had been subjected to whole-body irradiation from a cobalt 60 source from 1.1 years of age until death, with dose rates of 0.003-0.038 Gy/day. One hundred fifty-six nonirradiated dogs served as controls. The presence of neoplasms clinically recorded during each dog's lifetime (uncertain benign or malignant nature) was used to assign experimental subjects and controls to one of two groups: W (with) and WO (without) lesions. Differences between the two groups were noted, mainly a longer average life span and a prevalence of solid malignancy over malignant hematopoiesis in both irradiated and nonirradiated W dogs. We propose an interpretation of these data as showing variability of the activity of tissue-committed hematopoietic stem cells, reflected not only by an increased incidence of solid benign and malignant tumors, but also by greater marrow radioresistance and a stronger viability of W cohorts. PMID:24310526

Shoutko, A N; Ekimova, L P

2014-03-01

158

Atrx deficiency induces telomere dysfunction, endocrine defects, and reduced life span  

PubMed Central

Human ATRX mutations are associated with cognitive deficits, developmental abnormalities, and cancer. We show that the Atrx-null embryonic mouse brain accumulates replicative damage at telomeres and pericentromeric heterochromatin, which is exacerbated by loss of p53 and linked to ATM activation. ATRX-deficient neuroprogenitors exhibited higher incidence of telomere fusions and increased sensitivity to replication stressinducing drugs. Treatment of Atrx-null neuroprogenitors with the G-quadruplex (G4) ligand telomestatin increased DNA damage, indicating that ATRX likely aids in the replication of telomeric G4-DNA structures. Unexpectedly, mutant mice displayed reduced growth, shortened life span, lordokyphosis, cataracts, heart enlargement, and hypoglycemia, as well as reduction of mineral bone density, trabecular bone content, and subcutaneous fat. We show that a subset of these defects can be attributed to loss of ATRX in the embryonic anterior pituitary that resulted in low circulating levels of thyroxine and IGF-1. Our findings suggest that loss of ATRX increases DNA damage locally in the forebrain and anterior pituitary and causes tissue attrition and other systemic defects similar to those seen in aging. PMID:23563309

Watson, L. Ashley; Solomon, Lauren A.; Li, Jennifer Ruizhe; Jiang, Yan; Edwards, Matthew; Shin-ya, Kazuo; Beier, Frank; Brub, Nathalie G.

2013-01-01

159

Atrx deficiency induces telomere dysfunction, endocrine defects, and reduced life span.  

PubMed

Human ATRX mutations are associated with cognitive deficits, developmental abnormalities, and cancer. We show that the Atrx-null embryonic mouse brain accumulates replicative damage at telomeres and pericentromeric heterochromatin, which is exacerbated by loss of p53 and linked to ATM activation. ATRX-deficient neuroprogenitors exhibited higher incidence of telomere fusions and increased sensitivity to replication stress-inducing drugs. Treatment of Atrx-null neuroprogenitors with the G-quadruplex (G4) ligand telomestatin increased DNA damage, indicating that ATRX likely aids in the replication of telomeric G4-DNA structures. Unexpectedly, mutant mice displayed reduced growth, shortened life span, lordokyphosis, cataracts, heart enlargement, and hypoglycemia, as well as reduction of mineral bone density, trabecular bone content, and subcutaneous fat. We show that a subset of these defects can be attributed to loss of ATRX in the embryonic anterior pituitary that resulted in low circulating levels of thyroxine and IGF-1. Our findings suggest that loss of ATRX increases DNA damage locally in the forebrain and anterior pituitary and causes tissue attrition and other systemic defects similar to those seen in aging. PMID:23563309

Watson, L Ashley; Solomon, Lauren A; Li, Jennifer Ruizhe; Jiang, Yan; Edwards, Matthew; Shin-ya, Kazuo; Beier, Frank; Brub, Nathalie G

2013-05-01

160

The decline of verbal and visuospatial working memory across the adult life span.  

PubMed

It has been well established that working memory abilities decrease with advancing age; however, the specific time point in the adult life span at which this deficit begins and the rate at which it advances are still controversial. There is no agreement on whether working memory declines equally for visuospatial and verbal information, and the literature disagrees on how task difficulty may influence this decay. We addressed these questions in a lifespan sample of 1,500 participants between 21 and 80 years old. The n-back task was used, with letters and circles presented at different positions around an imaginary circle, to evaluate working memory in the verbal and visuospatial domains, respectively. The participants' task was to judge whether the current stimulus matched a stimulus that was shown n trials prior. Both domains were evaluated in two levels of difficulty: 1-back and 2-back. The comparison across decades showed that discrimination in the visuospatial and 1-back tasks started to decline earlier in women than in men; however, discrimination was equal between the sexes in the verbal and 2-back tasks. Performance on tasks in the visuospatial domain exhibited more pronounced decline than in those in the verbal domain. The rate of decline in working memory accuracy was superior in 2-back tasks than in 1-back tasks, independent of the domain. These results revealed that the effects of aging on working memory are less dependent on the type of information and more reliant on the resources demanded by the task. PMID:23558670

Cansino, Selene; Hernndez-Ramos, Evelia; Estrada-Manilla, Cinthya; Torres-Trejo, Frine; Martnez-Galindo, Joyce Graciela; Ayala-Hernndez, Mariana; Gmez-Fernndez, Tania; Osorio, David; Cedillo-Tinoco, Melisa; Garcs-Flores, Lissete; Beltrn-Palacios, Karla; Garca-Lzaro, Hayde Guadalupe; Garca-Gutirrez, Fabiola; Cadena-Arenas, Yadira; Fernndez-Apan, Luisa; Brtschi, Andrea; Rodrguez-Ortiz, Mara Dolores

2013-12-01

161

HIV1 dynamics in vivo: Virion clearance rate, infected cell life-span, and viral generation time  

Microsoft Academic Search

A new mathematical model was used to analyze a detailed set of human immunodeficiency virus-type 1 (HIV-1) viral load data collected from five infected individuals after the administration of a potent inhibitor of HIV-1 protease. Productively infected cells were estimated to have, on average, a life-span of 2.2 days (half-life t = 1.6 days), and plasma virions were estimated to

A. S. Perelson; A. U. Neumann; M. Markowitz; D. D. Ho; J. M. Leonard

1996-01-01

162

Modeling Life-Span Growth Curves of Cognition Using Longitudinal Data with Multiple Samples and Changing Scales of Measurement  

ERIC Educational Resources Information Center

The authors use multiple-sample longitudinal data from different test batteries to examine propositions about changes in constructs over the life span. The data come from 3 classic studies on intellectual abilities in which, in combination, 441 persons were repeatedly measured as many as 16 times over 70 years. They measured cognitive constructs

McArdle, John J.; Grimm, Kevin J.; Hamagami, Fumiaki; Bowles, Ryan P.; Meredith, William

2009-01-01

163

Oxidative Stress Tolerance, Adenylate Cyclase, and Autophagy Are Key Players in the Chronological Life Span of Saccharomyces cerevisiae during Winemaking  

PubMed Central

Most grape juice fermentation takes place when yeast cells are in a nondividing state called the stationary phase. Under such circumstances, we aimed to identify the genetic determinants controlling longevity, known as the chronological life span. We identified commercial strains with both short (EC1118) and long (CSM) life spans in laboratory growth medium and compared them under diverse conditions. Strain CSM shows better tolerance to stresses, including oxidative stress, in the stationary phase. This is reflected during winemaking, when this strain has an increased maximum life span. Compared to EC1118, CSM overexpresses a mitochondrial rhodanese gene-like gene, RDL2, whose deletion leads to increased reactive oxygen species production at the end of fermentation and a correlative loss of viability at this point. EC1118 shows faster growth and higher expression of glycolytic genes, and this is related to greater PKA activity due to the upregulation of the adenylate cyclase gene. This phenotype has been linked to the presence of a ? element in its promoter, whose removal increases the life span. Finally, EC1118 exhibits a higher level of protein degradation by autophagy, which might help achieve fast growth at the expense of cellular structures and may be relevant for long-term survival under winemaking conditions. PMID:22327582

Orozco, Helena; Matallana, Emilia

2012-01-01

164

Comparison of Leaf Life Span, Photosynthesis and Defensive Traits Across Seven Species of Deciduous Broad-leaf Tree Seedlings  

Microsoft Academic Search

? Background and Aims Leaf life span, photosynthetic parameters and defensive traits were compared across seven species of deciduous broad-leaved tree seedlings native to northern Japan to test the 'cost-benefit hypothesis' that more productive leaves are more susceptible to herbivore attack than less productive leaves. ? Methods Studies were made on three early successional species, Alnus hirsuta, Betula maximowicziana and

SAWAKO M ATSUKI; T AKAYOSHI K OIKE

2006-01-01

165

Reconstitution of telomerase activity in normal human cells leads to elongation of telomeres and extended replicative life span  

Microsoft Academic Search

Normal somatic cells have a finite life span [1] and lose telomeric DNA, present at the ends of chromosomes, each time they divide as a function of age in vivo or in culture [24]. In contrast, many cancer cells and cell lines established from tumours maintain their telomere length by activation of an RNAprotein complex called telomerase, an enzyme originally

Homayoun Vaziri; Samuel Benchimol

1998-01-01

166

Estimating age-dependent costs and benefits of roots with contrasting life span: comparing apples and oranges  

Microsoft Academic Search

The relation between root age and root function is poorly understood, despite its importance to root longevity. The effect of root age on respiration rates and P-32-uptake kinetics was determined for roots excavated from mature apple and citrus trees (median root life spans of 30 vs 300 d). To evaluate whether root longevity maximizes the efficiency of nutrient capture, daily

Tjeerd J. Bouma; Ruth D. Yanai; Adrienne D. Elkin; Ulrich Hartmond; Dora E. Flores-Alva; David M. Eissenstat

2001-01-01

167

Copyright 2000 by the Genetics Society of America Quantitative Trait Loci for Life Span in Drosophila melanogaster  

E-print Network

in aging, determining their and how the genetic components interact with environ- age- and environmentCopyright © 2000 by the Genetics Society of America Quantitative Trait Loci for Life Span in Drosophila melanogaster: Interactions With Genetic Background and Larval Density Jeff Leips and Trudy F. C

Mackay, Trudy F.C.

168

Changes in Acoustic Characteristics of the Voice across the Life Span: Measures from Individuals 4-93 Years of Age  

ERIC Educational Resources Information Center

Purpose: The purpose of the present investigation was to examine acoustic voice changes across the life span. Previous voice production investigations used small numbers of participants, had limited age ranges, and produced contradictory results. Method: Voice recordings were made from 192 male and female participants 4-93 years of age. Acoustic

Stathopoulos, Elaine T.; Huber, Jessica E.; Sussman, Joan E.

2011-01-01

169

Tor1/Sch9-Regulated Carbon Source Substitution Is as Effective as Calorie Restriction in Life Span Extension  

PubMed Central

The effect of calorie restriction (CR) on life span extension, demonstrated in organisms ranging from yeast to mice, may involve the down-regulation of pathways, including Tor, Akt, and Ras. Here, we present data suggesting that yeast Tor1 and Sch9 (a homolog of the mammalian kinases Akt and S6K) is a central component of a network that controls a common set of genes implicated in a metabolic switch from the TCA cycle and respiration to glycolysis and glycerol biosynthesis. During chronological survival, mutants lacking SCH9 depleted extracellular ethanol and reduced stored lipids, but synthesized and released glycerol. Deletion of the glycerol biosynthesis genes GPD1, GPD2, or RHR2, among the most up-regulated in long-lived sch9?, tor1?, and ras2? mutants, was sufficient to reverse chronological life span extension in sch9? mutants, suggesting that glycerol production, in addition to the regulation of stress resistance systems, optimizes life span extension. Glycerol, unlike glucose or ethanol, did not adversely affect the life span extension induced by calorie restriction or starvation, suggesting that carbon source substitution may represent an alternative to calorie restriction as a strategy to delay aging. PMID:19424415

Madia, Federica; Hu, Jia; Ge, Huanying; Li, Lei M.; Longo, Valter D.

2009-01-01

170

The Genetic Architecture of Life Span and Mortality Rates: Gender and Species Differences in Inbreeding Load of Two Seed-Feeding Beetles  

PubMed Central

We examine the inbreeding load for adult life span and mortality rates of two seed beetle species, Callosobruchus maculatus and Stator limbatus. Inbreeding load differs substantially between males and females in both study populations of C. maculatuslife span of inbred females was 913% shorter than the life span of outbred females, whereas the life span of inbred males did not differ from the life span of outbred males. The effect of inbreeding on female life span was largely due to an increase in the slope of the mortality curve. In contrast, inbreeding had only a small effect on the life span of S. limbatuslife spans of inbred beetles were ?5% shorter than those of outbred beetles, and there was no difference in inbreeding load between the sexes. The inbreeding load for mean life span was ?0.40.6 lethal equivalents per haploid gamete for female C. maculatus and ?0.20.3 for both males and females of S. limbatus, all within the range of estimates commonly obtained for Drosophila. However, contrary to the predictions of mutation-accumulation models, inbreeding load for loci affecting mortality rates did not increase with age in either species, despite an effect of inbreeding on the initial rate of increase in mortality. This was because mortality rates decelerated with age and converged to a mortality plateau for both outbred and inbred beetles. PMID:16888331

Fox, Charles W.; Scheibly, Kristy L.; Wallin, William G.; Hitchcock, Lisa J.; Stillwell, R. Craig; Smith, Benjamin P.

2006-01-01

171

A Functional Analysis Reveals Dependence on the Anaphase-Promoting Complex for Prolonged Life Span in Yeast  

PubMed Central

Defects in anaphase-promoting complex (APC) activity, which regulates mitotic progression and chromatin assembly, results in genomic instability, a hallmark of premature aging and cancer. We investigated whether APC-dependent genomic stability affects aging and life span in yeast. Utilizing replicative and chronological aging assays, the APC was shown to promote longevity. Multicopy expression of genes encoding Snf1p (MIG1) and PKA (PDE2) aging-pathway components suppressed apc5CA phenotypes, suggesting their involvement in APC-dependent longevity. While it is known that PKA inhibits APC activity and reduces life span, a link between the Snf1p-inhibited Mig1p transcriptional modulator and the APC is novel. Our mutant analysis supports a model in which Snf1p promotes extended life span by inhibiting the negative influence of Mig1p on the APC. Consistent with this, we found that increased MIG1 expression reduced replicative life span, whereas mig1? mutations suppressed the apc5CA chronological aging defect. Furthermore, Mig1p and Mig2p activate APC gene transcription, particularly on glycerol, and mig2?, but not mig1?, confers a prolonged replicative life span in both APC5 and acp5CA cells. However, glucose repression of APC genes was Mig1p and Mig2p independent, indicating the presence of an uncharacterized factor. Therefore, we propose that APC-dependent genomic stability is linked to prolonged longevity by the antagonistic regulation of the PKA and Snf1p pathways. PMID:15514051

Harkness, Troy A. A.; Shea, Kyla A.; Legrand, Charmaine; Brahmania, Mayur; Davies, Gerald F.

2004-01-01

172

Sex differences in aging, life span and spontaneous tumorigenesis in 129/Sv mice neonatally exposed to metformin.  

PubMed

The perinatal (prenatal and early neonatal) period is a critical stage for hypothalamic programming of sexual differentiation as well as for the development of energy and metabolic homeostasis. We hypothesized that neonatal treatment with antidiabetic drug biguanide metformin would positively modify regulation of growth hormone - IGF-1 - insulin signaling pathway slowing down aging and improving cancer preventive patterns in rodents. To test this hypothesis male and female 129/Sv mice were s.c. injected with metformin (100mg/kg) at the 3rd, 5th and 7th days after birth. Metformin-treated males consumed less food and water and their body weight was decreased as compared with control mice practically over their entire lifespan. There were no significant differences in age-related dynamics of food and water consumption in females and they were heavier than controls. The fraction of mice with regular estrous cycles decreased with age and demonstrated a tendency to decrease in the females neonatally treated with metformin. Neonatal exposure to metformin practically failed to change the extent of hormonal and metabolic parameters in blood serum of male and female mice. In males, neonatal metformin treatment significantly increased the mean life span (+20%, P < 0.05) and slightly increased the maximum life span (+3.5%). In females, the mean life span and median in metformin-treated groups were slightly decreased (-9.1% and -13.8% respectively, P > 0.05) in comparison to controls, whereas mean life span of last 10% survivors and maximum life span were the same as in controls. Almost half (45%) of control male mice and 71.8% male mice neonatally exposed to metformin survived up to 800 d of age, the same age was achieved by 54.3% of mice in control female group and 30% of metformin-treated females (P < 0.03). Thus, neonatal metformin exposure slows down aging and prolongs lifespan in male but not in female mice. PMID:25483062

Anisimov, Vladimir N; Popovich, Irina G; Zabezhinski, Mark A; Egormin, Peter A; Yurova, Maria N; Semenchenko, Anna V; Tyndyk, Margarita L; Panchenko, Andrey V; Trashkov, Alexandr P; Vasiliev, Andrey G; Khaitsev, Nikolai V

2015-01-01

173

Life span and tissue distribution of 111indium-labeled blood platelets in hypomagnesemic lambs  

SciTech Connect

Circulating platelets may be activated by exposed triple-helical collagen in atherosclerotic lesions in Mg-deficient ruminants. Autologous platelets, labeled in vitro with 111In and determined to be active, were injected into 5 hypomagnesemic and 3 control lambs fed semipurified diets with 100 or 2,000 mg of Mg/kg of feed for 3 months. During the first 68 hours, 111In concentrations were 11 times higher in packed cells than in plasma. Packed-cell 111In increased 60% during the first 2 hours, probably due to initial tissue sequestration and later release of labeled platelets. Thereafter, platelet half-life span averaged 60 and 63 hours for hypomagnesemic and control lambs. After 68 hours, lambs were injected with native vascular collagen fibrils at 500 micrograms/kg of body weight to initiate reversible platelet aggregation. Within 1 minute, 83% of packed-cell 111In disappeared from circulation. Thirty minutes later, the lambs were euthanatized and necropsied and in the lungs, liver, and spleen, 111In averaged 24%, 19%, and 9%, respectively, of 111In injected 68 hours earlier. Organ deposits were not affected by Mg intake, but 111In in the lungs was somewhat lower in 2 lambs injected with inactivated collagen. Pathologic changes induced by reversible platelet aggregation were compatible with right ventricular failure complicated by pulmonary edema, similar to changes in hypomagnesemic lambs that died spontaneously. Platelets in blood exposed to vascular lesions in hypomagnesemic ruminants could be a major mortality risk factor in grass tetany disease.

Schneider, M.D.; Miller, J.K.; White, P.K.; Ramsey, N.

1983-05-01

174

Missing doses in the life span study of Japanese atomic bomb survivors.  

PubMed

The Life Span Study of atomic bomb survivors is an important source of risk estimates used to inform radiation protection and compensation. Interviews with survivors in the 1950s and 1960s provided information needed to estimate radiation doses for survivors proximal to ground zero. Because of a lack of interview or the complexity of shielding, doses are missing for 7,058 of the 68,119 proximal survivors. Recent analyses excluded people with missing doses, and despite the protracted collection of interview information necessary to estimate some survivors' doses, defined start of follow-up as October 1, 1950, for everyone. We describe the prevalence of missing doses and its association with mortality, distance from hypocenter, city, age, and sex. Missing doses were more common among Nagasaki residents than among Hiroshima residents (prevalence ratio = 2.05; 95% confidence interval: 1.96, 2.14), among people who were closer to ground zero than among those who were far from it, among people who were younger at enrollment than among those who were older, and among males than among females (prevalence ratio = 1.22; 95% confidence interval: 1.17, 1.28). Missing dose was associated with all-cancer and leukemia mortality, particularly during the first years of follow-up (all-cancer rate ratio = 2.16, 95% confidence interval: 1.51, 3.08; and leukemia rate ratio = 4.28, 95% confidence interval: 1.72, 10.67). Accounting for missing dose and late entry should reduce bias in estimated dose-mortality associations. PMID:23429722

Richardson, David B; Wing, Steve; Cole, Stephen R

2013-03-15

175

Missing Doses in the Life Span Study of Japanese Atomic Bomb Survivors  

PubMed Central

The Life Span Study of atomic bomb survivors is an important source of risk estimates used to inform radiation protection and compensation. Interviews with survivors in the 1950s and 1960s provided information needed to estimate radiation doses for survivors proximal to ground zero. Because of a lack of interview or the complexity of shielding, doses are missing for 7,058 of the 68,119 proximal survivors. Recent analyses excluded people with missing doses, and despite the protracted collection of interview information necessary to estimate some survivors' doses, defined start of follow-up as October 1, 1950, for everyone. We describe the prevalence of missing doses and its association with mortality, distance from hypocenter, city, age, and sex. Missing doses were more common among Nagasaki residents than among Hiroshima residents (prevalence ratio = 2.05; 95% confidence interval: 1.96, 2.14), among people who were closer to ground zero than among those who were far from it, among people who were younger at enrollment than among those who were older, and among males than among females (prevalence ratio = 1.22; 95% confidence interval: 1.17, 1.28). Missing dose was associated with all-cancer and leukemia mortality, particularly during the first years of follow-up (all-cancer rate ratio = 2.16, 95% confidence interval: 1.51, 3.08; and leukemia rate ratio = 4.28, 95% confidence interval: 1.72, 10.67). Accounting for missing dose and late entry should reduce bias in estimated dose-mortality associations. PMID:23429722

Richardson, David B.; Wing, Steve; Cole, Stephen R.

2013-01-01

176

elf-reproduction is central to biological life for long-term sustainability and  

E-print Network

S elf-reproduction is central to biological life for long-term sustainability and evolutionary- reproduction have not been exploited in machine design1 . Here we create simple machines that act as autonomous modular robots and are capable of physical self- reproduction using a set of cubes. A physical system

Napp, Nils

177

Life-Span Extension in Mice by Preweaning Food Restriction and by Methionine Restriction in Middle Age  

PubMed Central

Life span can be extended in rodents by restricting food availability (caloric restriction [CR]) or by providing food low in methionine (Meth-R). Here, we show that a period of food restriction limited to the first 20 days of life, via a 50% enlargement of litter size, shows extended median and maximal life span relative to mice from normal sized litters and that a Meth-R diet initiated at 12 months of age also significantly increases longevity. Furthermore, mice exposed to a CR diet show changes in liver messenger RNA patterns, in phosphorylation of Erk, Jnk2, and p38 kinases, and in phosphorylation of mammalian target of rapamycin and its substrate 4EBP1, HE-binding protein 1 that are not observed in liver from age-matched Meth-R mice. These results introduce new protocols that can increase maximal life span and suggest that the spectrum of metabolic changes induced by low-calorie and low-methionine diets may differ in instructive ways. PMID:19414512

Sun, Liou; Sadighi Akha, Amir A.; Miller, Richard A.

2009-01-01

178

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

ERIC Educational Resources Information Center

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

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

179

Life span of patients with Eisenmenger syndrome is not superior to that of patients with other causes of pulmonary hypertension  

PubMed Central

Background Patients with Eisenmenger syndrome (ES) carry a better prognosis from diagnosis than patients with other causes of pulmonary hypertension (PH), but their life span has not yet been clarified. Aims To clarify both survival from diagnosis and life span in ES, and in closed shunt with pulmonary arterial hypertension (PAH), as compared with other causes of PH. Methods Data on all adult patients with PH attending our centre over the past decade was collected. Outcome was defined as death or transplantation. Results We studied 149 patients, including 30 (20%) patients with ES and 12 (8%) patients with closed shunt with PAH. Median age at diagnosis was lower for patients with ES and closed-shunt with PAH compared to patients with other causes of PH (P<0.001 and P=0.008 respectively). Median follow-up was 4.25 years. Survival from diagnosis was longer in ES compared to other causes of PH (logrank; P=0.02) and similar between closed-shunt with PAH and other causes of PH (logrank; P=0.3). Survival rates at 3, 6 and 9 years from diagnosis were: 73%, 50% and 47% for ES, 75%, 25% and 0% for closed-shunt with PAH, 65%, 23% and 9% for other causes of PH. Life span was similar in those three groups (logrank; P=0.2 and P=0.7, respectively). Conclusions Life span is similar in patients with ES, with a closed-shunt associated with PAH, and in patients with other causes of PH. PMID:25414820

Renard, Sbastien; Mancini, Julien; Hubert, Sandrine; Habib, Gilbert; Fraisse, Alain

2014-01-01

180

Ageing in a eusocial insect: molecular and physiological characteristics of life span plasticity in the honey bee  

PubMed Central

Summary Commonly held views assume that ageing, or senescence, represents an inevitable, passive, and random decline in function that is strongly linked to chronological age. In recent years, genetic intervention of life span regulating pathways, for example, in Drosophila as well as case studies in non-classical animal models, have provided compelling evidence to challenge these views. Rather than comprehensively revisiting studies on the established genetic model systems of ageing, we here focus on an alternative model organism with a wild type (unselected genotype) characterized by a unique diversity in longevity the honey bee. Honey bee (Apis mellifera) life span varies from a few weeks to more than 2 years. This plasticity is largely controlled by environmental factors. Thereby, although individuals are closely related genetically, distinct life histories can emerge as a function of social environmental change. Another remarkable feature of the honey bee is the occurrence of reverted behavioural ontogeny in the worker (female helper) caste. This behavioural peculiarity is associated with alterations in somatic maintenance functions that are indicative of reverted senescence. Thus, although intraspecific variation in organismal life span is not uncommon, the honey bee holds great promise for gaining insights into regulatory pathways that can shape the time-course of ageing by delaying, halting or even reversing processes of senescence. These aspects provide the setting of our review. We will highlight comparative findings from Drosophila melanogaster and Caenorhabditis elegans in particular, and focus on knowledge spanning from molecular- to behavioural-senescence to elucidate how the honey bee can contribute to novel insights into regulatory mechanisms that underlie plasticity and robustness or irreversibility in ageing. PMID:18728759

Mnch, D.; Amdam, G. V.; Wolschin, F.

2008-01-01

181

Deleting the 14-3-3 Protein Bmh1 Extends Life Span in Saccharomyces cerevisiae by Increasing Stress Response  

Microsoft Academic Search

Enhanced stress response has been suggested to promote longevity in many species. Calorie restriction (CR) and conserved nutrient-sensing target of rapamycin (TOR) and protein kinase A (PKA) pathways have also been suggested to extend life span by increasing stress response, which protects cells from age- dependent accumulation of oxidative damages. Here we show that deleting the yeast 14-3-3 protein, Bmh1,

Chen Wang; Craig Skinner; Erin Easlon; Su-Ju Lin

2009-01-01

182

Effect of metformin on life span and on the development of spontaneous mammary tumors in HER2\\/neu transgenic mice  

Microsoft Academic Search

Studies in mammals have led to the suggestion that hyperglycemia and hyperinsulinemia are important factors both in aging and in the development of cancer. Insulin\\/insulin-like growth factor 1 (IGF-1) signaling molecules that have been linked to longevity include DAF-2 and InR and their homologues in mammals, and inactivation of the corresponding genes is followed by increased life span in nematodes,

Vladimir N. Anisimov; Lev M. Berstein; Peter A. Egormin; Tatiana S. Piskunova; Irina G. Popovich; Mark A. Zabezhinski; Irina G. Kovalenko; Tatiana E. Poroshina; Anna V. Semenchenko; Mauro Provinciali; Francesca Re; Claudio Franceschi

2005-01-01

183

Tor1\\/Sch9-Regulated Carbon Source Substitution Is as Effective as Calorie Restriction in Life Span Extension  

Microsoft Academic Search

The effect of calorie restriction (CR) on life span extension, demonstrated in organisms ranging from yeast to mice, may involve the down-regulation of pathways, including Tor, Akt, and Ras. Here, we present data suggesting that yeast Tor1 and Sch9 (a homolog of the mammalian kinases Akt and S6K) is a central component of a network that controls a common set

Min Wei; Paola Fabrizio; Federica Madia; Jia Hu; Huanying Ge; Lei M. Li; Valter D. Longo

2009-01-01

184

The extended life span of Drosophila melanogaster eye-color (white and vermilion) mutants with impaired formation of kynurenine.  

PubMed

Animal and human studies suggest that aging is associated with increased formation of kynurenine (KYN) from tryptophan (TRY). The rate-limiting factors of TRY-KYN metabolism are transmembrane transport of TRY, and activity of enzyme, TRY 2,3-dioxygenase (TDO2). Eye-color mutants, white (w1118) (impaired TRY transport) and vermilion (v48a and v2) (deficient TDO activity), were compared with wild-type Oregon-R (Ore-R) strain of Drosophila melanogaster. Female 1-day-old adult flies maintained on a standard medium, and acclimatized to 12-h light:12-h dark cycle were collected, and then regularly transferred to fresh medium every 3-4 days. The number of dead flies was recorded at the time of transfer. Forty flies were studied in each experimental group. The life span of w1118 (mean = 45.5 days), and v48a (mean = 47.6 days) and v2 (mean = 43.8 days), were significantly longer than of wild-type Ore-R flies (27.1 days) (p < 0.001, Logrank test). There were no differences in life span between w1118 and v48a and v2 mutants. Present results suggest that prolongation of life span may be associated with slow rate of KYN formation from TRY. PMID:19941150

Oxenkrug, Gregory F

2010-01-01

185

Influence of early-life nutrition on mortality and reproductive success during a subsequent famine  

E-print Network

-life conditions, no study on humans has demonstrated the predicted fitness benefit under low later-life nutrition of metabolic diseases. developmental plasticity | silver spoon | human life-history | DoHAD Nutrition duringInfluence of early-life nutrition on mortality and reproductive success during a subsequent famine

Lummaa, Virpi

186

The Structure of Working Memory Abilities across the Adult Life Span  

PubMed Central

The present study addresses three questions regarding age differences in working memory: (1) whether performance on complex span tasks decreases as a function of age at a faster rate than performance on simple span tasks; (2) whether spatial working memory decreases at a faster rate than verbal working memory; and (3) whether the structure of working memory abilities is different for different age groups. Adults, ages 2089 (n=388), performed three simple and three complex verbal span tasks and three simple and three complex spatial memory tasks. Performance on the spatial tasks decreased at faster rates as a function of age than performance on the verbal tasks, but within each domain, performance on complex and simple span tasks decreased at the same rates. Confirmatory factor analyses revealed that domain-differentiated models yielded better fits than models involving domain-general constructs, providing further evidence of the need to distinguish verbal and spatial working memory abilities. Regardless of which domain-differentiated model was examined, and despite the faster rates of decrease in the spatial domain, age group comparisons revealed that the factor structure of working memory abilities was highly similar in younger and older adults and showed no evidence of age-related dedifferentiation. PMID:21299306

Hale, Sandra; Rose, Nathan S.; Myerson, Joel; Strube, Michael J; Sommers, Mitchell; Tye-Murray, Nancy; Spehar, Brent

2010-01-01

187

16. Hansen, M., Flatt, T., and Aguilaniu, H. (2013). Reproduction, fat metabolism, and life span  

E-print Network

Biology by Leyva-Diaz et al. [4] provides insights into this important question by demonstrating protein FLRT3. The study by Leyva-Diaz et al. [4] builds on previous work from Bielle et al. [8], which

Lowery, Laura Anne

188

Extension of Life Span by Impaired Glucose Metabolism in Caenorhabditis elegans Is Accompanied by Structural Rearrangements of the Transcriptomic Network  

PubMed Central

Glucose restriction mimicked by feeding the roundworm Caenorhabditis elegans with 2-deoxy-D-glucose (DOG) - a glucose molecule that lacks the ability to undergo glycolysis - has been found to increase the life span of the nematodes considerably. To facilitate understanding of the molecular mechanisms behind this life extension, we analyzed transcriptomes of DOG-treated and untreated roundworms obtained by RNA-seq at different ages. We found that, depending on age, DOG changes the magnitude of the expression values of about 2 to 24 percent of the genes significantly, although our results reveal that the gross changes introduced by DOG are small compared to the age-induced changes. We found that 27 genes are constantly either up- or down-regulated by DOG over the whole life span, among them several members of the cytochrome P450 family. The monotonic change with age of the temporal expression patterns of the genes was investigated, leading to the result that 21 genes reverse their monotonic behaviour under impaired glycolysis. Put simply, the DOG-treatment reduces the gross transcriptional activity but increases the interconnectedness of gene expression. However, a detailed analysis of network parameters discloses that the introduced changes differ remarkably between individual signalling pathways. We found a reorganization of the hubs of the mTOR pathway when standard diet is replaced by DOG feeding. By constructing correlation based difference networks, we identified those signalling pathways that are most vigorously changed by impaired glycolysis. Taken together, we have found a number of genes and pathways that are potentially involved in the DOG-driven extension of life span of C. elegans. Furthermore, our results demonstrate how the network structure of ageing-relevant signalling pathways is reorganised under impaired glycolysis. PMID:24204961

Priebe, Steffen; Menzel, Uwe; Zarse, Kim; Groth, Marco; Platzer, Matthias; Ristow, Michael; Guthke, Reinhard

2013-01-01

189

A major QTL affects temperature sensitive adult lethality and inbreeding depression in life span in Drosophila melanogaster  

PubMed Central

Background The study of inbreeding depression has major relevance for many disciplines, including conservation genetics and evolutionary biology. Still, the molecular genetic basis of this phenomenon remains poorly characterised, as knowledge on the mechanistic causes of inbreeding depression and the molecular properties of genes that give rise to or modulate its deleterious effects is lacking. These questions warrant the detailed study of genetic loci giving rise to inbreeding depression. However, the complex and polygenic nature of general inbreeding depression makes this a daunting task. Study of inbreeding effects in specific traits, such as age-specific mortality and life span, provide a good starting point, as a limited set of genes is expected to be involved. Results Here we report on a QTL mapping study on inbreeding related and temperature sensitive lethality in male Drosophila melanogaster. The inbreeding effect was expressed at moderately high temperature, and manifested itself as severe premature mortality in males, but not in females. We used a North Carolina crossing design 3 to estimate average dominance ratio and heritability. We found the genetic basis of the lethal effect to be relatively simple, being due mainly to a single recessive QTL on the left arm of chromosome 2. This locus colocalised with a QTL that conditioned variation in female life span, acting as an overdominant locus for this trait. Male life span was additionally affected by variation at the X-chromosome. Conclusion This demonstrates that analysis of large conditional lethal effects is a viable strategy for delineating genes which are sensitive to inbreeding depression. PMID:18957085

2008-01-01

190

The paradox of the short life span of organisms with long telomeres: A possible solution to this paradox  

SciTech Connect

Earlier we proposed an idea about the direct proportional dependence between the length of buffer DNA at the ends of chromosomes, i.e., telomeric DNA, and the life span of organisms. In these publications, we predicted the phenomenon of shortening of telomeric DNA as a result of under-replication (incomplete replication) of terminal DNA sequences. In this study, we try to demonstrate that this shortening of telomeric DNA may indeed be a leading factor in the process of fibroblast aging. 12 refs.

