Importance of proton drip-line nuclei to nuclear astrophysics / Importancia de la línea de goteo de los protones de los núcleos para la astrofísica nuclear

Abstract We discuss recent results on decay of exotic proton rich nuclei at the proton drip line with Z<50, that are of great importance for nuclear astrophysics models.

Resumen Discutimos los resultados recientes sobre la desintegración de los núcleos exóticos ricos en protones en la línea de goteo de protones con Z <50, que son de gran importancia para los modelos de astrofísica nuclear.

Parabolic variation in sexual selection intensity across the range of a cold-water pipefish: implications for susceptibility to climate change.

While an understanding of evolutionary processes in shifting environments is vital in the context of rapid ecological change, one of the most potent selective forces, sexual selection, remains curiously unexplored. Variation in sexual selection across a species range, especially across a gradient of temperature regimes, has the potential to provide a window into the possible impacts of climate change on the evolution of mating patterns. Here, we investigated some of the links between temperature and indicators of sexual selection, using a cold-water pipefish as model. We found that populations differed with respect to body size, length of the breeding season, fecundity, and sexual dimorphism across a wide latitudinal gradient. We encountered two types of latitudinal patterns, either linear, when related to body size, or parabolic in shape when considering variables related to sexual selection intensity, such as sexual dimorphism and reproductive investment. Our results suggest that sexual selection intensity increases toward both edges of the distribution and that the large differences in temperature likely play a significant role. Shorter breeding seasons in the north and reduced periods for gamete production in the south certainly have the potential to alter mating systems, breeding synchrony, and mate monopolization rates. As latitude and water temperature are tightly coupled across the European coasts, the observed patterns in traits related to sexual selection can lead to predictions regarding how sexual selection should change in response to climate change. Based on data from extant populations, we can predict that as the worm pipefish moves northward, a wave of decreasing selection intensity will likely replace the strong sexual selection at the northern range margin. In contrast, the southern populations will be followed by heightened sexual selection, which may exacerbate the problem of local extinction at this retreating boundary.

Apoptosis differentially regulates mesenteric and subcutaneous lymph node immune responses to Trypanosoma cruzi.

Infection with Trypanosoma cruzi causes expansion of subcutaneous (SLN) and atrophy of mesenteric (MLN) lymph nodes. Here we show that excision of MLN increased parasitemia in T. cruzi-infected mice. We then studied how apoptosis of MLN cells affects immune responses to infection. T cell apoptosis increased in the MLN compared to SLN in T. cruzi-infected mice. Absolute numbers of naïve T cells decreased, and activated T cells failed to accumulate in MLN during infection. In addition, activated T cells from MLN produced less IL-2, IFN-gamma, IL-4, and IL-10 than T cells from SLN. Treatment with IL-4 or with caspase-9 inhibitor increased the recovery of viable T cells in vitro. Treatment with caspase-9 inhibitor also increased the production of cytokines by MLN T cells from infected mice. Moreover, injection of a pan caspase inhibitor prevented MLN atrophy during T. cruzi infection. Caspase-9, but not caspase-8, inhibitor also reduced MLN atrophy and increased the recovery of naïve and activated T cells from MLN. These findings indicate that caspase-mediated apoptosis and defective cytokine production are implicated in MLN atrophy and affect immune responses to T. cruzi infection.

Resonances: from nuclear physics to mesoscopic systems / Resonancias: de la física nuclear a los isstemas mesoscópicos

ABSTRACT The properties of bound states and resonances in exotic nuclei and in mesoscopic system are discussed.

Se discutieron las propiedades de los estados enlazados y resonancias en núcleos exóticos y sistemas mesoscópicos.

The role of HFE mutations on iron metabolism in beta-thalassemia carriers.

Hereditary hemochromatosis (HH) is an autosomal recessive disorder of iron metabolism characterized by increased iron absorption and progressive storage resulting in organ damage. HFE gene mutations C282Y and H63D are responsible for the majority of HH cases. A third HFE mutation, S65C, has been associated with the development of a mild form of hemochromatosis. The beta-thalassemia trait is characterized by mild, ineffective erythropoiesis that can induce excess iron absorption and ultimately lead to iron overload. The aim of this study was to evaluate the effect of genetic markers (HFE mutations C282Y, H63D, and S65C) on the iron status of beta-thalassemia carriers. A total of 101 individuals heterozygous for beta-thalassemia and 101 normal control individuals were studied. The allelic frequencies of C282Y (1.5 versus 3.5%), H63D (15.3 versus 18.3%), and S65C (1.0 versus 1.5%) did not differ significantly between beta-thalassemia carriers and normal controls. Serum iron (P=0.029) and transferrin saturation (P=0.009) were increased in beta-thalassemia carriers heterozygous for H63D mutation. The number of subjects carrying C282Y or S65C mutations was too low to conclude their effect on the iron status. These results suggest that the beta-thalassemia trait tends to be aggravated with the coinheritance of H63D mutation, even when present in heterozygosity.

