Influences of temporal independence of data on modelling species distributions

Modelling species distributions has been widely used to understand present and future potential distributions of species, and can provide adaptation and mitigation information as references for conservation and management under climate change. However, various methods of data splitting to develop and validate functions of the models do not get enough attention, which may mislead the interpretation of predicted results. We used the Taiwanese endemic birds to test the influences of temporal independence of datasets on model performance and prediction. Training and testing data were considered to be independent if they were collected during different survey periods (1993–2004 and 2009–2010). The results indicated no significant differences of six model performance measures (AUC, kappa, TSS, accuracy, sensitivity, and specificity) among the combinations of training and testing datasets. Both species- and grid cell-based assessments differed significantly between predictions by the annual and pooled training data. We also found an average of 85.8% similarity for species presences and absences in different survey periods. The remaining dissimilarity was mostly caused by species observed in the late survey period but not in the early one. The method of data splitting, yielding training and testing data, is critical for resulting model species distributions. Even if similar model performance exists, different methods can lead to different species distributional maps. More attention needs to be given to this issue, especially when amplifying these models to project species distributions in a changing world.     

Drosophila DBT Autophosphorylation of Its C-Terminal Domain Antagonized by SPAG and Involved in UV-Induced Apoptosis

Drosophila DBT and vertebrate CKIε/δ phosphorylate the period protein (PER) to produce circadian rhythms. While the C termini of these orthologs are not conserved in amino acid sequence, they inhibit activity and become autophosphorylated in the fly and vertebrate kinases. Here, sites of C-terminal autophosphorylation were identified by mass spectrometry and analysis of DBT truncations. Mutation of 6 serines and threonines in the C terminus (DBT^C/ala) prevented autophosphorylation-dependent DBT turnover and electrophoretic mobility shifts in S2 cells. Unlike the effect of autophosphorylation on CKIδ, DBT autophosphorylation in S2 cells did not reduce its in vitro activity. Moreover, overexpression of DBT^C/ala did not affect circadian behavior differently from wild-type DBT (DBT^WT), and neither exhibited daily electrophoretic mobility shifts, suggesting that DBT autophosphorylation is not required for clock function. While DBT^WT protected S2 cells and larvae from UV-induced apoptosis and was phosphorylated and degraded by the proteasome, DBT^C/ala did not protect and was not degraded. Finally, we show that the HSP-90 cochaperone spaghetti protein (SPAG) antagonizes DBT autophosphorylation in S2 cells. These results suggest that DBT autophosphorylation regulates cell death and suggest a potential mechanism by which the circadian clock might affect apoptosis.     

Effect of adenovirus and influenza virus infection on obesity

The purpose of this review is to provide an overview of the effects of adenovirus and influenza virus infections on obesity in various experimental models. We reviewed studies that were conducted within the past 10 years and were related to virus infection and obesity prevalence. Here, we discuss a different causal relationship between adenovirus and influenza infections with obesity. Adenovirus infection can cause obesity, whereas obesity can be a risk factor for increasing influenza virus infection and increases the risk of morbidity and mortality. The prevalence of obesity due to adenovirus infections may be due to an increase in glucose uptake and reduction in lipolysis caused by an increase in corticosterone secretion. Adenovirus infections may lead to increases in appetite by decreasing norepinephrine and leptin levels and also cause immune dysfunction. The relationship between obesity and influenza virus infection could be summarized by the following features: decreases in memory T-cell functionality and interferon (IFN)-α, IFN-β, and IFN-γ mRNA expression, increases in viral titer and infiltration, and impaired dendritic cell function in obese individuals. Moreover, leptin resistance may play an important role in increasing influenza virus infections in obese individuals. In conclusion, prevention of adenovirus infections could be a good approach for reducing obesity prevalence, and prevention of obesity could reduce influenza virus infections from the point of view of viral infections and obesity.     

The 24-h time budget of a takh harem stallion (Equus ferus przewalskii) pre- and post-reintroduction

Focal animal sampling was used to determine the 24-h time budget of a takh harem stallion (Equus ferus przewalskii) during the 2 weeks prior to, and the two weeks following, reintroduction into the Hustain Nuruu Steppe Reserve, Mongolia. Both before and after release, the stallion spent approximately 47% of his time grazing, 6% standing, and 5% in recumbent rest. The biggest changes to the time budget after release were a 4-fold increase in the amount of time spent moving, and a 50% decrease in the amount of time spent resting in a standing position. During the middle of the day when the temperatures were hottest, the stallion exhibited less grazing and more standing resting behaviour than in the morning or evening hours. Recumbent rest invariably occurred in the hours before dawn.