317 research outputs found

    Fine-scale genetic structure analyses suggest further male than female dispersal in mountain gorillas

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    BACKGROUND: Molecular studies in social mammals rarely compare the inferences gained from genetic analyses with field information, especially in the context of dispersal. In this study, we used genetic data to elucidate sex-specific dispersal dynamics in the Virunga Massif mountain gorilla population (Gorilla beringei beringei), a primate species characterized by routine male and female dispersal from stable mixed-sex social groups. Specifically, we conducted spatial genetic structure analyses for each sex and linked our genetically-based observations with some key demographic and behavioural data from this population. RESULTS: To investigate the spatial genetic structure of mountain gorillas, we analysed the genotypes of 193 mature individuals at 11 microsatellite loci by means of isolation-by-distance and spatial autocorrelation analyses. Although not all males and females disperse, female gorillas displayed an isolation-by-distance pattern among groups and a signal of dispersal at short distances from their natal group based on spatial autocorrelation analyses. In contrast, male genotypes were not correlated with spatial distance, thus suggesting a larger mean dispersal distance for males as compared to females. Both within sex and mixed-sex pairs were on average genetically more related within groups than among groups. CONCLUSIONS: Our study provides evidence for an intersexual difference in dispersal distance in the mountain gorilla. Overall, it stresses the importance of investigating spatial genetic structure patterns on a sex-specific basis to better understand the dispersal dynamics of the species under investigation. It is currently poorly understood why some male and female gorillas disperse while others remain in the natal group. Our results on average relatedness within and across groups confirm that groups often contain close relatives. While inbreeding avoidance may play a role in driving female dispersal, we note that more detailed dyadic genetic analyses are needed to shed light on the role of inbreeding avoidance as an ultimate cause of female dispersal in mountain gorillas

    Dispersal and reproductive careers of male mountain gorillas in Bwindi Impenetrable National Park, Uganda

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    Dispersal is a key event in the life of an animal and it influences individual reproductive success. Male mountain gorillas exhibit both philopatry and dispersal, resulting in a mixed one-male and multimale social organization. However, little is known about the relationship between male dispersal or philopatry and reproductive careers in Bwindi mountain gorillas. Here we analyze data spanning from 1993 to 2017 on social groups in Bwindi Impenetrable National Park, Uganda to examine the proportion of males that disperse, age of dispersal, pathways to attaining alpha status, fate of dispersing males and philopatric males, and male tenure length as well as make comparisons of these variables to the Virunga mountain gorilla population. We report previously undocumented cases of dispersal by immature males and old males and we also observed the only known case of a fully mature male immigrating into a breeding group. We used genetic tracking of known individuals to estimate that a minimum of 25% of males that disperse to become solitary males eventually form new groups. No differences were found between the Bwindi and Virunga population in the age of male dispersal, the proportion of males that disperse, the age of alpha male acquisition, and dominance tenure length. The lack of differences may be due to small sample sizes or because the observed ecological variability does not lead to life history differences between the populations. Males in both populations follow variable strategies to attain alpha status leading to the variable one-male and multimale social organization, including dispersal to become solitary and eventually form a group, via group fissioning, usurping another alpha male, or inheriting the alpha position when a previous group leader dies

    Solução glicosada hipertônica no mesentério e no peritônio de ratos: estudo macroscópico e microscópico