Olovnikov, A.M. [Semenov Institute of Chemical Physics, Moscow (Russian Federation)

1995-07-01

191

Comparison of Building Energy Efficiency and Life Span for Different Envelopes  

E-print Network

heat insulation measurement and heat preservation material position brings wall flaws and building life reduction. Comparisons of two building envelope heat insulation features are carried out by physical parameter measurements and calculation...

Li, Z.; Li, D.; Li, L.; Zhang, G.; Liu, J.

2006-01-01

192

Variability in Reproductive Success Viewed From a Life-History Perspective in Baboons  

E-print Network

Variability in Reproductive Success Viewed From a Life-History Perspective in Baboons JEANNE- tribute to within-population variance in reproductive success for savannah baboons. We also discuss the extent to which savannah baboons, with their highly flexible and adaptable behavior, change

Alberts, Susan C

193

Plant Reproduction. Plant Life in Action[TM]. Schlessinger Science Library. [Videotape].  

ERIC Educational Resources Information Center

Plants are vital to all other life on this planet - without them, there would be no food, shelter or oxygen. Luckily, over millions of years plants have developed many different features in order to survive and reproduce. In Plant Reproduction, students will discover that primitive mosses and algae are dependent upon water for their reproduction.

2000

194

Fullness of Life as Minimal Unit: Science, Technology, Engineering, and Mathematics (STEM) Learning across the Life Span  

ERIC Educational Resources Information Center

Challenged by a National Science Foundation-funded conference, 2020 Vision: The Next Generation of STEM Learning Research, in which participants were asked to recognize science, technology, engineering, and mathematics (STEM) learning as lifelong, life-wide, and life-deep, we draw upon 20 years of research across the lifespan to propose a new way

Roth, Wolff-Michael; Van Eijck, Michiel

2010-01-01

195

Male personality, life-history strategies and reproductive success in a promiscuous mammal.  

PubMed

Recent theoretical work suggests that personality is a component of life history, but links between personality and either age-dependent reproductive success or life-history strategy are yet to be established. Using quantitative genetic analyses on a long-term pedigree we estimated indices of boldness and docility for 105 bighorn sheep rams (Ovis canadensis), born between 1983 and 1999, and compared these indices to their reproductive history from 2 years of age until death. Docility and boldness were highly heritable and negatively genetically correlated. Docile and bold rams survived longer than indocile and shy rams. Docility and boldness had a weak negative effect on reproductive success early in life, but a strong positive effect on older rams. Our findings highlight an important role of personality on reproductive success and suggest that personality could be an important component of life-history strategy. PMID:19555442

Rale, D; Martin, J; Coltman, D W; Poissant, J; Festa-Bianchet, M

2009-08-01

196

Life Span Extension by Calorie Restriction Depends on Rim15 and Transcription Factors Downstream of Ras\\/PKA, Tor, and Sch9  

Microsoft Academic Search

Calorie restriction (CR), the only non-genetic intervention known to slow aging and extend life span in organisms ranging from yeast to mice, has been linked to the down-regulation of Tor, Akt, and Ras signaling. In this study, we demonstrate that the serine\\/threonine kinase Rim15 is required for yeast chronological life span extension caused by deficiencies in Ras2, Tor1, and Sch9,

Min Wei; Paola Fabrizio; Jia Hu; Huanying Ge; Chao Cheng; Lei Li; Valter D Longo

2008-01-01

197

Telomerase-mediated life-span extension of human primary fibroblasts by human artificial chromosome (HAC) vector  

SciTech Connect

Telomerase-mediated life-span extension enables the expansion of normal cells without malignant transformation, and thus has been thought to be useful in cell therapies. Currently, integrating vectors including the retrovirus are used for human telomerase reverse transcriptase (hTERT)-mediated expansion of normal cells; however, the use of these vectors potentially causes unexpected insertional mutagenesis and/or activation of oncogenes. Here, we established normal human fibroblast (hPF) clones retaining non-integrating human artificial chromosome (HAC) vectors harboring the hTERT expression cassette. In hTERT-HAC/hPF clones, we observed the telomerase activity and the suppression of senescent-associated SA-{beta}-galactosidase activity. Furthermore, the hTERT-HAC/hPF clones continued growing beyond 120 days after cloning, whereas the hPF clones retaining the silent hTERT-HAC senesced within 70 days. Thus, hTERT-HAC-mediated episomal expression of hTERT allows the extension of the life-span of human primary cells, implying that gene delivery by non-integrating HAC vectors can be used to control cellular proliferative capacity of primary cultured cells.

Shitara, Shingo [Department of Biomedical Science, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Sciences, Tottori University, 86 Nishimachi, Yonago, Tottori 683-8503 (Japan); Kakeda, Minoru; Nagata, Keiko [Discovery Research Laboratories, Kirin Pharma Co., Ltd., 3 Miyahara-cho, Takasaki-shi, Gunma 370-1295 (Japan); Hiratsuka, Masaharu [Department of Biomedical Science, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Sciences, Tottori University, 86 Nishimachi, Yonago, Tottori 683-8503 (Japan); Sano, Akiko; Osawa, Kanako; Okazaki, Akiyo [Discovery Research Laboratories, Kirin Pharma Co., Ltd., 3 Miyahara-cho, Takasaki-shi, Gunma 370-1295 (Japan); Katoh, Motonobu; Kazuki, Yasuhiro; Oshimura, Mitsuo [Department of Biomedical Science, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Sciences, Tottori University, 86 Nishimachi, Yonago, Tottori 683-8503 (Japan); Tomizuka, Kazuma [Department of Biomedical Science, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Sciences, Tottori University, 86 Nishimachi, Yonago, Tottori 683-8503 (Japan); Discovery Research Laboratories, Kirin Pharma Co., Ltd., 3 Miyahara-cho, Takasaki-shi, Gunma 370-1295 (Japan)], E-mail: ktomizuka@kirin.co.jp

2008-05-09

198

Bmi-1 extends the life span of normal human oral keratinocytes by inhibiting the TGF-{beta} signaling  

SciTech Connect

We previously demonstrated that Bmi-1 extended the in vitro life span of normal human oral keratinocytes (NHOK). We now report that the prolonged life span of NHOK by Bmi-1 is, in part, due to inhibition of the TGF-{beta} signaling pathway. Serial subculture of NHOK resulted in replicative senescence and terminal differentiation and activation of TGF-{beta} signaling pathway. This was accompanied with enhanced intracellular and secreted TGF-{beta}1 levels, phosphorylation of Smad2/3, and increased expression of p15{sup INK4B} and p57{sup KIP2}. An ectopic expression of Bmi-1 in NHOK (HOK/Bmi-1) decreased the level of intracellular and secreted TGF-{beta}1 induced dephosphorylation of Smad2/3, and diminished the level of p15{sup INK4B} and p57{sup KIP2}. Moreover, Bmi-1 expression led to the inhibition of TGF-{beta}-responsive promoter activity in a dose-specific manner. Knockdown of Bmi-1 in rapidly proliferating HOK/Bmi-1 and cancer cells increased the level of phosphorylated Smad2/3, p15{sup INK4B}, and p57{sup KIP2}. In addition, an exposure of senescent NHOK to TGF-{beta} receptor I kinase inhibitor or anti-TGF-{beta} antibody resulted in enhanced replicative potential of cells. Taken together, these data suggest that Bmi-1 suppresses senescence of cells by inhibiting the TGF-{beta} signaling pathway in NHOK.

Kim, Reuben H., E-mail: rkim@dentistry.ucla.edu [UCLA School of Dentistry, Los Angeles, CA 90095 (United States); UCLA Dental Research Institute, Los Angeles, CA 90095 (United States); UCLA Jonsson Comprehensive Cancer Center, Los Angeles, CA 90095 (United States); Lieberman, Mark B.; Lee, Rachel [UCLA School of Dentistry, Los Angeles, CA 90095 (United States)] [UCLA School of Dentistry, Los Angeles, CA 90095 (United States); Shin, Ki-Hyuk [UCLA School of Dentistry, Los Angeles, CA 90095 (United States) [UCLA School of Dentistry, Los Angeles, CA 90095 (United States); UCLA Dental Research Institute, Los Angeles, CA 90095 (United States); UCLA Jonsson Comprehensive Cancer Center, Los Angeles, CA 90095 (United States); Mehrazarin, Shebli; Oh, Ju-Eun [UCLA School of Dentistry, Los Angeles, CA 90095 (United States)] [UCLA School of Dentistry, Los Angeles, CA 90095 (United States); Park, No-Hee [UCLA School of Dentistry, Los Angeles, CA 90095 (United States) [UCLA School of Dentistry, Los Angeles, CA 90095 (United States); UCLA Dental Research Institute, Los Angeles, CA 90095 (United States); UCLA Jonsson Comprehensive Cancer Center, Los Angeles, CA 90095 (United States); David Geffen School of Medicine at UCLA, Los Angeles, CA 90095 (United States); Kang, Mo K., E-mail: mkang@dentistry.ucla.edu [UCLA School of Dentistry, Los Angeles, CA 90095 (United States); UCLA Dental Research Institute, Los Angeles, CA 90095 (United States); UCLA Jonsson Comprehensive Cancer Center, Los Angeles, CA 90095 (United States)

2010-10-01

199

Extended life span of human endometrial stromal cells transfected with cloned origin-defective, temperature-sensitive simian virus 40.  

PubMed Central

Human endometrial stromal cells transfected with an origin-defective, temperature-sensitive simian virus 40 recombinant plasmid are dependent on T-antigen function for proliferation and at the permissive temperature have an extended life span in culture. Southern blot analysis indicates that the transfected gene is present in low copy number, possibly at a single integration site. Normal stromal cells are capable of 10 to 20 population doublings in culture. Transfected cultures have been carried at the permissive temperature to 80 population doublings before crisis. In the multistep model of malignant transformation of human cells, these cells represent one of the earliest stages: extended but finite life span. We have used these cells to investigate alterations in signal transduction that may be responsible for this early stage of transformation caused by the large T antigen. Temperature shift experiments indicate that the expression of ornithine decarboxylase (ODC) but not of c-fos is altered by the large T antigen. Induction of c-fos by serum or 12-O-tetradecanoylphorbol-13-acetate is independent of temperature. However, in the transfected cells, the induction of ODC by asparagine or serum is greatly enhanced at the permissive temperature. This result indicates that the large T antigen acts downstream of c-fos but upstream of ODC expression in the signal-transducing cascade. Images PMID:1847463

Rinehart, C A; Haskill, J S; Morris, J S; Butler, T D; Kaufman, D G

1991-01-01

200

Ethical Concerns in the Community About Technologies to Extend Human Life Span  

Microsoft Academic Search

Debates about the ethical and social implications of research that aims to extend human longevity by intervening in the ageing process have paid little attention to the attitudes of members of the general public. In the absence of empirical evidence, conflicting assumptions have been made about likely public attitudes towards life-extension. In light of recent calls for greater public involvement

Brad Partridge; Mair Underwood; Jayne Lucke; Helen Bartlett; Wayne Hall

2009-01-01

201

Life Span as the Measure of Performance and Learning in a Business Gaming Simulation  

ERIC Educational Resources Information Center

This study applies the learning curve method of measuring learning to participants of a computer-assisted business gaming simulation that includes a multiple-life-cycle feature. The study involved 249 participants. It verified the workability of the feature and estimated the participants' rate of learning at 17.4% for every doubling of experience.

Thavikulwat, Precha

2012-01-01

202

An extraordinary life span estimate for the clown anemonefish Amphiprion percula  

Microsoft Academic Search

A population of the clown anemonefish Amphiprion percula was studied for 1 year, in Madang Lagoon, Papua New Guinea. From this study, data on mortality events and social structure were used to construct a stage-structured matrix model and estimate the average age at death (life expectancy) of various classes of individuals. Based on this model, it is estimated that the

P. M. Buston; M. B. Garca

2007-01-01

203

Mechanisms of age-related decline in memory search across the adult life span.  

PubMed

Three alternative mechanisms for age-related decline in memory search have been proposed, which result from either reduced processing speed (global slowing hypothesis), overpersistence on categories (cluster-switching hypothesis), or the inability to maintain focus on local cues related to a decline in working memory (cue-maintenance hypothesis). We investigated these 3 hypotheses by formally modeling the semantic recall patterns of 185 adults between 27 to 99 years of age in the animal fluency task (Thurstone, 1938). The results indicate that people switch between global frequency-based retrieval cues and local item-based retrieval cues to navigate their semantic memory. Contrary to the global slowing hypothesis that predicts no qualitative differences in dynamic search processes and the cluster-switching hypothesis that predicts reduced switching between retrieval cues, the results indicate that as people age, they tend to switch more often between local and global cues per item recalled, supporting the cue-maintenance hypothesis. Additional support for the cue-maintenance hypothesis is provided by a negative correlation between switching and digit span scores and between switching and total items recalled, which suggests that cognitive control may be involved in cue maintenance and the effective search of memory. Overall, the results are consistent with age-related decline in memory search being a consequence of reduced cognitive control, consistent with models suggesting that working memory is related to goal perseveration and the ability to inhibit distracting information. PMID:23586941

Hills, Thomas T; Mata, Rui; Wilke, Andreas; Samanez-Larkin, Gregory R

2013-12-01

204

New strategies to prolong the in vivo life span of iron-based contrast agents for MRI.  

PubMed

Superparamagnetic iron oxide (SPIO) and ultra small superparamagnetic iron oxide (USPIO) nanoparticles have been developed as magnetic resonance imaging (MRI) contrast agents. Iron oxide nanoparticles, that become superparamagnetic if the core particle diameter is ~ 30 nm or less, present R1 and R2 relaxivities which are much higher than those of conventional paramagnetic gadolinium chelates. Generally, these magnetic particles are coated with biocompatible polymers that prevent the agglomeration of the colloidal suspension and improve their blood distribution profile. In spite of their potential as MRI blood contrast agents, the biomedical application of iron oxide nanoparticles is still limited because of their intravascular half-life of only few hours; such nanoparticles are rapidly cleared from the bloodstream by macrophages of the reticulo-endothelial system (RES). To increase the life span of these MRI contrast agents in the bloodstream we proposed the encapsulation of SPIO nanoparticles in red blood cells (RBCs) through the transient opening of cell membrane pores. We have recently reported results obtained by applying our loading procedure to several SPIO nanoparticles with different chemical physical characteristics such as size and coating agent. In the current investigation we showed that the life span of iron-based contrast agents in the mice bloodstream was prolonged to 12 days after the intravenous injection of murine SPIO-loaded RBCs. Furthermore, we developed an animal model that implicates the pretreatment of animals with clodronate to induce a transient suppression of tissue macrophages, followed by the injection of human SPIO-loaded RBCs which make it possible to encapsulate nanoparticle concentrations (5.3-16.7 mM Fe) higher than murine SPIO-loaded RBCs (1.4-3.55 mM Fe). The data showed that, when human RBCs are used as more capable SPIO nanoparticle containers combined with a depletion of tissue macrophages, Fe concentration in animal blood is 2-3 times higher than iron concentration obtained by the use of murine SPIO-loaded RBCs. PMID:24223101

Antonelli, Antonella; Sfara, Carla; Battistelli, Serafina; Canonico, Barbara; Arcangeletti, Marcella; Manuali, Elisabetta; Salamida, Sonia; Papa, Stefano; Magnani, Mauro

2013-01-01

205

The Best Time to Acquire New Skills: Age-related Differences in Implicit Sequence Learning across Human Life Span  

PubMed Central

Implicit skill learning underlies obtaining not only motor, but also cognitive and social skills through the life of an individual. Yet, the ontogenetic changes in humans implicit learning abilities have not yet been characterized, and, thus, their role in acquiring new knowledge efficiently during development is unknown. We investigated such learning across the life span, between 485 years of age with an implicit probabilistic sequence learning task, and we found that the difference in implicitly learning high vs. low probability events - measured by raw reaction time (RT) - exhibited a rapid decrement around age of 12. Accuracy and z-transformed data showed partially different developmental curves suggesting a re-evaluation of analysis methods in developmental research. The decrement in raw RT differences supports an extension of the traditional 2-stage lifespan skill acquisition model: in addition to a decline above the age 60 reported in earlier studies, sensitivity to raw probabilities and, therefore, acquiring new skills is significantly more effective until early adolescence than later in life. These results suggest that due to developmental changes in early adolescence, implicit skill learning processes undergo a marked shift in weighting raw probabilities vs. more complex interpretations of events, which, with appropriate timing, prove to be an optimal strategy for human skill learning. PMID:22709399

Janacsek, K.; Fiser, J.; Nemeth, D.

2012-01-01

206

Sickle Cell Disease: An Opportunity for Palliative Care across the Life Span  

PubMed Central

Sickle cell disease is a chronic illness that impacts patients physically and emotionally and can do so at an early age. An ecological model of palliative care that involves improved communication among the health care team, patients, and their families can be beneficial. Open and honest communication regarding advance care planning, disease management, relief of pain and other symptoms, and bereavement and grief are all important for the patient, family, and health care team. Given the multiple acute and chronic complications of sickle cell disease, an approach to care that is holistic and comprehensive may help to improve a patients biological function and the perceived health, functional status, and quality of life of the patient and family. PMID:20804884

Johnson, Bonnye; Mack, A. Kyle; Labotka, Richard; Molokie, Robert E.

2010-01-01

207

A transdisciplinary perspective of chronic stress in relation to psychopathology throughout life span development.  

PubMed

The allostatic load (AL) model represents an interdisciplinary approach to comprehensively conceptualize and quantify chronic stress in relation to pathologies throughout the life cycle. This article first reviews the AL model, followed by interactions among early adversity, genetics, environmental toxins, as well as distinctions among sex, gender, and sex hormones as integral antecedents of AL. We next explore perspectives on severe mental illness, dementia, and caregiving as unique human models of AL that merit future investigations in the field of developmental psychopathology. A complimenting transdisciplinary perspective is applied throughout, whereby we argue that the AL model goes beyond traditional stress-disease theories toward the advancement of person-centered research and practice that promote not only physical health but also mental health. PMID:21756430

Juster, Robert-Paul; Bizik, Gustav; Picard, Martin; Arsenault-Lapierre, Genevieve; Sindi, Shireen; Trepanier, Lyane; Marin, Marie-France; Wan, Nathalie; Sekerovic, Zoran; Lord, Catherine; Fiocco, Alexandra J; Plusquellec, Pierrich; McEwen, Bruce S; Lupien, Sonia J

2011-08-01

208

Carotenoids and carotenogenic genes in Podospora anserina: engineering of the carotenoid composition extends the life span of the mycelium.  

PubMed

Carotenoids have been identified in the fungus Podospora anserina and a parallel pathway to neurosporene and beta-carotene was established. Three genes for the beta-carotene branch have been cloned and their function elucidated. They correspond to the al-1, al-2 and al-3 genes from Neurospora crassa. They were individually and in combinations over-expressed in P. anserina in order to modify the carotenoid composition qualitatively and quantitatively. In the resulting transformants, carotenoid synthesis was up to eightfold increased and several intermediates of the pathway together with special cyclic carotenoids, beta-zeacarotene and 7,8-dihydro-beta-carotene, accumulated. All transformants with an over-expressed al-2 gene (encoding a phytoene synthase and a lycopene cyclase) displayed up to 31% prolonged life span. PMID:19277665

Strobel, Ingmar; Breitenbach, Jrgen; Scheckhuber, Christian Q; Osiewacz, Heinz D; Sandmann, Gerhard

2009-04-01

209

Metabolism, body size and life span: a case study in evolutionarily divergent populations of the garter snake (Thamnophis elegans).  

PubMed

We present a case study of metabolism, life history and aging in the western terrestrial garter snake (Thamnophis elegans). Early research in the field supported the rate-of-living hypothesis as an explanation of aging, which was based on an apparent negative relationship between mass-specific metabolic rate and lifespan in endotherms. This hypothesis in its original form has not withstood additional tests and comparisons between the two main lineages of endotherms-birds and mammals, but there is still much to be discovered of the causative links among rate of oxygen consumption, physiology and life history, particularly in ectothermic reptiles. We present data that show adult short-lived snakes, from naturally occurring ecotypes of garter snakes, have higher mass-specific resting metabolic rates at any given body mass (metabolic intensity) across a series of normal activity temperatures (15-32C). The short-lived ecotype in this geographic region reaches a larger body size, and has life-history traits that place it at the fast end of a pace-of-life continuum (fast growth, early maturation, high reproductive output) relative to individuals of the small-bodied long-lived ecotype. The difference between ecotypes in metabolic intensity, even after acclimation to identical conditions, may reflect evolutionary divergence and genetic differences between ecotypes. The difference in metabolic intensity is not, however, present at birth, so an alternative is that developmental environment may permanently influence metabolic rate and life history. Such developmental canalization could lead to altered gene expression via environmental influences on the epigenome and result in altered metabolic trajectories in the snakes' natural habitats. PMID:21558247

Bronikowski, Anne; Vleck, David

2010-11-01

210

ATM-dependent phosphorylation of SNEVhPrp19/hPso4 is involved in extending cellular life span and suppression of apoptosis.  

PubMed

Defective DNA repair is widely acknowledged to negatively impact on healthy aging, since mutations in DNA repair factors lead to accelerated and premature aging. However, the opposite, namely if improved DNA repair will also increase the life or health span is less clear, and only few studies have tested if overexpression of DNA repair factors modulates life and health span in cells or organisms. Recently, we identified and characterized SNEVhPrp19/hPso4, a protein that plays a role in DNA repair and pre-mRNA splicing, and observed a doubling of the replicative life span upon ectopic overexpression, accompanied by lower basal DNA damage and apoptosis levels as well as an increased resistance to oxidative stress. Here we find that SNEVhPrp19/hPso4 is phosphorylated at S149 in an ataxia telangiectasia mutated protein (ATM)-dependent manner in response to oxidative stress and DNA double strand break inducing agents. By overexpressing wild-type SNEVhPrp19/hPso4 and a phosphorylation-deficient point-mutant, we found that S149 phosphorylation is necessary for mediating the resistance to apoptosis upon oxidative stress and is partially necessary for elongating the cellular life span. Therefore, ATM dependent phosphorylation of SNEVhPrp19/hPso4 upon DNA damage or oxidative stress might represent a novel axis capable of modulating cellular life span. PMID:22529335

Dellago, Hanna; Khan, Abdulhameed; Nussbacher, Monika; Gstraunthaler, Anna; Lmmermann, Ingo; Schosserer, Markus; Mck, Christoph; Anrather, Dorothea; Scheffold, Annika; Ammerer, Gustav; Jansen-Drr, Pidder; Rudolph, Karl Lenhard; Voglauer-Grillari, Regina; Grillari, Johannes

2012-04-01

211

Feeding into old age: long-term effects of dietary fatty acid supplementation on tissue composition and life span in mice  

PubMed Central

Smaller mammals, such as mice, possess tissues containing more polyunsaturated fatty acids (PUFAs) than larger mammals, while at the same time live shorter lives. These relationships have been combined in the membrane pacemaker hypothesis of aging. It suggests that membrane PUFA content might determine an animals life span. PUFAs in general and certain long-chain PUFAs in particular, are highly prone to lipid peroxidation which brings about a high rate of reactive oxygen species (ROS) production. We hypothesized that dietary supplementation of either n-3 or n-6 PUFAs might affect (1) membrane phospholipid composition of heart and liver tissues and (2) life span of the animals due to the altered membrane composition, and subsequent effects on lipid peroxidation. Therefore, we kept female laboratory mice from the C57BL/6 strain on three diets (n-3 PUFA rich, n-6 PUFA rich, control) and assessed body weights, life span, heart, and liver phospholipid composition after the animals had died. We found that while membrane phospholipid composition clearly differed between feeding groups, life span was not directly affected. However, we were able to observe a positive correlation between monounsaturated fatty acids in cardiac muscle and life span. PMID:20981551

Ruf, Thomas

2010-01-01

212

Reproductive isolation following reintroduction of Chinook salmon with alternative life histories  

Microsoft Academic Search

We evaluated reproductive isolation of Chinook salmon (Oncorhynchus tshawytscha) life history types that have been reintroduced to northern Idaho, USA. Analysis of 1003 samples at six microsatellite loci\\u000a revealed strong reproductive isolation between ocean- and stream-type Chinook salmon (fall and summer spawn timing, respectively)\\u000a within the Clearwater River sub-basin (F\\u000a ST=0.148, P<0.00001). Very little evidence for gene flow among the

Shawn R. Narum; William D. Arnsberg; Andre J. Talbot; Madison S. Powell

2007-01-01

213

Implications of Extreme Life Span in Clonal Organisms: Millenary Clones in Meadows of the Threatened Seagrass Posidonia oceanica  

PubMed Central

The maximum size and age that clonal organisms can reach remains poorly known, although we do know that the largest natural clones can extend over hundreds or thousands of metres and potentially live for centuries. We made a review of findings to date, which reveal that the maximum clone age and size estimates reported in the literature are typically limited by the scale of sampling, and may grossly underestimate the maximum age and size of clonal organisms. A case study presented here shows the occurrence of clones of slow-growing marine angiosperm Posidonia oceanica at spatial scales ranging from metres to hundreds of kilometres, using microsatellites on 1544 sampling units from a total of 40 locations across the Mediterranean Sea. This analysis revealed the presence, with a prevalence of 3.5 to 8.9%, of very large clones spreading over one to several (up to 15) kilometres at the different locations. Using estimates from field studies and models of the clonal growth of P. oceanica, we estimated these large clones to be hundreds to thousands of years old, suggesting the evolution of general purpose genotypes with large phenotypic plasticity in this species. These results, obtained combining genetics, demography and model-based calculations, question present knowledge and understanding of the spreading capacity and life span of plant clones. These findings call for further research on these life history traits associated with clonality, considering their possible ecological and evolutionary implications. PMID:22312426

Arnaud-Haond, Sophie; Duarte, Carlos M.; Diaz-Almela, Elena; Marb, Nria; Sintes, Tomas; Serro, Ester A.

2012-01-01

214

Change of Sex Gaps in Total and Cause-Specific Mortality Over the Life Span in the United States  

PubMed Central

PURPOSE Previous research has led to the expectation that the gap in mortality between sexes narrows in older ages as sex differences in fecundity decrease. However, the patterns and explanations of variations in sex disparities in mortality across the life span and underlying causes of death are not well understood. We conducted a population-based study to further test this hypothesis. METHODS By using a nationally representative sample of adults (N = 25,254) with mortality follow-ups for 18 years, we modeled age variations in sex differences in risks of mortality from leading causes of death. RESULTS Male excesses in mortality decrease at older ages significantly for some but not all causes. Differential exposures to social, physiological, and morbidity risk factors account for the late life reductions of the sex mortality gaps completely in circulatory diseases, partially or minimally in the other causes of death. Social status and relationship are more important risk factors for mortality in younger ages, health behaviors are significant for all ages, and physiological dysregulation is more predictive of mortality in older ages. CONCLUSIONS Sex differences in the risk of mortality have strong age variations and are cause specific. Additional studies of age acceleration of cancer mortality risk are needed. PMID:22100543

YANG, YANG; KOZLOSKI, MICHAEL

2012-01-01

215

Grade Span.  

ERIC Educational Resources Information Center

This issue reviews grade span, or grade configuration. Catherine Paglin and Jennifer Fager's "Grade Configuration: Who Goes Where?" provides an overview of issues and concerns related to grade spans and supplies profiles of eight Northwest schools with varying grade spans. David F. Wihry, Theodore Coladarci, and Curtis Meadow's "Grade Span and

Renchler, Ron

2000-01-01

216

Early Reproductive Experiences in Females Make Differences in Cognitive Function Later in Life  

PubMed Central

Women experience dramatic changes in hormones, mood and cognition through different periods of their reproductive lives, particularly during pregnancy and giving birth. While limited human studies of early pregnancy and motherhood showed alteration of cognitive function in later life, research conducted on rodents showed a persistent improvement of learning and memory performance in females with history of giving birth (primiparous or multiparous) compared to virgin controls (nulliparous). In this mini review, we will focus on the effect of early motherhood on cognitive function later in life, which would provide insight on how reproductive experiences influence womens health during ageing. PMID:23271317

Li, Rena; Cui, Jie; Jothishankar, Balaji; Shen, Juliet; He, Ping; Shen, Yong

2012-01-01

217

The evolution of life histories in garter snakes: Reproduction, aging, and the physiology of trade-offs  

Microsoft Academic Search

Life-history theory predicts that optimal life histories are shaped by trade-offs among traits expressed in different evolutionary and ecological contexts. Fast growth and high reproduction are predicted to trade off with lifespan, with the result that \\

Amanda M. Sparkman

2009-01-01

218

Histone H1 Is Dispensable for Methylation-Associated Gene Silencing in Ascobolus immersus and Essential for Long Life Span  

PubMed Central

A gene encoding a protein that shows sequence similarity with the histone H1 family only was cloned in Ascobolus immersus. The deduced peptide sequence presents the characteristic three-domain structure of metazoan linker histones, with a central globular region, an N-terminal tail, and a long positively charged C-terminal tail. By constructing an artificial duplication of this gene, named H1, it was possible to methylate and silence it by the MIP (methylation induced premeiotically) process. This resulted in the complete loss of the Ascobolus H1 histone. Mutant strains lacking H1 displayed normal methylation-associated gene silencing, underwent MIP, and showed the same methylation-associated chromatin modifications as did wild-type strains. However, they displayed an increased accessibility of micrococcal nuclease to chromatin, whether DNA was methylated or not, and exhibited a hypermethylation of the methylated genome compartment. These features are taken to imply that Ascobolus H1 histone is a ubiquitous component of chromatin which plays no role in methylation-associated gene silencing. Mutant strains lacking histone H1 reproduced normally through sexual crosses and displayed normal early vegetative growth. However, between 6 and 13 days after germination, they abruptly and consistently stopped growing, indicating that Ascobolus H1 histone is necessary for long life span. This constitutes the first observation of a physiologically important phenotype associated with the loss of H1. PMID:10594009

Barra, Jose L.; Rhounim, Lala; Rossignol, Jean-Luc; Faugeron, Godeleine

2000-01-01

219

Low fatty acid unsaturation: a mechanism for lowered lipoperoxidative modification of tissue proteins in mammalian species with long life spans.  

PubMed

Carbonyl compounds generated by the nonenzymatic oxidation of polyunsaturated fatty acids react with nucleophilic groups in proteins, leading to their modification. It has not been tested whether fatty acid unsaturation is related to steady-state levels of lipoxidation-derived protein modification in vivo. A low fatty acid unsaturation, hence a low protein lipoxidation, in tissues of longevous animals would be consistent with the free radical theory of aging, because membrane lipids increase their sensitivity to oxidative damage as a function of their degree of unsaturation. To evaluate the relationship between fatty acid composition, protein lipoxidation, and maximum life span (MLSP), we analyzed liver fatty acids and proteins from seven mammalian species, ranging in MLSP from 3.5 to 46 years. The results show that the peroxidizability index of fatty acids and the sensitivity to in vitro lipid peroxidation are negatively correlated with the MLSP. Based on gas chromatography and mass spectroscopy analyses, liver proteins of all these species contain malondialdehyde-lysine and Nepsilon-carboxymethyllysine adducts, two biomarkers of protein lipoxidation. The steady-state levels of malondialdehyde-lysine and Nepsilon-carboxymethyl lysine are directly related to the peroxidizability index and inversely related to the MLSP. We propose that a low degree of fatty acid unsaturation may have been selected in longevous mammals to protect their tissue lipids and proteins against oxidative damage while maintaining an appropriate environment for membrane function. PMID:10843345

Pamplona, R; Portero-Otn, M; Riba, D; Requena, J R; Thorpe, S R; Lpez-Torres, M; Barja, G

2000-06-01

220

Low-Income Women's Navigation of Childbearing Norms Throughout the Reproductive Life Course.  

PubMed

Shifts in family structure have affected age norms about both teenage childbearing and reproductive sterilization, but we lack research examining how childbearing norms are connected across the reproductive life course. Drawing on interviews from 40 low-income women in Colorado, we explored linkages between early childbearing and the desire for early sterilization. Specifically, we examined two narratives women use to negotiate competing norms throughout the reproductive life course. The low-income women in our study characterized their teenage childbearing experiences negatively and justified them using a "young and dumb" narrative. Women also asserted that reversible contraceptives do not work for them, using a "hyper-fertility" narrative to explain both their early childbearing and their desire for early sterilization. Our results illustrate the influence of mainstream social norms about childbearing timing on low-income women's lives and provide evidence of how women use narratives to explain and justify their violation of childbearing norms. PMID:25185163

James-Hawkins, Laurie; Sennott, Christie

2015-01-01

221

Expression of multiple copies of mitochondrially targeted catalase or genomic Mn superoxide dismutase transgenes does not extend the life span of Drosophila melanogaster  

Microsoft Academic Search

The simultaneous overexpression of multiple copies of Mn superoxide dismutase (SOD) and ectopic catalase (mtCat) transgenes in the mitochondria of the fruit fly, Drosophila melanogaster, was shown previously to diminish the life span. The hypothesis tested in this study was that this effect was due primarily to the presence of one or the other transgene. An alternative hypothesis was that

Robin J. Mockett; Barbara H. Sohal; Rajindar S. Sohal

2010-01-01

222

Reproductive conflict and the separation of reproductive generations in humans  

PubMed Central

An enduring puzzle of human life history is why women cease reproduction midway through life. Selection can favor postreproductive survival because older females can help their offspring to reproduce. But the kin-selected fitness gains of helping appear insufficient to outweigh the potential benefits of continued reproduction. Why then do women cease reproduction in the first place? Here, we suggest that early reproductive cessation in humans is the outcome of reproductive competition between generations, and we present a simple candidate model of how this competition will be resolved. We show that among primates exhibiting a postreproductive life span, humans exhibit an extraordinarily low degree of reproductive overlap between generations. The rapid senescence of the human female reproductive system coincides with the age at which, in natural fertility populations, women are expected to encounter reproductive competition from breeding females of the next generation. Several lines of evidence suggest that in ancestral hominids, this younger generation typically comprised immigrant females. In these circumstances, relatedness asymmetries within families are predicted to give younger females a decisive advantage in reproductive conflict with older females. A model incorporating both the costs of reproductive competition and the benefits of grandmothering can account for the timing of reproductive cessation in humans and so offers an improved understanding of the evolution of menopause. PMID:18378891

Cant, Michael A.; Johnstone, Rufus A.

