1,347 research outputs found
Colour variation of the Maltese wall lizards (Podarcis filfolensis) at population and individual levels in the Linosa island
AbstractThe research on animal colouration has always been of great interest for biologists but since the last decades it has grown exponentially thanks to multidisciplinary approaches. Animals have found several ways to deal with the camouflage/communication trade-off in colouration, leading to the evolution of alternative patterns of variation of colourations at different levels including signal partitioning and spatial resolution of colouration. In this paper we analyse the variability of dorsal and ventral colouration in males and females of Maltese wall lizards in three populations on Linosa. We collected high-resolution digital images of dorsal, ventral and throat colouration from 61 lizards (32 males and 29 females). We showed that the colouration differs among sexes and body regions within the same individual. Colourations are also variable among individuals within population, as well as among different populations across the Island. Finally, we detected a lizard's colouration shifts with increasing body size. Those result supports the hypothesis that colouration in this species evolved under the competing pressures of natural and sexual selection to promote signals that are visible to conspecifics while being less perceptible to avian predators.
Graphic abstrac
Can fiscal decentralization alleviate government consumption volatility?
We analyse how fiscal decentralization affects the volatility of government consumption extending the existing literature that mainly deals with the effects of the former on government size. Using data for 97 developed and developing countries from 1971 to 2010, we find that a higher degree of fiscal decentralization leads to lower government consumption volatility. This result holds for the sub-sample of advanced economies, while it is not confirmed for those less-developed. This mechanism seems to work mainly through a lower volatility of the non-discretionary spending, which typically belongs to the central government’s policy. We also confirm existing findings according to which country size lowers government spending volatility. Thus, given a minimum level of development, fiscal decentralization reforms can reduce spending volatility by distributing power to sub-central governments, particularly in smaller countries which are usually more prone to volatility
Can fiscal decentralization alleviate government consumption volatility?
We analyse how fiscal decentralization affects the volatility of government consumption extending the existing literature that mainly deals with the effects of the former on government size. Using data for 97 developed and developing countries from 1971 to 2010, we find that a higher degree of fiscal decentralization leads to lower government consumption volatility. This result holds for the sub-sample of advanced economies, while it is not confirmed for those less-developed. This mechanism seems to work mainly through a lower volatility of the non-discretionary spending, which typically belongs to the central government’s policy. We also confirm existing findings according to which country size lowers government spending volatility. Thus, given a minimum level of development, fiscal decentralization reforms can reduce spending volatility by distributing power to sub-central governments, particularly in smaller countries which are usually more prone to volatility
Can fiscal decentralization alleviate government consumption volatility?
We analyse how fiscal decentralization affects the volatility of government consumption extending the existing literature that mainly deals with the effects of the former on government size. Using data for 97 developed and developing countries from 1971 to 2010, we find that a higher degree of fiscal decentralization leads to lower government consumption volatility. This result holds for the sub-sample of advanced economies, while it is not confirmed for those less-developed. This mechanism seems to work mainly through a lower volatility of the non-discretionary spending, which typically belongs to the central government’s policy. We also confirm existing findings according to which country size lowers government spending volatility. Thus, given a minimum level of development, fiscal decentralization reforms can reduce spending volatility by distributing power to sub-central governments, particularly in smaller countries which are usually more prone to volatility
Drosophila Helical factor is an inducible protein acting as an immune-regulated cytokine in S2 cells.
The innate immunity of Drosophila melanogaster is based on cellular and humoral components. Drosophila Helical factor (Hf), is a molecule previously discovered using an in silico approach and whose expression is controlled by the immune deficiency (Imd) pathway. Here we present evidence demonstrating that Hf is an inducible protein constitutively produced by the S2 hemocyte-derived cell line. Hf expression is stimulated by bacterial extracts that specifically trigger the Imd pathway. In absence of any bacterial challenge, the recombinant form of Hf can influence the expression of the antimicrobial peptides (AMPs) defensin but not drosomycin. These data suggest that in vitro Hf is an inducible and immune-regulated factor, with functions comparable to those of secreted vertebrate cytokine
Wet deposition at the base of Mt Everest: Seasonal evolution of the chemistry and isotopic composition