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    PURPOSE: The objective of the experimental study is to detect the macroscopic and microscopic alterations of the mesenterium and parietal peritoneum when hypertonic glucose aqueous solution 10%-25% is administrated into the peritoneal cavity of the rat. METHODS: 90 Wistar females young rats adults were used weighin between 180-250 g, numbered 1 to 90, establishing unique group and divided in three groups (A, B, C) of 30 animals chosen aleatory manner. 0,9% saline solution was used called control group, or group A, 10% glucose solution named group B, and in the others 30 was used 25% glucose solution named group C, differing in the observation period, (06h, 24h and 48h), but with the same procedure. A midline abdominal wall laparotomy was made and in the animals of the control group was injected 2 ml of a 0,9% saline solution into the peritoneal cavity. After, we made a suture in mass without to include the peritoneum. For the others groups (B, C) the rats received 10% glucose solution and 25% glucose solution injected into the peritoneal cavity respectively. All groups were kept under observation and the results were submitted to statistical analysis by a longitudinal and transversal comparative study. RESULTS: A new surgery was done in 6h, 24h and 48h, and we observed in macroscopic evaluation, the presence of fluid, serous uniforme and rosy all over the cavity. Vascular congestion was present. We dried out 90 fragments of mesenterium and 90 fragments of parietal peritonium bilateral. In the microscopic study, necrosis was not present. For the mesenterium histological study we observed 16 cases (17,8%) unspecific chronic inflammation, 30 cases (33,4%) hiperplasic linfonod, 10 cases (11,1%) high vascular congestion, 6 cases (6,6%) reaction fibrosis and 28 cases (31,1%) no alteration. For the parietal peritonium histological study we observed 6 cases (3,3%) reaction fibrosis and 174 cases (96,7%) no alteration. Giant cell was not present. In the statistical analisys statistic there is no significance between the groups (p>0,05). CONCLUSION: Hypertonic glucose solution and NaCl 0,9% on the mesenterium and parietal peritonium do not produce tissue necrosis in a rat and the inflammation process has the same intensity.OBJETIVO: Investigar as alterações macroscópicas e microscópicas do mesentério e do peritônio parietal quando se administra a solução aquosa de glicose hipertônica a 10% e a 25% na cavidade peritoneal de rato. MÉTODOS: 90 ratos fêmeas (n=90), adultos, Wistar, jovens, com peso variando de 180 a 250 gramas foram divididos em 3 sub-grupos (A, B e C) contendo cada um 30 animais com procedimentos idênticos, diferindo apenas no período de observação. Os números de 1 a 30 constituem o grupo A ou grupo-controle (NaCl 0,9%), os números de 31 a 60 constituem o grupo B ou grupo-glicose a 10% e os números de 61 a 90 constituem o grupo C ou grupo- glicose a 25%. Realizando-se posteriormente laparotomia com incisão mediana longitudinal de pele a 2 cm abaixo do processo Xiphoideus sterni, estendendo-se por 3 cm caudalmente na linha média ventral. A escolha do procedimento a ser realizado para introdução na cavidade peritoneal de 2 ml de uma solução de cloreto de sódio 0,9% (controle), de glicose hipertônica a 10% e de glicose hipertônica a 25%. Em períodos correspondentes às 6h, 24h e 48h de pós-operatório, os animais de cada grupo foram reoperados, sendo realizada avaliação macroscópica e microscópica além dos registros das alterações histológicas do mesentério e peritônio parietal. RESULTADOS: Na microscopia do mesentério observou-se que 30 animais (33,4%) apresentaram linfonodos hiperplásicos; 6 animais (6,6%) com fibrose reacional; 10 animais (11,1%) com intensa congestão vascular; 16 animais (17,8%) com inflamação crônica inespecífica; 28 casos (31,1%) sem alteração. A microscopia do peritônio revelou 6 casos com fibrose reacional (3,3%) 174 casos (96,7%) sem alteração histológica. CONCLUSÃO: As soluções de glicose a 10% e a 25% não causam necrose tecidual quando introduzidas na cavidade peritoneal. O processo reacional inflamatório é de igual intensidade tecidual comparando-se ao uso da solução de NaCl a 0,9%.UNCISAL DepartmentUFAL Morphology Department and Human AnatomyUNIFESP-EPM Surgery DepartmentUNIFESP, EPM, Surgery DepartmentSciEL

    Serum methylarginines and spirometry-measured lung function in older adults

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    Rationale: Methylarginines are endogenous nitric oxide synthase inhibitors that have been implicated in animal models of lung disease but have not previously been examined for their association with spirometric measures of lung function in humans. Objectives: This study measured serum concentrations of asymmetric and symmetric dimethylarginine in a representative sample of older community-dwelling adults and determined their association with spirometric lung function measures. Methods: Data on clinical, lifestyle, and demographic characteristics, methylated arginines, and L-arginine (measured using LC-MS/MS) were collected from a population-based sample of older Australian adults from the Hunter Community Study. The five key lung function measures included as outcomes were Forced Expiratory Volume in 1 second, Forced Vital Capacity, Forced Expiratory Volume in 1 second to Forced Vital Capacity ratio, Percent Predicted Forced Expiratory Volume in 1 second, and Percent Predicted Forced Vital Capacity. Measurements and Main Results: In adjusted analyses there were statistically significant independent associations between a) higher asymmetric dimethylarginine, lower Forced Expiratory Volume in 1 second and lower Forced Vital Capacity; and b) lower L-arginine/asymmetric dimethylarginine ratio, lower Forced Expiratory Volume in 1 second, lower Percent Predicted Forced Expiratory Volume in 1 second and lower Percent Predicted Forced Vital Capacity. By contrast, no significant associations were observed between symmetric dimethylarginine and lung function. Conclusions: After adjusting for clinical, demographic, biochemical, and pharmacological confounders, higher serum asymmetric dimethylarginine was independently associated with a reduction in key measures of lung function. Further research is needed to determine if methylarginines predict the decline in lung function

