Spatial patterns of Qualea grandiflora in cerrado fragments in Sao Paulo state

(Spatial patterns of Qualea grandiflora in cerrado fragments in Sao Paulo state). The study of spatial patterns is a helpful approach to formulating hypotheses about plant population dynamics. Our aim was to search for variation in spatial patterns of Q. grandiflora height classes at different scales within and among fragments of different cerrado physiognomies. Spatial patterns of the number of plants in subplots (5 x 5 m) were described and compared among six 0.5-ha plots placed in four fragments. We performed Moran's I correlogram analysis to describe spatial patterns and tested spatial correlations of height classes by partial Mantel tests. We found 18 to 319 plants 0.5 ha(-1). Larger plants (height >1.5 m) had a clumped pattern in all plots, varying in numbers and magnitudes of scales independently of the physiognomy. Correlogram analysis for smaller plants was possible in only three plots, where patterns were random. In two of these cases there was significant positive correlation of size classes but in the third it was not significant. Abundance and spatial patterns were as different within the same fragment as in different ones. These results show that Q. grandiflora spatial patterns cannot be predicted based on overall characteristics of cerrado physiognomy. The random-to-clumped transition with size and the spatial association of classes suggest that density dependent mortality does not seem to be an important driver of Q. grandiflora dynamics, and that spatial structure of suitable sites for recruitment to maturity may be more important.25121522

24-Week β-alanine ingestion does not affect muscle taurine or clinical blood parameters in healthy males

Purpose: To investigate the effects of chronic beta-alanine (BA) supplementation on muscle taurine content, blood clinical markers and sensory side-effects. Methods: Twenty-five healthy male participants (age 27±4 years, height 1.75±0.09 m, body mass 78.9±11.7 kg) were supplemented with 6.4 g day−1 of sustained-release BA (N=16; CarnoSyn™, NAI, USA) or placebo (PL; N=9; maltodextrin) for 24 weeks. Resting muscle biopsies of the m. vastus lateralis were taken at 0, 12 and 24 weeks and analysed for taurine content (BA, N=12; PL, N=6) using high-performance liquid chromatography. Resting venous blood samples were taken every 4 weeks and analysed for markers of renal, hepatic and muscle function (BA, N=15; PL, N=8; aspartate transaminase; alanine aminotransferase; alkaline phosphatase; lactate dehydrogenase; albumin; globulin; creatinine; estimated glomerular filtration rate and creatine kinase). Results :There was a significant main effect of group (p=0.04) on muscle taurine, with overall lower values in PL, although there was no main effect of time or interaction effect (both p>0.05) and no differences between specific timepoints (week 0, BA: 33.67±8.18 mmol kg−1 dm, PL: 27.75±4.86 mmol kg−1 dm; week 12, BA: 35.93±8.79 mmol kg−1 dm, PL: 27.67±4.75 mmol kg−1 dm; week 24, BA: 35.42±6.16 mmol kg−1 dm, PL: 31.99±5.60 mmol kg−1 dm). There was no effect of treatment, time or any interaction effects on any blood marker (all p>0.05) and no self-reported side-effects in these participants throughout the study. Conclusions: The current study showed that 24 weeks of BA supplementation at 6.4 g day−1 did not significantly affect muscle taurine content, clinical markers of renal, hepatic and muscle function, nor did it result in chronic sensory side-effects, in healthy individuals. Since athletes are likely to engage in chronic supplementation, these data provide important evidence to suggest that supplementation with BA at these doses for up to 24 weeks is safe for healthy individuals

Does the road to happiness depend on the retirement decision? Evidence from Italy

This study estimates the causal effect of retirement decision on well-being in Italy. To do so, the authors exploit the exogenous variation provided by the changes in the eligibility criteria for pensions that were enacted in Italy in 1995 (Dini’s law) and in 1997 (Prodi’s law, from the names of the prime ministers at the time of their introduction). A sizeable and positive impact of retirement decision is found on satisfaction with leisure time and on frequency of meeting friends. Furthermore, the results are generalized, allowing for the estimation of different moments from different data sources

Heterogeneities in leishmania infantum infection : using skin parasite burdens to identify highly infectious dogs

Background: The relationships between heterogeneities in host infection and infectiousness (transmission to arthropod vectors) can provide important insights for disease management. Here, we quantify heterogeneities in Leishmania infantum parasite numbers in reservoir and non-reservoir host populations, and relate this to their infectiousness during natural infection. Tissue parasite number was evaluated as a potential surrogate marker of host transmission potential. Methods: Parasite numbers were measured by qPCR in bone marrow and ear skin biopsies of 82 dogs and 34 crab-eating foxes collected during a longitudinal study in Amazon Brazil, for which previous data was available on infectiousness (by xenodiagnosis) and severity of infection. Results: Parasite numbers were highly aggregated both between samples and between individuals. In dogs, total parasite abundance and relative numbers in ear skin compared to bone marrow increased with the duration and severity of infection. Infectiousness to the sandfly vector was associated with high parasite numbers; parasite number in skin was the best predictor of being infectious. Crab-eating foxes, which typically present asymptomatic infection and are non-infectious, had parasite numbers comparable to those of non-infectious dogs. Conclusions: Skin parasite number provides an indirect marker of infectiousness, and could allow targeted control particularly of highly infectious dogs

The effect of intervertebral cartilage on neutral posture and range of motion in the necks of sauropod dinosaurs

The necks of sauropod dinosaurs were a key factor in their evolution. The habitual posture and range of motion of these necks has been controversial, and computer-aided studies have argued for an obligatory sub-horizontal pose. However, such studies are compromised by their failure to take into account the important role of intervertebral cartilage. This cartilage takes very different forms in different animals. Mammals and crocodilians have intervertebral discs, while birds have synovial joints in their necks. The form and thickness of cartilage varies significantly even among closely related taxa. We cannot yet tell whether the neck joints of sauropods more closely resembled those of birds or mammals. Inspection of CT scans showed cartilage:bone ratios of 4.5% for Sauroposeidon and about 20% and 15% for two juvenile Apatosaurus individuals. In extant animals, this ratio varied from 2.59% for the rhea to 24% for a juvenile giraffe. It is not yet possible to disentangle ontogenetic and taxonomic signals, but mammal cartilage is generally three times as thick as that of birds. Our most detailed work, on a turkey, yielded a cartilage:bone ratio of 4.56%. Articular cartilage also added 11% to the length of the turkey's zygapophyseal facets. Simple image manipulation suggests that incorporating 4.56% of neck cartilage into an intervertebral joint of a turkey raises neutral posture by 15°. If this were also true of sauropods, the true neutral pose of the neck would be much higher than has been depicted. An additional 11% of zygapophyseal facet length translates to 11% more range of motion at each joint. More precise quantitative results must await detailed modelling. In summary, including cartilage in our models of sauropod necks shows that they were longer, more elevated and more flexible than previously recognised

Gravitational collapse and thermalization in the hard wall model

We study a simple example of holographic thermalization in a confining field theory: the homogeneous injection of energy in the hard wall model. Working in an amplitude expansion, we find black brane formation for sufficiently fast energy injection and a scattering wave solution for sufficiently slow injection. We comment on our expectations for more sophisticated holographic QCD models.Comment: 33 pages, 5 figure