2008-01-01

223

A costbenefit analysis of acclimation to low irradiance in tropical rainforest tree seedlings: leaf life span and payback time for leaf deployment  

PubMed Central

The maintenance in the long run of a positive carbon balance under very low irradiance is a prerequisite for survival of tree seedlings below the canopy or in small gaps in a tropical rainforest. To provide a quantitative basis for this assumption, experiments were carried out to determine whether construction cost (CC) and payback time for leaves and support structures, as well as leaf life span (i) differ among species and (ii) display an irradiance-elicited plasticity. Experiments were also conducted to determine whether leaf life span correlates to CC and payback time and is close to the optimal longevity derived from an optimization model. Saplings from 13 tropical tree species were grown under three levels of irradiance. Specific-CC was computed, as well as CC scaled to leaf area at the metamer level. Photosynthesis was recorded over the leaf life span. Payback time was derived from CC and a simple photosynthesis model. Specific-CC displayed only little interspecific variability and irradiance-elicited plasticity, in contrast to CC scaled to leaf area. Leaf life span ranged from 4 months to >26 months among species, and was longest in seedlings grown under lowest irradiance. It was always much longer than payback time, even under the lowest irradiance. Leaves were shed when their photosynthesis had reached very low values, in contrast to what was predicted by an optimality model. The species ranking for the different traits was stable across irradiance treatments. The two pioneer species always displayed the smallest CC, leaf life span, and payback time. All species displayed a similar large irradiance-elicited plasticity. PMID:21511904

Coste, Sabrina; Roggy, Jean-Christophe; Schimann, Heidy; Epron, Daniel; Dreyer, Erwin

2011-01-01

224

Radiation exposure and the risk of mortality from noncancer respiratory diseases in the life span study, 1950-2005.  

PubMed

An apparent association between radiation exposure and noncancer respiratory diseases (NCRD) in the Life Span Study (LSS) of atomic bomb survivors has been reported, but the biological validity of that observation is uncertain. This study investigated the possibility of radiation causation of noncancer respiratory diseases in detail by examining subtypes of noncancer respiratory diseases, temporal associations, and the potential for misdiagnosis and other confounding factors. A total of 5,515 NCRD diagnoses listed as the underlying cause of death on the death certificate were observed among the 86,611 LSS subjects with estimated weighted absorbed lung doses. Radiation dose-response analyses were conducted using Cox proportional hazard regression for pneumonia/influenza, other acute respiratory infections, chronic obstructive pulmonary disease and asthma. The linear excess relative risks (ERR) per gray (Gy) were 0.17 (95% CI 0.08, 0.27) for all NCRD and 0.20 (CI 0.09, 0.34) for pneumonia/influenza, which accounted for 63% of noncancer respiratory disease deaths. Adjustments for lifestyle and sociodemographic variations had almost no impact on the risk estimates. However, adjustments for indications of cancer and/or cardiovascular disease decreased the risk estimates, with ERR for total noncancer respiratory diseases declined by 35% from 0.17 to 0.11. Although it was impossible to fully adjust for the misdiagnosis of other diseases as noncancer respiratory diseases deaths in this study because of limitations of available data, nevertheless, the associations were reduced or eliminated by the adjustment that could be made. This helps demonstrates that the association between noncancer respiratory diseases and radiation exposure in previous reports could be in part be attributed to coincident cancer and/or cardiovascular diseases. PMID:24148011

Pham, Truong-Minh; Sakata, Ritsu; Grant, Eric J; Shimizu, Yukiko; Furukawa, Kyoji; Takahashi, Ikuno; Sugiyama, Hiromi; Kasagi, Fumiyoshi; Soda, Midori; Suyama, Akihiko; Shore, Roy E; Ozasa, Kotaro

2013-11-01

225

Body size, growth and life span: implications for the polewards range shift of Octopus tetricus in south-eastern Australia.  

PubMed

Understanding the response of any species to climate change can be challenging. However, in short-lived species the faster turnover of generations may facilitate the examination of responses associated with longer-term environmental change. Octopus tetricus, a commercially important species, has undergone a recent polewards range shift in the coastal waters of south-eastern Australia, thought to be associated with the southerly extension of the warm East Australian Current. At the cooler temperatures of a polewards distribution limit, growth of a species could be slower, potentially leading to a bigger body size and resulting in a slower population turnover, affecting population viability at the extreme of the distribution. Growth rates, body size, and life span of O. tetricus were examined at the leading edge of a polewards range shift in Tasmanian waters (40S and 147E) throughout 2011. Octopus tetricus had a relatively small body size and short lifespan of approximately 11 months that, despite cooler temperatures, would allow a high rate of population turnover and may facilitate the population increase necessary for successful establishment in the new extended area of the range. Temperature, food availability and gender appear to influence growth rate. Individuals that hatched during cooler and more productive conditions, but grew during warming conditions, exhibited faster growth rates and reached smaller body sizes than individuals that hatched into warmer waters but grew during cooling conditions. This study suggests that fast growth, small body size and associated rapid population turnover may facilitate the range shift of O. tetricus into Tasmanian waters. PMID:25090250

Ramos, Jorge E; Pecl, Gretta T; Moltschaniwskyj, Natalie A; Strugnell, Jan M; Len, Rafael I; Semmens, Jayson M

2014-01-01

226

Effect of repetitive acute cold exposures during the last phase of broiler embryogenesis on cold resistance through the life span.  

PubMed

The time just before hatch is critical, because the embryo shifts toward internal and external pipping. This study aimed to determine the beneficial effect of repeated acute reductions of the incubation temperature during the last phase of broiler embryogenesis on posthatch cold tolerance and on the development of ascites syndrome. Fertile eggs were incubated at 37.8 degrees C and 56% RH. At 18 and 19 d of incubation, 3 treatments were conducted, comprising 2 or 3 exposures to 15 degrees C for 30 or 60 min each. During these cold exposures, egg temperature was measured by infrared thermography to determine sensible heat loss from the eggs. At hatch, BW and body temperature were measured. At 3 and 14 d of age, chicks were challenged by cold exposure to 10 degrees C for 3 h. From 14 d of age onward, three-quarters of the chicks were raised under ascites-inducing conditions (AIC) and the others were raised under regular conditions. The sensible heat loss from the eggs was 512 +/- 66 cal and 718 +/- 126 cal for 30 and 60 min of cold exposure, respectively. No effect of treatment on hatchability was observed, but body temperature and BW were greater to significantly greater in the treated chicks. Cold challenges at 3 and 14 d of age revealed a relative thermoregulatory advantage of embryos exposed to cold for 60 min. Under AIC, fewer treated chickens than controls developed ascites. At 38 d of age, BW and relative breast muscle weight were numerically to significantly greater in the treated chicks than in the control chicks when both were raised under regular conditions, whereas no differences were observed among the chicks raised under AIC. Repeated brief acute cold exposures during the last phase of embryogenesis appeared to improve the ability of growing broilers to withstand low ambient temperatures during their life span. Moreover, chickens treated during embryogenesis improved their performance under regular growth conditions. PMID:19211536

Shinder, D; Rusal, M; Giloh, M; Yahav, S

2009-03-01

227

Evaluation of platelet thromboxane radioimmunoassay method to measure platelet life-span: Comparison with /sup 111/indium-platelet method  

SciTech Connect

The platelet activation during radiolabeling in vitro with Cr-51 and In-111 may affect the platelet life-span (PLS) in vivo. A new RIA method to measure PLS is being evaluated. Aspirin inhibits platelet thromboxane (TxA/sub 2/) by acetylating cyclooxygenase. The time required for the TxA/sub 2/ levels to return towards control values depends on the rate of new platelets entering circulation and is a measure of PLS. A single dose of aspirin (150mg) was given to 5 normal human subjects. Blood samples were collected for 2 days before aspirin and daily for 10 days. TxA/sub 2/ production in response to endogenous thrombin was studied by allowing 1 ml blood sample to clot at 37/sup 0/C for 90 min. Serum TxB/sub 2/ (stable breakdown product of Tx-A/sub 2/) levels determined by RIA technique. The plot of TxB/sub 2/ levels (% control) against time showed a gradual increase. The PLS calculated by linear regression analysis assuming a 2-day lag period before cyclooxygenase recovery is 9.7 +- 2.37. In the same 5 subjects, platelets from a 50ml blood sample were labeled with /sup 111/In-tropolone in 2 ml autologous plasma. Starting at 1 hr after injection of labeled platelets, 10 blood samples were obtained over a 8 day period. The PLS calculated based on a linear regression analysis is 10.2 +. 1.4. The PLS measured from the rate of platelet disappearance from circulation and the rate of platelet regeneration into circulation are quite comparable in normal subjects. TxA/sub 2/ regeneration RIA may provide a method to measure PLS without administering radioactivity to patient.

Vallabhajosula, S.; Machac, J.; Badimon, L.; Lipszyc, H.; Goldsmith, S.J.; Fuster, V.

1985-05-01

228

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

PubMed

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. PMID:24089339

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

2013-11-22

229

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

PubMed Central

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. PMID:24089339

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

2013-01-01

230

The adaptive value of morphological, behavioural and life-history traits in reproductive female wolves.  

PubMed

Reproduction in social organisms is shaped by numerous morphological, behavioural and life-history traits such as body size, cooperative breeding and age of reproduction, respectively. Little is known, however, about the relative influence of these different types of traits on reproduction, particularly in the context of environmental conditions that determine their adaptive value. Here, we use 14 years of data from a long-term study of wolves (Canis lupus) in Yellowstone National Park, USA, to evaluate the relative effects of different traits and ecological factors on the reproductive performance (litter size and survival) of breeding females. At the individual level, litter size and survival improved with body mass and declined with age (c. 4-5 years). Grey-coloured females had more surviving pups than black females, which likely contributed to the maintenance of coat colour polymorphism in this system. The effect of pack size on reproductive performance was nonlinear as litter size peaked at eight wolves and then declined, and litter survival increased rapidly up to three wolves, beyond which it increased more gradually. At the population level, litter size and survival decreased with increasing wolf population size and canine distemper outbreaks. The relative influence of these different-level factors on wolf reproductive success followed individual > group > population. Body mass was the primary determinant of litter size, followed by pack size and population size. Body mass was also the main driver of litter survival, followed by pack size and disease. Reproductive gains because of larger body size and cooperative breeding may mitigate reproductive losses because of negative density dependence and disease. These findings highlight the adaptive value of large body size and sociality in promoting individual fitness in stochastic and competitive environments. PMID:23043440

Stahler, Daniel R; MacNulty, Daniel R; Wayne, Robert K; vonHoldt, Bridgett; Smith, Douglas W

2013-01-01

231

Care and the self: biotechnology, reproduction, and the good life  

PubMed Central

This paper explores a novel philosophy of ethical care in the face of burgeoning biomedical technologies. I respond to a serious challenge facing traditional bioethics with its roots in analytic philosophy. The hallmarks of these traditional approaches are reason and autonomy, founded on a belief in the liberal humanist subject. In recent years, however, there have been mounting challenges to this view of human subjectivity, emerging from poststructuralist critiques, such as Michel Foucault's, but increasingly also as a result of advances in biotechnology itself. In the face of these developments, I argue that the theoretical relevance and practical application of mainstream bioethics is increasingly under strain. Traditionalists will undoubtedly resist. Together, professional philosopher-bioethicists, public health policymakers, and the global commercial healthcare industry tend to respond conservatively by shoring up the liberal humanist subject as the foundation for medical ethics and consumer decision-making, appealing to the familiar tropes of reason, autonomy, and freedom. I argue for a different approach to bioethics, and work towards a new way to conceive of ethical relations in healthcare one that does not presume a sovereign subject as the basis of dignity, personhood or democracy. Instead, I am critical of the narrow instantiations of reason, autonomy, and freedom, which, more recently, have been co-opted by a troubling neo-liberal politics of the self. Thus, I am critical of current trends in medical ethics, often running in tandem with corporate-governmental models of efficiency, accountability, and so-called evidence-based best practices. As an example of such market-driven conceptions of subjectivity, I discuss the paradigm of "self-care." Self-care shores up the traditional view of the self as a free agent. In this sense, self-care is looked upon favourably by mainstream bioethics in its focus on autonomy, while healthcare policy endorses this model for ideological and economic reasons. To contrast this, I propose a different model of care together with a different model of selfhood. Here I develop and apply Foucault's late work on the "care of the self." In this understanding of "care," I suggest that we might work towards an ethical self that is more commensurable both with recent theoretical views on subjectivity and more pressingly with the challenges of emergent biotechnologies. I end this paper with a discussion on ethical parenthood, which offers a practical reading of the "care of the self" in relation to new reproductive technologies (NRTs). PMID:17480234

Murray, Stuart J

2007-01-01

232

Environmental Contingency in Life History Strategies: The Influence of Mortality and Socioeconomic Status on Reproductive Timing  

PubMed Central

Why do some people have children early, whereas others delay reproduction? By considering the trade-offs between using ones resources for reproduction versus other tasks, the evolutionary framework of life history theory predicts that reproductive timing should be influenced by mortality and resource scarcity. A series of experiments examined how mortality cues influenced the desire to have children sooner rather than later. The effects of mortality depended critically on whether people grew up in a relatively resource-scarce or resource-plentiful environment. For individuals growing up relatively poor, mortality cues produced a desire to reproduce soonerto want children now, even at the cost of furthering ones education or career. Conversely, for individuals growing up relatively wealthy, mortality cues produced a desire to delay reproductionto further ones education or career before starting a family. Overall, mortality cues appear to shift individuals into different life history strategies as a function of childhood socioeconomic status, suggesting important implications for how environmental factors can influence fertility and family size. PMID:20873933

Griskevicius, Vladas; Delton, Andrew W.; Robertson, Theresa E.; Tybur, Joshua M.

2013-01-01

233

Hypothalamic neural systems controlling the female reproductive life cycle: Gonadotropin-releasing hormone, glutamate, and GABA  

PubMed Central

The hypothalamic-pituitary-gonadal (HPG) axis undergoes a number of changes throughout the reproductive life cycle that are responsible for the development, puberty, adulthood, and senescence of reproductive systems. This natural progression is dictated by the neural network controlling the hypothalamus including the cells that synthesize and release gonadotropin-releasing hormone (GnRH) and their regulatory neurotransmitters. Glutamate and GABA are the primary excitatory and inhibitory neurotransmitters in the central nervous system, and as such contribute a great deal to modulating this axis throughout the lifetime via their actions on receptors in the hypothalamus, both directly on GnRH neurons as well as indirectly though other hypothalamic neural networks. Interactions among GnRH neurons, glutamate, and GABA, including the regulation of GnRH gene and protein expression, hormone release, and modulation by estrogen, are critical to age-appropriate changes in reproductive function. Here, we present evidence for the modulation of GnRH neurosecretory cells by the balance of glutamate and GABA in the hypothalamus, and the functional consequences of these interactions on reproductive physiology across the life cycle. PMID:19349036

Maffucci, Jacqueline A.; Gore, Andrea C.

2009-01-01

234

nfi-1 affects behavior and life-span in C. elegans but is not essential for DNA replication or survival  

PubMed Central

Background The Nuclear Factor I (one) (NFI) family of transcription/replication factors plays essential roles in mammalian gene expression and development and in adenovirus DNA replication. Because of its role in viral DNA replication NFI has long been suspected to function in host DNA synthesis. Determining the requirement for NFI proteins in mammalian DNA replication is complicated by the presence of 4 NFI genes in mice and humans. Loss of individual NFI genes in mice cause defects in brain, lung and tooth development, but the presence of 4 homologous NFI genes raises the issue of redundant roles for NFI genes in DNA replication. No NFI genes are present in bacteria, fungi or plants. However single NFI genes are present in several simple animals including Drosophila and C. elegans, making it possible to test for a requirement for NFI in multicellular eukaryotic DNA replication and development. Here we assess the functions of the single nfi-1 gene in C. elegans. Results C. elegans NFI protein (CeNFI) binds specifically to the same NFI-binding site recognized by vertebrate NFIs. nfi-1 encodes alternatively-spliced, maternally-inherited transcripts that are expressed at the single cell stage, during embryogenesis, and in adult muscles, neurons and gut cells. Worms lacking nfi-1 survive but have defects in movement, pharyngeal pumping and egg-laying and have a reduced life-span. Expression of the muscle gene Ce titin is decreased in nfi-1 mutant worms. Conclusion NFI gene function is not needed for survival in C. elegans and thus NFI is likely not essential for DNA replication in multi-cellular eukaryotes. The multiple defects in motility, egg-laying, pharyngeal pumping, and reduced lifespan indicate that NFI is important for these processes. Reduction in Ce titin expression could affect muscle function in multiple tissues. The phenotype of nfi-1 null worms indicates that NFI functions in multiple developmental and behavioral systems in C. elegans, likely regulating genes that function in motility, egg-laying, pharyngeal pumping and lifespan maintenance. PMID:16242019

Lazakovitch, Elena; Kalb, John M; Matsumoto, Reiko; Hirono, Keiko; Kohara, Yuji; Gronostajski, Richard M

2005-01-01

235

Relationships of leaf dark respiration to leaf nitrogen, specific leaf area and leaf life-span: a test across biomes and functional groups  

Microsoft Academic Search

Based on prior evidence of coordinated multiple leaf trait scaling, we hypothesized that variation among species in leaf\\u000a dark respiration rate (R\\u000a d) should scale with variation in traits such as leaf nitrogen (N), leaf life-span, specific leaf area (SLA), and net photosynthetic\\u000a capacity (A\\u000a max). However, it is not known whether such scaling, if it exists, is similar among

Peter B. Reich; Michael B. Walters; David S. Ellsworth; James M. Vose; John C. Volin; Charles GreshamWilliam; William D. Bowman

1998-01-01

236

Behavioral reactivity to novelty during youth as a predictive factor of stress-induced corticosterone secretion in the elderlya life-span study in rats  

Microsoft Academic Search

Inter- and intea-individual differences in hypothalamo-pituitary adrenal (HPA) axis activity and behavioral reactivity to novelty between young and old rats were evidenced in this longitudinal life-span study. Higher responders to novelty (HR) had a higher corticosterone secretion which showed a quicker increase with age than did the others (LR); the differences in response to novelty observed in youth were no

F. Dellu; W. Mayo; M. Valle; S. Maccari; P. V. Piazza; M. Le Moal; H. Simon

1996-01-01

237

Genome-Wide Screen in Saccharomyces cerevisiae Identifies Vacuolar Protein Sorting, Autophagy, Biosynthetic, and tRNA Methylation Genes Involved in Life Span Regulation  

Microsoft Academic Search

The study of the chronological life span of Saccharomyces cerevisiae, which measures the survival of populations of non-dividing yeast, has resulted in the identification of homologous genes and pathways that promote aging in organisms ranging from yeast to mammals. Using a competitive genome-wide approach, we performed a screen of a complete set of approximately 4,800 viable deletion mutants to identify

Paola Fabrizio; Shawn Hoon; Mehrnaz Shamalnasab; Abdulaye Galbani; Min Wei; Guri Giaever; Corey Nislow; Valter D. Longo

2010-01-01

238

Genetic parameters for productive life traits and reproductive efficiency traits at 6 years in Nellore cattle  

Microsoft Academic Search

The objective of the present study was to estimate (co)variance components for length of productive life (LPL) and some alternative reproductive traits of 6-year-old Nellore cattle. The data set contained 57,410 records for age at first calving from Nel- lore females and was edited to remove animal records with uncertain paternity and cows with just one piece of calving information.

J. C. C. Balieiro; J. P. Eler; J. B. S. Ferraz; E. C. Mattos; C. C. Balieiro

2008-01-01

239

Effects of radiation and lifestyle factors on risks of urothelial carcinoma in the Life Span Study of atomic bomb survivors.  

PubMed

Among the Life Span Study (LSS) of Atomic-bomb survivors, recent estimates showed that unspecified bladder cancer had high radiation sensitivity with a notably high female-to-male excess relative risk (ERR) per radiation dose ratio and were the only sites for which the ERR did not decrease with attained age. These findings, however, did not consider lifestyle factors, which could potentially confound or modify the risk estimates. This study estimated the radiation risks of the most prevalent subtype of urinary tract cancer, urothelial carcinoma, while accounting for smoking, consumption of fruit, vegetables, alcohol and level of education (a surrogate for socioeconomic status). Eligible study subjects included 105,402 (males = 42,890) LSS members who were cancer-free in 1958 and had estimated radiation doses. Members were censored due to loss of follow-up, incident cancer of another type, death, or the end of calendar year 2001. Surveys (by mail or clinical interview) gathered lifestyle data periodically for 1963-1991. There were 63,827 participants in one or more survey. Five hundred seventy-three incident urothelial carcinoma cases occurred, of which 364 occurred after lifestyle information was available. Analyses were performed using Poisson regression methods. The excess relative risk per weighted gray unit (the gamma component plus 10 times the neutron component, Gy(w)) was 1.00 (95% CI: 0.43-1.78) but the risks were not dependent upon age at exposure or attained age. Lifestyle factors other than smoking were not associated with urothelial carcinoma risk. Neither the magnitude of the radiation ERR estimate (1.00 compared to 0.96), nor the female-to-male (F:M) ERR/Gy(w) ratio (3.2 compared to 3.4) were greatly changed after accounting for all lifestyle factors. A multiplicative model of gender-specific radiation and smoking effects was the most revealing though there was no evidence of significant departures from either the additive or multiplicative joint effect models. Among the LSS cohort members with doses greater than 0.005 Gy(w) (average dose 0.21 Gy(w)), the attributable fraction of urothelial carcinoma due to radiation was 7.1% in males and 19.7% in females. Among current smokers, the attributable fraction of urothelial carcinoma due to smoking was 61% in males and 52% in females. Relative risk estimates of smoking risk were approximately two for smokers compared to nonsmokers. After adjustment for lifestyle factors, gender-specific radiation risks and the F:M ERR/Gy(w), the ratios of excess urothelial carcinoma risk were similar to the estimates without adjusting for lifestyle factors. Smoking was the primary factor responsible for excess urothelial carcinoma in this cohort. These findings led us to conclude that the radiation risk estimates of urothelial carcinoma do not appear to be strongly confounded or modified by smoking, consumption of alcohol, fruits, or vegetables, or level of education. PMID:22631857

Grant, E J; Ozasa, K; Preston, D L; Suyama, A; Shimizu, Y; Sakata, R; Sugiyama, H; Pham, T-M; Cologne, J; Yamada, M; De Roos, A J; Kopecky, K J; Porter, M P; Seixas, N; Davis, S

2012-07-01

240

Life Table Evaluation of Survival and Reproduction of the Aphid, Sitobion avenae, Exposed to Cadmium  

PubMed Central

The effects of cadmium (Cd) on the development, fecundity, and reproduction of the grain aphid, Sitobion avenae Fabricius (Hemiptera: Aphididae) were estimated by constructing a life table of S. avenae exposed to Cd. The concentrations of Cd in the soil were as follows: 0, 10, 20, 40, 80, and 160 mg/kg. The correlation analysis of the Cd concentration in soil and wheat revealed that the amount in the wheat increased with the increase of Cd concentrations in soil. The results indicated that, the latter part of the reproduction period was significantly affected by Cd, according to the curve of the total survival rate (lx). The net reproductive rate (R 0), innate capacity of increase (r), and finite rate of increase (?) of S. avenae all decreased under the stress of Cd, and were lowest at a Cd concentration of 20 mg/kg. Cd also negatively affected fecundity and mx (the number of offspring produced by an individual female). At 20 mg/kg, the decline of them was most obvious. In conclusion, survival and reproduction of S. avenae were inhibited under the treatment of the heavy metal Cd. Sitobion avenae was more sensitive to Cd at concentration of 20 mg/kg compared to the other concentrations. This concentration can be used to examine the mechanisms behind population genetics and biological mutation of S. avenae when exposed to heavy metal. PMID:22958415

Gao, Huan-Huan; Zhao, Hui-Yan; Du, Chao; Deng, Ming-Ming; Du, Er-Xia; Hu, Zu-Qing; Hu, Xiang-Shun

2012-01-01

241

Rapid weight gain after birth predicts life history and reproductive strategy in Filipino males  

PubMed Central

Ecological cues during prenatal and postnatal development may allow organisms to adjust reproductive strategy. The hypothalamic-pituitary-gonadal (HPG) axis is a prime candidate for adaptive plasticity as a result of its critical period of birth to 6 mo (B6M) in humans and the role of testosterone in the development and maintenance of costly sexually dimorphic somatic and behavioral traits. We hypothesized that weight velocity specific to B6M would predict male life history characteristics, including maturational timing, reproductive hormones, adult size, strength, and sexual activity. Data come from 770 Filipino men (age 20.522.5 y) followed since birth, with predictor variables including birth weight and weight velocities calculated at 6-mo intervals during the first 2 y of life. As expected, infants who were breastfed experienced less diarrhea, lived in wealthier households with better hygiene, and grew faster from B6M. Males with rapid B6M growth reached puberty earlier and, as young adults, had higher testosterone levels, were taller, more muscular, and had higher grip strength. They also had sex earlier and were more likely to report having had sex in the past month, resulting in more lifetime sex partners. Relationships between B6M weight gain and physical outcomes were generally not present or weaker in female subjects. We conclude that rapid weight gain specific to the brief postnatal hypothalamic-pituitary-gonadal critical period predicts early maturation and sexual activity, elevated hormone production, and more costly adult somatic characteristics among the male subjects in this sample. These findings provide evidence for early life developmental plasticity in male life history and reproductive strategy in humans. PMID:20837542

Kuzawa, Christopher W.; McDade, Thomas W.; Adair, Linda S.; Lee, Nanette

2010-01-01

242

Outcome of Assisted Reproductive Technology (ART) and Subsequent Self-Reported Life Satisfaction  

PubMed Central

Objective To compare life satisfaction between women with successful or unsuccessful outcome after assisted reproductive treatment (ART) by taking into account the time since the last ART. Design Cohort study. Setting Tertiary hospital. Patients A total of 987 consecutive women who had undergone ART during 19962007 were invited and altogether 505 women participated in the study. Interventions A postal enquiry with a life satisfaction scale. Main Outcome Measure Self-reported life satisfaction in respect to the time since the last ART. Results In general, women who achieved a live birth after ART had a significantly higher life satisfaction than those who had unsuccessful ART, especially when compared in the first three years. The difference disappeared in the time period of 69 years after ART. The unsuccessfully treated women who had a child by some other means before or after the unsuccessful ART had comparable life satisfaction with successfully treated women even earlier. Conclusions Even if unsuccessful ART outcome is associated with subsequent lower level of life satisfaction, it does not seem to threaten the long-term wellbeing. PMID:25393846

Kuivasaari-Pirinen, Paula; Koivumaa-Honkanen, Heli; Hippelinen, Maritta; Raatikainen, Kaisa; Heinonen, Seppo

2014-01-01

243

Individual quality, early-life conditions, and reproductive success in contrasted populations of large herbivores.  

PubMed

Variations among individuals in phenotypic quality and fitness often confound analyses of life-history strategies assessed at the population level. We used detailed long-term data from three populations of large herbivores with generation times ranging from four to nine years to quantify heterogeneity in individual quality among females, and to assess its influence on mean annual reproductive success over the lifetime (MRS). We also determined how environmental conditions in early life shaped individual quality and tested A. Lomnicki's hypothesis that variance in individual quality should increase when environmental conditions deteriorate. Using multivariate analyses (PCA), we identified one (in sheep and deer) or two (in goats) covariations among life-history traits (longevity, success in the last breeding opportunity, adult mass, and social rank) as indexes of individual quality that positively influenced MRS of females. Individual quality was reduced by unfavorable weather, low resource availability, and high population density in the year of birth. Early-life conditions accounted for 35-55% of variation in individual quality. In roe deer, we found greater variance in individual quality for cohorts born under unfavorable conditions as opposed to favorable ones, but the opposite was found in bighorn sheep and mountain goats. Our results demonstrate that heterogeneity in female quality can originate from environmental conditions in early life and can markedly influence the fitness of females in species located at different positions along the slow-fast continuum of life-history strategies. PMID:19694145

Hamel, Sandra; Gaillard, Jean-Michel; Festa-Bianchet, Marco; Ct, Steeve D

2009-07-01

244

The genetic basis of early-life morphological traits and their relation to alternative male reproductive tactics in Atlantic salmon  

E-print Network

variation, particularly at life-cycle stages where selection is known to occur, is required. In many animalThe genetic basis of early-life morphological traits and their relation to alternative male reproductive tactics in Atlantic salmon D. J. PA´ EZ*, M. MORRISSEY , L. BERNATCHEZ* & J. J. DODSON* *Que

Bernatchez, Louis

245

Life span and thymic lymphoma incidence in high- and low-dose-rate irradiated AKR/J mice and commonly expressed genes.  

PubMed

To evaluate the effect of low-dose-rate radiation on cancer incidence, we housed AKR/J mice in a long-term low-dose-rate irradiation facility ((137)Cs, 0.07 cGy/h). We compared the thymic lymphoma incidence and life span with those of mice irradiated at a high dose rate ((137)Cs, 0.8 Gy/min, total dose of 4.5 Gy) and nonirradiated mice. The average life span of the low-dose-rate irradiated mice (243 days) was longer than those of the high-dose-rate irradiated mice (208 days) and nonirradiated mice (230 days) (P = 0.02). The incidence of thymic lymphoma in low-dose-rate irradiated mice was lower than that in nonirradiated mice and high-dose-rate irradiated mice by 10 and 20%, respectively (P < 0.01). Normal-sized thymuses were collected 130 days after irradiation, and whole genome microarray analysis was performed. A total of 17,625 genes were assessed. Up- and down-regulated genes in low-dose-rate irradiated mice were 1.7 and 9 times less frequent than in high-dose-rate irradiated mice. We profiled expressed genes associated with carcinogenesis pathways (DNA repair, DNA damage signaling pathway, cell cycle, cancer pathway finder, p53 signaling pathway, apoptosis and T-cell and B-cell activation). Apoptosis- (Cd5l, Fcgr3 and Pycard) and immune- (Pycard, Lilrb3, Igh-6, Fcgr2b and MGC60843) related genes were commonly activated in both high- and low-dose-rate irradiated mice. The results suggest that carcinogenic cells have been removed by activated apoptosis and immune mechanisms, contributing to decreased thymic lymphoma and elongated life span. Functional studies for expressed genes associated with thymic lymphoma incidence in low-dose-rate exposed mice are currently under way. PMID:20726732

Shin, Suk Chul; Kang, Yu Mi; Kim, Hee Sun

2010-09-01

246

Metabolism, Body Size and Life Span: A Case Study in Evolutionarily Divergent Populations of the Garter Snake (Thamnophis elegans)  

E-print Network

of the Garter Snake (Thamnophis elegans) Anne Bronikowski1 and David Vleck Ecology, Evolution and Organismal of metabolism, life history and aging in the western terrestrial garter snake (Thamnophis elegans). Early

Bronikowski, Anne

247

Life-spans of human T-cell responses to determinants from the circumsporozoite proteins of Plasmodium falciparum and Plasmodium vivax.  

