Developing a predictive modelling capacity for a climate change-vulnerable blanket bog habitat: Assessing 1961-1990 baseline relationships

Aim: Understanding the spatial distribution of high priority habitats and developing predictive models using climate and environmental variables to replicate these distributions are desirable conservation goals. The aim of this study was to model and elucidate the contributions of climate and topography to the distribution of a priority blanket bog habitat in Ireland, and to examine how this might inform the development of a climate change predictive capacity for peat-lands in Ireland. Methods: Ten climatic and two topographic variables were recorded for grid cells with a spatial resolution of 1010 km, covering 87% of the mainland land surface of Ireland. Presence-absence data were matched to these variables and generalised linear models (GLMs) fitted to identify the main climatic and terrain predictor variables for occurrence of the habitat. Candidate predictor variables were screened for collinearity, and the accuracy of the final fitted GLM was evaluated using fourfold cross-validation based on the area under the curve (AUC) derived from a receiver operating characteristic (ROC) plot. The GLM predicted habitat occurrence probability maps were mapped against the actual distributions using GIS techniques. Results: Despite the apparent parsimony of the initial GLM using only climatic variables, further testing indicated collinearity among temperature and precipitation variables for example. Subsequent elimination of the collinear variables and inclusion of elevation data produced an excellent performance based on the AUC scores of the final GLM. Mean annual temperature and total mean annual precipitation in combination with elevation range were the most powerful explanatory variable group among those explored for the presence of blanket bog habitat. Main conclusions: The results confirm that this habitat distribution in general can be modelled well using the non-collinear climatic and terrain variables tested at the grid resolution used. Mapping the GLM-predicted distribution to the observed distribution produced useful results in replicating the projected occurrence of the habitat distribution over an extensive area. The methods developed will usefully inform future climate change predictive modelling for Irelan

Rigorous derivation of the Kuramoto-Sivashinsky equation from a 2D weakly nonlinear Stefan problem

We are interested in a rigorous derivation of the Kuramoto-Sivashinsky (K-S) equation from a free boundary problem. As a paradigm, we consider a two-dimensional Stefan problem in a strip, a simplified version of a solid-liquid interface model. Near the instability threshold, we introduce a small parameter e and define rescaled variables accordingly. At fixed ε, our method is based on: definition of a suitable linear 1D operator, projection with respect to the longitudinal coordinate only, and the Lyapunov-Schmidt method. As a solvability condition, we derive a self-consistent parabolic equation for the front. We prove that, starting from the same configuration, the latter remains close to the solution of K-S on a fixed time interval, uniformly in ε\ sufficiently small. © European Mathematical Society 2011

Desempenho reprodutivo pós-parto de vacas de corte submetidas a indução/sincronização de cio Postpartum reproductive performance of beef cows in moderate body condition submitted to estrus induction/synchronization

Para avaliar o desempenho reprodutivo de vacas de corte submetidas à indução/sincronização de cio, foram utilizadas 42 vacas da raça Aberdeen Angus com condição corporal 3 (escala de 1-5) sob manejo extensivo. A produção de leite foi estimada pelo método pesagem-mamada-pesagem. Nos exames ginecológicos, utilizou-se aparelho de ultra-sonografia e palpação trans-retal. Foram considerados fatores fixos nível de produção de leite (acima e abaixo da média de produção das vacas), gestação, condição reprodutiva pré-acasalamento (CRPA), anestro superficial (tônus uterino, folículos > 10 mm e ausência de CL) e anestro profundo (ausência de tônus uterino, folículos < 10 mm e ausência de CL) e a resposta à indução/sincronização de cio (RISC). As variáveis analisadas foram os pesos pré-parto, ao parto, ao acasalamento e à concepção, o peso à desmama, o ganho médio de peso diário do parto ao desmame e a produção de leite total. A condição reprodutiva pré-acasalamento foi influenciada pelos pesos pré-parto e ao parto, comprovando que o melhor desempenho pré-parto e ao parto favorece o restabelecimento da atividade reprodutiva em vacas com condição corporal (CC) moderada no período pós-parto. A classificação da condição reprodutiva pré-acasalamento em vacas de corte pode ser um recurso para determinar o desempenho reprodutivo de vacas de corte submetidas à indução/sincronização de cio, uma vez que vacas em anestro superficial tendem a apresentar melhor resposta ao protocolo. Em vacas de corte com condição corporal moderada, o desempenho ponderal pré-parto influencia a condição reprodutiva pré-acasalamento, aumentando a probabilidade de melhor desempenho reprodutivo.<br>To assess the reproductive performance of beef cows submitted to estrus induction/synchronization, 42 Aberdeen Angus cows with body condition 3 (1-5 scale) under extensive management were used. The milk production was estimated through the weight-suckling-weight method. For gynecological examinations, ultrasound equipment and trans-rectal palpation were used. The milk production level (above and below the average production of cows), pregnancy, prebreeding reproductive condition (CRPA), surface anoestrus (uterine tone, follicles > 10 mm and absence of CL) and deep anoestrus (no uterine tone, follicles <10 mm and absence of CL) and the estrus induction/synchronization response (RISC) were considered as constant factors. The variables analyzed were the pre-delivery, delivery weight, mating and conception weights, weaning weight, the average daily weight gain from birth to weaning and total milk production. The prebreeding reproductive condition influenced the pre-birth and birth weights, showing that the better pre-birth and birth performance favors the restoration of reproductive activity in cows with moderate body condition (CC) in the post-partum period. The classification of the pre-breeding reproductive condition in beef cows can be a resource to determine the reproductive performance of beef cows submitted to estrus induction/synchronization, since cows in surface anoestrus tend to have better response to the protocol. In beef cows with moderate body condition, the pre-birth weight performance affects the prebreeding reproductive condition, increasing the likelihood of better reproductive performance