The chemistry of wet deposition was investigated during 2012–2014 at the Pyramid International Laboratory in the Upper Khumbu Valley, Nepal, at 5050 m a.s.l., within the Global Atmosphere Watch (GAW) programme. The main hydro-chemical species and stable isotopes of the water molecule were determined for monsoon rain (July–September) and snow samples (October–June). To evaluate the synoptic-scale variability of air masses reaching the measurement site, 5 day back-trajectories were computed for the sampling period. Ion concentrations in precipitation during the monsoon were low suggesting that they represent global regional background concentrations. The associations between ions suggested that the principal sources of chemical species were marine aerosols, rock and soil dust, and fossil fuel combustion. Most chemical species exhibited a pattern during the monsoon, with maxima at the beginning and at the end of the season, partially correlated with the precipitation amount. Snow samples exhibited significantly higher concentrations of chemical species, compared to the monsoon rainfall observations. Particularly during 2013, elevated concentrations of NO3−, SO42− and NH4+ were measured in the first winter snow event, and in May at the end of the pre-monsoon season. The analysis of large-scale circulation and wind regimes as well as atmospheric composition observations in the region indicates the transport of polluted air masses from the Himalayan foothills and Indian sub-continent up to the Himalaya region. During the summer monsoon onset period, the greater values of pollutants can be attributed to air-mass transport from the planetary boundary layer (PBL) of the Indo-Gangetic plains. Isotopic data confirm that during the monsoon period, precipitation occurred from water vapor that originated from the Indian Ocean and the Bay of Bengal; by contrast during the non-monsoon period, an isotopic signature of more continental origin appeared, indicating that the higher recorded NO3− and SO42− concentrations could be ascribed to a change in air circulation patterns. A comparison of recent monsoon deposition chemistry with data from the 1990's shows similar levels of contaminants in the rainfall. However, non-monsoon deposition can be significant, as it largely contributed to the ion wet deposition fluxes for all analyzed species in 2013
Clodronate Liposome-Mediated Phagocytic Hemocyte Depletion Affects the Regeneration of the Cephalic Tentacle of the Invasive Snail, Pomacea canaliculata
After amputation, granular hemocytes infiltrate the blastema of regenerating cephalic
tentacles of the freshwater snail Pomacea canaliculata. Here, the circulating phagocytic hemocytes were chemically depleted by injecting the snails with clodronate liposomes, and the effects on the cephalic tentacle regeneration onset and on Pc-Hemocyanin, Pc-transglutaminase (Pc-TG) and Pc-Allograft Inflammatory Factor-1 (Pc-AIF-1) gene expressions were investigated. Flow cytometry analysis demonstrated that clodronate liposomes targeted large circulating hemocytes, resulting in a transient decrease in their number. Corresponding with the phagocyte depletion, tentacle regeneration onset
was halted, and it resumed at the expected pace when clodronate liposome effects were no longer visible. In addition to the regeneration progress, the expressions of Pc-Hemocyanin, Pc-TG, and Pc-AIF-1, which are markers of hemocyte-mediated functions like oxygen transport and immunity, clotting, and inflammation, were modified. After the injection of clodronate liposomes, a specific computer-assisted image analysis protocol still evidenced the presence of granular hemocytes in the tentacle blastema. This is consistent with reports indicating the large and agranular hemocyte population as the most represented among the professional phagocytes of P. canaliculata and with the hypothesis that different hemocyte morphologies could exert diverse biological functions, as it has been observed in other invertebrates
Pulmonary artery elastance as a predictor of hospital mortality in heart failure cardiogenic shock
Aims The initial bundle of cares strongly affects haemodynamics and outcomes in acute decompensated heart failure cardiogenic shock (ADHF-CS). We sought to characterize whether 24 h haemodynamic profiling provides superior prognostic information as compared with admission assessment and which haemodynamic parameters best predict in-hospital death. Methods and results All patients with ADHF-CS and with available admission and 24 h invasive haemodynamic assessment from two academic institutions were considered for this study. The primary endpoint was in-hospital death. Regression analyses were run to identify relevant predictors of study outcome. We included 127 ADHF-CS patients [65 (inter-quartile range 52-72) years, 25.2% female]. Overall, in-hospital mortality occurred in 26.8%. Non-survivors were older, with greater CS severity. Among admission variables, age [odds ratio (OR) = 1.06; 95% confidence interval (CI): 1.02-1.11; P-adj = 0.005] and CPIRAP (OR = 0.62 for 0.1 increment; 95% CI: 0.39-0.95; P-adj = 0.034) were found significantly associated with in-hospital death. Among 24 h haemodynamic univariate predictors of in-hospital death, pulmonary elastance (PaE) was the strongest (area under the curve of 0.77; 95% CI: 0.68-0.86). PaE (OR = 5.98; 95% CI: 2.29-17.48; P-adj < 0.001), pulmonary artery pulsatility index (PAPi, OR = 0.77; 95% CI: 0.62-0.92; P-adj = 0.013) and age (OR = 1.06; 95% CI: 1.02-1.11; P-adj = 0.010) were independently associated with in-hospital death. Best cut-off for PaE was 0.85 mmHg/mL and for PAPi was 2.95; cohort phenotyping based on these PaE and PAPi thresholds further increased in-hospital death risk stratification; patients with 24 h high PaE and low PAPi exhibited the highest in-hospital mortality (56.2%). Conclusions Pulmonary artery elastance has been found to be the most powerful 24 h haemodynamic predictor of in-hospital death in patients with ADHF-CS. Age, 24 h PaE, and PAPi are independently associated with hospital mortality. PaE captures right ventriclar (RV) afterload mismatch and PAPi provides a metric of RV adaptation, thus their combination generates four distinct haemodynamic phenotypes, enhancing in-hospital death risk stratification
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