Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 155
Filtrar
1.
Public Health ; 159: 89-94, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29599056

RESUMO

OBJECTIVES: This article presents the findings of a project focusing on building evaluation capacity in 10 Ontario public health units. The study sought to identify effective strategies that lead to increased evaluation capacity in the participating organizations. STUDY DESIGN: This study used a qualitative, multiple case research design. METHODS: An action research methodology was used to design customized evaluation capacity building (ECB) strategies for each participating organization, based on its specific context and needs. This methodological approach also enabled monitoring and assessment of each strategy, based on a common set of reporting templates. A multiple case study was used to analyze the findings from the 10 participating organizations and derive higher level findings. RESULTS: The main findings of the study show that most of the strategies used to increase evaluation capacity in public health units are promising, especially those focusing on developing the knowledge, skills, and attitudes of health unit staff and managers. Facilitators to ECB strategies were the engagement of all staff members, the support of leadership, and the existence of organizational tools and infrastructure to support evaluation. It is also essential to recognize that ECB takes time and resources to be successful. CONCLUSIONS: The design and implementation of ECB strategies should be based on organizational needs. These can be assessed using a standardized instrument, as well as interviews and staff surveys. The implementation of a multicomponent approach (i.e. several strategies implemented simultaneously) is also linked to better ECB outcomes in organizations.


Assuntos
Fortalecimento Institucional/métodos , Administração em Saúde Pública , Prática de Saúde Pública , Pesquisa sobre Serviços de Saúde , Humanos , Ontário , Pesquisa Qualitativa
2.
Health Educ Res ; 33(1): 81-88, 2018 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-29309599

RESUMO

Text-based interventions are effective for smoking cessation, but have not been tested in rural older adults. The purpose of this study was to compare the feasibility, acceptability and preliminary efficacy of a text-based Scheduled Gradual Reduction (SGR) program to a non-SGR text messaging support condition among rural older adults. Adults over 60 years were randomized to either: (i) the SGR program (n = 20), a text-based program to reduce smoking over 4-weeks plus text-based support messages; or (ii) control (n = 20), receipt of text-based support messages only. Participants completed surveys at baseline and end of program to assess feasibility and acceptability of the intervention, and biochemically validated 7-day point prevalence cessation was assessed at end of treatment. Most participants (81%) reported reading all the messages they received. Participants found both interventions useful in quitting smoking (SGR = 57%, Control = 63%) and would recommend it to a friend (SGR = 72%, Control = 79%). Although not statically significant, the SGR group had a higher rate of biochemically validated cessation (SGR = 15%, Control = 5%, Cohen d = 0.67). Among those still smoking, the median percent reduction in cigarettes was 33.3% for both groups. Text-based cessation interventions are feasible, acceptable and can be easily disseminated to rural older adult tobacco users.


Assuntos
População Rural , Abandono do Hábito de Fumar/métodos , Envio de Mensagens de Texto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores Socioeconômicos , Fatores de Tempo
3.
J Evol Biol ; 31(1): 57-65, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29164722

RESUMO

Theory predicts a trade-off between sexually selected weapons used to secure mates and post-copulatory traits used to maximize fertilization success. However, individuals that have a greater capacity to acquire resources from the environment may invest more in both pre- and post-copulatory traits, and trade-offs may not be readily apparent. Here, we manipulate the phenotype of developing individuals to examine allocation trade-offs between weapons and testes in Mictis profana (Hemiptera: Coreidae), a species where the hind legs are sexually selected weapons used in contests over access to females. We experimentally prevented males from developing weapons by inducing them to autotomize their hind legs before the final moult to adulthood. We compared trait expression in this group to males where autotomy was induced in the mid-legs, which are presumably not under sexual selection to the same extent. We found males without weapons invested proportionally more in testes mass than those with their mid-legs removed. Males that developed to adulthood without weapons did not differ from the mid-leg removal group in other traits potentially under precopulatory sexual selection, other post-copulatory traits or naturally selected traits. In addition, a sample of adult males from the same population in the wild revealed a positive correlation between investment in testes and weapons. Our study presents a critical contribution to a growing body of literature suggesting the allocation of resources to pre- and post-copulatory sexual traits is influenced by a resource allocation trade-off and that this trade-off may only be revealed with experimental manipulation.


