New records for Guyana, with description of the voice of Roraiman Nightjar Caprimulgus whitelyi

Volume: 127Start Page: 118End Page: 12

Degradation Phenomena of Bismuth-Modified Felt Electrodes in VRFB Studied by Electrochemical Impedance Spectroscopy

The performance of all-V redox flow batteries (VRFB) will decrease when they are exposed to dynamic electrochemical cycling, but also when they are in prolonged contact with the acidic electrolyte. These phenomena are especially severe at the negative side, where the parasitic hydrogen evolution reaction (HER) will be increasingly favored over the reduction of V(III) with ongoing degradation of the carbon felt electrode. Bismuth, either added to the electrolyte or deposited onto the felt, has been reported to suppress the HER and therefore to enhance the kinetics of the V(II)/V(III) redox reaction. This study is the first to investigate degradation effects on bismuth-modified electrodes in the negative half-cell of a VRFB. By means of a simple impregnation method, a commercially available carbon felt was decorated with Bi 2 O 3 , which is supposedly present as Bi(0) under the working conditions at the negative side. Modified and unmodified felts were characterized electrochemically using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) in a three-electrode setup. Surface morphology of the electrodes and composition of the negative half-cell electrolyte were probed using scanning electron microscopy (SEM) and X-ray fluorescence spectroscopy (TXRF), respectively. This was done before and after the electrodes were subjected to 50 charge-discharge cycles in a battery test bench. Our results suggest that not only the bismuth catalyst is dissolved from the electrode during battery operation, but also that the presence of bismuth in the system has a strong accelerating effect on electrode degradation

Avian Hematozoa in South America: a Comparison of Temperate and Tropical Zones

We used screening techniques based on polymerase chain reaction (PCR) to explore the avian hematozoan parasites (Plasmodium spp. and Haemoproteus spp.) of two previously uninvestigated regions of continental South America. Comparisons of tropical-zone Guyana and temperate-zone Uruguay revealed that overall prevalence of Plasmodium and Haemoproteus species detected in a diverse sampling of potential hosts was significantly higher in Guyana. The difference in prevalence between the two geographic zones appears to be attributable to ecological differences rather than taxonomic sampling artifacts. Diversity of hematozoan haplotypes was also higher in Guyana. We found no relationship between hematozoan haplotype and host family sampled within or between regions. We found very few Plasmodium and no Haemoproteus haplotypes shared between the two regions, and evidence of geographic structuring of hematozoan haplotypes between the two regions. We suggest that a lack of hematozoan haplotype transmission between the two regions may be attributable to the migratory patterns of each region\u27s avian hosts

Gender differences of patients at-risk for psychosis regarding symptomatology, drug use, comorbidity and functioning - Results from the EU-GEI study

Background: Gender differences in symptomatology in chronic schizophrenia and first episode psychosis patients have often been reported. However, little is known about gender differences in those at risk of psychotic disorders. This study investigated gender differences in symptomatology, drug use, comorbidity (i.e. substance use, affective and anxiety disorders) and global functioning in patients with an at-risk mental state (ARMS) for psychosis. Methods: The sample consisted of 336 ARMS patients (159 women) from the prodromal work package of the EUropean network of national schizophrenia networks studying Gene-Environment Interactions (EU-GEI; 11 centers). Clinical symptoms, drug use, comorbidity and functioning were assessed at first presentation to an early detection center using structured interviews. Results: In unadjusted analyses, men were found to have significantly higher rates of negative symptoms and current cannabis use while women showed higher rates of general psychopathology and more often displayed comorbid affective and anxiety disorders. No gender differences were found for global functioning. The results generally did not change when corrected for possible cofounders (e.g. cannabis use). However, most differences did not withstand correction for multiple testing. Conclusions: Findings indicate that gender differences in symptomatology and comorbidity in ARMS are similar to those seen in overt psychosis and in healthy controls. However, observed differences are small and would only be reliably detected in studies with high statistical power. Moreover, such small effects would likely not be clinically meaningful. (C) 2019 Published by Elsevier Masson SAS

Gender differences of patients at-risk for psychosis regarding symptomatology, drug use, comorbidity and functioning - Results from the EU-GEI study

Background Gender differences in symptomatology in chronic schizophrenia and first episode psychosis patients have often been reported. However, little is known about gender differences in those at risk of psychotic disorders. This study investigated gender differences in symptomatology, drug use, comorbidity (i.e. substance use, affective and anxiety disorders) and global functioning in patients with an at-risk mental state (ARMS) for psychosis. Methods The sample consisted of 336 ARMS patients (159 women) from the prodromal work package of the EUropean network of national schizophrenia networks studying Gene-Environment Interactions (EU-GEI; 11 centers). Clinical symptoms, drug use, comorbidity and functioning were assessed at first presentation to an early detection center using structured interviews. Results In unadjusted analyses, men were found to have significantly higher rates of negative symptoms and current cannabis use while women showed higher rates of general psychopathology and more often displayed comorbid affective and anxiety disorders. No gender differences were found for global functioning. The results generally did not change when corrected for possible cofounders (e.g. cannabis use). However, most differences did not withstand correction for multiple testing. Conclusions Findings indicate that gender differences in symptomatology and comorbidity in ARMS are similar to those seen in overt psychosis and in healthy controls. However, observed differences are small and would only be reliably detected in studies with high statistical power. Moreover, such small effects would likely not be clinically meaningful