PubMed Central

The longevity of specific human memory T-cell responses is largely unknown. However, a knowledge of the duration of memory is important for understanding immunity to an organism and for planning vaccine intervention. To address this, we have examined T-cell memory to malaria by determining T-cell responses by subjects recently exposed to peptides spanning the circumsporozoite (CS) proteins of two species of malaria-causing organisms, Plasmodium falciparum and Plasmodium vivax. Responses to vivax CS peptides by exposed Thai subjects were more frequent than responses by nonexposed individuals, permitting identification of determinants seen by vivax-induced responses. At the population level, there appears to be life-long memory, as the time since individuals were exposed did not diminish responsiveness to these determinants. In contrast, falciparum-exposed subjects were largely indistinguishable from nonexposed controls in responsiveness to falciparum CS determinants. However, a single peptide (F16: DNEKLRKPKHKKLKQPGDGN) was recognized significantly more frequently by P. falciparum-exposed than nonexposed Thai subjects. T cells responsive to this peptide were CD450+ and produced gamma-interferon. In contrast to the response to the vivax determinants and the other falciparum determinants, responsiveness to F16 was undetectable or minimal 2 years after exposure. Our data provide the average life-spans of certain malaria-specific T cells and are consistent with, but do not prove, the hypothesis that antigenic persistence (in the form of P. vivax hypnozoites) correlates with persistence of human T-cell memory. Images PMID:7517041

Zevering, Y; Khamboonruang, C; Rungruengthanakit, K; Tungviboonchai, L; Ruengpipattanapan, J; Bathurst, I; Barr, P; Good, M F

1994-01-01

248

Human telomerase reverse transcriptase and glucose-regulated protein 78 increase the life span of articular chondrocytes and their repair potential  

PubMed Central

Background Like all mammalian cells, normal adult chondrocytes have a limited replicative life span, which decreases with age. To facilitate the therapeutic use of chondrocytes from older donors, a method is needed to prolong their life span. Methods We transfected chondrocytes with hTERT or GRP78 and cultured them in a 3-dimensional atelocollagen honeycomb-shaped scaffold with a membrane seal. Then, we measured the amount of nuclear DNA and glycosaminoglycans (GAGs) and the expression level of type II collagen as markers of cell proliferation and extracellular matrix formation, respectively, in these cultures. In addition, we allografted this tissue-engineered cartilage into osteochondral defects in old rabbits to assess their repair activity in vivo. Results Our results showed different degrees of differentiation in terms of GAG content between chondrocytes from old and young rabbits. Chondrocytes that were cotransfected with hTERT and GRP78 showed higher cellular proliferation and expression of type II collagen than those of nontransfected chondrocytes, regardless of the age of the cartilage donor. In addition, the in vitro growth rates of hTERT- or GRP78-transfected chondrocytes were higher than those of nontransfected chondrocytes, regardless of donor age. In vivo, the tissue-engineered cartilage implants exhibited strong repairing activity, maintained a chondrocyte-specific phenotype, and produced extracellular matrix components. Conclusions Focal gene delivery to aged articular chondrocytes exhibited strong repairing activity and may be therapeutically useful for articular cartilage regeneration. PMID:22472071

2012-01-01

249

Dmp53, basket and drICE gene knockdown and polyphenol gallic acid increase life span and locomotor activity in a Drosophila Parkinsons disease model  

PubMed Central

Understanding the mechanism(s) by which dopaminergic (DAergic) neurons are eroded in Parkinsons disease (PD) is critical for effective therapeutic strategies. By using the binary tyrosine hydroxylase (TH)-Gal4/UAS-X RNAi Drosophila melanogaster system, we report that Dmp53, basket and drICE gene knockdown in dopaminergic neurons prolong life span (p < 0.05; log-rank test) and locomotor activity (p < 0.05; ?2 test) in D. melanogaster lines chronically exposed to (1 mM) paraquat (PQ, oxidative stress (OS) generator) compared to untreated transgenic fly lines. Likewise, knockdown flies displayed higher climbing performance than control flies. Amazingly, gallic acid (GA) significantly protected DAergic neurons, ameliorated life span, and climbing abilities in knockdown fly lines treated with PQ compared to flies treated with PQ only. Therefore, silencing specific gene(s) involved in neuronal death might constitute an excellent tool to study the response of DAergic neurons to OS stimuli. We propose that a therapy with antioxidants and selectively switching off death genes in DAergic neurons could provide a means for pre-clinical PD individuals to significantly ameliorate their disease condition. PMID:24385865

Ortega-Arellano, Hector Flavio; Jimenez-Del-Rio, Marlene; Velez-Pardo, Carlos

2013-01-01

250

Budding Yeast SSD1-V Regulates Transcript Levels of Many Longevity Genes and Extends Chronological Life Span in Purified Quiescent Cells  

PubMed Central

Ssd1 is an RNA-binding protein that affects literally hundreds of different processes and is polymorphic in both wild and lab yeast strains. We have used transcript microarrays to compare mRNA levels in an isogenic pair of mutant (ssd1-d) and wild-type (SSD1-V) cells across the cell cycle. We find that 15% of transcripts are differentially expressed, but there is no correlation with those mRNAs bound by Ssd1. About 20% of cell cycle regulated transcripts are affected, and most show sharper amplitudes of oscillation in SSD1-V cells. Many transcripts whose gene products influence longevity are also affected, the largest class of which is involved in translation. Ribosomal protein mRNAs are globally down-regulated by SSD1-V. SSD1-V has been shown to increase replicative life span and we show that SSD1-V also dramatically increases chronological life span (CLS). Using a new assay of CLS in pure populations of quiescent prototrophs, we find that the CLS for SSD1-V cells is twice that of ssd1-d cells. PMID:19570907

Li, Lihong; Lu, Yong; Qin, Li-Xuan; Bar-Joseph, Ziv; Werner-Washburne, Margaret

2009-01-01

251

Extracts of Cistanche deserticola Can Antagonize Immunosenescence and Extend Life Span in Senescence-Accelerated Mouse Prone 8 (SAM-P8) Mice  

PubMed Central

The senescence accelerated mouse prone 8 substrain (SAM-P8), widely accepted as an animal model for studying aging and antiaging drugs, was used to examine the effects of dietary supplementation with extracts of Cistanche deserticola (ECD) which has been used extensively in traditional Chinese medicine because of its perceived ability to promote immune function in the elderly. Eight-month-old male SAM-P8 mice were treated with ECD by daily oral administrations for 4 weeks. The results showed that dietary supplementation of 150?mg/kg and 450?mg/kg of ECD could extend the life span measured by Kaplan-Meier survival analysis in dose-dependent manner. Dietary supplementation of SAM-P8 mice for 4 weeks with 100, 500, and 2500?mg/kg of ECD was shown to result in significant increases in both naive T and natural killer cells in blood and spleen cell populations. In contrast, peripheral memory T cells and proinflammatory cytokine, IL-6 in serum, were substantially decreased in the mice that ingested 100 and 500?mg/kg of ECD daily. Additionally, Sca-1 positive cells, the recognized progenitors of peripheral naive T cells, were restored in parallel. Our results provide clear experimental support for long standing clinical observational studies showing that Cistanche deserticola possesses significant effects in extending life span and suggest this is achieved by antagonizing immunosenescence. PMID:24523825

Zhang, Ke; Ma, Xu; He, Wenjun; Li, Haixia; Han, Shuyan; Jiang, Yong; Wu, Hounan; Han, Li; Uotsu, Nobuo; Yamaguchi, Kohji; Ma, Zhizhong; Tu, Pengfei

2014-01-01

252

Biodemography of a long-lived tephritid: Reproduction and longevity in a large cohort of female Mexican fruit flies, Anastrepha ludens  

E-print Network

U N C O R R EC TED PR O O F Biodemography of a long-lived tephritid: Reproduction and longevity reproductive rates, and life span were recorded in a laboratory cohort of Mexican fruit flies consisting of egg laying at early ages and both subsequent reproduction and remaining longevity. Discussion includes

Sentürk, Damla

253

The Study of Life Review. An Approach to the Investigation of Intellectual Development across the Life Span. Studien und Berichte 47.  

ERIC Educational Resources Information Center

A study looked for age differences in the quality of responses to the Life Review Task (LRT), studied the LRT itself as a tool for exploring wisdom and intellectual functioning in adulthood, and considered personality characteristics and life experience as alternative predictors of response quality. Sixty-three West German women of different ages

Staudinger, Ursula M.

254

Enhanced early-life nutrition promotes hormone production and reproductive development in Holstein bulls.  

PubMed

Holstein bull calves often reach artificial insemination centers in suboptimal body condition. Early-life nutrition is reported to increase reproductive performance in beef bulls. The objective was to determine whether early-life nutrition in Holstein bulls had effects similar to those reported in beef bulls. Twenty-six Holstein bull calves were randomly allocated into 3 groups at approximately 1 wk of age to receive a low-, medium-, or high-nutrition diet, based on levels of energy and protein, from 2 to 31 wk of age. Calves were on their respective diets until 31 wk of age, after which they were all fed a medium-nutrition diet. To evaluate secretion profiles and concentrations of blood hormones, a subset of bulls was subjected to intensive blood sampling every 4 wk from 11 to 31 wk of age. Testes of all bulls were measured once a month; once scrotal circumference reached 26cm, semen collection was attempted (by electroejaculation) every 2 wk to confirm puberty. Bulls were maintained until approximately 72 wk of age and then slaughtered at a local abattoir. Testes were recovered and weighed. Bulls fed the high-nutrition diet were younger at puberty (high=324.3 d, low=369.3 d) and had larger testes for the entire experimental period than bulls fed the low-nutrition diet. Bulls fed the high-nutrition diet also had an earlier and more substantial early rise in LH than those fed the low-nutrition diet and had increased concentrations of insulin-like growth factor-I (IGF-I) earlier than the bulls fed the low-nutrition diet. Furthermore, we detected a temporal association between increased IGF-I concentrations and an early LH rise in bulls fed the high-nutrition diet. Therefore, we inferred that IGF-I had a role in regulating the early gonadotropin rise (in particular, LH) and thus reproductive development of Holstein bulls. Overall, these results support our hypothesis that Holstein bull calves fed a high-nutrition diet reach puberty earlier and have larger testes than those fed a low-nutrition diet, and they provide clear evidence that nutritional modulation of Holstein bull calves during early life has profound effects on reproductive development. PMID:25497791

Dance, Alysha; Thundathil, Jacob; Wilde, Randy; Blondin, Patrick; Kastelic, John

2015-02-01

255

Quality of Life, Anxiety and Depression in Turkish Women Prior to Receiving Assisted Reproductive Techniques  

PubMed Central

Background: This study evaluated the quality of life and anxiety-depression levels of patients prior to receiving assisted reproductive techniques. Materials and Methods: This cross-sectional research was conducted in the In-Vitro Fertilization Unit of a private Universitys Faculty of Medicine, Department of Obstetrics and Gynecology. Study participants consisted of 160 individuals diagnosed as infertile whose treatment plans were determined, as well as 160 reportedly healthy fertile individuals (n=320). Each participant completed the Patient Identification Form, Beck Anxiety Inventory, Beck Depression Inventory and Quality of Life Scale questionaires. Results: The results of this study indicate a higher prevalence of depression and anxiety in the infertile group (p<0.05). Also, quality of life scores were found to be lower in the infertile group (p<0.05). Conclusion: Individuals who experience infertility need psychological support in order to overcome the psycho-social difficulties they experience. It is essential to have studies that stress the importance of integrating psychological and emotional support into clinical practice.

Pinar, Gul; Zeyneloglu, Hulusi Bulent

2012-01-01

256

Reproductive versus somatic tissue growth during the life cycle of the cuttlefish Sepia pharaonis Ehrenberg, 1831  

Microsoft Academic Search

The effect of maturation on relative growth of somatic tissues was investigated by measuring and compar- ing monthly changes in dry weight of somatic tissues and reproductive or- gans. In both sexes, reproductive tis- sues grew in relation to total body mass; at maturity female reproductive tissue was 16% of total dry body mass, whereas male reproductive tissue was 2.6%.

Howaida R. Gabr; Roger T. Hanlon; Salah G. El-Etreby; Mahmoud H. Hanafy

257

Extension of the replicative life span of human diploid fibroblasts by inhibition of the p33ING1 candidate tumor suppressor.  

PubMed Central

Previous studies suggest that tumor suppressors may play significant roles in blocking the growth of cells during cellular senescence. We therefore studied the potential involvement of a novel growth inhibitor and candidate tumor suppressor gene called ING1, which we have cloned recently (I. Garkavtsev, A. Kazarov, A. Gudkov, and K. Riabowol, Nat. Genet. 14:415-420, 1996), in the process of cellular senescence. Our results show that the RNA and protein levels of ING1 were 8- to 10-fold higher in senescent cells than in young, proliferation-competent human diploid fibroblasts. Expression of the nuclear p33ING1 protein was regulated during the cell cycle, reaching maximal levels during DNA synthesis. Chronic expression of antisense ING1 RNA reproducibly resulted in extension of the proliferative life span of normal human fibroblasts by approximately seven population doublings. PMID:9121449

Garkavtsev, I; Riabowol, K

1997-01-01

258

Male alternative reproductive behaviours in a Mediterranean wrasse, Symphodus ocellatus: Evidence from otoliths for multiple life-history pathways  

Microsoft Academic Search

Although alternative reproductive behaviours have been studied extensively, it has only been possible in a few cases to document the underlying life-history pathways and factors that determine their expression. In Symphodus ocellatus, a Mediterranean wrasse, males adopt a variety of behaviours. Within a season, they may invest in territory defence, nest building and broodcare (nesting males); join nesting males in

Suzanne H. Alonzo; Michael Taborsky; Peter Wirtz

259

Character strengths and well-being across the life span: data from a representative sample of German-speaking adults living in Switzerland.  

PubMed

Character strengths are positive, morally valued traits of personality. This study aims at assessing the relationship between character strengths and subjective well-being (i.e., life satisfaction, positive and negative affect) in a representative sample of German-speaking adults living in Switzerland (N = 945). We further test whether this relationship is consistent at different stages in life. Results showed that hope, zest, love, social intelligence and perseverance yielded the highest positive correlations with life satisfaction. Hope, zest, humor, gratitude and love presented the highest positive correlations with positive affect. Hope, humor, zest, honesty, and open-mindedness had the highest negative correlations with negative affect. When examining the relationship between strengths and well-being across age groups, in general, hope, zest and humor consistently yielded the highest correlations with well-being. Additionally, in the 27-36 years group, strengths that promote commitment and affiliation (i.e., kindness and honesty) were among the first five positions in the ranking of the relationship between strengths and well-being. In the 37-46 years group, in addition to hope, zest and humor, strengths that promote the maintenance of areas such as family and work (i.e., love, leadership) were among the first five positions in the ranking. Finally, in the 47-57 years group, in addition to hope, zest and humor, strengths that facilitate integration and a vital involvement with the environment (i.e., gratitude, love of learning) were among the first five positions in the ranking. This study partially supports previous findings with less representative samples on the association between character strengths and well-being, and sheds light on the relative importance of some strengths over others for well-being across the life span. PMID:25408678

Martnez-Mart, Mara L; Ruch, Willibald

2014-01-01

260

Increased production of mitochondrial reactive oxygen species and reduced adult life span in an insecticide-resistant strain of Anopheles gambiae.  

PubMed

Control of the malaria vector An. gambiae is still largely obtained through chemical intervention using pyrethroids, such as permethrin. However, strains of An. gambiae that are resistant to the toxic effects of pyrethroids have become widespread in several endemic areas over the last decade. The objective of this study was to assess differences in five life-history traits (larval developmental time and the body weight, fecundity, hatch rate, and longevity of adult females) and energy metabolism between a strain of An. gambiae that is resistant to permethrin (RSP), due to knockdown resistance and enhanced metabolic detoxification, and a permethrin susceptible strain reared under laboratory conditions. We also quantified the expression levels of five antioxidant enzyme genes: GSTe3, CAT, GPXH1, SOD1, and SOD2. We found that the RSP strain had a longer developmental time than the susceptible strain. Additionally, RSP adult females had higher wet body weight and increased water and glycogen levels. Compared to permethrin susceptible females, RSP females displayed reduced metabolic rate and mitochondrial coupling efficiency and higher mitochondrial ROS production. Furthermore, despite higher levels of GSTe3 and CAT transcripts, RSP females had a shorter adult life span than susceptible females. Collectively, these results suggest that permethrin resistance alleles might affect energy metabolism, oxidative stress, and adult survival of An. gambiae. However, because the strains used in this study differ in their genetic backgrounds, the results need to be interpreted with caution and replicated in other strains to have significant implications for malaria transmission and vector control. PMID:24555527

Otali, D; Novak, R J; Wan, W; Bu, S; Moellering, D R; De Luca, M

2014-06-01

261

Assessing the burden of sexual and reproductive ill-health: questions regarding the use of disability-adjusted life years.  

PubMed Central

The use of the disability-adjusted life year (DALY) as the unit in which to calculate the burden of disease associated with reproductive ill-health has given rise to considerable debate. Criticisms include the failure to address the problem of missing and inadequate epidemiological data, inability to deal adequately with co-morbidities, and lack of transparency in the process of ascribing disability weights to sexual and reproductive health conditions. Many of these criticisms could be addressed within the current DALY framework and a number of suggestions to do so are made. These suggestions include: (1) developing an international research strategy to determine the incidence and prevalence of reproductive ill-health and diseases, including the risk of long-term complications; (2) undertaking a research strategy using case studies, population-based surveillance data and longitudinal studies to identify, evaluate and utilize more of the existing national data sources on sexual and reproductive health; (3) comprehensively mapping the natural history of sexual and reproductive health conditions--in males and in females--and their sequelae, whether physical or psychological; (4) developing valuation instruments that are adaptable for both chronic and acute health states, that reflect a range of severity for each health state and can be modified to reflect prognosis; (5) undertaking a full review of the DALY methodology to determine what changes may be made to reduce sources of methodological and gender bias. Despite the many criticisms of the DALY as a measurement unit, it represents a major conceptual advance since it permits the combination of life expectancy and levels of dysfunction into a single measure. Measuring reproductive ill-health by counting deaths alone is inadequate for a proper understanding of the dimensions of the problem because of the young age of many of the deaths associated with reproductive ill-health and the large component of years lived with disability from many of the associated conditions. PMID:10859859

AbouZahr, C.; Vaughan, J. P.

2000-01-01

262

Resource allocation in a social wasp: effects of breeding system and life cycle on reproductive decisions  

E-print Network

clumping within the female reproductive tract. Finally, we tested if colony sex ratio conformed investment in growth, by producing sterile workers and soldiers, and investment in reproduction, by producing

Yi, Soojin

263

Life-cycle exposure to the estrogenic mycotoxin zearalenone affects zebrafish (Danio rerio) development and reproduction.  

PubMed

Zearalenone (ZON) is one of the worldwide most common mycotoxin and exhibits estrogenic activity in the range of natural steroid estrogens. The occurrence of ZON has been reported in soil, drainage water, wastewater effluents, and rivers, but its ecotoxicological effects on fish have hardly been investigated. The consequences of continuous long-term ZON exposure, including a subsequent depuration period, as well as transgenerational effects of F0 short-term exposure on F1 generation were investigated. Effects on growth, reproduction activity, physiology, and morphology of zebrafish (Danio rerio) were examined in a 182 day live-cycle experiment. Life-long exposure to ZON for 140 days increased wet weight, body length, and condition factor of female fish at 1000 ng/L, and sex ratio was shifted toward female from 320 ng/L ZON. Only females at 1000 ng/L ZON revealed a 1.5-fold induction of plasma vitellogenin (VTG). Relative fecundity at 1000 ng/L recovered significantly during the depuration period. An increased condition factor in adult female F1 fish implies that exposure of F0 generation to 1000 ng/L ZON affected growth of F1 generation. A negative correlation between relative fecundity in the F1 generation (all groups exposed to 320 ng/L ZON) and the nominal ZON concentrations of the F0 exposure might indicate an influence of F0 exposure on reproductive performance of F1 generation. No exposure scenario affected fertility, hatch, embryo survival, and gonad morphology of zebrafish. Evaluating the environmental relevance of this data, the risk for fish to be harmed by exposure to ZON solely seems rather marginal, but ZON might contribute to the overall estrogenicity in the environment. 2011 Wiley Periodicals, Inc. Environ Toxicol 2013. PMID:21695757

Schwartz, Patrick; Bucheli, Thomas D; Wettstein, Felix E; Burkhardt-Holm, Patricia

2013-05-01

264

The control processes and subjective well-being of Chinese teachers: evidence of convergence with and divergence from the key propositions of the motivational theory of life-span development.  

PubMed

An analytical review of the motivational theory of life-span development reveals that this theory has undergone a series of elegant theoretical integrations. Its claim to universality nonetheless brings forth unresolved controversies. With the purpose of scrutinizing the key propositions of this theory, an empirical study was designed to examine the control processes and subjective well-being of Chinese teachers (N = 637). The OPS-Scales (Optimization in Primary and Secondary Control Scales) for the Domain of Teaching were constructed to assess patterns of control processes. Three facets of subjective well-being were investigated with the Positive and Negative Affect Schedule, the Life Satisfaction Scale, and the Subjective Vitality Scale. The results revealed certain aspects of alignment with and certain divergences from the key propositions of the motivational theory of life-span development. Neither "primacy of primary control" nor "primacy of secondary control" was clearly supported. Notably, using different criteria for subjective well-being yielded different subtypes of primary and secondary control as predictors. The hypothesized life-span trajectories of primary and secondary control received limited support. To advance the theory in this area, we recommend incorporating Lakatos' ideas about sophisticated falsification by specifying the hard core of the motivational theory of life-span development and articulating new auxiliary hypotheses. PMID:24904483

Wong, Wan-Chi; Li, Yin; Sun, Xiaoyan; Xu, Huanu

2014-01-01

265

A Widespread Chromosomal Inversion Polymorphism Contributes to a Major Life-History Transition, Local Adaptation, and Reproductive Isolation  

PubMed Central

The role of chromosomal inversions in adaptation and speciation is controversial. Historically, inversions were thought to contribute to these processes either by directly causing hybrid sterility or by facilitating the maintenance of co-adapted gene complexes. Because inversions suppress recombination when heterozygous, a recently proposed local adaptation mechanism predicts that they will spread if they capture alleles at multiple loci involved in divergent adaptation to contrasting environments. Many empirical studies have found inversion polymorphisms linked to putatively adaptive phenotypes or distributed along environmental clines. However, direct involvement of an inversion in local adaptation and consequent ecological reproductive isolation has not to our knowledge been demonstrated in nature. In this study, we discovered that a chromosomal inversion polymorphism is geographically widespread, and we test the extent to which it contributes to adaptation and reproductive isolation under natural field conditions. Replicated crosses between the prezygotically reproductively isolated annual and perennial ecotypes of the yellow monkeyflower, Mimulus guttatus, revealed that alternative chromosomal inversion arrangements are associated with life-history divergence over thousands of kilometers across North America. The inversion polymorphism affected adaptive flowering time divergence and other morphological traits in all replicated crosses between four pairs of annual and perennial populations. To determine if the inversion contributes to adaptation and reproductive isolation in natural populations, we conducted a novel reciprocal transplant experiment involving outbred lines, where alternative arrangements of the inversion were reciprocally introgressed into the genetic backgrounds of each ecotype. Our results demonstrate for the first time in nature the contribution of an inversion to adaptation, an annual/perennial life-history shift, and multiple reproductive isolating barriers. These results are consistent with the local adaptation mechanism being responsible for the distribution of the two inversion arrangements across the geographic range of M. guttatus and that locally adaptive inversion effects contribute directly to reproductive isolation. Such a mechanism may be partially responsible for the observation that closely related species often differ by multiple chromosomal rearrangements. PMID:20927411

Lowry, David B.; Willis, John H.

2010-01-01

266

Cardiovascular determinants of life span  

Microsoft Academic Search

The prevalence of cardiovascular diseases rises with aging and is one of the main causes of mortality in western countries.\\u000a In view of the progressively aging population, there is an urge for a better understanding of age-associated cardiovascular\\u000a diseases and its underlying molecular mechanisms. The risk factors for cardiovascular diseases include unhealthy diet, diabetes,\\u000a obesity, smoking, alcohol consumption, physical inactivity,

Yi Shi; Giovanni G. Camici; Thomas F. Lscher

2010-01-01

267

Late-life effects on rat reproductive system after developmental exposure to mixtures of endocrine disrupters.  

PubMed

This study examined late-life effects of perinatal exposure of rats to a mixture of endocrine-disrupting contaminants. Four groups of 14 time-mated Wistar rats were exposed by gavage from gestation day 7 to pup day 22 to a mixture of 13 anti-androgenic and estrogenic chemicals including phthalates, pesticides, u.v.-filters, bisphenol A, parabens, and the drug paracetamol. The groups received vehicle (control), a mixture of all 13 chemicals at 150-times (TotalMix150) or 450-times (TotalMix450) high-end human exposure, or 450-times a mixture of nine predominantly anti-androgenic chemicals (AAMix450). Onset of puberty and estrous cyclicity at 9 and 12 months of age were assessed. Few female offspring showed significantly regular estrus cyclicity at 12 months of age in the TotalMix450 and AAMix450 groups compared with controls. In 19-month-old male offspring, epididymal sperm counts were lower than controls, and in ventral prostate an overrepresentation of findings related to hyperplasia was observed in exposed groups compared with controls, particularly in the group dosed with anti-androgens. A higher incidence of pituitary adenoma at 19 months of age was found in males and females in the AAMix450 group. Developmental exposure of rats to the highest dose of a human-relevant mixture of endocrine disrupters induced adverse effects late in life, manifested as earlier female reproductive senescence, reduced sperm counts, higher score for prostate atypical hyperplasia, and higher incidence of pituitary tumors. These delayed effects highlight the need for further studies on the role of endocrine disrupters in hormone-related disorders in aging humans. PMID:24287426

Isling, Louise Krag; Boberg, Julie; Jacobsen, Pernille Rosenskjold; Mandrup, Karen Riiber; Axelstad, Marta; Christiansen, Sofie; Vinggaard, Anne Marie; Taxvig, Camilla; Kortenkamp, Andreas; Hass, Ulla

2014-01-01

268

Increased production of mitochondrial reactive oxygen species and reduced adult life span in an insecticide-resistant strain of Anopheles gambiae  

PubMed Central

Control of the malaria vector An. gambiae is still largely obtained through chemical intervention using pyrethroids, such as permethrin. However, strains of An. gambiae that are resistant to the toxic effects of pyrethroids have become widespread in several endemic areas over the last decade. The objective of this study was to assess differences in five life-history traits (larval developmental time and the body weight, fecundity, hatch rate, and longevity of adult females) and energy metabolism between a strain of An. gambiae that is resistant to permethrin (RSP), due to knockdown resistance and enhanced metabolic detoxification, and a permethrin susceptible strain reared under laboratory conditions. We also quantified the expression levels of five antioxidant enzyme genes: GSTe3, CAT, GPXH1, SOD1, and SOD2. We found that the RSP strain had a longer developmental time than the susceptible strain. Additionally, RSP adult females had higher wet body weight and increased water and glycogen levels. Compared to permethrin susceptible females, RSP females displayed reduced metabolic rate and mitochondrial coupling efficiency and higher mitochondrial ROS production. Furthermore, despite higher levels of GSTe3 and CAT transcripts, RSP females had a shorter adult life span than susceptible females. Collectively, these results suggest that permethrin resistance alleles might affect energy metabolism, oxidative stress, and adult survival of An. gambiae. However, because the strains used in this study differ in their genetic backgrounds, the results need to be interpreted with caution and replicated in other strains in order to have significant implications for malaria transmission and vector control. PMID:24555527

Otali, Dennis; Novak, Robert J.; Wan, Wen; Bu, Su; Moellering, Douglas R.; De Luca, Maria

2014-01-01

269

Loss of Trabid, a New Negative Regulator of the Drosophila Immune-Deficiency Pathway at the Level of TAK1, Reduces Life Span  

PubMed Central

A relatively unexplored nexus in Drosophila Immune deficiency (IMD) pathway is TGF-beta Activating Kinase 1 (TAK1), which triggers both immunity and apoptosis. In a cell culture screen, we identified that Lysine at position 142 was a K63-linked Ubiquitin acceptor site for TAK1, required for signalling. Moreover, Lysine at position 156 functioned as a K48-linked Ubiquitin acceptor site, also necessary for TAK1 activity. The deubiquitinase Trabid interacted with TAK1, reducing immune signalling output and K63-linked ubiquitination. The three tandem Npl4 Zinc Fingers and the catalytic Cysteine at position 518 were required for Trabid activity. Flies deficient for Trabid had a reduced life span due to chronic activation of IMD both systemically as well as in their gut where homeostasis was disrupted. The TAK1-associated Binding Protein 2 (TAB2) was linked with the TAK1-Trabid interaction through its Zinc finger domain that pacified the TAK1 signal. These results indicate an elaborate and multi-tiered mechanism for regulating TAK1 activity and modulating its immune signal. PMID:24586180

Ligoxygakis, Petros

2014-01-01

270

Reproductive adaptation in Drosophila exposed to oxygen-enriched atmospheres  

NASA Technical Reports Server (NTRS)

Ten successive generations of a Drosophila melanogaster population were exposed to an atmospheric mix of 50% oxygen/50% nitrogen at standard pressure. This atmospheric mix has been shown to be toxic to this species and causes significantly shortened life span. By the fifth generation, survivorship and life span for the first 25-30 days were identical to control populations and total life span was shorter by only a few days. Egg-laying rates were stable in the experimental populations but below those of the controls. Hatching success was identical between experimental and control populations. Even though the egg-laying rates were lower in 50% oxygen, it was concluded that the population had adapted and could maintain a stable population in these conditions. The near-normal life spans, normal hatching rates, and overall population stability, exhibited following five generations of adaptation, were considered sufficient to allow continued reproduction in spite of a reduced egg-laying rate.

Kloek, G.; Winkle, L.

1979-01-01

271

Effects of triclosan on the early life stages and reproduction of medaka Oryzias latipes and induction of hepatic vitellogenin  

Microsoft Academic Search

Triclosan (2,4,4?-trichloro-2?-hydroxydiphenyl ether) is widely used as antibacterial agent in various industrial products, such as textile goods, soap, shampoo, liquid toothpaste and cosmetics, and often detected in wastewater effluent. In this study, the effects of TCS on the early life stages and reproduction of medaka (Oryzias latipes) were investigated. The 96-h median lethal concentration value of TCS for 24-h-old larvae

Hiroshi Ishibashi; Naomi Matsumuraa; Masashi Hirano; Munekazu Matsuokaa; Hideki Shiratsuchi; Yasuhiro Ishibashi; Yuji Takao; Koji Arizono

2004-01-01

272

Sexual reproduction, in one form or another, is present in all branches of the tree of life. The fact that sex is  

E-print Network

Sexual reproduction, in one form or another, is present in all branches of the tree of life advantage that explains its evolutionary success. In fact, sexual reproduction often comes with substantial, a mutation that has the sole effect of causing females to reproduce asexually will inevitably succeed because

Elena, Santiago F.

273

Life history plasticity after attaining a dietary threshold for reproduction is associated with protein storage in flesh flies  

PubMed Central

Summary Body condition affects the timing and magnitude of life history transitions. Therefore, identifying proximate mechanisms involved in assessing condition is critical to understanding how these mechanisms affect the expression of life history plasticity. Nutrient storage is an important body condition parameter, likely playing roles in both attaining minimum body-condition thresholds for life history transitions and expression of life history traits. We manipulated protein availability for females of the flesh fly Sarcophaga crassipalpis to determine whether reproductive timing and output would remain plastic or become fixed. Liver was provided for 0, 2, 4, or 6 days of adult pre-reproductive development. Significantly, liver was removed after the feeding threshold had been attained and females had committed to producing a clutch. We also identified the major storage proteins and monitored their abundances, because protein stores may serve as an index of body condition and therefore may play an important role in life history transitions and plasticity. Flesh flies showed clear post-threshold plasticity in reproductive timing. Females fed protein for 2 days took ~30% longer to provision their clutch than those fed for 4 or 6 days. Observations of oogenesis showed the 2-day group expressed a different developmental program including slower egg provisioning. Protein availability also affected reproductive output. Females fed protein for 2 days produced ~20% fewer eggs than females fed 4 or 6 days. Six-day treated females provisioned larger eggs than 4-day treated females, followed by 2-day treated females with the smallest eggs. Two storage proteins were identified, LSP-1 and LSP-2. LSP-2 accumulation differed across feeding treatments. The 2- and 4-day treatment groups accumulated LSP-2 stores but depleted them during provisioning of the first clutch, whereas the 6-day group accumulated the greatest quantity of LSP-2 and had substantial LSP-2 stores remaining at the end of the clutch. This pattern of accumulation and depletion suggests that LSP-2 could play roles in both provisioning the current clutch and future clutches, making it a good candidate molecule for affecting reproductive timing and allotment. LSP-1 was not associated with post-threshold plasticity; it was carried over from larval feeding into adulthood and depleted uniformly across all feeding groups. PMID:19789714

Hahn, Daniel A.; James, Laura N.; Milne, Kathy R.; Hatle, John D.

2009-01-01

274

Patterns of hippocampal-neocortical interactions in the retrieval of episodic autobiographical memories across the entire life-span of aged adults  

PubMed Central

We previously demonstrated that Episodic Autobiographical Memories (EAMs) rely on a network of brain regions comprising the medial temporal lobe (MTL) and distributed neocortical regions regardless of their remoteness. The findings supported the model of memory consolidation which proposes a permanent role of MTL during EAM retrieval (Multiple-Trace Theory or MTT) rather than a temporary role (standard model). Our present aim was to expand the results by examining the interactions between the MTL and neocortical regions (or MTL-neocortical links) during EAM retrieval with varying retention intervals. We used an experimental paradigm specially designed to engage aged participants in the recollection of EAMs, extracted from five different time-periods, covering their whole life-span, in order to examine correlations between activation in the MTL and neocortical regions. The nature of the memories was checked at debriefing by means of behavioral measures to control the degree of episodicity and properties of memories. Targeted correlational analyses carried out on the MTL, frontal, lateral temporal and posterior regions revealed strong links between the MTL and neocortex during the retrieval of both recent and remote EAMs, challenging the standard model of memory consolidation and supporting MTT instead. Further confirmation was given by results showing that activation in the left and right hippocampi significantly correlated during the retrieval of both recent and remote memories. Correlations among extra-MTL neocortical regions also emerged for all time-periods, confirming the critical role of the prefrontal, temporal (lateral temporal cortex and temporal pole), precuneus and posterior cingulate regions in EAM retrieval. Overall, this paper emphasizes the role of a bilateral network of MTL and neocortical areas whose activation correlate during the recollection of rich phenomenological recent and remote EAMs. PMID:19338022

Viard, Armelle; Lebreton, Karine; Chtelat, Gal; Desgranges, Batrice; Landeau, Brigitte; Young, Alan; De La Sayette, Vincent; Eustache, Francis; Piolino, Pascale

2010-01-01

275

Temperature-related variation in growth rate, size, maturation and life span in a marine herbivorous fish over a latitudinal gradient.  

PubMed

In ectotherms, growth rate, body size and maturation rate covary with temperature, with the direction and magnitude of variation predicted by the Temperature-Size Rule (TSR). Nutritional quality or availability of food, however, may vary over latitudinal gradients, resulting in ambiguous effects on body size and maturation rate. The Temperature-Constraint Hypothesis (TCH) predicts that marine herbivorous ectotherms are nutritionally compromised at latitudes exceeding 30. This provides an opportunity to resolve the contrasting demographic responses of ectotherms to variation in temperature and nutritional status over latitudinal gradients. This study uses analysis of demographic rates to evaluate the predictions of the TSR in a marine herbivorous ectotherm sampled over a significant latitudinal gradient. The direction and magnitude of demographic variation was established in the marine herbivorous fish, Odax pullus (the butterfish), and compared with that of a phylogenetically related but trophically distinct species, the carnivorous Notolabrus fucicola (the banded wrasse). Both species were sampled at three locations across the length of New Zealand covering latitudes between 35S and 49S. Growth rate, mean size-at-age, age- and size-at-maturity, life span and abundance were estimated for each species at each location. Demographic traits of both taxa varied with latitude. Both species showed slower initial growth rates, and matured later at a larger body size at higher latitudes than populations sampled at lower latitudes. In addition, abundances increased significantly at higher latitudes in both species. These results were consistent with the TSR but not with the TCH, confirming that nutritional ecology (herbivore vs. carnivory) did not determine demographic patterns over a biologically significant latitudinal gradient. Results from this study suggest that the absence of herbivorous reef fishes from the higher latitudes of the Northern Hemisphere may not reflect a general physiological mechanism as suggested by the TCH and highlights the need to clarify the evolutionary histories of the marine biota of each hemisphere. PMID:24252150

L Trip, Elizabeth D; Clements, Kendall D; Raubenheimer, David; Choat, J Howard

2013-11-19

276

Correlations of life-span variation parameters in 128 successive generations of Drosophila melanogaster with changes in atmospheric pressure and geomagnetic activity.  