Assuntos
Hemípteros/anatomia & histologia , Hemípteros/fisiologia , Comportamento Sexual Animal/fisiologia , Testículo/anatomia & histologia , Animais , Evolução Biológica , Feminino , Masculino , Fenótipo , Seleção Genética
4.
J Evol Biol ; 30(9): 1763-1771, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28675768

RESUMO

Group living can select for increased immunity, given the heightened risk of parasite transmission. Yet, it also may select for increased male reproductive investment, given the elevated risk of female multiple mating. Trade-offs between immunity and reproduction are well documented. Phenotypically, population density mediates both reproductive investment and immune function in the Indian meal moth, Plodia interpunctella. However, the evolutionary response of populations to these traits is unknown. We created two replicated populations of P. interpunctella, reared and mated for 14 generations under high or low population densities. These population densities cause plastic responses in immunity and reproduction: at higher numbers, both sexes invest more in one index of immunity [phenoloxidase (PO) activity] and males invest more in sperm. Interestingly, our data revealed divergence in PO and reproduction in a different direction to previously reported phenotypic responses. Males evolving at low population densities transferred more sperm, and both males and females displayed higher PO than individuals at high population densities. These positively correlated responses to selection suggest no apparent evolutionary trade-off between immunity and reproduction. We speculate that the reduced PO activity and sperm investment when evolving under high population density may be due to the reduced population fitness predicted under increased sexual conflict and/or to trade-offs between pre- and post-copulatory traits.


Assuntos
Densidade Demográfica , Reprodução , Comportamento Sexual Animal , Animais , Evolução Biológica , Feminino , Masculino , Mariposas , Fenótipo , Espermatozoides
5.
J Evol Biol ; 29(8): 1535-52, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27159063

RESUMO

When females mate polyandrously, male reproductive success depends both on the male's ability to attain matings and on his ability to outcompete rival males in the fertilization of ova post-copulation. Increased investment in  ejaculate components may trade off with investment in precopulatory traits due to resource allocation. Alternatively, pre- and post-copulatory traits could be positively related if individuals can afford to invest heavily in traits advantageous at both episodes of selection. There is empirical evidence for both positive and negative associations between pre- and post-copulatory episodes, but little is known about the genetic basis of these correlations. In this study, we measured morphological, chemical and behavioural precopulatory male traits and investigated their relationship with measures of male fitness (male mating success, remating inhibition and offensive sperm competitiveness) across 40 isofemale lines of Drosophila melanogaster. We found significant variation among isofemale lines, indicating a genetic basis for most of the traits investigated. However, we found weak evidence for genetic correlations between precopulatory traits and our indices of male fitness. Moreover, pre- and post-copulatory episodes of selection were uncorrelated, suggesting selection may act independently at the different episodes to maximize male reproductive success.


Assuntos
Copulação , Drosophila melanogaster/genética , Variação Genética , Animais , Feminino , Masculino , Reprodução , Seleção Genética , Comportamento Sexual Animal
6.
J Evol Biol ; 29(5): 916-28, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26801640

RESUMO

Polyandry is widespread despite its costs. The sexually selected sperm hypotheses ('sexy' and 'good' sperm) posit that sperm competition plays a role in the evolution of polyandry. Two poorly studied assumptions of these hypotheses are the presence of additive genetic variance in polyandry and sperm competitiveness. Using a quantitative genetic breeding design in a natural population of Drosophila melanogaster, we first established the potential for polyandry to respond to selection. We then investigated whether polyandry can evolve through sexually selected sperm processes. We measured lifetime polyandry and offensive sperm competitiveness (P2 ) while controlling for sampling variance due to male × male × female interactions. We also measured additive genetic variance in egg-to-adult viability and controlled for its effect on P2 estimates. Female lifetime polyandry showed significant and substantial additive genetic variance and evolvability. In contrast, we found little genetic variance or evolvability in P2 or egg-to-adult viability. Additive genetic variance in polyandry highlights its potential to respond to selection. However, the low levels of genetic variance in sperm competitiveness suggest that the evolution of polyandry may not be driven by sexy sperm or good sperm processes.