Density and behavior of capybara (Hydrochoerus hydrochaeris) ticks (Acari: Ixodidae) Amblyomma sculptum and Amblyomma dubitatum with notes on Rickettsia bellii infection: Assessing human exposure risk

In several urban and peri‑urban areas of Brazil, populations of Amblyomma sculptum and Amblyomma dubitatum ticks are maintained by capybaras (Hydrochoerus hydrochaeris). In some of these areas, this host and these tick species are associated with Brazilian spotted fever (BSF), a lethal human disease caused by the bacterium Rickettsia rickettsii. In this work, we evaluated the risk of human exposure to these tick species using four collection techniques to discern host-seeking behavior. The study was carried out in 10 urban sites inhabited by capybaras in Uberlândia, a BSF-free municipality in southeastern Brazil. Ticks were collected in areas of 400 m2 at each site and at three seasons. Within the same municipality, the distance and speed of A. sculptum nymphs moving towards the CO2 traps were evaluated. In a sample of ticks Rickettsia DNA was investigated. During the study period, 52,953 ticks were collected. Among these, 83.4 % were A. sculptum (1,523 adults, 10,545 nymphs and 32,104 larvae) and 16.6 % were A. dubitatum (464 adults, 2,153 nymphs and 6,164 larvae). An average annual questing tick density of 4.4/m² was observed, with the highest density recorded at one site in autumn (31.8/m²) and the lowest in summer at another site (0.03/m²). The visual search yielded the highest proportion of A. sculptum larvae, constituting 47 % of the total and 63.6 % of all A. sculptum larvae. In contrast, CO2 traps collected a greater proportion of nymphs and adults of A. sculptum ticks. In the case of A. dubitatum, the CO2 trap was the most efficient technique with 57.7 % of captures of this species, especially of nymphs (94.5 % of captures) and adults (97.8 % of captures). Ticks' ambush height on vegetation (9 to 77 cm), observed by visual search 30 times, yielded a total of 20,771 ticks. Of these, 28 (93 %) were A. sculptum ticks, with only two (7 %) identified as A. dubitatum ticks. Among A. sculptum ticks, the nymph was the most attracted stage to humans and larva in the case of A. dubitatum. Amblyomma sculptum adults and nymphs were significantly more attracted to humans than those of A. dubitatum, but A. dubitatum larvae were significantly more attracted than the same stage of A. sculptum. The maximum distance and speed of horizontal displacement for A. sculptum nymphs were five meters and 2.0 m/h, respectively. The only species of Rickettsia detected in ticks, exclusively in A. dubitatum, was R. bellii. Importantly, it was observed that the higher the proportion of A. sculptum in the community of ticks, the lower the rate of infection of A. dubitatum by R. bellii. In conclusion, host-seeking behavior differed between the two tick species, as well as between stages of the same species. A greater restriction of A. dubitatum ticks to the soil was observed, while larvae and nymphs of A. sculptum dispersed higher in the vegetation. The behavior presented by A. sculptum provides greater opportunities for contact with the hosts, while A. dubitatum depends more on an active search for a host, the hunter behavior. Taken together, these observations show that a human being crossing an area infested with A. sculptum and A. dubitatum ticks will have almost exclusive contact with A. sculptum larvae and/or nymphs. Humans in a stationary position (sitting, lying or immobile) are exposed to both tick species, but they are more attractive to adults and mainly nymphs of A. sculptum compared to the corresponding stages of the tick A. dubitatum. The negative effect of A. sculptum on A. dubitatum infection by R. bellii deserves further studies