PubMed

Correlations between the parameters of life-span (LS) distribution of Drosophila melanogaster, including mean LS (MLS) and the time of 10 and 90% population mortality, and some geophysical parameters that are usually beyond the control of researchers dealing with laboratory cultures, including atmospheric pressure, solar activity indices (Wolf's sunspot numbers and 2,800-MHz radio flux), and geomagnetic activity (planetary index, K(p)), were studied. Geophysical data were obtained from free-access official web sites of the National Oceanic & Atmospheric Administration of the US Department of Commerce and the Institute of Terrestrial Magnetism and Radiowave Propagation of the Russian Academy of Sciences. The geophysical parameters were calculated only for the period corresponding to 10 days of preimaginal development of the flies from egg to imago. Canonical correlation analysis, calculation of the non-parametric Spearman rank-order correlation coefficients, and graphical data analysis were used. Highly significant correlations between parameters of LS distribution in males and females and environmental factors, such as the atmospheric pressure on the 4th and 5th day of development and geomagnetic activity indices (K(p)) on the 6th and 10th day of development were found, with correlation coefficients varying from 0.31 to 0.37 (P<0.02). Assuming a causal relationship between geophysical factors and LS, it may be hypothesized that energetically weak environmental factors determine the formation of LS oscillatory dynamics in laboratory populations. The possible mechanisms underlying the contribution of these environmental factors to the LS variation in successive generations are discussed. PMID:15864403

Izmaylov, D M; Obukhova, L K; Konradov, A A

2005-05-01

277

Perceived Risk of Predation Affects Reproductive Life-History Traits in Gambusia holbrooki, but Not in Heterandria formosa  

PubMed Central

Key to predicting impacts of predation is understanding the mechanisms through which predators impact prey populations. While consumptive effects are well-known, non-consumptive predator effects (risk effects) are increasingly being recognized as important. Studies of risk effects, however, have focused largely on how trade-offs between food and safety affect fitness. Less documented, and appreciated, is the potential for predator presence to directly suppress prey reproduction and affect life-history characteristics. For the first time, we tested the effects of visual predator cues on reproduction of two prey species with different reproductive modes, lecithotrophy (i.e. embryonic development primarily fueled by yolk) and matrotrophy (i.e. energy for embryonic development directly supplied by the mother to the embryo through a vascular connection). Predation risk suppressed reproduction in the lecithotrophic prey (Gambusia holbrokii) but not the matrotroph (Heterandria formosa). Predator stress caused G. holbrooki to reduce clutch size by 43%, and to produce larger and heavier offspring compared to control females. H. formosa, however, did not show any such difference. In G. holbrooki we also found a significantly high percentage (14%) of stillbirths in predator-exposed treatments compared to controls (2%). To the best of our knowledge, this is the first direct empirical evidence of predation stress affecting stillbirths in prey. Our results suggest that matrotrophy, superfetation (clutch overlap), or both decrease the sensitivity of mothers to environmental fluctuation in resource (food) and stress (predation risk) levels compared to lecithotrophy. These mechanisms should be considered both when modeling consequences of perceived risk of predation on prey-predator population dynamics and when seeking to understand the evolution of reproductive modes. PMID:24551171

Mukherjee, Shomen; Heithaus, Michael R.; Trexler, Joel C.; Ray-Mukherjee, Jayanti; Vaudo, Jeremy

2014-01-01

278

Perceived risk of predation affects reproductive life-history traits in Gambusia holbrooki, but not in Heterandria formosa.  

PubMed

Key to predicting impacts of predation is understanding the mechanisms through which predators impact prey populations. While consumptive effects are well-known, non-consumptive predator effects (risk effects) are increasingly being recognized as important. Studies of risk effects, however, have focused largely on how trade-offs between food and safety affect fitness. Less documented, and appreciated, is the potential for predator presence to directly suppress prey reproduction and affect life-history characteristics. For the first time, we tested the effects of visual predator cues on reproduction of two prey species with different reproductive modes, lecithotrophy (i.e. embryonic development primarily fueled by yolk) and matrotrophy (i.e. energy for embryonic development directly supplied by the mother to the embryo through a vascular connection). Predation risk suppressed reproduction in the lecithotrophic prey (Gambusia holbrokii) but not the matrotroph (Heterandria formosa). Predator stress caused G. holbrooki to reduce clutch size by 43%, and to produce larger and heavier offspring compared to control females. H. formosa, however, did not show any such difference. In G. holbrooki we also found a significantly high percentage (14%) of stillbirths in predator-exposed treatments compared to controls (2%). To the best of our knowledge, this is the first direct empirical evidence of predation stress affecting stillbirths in prey. Our results suggest that matrotrophy, superfetation (clutch overlap), or both decrease the sensitivity of mothers to environmental fluctuation in resource (food) and stress (predation risk) levels compared to lecithotrophy. These mechanisms should be considered both when modeling consequences of perceived risk of predation on prey-predator population dynamics and when seeking to understand the evolution of reproductive modes. PMID:24551171

Mukherjee, Shomen; Heithaus, Michael R; Trexler, Joel C; Ray-Mukherjee, Jayanti; Vaudo, Jeremy

2014-01-01

279

Reproductive mode and life cycle of the ash dieback pathogen Hymenoscyphus pseudoalbidus.  

PubMed

Ash dieback caused by the fungal pathogen Hymenoscyphus pseudoalbidus is currently ravaging in Europe, killing Fraxinus excelsior and Fraxinus angustifolia trees of all age classes. The aim of this work was to elucidate aspects of the reproduction biology of this fungal pathogen and its cryptic, non-pathogenic sister species Hymenoscyphus albidus. The mating type (MAT) locus of both species was identified, partly sequenced and characterized. Whereas a heterothallic MAT organization was detected in H. pseudoalbidus, H. albidus was shown to be structurally homothallic. The molecular MAT determination of H. pseudoalbidus was confirmed by crossing experiments on sterile ash petioles. Crossings of strains exhibiting alternate MAT idiomorphs produced fertile apothecia whereas crosses of strains with identical MAT idiomorphs were never successful. Offspring genotyping with microsatellites (MSs) and the MAT marker confirmed that both parental strains were involved in apothecia formation. In addition, polymorphic MS were shown to follow Mendelian inheritance. However, for yet unknown reasons the MAT ratio of progenies of one successful cross revealed a significant segregation distortion. Based on the MAT sequences of H. pseudoalbidus a multiplex PCR was developed, allowing for a quick and reliable MAT determination. The PCR was applied to screen the MAT ratio of two H. pseudoalbidus populations derived from the country of the disease outbreak in Poland and two populations from the disease periphery in Switzerland. None of the screened populations showed a significant deviation from the 1:1 ratio, expected under random mating. Therefore, an initial clonal distribution through asexually produced conidiospores as observed for other fungal pathogens holds not true for H. pseudoalbidus. Instead, our data is highly supportive for a distribution through ascospores. Leaf petioles collected in the field were thoroughly analyzed for the number of different colonizing strains and their mating behavior. Up to eight different H. pseudoalbidus genotypes were found on a single petiole. Cross-fertilizations of strains on the same petiole and fertilizations of unknown strains from outside were found, indicating that fertilization is mediated by spermatia. The presented study complements our understanding of the life cycle of this highly destructive pathogen. The possibility to perform sexual crosses in the lab provides ample opportunities for further genetic studies of H. pseudoalbidus and related species in the future. PMID:23036580

Gross, A; Zaffarano, P L; Duo, A; Grnig, C R

2012-12-01

280

A dwarf mouse model with decreased GH/IGF-1 activity that does not experience life-span extension: potential impact of increased adiposity, leptin, and insulin with advancing age.  

PubMed

Reduced growth hormone (GH) action is associated with extended longevity in many vertebrate species. GH receptor (GHR) null (GHR(-)(/-)) mice, which have a disruption in the GHR gene, are a well-studied example of mice that are insulin sensitive and long lived yet obese. However, unlike other mouse lines with reduced GH action, GH receptor antagonist (GHA) transgenic mice have reduced GH action yet exhibit a normal, not extended, life span. Understanding why GHA mice do not have extended life span though they share many physiological attributes with GHR(-)(/-) mice will help provide clues about how GH influences aging. For this study, we examined age- and sex-related changes in body composition, glucose homeostasis, circulating adipokines, and tissue weights in GHA mice and littermate controls. Compared with previous studies with GHR(-)(/-) mice, GHA mice had more significant increases in fat mass with advancing age. The increased obesity resulted in significant adipokine changes. Euglycemia was maintained in GHA mice; however, hyperinsulinemia developed in older male GHA mice. Overall, GHA mice experience a more substantial, generalized obesity accompanied by altered adipokine levels and glucose homeostasis than GHR(-)(/-) mice, which becomes more exaggerated with advancing age and which likely contributes to the lack of life-span extension in these mice. PMID:23695394

Berryman, Darlene E; Lubbers, Ellen R; Magon, Vishakha; List, Edward O; Kopchick, John J

2014-02-01

281

The perfume of reproduction in birds: Chemosignaling in avian social life.  

PubMed

This article is part of a Special Issue ("Chemosignals and Reproduction"). Chemical cues were probably the first cues ever used to communicate and are still ubiquitous among living organisms. Birds have long been considered an exception: it was believed that birds were anosmic and relied on their acute visual and acoustic capabilities. Birds are however excellent smellers and use odors in various contexts including food searching, orientation, and also breeding. Successful reproduction in most vertebrates involves the exchange of complex social signals between partners. The first evidence for a role of olfaction in reproductive contexts in birds only dates back to the seventies, when ducks were shown to require a functional sense of smell to express normal sexual behaviors. Nowadays, even if the interest for olfaction in birds has largely increased, the role that bodily odors play in reproduction still remains largely understudied. The few available studies suggest that olfaction is involved in many reproductive stages. Odors have been shown to influence the choice and synchronization of partners, the choice of nest-building material or the care for the eggs and offspring. How this chemical information is translated at the physiological level mostly remains to be described, although available evidence suggests that, as in mammals, key reproductive brain areas like the medial preoptic nucleus are activated by relevant olfactory signals. Olfaction in birds receives increasing attention and novel findings are continuously published, but many exciting discoveries are still ahead of us, and could make birds one of the animal classes with the largest panel of developed senses ever described. PMID:24928570

Caro, Samuel P; Balthazart, Jacques; Bonadonna, Francesco

2014-06-11

282

Seasonal trends in Ceratitis capitata reproductive potential derived from live-caught females in Greece.  

PubMed

Reproductive data of individual insects are extremely hard to collect under natural conditions, thus the study of research questions related to oviposition has not advanced. Patterns of oviposition are often inferred only indirectly, through monitoring of host infestation, whereas the influence of age structure and several other factors on oviposition remains unknown. Using a new approach, in this article, we live-trapped wild Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) females on the Greek island of Chios during two field seasons. For their remaining lifetime, these females were placed individually in small cages and their daily oviposition was monitored. Reproduction rates between cohorts from different collection dates were then compared. The results showed that in the different captive cohorts the average remaining lifetime and reproduction were highly variable within and between seasons. Multivariate regression analysis showed that the month of capture had a significant effect on captive life span, average daily reproduction, and patterns of egg laying. The effect of year was significant on reproduction, but not on captive life span. These differences between sampling periods probably reflect differences in the availability of hosts and other factors that vary during the season and affect age structure and reproduction. Using a non-parametric generalized additive model, we found a statistically significant correlation between the captive life span and the average daily reproduction. These findings and the experimental approach have several important implications. PMID:22791908

Kouloussis, Nikos A; Papadopoulos, Nikos T; Katsoyannos, Byron I; Mller, Hans-Georg; Wang, Jane-Ling; Su, Yu-Ru; Molleman, Freerk; Carey, James R

2011-09-01

283

EFFECTS OF SUSPENDED SOLIDS AND SEDIMENT ON REPRODUCTION AND EARLY LIFE OF WARMWATER FISHES: A REVIEW  

EPA Science Inventory

The review of published literature and research reports revealed limited data for a few warmwater fish species concerning the impacts of suspended solids and sediments on reproductive success. Laboratory and field studies during the 1930-50s examined direct mortality as the resul...

284

Life histories, blood revenge, and reproductive success among the Waorani of Ecuador  

PubMed Central

The Waorani may have the highest rate of homicide of any society known to anthropology. We interviewed 121 Waorani elders of both sexes to obtain genealogical information and recollections of raids in which they and their relatives participated. We also obtained complete raiding histories of 95 warriors. An analysis of the raiding histories, marital trajectories, and reproductive histories of these men reveals that more aggressive warriors have lower indices of reproductive success than their milder brethren. This result contrasts the findings of Chagnon [Chagnon N (1988) Science 239:985992] for the Yanomamo. We suggest that the spacing of revenge raids may be involved in the explanation of why the consequences of aggressiveness differ between these 2 warlike lowland South American peoples. PMID:19433797

Beckerman, Stephen; Erickson, Pamela I.; Yost, James; Regalado, Jhanira; Jaramillo, Lilia; Sparks, Corey; Iromenga, Moises; Long, Kathryn

2009-01-01

285

Reproduction & life I. Reproductive cycles  

E-print Network

­ eggs are laid outside mother's body l Ovoviparity ­ eggs retained in uterus (no placenta) l Viviparity ­ development inside mother (oviducts or uterus) l Derived condition, specializations for embryonic development in uterus (requires internal fertilization) l Developed via gradual increases in the length of time

Dever, Jennifer A.

286

Optimal life histories and food web position: linkages among somatic growth, reproductive investment, and mortality  

Microsoft Academic Search

Life history variation among 60 Ontario populations of lake trout (Salvelinus namaycush), walleye (Sander vitreus), cisco (Coregonus artedii), and yellow perch (Perca flavescens) is presented and interpreted using a biphasic model of individual growth that specifically accounts for the significant shift in energy allocation that accompanies sexual maturity. We show that the constraints imposed on life history variation by the

B. J. Shuter; N. P. Lester; J. LaRose; C. F. Purchase; K. Vascotto; G. Morgan; N. C. Collins; P. A. Abrams

2005-01-01

287

Life expectancy, economic inequality, homicide, and reproductive timing in Chicago neighbourhoods.  

PubMed Central

In comparisons among Chicago neighbourhoods, homicide rates in 1988-93 varied more than 100-fold, while male life expectancy at birth ranged from 54 to 77 years, even with effects of homicide mortality removed. This "cause deleted" life expectancy was highly correlated with homicide rates; a measure of economic inequality added significant additional prediction, whereas median household income did not. Deaths from internal causes (diseases) show similar age patterns, despite different absolute levels, in the best and worst neighbourhoods, whereas deaths from external causes (homicide, accident, suicide) do not. As life expectancy declines across neighbourhoods, women reproduce earlier; by age 30, however, neighbourhood no longer affects age specific fertility. These results support the hypothesis that life expectancy itself may be a psychologically salient determinant of risk taking and the timing of life transitions. PMID:9154035

Wilson, M.; Daly, M.

1997-01-01

288

Life expectancy, economic inequality, homicide, and reproductive timing in Chicago neighbourhoods.  

PubMed

In comparisons among Chicago neighbourhoods, homicide rates in 1988-93 varied more than 100-fold, while male life expectancy at birth ranged from 54 to 77 years, even with effects of homicide mortality removed. This "cause deleted" life expectancy was highly correlated with homicide rates; a measure of economic inequality added significant additional prediction, whereas median household income did not. Deaths from internal causes (diseases) show similar age patterns, despite different absolute levels, in the best and worst neighbourhoods, whereas deaths from external causes (homicide, accident, suicide) do not. As life expectancy declines across neighbourhoods, women reproduce earlier; by age 30, however, neighbourhood no longer affects age specific fertility. These results support the hypothesis that life expectancy itself may be a psychologically salient determinant of risk taking and the timing of life transitions. PMID:9154035

Wilson, M; Daly, M

1997-04-26

289

View of central lift span truss web of Tensaw River ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

View of central lift span truss web of Tensaw River Bridge, showing support girders for life house, looking east - Tensaw River Lift Bridge, Spanning Tensaw River at U.S. Highway 90, Mobile, Mobile County, AL

290

Covariation in life-history traits: differential effects of diet on condition, hormones, behavior, and reproduction in genetic finch morphs.  

PubMed

The relative contribution of genetic and environmental factors in determining variation in life-history traits is of central interest to evolutionary biologists, but the physiological mechanisms underlying these traits are still poorly understood. Here we experimentally demonstrate opposing effects of nutritional stress on immune function, endocrine physiology, parental care, and reproduction between red and black head-color morphs of the Gouldian finch (Erythrura gouldiae). Although the body condition of black morphs was largely unaffected by diet manipulation, red birds were highly sensitive to dietary changes, exhibiting considerable within-individual changes in condition and immune function. Consequently, nutritionally stressed red birds delayed breeding, produced smaller broods, and reared fewer and lower-quality foster offspring than black morphs. Differences in offspring quality were largely due to morph-specific differences in parental effort: red morphs reduced parental provisioning, whereas black morphs adaptively elevated their provisioning effort to meet the increased nutritional demands of their foster brood. Nutritionally stressed genetic morphs also exhibited divergent glucocorticoid responses. Black morphs showed reduced corticosterone-binding globulin (CBG) concentrations and increased levels of free corticosterone, whereas red morphs exhibited reduced free corticosterone levels and elevated CBG concentrations. These opposing glucocorticoid responses highlight intrinsic differences in endocrine sensitivities and plasticity between genetic morphs, which may underlie the morph-specific differences in condition, behavior, and reproduction and thus ultimately contribute to the evolution and maintenance of color polymorphism. PMID:22322225

Pryke, Sarah R; Astheimer, Lee B; Griffith, Simon C; Buttemer, William A

2012-03-01

291

Reproductive success in presenescent common gulls (Larus canus): the importance of the last year of life.  

PubMed Central

Survival selection against individuals of inferior quality (measured as breeding success) has been proposed to account for the increase in average reproductive success with advancing age in presenescent birds. This so-called selection hypothesis relies on quality-dependent survival. In the present breeding performance study of common gulls, Larus canus, this assumption was not verified. In particular, omitting the last breeding year from the analysis resulted in the disappearance of the correlation between breeding success and survival. A positive correlation in the full dataset was thus solely based on the poor breeding success of ultimate breeders. Indeed, presenescent individuals were shown to have a specifically low breeding success in their terminal breeding event. The poor success of ultimate breeders thus reflects an abruptly declined condition rather than the birds' overall quality. A comparison of the survival of poor and good performers, involving last-time breeders, thus needs not to be a proper test of the selection hypothesis. Longitudinal analysis revealed a steady increase of individual breeding success until the tenth breeding year. The results suggest that an increase of breeding success with age often found in cross-sectional analyses is primarily a result of age-related improvements of competence and/or increased reproductive effort. PMID:15451696

Rattiste, Kalev

2004-01-01

292

Reproductive success in presenescent common gulls (Larus canus): the importance of the last year of life.  

PubMed

Survival selection against individuals of inferior quality (measured as breeding success) has been proposed to account for the increase in average reproductive success with advancing age in presenescent birds. This so-called selection hypothesis relies on quality-dependent survival. In the present breeding performance study of common gulls, Larus canus, this assumption was not verified. In particular, omitting the last breeding year from the analysis resulted in the disappearance of the correlation between breeding success and survival. A positive correlation in the full dataset was thus solely based on the poor breeding success of ultimate breeders. Indeed, presenescent individuals were shown to have a specifically low breeding success in their terminal breeding event. The poor success of ultimate breeders thus reflects an abruptly declined condition rather than the birds' overall quality. A comparison of the survival of poor and good performers, involving last-time breeders, thus needs not to be a proper test of the selection hypothesis. Longitudinal analysis revealed a steady increase of individual breeding success until the tenth breeding year. The results suggest that an increase of breeding success with age often found in cross-sectional analyses is primarily a result of age-related improvements of competence and/or increased reproductive effort. PMID:15451696

Rattiste, Kalev

2004-10-01

293

Temporal variability in the life history and reproductive biology of female dugongs in Torres Strait: The likely role of sea grass dieback  

E-print Network

Strait: The likely role of sea grass dieback Helene Marsh a,b,?, Donna Kwan a,b a School of Environmental in revised form 18 August 2007 Accepted 10 March 2008 Available online 3 April 2008 Keywords: Sea grass Life history Reproduction Dugong and turtle fisheries Torres Strait a b s t r a c t The extensive sea grass

Marsh, Helene

294

Fungal plant endosymbionts alter life history and reproductive success of aphid predators.  

PubMed

Endosymbionts occur in most plant species and may affect interactions among herbivores and their predators through the production of toxic alkaloids. Here, we ask whether effects of mycotoxins produced by the symbiosis of the fungal endophyte Neotyphodium lolii and the grass Lolium perenne are transmitted to the aphidophagous ladybird Coccinella septempunctata when feeding on cereal aphids Rhopalosiphum padi on infected plants. The larval development of coccinellids was extended, while their survival was reduced when feeding exclusively on aphids from infected plants. Ladybirds developing on aphids from infected plants showed reduced fecundity and impaired reproductive performance. Body size and symmetries of ladybird adults were not affected by the endophytes. Consistently strong, negative effects of endophytes on the lifetime performance of ladybirds indicates that mycotoxins are transmitted along food chains, causing significant damage for top predators. Such cascading effects will influence the population dynamics of aphid predators in the long term and could feedback to the primary plant producers. PMID:16720406

de Sassi, Claudio; Mller, Christine B; Krauss, Jochen

2006-05-22

295

Male personality, life-history strategies and reproductive success in a promiscuous mammal  

E-print Network

L O G Y 1599 Keywords: bighorn sheep; boldness; docility; heritability; longevity; Ovis canadensis-term pedigree we estimated indices of boldness and docility for 105 bighorn sheep rams (Ovis canadensis), born personality traits and life-history strategies. Here we use a long-term study of bighorn sheep (Ovis

Festa-Bianchet, Marco

296

Multiple paternity, male reproductive success, hormonal regulation of fertility, and the evolution of life-histories  

Microsoft Academic Search

The life-history strategy that an individual exhibits is shaped by trade-offs between maximizing the number of viable offspring it produces and retaining enough resources to ensure its own survival. The balance between these two aspects is strongly influenced by the environmental conditions the individual experiences in its lifetime and can be affected by the effort an individual puts into each

Megan Brianne Manes

2011-01-01

297

Japan turns pro-life: recent change in reproductive health policy and challenges by new technologies  

PubMed Central

Japan, known as a pro-choice country in terms of abortion, is currently facing the increase of selective abortions thanks to new prenatal screening. Efforts to restrict proliferation of new technology has not been successful and it is likely that Japan will turn pro-life by strictly enforcing the Maternity Protection Act (MPA), which prohibits abortions due to fetal cause. PMID:24639978

Okamoto, Etsuji

2014-01-01

298

Influences of light-dark shifting on the immune system, tumor growth and life span of rats, mice and fruit flies as well as on the counteraction of melatonin.  

PubMed

Animal models were designed to study the changes in immune function, oncogenicity and life span of rats, mice and fruit flies following light-dark (LD) shift manipulations. Alternating the photoperiod of LD 14:10 and DL 10:14 every 3 days in rats disrupted the circadian immune rhythm pattern, decreased the blood leukocyte concentration by 48% and lowered the percentage of lymphocytes in the blood from 71% (control) to 49.2%. In mice, the phagocytosis of neutrophils was only reduced by 7%, but the level of serum hemolysin dropped significantly in the photoperiod-shifted group as compared with animals kept under a constant photoperiod of LD 12:12 or LD 14:10. In Ehrlich-carcinoma- or sarcoma-180-injected mice, a reduction of survival duration, acceleration of tumor growth and depression of the immune system were recorded in the LD-shifted animals. In addition, the life span of fruit flies was shortened by 9.6% by photoperiodic shifting. Melatonin treatment evidently counteracted the deleterious influences of photoperiodic shifting in the above animals. It is suggested that repeated inversion of the LD cycle results in a chronobiological abnormality that, in turn, induces dysfunctions. Reentrainment by exogenous melatonin may inhibit the harmful influences of photoperiodic shifting. PMID:9266095

Li, J C; Xu, F

1997-01-01

299

Insulin-like growth factor-I extends in vitro replicative life span of skeletal muscle satellite cells by enhancing G1/S cell cycle progression via the activation of phosphatidylinositol 3'-kinase/Akt signaling pathway  

NASA Technical Reports Server (NTRS)

Interest is growing in methods to extend replicative life span of non-immortalized stem cells. Using the insulin-like growth factor I (IGF-I) transgenic mouse in which the IGF-I transgene is expressed during skeletal muscle development and maturation prior to isolation and during culture of satellite cells (the myogenic stem cells of mature skeletal muscle fibers) as a model system, we elucidated the underlying molecular mechanisms of IGF-I-mediated enhancement of proliferative potential of these cells. Satellite cells from IGF-I transgenic muscles achieved at least five additional population doublings above the maximum that was attained by wild type satellite cells. This IGF-I-induced increase in proliferative potential was mediated via activation of the phosphatidylinositol 3'-kinase/Akt pathway, independent of mitogen-activated protein kinase activity, facilitating G(1)/S cell cycle progression via a down-regulation of p27(Kip1). Adenovirally mediated ectopic overexpression of p27(Kip1) in exponentially growing IGF-I transgenic satellite cells reversed the increase in cyclin E-cdk2 kinase activity, pRb phosphorylation, and cyclin A protein abundance, thereby implicating an important role for p27(Kip1) in promoting satellite cell senescence. These observations provide a more complete dissection of molecular events by which increased local expression of a growth factor in mature skeletal muscle fibers extends replicative life span of primary stem cells than previously known.

Chakravarthy, M. V.; Abraha, T. W.; Schwartz, R. J.; Fiorotto, M. L.; Booth, F. W.

2000-01-01

300

Communicating Employability Enhancement throughout the Life-Span: A National Intervention Program Aimed at Combating Age-Related Stereotypes at the Workplace  

ERIC Educational Resources Information Center

The stimulation of lifelong employability of employees is one of today's challenges in all sectors of the Dutch society. In this article, we will outline the historical context of the life-long employability issue in the Netherlands, and provide an overview of current business responses to the issue. We will discuss key obstacles for improving

van Selm, Martine; Van der Heijden, Beatrice I. J. M.

2013-01-01

301

The structure of a thermophilic archaeal virus shows a double-stranded DNA viral capsid type that spans all domains of life  

PubMed Central

Of the three domains of life (Eukarya, Bacteria, and Archaea), the least understood is Archaea and its associated viruses. Many Archaea are extremophiles, with species that are capable of growth at some of the highest temperatures and extremes of pH of all known organisms. Phylogenetic rRNA-encoding DNA analysis places many of the hyperthermophilic Archaea (species with an optimum growth ?80C) at the base of the universal tree of life, suggesting that thermophiles were among the first forms of life on earth. Very few viruses have been identified from Archaea as compared to Bacteria and Eukarya. We report here the structure of a hyperthermophilic virus isolated from an archaeal host found in hot springs in Yellowstone National Park. The sequence of the circular double-stranded DNA viral genome shows that it shares little similarity to other known genes in viruses or other organisms. By comparing the tertiary and quaternary structures of the coat protein of this virus with those of a bacterial and an animal virus, we find conformational relationships among all three, suggesting that some viruses may have a common ancestor that precedes the division into three domains of life >3 billion years ago. PMID:15123802

Rice, George; Tang, Liang; Stedman, Kenneth; Roberto, Francisco; Spuhler, Josh; Gillitzer, Eric; Johnson, John E.; Douglas, Trevor; Young, Mark

2004-01-01

302

Life history of yellow baboons: Physical development, reproductive parameters, and infant mortality  

Microsoft Academic Search

Longitudinal data from a population of yellow baboons,Papio cynocephalus, in the Amboseli National Park, Kenya, provide life history parameter estimates. Females reached menarche at approximately\\u000a four-and-a-half years of age and then cycled for approximately a year before first conception. Postpartum anestrum averaged\\u000a 12 months but ranged from six to 16 months. In cases of still births or infant death during

Jeanne Altmann; Stuart A. Altmann; Glenn Hausfater; Sue Ann McCuskey

1977-01-01

303

Life history of hamadryas baboons: Physical development, infant mortality, reproductive parameters and family relationships  

Microsoft Academic Search

Demographic and life history parameters were estimated for a band of free-ranging hamadryas baboons, observed for 5.5 years\\u000a in Ethiopia. Age-related changes in body weight and dentition were found to be delayed relative to laboratory-reared baboons.\\u000a On the average, females reached menarche at 4.3 years of age and had their first infant at the age of 6.1 years. The mean

H. Sigg; A. Stolba; J.-J. Abegglen; V. Dasser

1982-01-01

304

Reproductive styles and life history variables relative to exploitation and management of Sebastes stocks  

Microsoft Academic Search

SynopsisThe characteristics of lightly and heavily exploited Pacific ocean perch,Sebastes alutus, stocks are evaluated relative to the predictions of life history theory. These long-lived species (50100 year lifespan)\\u000a show limited phenotypic plasticity and have little buffering against the effects of reduced lifespan. Reduced stock abundance\\u000a has generated some compensatory increase in growth rate. Length at first maturity varies only slightly

Bruce M. Leaman

1991-01-01

305

A review of the life history, reproduction and phenology of Gracilaria  

Microsoft Academic Search

The basic life history of the red alga Gracilaria is of the three-phase Polysiphonia type but a number of species show deviations. Plants can bear both gametangia and tetrasporangia, either on separate parts\\u000a of the thallus or on the same. Explanations include the in situ germination of tetraspores (allowing gametophytic thalli to be epiphytic on tetrasporophytes), the coalescence of spores

Christophe Destombe

1995-01-01

306

Geographical variation in reproductive ageing patterns and life-history strategy of a short-lived passerine bird.  

PubMed

We investigated differences in ageing patterns in three measures of breeding performance in populations of barn swallows Hirundo rustica L. from Spain and Denmark differing in breeding latitude and hence migration distance and duration of the breeding season. We found differences in ageing patterns between populations. Generally, young (i.e. yearling) and old females (i.e. ?5years of age) laid their first eggs later and produced smaller clutches than middle-aged females (i.e. 2-4years of age) in both populations. The southernmost population (i.e. Spanish) showing the shorter migratory distance experienced a greater within-individual increase in timing of breeding and clutch size in early life and a greater within-individual decrease in laying date but not in clutch size during senescence compared with the northernmost population (i.e. Danish). We also found that the number of fledglings produced annually was related to the age of the two members of the breeding pairs with pairs composed of young and old females performing less well than breeding pairs composed of middle-aged females. We did not find reproductive senescence for the age of the male while controlling for the age of the female on the number of fledglings produced annually by the breeding pair. Differential survival between individuals did not explain age effects on laying date or annual clutch size in neither population. However, the increase in the number of fledglings produced annually with age was partly explained by the disappearance of poor-quality members of the pairs, mainly poor-quality males. Age-related breeding success (i.e. number of fledglings) was similar for barn swallows from Spain and Denmark. Therefore, the study of ageing patterns and life-history strategies in free-ranging animals from more than a single population can throw new light on life-history theory, population dynamics and evolutionary studies of senescence. PMID:22994532

Balbontn, Javier; Mller, A P; Hermosell, I G; Marzal, A; Reviriego, M; de Lope, F

2012-11-01

307

Oral Exposure to Genistin, the Glycosylated Form of Genistein, during Neonatal Life Adversely Affects the Female Reproductive System  

PubMed Central

Background Developmental exposure to environmental estrogens is associated with adverse consequences later in life. Exposure to genistin (GIN), the glycosylated form of the phytoestrogen genistein (GEN) found in soy products, is of concern because approximately 20% of U.S. infants are fed soy formula. High circulating levels of GEN have been measured in the serum of these infants, indicating that GIN is readily absorbed, hydrolyzed, and circulated. Objectives We investigated whether orally administered GIN is estrogenic in neonatal mice and whether it causes adverse effects on the developing female reproductive tract. Methods Female CD-1 mice were treated on postnatal days 15 with oral GIN (6.25, 12.5, 25, or 37.5 mg/kg/day; GEN-equivalent doses), oral GEN (25, 37.5, or 75 mg/kg/day), or subcutaneous GEN (12.5, 20, or 25 mg/kg/day). Estrogenic activity was measured on day 5 by determining uterine wet weight gain and induction of the estrogen-responsive gene lactoferrin. Vaginal opening, estrous cyclicity, fertility, and morphologic alterations in the ovary/reproductive tract were examined. Results Oral GIN elicited an estrogenic response in the neonatal uterus, whereas the response to oral GEN was much weaker. Oral GIN altered ovarian differentiation (i.e., multioocyte follicles), delayed vaginal opening, caused abnormal estrous cycles, decreased fertility, and delayed parturition. Conclusions Our results support the idea that the dose of the physiologically active compound reaching the target tissue, rather than the administered dose or route, is most important in modeling chemical exposures. This is particularly true with young animals in which phase II metabolism capacity is underdeveloped relative to adults. PMID:20049207

Jefferson, Wendy N.; Doerge, Daniel; Padilla-Banks, Elizabeth; Woodling, Kellie A.; Kissling, Grace E.; Newbold, Retha

2009-01-01

308

The Years of Uncertainty: Eighth Grade Family Life Education.  

ERIC Educational Resources Information Center

The family life sex education unit for eighth graders, "The Years of Uncertainty," consists of a series of daily lesson plans that span a 29-day period of one-hour class sessions. Topics covered are: problem solving, knowledge and attitudes, male and female reproductive systems, conception, pregnancy, birth, birth defects, venereal disease,

Carson, Mary, Ed.; And Others

309

Genetic dissection of late-life fertility in Caenorhabditis elegans.  

PubMed

The large post-reproductive life span reported for the free-living hermaphroditic nematode, Caenorhabditis elegans, which lives for about 10 days after its 5-day period of self-reproduction, seems at odds with evolutionary theory. Species with long post-reproductive life spans such as mammals are sometimes explained by a need for parental care or transfer of information. This does not seem a suitable explanation for C elegans. Previous reports have shown that C elegans can regain fertility when mated after the self-fertile period but did not report the functional limits. Here, we report the functional life span of the C elegans germ line when mating with males. We show that C elegans can regain fertility late in life (significantly later than in previous reports) and that the end of this period corresponds quite well to its 3-week total life span. Genetic analysis reveals that late-life fertility is controlled by conserved pathways involved with aging and dietary restriction. PMID:21622982

Mendenhall, Alexander R; Wu, Deqing; Park, Sang-Kyu; Cypser, James R; Tedesco, Patricia M; Link, Christopher D; Phillips, Patrick C; Johnson, Thomas E

2011-08-01

310

REPRODUCTIVE DEVELOPMENT  

Technology Transfer Automated Retrieval System (TEKTRAN)

Throughout history, humans have celebrated the beauty and fertility of flowering plants. In addition to their aesthetic appeal, flowers contain the reproductive organs of the plant and are therefore essential for sexual propagation of plant life. Our dependence on flowering is illustrated by the die...