Assuntos
Variação Genética , Comportamento Sexual Animal , Espermatozoides/fisiologia , Animais , Evolução Biológica , Drosophila melanogaster/genética , Feminino , Masculino
8.
Plant Cell ; 27(11): 3065-80, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26546445

RESUMO

The best-characterized members of the plant-specific SIAMESE-RELATED (SMR) family of cyclin-dependent kinase inhibitors regulate the transition from the mitotic cell cycle to endoreplication, also known as endoreduplication, an altered version of the cell cycle in which DNA is replicated without cell division. Some other family members are implicated in cell cycle responses to biotic and abiotic stresses. However, the functions of most SMRs remain unknown, and the specific cyclin-dependent kinase complexes inhibited by SMRs are unclear. Here, we demonstrate that a diverse group of SMRs, including an SMR from the bryophyte Physcomitrella patens, can complement an Arabidopsis thaliana siamese (sim) mutant and that both Arabidopsis SIM and P. patens SMR can inhibit CDK activity in vitro. Furthermore, we show that Arabidopsis SIM can bind to and inhibit both CDKA;1 and CDKB1;1. Finally, we show that SMR2 acts to restrict cell proliferation during leaf growth in Arabidopsis and that SIM, SMR1/LGO, and SMR2 play overlapping roles in controlling the transition from cell division to endoreplication during leaf development. These results indicate that differences in SMR function in plant growth and development are primarily due to differences in transcriptional and posttranscriptional regulation, rather than to differences in fundamental biochemical function.


Assuntos
Sequência Conservada , Proteínas Inibidoras de Quinase Dependente de Ciclina/metabolismo , Embriófitas/metabolismo , Família Multigênica , Proteínas de Plantas/metabolismo , Sequência de Aminoácidos , Arabidopsis/metabolismo , Fenômenos Biomecânicos , Morte Celular , Proliferação de Células , Embriófitas/genética , Endorreduplicação , Técnicas de Inativação de Genes , Teste de Complementação Genética , Dados de Sequência Molecular , Mutação/genética , Fenótipo , Filogenia , Folhas de Planta/citologia , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/ultraestrutura , Proteínas de Plantas/genética , Ligação Proteica , Protoplastos/metabolismo , Tricomas/citologia , Tricomas/metabolismo , Tricomas/ultraestrutura
9.
J Evol Biol ; 28(12): 2187-95, 2015 12.
Artigo em Inglês | MEDLINE | ID: mdl-26332435

RESUMO

Male ornaments and armaments that mediate success in mate acquisition and ejaculate traits influencing competitive fertilization success are under intense sexual selection. However, relative investment in these pre- and post-copulatory traits depends on the relative importance of either selection episode and on the energetic costs and fitness gains of investing in these traits. Theoretical and empirical work has improved our understanding of how precopulatory sexual traits and investments in sperm production covary in this context. It has recently also been suggested that male weapon size may trade off with sperm length as another post-copulatory sexual trait, but the theoretical framework for this suggestion remains unclear. We evaluated the relationship between precopulatory armaments and sperm length, previously reported in ungulates, in five taxa as well as meta-analytically. Within and between taxa, we found no evidence for a negative or positive relationship between sperm length and male traits that are important in male-male contest competition. It is important to consider pre- and post-copulatory sexual selection together to understand fitness, and to study investments in different reproductive traits jointly rather than separately. A trade-off between pre- and post-copulatory sexual traits may not manifest itself in sperm length but rather in sperm number or function. Particularly in large-bodied taxa such as ungulates, sperm number is more variable interspecifically and likely to be under more intense selection than sperm length. We discuss our and the previous results in this context.