    Proteinuria, CrCl, and Immune Activation in Antiretroviral-Naïve HIV-Infected Subjects

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    Because both renal disease and immune activation predict progression to AIDS, we evaluated the relationships between dipstick proteinuria ≥1+ [7% of 1012 subjects], CrCl <90mL/min [18% of 1071 subjects], and percentages of peripheral activated CD8 cells (CD8+CD38+HLA-DR+) in antiretroviral-naïve, HIV-infected subjects enrolled into AIDS Clinical Trials Group studies 384 and A5095. Proteinuria, but not CrCl, was associated with higher percentages of CD8+CD38+HLA-DR+ cells [55% vs. 50%; P=0.01], with even more pronounced differences in men and among Blacks and Hispanics. Proteinuria may be a surrogate measure of greater immune activation in HIV-infected patients initiating antiretroviral therapy

    Catastrophic Decline of World's Largest Primate: 80% Loss of Grauer's Gorilla (Gorilla beringei graueri) Population Justifies Critically Endangered Status

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    Grauer's gorilla (Gorilla beringei graueri), the World's largest primate, is confined to eastern Democratic Republic of Congo (DRC) and is threatened by civil war and insecurity. During the war, armed groups in mining camps relied on hunting bushmeat, including gorillas. Insecurity and the presence of several militia groups across Grauer's gorilla's range made it very difficult to assess their population size. Here we use a novel method that enables rigorous assessment of local community and ranger-collected data on gorilla occupancy to evaluate the impacts of civil war on Grauer's gorilla, which prior to the war was estimated to number 16,900 individuals. We show that gorilla numbers in their stronghold of Kahuzi- Biega National Park have declined by 87%. Encounter rate data of gorilla nests at 10 sites across its range indicate declines of 82-100% at six of these sites. Spatial occupancy analysis identifies three key areas as the most critical sites for the remaining populations of this ape and that the range of this taxon is around 19,700 km2. We estimate that only 3,800 Grauer's gorillas remain in the wild, a 77% decline in one generation, justifying its elevation to Critically Endangered status on the IUCN Red List of Threatened Species

    Human antigen R as a therapeutic target in pathological cardiac hypertrophy

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    RNA binding proteins represent an emerging class of proteins with a role in cardiac dysfunction. We show that activation of the RNA binding protein human antigen R (HuR) is increased in the failing human heart. To determine the functional role of HuR in pathological cardiac hypertrophy, we created an inducible cardiomyocyte-specific HuR-deletion mouse and showed that HuR deletion reduces left ventricular hypertrophy, dilation, and fibrosis while preserving cardiac function in a transverse aortic constriction (TAC) model of pressure overload-induced hypertrophy. Assessment of HuR-dependent changes in global gene expression suggests that the mechanistic basis for this protection occurs through a reduction in fibrotic signaling, specifically through a reduction in TGF-β (Tgfb) expression. Finally, pharmacological inhibition of HuR at a clinically relevant time point following the initial development of pathological hypertrophy after TAC also yielded a significant reduction in pathological progression, as marked by a reduction in hypertrophy, dilation, and fibrosis and preserved function. In summary, this study demonstrates a functional role for HuR in the progression of pressure overload-induced cardiac hypertrophy and establishes HuR inhibition as a viable therapeutic approach for pathological cardiac hypertrophy and heart failure

    Incrementally Closing Octagons

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    The octagon abstract domain is a widely used numeric abstract domain expressing relational information between variables whilst being both computationally efficient and simple to implement. Each element of the domain is a system of constraints where each constraint takes the restricted form ±xi±xj≤c. A key family of operations for the octagon domain are closure algorithms, which check satisfiability and provide a normal form for octagonal constraint systems. We present new quadratic incremental algorithms for closure, strong closure and integer closure and proofs of their correctness. We highlight the benefits and measure the performance of these new algorithms
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