311

What Deficits in Sexual and Reproductive Health Knowledge Exist among Women with Cystic Fibrosis? A Systematic Review  

ERIC Educational Resources Information Center

The life span of patients with cystic fibrosis (CF) continues to extend due to advances in treatments and care. The rate of pregnancy for female patients with CF has also continued to rise. The purpose of this study was to systematically review the available literature on female patients with CF and their knowledge of sexual and reproductive

Gage, L. Ashley

2012-01-01

312

Effects of trilostane and fipronil on the reproductive axis in an early life stage of the Japanese medaka (Oryzias latipes).  

PubMed

Given the critical role of the hypothalamic-pituitary-gonadal (HPG) axis, it is conceivable that perturbations at any point along this axis can potentially affect reproduction in fish and other vertebrates. We investigated the effects of a 3?-hydroxysteroid dehydrogenase (3?-HSD) inhibitor, trilostane (TRI), and a gamma-aminobutyric acid (GABA)-receptor antagonist, fipronil (FIP), on the HPG axis using an early life stage of the Japanese medaka. The newly hatched larvae were exposed to TRI (100, 300 and 1000 ?g/L) and FIP (3, 10 and 30 ?g/L), respectively, until 28 days post-hatching. Exposure to TRI decreased the body length in males, whereas FIP inhibited growth in both sexes. The induction of steroidogenesis-regulating genes (including 3?-hsd) in males exposed to TRI, accompanied by increased vtg and er transcription, indicating a compensatory response to the presumed 3?-HSD inhibition. These compensatory responses were not observed in TRI-treated females. Regarding FIP exposure, the GABA blocker resulted in the down-regulation of fshr and lhr. A compensatory up-regulation of steroidogenesis-regulating genes partially explained the elevated transcripts of vtg genes in both males and females after FIP exposure. These results suggest that both the inhibition of 3?-HSD and the antagonism of GABA receptors are relevant modes of endocrine disruption that could impact the normal regulation of the HPG axis. PMID:24777665

Sun, Liwei; Jin, Rong; Peng, Zuhua; Zhou, Qiwei; Qian, Haifeng; Fu, Zhengwei

2014-08-01

313

Terminal Investment: Individual Reproduction of Ant Queens Increases with Age  

PubMed Central

The pattern of age-specific fecundity is a key component of the life history of organisms and shapes their ecology and evolution. In numerous animals, including humans, reproductive performance decreases with age. Here, we demonstrate that some social insect queens exhibit the opposite pattern. Egg laying rates of Cardiocondyla obscurior ant queens increased with age until death, even when the number of workers caring for them was kept constant. Cardiocondyla, and probably also other ants, therefore resemble the few select organisms with similar age-specific reproductive investment, such as corals, sturgeons, or box turtles (e.g., [1]), but they differ in being more short-lived and lacking individual, though not social, indeterminate growth. Furthermore, in contrast to most other organisms, in which average life span declines with increasing reproductive effort, queens with high egg laying rates survived as long as less fecund queens. PMID:22509399

Heinze, Jrgen; Schrempf, Alexandra

2012-01-01

314

Extreme Depletion of PIP3 Accompanies the Increased Life Span and Stress Tolerance of PI3K-null C. elegans Mutants  

PubMed Central

The regulation of animal longevity shows remarkable plasticity, in that a variety of genetic lesions are able to extend lifespan by as much as 10-fold. Such studies have implicated several key signaling pathways that must normally limit longevity, since their disruption prolongs life. Little is known, however, about the proximal effectors of aging on which these pathways are presumed to converge, and to date, no pharmacologic agents even approach the life-extending effects of genetic mutation. In the present study, we have sought to define the downstream consequences of age-1 nonsense mutations, which confer 10-fold life extension to the nematode Caenorhabditis elegans the largest effect documented for any single mutation. Such mutations insert a premature stop codon upstream of the catalytic domain of the AGE-1/p110? subunit of class-I PI3K. As expected, we do not detect class-I PI3K (and based on our sensitivity, it constitutes <14% of wild-type levels), nor do we find any PI3K activity as judged by immunodetection of phosphorylated AKT, which strongly requires PIP3 for activation by upstream kinases, or immunodetection of its product, PIP3. In the latter case, the upper 95%-confidence limit for PIP3 is 1.4% of the wild-type level. We tested a variety of commercially available PI3K inhibitors, as well as three phosphatidylinositol analogs (PIAs) that are most active in inhibiting AKT activation, for effects on longevity and survival of oxidative stress. Of these, GDC-0941, PIA6, and PIA24 (each at 1 or 10??M) extended lifespan by 714%, while PIAs 6, 12, and 24 (at 1 or 10??M) increased survival time in 5?mM peroxide by 1252%. These effects may have been conferred by insulinlike signaling, since a reporter regulated by the DAF-16/FOXO transcription factor, SOD-3::GFP, was stimulated by these PIAs in the same rank order (PIA24?>?PIA6?>?PIA12) as lifespan. A second reporter, PEPCK::GFP, was equally activated (?40%) by all three. PMID:23543623

Bharill, Puneet; Ayyadevara, Srinivas; Alla, Ramani; Shmookler Reis, Robert J.

2013-01-01

315

'The brain is the organ of longevity': Introduction to G. A. Sacher's free-energy hypothesis of life-span enhancement  

SciTech Connect

No experiment reported to date constitutes an adequate test in the sense of supplying comprehensive information on survival time, metabolic rate, food consumption and utilization, body mass, anatomical integrity (especially that of the skeletal and nervous systems), status of the immune and endocrine systems, and physiological and behavioral competence in the wake of chronic exposure to a moderately thermalizing radio field. Some reports do provide data on one or more of the important end points, usually in association with a single exposure or a limited number of brief exposures. One must distinguish between prolongation of life in senescence and enhancement of longevity based on actual retardation of the rate of aging. More, retardation of aging, if sorely taxed at the expense of quality of living, is no bargain. Some hibernators live relatively long lives, but the torpor of hibernation--a prolonged period of somnolence and greatly reduced metabolic activity--is hardly the stuff of a vibrant psychological existence.

Justesen, D.R.

1981-10-01

316

Spanning trees of graphs Spanning trees of simplicial complexes  

E-print Network

Spanning trees of graphs Spanning trees of simplicial complexes Color-shifted complexes Weighted spanning tree enumerators of color-shifted complexes Ghodratollah Aalipour1,2 Art Duval1 1University Ghodratollah Aalipour, Art Duval Spanning tree enumerators of color-shifted complexes #12;Spanning trees

Duval, Art

317

Spanning trees of graphs Spanning trees of simplicial complexes  

E-print Network

Spanning trees of graphs Spanning trees of simplicial complexes Complete colorful complexes Weighted spanning tree enumerators of complete colorful complexes Ghodratollah Aalipour1,2 Art Duval1 1 Aalipour, Art Duval Spanning tree enumerators of complete colorful complexes #12;Spanning trees of graphs

Duval, Art

318

Subsequent reproductive outcome in women who have experienced a potentially life-threatening condition or a maternal near-miss during pregnancy  

PubMed Central

OBJECTIVE: To evaluate the long-term reproductive consequences that affect women who have experienced potentially life-threatening or life-threatening (near-miss) maternal complications. INTRODUCTION: Although advances have been made in reducing maternal death, few studies have investigated the long-term repercussions of significant events such as severe maternal morbidity and maternal near-misses. These repercussions may be long-lasting and negatively affect quality of life. METHODS: A total of 382 women who had experienced a potentially life-threatening pregnancy-related condition within the last five years were analyzed in this retrospective cohort study. A control group of 188 women who gave birth without complications was also included. Trained interviewers contacted the subjects by telephone and completed a pre-coded, structured questionnaire on reproductive health. Data were analyzed using odds ratios adjusted for age. The main outcome measures were occurrence and outcome of subsequent pregnancies. RESULTS: The estimated risk of becoming infertile as a result of tubal ligation or hysterectomy was 3.5 times higher in women who experienced a maternal near-miss or severe maternal morbidity during the index pregnancy as compared to controls. Likewise, the risk of complications in subsequent pregnancies was five times greater in women who had experienced severe maternal morbidity. However, no differences were found in the occurrence or number of subsequent pregnancies or perinatal outcome. CONCLUSION: The occurrence of a life-threatening or potentially life-threatening maternal condition reduces future reproductive potential and increases the risk of complications in subsequent pregnancies. PMID:21915485

Camargo, Rodrigo S.; Pacagnella, Rodolfo C.; Cecatti, Jos G.; Parpinelli, Mary A.; Souza, Joo P.; Sousa, Maria H.

2011-01-01

319

Reproduction, survival, and life table parameters of the predatory mite Cheyletus malaccensis (Acari: Cheyletidae) at various constant temperatures.  

PubMed

Reproduction, survival, and life table parameters of the predatory mite Cheyletus malaccensis Oudemans were evaluated at six constant temperatures: 17.5, 20, 25, 30, 32.5 and 35C, feeding on Tyrophagus putrescentiae (Schrank). Preoviposition period of fertilized and virgin females varied with temperature from ca. 9 days at 17.5C to ca. 1.5 day at 32.5C and then increased to ca. 3 days at 35C. Virgin female oviposition period was significantly shorter than for fertilized females at the temperatures examined with the exception of 17.5C. The mean total number of eggs per fertilized (169.7 6.6) and virgin female (60.7 4.3) was highest at the temperature of 30C. The data indicated a significant positive and nearly doubling effect of fertilization on female fecundity at the temperatures examined with the exception of 17.5C. Age-specific fecundity was described by a temperature dependent model from which the maximum daily fecundity rate was estimated for fertilized and virgin females at 10.3 (at 30C) and 6.8 (at 32.5C) eggs/female, respectively. Virgin female longevity was significantly shorter than for fertilized females at 20, 30 and 32.5C, and decreased from ca. 57 days at 17.5C to ca. 17 days at 35C. The Weibull function that was used to describe the age specific survival of fertilized and virgin females produced excellent fits to the survival data. Estimates of intrinsic rate of increase, net reproductive rate, mean generation time, doubling time and finite rate of increase, were obtained. The r(m) value increased with temperature from 0.03 (day(-1)) at 17.5C to 0.21 (day(-1)) at 32.5C, after which it decreased to 0.15 (day(-1)) at 35C. These data indicate that C. malaccensis can reproduce at temperatures between 17.5 and 35C and can be used for biological control of astigmatid mites within the temperature range where the pest occurs. PMID:21287248

Palyvos, Nickolas E; Emmanouel, Nickolas G

2011-06-01

320

The effects of Chilomonas on the life history traits of [-2pt] Daphnia longispina under semi-natural conditions and the implications for competition in the plankton  

Microsoft Academic Search

Assuming that heterotrophic flagellates (H.F.) can sustain cladoceran life cycles, particularly at periods of low food and high detritus conditions, the growth, reproduction and life span of Daphnia longispinawere studied under conditions of summer food limitation. They were fed both natural resources and natural food enriched with a culture of the colourless Chilomonas (ovoid cell, 8 25 m). Four

Nicole Lair; Virginie Picard

2000-01-01

321

Tracking bacterial growth in liquid media and a new bacterial life model  

Microsoft Academic Search

By increasing viscosity of liquid media above 8.4 centipoise (cp) i.e. 0.084 g cm-1 s-1, individual growth and family formation ofEscherichia coli was continuously observed in real-time for up to 6 h. The observations showed primarily unidirectional growth and reproduction\\u000a ofE. coli and suggested more than one reproduction in the observed portion ofE. coli life span. A new bacterial

Shi Liu

1999-01-01

322

Spanning trees of graphs Spanning trees of simplicial complexes  

E-print Network

Spanning trees of graphs Spanning trees of simplicial complexes Complete colorful complexes Weighted spanning tree enumerators of complete colorful complexes Ghodratollah Aalipour1,2 Art Duval1 1 April 21, 2013 Ghodratollah Aalipour, Art Duval Spanning tree enumerators of complete colorful complexes

Duval, Art

323

Spanning trees of graphs Spanning trees of simplicial complexes  

E-print Network

Spanning trees of graphs Spanning trees of simplicial complexes Complete colorful complexes Weighted spanning tree enumerators of complete colorful complexes Ghodratollah Aalipour1,2 Art Duval1 1 of Mississippi March 2, 2013 Ghodratollah Aalipour, Art Duval Spanning tree enumerators of complete colorful

Duval, Art

324

Spanning trees of graphs Spanning trees of simplicial complexes  

E-print Network

Spanning trees of graphs Spanning trees of simplicial complexes Critical group of graphs Critical group of simplicial complexes Spanning trees and the critical group of simplicial complexes Art Duval1 Mathematics Colloquium New Mexico State University October 20, 2011 Duval, Klivans, Martin Spanning trees

Duval, Art

325

Spanning trees of graphs Spanning trees of simplicial complexes  

E-print Network

Spanning trees of graphs Spanning trees of simplicial complexes Critical group of graphs Critical group of simplicial complexes Spanning trees and the critical group of simplicial complexes Art Duval1 of Kansas Mathematics Seminar Reed College April 28, 2011 Duval, Klivans, Martin Spanning trees

Duval, Art

326

Spanning trees of graphs Spanning trees of simplicial complexes  

E-print Network

Spanning trees of graphs Spanning trees of simplicial complexes Color-shifted complexes Weighted spanning tree enumerators of color-shifted complexes Ghodratollah Aalipour1,2 Art Duval1 1University in St. Louis October 20, 2013 Ghodratollah Aalipour, Art Duval Spanning tree enumerators of color

Duval, Art

327

Spanning trees of graphs Spanning trees of simplicial complexes  

E-print Network

Spanning trees of graphs Spanning trees of simplicial complexes Critical group of graphs Critical group of simplicial complexes Spanning trees and the critical group of simplicial complexes Art Duval1 of Kansas Discrete CATS seminar University of Kentucky March 30, 2011 Duval, Klivans, Martin Spanning trees

Duval, Art

328

5. VIEW OF SPAN ADJOINING SPAN TO THE NORTH OF ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. VIEW OF SPAN ADJOINING SPAN TO THE NORTH OF THE VERTICAL LIFT SPAN (IN THE DISTANCE IS THE RECENTLY COMPLETED NEW STATE ROUTE 51 BRIDGE CROSSING THE ILLINOIS RIVER). - Shippingsport Bridge, Spanning Illinois River at State Route 51, La Salle, La Salle County, IL

329

An evaluation of fish early life stage tests for predicting reproductive and longer-term toxicity from plant protection product active substances.  

PubMed

The chronic toxicity of chemicals to fish is routinely assessed by using fish early life stage (ELS) test results. Fish full life cycle (FLC) tests are generally required only when toxicity, bioaccumulation, and persistence triggers are met or when there is a suspicion of potential endocrine-disrupting properties. This regulatory approach is based on a relationship between the results of fish ELS and FLC studies first established more than 35 yrs ago. Recently, this relationship has been challenged by some regulatory authorities, and it has been recommended that more substances should undergo FLC testing. In addition, a project proposal has been submitted to the Organisation for Economic Cooperation and Development (OECD) to develop a fish partial life cycle (PLC) test including a reproductive assessment. Both FLC and PLC tests are animal- and resource-intensive and technically challenging and should therefore be undertaken only if there is clear evidence that they are necessary for coming to a regulatory decision. The present study reports on an analysis of a database of paired fish ELS and FLC endpoints for plant protection product active substances from European Union draft assessment reports and the US Environmental Protection Agency Office of Pesticide Programs Pesticide Ecotoxicity Database. Analysis of this database shows a clear relationship between ELS and FLC responses, with similar median sensitivity across substances when no-observed-effect concentrations (NOECs) are compared. There was also no indication that classification of a substance as a mammalian reproductive toxicant leads to more sensitive effects in fish FLC tests than in ELS tests. Indeed, the response of the ELS tests was generally more sensitive than the most sensitive reproduction NOEC from a FLC test. This analysis indicates that current testing strategies and guidelines are fit for purpose and that there is no need for fish full or partial life cycle tests for most plant protection product active substances. PMID:24799351

Wheeler, James R; Maynard, Samuel K; Crane, Mark

2014-08-01

330

Reproductive System  

Microsoft Academic Search

\\u000a Reproduction differs from other physiological functions in the sense that it is not essential for survival of an individual,\\u000a only for that of the species. However, the prevalence of infertility is on the rise, and it seriously affects the quality\\u000a of life of the couples affected. Since both contraception and infertility problems concern young, otherwise healthy individuals,\\u000a the possibilities to

M. Poutanen; F.-P. Zhang; S. Rulli; S. Mkel; P. Sipil; J. Toppari; I. Huhtaniemi

331

Cellular life span and the Warburg effect  

Microsoft Academic Search

Enhanced glycolysis is observed in most of cancerous cells and tissues, called as the Warburg effect. Recent advance in senescent biology implicates that the metabolic shift to enhanced glycolysis would be involved in the early stage during multi-step tumorigenesis in vivo. Enhanced glycolysis is essential both in the step of immortalization and transformation, as it renders cells resistant to oxidative

Hiroshi Kondoh

2008-01-01

332

Touch Therapies across the Life Span  

Microsoft Academic Search

The Ayur-Veda, the earliest known medical text from India (around 1800 b.c.), lists touch therapy (massage therapy), diet, and exercise as primary healing practices of that time. As Jules Older notes,\\u000a even the English word shampoo comes from the word champna, which is an ancient Indian word meaning to press (Older, 1982). From early times, massage has been effectively used

Tiffany M. Field

333

Autobiographical Memory from a Life Span Perspective  

ERIC Educational Resources Information Center

This comparative study (i.e., three age groups, three measures) explores the distribution of retrospective and prospective autobiographical memory data across the lifespan, in particular the bump pattern of disproportionally higher recall of memories from the ages 10 to 30, as generally observed in older age groups, in conjunction with the

Schroots, Johannes J. F.; van Dijkum, Cor; Assink, Marian H. J.

2004-01-01

334

Embodied learning across the life span.  

PubMed

Developmental psychologists have long recognized the extraordinary influence of action on learning (Held & Hein, 1963; Piaget, 1952). Action experiences begin to shape our perception of the world during infancy (e.g., as infants gain an understanding of others' goal-directed actions; Woodward, 2009) and these effects persist into adulthood (e.g., as adults learn about complex concepts in the physical sciences; Kontra, Lyons, Fischer, & Beilock, 2012). Theories of embodied cognition provide a structure within which we can investigate the mechanisms underlying action's impact on thinking and reasoning. We argue that theories of embodiment can shed light on the role of action experience in early learning contexts, and further that these theories hold promise for using action to scaffold learning in more formal educational settings later in development. PMID:22961943

Kontra, Carly; Goldin-Meadow, Susan; Beilock, Sian L

2012-10-01

335

Mental Health Disorders May Shorten Life Span  

MedlinePLUS

... earlier death, it wasn't designed to prove that the disorders were a direct cause of the early deaths. When people think of ... lack of exercise, trouble sticking with medications, or problems getting the health care they need. Olfson agreed, noting that physical health issues like obesity and type 2 ...

336

C-SPAN Classroom  

NSDL National Science Digital Library

The C-SPAN in the classroom website is geared toward teachers of political science - or specifically U.S. Government. The site is split into six segments: Principles of Government, the Constitution, Political Participation and each of the three branches of government. Each of these sections features video clips, and questions for class discussion. Free site membership is available, but not required to use the site. Some additional content and services are available with membership.

337

Span efficiency in hawkmoths  

PubMed Central

Flight in animals is the result of aerodynamic forces generated as flight muscles drive the wings through air. Aerial performance is therefore limited by the efficiency with which momentum is imparted to the air, a property that can be measured using modern techniques. We measured the induced flow fields around six hawkmoth species flying tethered in a wind tunnel to assess span efficiency, ei, and from these measurements, determined the morphological and kinematic characters that predict efficient flight. The species were selected to represent a range in wingspan from 40 to 110 mm (2.75 times) and in mass from 0.2 to 1.5 g (7.5 times) but they were similar in their overall shape and their ecology. From high spatio-temporal resolution quantitative wake images, we extracted time-resolved downwash distributions behind the hawkmoths, calculating instantaneous values of ei throughout the wingbeat cycle as well as multi-wingbeat averages. Span efficiency correlated positively with normalized lift and negatively with advance ratio. Average span efficiencies for the moths ranged from 0.31 to 0.60 showing that the standard generic value of 0.83 used in previous studies of animal flight is not a suitable approximation of aerodynamic performance in insects. PMID:23658113

Henningsson, Per; Bomphrey, Richard J.

2013-01-01

338

Toxicity of copper-spiked sediments to Tubifex tubifex (Oligochaeta, Tubificidae): Comparison of the 28-day reproductive bioassay with an early-life-stage bioassay  

SciTech Connect

Two sediment bioassay methods using Tubifex tubifex (Mueller, 1774) as the test species were compared. The first was an adult reproduction test, the second an early-life-stage survival test. The duration of both bioassays is 28 d and the amount of work required was similar; they may be useful alternatives to each other in different circumstances (e.g., the early life stage bioassay could be carried out with smaller volumes of sediment). The two bioassays were performed simultaneously on copper-spiked sediments. Sediments from two freshwater and two terrestrial sites were used; five separate, nonsimultaneous experiments were performed, one for each sediment or soil and a further experiment with soil with a good supplement. In the adult bioassay, there were large differences in the production of cocoons, eggs, and young among the control treatments of the five experiments. There were also major differences in the NOEC and LOEC for copper between the tested substrates. The early life stage bioassay appears to be less sensitive to copper toxicity than the adult reproductive bioassay since NOECs and LOECs are higher for early survival than for the most sensitive endpoints of the adult bioassay in three experiments out of five.

Vecchi, M.; Pasteris, A.; Bonomi, G. (Univ. degli Studi di Bologna (Italy). Dipt. di Biologia Evoluzionistica Sperimentale); Reynoldson, T.B. (Environment Canada, Burlington, Ontario (Canada). National Water Research Inst.)

1999-06-01

339

Characteristics of an infinite life span diploid human fibroblast cell strain and a near-diploid strain arising from a clone of cells expressing a transfected v-myc oncogene  

SciTech Connect

Diploid human fibroblasts were transfected with a plasmid carrying a v-myc oncogene linked to the neo gene or with a vector control carrying a neo gene. Drug-resistant clones were isolated and subcultured as needed. All populations went into crisis and eventually senesced. But while they were senescing, viable-appearing clones were noted among the progeny of a transfected population that expressed the v-myc oncogene. After several months, these cells began replicating more rapidly. Karyotype analysis indicated that they were clonally derived since all of them had 45 chromosomes, including 2 marker chromosomes. This cell strain was designated MSU-1.1. Similar analysis showed that cells from an earlier passage were diploid. These cells were designated MSU-1.0. The expression of v-myc is probably required for acquisition of an infinite life span, since this phenotype did not develop in populations not expressing this oncogene. However, expression of v-myc is clearly not sufficient, since all of the progeny of the clone that gave rise to the MSU-1.0 cells expressed this oncogene, but the vast majority of them senesced.

Morgan, T.L.; Dajun Yang; Fry, D.G.; Hurlin, P.J.; Kohler, S.K.; Maher, V.M.; McCormick, J.J. (Michigan State Univ., East Lansing (United States))

1991-11-01

340

Over-expression of the catalytic core of mitochondrial DNA (mtDNA) polymerase in the nervous system of Drosophila melanogaster reduces median life span by inducing mtDNA depletion.  

PubMed

DNA polymerase gamma (pol gamma) is the sole DNA polymerase devoted to mitochondrial DNA (mtDNA) replication. We have characterized the molecular and physiological effects of over-expression of the catalytic subunit of pol gamma, pol gamma-alpha, in the nervous system of Drosophila melanogaster using the upstream activation sequence (UAS)/yeast transcriptional activator by binding to UAS (GAL4) system. Tissue-specific over-expression of pol gamma-alpha was confirmed by immunoblot analysis, whereas the very low levels of endogenous protein are undetectable in UAS or GAL4 control lines. The transgenic flies over-expressing pol gamma-alpha in the nervous system showed a moderate increase in pupal lethality, and a significant decrease in the median life span of adult flies. Moreover, these flies displayed a decrease in the rate of synthesis of mtDNA, which is accompanied by a significant mtDNA depletion, and a corresponding decrease in the levels of mitochondrial transcription factor A (mtTFA). Biochemical analysis showed an oxidative phosphorylation (OXPHOS) defect in transgenic flies, which were more susceptible to oxidative stress. Although we did not detect apoptosis in the nervous system of adult transgenic flies, brains of larvae over-expressing pol gamma-alpha showed evidence of increased cell death that correlates with the observed phenotypes. Our data establish an animal model that mimics some of the features of human mtDNA depletion syndromes. PMID:17999718

Martnez-Azorn, Francisco; Calleja, Manuel; Hernndez-Sierra, Rosana; Farr, Carol L; Kaguni, Laurie S; Garesse, Rafael

2008-04-01

341

Oosorption in response to poor food: complexity in the trade-off between reproduction and survival.  

PubMed

Plasticity in reproductive physiology is one avenue by which environmental signals, such as poor quality food, can be coordinated with adaptive responses. Insects have the ability to resorb oocytes that are not oviposited. Oosorption is proposed to be an adaptive mechanism to optimize fitness in hostile environments, recouping resources that might otherwise be lost, and reinvesting them into future reproductive potential. We tested the hypothesis that oosorption is an evolved mechanism by which females can reallocate resources from current reproductive effort to survival and future reproduction, when conditions for reproduction are poor, by examining the reproductive physiology and life-history outcome under poor quality food in populations of the milkweed bug (Oncopeltus fasciatus) that have adapted to live on sunflower seed. Females fed a diet of pumpkin seeds, known to be a poor host food, had higher levels of ovarian apoptosis (oosorption), lower reproductive output, but no reduction in life span under poor nutrition, as predicted under the oosorption hypothesis. However, the schedule of reproduction was surprising given the "wait to reproduce" assumption of oosorption as early fecundity was unaffected. PMID:22393481

Moore, Patricia J; Attisano, Alfredo

2011-09-01

342

56. VIEW SOUTH, WEST SIDE AT CANTILEVER SPAN (SPAN 70) ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

56. VIEW SOUTH, WEST SIDE AT CANTILEVER SPAN (SPAN 70) SHOWING FACADE, DOUBLE CROSS BRACING AT COLUMNS, AND CONCRETE BASE - Route 1 Extension, Southbound Viaduct, Spanning Conrail Yards, Wilson Avenue, Delancy Street, & South Street on Routes 1 & 9 Southbound, Newark, Essex County, NJ

343

Community attitude towards the reproductive rights and sexual life of people living with HIV/AIDS in Olorunda Local Government Area, Osogbo, Nigeria  

PubMed Central

Background Globally, the Human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) epidemic remains a major public health problem. In most countries in sub-Saharan Africa, HIV/AIDS has already reversed the post-independence developmental gains. Purpose This study assessed community attitudes regarding the reproductive rights and sexual life of people living with HIV/AIDS (PLWHA) in Olorunda Local Government Area of Osun State, Southwestern Nigeria. Design and methods In a community-based descriptive cross-sectional study, the sample size calculation was based on the assumption that 67% of the target population has a negative attitude regarding the reproductive rights of PLWHA; a confidence interval (CI) of 95% was used. A minimum sample size of 340 was obtained using the formula n = Z2pq/d2. An anticipated 10% nonresponse rate was added to obtain a sample size of 374; a multistage sampling technique was utilized to select a total of 450 respondents. Data collected through a semistructured standardized and pretested questionnaire were analyzed using Statistical Package for Social Sciences software, version 15. Results The study revealed that 283 (66.6%) and 142 (33.4%) of respondents were urban and rural dwellers, respectively. Mean age of respondents was 28.7 years 2.2 years. Four hundred and two (94.6%) respondents were aware of HIV/AIDS, and 88.7% had knowledge of at least six different modes of HIV/AIDS transmission. About 30.7% of respondents had discriminatory and stigmatizing attitudes towards PLWHA, and 50.9% and 44.8% had negative attitudes towards their sexual and reproductive rights, respectively. There were significant associations between gender, marital status, educational status, occupation, and residential area of respondents and their attitude towards the reproductive and sexual right of PLWHA (P < 0.05). Conclusion and recommendation Discriminatory and stigmatizing attitudes to PLWHA found among respondents translated into a negative attitude regarding the reproductive and sexual rights of PLWHA. There is an urgent need to institute programs for raising community awareness about the rights of PLWHA, especially in rural areas, and to strengthen legislative provisions for protecting and preserving the reproductive rights of PLWHA. PMID:23807862

Asekun-Olarinmoye, EO; Asekun-Olarinmoye, IO; Adebimpe, WO; Olugbenga-Bello, AI

2013-01-01

344

The relationship between tooth wear, habitat quality and late-life reproduction in a wild red deer population  

Microsoft Academic Search

Summary 1. Molar tooth wear is considered an important proximate mechanism driving patterns of senescence in ungulates but few studies have investigated the causes of variation in molar wear or their consequences for reproductive success. 2. In this study, we assessed molar tooth wear at death among red deer Cervus elaphus of known age on the Isle of Rum, Scotland.

DANIEL H. NUSSEY; BONNIE METHERELL; KELLY MOYES; ALISON DONALD; FIONA E. GUINNESS; TIM H. CLUTTON-BROCK

2007-01-01

345

98. Reproduction from glass plate negative (Modjeski and Masters office, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

98. Reproduction from glass plate negative (Modjeski and Masters office, Modjeski Collection, No. 181, May 5, 1908) STEEL ERECTION AT DRAW SPAN - Burlington Northern Railroad Bridge, Spanning Willamette River at River Mile 6.9, Portland, Multnomah County, OR

346

89. Reproduction from glass plate negative (Modjeski and Masters office, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

89. Reproduction from glass plate negative (Modjeski and Masters office, Modjeski Collection, No. 6, not dated) DRAW SPAN - Burlington Northern Railroad Bridge, Spanning Willamette River at River Mile 6.9, Portland, Multnomah County, OR

347

100. Reproduction from glass plate negative (Modjeski and Masters office, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

100. Reproduction from glass plate negative (Modjeski and Masters office, Modjeski Collection, No. 198, July 25, 1908) VIEW OF DRAW SPAN - Burlington Northern Railroad Bridge, Spanning Willamette River at River Mile 6.9, Portland, Multnomah County, OR

348

95. Reproduction from glass plate negative (Modjeski and Masters office, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

95. Reproduction from glass plate negative (Modjeski and Masters office, Modjeski Collection, No. 150, January 18, 1908) SPANS 4 AND 5 - Burlington Northern Railroad Bridge, Spanning Willamette River at River Mile 6.9, Portland, Multnomah County, OR

349

Dynamic Capacitated Minimum Spanning Trees  

Microsoft Academic Search

Given a set of terminals, each associated with a positive number denoting the traffic to be routed to a central terminal (root), the Capacitated Minimum Spanning Tree (CMST) problem asks for a minimum spanning tree, spanning all terminals, such that the amount of traffic route d from a subtree, linked to the root by an edge, does not exceed the

Raja Jothi; Balaji Raghavachari

2004-01-01

350

An empirical test of evolutionary theories for reproductive senescence and reproductive effort in the garter snake Thamnophis elegans  

Microsoft Academic Search

Evolutionary theory predicts that differential reproductive effort and rate of reproductive senescence will evolve under different rates of external mortality. We examine the evolutionary divergence of age-specific reproduction in two life-history ecotypes of the western terrestrial garter snake, Thamnophis elegans. We test for the signature of reproductive senescence (decreasing fecundity with age) and increasing reproductive effort with age (increasing reproductive

Amanda M. Sparkman; Stevan J. Arnold; Anne M. Bronikowski

2007-01-01

351

Estrogenic environmental endocrine-disrupting chemical effects on reproductive neuroendocrine function and dysfunction across the life cycle  

Microsoft Academic Search

Endocrine disrupting chemicals (EDCs) are natural or synthetic compounds that interfere with the normal function of an organisms\\u000a endocrine system. Many EDCs are resistant to biodegradation, due to their structural stability, and persist in the environment.\\u000a The focus of this review is on natural and artificial EDCs that act through estrogenic mechanisms to affect reproductive neuroendocrine\\u000a systems. This endocrine axis

Sarah M. Dickerson; Andrea C. Gore

2007-01-01

352

Costs of reproduction in a long-lived female primate: injury risk and wound healing.  

PubMed

Reproduction is a notoriously costly phase of life, exposing individuals to injury, infectious disease, and energetic tradeoffs. The strength of these costs should be influenced by life history strategies, and in long-lived species, females may be selected to mitigate costs of reproduction because life span is such an important component of their reproductive success. Here we report evidence for two costs of reproduction that may influence survival in wild female baboons-injury risk and delayed wound healing. Based on 29 years of observations in the Amboseli ecosystem, Kenya, we found that wild female baboons experienced the highest risk of injury on days when they were most likely to be ovulating. In addition, lactating females healed from wounds more slowly than pregnant or cycling females, indicating a possible tradeoff between lactation and immune function. We also found variation in injury risk and wound healing with dominance rank and age: older and low-status females were more likely to be injured than younger or high-status females, and older females exhibited slower healing than younger females. Our results support the idea that wild non-human primates experience energetic and immune costs of reproduction, and they help illuminate life history tradeoffs in long-lived species. PMID:25045201

Archie, Elizabeth A; Altmann, Jeanne; Alberts, Susan C

2014-07-01

353

Adult fathead minnow, Pimephales promelas, partial life-cycle reproductive and gonadal histopathology study with bisphenol A.  