Assuntos
Comportamento Sexual Animal , Espermatozoides/citologia , Animais , Humanos , Masculino
10.
J Psychiatr Ment Health Nurs ; 22(9): 668-79, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26118332

RESUMO

ACCESSIBLE SUMMARY: The stigma of mental illness varies significantly from culture to culture and from person to person. To date, little is known about how mental illness stigma manifests within the Arab community. This study aimed at bringing clarity to the concept of 'mental illness stigma' as it applies to Arab families. Nursing's holistic and patient-centered approach is integral to helping Arab patients and their families appropriately incorporate individual values, beliefs, and cultural perspectives into treatment plans. This study establishes a scientific alert for professionals at all levels to avoid making false generalizations about a specific culture that are not based on specific research findings from that culture. ABSTRACT: Accessing mental health services is a critical step towards reducing the burden of mental illness. The stigma of mental illness is one of the most common reasons for not seeking mental health care leading to negative health consequences and undue suffering for many individuals and their families. Stigma is embedded in its social context. What may be considered acceptable in one society may be considered unacceptable and open to stigmatization in other societies. Arabs have a shared set of values, beliefs, and traditions that are substantially different from those of Westerners. Further, in most Arab countries, formal mental health resources are scarce and people with mental illness experience the compounded disadvantages of poverty and illness stigma. To date, little is known about how mental illness stigma manifests within the Arab community making it difficult to design and test interventions that support Arab individuals with mental illness and their families in treatment seeking and adherence. Using Rodger's concept analysis method, we examined how 'mental illness stigma' operates within an Arab context as a first step towards elucidating culturally competent approaches to treatment. This analysis provides a foundation for future work in the areas of mental illness diagnosis, education, and treatment that reflect the unique characteristics of Arab culture.


Assuntos
Árabes , Transtornos Mentais/etnologia , Estigma Social , Humanos , Pesquisa Qualitativa
11.
J Evol Biol ; 28(3): 730-8, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25736536

RESUMO

Males and females differ in their phenotypic optima for many traits, and as the majority of genes are expressed in both sexes, some alleles can be beneficial to one sex but harmful to the other (intralocus sexual conflict; ISC). ISC theory has recently been extended to intrasexual dimorphisms, where certain alleles may have opposite effects on the fitness of males of different morphs that employ alternative reproductive tactics (intralocus tactical conflict; ITC). Here, we use a half-sib breeding design to investigate the genetic basis for ISC and ITC in the dung beetle Onthophagus taurus. We found positive heritabilities and intersexual genetic correlations for almost all traits investigated. Next, we calculated the intrasexual genetic correlation between males of different morphs for horn length, a sexually selected trait, and compared it to intrasexual correlations for naturally selected traits in both sexes. Intrasexual genetic correlations did not differ significantly between the sexes or between naturally and sexually selected traits, failing to support the hypothesis that horns present a reduction of intrasexual genetic correlations due to ITC. We discuss the implications for the idea of developmental reprogramming between male morphs and emphasize the importance of genetic correlations as constraints for the evolution of dimorphisms.


Assuntos
Comportamento Animal/fisiologia , Besouros/genética , Animais , Evolução Biológica , Besouros/fisiologia , Feminino , Cornos/anatomia & histologia , Masculino , Locos de Características Quantitativas , Seleção Genética , Caracteres Sexuais
12.
J Evol Biol ; 27(10): 2249-57, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25228329

RESUMO

Female choice based on male secondary sexual traits is well documented, although the extent to which this selection can drive an evolutionary divergence in male traits among populations is less clear. Male field crickets Teleogryllus oceanicus attract females using a calling song and once contacted switch to courtship song to persuade them to mate. These crickets also secrete onto their cuticle a cocktail of long-chained fatty acids or cuticular hydrocarbons (CHCs). Females choose among potential mates based on the structure of male acoustic signals and on the composition of male CHC profiles. Here, we utilize two naturally occurring mutations that have arisen independently on two Hawaiian islands and render the male silent to ask whether the evolutionary loss of acoustic signalling can drive an evolutionary divergence in the alternative signalling modality, male CHC profiles. QST -FST comparisons revealed strong patterns of CHC divergence among three populations of crickets on the islands of Hawaii, Oahu and Kauai. Contrasts between wild-type and flatwing males on the islands of Oahu and Kauai indicated that variation in male CHC profiles within populations is associated with the loss of acoustic signalling; flatwing males had a relatively low abundance of long-chained CHCs relative to the short-chained CHCs that females find attractive. Given their dual functions in desiccation resistance and sexual signalling, insect CHCs may be particularly important traits for reproductive isolation and ultimately speciation.