Active orthostatic stress and respiratory sinus arrhythmia in patients with Chagas' disease with preserved left ventricular global systolic function.

OBJECTIVE: To assess the use of the active orthostatic stress test for detecting vagal dysfunction in patients with Chagas' disease with preserved overall systolic function, and to compare it with the respiratory sinus arrhythmia test. METHODS: Sixty-one chagasic patients (Ch) and 38 nonchagasic (NCh) patients with no significant evidence of heart disease or systemic diseases underwent Doppler echocardiography and autonomic function tests. The respiratory sinus arrhythmia test was performed through electrocardiographic recording during deep breathing, at 6 ripm, calculating the E:I ratio (mean ratio between the longest expiratory RR interval and the shortest inspiratory RR interval at each cycle). The electrocardiogram was recorded during the act of standing and during the following 30 seconds (active orthostatic stress test), and the max RR/min RR ratio (the longest and shortest RR intervals right after change in posture) was calculated. The indices were adjusted for significant covariables. RESULTS: The max RR/min RR ratio (NCh: 1.52 [1.44-1.74] x Ch: 1.43 [1.33-1.51], P < 0.001) and the E:I ratio (NCh: 1.38 +/- 0.02 x Ch: 1.25 +/- 0.02, P<0.001) were lower among chagasic patients. A high correlation was observed between the adjusted max RR/min RR ratio and E:I ratio (r = 0.628, P < 0.001), but neither significantly correlated with left ventricular ejection fraction. CONCLUSION: Chagasic patients with preserved left ventricular overall systolic function showed a significant reduction in the vagal indices obtained on short-lasting tests, as compared with normal controls. The active orthostatic stress test that, showed a good correlation with the respiratory sinus arrhythmia maneuver, constituted a valid option for the outpatient care assessment of vagal control.

Active orthostatic stress and respiratory sinus arrhythmia in patients with Chagas' disease with preserved left ventricular global systolic function / Estresse ortostático ativo e arritmia sinusal respiratória em chagásicos com função sistólica global do ventrículo esquerdo preservada

OBJETIVO: Avaliar a utilização do teste de estresse ostostático ativo na detecção de disfunção vagal em chagásicos com função sistólica global preservada, comparando-o ao teste da arritmia sinusal respiratória. MÉTODO: Foram selecionados 61 chagásicos (Ch) e 38 não-chagásicos (NCh) sem evidências significativas de cardiopatia ou doenças sistêmicas, submetidos ao ecodopplercardiograma e às provas autonômicas. O teste da arritmia sinusal respiratória foi realizado através do registro eletrocardiográfico enquanto o paciente respirava profundamente, a 6 irpm, calculando-se a razão E:I (média das razões entre os maiores intervalos RR expiratórios e os menores RR inspiratórios a cada ciclo). O eletrocardiograma foi registrado enquanto o paciente se levantava e nos 30s seguintes (teste do estresse ortostático ativo), calculando-se a razão RR máx./RR min (maior e menor intervalo RR logo após a mudança postural). Os índices foram ajustados para covariáveis significativas. RESULTADOS: A razão RR max:min (NCh: 1,52 [1,44-1,74] x Ch: 1,43 [1,33-1,51], p < 0,001) e a razão E:I (NCh: 1,38±0,02 x Ch: 1,25±0,02, p<0,001) foram menores entre os chagásicos. Houve elevada correlação entre a razão RR max:min e a razão E:I ajustadas (r = 0,628, p < 0,001), mas ambas não se correlacionaram significativamente com a fração de ejeção do ventrículo esquerdo. CONCLUSAO: Chagásicos com função sistólica global do ventrículo esquerdo preservada apresentam redução significativa de índices vagais obtidos por provas curtas, quando comparados a controles normais. O teste de estresse ortostático ativo apresentou boa correlação com a manobra de arritmia sinusal respiratória, constituindo-se opção válida na avaliação ambulatorial do controle vagal.