PubMed

Bisphenol A (BPA) is an intermediate used to produce epoxy resins and polycarbonate plastics. Although BPA degrades rapidly in the environment with aquatic half-lives from 0.5 to 6 d, it can be found in aquatic systems because of widespread use. To evaluate potential effects from chronic exposure, fathead minnows were exposed for 164 d to nominal concentrations of 1, 16, 64, 160, and 640 g/L BPA. Population-level endpoints of survival, growth, and reproduction were assessed with supplemental endpoints (e.g., vitellogenin, gonad histology), including gonad cell type assessment and quantification. No statistically significant changes in growth, gonad weight, gonadosomatic index, or reproduction variables (e.g., number of eggs and spawns, hatchability) were observed; however, there was a significant impact on male survival at 640 g/L. Vitellogenin increased in both sexes at 64 g/L or higher. Gonad cell type frequencies were significantly different from controls at 160 g/L or higher in males with a slight decrease in spermatocytes compared with less mature cell types, and at 640 g/L in females with a slight decrease in early vitellogenic cells compared with less mature cells. The decrease in spermatocytes did not correspond to a decrease in the most mature sex cell type (spermatozoa) and did not impair male fertility, as hatchability was not impacted. Overall, marginal shifts in gametogenic cell maturation were not associated with any statistically significant effects on population-relevant reproductive endpoints (growth, fecundity, and hatchability) at any concentration tested. PMID:22865792

Mihaich, Ellen; Rhodes, Jon; Wolf, Jeff; van der Hoeven, Nelly; Dietrich, Daniel; Hall, A Tilghman; Caspers, Norbert; Ortego, Lisa; Staples, Charles; Dimond, Steve; Hentges, Steven

2012-11-01

354

Changes in reproductive life-history strategies in response to nest density in a shell-brooding cichlid, Telmatochromis vittatus  

NASA Astrophysics Data System (ADS)

To determine whether the appearance of a reproductively parasitic tactic varies, and how this variation affects territorial males of the Lake Tanganyika cichlid fish Telmatochromis vittatus, we examined the reproductive ecology of territorial males in Mtondwe and compared it with that of a neighboring Wonzye population, where nest density differs from that at Mtondwe. In Wonzye, with high nest density, male tactics change with their body size from a territorial to a non-territorial parasitic tactic called piracy in which they conquer several nests defended by territorial males and take over the nests while females are spawning. These "pirate" males could decrease the costs incurred by travelling among nests by exclusively targeting aggregations of nests in close proximity while avoiding separate nests. Territorial males in Wonzye sacrifice the potential higher attractiveness offered by large nests and instead compete for nests farther from neighbors on which pirates less frequently intrude. In contrast, the Mtondwe population had lower nest density and piracy was absent. Given that the success of piracy depends on the close proximity of nests, nest density is likely responsible for the observed variation in the occurrence of piracy between the two populations. Furthermore, in Mtondwe, territorial males competed for larger nests and were smaller than the territorial males in Wonzye. Thus, this lower nest density may free territorial males from the selection pressures for increased size caused by both defense against nest piracy and the need to develop into pirates as they grow.

Ota, Kazutaka; Hori, Michio; Kohda, Masanori

2012-01-01

355

Changes in reproductive life-history strategies in response to nest density in a shell-brooding cichlid, Telmatochromis vittatus.  

PubMed

To determine whether the appearance of a reproductively parasitic tactic varies, and how this variation affects territorial males of the Lake Tanganyika cichlid fish Telmatochromis vittatus, we examined the reproductive ecology of territorial males in Mtondwe and compared it with that of a neighboring Wonzye population, where nest density differs from that at Mtondwe. In Wonzye, with high nest density, male tactics change with their body size from a territorial to a non-territorial parasitic tactic called piracy in which they conquer several nests defended by territorial males and take over the nests while females are spawning. These "pirate" males could decrease the costs incurred by travelling among nests by exclusively targeting aggregations of nests in close proximity while avoiding separate nests. Territorial males in Wonzye sacrifice the potential higher attractiveness offered by large nests and instead compete for nests farther from neighbors on which pirates less frequently intrude. In contrast, the Mtondwe population had lower nest density and piracy was absent. Given that the success of piracy depends on the close proximity of nests, nest density is likely responsible for the observed variation in the occurrence of piracy between the two populations. Furthermore, in Mtondwe, territorial males competed for larger nests and were smaller than the territorial males in Wonzye. Thus, this lower nest density may free territorial males from the selection pressures for increased size caused by both defense against nest piracy and the need to develop into pirates as they grow. PMID:22089034

Ota, Kazutaka; Hori, Michio; Kohda, Masanori

2012-01-01

356

Reproduction in captive common marmosets (Callithrix jacchus).  

PubMed

Though sexual maturation may begin at around one year of age, first successful reproduction of the common marmoset (Callithrix jacchus) is likely to be later, and it is generally recommended that animals not be mated before 1.5 years of age. The average gestation period is estimated to be 143 to 144 days. A crown-rump length measurement taken by use of ultrasonography during the linear, rapid, prenatal growth phase (between approx. days 60 and 95) can be compared against standard growth curves to estimate delivery date to within 3 to 4 days, on average. Marmosets produce more young per delivery than does any other anthropoid primate, and have more variation in litter size. Many long-established colonies report that triplets are the most common litter size, and there is documented association between higher maternal body weight and higher ovulation numbers. Higher litter sizes generally do not generate higher numbers of viable young. Marmosets are unusual among primates in having a postpartum ovulation that typically results in conception and successful delivery; reported median inter-birth intervals range from 154 to 162 days. However, pregnancy losses are quite common; one study of a large breeding colony indicated 50 percent loss between conception and term delivery. The average life span for breeding females is around six years; the range of reported average lifetime number of litters for a breeding pair is 3.45 to 4.0. Our purpose is to provide an overview of reproduction in the common marmoset, including basic reproductive life history, lactation and weaning, social housing requirements, and common problems encountered in the captive breeding of this species. A brief comparison between marmoset and tamarin reproduction also will be provided. PMID:14524412

Tardif, Suzette D; Smucny, Darlene A; Abbott, David H; Mansfield, Keith; Schultz-Darken, Nancy; Yamamoto, Maria Emilia

2003-08-01

357

Sentencing Juveniles to Life in Prison: The Reproduction of Juvenile Justice for Young Adolescents Charged with Murder  

ERIC Educational Resources Information Center

In "Roper v. Simmons," the U.S. Supreme Court determined that the sentencing of juveniles to death violated the constitutional amendment against cruel and unusual punishment. Similarly, the Court most recently decided that life without parole for non-homicide offenses is also unconstitutional ("Graham v. Florida," 2010). Part of the reason for the

Singer, Simon I.

2011-01-01

358

Nursing Process. Nursing: Basic Needs I. Nursing: Basic Needs II. Nursing through the Life Span. Entry into Professional Nursing. A Basic Course Outline (College Freshmen) for Nursing. A Four Year "2+2" Articulated Curriculum for the Occupation of Nursing.  

ERIC Educational Resources Information Center

This course outline provides materials for third-year courses in a "2+2" curriculum for the occupation of registered nurse. It is part of a planned and articulated 4-year curriculum that spans the junior and senior years of high school and the freshman and sophomore years of the postsecondary institution. Introductory materials include: the

Maddox, Gaylon; And Others

359

Life history strategies in zooplankton communities: The significance of female gonad morphology and maturation types for the reproductive biology of marine calanoid copepods  

NASA Astrophysics Data System (ADS)

The present review addresses the reproductive strategies of marine calanoid copepods, as affected by their physiological preconditioning, and aims to enhance understanding of their adaptations to specific environmental conditions. Knowledge about oocyte development and internal gonad structure, especially in relation to feeding conditions, is essential for a complete understanding of the reproductive strategies of the copepods. Therefore, the foci of the review are to identify general patterns in oocyte and gonad development in calanoid copepod species from marine ecosystems worldwide and to elucidate the significance of gonad structures for reproductive strategies. Oogenesis is similar in all copepod species. During maturation, the morphology of the oocytes changes distinctly and, according to oocyte size and appearance of ooplasm and nucleus, five oocyte developmental stages are distinguished. In contrast, the gonad structure and its changes during the spawning cycle differ considerably among species, and these differences are related to specific reproductive traits. Four gonad morphology types can be distinguished: the Calanus-type, found in species from all over the world with distinctly different life history traits, is apparently most common in calanoid copepods. In this gonad type, most oocyte developmental stages are present simultaneously, and usually many oocytes mature synchronously, all of which are released in one clutch. The gonad structure allows frequent spawning and large clutches, hence, high egg production rates. This may be a preconditioning for exploiting seasonally high food supply. However, the Calanus-type was also found in species producing eggs at lower rates. In the diverticula of Pseudocalanus-type gonads, only two oocyte developmental stages are present and usually fewer oocytes mature synchronously. Accordingly, the egg production rate is generally lower as compared to the Calanus-type, and apparently only this gonad-type is structurally suitable for ovigerity. Species with Pseudocalanus-type gonads are present from polar seas to the tropics, some of them being key species. The Acartia-type was scarce, found in only one species, Acartia clausi. Here all oocyte developmental stages are present, including intermediate stages, but only a few oocytes mature synchronously and are released together. High spawning frequency compensates for the small clutches, and hence egg production rate may be as high as in Calanus-type gonads. In the Aetidius-type gonad, the total number of oocytes in the diverticula is low as is the number of oocytes maturing synchronously. Less is known about the reproductive biology of species with Aetidius-type gonads; however, their distribution and feeding patterns suggest that this type is common in species inhabiting environments of low food availability. The differences in gonad structures also lead to differences in the egg size:female size ratio, as the space available for each mature oocyte depends on the total number of oocytes. Independent from gonad-type, the eggs are relatively large in species in which the gonads contain only few oocytes, whereas small eggs are produced by species with gonads filled with many oocytes. Since all species carrying their eggs in external sacs until hatching (ovigerous species) have Pseudocalanus-type gonads, the scatter in their egg size:female size ratio is low. The broadcast spawning species are of all gonad-types, and consequently the scatter among them is high. A major factor affecting the timing and magnitude of spawning of calanoid copepods is the energy supply for gonad development. Therefore, part of the review elucidates the role of internal and external resources in fuelling egg production. In many species, freshly assimilated food is transferred into egg material within a short period of time, and clutch size and spawning frequency are the two parameters that allow adjustment of egg production to food availability and temperature. However, internal body reserves may also fuel oocyte development. The extent to which oogene

Niehoff, Barbara

2007-07-01

360

Dynamic Capacitated Minimum Spanning Trees  

E-print Network

Given a set of terminals, each associated with a positive number denoting the traffic to be routed to a central terminal (root), the Capacitated Minimum Spanning Tree (CMST) problem asks for a minimum spanning tree, spanning all terminals, such that the amount of traffic routed from a subtree, linked to the root by an edge, does not exceed the given capacity constraint k. The CMST problem is NP-complete and has been extensively studied for the past 40 years. Current best heuristics, in terms of cost and computation time (O(n log n)), are due to Esau and Williams [1], and Jothi and Raghavachari [2].

Raja Jothi; Balaji Raghavachari

2004-01-01

361

The politics of reproduction.  

PubMed

The topic of human reproduction encompasses events throughout the human and especially female life-cycle as well as ideas and practices surrounding fertility, birth, and child care. Most of the scholarship on the subject, up through the 1960s, was based on cross-cultural surveys focused on the beliefs, norms, and values surrounding reproductive behaviors. Multiple methodologies and subspecialties, and fields like social history, human biology, and demography were utilized for the analysis. The concept of the politics of reproduction synthesizes local and global perspectives. The themes investigated include: the concept of reproduction, population control, and the internationalization of state and market interests (new reproductive technologies); social movements and contested domains; medicalization and its discontents; fertility and its control; adolescence and teen pregnancy; birth; birth attendants; the construction of infancy and the politics of child survival; rethinking the demographic transition; networks of nurturance; and meanings of menopause. The medicalization of reproduction is a central issue of studies of birth, midwifery, infertility, and reproductive technologies. Scholars have also analyzed different parts of the female life-cycle as medical problems. Other issues worth analysis include the internationalization of adoption and child care workers; the crisis of infertility of low-income and minority women who are not candidates for expensive reproductive technologies; the concerns of women at high risk for HIV whose cultural status depends on their fertility; questions of reproduction concerning, lesbians and gay men (artificial insemination and discrimination in child rearing); the study of menopause; and fatherhood. New discourse analysis is used to analyze state eugenic policies; conflicts over Western neocolonial influences in which women's status as childbearers represent nationalist interests; fundamentalist attacks on abortion rights; and the AIDS crisis. PMID:12288961

Ginsburg, F; Rapp, R

1991-01-01

362

Luteal-phase support in assisted reproduction treatment: real-life practices reported worldwide by an updated website-based survey.  

PubMed

An updated worldwide web-based survey assessed the real-life clinical practices regarding luteal-phase supplementation (LPS) in assisted reproduction. This survey looked for changes since a former survey conducted nearly 3years earlier. The survey questions were: If you support the luteal phase, when do you start the regimen you are using?; Which agent/route is your treatment of choice to support the luteal phase?; If you use vaginal progesterone, which formulation do you use?; and How long you continue progesterone supplementation if the patient conceived? Data were obtained from 408 centres (82 countries) representing 284,600 IVF cycles/year. The findings were: (i) most practitioners (80% of cycles) start LPS on the day of egg collection; (ii) in >90%, a vaginal progesterone product is used (77% as a single agent and 17% in combination with i.m. progesterone), while human chorionic gonadotrophin as a single agent for LPS is not being used at all; and (iii) in 72% of cycles, LPS is administered until 8-10weeks' gestation or beyond. When compared with the initial survey, the results of this survey are encouraging as there is a clear shift towards a more unified and evidence-based approach to LPS in IVF cycles. This updated worldwide web-based survey assessed the actual real-life clinical practices regarding luteal-phase supplementation (LPS) in assisted reproduction. Specifically, this survey looked for changes since an initial survey conducted nearly 3years earlier. The survey included the following questions: If you support the luteal phase, when do you start the regimen you are using?; Which agent/route is your treatment of choice to support the luteal phase?; If you use vaginal progesterone, which formulation do you use?; and How long you continue progesterone supplementation if the patient conceived? Data from 408 centres in 82 countries representing a total of 284,600 IVF cycles/year were included. Most practitioners (80% of cycles) start LPS on the day of egg collection and in more than 90% a vaginal progesterone product is used for LPS (in 77% as a single agent and in 17% in combination with i.m. progesterone). As a single agent for LPS, human chorionic gonadotrophin is not being used at all. Regarding the duration of supplementation, in 72% of cycles, LPS is administered until 8-10weeks' gestation or beyond. When compared with the initial survey from 2009, the results of this updated survey are encouraging as there is a clear shift towards a more unified and evidence-based approach to luteal-phase support in IVF cycles. Nevertheless, although there is no firm evidence supporting the continuation of LPS after the demonstration of fetal heart beat on ultrasound, this remains the common practice of the majority of assisted reproduction centres worldwide. PMID:24447959

Vaisbuch, Edi; de Ziegler, Dominique; Leong, Milton; Weissman, Ariel; Shoham, Zeev

2014-03-01

363

Optimal life-history strategy differs between philopatric and dispersing individuals in a metapopulation.  

PubMed

Abundant empirical evidence for dispersal syndromes contrasts with the rarity of theoretical predictions about the evolution of life-history divergence between dispersing and philopatric individuals. We use an evolutionary model to predict optimal differences in age-specific reproductive effort between dispersing and philopatric individuals inhabiting the same metapopulation. In our model, only young individuals disperse, and their lifelong reproductive decisions are potentially affected by this initial event. Juvenile survival declines as density of adults and other juveniles increases. We assume a trade-off between reproduction and survival, so that different patterns of age-specific reproductive effort lead to different patterns of aging. We find that young immigrant mothers should allocate more resources to reproduction than young philopatric mothers, but these life-history differences vanish as immigrant and philopatric individuals get older. However, whether the higher early reproductive effort of immigrants results in higher fecundity depends on the postimmigration cost on fecundity. Dispersing individuals have consequently a shorter life span. Ultimately, these life-history differences are due to the fact that young dispersing individuals most often live in recently founded populations, where competition is relaxed and juvenile survival higher, favoring larger investment in offspring production at the expense of survival. PMID:24561601

Cotto, Olivier; Kubisch, Alexander; Ronce, Ophlie

2014-03-01

364

Primate energy expenditure and life history.  

PubMed

Humans and other primates are distinct among placental mammals in having exceptionally slow rates of growth, reproduction, and aging. Primates' slow life history schedules are generally thought to reflect an evolved strategy of allocating energy away from growth and reproduction and toward somatic investment, particularly to the development and maintenance of large brains. Here we examine an alternative explanation: that primates' slow life histories reflect low total energy expenditure (TEE) (kilocalories per day) relative to other placental mammals. We compared doubly labeled water measurements of TEE among 17 primate species with similar measures for other placental mammals. We found that primates use remarkably little energy each day, expending on average only 50% of the energy expected for a placental mammal of similar mass. Such large differences in TEE are not easily explained by differences in physical activity, and instead appear to reflect systemic metabolic adaptation for low energy expenditures in primates. Indeed, comparisons of wild and captive primate populations indicate similar levels of energy expenditure. Broad interspecific comparisons of growth, reproduction, and maximum life span indicate that primates' slow metabolic rates contribute to their characteristically slow life histories. PMID:24474770

Pontzer, Herman; Raichlen, David A; Gordon, Adam D; Schroepfer-Walker, Kara K; Hare, Brian; O'Neill, Matthew C; Muldoon, Kathleen M; Dunsworth, Holly M; Wood, Brian M; Isler, Karin; Burkart, Judith; Irwin, Mitchell; Shumaker, Robert W; Lonsdorf, Elizabeth V; Ross, Stephen R

2014-01-28

365

Primate energy expenditure and life history  

PubMed Central

Humans and other primates are distinct among placental mammals in having exceptionally slow rates of growth, reproduction, and aging. Primates slow life history schedules are generally thought to reflect an evolved strategy of allocating energy away from growth and reproduction and toward somatic investment, particularly to the development and maintenance of large brains. Here we examine an alternative explanation: that primates slow life histories reflect low total energy expenditure (TEE) (kilocalories per day) relative to other placental mammals. We compared doubly labeled water measurements of TEE among 17 primate species with similar measures for other placental mammals. We found that primates use remarkably little energy each day, expending on average only 50% of the energy expected for a placental mammal of similar mass. Such large differences in TEE are not easily explained by differences in physical activity, and instead appear to reflect systemic metabolic adaptation for low energy expenditures in primates. Indeed, comparisons of wild and captive primate populations indicate similar levels of energy expenditure. Broad interspecific comparisons of growth, reproduction, and maximum life span indicate that primates slow metabolic rates contribute to their characteristically slow life histories. PMID:24474770

Pontzer, Herman; Raichlen, David A.; Gordon, Adam D.; Schroepfer-Walker, Kara K.; Hare, Brian; ONeill, Matthew C.; Muldoon, Kathleen M.; Dunsworth, Holly M.; Wood, Brian M.; Isler, Karin; Burkart, Judith; Irwin, Mitchell; Shumaker, Robert W.; Lonsdorf, Elizabeth V.; Ross, Stephen R.

2014-01-01

366

Effects of dietary selenomethionine on cutthroat trout (Oncorhynchus clarki bouvieri) growth and reproductive performance over a life cycle.  

PubMed

A 2.5-year feeding trial was conducted in which cutthroat trout (Oncorhynchus clarki bouvieri) were fed either a basal diet (1.2 microg Se/g diet) or the basal diet supplemented with 2, 4, 6, 8, or 10 microg Se/g diet as selenomethionine from 1 g weight to maturation [corrected]. After 44 weeks of feeding, a subsample of fish was removed from dietary treatment groups and fed the basal diet for an additional 32 weeks. Concentrations of Se in whole fish and eggs increased in proportion to dietary Se intake, but no differences in growth, feed intake, survival, or egg hatchability were observed among dietary groups. Cranial-facial deformities in second-generation offspring were less than 6% in all treatment groups except for fish fed the diet supplemented with 4 microg Se/g diet as selenomethionine [corrected], where a 9.2% incidence was observed. Fish switched from selenomethionine-supplemented diets to the basal diet lost Se, calculated as microg Se lost/g weight gain, at 1.01, 2.84, 4.42, and 4.42 for dietary treatment groups 3, 4, 5, and 6, respectively. Results suggest no toxicity of dietary selenomethionine up to 10 microg/g supplemented diet and that with total life-cycle exposure, cutthroat trout increase Se excretion to maintain whole-body concentrations below toxic levels. PMID:19763677

Hardy, Ronald W; Oram, Libbie L; Mller, Gregory

2010-01-01

367

Reproductive Hazards  

MedlinePLUS

... and female reproductive systems play a role in pregnancy. Problems with these systems can affect fertility and ... a reproductive hazard can cause different effects during pregnancy, depending on when she is exposed. During the ...

368

âThe Calamity of So Long Lifeâ: Life Histories, Contaminants, and Potential Emerging Threats to Long-lived Vertebrates  

NSDL National Science Digital Library

Persistent contaminants are ubiquitous in the environment, often present at concentrations that may jeopardize reproductive fitness only after long periods of exposure. As the duration of exposure is largely regulated by life span, long-lived species of high trophic status, such as many reptiles, birds, and mammals, may be at risk of reduced fitness and population decline. Delayed maturation and iteroparity confer the potential for cumulative effects to be expressed prior to reproduction, and large parental investments in yolk and milk may threaten offspring because of exposure during critical developmental periods. Long generation times may delay emergence of obvious effects on populations, perhaps eluding early intervention, while constraining rates at which populations may recover if conditions subsequently improve. Life history theory thus suggests that the suite of traits that optimized reproductive fitness throughout long-lived species' evolutionary histories may ultimately put them in peril in the modern, anthropogenically altered environment.

Christopher L. Rowe (University of Maryland;)

2008-08-01

369

VIV analysis of pipelines under complex span conditions  

NASA Astrophysics Data System (ADS)

Spans occur when a pipeline is laid on a rough undulating seabed or when upheaval buckling occurs due to constrained thermal expansion. This not only results in static and dynamic loads on the flowline at span sections, but also generates vortex induced vibration (VIV), which can lead to fatigue issues. The phenomenon, if not predicted and controlled properly, will negatively affect pipeline integrity, leading to expensive remediation and intervention work. Span analysis can be complicated by: long span lengths, a large number of spans caused by a rough seabed, and multi-span interactions. In addition, the complexity can be more onerous and challenging when soil uncertainty, concrete degradation and unknown residual lay tension are considered in the analysis. This paper describes the latest developments and a state-of-the-art finite element analysis program that has been developed to simulate the span response of a flowline under complex boundary and loading conditions. Both VIV and direct wave loading are captured in the analysis and the results are sequentially used for the ultimate limit state (ULS) check and fatigue life calculation.

Wang, James; Steven Wang, F.; Duan, Gang; Jukes, Paul

2009-06-01

370

The SPAN cookbook: A practical guide to accessing SPAN  

NASA Technical Reports Server (NTRS)

This is a manual for remote users who wish to send electronic mail messages from the Space Physics Analysis Network (SPAN) to scientific colleagues on other computer networks and vice versa. In several instances more than one gateway has been included for the same network. Users are provided with an introduction to each network listed with helpful details about accessing the system and mail syntax examples. Also included is information on file transfers, remote logins, and help telephone numbers.

Mason, Stephanie; Tencati, Ronald D.; Stern, David M.; Capps, Kimberly D.; Dorman, Gary; Peters, David J.

1990-01-01

371

Effects of produced water on reproduction and early life stages of the purple sea urchin (Strongylocentrotus purpuratus): Field and laboratory tests  

SciTech Connect

This dissertation focuses on the effects of produced water (an oil-production effluent) on reproduction in the purple sea urchin (Strongy-locentrotus purpuratus) using both field and laboratory experiments. The author investigated the effects of chronic exposure to produced water on the gametogenesis and gamete performance using an in-situ caging experiment. He found a significant negative relationship between gonad mass and cage distance for both sexes, indicating that urchins living closer to the outfall produced significantly larger gonads. He also found significant differences in the fertilizability of eggs between cages and this showed a positive relationship with distance from the outfall. These findings indicate that while urchins exposed to a produced water outfall produce large gonads, they suffer a marked decrease in gamete performance. In a subsequent study the author explored whether and how brief exposure to a range of concentrations of produced water affected gametes and early larval stages of the purple sea urchin. Specifically, he exposed separately and together, eggs, sperm, and zygotes to ascertain the relative sensitivities of these life stages to produced water at durations and concentrations realistic to each state. He also explored the nature of the biological responses, and the potential for delayed expression. I found that both apparent fertilization and embryonic developmental success showed decreased performance with increasing produced water concentrations. Produced water exposure effectively slowed embryological developmental rates, but did not affect embryo survivorship. The spatial and temporal variability in toxicity of receiving waters was addressed using a fertilization bioassay. Receiving waters were collected along a transect down-field from the discharge on three dates while the outfall was actively discharging, and on one date while the plant was not discharging.

Krause, P.R.

1993-01-01

372

Temporal variability in the life history and reproductive biology of female dugongs in Torres Strait: The likely role of sea grass dieback  

NASA Astrophysics Data System (ADS)

The extensive sea grass meadows in Torres Strait enable it to be a globally important habitat for the dugong, Dugong dugon, a marine mammal of cultural and dietary significance to Torres Strait Islanders and the basis for the substantial island-based fishery in the Torres Strait Protected Zone. Torres Strait sea grass communities are subjected to episodic diebacks which are now believed to be largely natural events. Information on dugong life history was obtained from specimens obtained from female dugongs as they were butchered for food by Indigenous hunters at two major dugong hunting communities in Torres Strait: Daru (9.04S, 143.21E) in 1978-1982 (a time of sea grass dieback and recovery) and Mabuiag Island (9.95S, 142.15E) in 1997-1999 (when sea grasses were abundant). Dugongs sampled in 1997-1999 had their first calf at younger ages (minimum of 6 cf. 10 years), and more frequently (interbirth interval based on all possible pregnancies 2.60.4 (S.E.) yr cf. 5.81.0 yr) than the dugongs sampled in 1978-1982. Pregnancy rates increased monotonically during 1978-1982, coincident with sea grass recovery. The age distribution of the female dugongs collected in 1997-1999 also suggested a low birth rate between 1973 and 1983 and/or or a high level of mortality for animals born during this period. These results add to the evidence from other regions that the life history and reproductive rate of female dugongs are adversely affected by sea grass loss, the effect of which cannot be separated from a possible density-dependent response to changes in dugong population size. Many green turtles in Torres Strait were also in poor body condition coincident with the 1970s sea grass dieback. The impacts of future sea grass diebacks need to be anticipated when management options for the traditional Torres Strait fisheries for dugongs and green turtles are evaluated.

Marsh, Helene; Kwan, Donna

2008-09-01

373

Exploring the Dimensionality of Digit Span  

ERIC Educational Resources Information Center

The Digit Span subtest from the Wechsler Scales is used to measure Freedom from Distractibility or Working Memory. Some published research suggests that Digit Span forward should be interpreted differently from Digit Span backward. The present study explored the dimensionality of the Wechsler Memory Scale-III Digit Span (forward and backward)

Bowden, Stephen C.; Petrauskas, Vilija M.; Bardenhagen, Fiona J.; Meade, Catherine E.; Simpson, Leonie C.

2013-01-01

374

Variation in the reproductive rate of bats  

Microsoft Academic Search

In many respects, bats have relatively slow life histories. However, the reproductive rate of bats (i.e., the proportion of females that reproduce in any breeding season) has not been critically examined. We compiled data on the reproductive rates of bats to test predictions based on life-history theory. Among 257 samples from 103 species, re - productive rate varied considerably and

Robert M. R. Barclay; Joel Ulmer; Cameron J. A. MacKenzie; Megan S. Thompson; Leif Olson; Julianne McCool; Elvie Cropley; Graeme Poll

2004-01-01

375

Reproductive ecology of female chimpanzees.  

PubMed

An important adaptive problem for mammals in general, and primates in particular, is how females can manage the high costs of reproduction in the face of fluctuating energetic supplies. For many species, the best solution is to breed seasonally such that high costs are temporally coincident with predictable periods of resource abundance. This is an unreliable strategy for some primates, such as chimpanzees (Pan troglodytes), for which large body size forces an increase in dietary complexity and prolonged reproductive efforts. Here, I review data on reproductive function in chimpanzees, a species that demonstrates a risk-averse reproductive strategy wherein reproductive investment is allocated in accordance with maternal condition. Life history parameters for chimpanzees indicate that most females produce very few surviving offspring. However, comparisons between captive and wild populations and within wild populations illustrate that variation in resource access leads to highly variable reproductive success. Focused hormonal studies have demonstrated these effects at a proximate level, with energetic influences on female dispersal, receptivity, cycle quality, conception success, and lactational amenorrhea. Downstream of these effects, female reproductive function affects sexual attractiveness, and by virtue of males' own optimal reproductive strategies, can lead to coercive aggression and decreased foraging efficiency. Because of their extreme reproductive costs, female chimpanzees utilize a highly conservative reproductive strategy, one that minimizes the costs of ecological variation but makes them vulnerable to sexual conflict and costs of sociality. PMID:23015287

Thompson, Melissa Emery

2013-03-01

376

Hibernation is associated with increased survival and the evolution of slow life histories among mammals  

PubMed Central

Survival probability is predicted to underlie the evolution of life histories along a slowfast continuum. Hibernation allows a diverse range of small mammals to exhibit seasonal dormancy, which might increase survival and consequently be associated with relatively slow life histories. We used phylogenetically informed GLS models to test for an effect of hibernation on seasonal and annual survival, and on key attributes of life histories among mammals. Monthly survival was in most cases higher during hibernation compared with the active season, probably because inactivity minimizes predation. Hibernators also have approximately 15 per cent higher annual survival than similar sized non-hibernating species. As predicted, we found an effect of hibernation on the relationships between life history attributes and body mass: small hibernating mammals generally have longer maximum life spans (50% greater for a 50 g species), reproduce at slower rates, mature at older ages and have longer generation times compared with similar-sized non-hibernators. In accordance with evolutionary theories, however, hibernating species do not have longer life spans than non-hibernators with similar survival rates, nor do they have lower reproductive rates than non-hibernators with similar maximum life spans. Thus, our combined results suggest that (i) hibernation is associated with high rates of overwinter and annual survival, and (ii) an increase in survival in hibernating species is linked with the coevolution of traits indicative of relatively slow life histories. PMID:21450735

Turbill, Christopher; Bieber, Claudia; Ruf, Thomas

2011-01-01

377

Animal Reproduction  

NSDL National Science Digital Library

This Topic in Depth takes a look at organizations and educational websites concerned with reproduction in humans and other animals. The Society for the Study of Reproduction (SSR) "is an association of scientists and physicians interested in research in reproduction. Some members are engaged in basic or applied research, while others perform clinical practice." The SSR website (1) contains downloadable copies of the SSR Newsletter; position statements; and information about meetings, awards, and the organization. The Society for Reproduction and Fertility (SRF) "is open to scientists and students worldwide, who work on any aspect of reproductive biology or fertility in man and animals." The SRF website (2) contains sections regarding News, Events, Jobs, Honours, and Grants. SRF makes downloadable copies of its newsletter available as well. The primary aim of the European Society of Human Reproduction & Embryology (ESHRE) "is to promote interest in, and understanding of, reproductive biology and medicine. It does this through facilitating research and subsequent dissemination of research findings in human reproduction and embryology to the general public, scientists, clinicians and patient associations; it also works to inform politicians and policy makers throughout Europe." The ESHRE site (3) contains information about activities, membership, publications, special interest groups, and jobs. The primary function of the Centre for Reproductive Biology in Uppsala (CRU) "is to increase the knowledge about reproduction in animals and humans by applying a more comprehensive view on reproductive biology." CRU is composed of scientists from both Uppsala University and the Swedish University of Agricultural Science. The CRU site (4) contains information about a number of publications, and contact information for CRU members. The Population Council is a nonprofit "organization that conducts biomedical, social science, and public health research." The "Council's reproductive biology and immunology program undertakes fundamental research in the reproductive sciences and immunological processes related to sexually transmitted infections, particularly HIV." This website (5) provides information about different aspects of the research program including Germ Cell Dynamics, Sperm Maturation, and Physiology of Sertoli Cells. From Dr. Michael Gregory of Clinton Community College, the next site (6) is a concise overview of animal reproduction which addresses important aspects of sexual reproduction, and male and female reproductive systems. The final site (7) contains lecture notes regarding avian reproduction from Dr. Gary Ritchison's Ornithology course at Eastern Kentucky University. The lecture notes are interspersed with some especially nice images and diagrams.

378

Animal Reproduction  

NSDL National Science Digital Library

What animals abandon their offspring? Find out this and more as you explore reproduction in the animal world. Did you know that all animals must reproduce to survive? In this project you will be learning some interesting facts about reproduction in animals. After you have some background information you will have a chance to select 3 animals and complete a chart on reproduction. TASK: Day 1 ...

Mrs. Joggerst

2008-03-30

379

2.MD Hand Span Measures  

NSDL National Science Digital Library

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: Hand span is a measure of distance from the tip of the thumb to the tip of the little finger with the hand fully extended. Each student places his or h...

380

88. Reproduction from glass plate negative (original in Modjeski and ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

88. Reproduction from glass plate negative (original in Modjeski and Masters office, Harrisburg, Pennsylvania, Modjeski Collection, No. 4, not dated) LOOKING DOWNSTREAM - Burlington Northern Railroad Bridge, Spanning Willamette River at River Mile 6.9, Portland, Multnomah County, OR

381

92. Reproduction from glass plate negative (Modjeski and Masters office, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

92. Reproduction from glass plate negative (Modjeski and Masters office, Modjeski Collection No. 70, December 24, 1906) CAISSON No. 2 - Burlington Northern Railroad Bridge, Spanning Willamette River at River Mile 6.9, Portland, Multnomah County, OR

382

94. Reproduction from glass plate negative (Modjeski and Masters office, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

94. Reproduction from glass plate negative (Modjeski and Masters office, Modjeski Collection, No. 106, May 13, 1907) CAISSON No. 3 - Burlington Northern Railroad Bridge, Spanning Willamette River at River Mile 6.9, Portland, Multnomah County, OR

383

96. Reproduction from glass plate negative (Modjeski and Masters office, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

96. Reproduction from glass plate negative (Modjeski and Masters office, Modjeski Collection, No. 161, March 2, 1908) DERRICK AT PIER 2 - Burlington Northern Railroad Bridge, Spanning Willamette River at River Mile 6.9, Portland, Multnomah County, OR

384

90. Reproduction from glass plate negative (Modjeski and Masters office, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

90. Reproduction from glass plate negative (Modjeski and Masters office, Modjeski Collection, No. 26, August 24, 1906) INTERIOR OF ENGINE ROOM, PRESSURE BARGE - Burlington Northern Railroad Bridge, Spanning Willamette River at River Mile 6.9, Portland, Multnomah County, OR

385

99. Reproduction from glass plate negative (Modjeski and Masters office, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

99. Reproduction from glass plate negative (Modjeski and Masters office, Modjeski Collection, No. 183, May 6, 1908) SETTING CENTER CASTING - Burlington Northern Railroad Bridge, Spanning Willamette River at River Mile 6.9, Portland, Multnomah County, OR

386

91. Reproduction from glass plate negative (Modjeski and Masters office, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

91. Reproduction from glass plate negative (Modjeski and Masters office, Modjeski Collection, No. 44, October 13, 1906) SANDBAGGING PIER No. 4 - Burlington Northern Railroad Bridge, Spanning Willamette River at River Mile 6.9, Portland, Multnomah County, OR

387

93. Reproduction from glass plate negative (Modjeski and Masters office, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

93. Reproduction from glass plate negative (Modjeski and Masters office, Modjeski Collection, No. 92, February 9, 1907) CAISSON No. 3 JUST BEFORE LAUNCHING - Burlington Northern Railroad Bridge, Spanning Willamette River at River Mile 6.9, Portland, Multnomah County, OR

388

Differential memory span--abnormal lateralization pattern in schizophrenic patients and their siblings?  