Assuntos
Evolução Biológica , Gryllidae/genética , Hidrocarbonetos/química , Preferência de Acasalamento Animal , Vocalização Animal , Animais , Feminino , Gryllidae/anatomia & histologia , Havaí , Masculino , Mutação , Caracteres Sexuais
13.
J Evol Biol ; 27(8): 1644-9, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24836498

RESUMO

Competitive fertilization success can depend on the relative abilities of competing males to fertilize available ova, and on mechanisms of cryptic female choice that moderate paternity. Competitive fertilization success is thus an emergent property of competing male genotypes, female genotype and their interactions. Accurate estimates of intrinsic male effects on competitive fertilization success are therefore problematic. We used a cross-classified nonbreeding design in which rival male family background was standardized to partition variation in competitive fertilization success among male and female family backgrounds in the field cricket Teleogryllus oceanicus. Male effects were close to zero, supporting previous quantitative genetic designs in which male competitors were assigned at random. In contrast, some 22% of the variance in competitive fertilization success was explained by female effects, suggesting that paternity in this species is influenced strongly by cryptic female choice.


Assuntos
Gryllidae/fisiologia , Preferência de Acasalamento Animal/fisiologia , Espermatozoides/fisiologia , Animais , Comportamento Competitivo/fisiologia , Feminino , Fertilização/fisiologia , Genótipo , Modelos Lineares , Masculino , Repetições de Microssatélites/genética , Reação em Cadeia da Polimerase , Reprodução/fisiologia , Análise de Sequência de DNA , Austrália Ocidental
14.
J Evol Biol ; 27(6): 1020-8, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24750259

RESUMO

Trans-generational immune priming is the transmission of enhanced immunity to offspring following a parental immune challenge. Although within-generation increased investment into immunity demonstrates clear costs on reproductive investment in a number of taxa, the potential for immune priming to impact on offspring reproductive investment has not been thoroughly investigated. We explored the reproductive costs of immune priming in a field cricket, Teleogryllus oceanicus. To assess the relative importance of maternal and paternal immune status, mothers and fathers were immune-challenged with live bacteria or a control solution and assigned to one of four treatments in which one parent, neither or both parents were immune-challenged. Families of offspring were reared to adulthood under a food-restricted diet, and approximately 10 offspring in each family were assayed for two measures of immunocompetence. We additionally quantified offspring reproductive investment using sperm viability for males and ovary mass for females. We demonstrate that parental immune challenge has significant consequences for the immunocompetence and, in turn, reproductive investment of their male offspring. A complex interaction between maternal and paternal immune status increased the antibacterial immune response of male offspring. This increased immune response was associated with a reduction in son's sperm viability, implicating a trans-generational resource trade-off between investment into immunocompetence and reproduction. Our data also show that these costs are sexually dimorphic, as daughters did not demonstrate a similar increase in immunity, despite showing a reduction in ovary mass.


Assuntos
Gryllidae/imunologia , Animais , Feminino , Gryllidae/microbiologia , Masculino , Reprodução , Serratia marcescens
15.
J Evol Biol ; 27(1): 133-40, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24251540

RESUMO

Despite the ubiquitous nature of sperm storage in invertebrates, relatively little is known about its costs, or the impact that immune activation can have on a female's ability to maintain viable sperm stores. We explored the effects of an immune challenge on sperm storage under food-limited and ad libitum conditions in the field cricket, Teleogryllus oceanicus, by injecting mated adult females with either a LD5 dose of live bacteria or a nonpathogenic immune elicitor [lipopolysaccharide (LPS)] and then scoring the viability of their stored sperm. Females that were infected with bacteria showed a reduction in the viability of stored sperm 48 h after infection; interestingly, this pattern was not evident when females were injected with LPS. Reduction in sperm viability post-infection may reflect a reproductive trade-off between immune function and sperm store maintenance, as only females injected with bacteria showed an elevated antibacterial immune (lytic) response. Alternatively, bacteria may act directly on sperm quality. Dietary manipulations showed that lytic activity in females is condition dependent, irrespective of their immune challenge treatment. Diet affected the ability of females to maintain the viability of stored sperm, suggesting that sperm storage is condition dependent. That bacterial infection associated with a reduction in stored sperm quality has potentially important implications for the outcomes of sperm competition in T. oceanicus and in other species in which females store sperm between matings.


