Potential impacts of climate change on distribution range of Nabis pseudoferus and N. palifer (Hemiptera: Nabidae) in Iran

Nabis pseudoferus Remane and N. palifer Seidenstucker are predators that feed on a wide range of insect pests. To reveal their current potential habitats, the effects of climate change and their future distribution in various areas of Iran we used maximum entropy modeling (Maxent). To produce the models, samples were collected from 218 areas of Iran resulting in discovering 271 points where the nabids were found. The accuracy and performance of distribution models were also evaluated by the area under receiver operating characteristic curve and jack‐knife analysis. In the Maxent model, the climatic, elevation and land cover layers were the major bases for the current models. In modeling future distribution, the land cover layer was excluded. The distribution of N. pseudoferus was independent of the type of vegetation while the distribution of N. palifer varied according to differences in type of vegetation. Using jack‐knife analysis, the land cover and precipitation were the most effective predictors driving the two Nabis species range expansion. From 2013 to 2050 the impacts of climate change on N. pseudoferus distribution was predicted to have a negative impact but have a positive effect on N. palifer range expansion. Results could be used in preparation of predators' conservation, translocation and reintroduction programs and application in pest management strategies.     

Comparison of dynamic responses of cellular metabolites in <Emphasis Type="Italic">Escherichia coli</Emphasis> to pulse addition of substrates

We conducted an integrated study of cell growth parameters, product formation, and the dynamics of intracellular metabolite concentrations using Escherichia coli with genes knocked out in the glycolytic and oxidative pentose phosphate pathway (PPP) for glucose catabolism. We investigated the same characteristics in the wild-type strain, using acetate or pyruvate as the sole carbon source. Dramatic effects on growth parameters and extracellular and intracellular metabolite concentrations were observed after blocking either glycolytic breakdown of glucose by inactivation of phosphoglucose isomerase (disruption of pgi gene) or pentose phosphate breakdown of glucose by inactivation of glucose-6-phosphate dehydrogenase (disruption of zwf gene). Reducing power (NADPH) was mainly produced through PPP when the pgi gene was knocked out, while NADPH was produced through the tricarboxylic acid (TCA) cycle by isocitrate dehydrogenase or NADP-linked malic enzyme when the zwf gene was knocked out. As expected, when the pgi gene was knocked out, intracellular concentrations of PPP metabolites were high and glycolytic and concentrations of TCA cycle pathway metabolites were low. In the zwf gene knockout, concentrations of PPP metabolites were low and concentrations of intracellular glycolytic and TCA cycle metabolites were high.     

Higher plasma levels of F2-isoprostanes are associated with slower psychomotor speed in healthy older adults

Oxidative stress has been identified as a process which is detrimental to brain health, and associated with age-related cognitive declines. Few studies to-date have examined the relationship between in vivo oxidative stress biomarkers and cognitive performance within healthy elderly populations. The current study investigated the relationship between reaction time and oxidative stress, as measured by blood plasma concentrations of F₂-isoprostanes using a sample of 251 healthy, non-demented, elderly volunteers (Male; 111: Female 140) aged 60–75 years from the Australian Research Council Longevity Intervention (ARCLI) study cohort. A Jensen Box was used in conjunction with the Hick paradigm in order to differentiate simple from choice reaction time (two, four and eight-choice conditions) as well as movement (MT) and decision times (DT). MT, but not DT, was found to be significantly slower for participants in the high F₂-isoprostane group compared to the low F₂-isoprostane group, across all stimulus choices. F₂-isoprostanes, age and Wechsler Abbreviated Scale of Intelligence (WASI) full scale intelligence quotient (IQ) were found to be significant predictors of average MT in the sample as a whole. These findings provide preliminary evidence to suggest that higher levels of oxidative stress may be associated with impaired psychomotor speed in the healthy elderly population.