PubMed

The recurring digit span test is hypothesized to assess consolidation memory and hypothetically addresses neuropsychological left-temporohippocampal functioning, an area of the brain which is presumed to play a crucial role in schizophrenia. The present study applied the recurring digit span memory test and the recurring block span memory test (assumed to be an indicator of right-temporohippocampal functioning) to 106 acute schizophrenic patients (DSM-III-R), 49 siblings of these patients without DSM-III-R lifetime diagnoses as well as 53 non-related control subjects without DSM-III-R lifetime diagnoses. Results of our investigation indicate that schizophrenic patients differ from control subjects regarding recurring digit span in a reduced number of correct reproductions of recurring trials. Since performance of schizophrenic patients was only non-significantly different from control subjects regarding recurring block span memory, our findings point to a task-specific memory impairment in schizophrenia and argue against a generalized deficit in this disease. Furthermore, individuals at risk for schizophrenia also differed from control subjects concerning the recurring digit span memory test but not with regard to the recurring block span test. Therefore we conclude that the reduced cumulative learning curve of verbal material (reduced number of correct reproduction of recurring digit trials) in schizophrenic patients and their healthy siblings might represent a marker for the liability to schizophrenia and parallels neuroimaging findings concerning left-sided temporohippocampal abnormalities in this disease, which presumably play a key role in the etiology of schizophrenia. PMID:10610054

Franke, P; Gnsicke, M; Schmitz, S; Falkai, P; Maier, W

1999-12-01

389

THE DISCOUNTED REPRODUCTIVE NUMBER FOR EPIDEMIOLOGY  

PubMed Central

The basic reproductive number, , and the effective reproductive number, , are commonly used in mathematical epidemiology as summary statistics for the size and controllability of epidemics. However, these commonly used reproductive numbers can be misleading when applied to predict pathogen evolution because they do not incorporate the impact of the timing of events in the life-history cycle of the pathogen. To study evolution problems where the host population size is changing, measures like the ultimate proliferation rate must be used. A third measure of reproductive success, which combines properties of both the basic reproductive number and the ultimate proliferation rate, is the discounted reproductive number . The discounted reproductive number is a measure of reproductive success that is an individuals expected lifetime offspring production discounted by the background population growth rate. Here, we draw attention to the discounted reproductive number by providing an explicit definition and a systematic application framework. We describe how the discounted reproductive number overcomes the limitations of both the standard reproductive numbers and proliferation rates, and show that is closely connected to Fishers reproductive values for different life-history stages PMID:19364158

Reluga, Timothy C.; Medlock, Jan; Galvani, Alison

2013-01-01

390

C-SPAN Networks: Professors' Guide.  

ERIC Educational Resources Information Center

The intention of this guide is to serve as a forum for college faculty members to share ideas and articles about using C-SPAN programming in college classrooms and in academic research. The first article, "C-SPAN as a 'Lecture Launcher'" (Stephen Frantzich) illustrates how well-chosen segments of C-SPAN programming can be used to stimulate

C-SPAN in the Classroom, 1993

1993-01-01

391

Individual variation in reproductive costs of reproduction: high-quality females always do better  

Microsoft Academic Search

Summary 1. Although life-history theory predicts substantial costs of reproduction, individuals often show positive correlations among life-history traits, rather than trade-offs. The apparent absence of reproductive costs may result from heterogeneity in individual quality. 2. Using detailed longitudinal data from three contrasted ungulate populations (mountain goats, Oreamnos americanus ; bighorn sheep, Ovis canadensis ; and roe deer, Capreolus capreolus ),

Sandra Hamel; Steeve D. Ct; Jean-Michel Gaillard; Marco Festa-Bianchet

2009-01-01

392

Octave-spanning semiconductor laser  

E-print Network

We present here a semiconductor injection laser operating in continuous wave with an emission covering more than one octave in frequency, and displaying homogeneous power distribution among the lasing modes. The gain medium is based on a heterogeneous quantum cascade structure operating in the THz range. Laser emission in continuous wave takes place from 1.64 THz to 3.35 THz with optical powers in the mW range and more than 80 modes above threshold. Free-running beatnote investigations on narrow waveguides with linewidths of 980 Hz limited by jitter indicate frequency comb operation on a spectral bandwidth as wide as 624 GHz, making such devices ideal candidates for octave-spanning semiconductor-laser-based THz frequency combs.

Rsch, Markus; Beck, Mattias; Faist, Jrme

2014-01-01

393

C-SPAN: The Communicators  

NSDL National Science Digital Library

C-SPAN has given viewers programs like the celebrated "BookTV" and "Booknotes" and now they have come out with "The Communicators". This program features a half-hour interview with "the people who shape our digital future." Interviews include the acting chairman of the Federal Communications Commission (FCC), Fred Humphries of Microsoft Corporation's Federal Affairs division, and legislators concerned with such matters. At the top of the site's homepage, visitors will find the latest interview in the series, complete with additional relevant web resources. Further down the homepage, visitors will find a link to their podcasts, along with a complete listing of "Recent Events". The site is rounded out by a detailed set of "Web Resources" related to the federal government, which can be found on the right-hand side of the page.

394

Octave-spanning semiconductor laser  

NASA Astrophysics Data System (ADS)

We present a semiconductor injection laser operating in continuous wave with emission covering more than one octave in frequency and displaying homogeneous power distribution among the lasing modes. The gain medium is based on a heterogeneous quantum cascade structure operating in the terahertz range. Laser emission in continuous wave takes place from 1.64?THz to 3.35?THz with optical powers in the milliwatt range and more than 80 modes above threshold. For narrow waveguides, a collapse of the free-running beatnote to linewidths of 980?Hz, limited by jitter, indicate frequency comb operation on a spectral bandwidth as wide as 624?GHz, making such devices ideal candidates for octave-spanning semiconductor-laser-based terahertz frequency combs.

Rsch, Markus; Scalari, Giacomo; Beck, Mattias; Faist, Jrme

2015-01-01

395

97. Reproduction from glass plate negative (Modjeski and Masters office, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

97. Reproduction from glass plate negative (Modjeski and Masters office, Modjeski Collection, No. 180, May 20, 1908) LOADING BEAMS OF WILLAMETTE BRIDGE DRAW SPAN - Burlington Northern Railroad Bridge, Spanning Willamette River at River Mile 6.9, Portland, Multnomah County, OR

396

Size and age compositions and reproductive biology of the nervous shark Carcharhinus cautus in a large subtropical embayment, including an analysis of growth during pre- and postnatal life  

Microsoft Academic Search

The lengths-at-age of individuals of the nervous shark Carcharhinus cautus in Shark Bay, Western Australia, have been determined and used to explore the types of situation when it might be advisable to shift from employing a von Bertalanffy equation to a more complex equation for describing the growth of this species and of elasmobranchs in general. The reproductive biology of

W. T. White; N. Hall; I. C. Potter

2002-01-01

397

An empirical test of evolutionary theories for reproductive senescence and reproductive effort in the garter snake Thamnophis elegans.  

PubMed

Evolutionary theory predicts that differential reproductive effort and rate of reproductive senescence will evolve under different rates of external mortality. We examine the evolutionary divergence of age-specific reproduction in two life-history ecotypes of the western terrestrial garter snake, Thamnophis elegans. We test for the signature of reproductive senescence (decreasing fecundity with age) and increasing reproductive effort with age (increasing reproductive productivity per gram female) in replicate populations of two life-history ecotypes: snakes that grow fast, mature young and have shorter lifespans, and snakes that grow slow, mature late and have long lives. The difference between life-history ecotypes is due to genetic divergence in growth rate. We find (i) reproductive success (live litter mass) increases with age in both ecotypes, but does so more rapidly in the fast-growth ecotype, (ii) reproductive failure increases with age in both ecotypes, but the proportion of reproductive failure to total reproductive output remains invariant, and (iii) reproductive effort remains constant in fast-growth individuals with age, but declines in slow-growth individuals. This illustration of increasing fecundity with age, even at the latest ages, deviates from standard expectations for reproductive senescence, as does the lack of increases in reproductive effort. We discuss our findings in light of recent theories regarding the phenomenon of increased reproduction throughout life in organisms with indeterminate growth and its potential to offset theoretical expectations for the ubiquity of senescence. PMID:17251099

Sparkman, Amanda M; Arnold, Stevan J; Bronikowski, Anne M

2007-04-01

398

An empirical test of evolutionary theories for reproductive senescence and reproductive effort in the garter snake Thamnophis elegans  

PubMed Central

Evolutionary theory predicts that differential reproductive effort and rate of reproductive senescence will evolve under different rates of external mortality. We examine the evolutionary divergence of age-specific reproduction in two life-history ecotypes of the western terrestrial garter snake, Thamnophis elegans. We test for the signature of reproductive senescence (decreasing fecundity with age) and increasing reproductive effort with age (increasing reproductive productivity per gram female) in replicate populations of two life-history ecotypes: snakes that grow fast, mature young and have shorter lifespans, and snakes that grow slow, mature late and have long lives. The difference between life-history ecotypes is due to genetic divergence in growth rate. We find (i) reproductive success (live litter mass) increases with age in both ecotypes, but does so more rapidly in the fast-growth ecotype, (ii) reproductive failure increases with age in both ecotypes, but the proportion of reproductive failure to total reproductive output remains invariant, and (iii) reproductive effort remains constant in fast-growth individuals with age, but declines in slow-growth individuals. This illustration of increasing fecundity with age, even at the latest ages, deviates from standard expectations for reproductive senescence, as does the lack of increases in reproductive effort. We discuss our findings in light of recent theories regarding the phenomenon of increased reproduction throughout life in organisms with indeterminate growth and its potential to offset theoretical expectations for the ubiquity of senescence. PMID:17251099

Sparkman, Amanda M; Arnold, Stevan J; Bronikowski, Anne M

2007-01-01

399

Assessing the impacts of dimethoate on rotifers' reproduction through the pre-exposure history.  

PubMed

Organism usually undergoes an exposure of environmental pollution after a maternal exposure before birth. Traditional toxicological studies often initiated with rotifer neonates derived from the unexposed mothers while ignoring the pre-exposure (maternal exposure). The present study assessed the effect of dimethoate on the reproduction of the rotifer Brachionus calyciflorus, considering how the pre-exposure occurred in the parental generation influenced the subsequent impact. The F0 generation rotifers were exposed to the pesticide at five concentrations until the first F1 generation rotifers were reproduced. The neonates (F1 generation) were then exposed to the pesticide at the corresponding concentrations. The offspring reproduction, the time begins to reproduce, the duration of the reproductive period and the lifespan of the F1 generation rotifers were evaluated. Our results indicated that dimethoate influenced the maturation and reproduction of the rotifers. The highest concentration (1.8mgL(-1)) of dimethoate caused an inhibition in the offspring reproduction, shortened the life span and reduced the duration of the reproductive period. In addition, of particular interest in our study was that reproduction is also accelerated by the lowest concentration (0.2mgL(-1)). However, the pre-exposure had a significant effect on the subsequent impact. The dimethoate pre-exposure increased the impacts when the F1 generation rotifers were exposed to the substance, even at the same concentrations as in pre-exposure. It suggests that the maternal exposure history before birth is also important and has the long-lasting consequence from one generation to another. PMID:25450934

Guo, Ruixin; Chen, Jianqiu

2015-01-01

400

SHARP OBLIQUE PERSPECTIVE OF DECK AND APPROACH SPANS ALONG WITH ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

SHARP OBLIQUE PERSPECTIVE OF DECK AND APPROACH SPANS ALONG WITH PRINCIPLE CANTILEVER SPAN SHARP OBLIQUE PERSPECTIVE OF DECK AND APPROACH SPANS ALONG WITH PRINCIPLE CANTILEVER SPAN SHARP OBLIQUE PERSPECTIVE OF DECK AND APPROACH SPANS ALONG WITH PRINCIPLE CANTILEVER SPAN SHARP OBLIQUE PERSPECTIVE OF DECK AND APPROACH SPANS ALONG WITH PRINCIPLE CANTILEVER SPAN SHARP OBLIQUE PERSPECTIVE OF DECK AND APPROACH SPANS ALONG WITH PRINCIPLE CANTILEVER SPAN SHARP OBLIQUE PERSPECTIVE OF DECK AND APPROACH SPANS ALONG WITH PRINCIPLE CANTILEVER SPAN vSHARP OBLIQUE PERSPECTIVE OF DECK AND APPROACH SPANS ALONG WITH PRINCIPLE CANTILEVER SPAN SHARP OBLIQUE PERSPECTIVE OF DECK AND APPROACH SPANS ALONG WITH PRINCIPLE CANTILEVER SPAN SHARP OBLIQUE PERSPECTIVE OF DECK AND APPROACH SPANS ALONG WITH PRINCIPLE CANTILEVER SPAN - Snake River Bridge at Lyons' Ferry, State Route 261 spanning Snake River, Starbuck, Columbia County, WA

401

Racial and Ethnic Health Disparities in Reproductive Medicine: An Evidence-Based Overview  

PubMed Central

Racial and ethnic health disparities in reproductive medicine exist across the life span and are costly and burdensome to our healthcare system. Reduction and ultimate elimination of health disparities is a priority of the National Institutes of Health who requires reporting of race and ethnicity for all clinical research it supports. Given the increasing rates of admixture in our population, the definition and subsequent genetic significance of self-reported race and ethnicity used in health disparity research is not straightforward. Some groups have advocated using self-reported ancestry or carefully selected single-nucleotide polymorphisms, also known as ancestry informative markers, to sort individuals into populations. Despite the limitations in our current definitions of race and ethnicity in research, there are several clear examples of health inequalities in reproductive medicine extending from puberty and infertility to obstetric outcomes. We acknowledge that socioeconomic status, education, insurance status, and overall access to care likely contribute to the differences, but these factors do not fully explain the disparities. Epigenetics may provide the biologic link between these environmental factors and the transgenerational disparities that are observed. We propose an integrated view of health disparities across the life span and generations focusing on the metabolic aspects of fetal programming and the effects of environmental exposures. Interventions aimed at improving nutrition and minimizing adverse environmental exposures may act synergistically to reverse the effects of these epigenetic marks and improve the outcome of our future generations. PMID:23934691

Owen, Carter M.; Goldstein, Ellen H.; Clayton, Janine A.; Segars, James H.

2014-01-01

402

Extended attention span training system  

NASA Technical Reports Server (NTRS)

Attention Deficit Disorder (ADD) is a behavioral disorder characterized by the inability to sustain attention long enough to perform activities such as schoolwork or organized play. Treatments for this disorder include medication and brainwave biofeedback training. Brainwave biofeedback training systems feed back information to the trainee showing him how well he is producing the brainwave pattern that indicates attention. The Extended Attention Span Training (EAST) system takes the concept a step further by making a video game more difficult as the player's brainwaves indicate that attention is waning. The trainee can succeed at the game only by maintaining an adequate level of attention. The EAST system is a modification of a biocybernetic system that is currently being used to assess the extent to which automated flight management systems maintain pilot engagement. This biocybernetic system is a product of a program aimed at developing methods to evaluate automated flight deck designs for compatibility with human capabilities. The EAST technology can make a contribution in the fields of medical neuropsychology and neurology, where the emphasis is on cautious, conservative treatment of youngsters with attention disorders.

Pope, Alan T.; Bogart, Edward H.

1991-01-01

403

Early reproductive investment, senescence and lifetime reproductive success in female Asian elephants.  

PubMed

The evolutionary theory of senescence posits that as the probability of extrinsic mortality increases with age, selection should favour early-life over late-life reproduction. Studies on natural vertebrate populations show early reproduction may impair later-life performance, but the consequences for lifetime fitness have rarely been determined, and little is known of whether similar patterns apply to mammals which typically live for several decades. We used a longitudinal dataset on Asian elephants (Elephas maximus) to investigate associations between early-life reproduction and female age-specific survival, fecundity and offspring survival to independence, as well as lifetime breeding success (lifetime number of calves produced). Females showed low fecundity following sexual maturity, followed by a rapid increase to a peak at age 19 and a subsequent decline. High early life reproductive output (before the peak of performance) was positively associated with subsequent age-specific fecundity and offspring survival, but significantly impaired a female's own later-life survival. Despite the negative effects of early reproduction on late-life survival, early reproduction is under positive selection through a positive association with lifetime breeding success. Our results suggest a trade-off between early reproduction and later survival which is maintained by strong selection for high early fecundity, and thus support the prediction from life history theory that high investment in reproductive success in early life is favoured by selection through lifetime fitness despite costs to later-life survival. That maternal survival in elephants depends on previous reproductive investment also has implications for the success of (semi-)captive breeding programmes of this endangered species. PMID:24580655

Hayward, A D; Mar, K U; Lahdenper, M; Lummaa, V

2014-04-01

404

Reproductive Health  

NSDL National Science Digital Library

BioMed Central contains hundreds of important online journals in its archives, and Reproductive Health is certainly one that visitors will want to look over when they have a few moments. Reproductive Health is the official journal of the Geneva Foundation for Medical Education and Research, and was started in June 2004. It covers all aspects of human reproduction, and recent pieces have dealt with cervical cancer, maternity care, and other related topics. Visitors can view the ten most accessed articles from the journal, sign up to receive an RSS feed of the latest articles, and also email articles to friends and colleagues. For those who might be interested in submitting an article for consideration, they can also do that via this site.

405

Meditation improves self-regulation over the life span  

PubMed Central

The use of meditation to improve emotion and attention regulation has a long history in Asia and there are many practitioners in Western countries. Much of the evidence on the effectiveness of meditation is either anecdotal or a comparison of long-term meditators with controls matched in age and health. Recently, it has been possible to establish changes in self-regulation in undergraduate students after only 5 days of meditation practice, allowing randomized trials comparing effects of meditation with other self-control methods such as relaxation training. Early studies took place in Chinese universities; however, similar effects have been obtained with U.S. undergraduates, and with Chinese children aged 4.5 years and older Chinese participants aged 65 years. Studies using neuroimaging techniques have shown that meditation improves activation and connectivity in brain areas related to self-regulation, and these findings may provide an opportunity to examine remediation of mental disorders in a new light. PMID:24033306

Tang, Yi-Yuan; Posner, Michael I.; Rothbart, Mary K.

2014-01-01

406

Working Memory and Bias in Reasoning Across the Life Span  

Microsoft Academic Search

Age differences in syllogistic reasoning in relation to crystallized and fluid ability were studied in 278 adults from 19 to 96 years of age. Two reasoning tasks, the evaluation and the construction of conclusions for syllogisms of varying complexity and believability, a vocabulary test, and 3 tasks of working memory were administered. The magnitude of age-related variance on selected reasoning

Alberta S. Gilinsky; Ben B. Judd

1994-01-01

407

Assessment of Panic Disorder Across the Life Span  

Microsoft Academic Search

Panic disorder is a relatively common anxiety disorder that is often disabling. It may or may not be associated with agoraphobia. Panic disorder can be imitated by various medical illnesses, which, even when treated, can get cued with panic symptoms. It is also frequently comorbid with other psychiatric disorders including depression, generalized anxiety disorder, and substance use disorders. Although often

Vishal Madaan

408

Cell resilience in species life spans: a link to inflammation?  

E-print Network

, cell resil- ience during exposure to free radicals, hypoglycemia, hyperthermia, and various toxins has (ROS), low glucose, and hyperthermia. According to this hypothesis, somatic cell resilience determines and hyperthermia. We propose that cell resilience to somatic stressors incurred in inflamma- tion is important

de Magalhães, João Pedro

409

Assessing Executive Functions: A Life-Span Perspective  

ERIC Educational Resources Information Center

Despite many disagreements on the utility of neuropsychological applications in schools, executive function measures have been found to be useful across a variety of areas and ages. In addition, many disagreements are extant in discussions of the maturational course of the development of executive functioning abilities that are dependent on

Reynolds, Cecil R.; Horton, Arthur MacNeill, Jr.

2008-01-01

410

Growth and Development through the Life Span. Teacher Edition.  

ERIC Educational Resources Information Center

This curriculum guide is designed to prepare nursing professionals to assess clients' needs and help both the doctor and clients. The guide contains seven units. Unit 1 introduces the basic concepts of growth and development that the student will need to understand as a basis for the remaining units. Each of the remaining six units discusses

Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

411

Effects of calorie restriction on life span of microorganisms  

E-print Network

CR, increases both respiration and cellular resistance to aaerobic respiration represents the vast majority of cellularcellular and nuclear NADH, enforced by a metabolic shift to mitochondrial respiration,

Skinner, Craig; Lin, Su-Ju

2010-01-01

412

Life-span knowledge engineering for space operations  

NASA Technical Reports Server (NTRS)

Ordinarily, knowledge engineering is thought of as the process of translating the knowledge and problem solving strategies of a human expert into rules and procedures incorporated into a machine based expert system which can, given adequate input, solve the same sorts of problems as the expert. One appeal of these knowledge based systems is their ability to take care of problems without having a human expert present. For work in space, being independent of humans is especially important both for situations where devices will be in remote or dangerous locales and for situations such as space stations where human resources are limited and schedules are tight. In qualification of the above ideas, it is argued herein that the notion of knowledge engineering and the expectations for its application should be extended beyond the period of construction of unit expert systems to the entire knowledge system management associated with one or another real systems, whether it is a piece of hardware or an entire human-machine operation such as a lunar factory.

Hays, Dan

1988-01-01

413

Telomere Model Predicts Cell Life Span | Physical Sciences in Oncology  

Cancer.gov

Using a sophisticated mathematical model describing the biophysics of the ends of chromosomes, researchers at New York University's Courant School of Mathematics have shown they can describe how changes in the spatial organization of structures known as telomeres affect the lifespan of a cell.

414

Families as Nurturing Systems: Support across the Life Span.  

ERIC Educational Resources Information Center

This volume seeks to refine and extend knowledge about approaches to supporting the caregiving roles of families. The chapters in the volume describe and appraise new directions in family support. After an introduction, the two parts of the volume address "New Directions for Family Resource and Support Programs" (six chapters) and "Family Support

Unger, Donald G., Ed.; Powell, Douglas R., Ed.

415

Patterns of Learning. New Perspectives on Life-Span Education.  

ERIC Educational Resources Information Center

Basic methods of learning, most of which have been used through centuries of recorded thought, are discussed, along with learning as a lifelong process, and ways to enhance and diversify modern education. Numerous learning processes are studied by examining the lives of great individuals who have exemplified innovative and multifaceted approaches

Houle, Cyril O.

416

Effects of calorie restriction on life span of microorganisms  

Microsoft Academic Search

Calorie restriction (CR) in microorganisms such as budding and fission yeasts has a robust and well-documented impact on longevity.\\u000a In order to efficiently utilize the limited energy during CR, these organisms shift from primarily fermentative metabolism\\u000a to mitochondrial respiration. Respiration activates certain conserved longevity factors such as sirtuins and is associated\\u000a with widespread physiological changes that contribute to increased survival.

Craig Skinner; Su-Ju Lin

2010-01-01

417

Life span extension and cancer risk: myths and reality  

Microsoft Academic Search

A significant increase in the number of old people in the populations of developed countries was followed by an increase in morbidity and mortality resulting from main age-related diseases cardiovascular, cancer, neurodegenerative, diabetes mellitus, decrease in resistance to infections. Obviously, the development of the means of prevention of the premature aging of humans is crucial for the realization of

Vladimir N. Anisimov

2001-01-01

418

Memory Plasticity across the Life Span: Uncovering Children's Latent Potential  

ERIC Educational Resources Information Center

Memory plasticity, or the ability to improve one's memory performance through instruction and training, is known to decline during adulthood. However, direct comparisons among middle childhood, adulthood, and old age are lacking. The authors examined memory plasticity in an age-comparative multisession training study. One hundred and eight

Brehmer, Yvonne; Li, Shu-Chen; Muller, Viktor; von Oertzen, Timo; Lindenberger, Ulman

2007-01-01

419

Programming the body, planning reproduction, governing life: the '(ir-) rationality' of family planning and the embodiment of social inequalities in Salvador da Bahia (Brazil).  

PubMed

This paper examines family planning in Brazil as biopolitics and explores how the democratization of the State and of reproductive health services after two decades of military dictatorship (1964-1984) has influenced health professionals' and family planning users' discourses and practices. Do health professionals envisage family planning as a 'right' or do they conceive it, following the old neo-Malthusian rationale, as a 'moral duty' of poor people, whose 'irrational' reproduction jeopardizes the family's and the nation's well being? And how do their patients conceptualize and embody family planning? To answer these questions, this paper draws on 13 months of multi-sited ethnographic research undertaken between 2003 and 2005 in two public family planning services in Salvador da Bahia, where participant observation was undertaken and unstructured interviews were conducted with 11 health professionals and 70 family planning users, mostly low income black women. The paper examines how different bio-political rationalities operate in these services and argues that the old neo-Malthusian rationale and the current, dominant discourse on reproductive rights, gender equality and citizenship coexist. The coalescence of different biopolitical rationalities leads to the double stigmatization of family planning users as 'victims' of social and gender inequalities and as 'irrational' patients, 'irresponsible' mothers and 'bad' citizens if they do not embody the neo-Malthusian and biomedical rationales shaping medical practice. However, these women do not behave as 'docile bodies': they tactically use medical and non-medical contraceptives not only to be good mothers and citizens, but also to enhance themselves and to attain their own goals. PMID:22889428

De Zordo, Silvia

2012-01-01

420

Maintaining Spanning Trees of Small Diameter  

Microsoft Academic Search

Given a graph G with m edges and n nodes, a spanning tree T of G, and an edge e that is being deleted from or inserted into G, we give efficient O(n) algorithms to compute a possible swap for e that minimizes the diameter of the new spanning tree. This problem arises in high-speed networks, particularly in optical networks.

Giuseppe F. Italiano; Rajiv Ramaswami

1994-01-01

421

P300 Latency and Memory Span Development.  

ERIC Educational Resources Information Center

Digit span and latency from P300 component of event-related brain potential--a measure of stimulus evaluation time--were obtained from children and adults. Increases in digit span were associated with decreases in peak latency for children but not adults, suggesting that immediate memory development is tightly coupled with decreases in speed of

Howard, Lawrence; Polich, John

1985-01-01

422

Using age-based life history data to investigate the life cycle and vulnerability of Octopus cyanea.  

PubMed

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

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

2012-01-01

423

Reproductive strategies of Atlantic salmon: ecology and evolution  

Microsoft Academic Search

Atlantic salmon (Salmo solar, Salmonidae) show a diversity of life history, behavioural and morphological adaptations for reproduction which have evolved as an outcome of competition to maximize reproductive success. Reproductive traits of females have been shaped principally by natural selection for offspring production and survival, those of males by sexual selection for access to matings. Female Atlantic salmon invest approximately

Ian A. Fleming

1996-01-01

424

Seabed irregularity in subsea pipeline spanning  

SciTech Connect

This paper presents an analytical method and investigation results of subsea pipelines span/stress/strain/deflection determinations for a pipeline laying on an irregular bottom. Parameters of interest are calculated for the pipeline immediately after laying (installation conditions) and also for operational loads. Investigated operational loads are pipeline contents weight, pipeline internal and external pressure. Computer software to calculate pipeline spanning parameters have been developed in practical engineering form and a sample is presented in the paper. An original mathematical model for the span system is presented in this paper. Predicted pipe spans/axial tensions are the initial data to investigate sea current influence yielding span length limits due to pipeline lateral vibrations induced by resonant vortex shedding. The analytical method and procedure may be used to assist selection of subsea pipeline routes.

Kershenbaum, N.Y.; Harrison, G.E. [Hudson Engineering Corp., Houston, TX (United States)

1995-12-31

425

Evolution of reproductive isolation as a by-product of divergent life-history evolution in laboratory populations of Drosophila melanogaster  

PubMed Central

We show that two complementary asymmetric isolating mechanisms, likely mediated by divergence in body size, underlie the evolution of incipient reproductive isolation between a set of Drosophila melanogaster populations selected for rapid development and their ancestral controls. Selection has led to great reduction in body size in the fast developing lines. Small males belonging to fast developing lines obtain few matings with large control females, both in presence and absence of large control line males, giving rise to unidirectional, premating isolation caused by sexual selection. Conversely, small selected line females suffer greatly increased mortality following mating with large control males, causing unidirectional postcopulatory prezygotic isolation. We discuss preliminary evidence for evolution of reduced male harm caused to females upon mating in the fast developing lines, and speculate that the females from these lines have coevolved reduced resistance to male harm such that they can no longer resist the harm caused by males from control lines. This potentially implicates differing levels of sexual conflict in creating reproductive barrier between the selected line females and the control males. We also show that a large difference in development time is not sufficient to cause postzygotic incompatibilities in the two sets of populations reaffirming the belief that prezygotic isolation can evolve much earlier than postzygotic isolation. PMID:23301185

M Ghosh, Shampa; Joshi, Amitabh

2012-01-01

426

Current Development in Reproductive Toxicity Testing of Pesticides  

EPA Science Inventory

A protocol to evaluate the potential developmental and reproductive effects of test chemicals has been developed by the Life Stages Task Force of the International Life Sciences Institute (ILSI)/Health and Environmental Sciences Institute (HESI) Agricultural Chemical Safety Asses...

427

Infectious Diseases, Reproductive Effort and the Cost of Reproduction in Birds  

Microsoft Academic Search

Reproductive effort can have profound effects on subsequent performance. Field experiments on the collared flycatcher (Ficedula albicollis) have demonstrated a number of trade-offs between life-history traits at different ages. The mechanism by which reproductive effort is mediated into future reproductive performance remains obscure. Anti-parasite adaptations such as cell-mediated immunity may probably also be costly. Hence the possibility exists of a

L. Gustafsson; D. Nordling; M. S. Andersson; B. C. Sheldon; A. Qvarnstrom

1994-01-01

428

Developmental patterns of verbal and visuospatial spans.  

PubMed

This study presents developmental data for verbal and spatial memory tasks: Corsi's block-tapping test and Luria's verbal learning test. Norms have been collected from 275 primary and early secondary school children aged from 5 years, 4 months to 13 years, 6 months. Our results confirm a slow and constant improvement in performances over time, and the advantage of about 1.5 items of the verbal span over the spatial span supports the existence of developmental differences between separate memory systems. No significant sex difference was found even if a slight trend in verbal span favouring female subjects is present. PMID:11917975

Nichelli, F; Bulgheroni, S; Riva, D

2001-10-01

429

Individual variation in reproductive costs of reproduction: high-quality females always do better.  

PubMed

1. Although life-history theory predicts substantial costs of reproduction, individuals often show positive correlations among life-history traits, rather than trade-offs. The apparent absence of reproductive costs may result from heterogeneity in individual quality. 2. Using detailed longitudinal data from three contrasted ungulate populations (mountain goats, Oreamnos americanus; bighorn sheep, Ovis canadensis; and roe deer, Capreolus capreolus), we assessed how individual quality affects the probability of detecting a cost of current reproduction on future reproduction for females. We used a composite measure of individual quality based on variations in longevity (all species), success in the last breeding opportunity before death (goats and sheep), adult mass (all species), and social rank (goats only). 3. In all species, high-quality females consistently had a higher probability of reproduction, irrespective of previous reproductive status. In mountain goats, we detected a cost of reproduction only after accounting for differences in individual quality. Only low-quality female goats were less likely to reproduce following years of breeding than of nonbreeding. Offspring survival was lower in bighorn ewes following years of successful breeding than after years when no lamb was produced, but only for low-quality females, suggesting that a cost of reproduction only occurred for low-quality females. 4. Because costs of reproduction differ among females, studies of life-history evolution must account for heterogeneity in individual quality. PMID:18700872

Hamel, Sandra; Ct, Steeve D; Gaillard, Jean-Michel; Festa-Bianchet, Marco

2009-01-01

430

The productive and reproductive biology of flowering plants  

Microsoft Academic Search

The life cycles, programme of energy expenditure and allocation to reproduction, and the reproductive efforts of three wildAllium species, i.e.,A. Victorialis ssp.platyphyllum, A. monanthum, andA. Grayi, all native to Japan, were studied and compared. Furthermore, their adaptive strategies were discussed from the point of\\u000a view of life history strategy. First, the reproductive systems, number of male and female gametes borne,

Shoichi Kawano; Yukio Nagai

1975-01-01

431

Factorizations of some weighted spanning tree enumerators  

E-print Network

We give factorizations for weighted spanning tree enumerators of Cartesian products of complete graphs, keeping track of fine weights related to degree sequences and edge directions. Our methods combine Kirchhoff's ...

Martin, Jeremy L.; Reiner, Victor

2003-11-01

432

Manipulating reproductive effort leads to changes in female reproductive scheduling but not oxidative stress  

PubMed Central

The trade-off between reproductive investment and lifespan is the single most important concept in life-history theory. A variety of sources of evidence support the existence of this trade-off, but the physiological costs of reproduction that underlie this relationship remain poorly understood. The Free Radical Theory of Ageing suggests that oxidative stress, which occurs when there is an imbalance between the production of damaging Reactive Oxygen Species (ROS) and protective antioxidants, may be an important mediator of this trade-off. We sought to test this theory by manipulating the reproductive investment of female mice (Mus musculus domesticus) and measuring the effects on a number of life history and oxidative stress variables. Females with a greater reproductive load showed no consistent increase in oxidative damage above females who had a smaller