Assuntos
Gryllidae/imunologia , Espermatozoides/fisiologia , Animais , Dieta , Feminino , Gryllidae/crescimento & desenvolvimento , Masculino , Reprodução
16.
Mol Ecol ; 22(23): 5779-92, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24102888

RESUMO

Estimates of inbreeding and relatedness are commonly calculated using molecular markers, although the accuracy of such estimates has been questioned. As a further complication, in many situations, such estimates are required in populations with reduced genetic diversity, which is likely to affect their accuracy. We investigated the correlation between microsatellite- and pedigree-based coefficients of inbreeding and relatedness in laboratory populations of Drosophila melanogaster that had passed through bottlenecks to manipulate their genetic diversity. We also used simulations to predict expected correlations between marker- and pedigree-based estimates and to investigate the influence of linkage between loci and null alleles. Our empirical data showed lower correlations between marker- and pedigree-based estimates in our control (nonbottleneck) population than were predicted by our simulations or those found in similar studies. Correlations were weaker in bottleneck populations, confirming that extreme reductions in diversity can compromise the ability of molecular estimates to detect recent inbreeding events. However, this result was highly dependent on the strength of the bottleneck and we did not observe or predict any reduction in correlations in our population that went through a relatively severe bottleneck of N = 10 for one generation. Our results are therefore encouraging, as molecular estimates appeared robust to quite severe reductions in genetic diversity. It should also be remembered that pedigree-based estimates may not capture realized identity-by-decent and that marker-based estimates may actually be more useful in certain situations.


Assuntos
Drosophila melanogaster/genética , Genética Populacional/métodos , Endogamia , Modelos Genéticos , Animais , Simulação por Computador , Feminino , Ligação Genética , Variação Genética , Genótipo , Masculino , Repetições de Microssatélites , Linhagem
17.
Neuroscience ; 254: 120-9, 2013 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-24056195

RESUMO

Mild traumatic brain injury (mTBI) and post-traumatic stress disorder (PTSD) are pressing medical issues for the Warfighter. Symptoms of mTBI can overlap with those of PTSD, suggesting the possibility of a causal or mediating role of mTBI in PTSD. To address whether mTBI can exacerbate the neurobiological processes associated with traumatic stress, we evaluated the impact of mTBI from a blast overpressure (BOP) on the expression of a conditioned fear. In the rat, conditioned fear models are used to evaluate the emotional conditioning processes that are known to become dysfunctional in PTSD. Rats were first trained on a variable interval (VI), food maintained, operant conditioning task that established a general measure of performance. Inescapable electric shock (IES) was paired with an audio-visual conditioned stimulus (CS) and followed 1day later by three daily exposures to BOP (75kPa). Subsequently, the CS alone was presented once every 7days for 2months, beginning 4days following the last BOP. The CS was presented during the VI sessions allowing a concurrent measure of performance. Treatment groups (n=10, each group) received IES+BOP, IES+sham-BOP, sham-IES+BOP or sham-IES+sham-BOP. As expected, pairing the CS with IES produced a robust conditioned fear that was quantified by a suppression of responding on the VI. BOP significantly decreased the expression of the conditioned fear. No systematic short- or long-term performance deficits were observed on the VI from BOP. These results show that mTBI from BOP can affect the expression of a conditioned fear and suggests that BOP caused a decrease in inhibitory behavioral control. Continued presentation of the CS produced progressively less response suppression in both fear conditioned treatments, consistent with extinction of the conditioned fear. Taken together, these results show that mTBI from BOP can affect the expression of a conditioned fear but not necessarily in a manner that increases the conditioned fear or extends the extinction process.


