Altered ATP Hydrolysis Induced by Pentylenetetrazol Kindling in Rat Brain Synaptosomes

The ectonucleotidase pathway is an important metabolic source of extracellular adenosine. Adenosine has potent anticonvulsant effects on various models of epilepsy. One of these models is pentylenetetrazol (PTZ) kindling, in which repeated administration of subconvulsive doses of this drug induces progressive intensification of seizure activity. In this study, we examine the effect of a single convulsive injection (60 mg/kg, i.p.) or 10 successive (35 mg/kg, i.p.) injections of PTZ on synaptosomal ectonucleotidases. Our results have shown that no changes in ectonucleotidase activities were seen at 0, 1, and 24 h or at 5 days after a single convulsive PTZ injection. However, after PTZ-kindling, rats which were more resistant to seizure development presented an increase in ATP hydrolysis in synaptosomes from hippocampus and cerebral cortex (44% and 28%, respectively). These results suggest that changes in nucleotide hydrolysis may represent an important mechanism in the modulation of chronic epileptic activity in this model.     

The Possible Role of Resource Requirements and Academic Career-Choice Risk on Gender Differences in Publication Rate and Impact

Many studies demonstrate that there is still a significant gender bias, especially at higher career levels, in many areas including science, technology, engineering, and mathematics (STEM). We investigated field-dependent, gender-specific effects of the selective pressures individuals experience as they pursue a career in academia within seven STEM disciplines. We built a unique database that comprises 437,787 publications authored by 4,292 faculty members at top United States research universities. Our analyses reveal that gender differences in publication rate and impact are discipline-specific. Our results also support two hypotheses. First, the widely-reported lower publication rates of female faculty are correlated with the amount of research resources typically needed in the discipline considered, and thus may be explained by the lower level of institutional support historically received by females. Second, in disciplines where pursuing an academic position incurs greater career risk, female faculty tend to have a greater fraction of higher impact publications than males. Our findings have significant, field-specific, policy implications for achieving diversity at the faculty level within the STEM disciplines.     

Listericidal activity of human neutrophil cathepsin G

We demonstrate that cathepsin G, derived from human neutrophils, exhibits potent in vitro antimicrobial activity against Listeria monocytogenes. Cathepsin G listericidal activity was by a non-enzymic mechanism and was dependent on the cationic nature of the molecule. The listericidal activity of cathepsin G occurred in a manner that was both time-dependent and concentration-dependent.     

Historical Biogeography of Delphininae Dolphins and Related Taxa (Artiodactyla: Delphinidae)

Delphinine dolphins arose via a recent, rapid radiation, probably within the last four million years. Although molecular phylogenies are increasingly well resolved, patterns of morphology-ecology-geography are hard to link to phylogeny or to translate into taxonomy. Such problems might be tackled through understanding the drivers of the delphinine radiation. Here, we examine delphinine historical biogeography using the phylogeny of McGowen et al. (Mol Phylogenet Evol 53:891–906, 2009) as our working hypothesis. We used the “Spatial Analysis of Vicariance” method to delimit modern distribution patterns, including disjunctions involving sister nodes in the Delphininae. The analysis identified disjunct sister nodes, allowing some interpretation of Delphininae biogeography. The Central American Seaway was probably an important gateway for early delphinids, but the succeeding “hard” barrier of the Panama Isthmus had little influence. Southern African waters form the Atlantic-Indo-Pacific gateway, which is sometimes considered a “soft” barrier because of the variation in the Benguela and Agulhas currents, in turn driven by tectonic changes and/or Pleistocene glacial and interglacial cycles. The latter cycles probably fragmented coastal habitats, allowing allopatric speciation. Geological patterns of turnover in Southern Ocean diatoms, which link to physical oceanic change, closely match the main cluster of delphinine divergences. The Eastern Pacific Barrier, and perhaps the associated Humboldt Current and equatorial “cold tongue,” affect modern distributions, but cause and effect are poorly understood. Future research should involve molecular-morphological phylogenetics for all species, subspecies, and ecomorphs. Complete distributions must be known for all taxa to understand how vicariance and dispersal shaped the distribution of delphinines.     

Evaluating the carbon footprint of the cork sector with a dynamic approach including biogenic carbon flows

Purpose

The aim of the present study is to assess the influence of two different attributional life cycle assessment (LCA) approaches, namely static LCA (sLCA) and dynamic LCA (dLCA), through their application to the calculation of the carbon footprint (CF) of the entire cork sector in Portugal. The effect of including biogenic carbon sequestration and emissions is considered as well.

Methods

sLCA is often described as a static tool since all the emissions are accounted for as if occurring at the same time which may not be the case in reality for greenhouse gases. In contrast, dLCA aims to evaluate the impact of life cycle greenhouse gas emissions on radiative forcing considering the specific moment when these emissions occur.

Results and discussion

The results show that the total CF of the cork sector differs depending on the approach and time horizon chosen. However, the greater it is the time horizon chosen, the smaller the difference between the CF results of the two approaches. Additionally, the inclusion of biogenic carbon sequestration and emissions also influences significantly the CF result. The cork sector is considered a net carbon source when biogenic carbon is excluded from the calculations and a net carbon sink when biogenic carbon is included in the calculations since more carbon is sequestered than emitted along the sector.

Conclusions

dLCA allows an overview of greenhouse gas emissions along the time. This is an advantage as it allows to identify and plan different management approaches for the cork sector. Even though dLCA is a more realistic approach, it is a more time-consuming and complex approach for long life cycles. The choice of time horizon was found to be another important aspect for CF assessment.