Assuntos
Traumatismos por Explosões/fisiopatologia , Lesões Encefálicas/fisiopatologia , Condicionamento Operante/fisiologia , Medo/fisiologia , Esquema de Reforço , Animais , Traumatismos por Explosões/psicologia , Lesões Encefálicas/psicologia , Medo/psicologia , Masculino , Ratos , Ratos Sprague-Dawley , Fatores de Tempo
18.
J Evol Biol ; 26(6): 1261-8, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23745826

RESUMO

Recent evidence shows that females exert a post-copulatory fertilization bias in favour of unrelated males to avoid the genetic incompatibilities derived from inbreeding. One of the mechanisms suggested for fertilization biases in insects is female control over transport of sperm to the sperm-storage organs. We investigated post-copulatory inbreeding-avoidance mechanisms in females of the cricket Teleogryllus oceanicus. We assessed the relative contribution of related and unrelated males to the sperm stores of double-mated females. To demonstrate unequivocally that biased sperm storage results from female control rather than cryptic male choice, we manipulated the relatedness of mated males and of males performing post-copulatory mate guarding. Our results show that when guarded by a related male, females store less sperm from their actual mate, irrespective of the relatedness of the mating male. Our data support the notion that inhibition of sperm storage by female crickets can act as a form of cryptic female choice to avoid the severe negative effects of inbreeding.


Assuntos
Gryllidae/fisiologia , Comportamento Sexual Animal , Espermatozoides , Animais , Feminino , Masculino
19.
J Phys Condens Matter ; 25(25): 255401, 2013 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-23719192

RESUMO

Crystallization of amorphous Y67Fe33 into the YFe2 C15 Laves phase via a novel 'YFe' intermediate phase has been observed through to completion using time-resolved small angle neutron scattering (SANS). The nucleation and growth kinetics of the phase transformations have been studied at annealing temperatures below the crystallization temperatures for both the 'YFe' phase and the YFe2 phase. The SANS results agree with previously reported neutron diffraction and SANS data. At the annealing temperatures of 360, 370 and 380 °C, changes in the scattering intensity I(Q) occur as a result of the contrast between the amorphous matrix and the nucleating and growing Y and 'YFe' phases. Critical scattering occurs during each of the isotherms, relating to the full crystallization of Y67Fe33, and extrapolation gives a crystallization temperature of 382 °C. Beyond critical scattering, isotherms at 435, 450, and 465 °C reveal the details of the continuing transformation of the 'YFe' intermediate phase into the YFe2 C15 Laves phase.

20.
Obes Rev ; 14(2): 145-61, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23114034

RESUMO

The prevalence of obesity in America has reached epidemic proportions, and obesity among women is particularly concerning. Severe obesity (body mass index ≥35 kg m(-2) ) is more prevalent in women than men. Further, women have sex-specific risk factors that must be considered when developing preventive and therapeutic interventions. This review presents personalized medicine as a dynamic approach to obesity prevention, management and treatment for women. First, we review obesity as a complex health issue, with contributing sex-specific, demographic, psychosocial, behavioural, environmental, epigenetic and genetic/genomic risk factors. Second, we present personalized medicine as a rapidly advancing field of health care that seeks to quantify these complex risk factors to develop more targeted and effective strategies that can improve disease management and/or better minimize an individual's likelihood of developing obesity. Third, we discuss how personalized medicine can be applied in a clinical setting with current and emerging tools, including health risk assessments, personalized health plans, and strategies for increasing patient engagement. Finally, we discuss the need for additional research, training and policy that can enhance the practice of personalized medicine in women's obesity, including further advancements in the '-omics' sciences, physician training in personalized medicine, and additional development and standardization of innovative targeted therapies and clinical tools.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Política de Saúde , Obesidade/prevenção & controle , Medicina de Precisão/métodos , Pesquisa Biomédica , Feminino , Humanos , Política Nutricional , Obesidade/epidemiologia , Obesidade/terapia , Estados Unidos/epidemiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...