Pathologic heart conditions, particularly heart failure (HF) and ischemia-reperfusion (I/R) injury, are characterized by sustained elevation of plasma and interstitial catecholamine levels, as well ...as by the generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS). Despite the continuous and extensive research on catecholamines since the early years of the XX(th) century, the mechanisms underlying catecholamine-induced cardiotoxicity are still not fully elucidated. The role of catecholamines in HF, stress cardiomyopathy, I/R injury, ageing, stress, and pheochromocytoma will be thoroughly discussed. Furthermore and although the noxious effects resulting from catecholamine excess have traditionally been linked to adrenoceptors, in fact, several evidences indicate that oxidative stress and the oxidation of catecholamines can have important roles in catecholamine-induced cardiotoxicity. Accordingly, the reactive intermediates formed during catecholamine oxidation have been associated with cardiac toxicity, both in in vitro and in vivo studies. An insight into the influence of ROS, RNS, and catecholamine oxidation products on several heart diseases and their clinical course will be provided. In addition, the source and type of oxidant species formed in some heart pathologies will be referred. In this review a special focus will be given to the research of cardiac pathologies where catecholamines and oxidative stress are involved. An integrated vision of these matters is required and will be provided along this review, namely how the concomitant surge of catecholamines and ROS occurs and how they can be interconnected. The concomitant presence of these factors can elicit peculiar and not fully characterized responses on the heart. We will approach the existing data with new perspectives as they can help explaining several controversial results regarding cardiovascular diseases and the redox ability of catecholamines.
We perform a spectroscopic study to constrain the stellar initial mass function (IMF) by using a large sample of 24 781 early-type galaxies from the Sloan Digital Sky Survey-based Spheroids ...Panchromatic Investigation in Different Environmental Regions survey. Clear evidence is found of a trend between IMF and central velocity dispersion (σ0), evolving from a standard Kroupa/Chabrier IMF at σ0 ∼ 100 km s−1 towards a more bottom-heavy IMF with increasing σ0, becoming steeper than the Salpeter function at σ0 220 km s−1. We analyse a variety of spectral indices, combining gravity-sensitive features, with age- and metallicity-sensitive indices, and we also consider the effect of non-solar abundance variations. The indices, corrected to solar scale by means of semi-empirical correlations, are fitted simultaneously with the (nearly solar-scaled) extended MILES (MIUSCAT) stellar population models. Similar conclusions are reached when analysing the spectra with a hybrid approach, combining constraints from direct spectral fitting in the optical with those from IMF-sensitive indices. Our analysis suggests that σ0, rather than α/Fe, drives the variation of the IMF. Although our analysis cannot discriminate between a single power-law (unimodal) IMF and a low-mass ( 0.5 M) tapered (bimodal) IMF, robust constraints can be inferred for the fraction in low-mass stars at birth. This fraction (by mass) is found to increase from ∼20 per cent at σ0 ∼ 100 km s−1, up to ∼80 per cent at σ0 ∼ 300 km s−1. However, additional constraints can be provided with stellar mass-to-light (M/L) ratios: unimodal models predict M/L significantly larger than dynamical M/L, across the whole σ0 range, whereas a bimodal IMF is compatible. Our results are robust against individual abundance variations. No significant variation is found in Na and Ca in addition to the expected change from the correlation between α/Fe and σ0.
The end-Cretaceous event was catastrophic for terrestrial communities worldwide, yet its long-lasting effect on tropical forests remains largely unknown. We quantified plant extinction and ecological ...change in tropical forests resulting from the end-Cretaceous event using fossil pollen (>50,000 occurrences) and leaves (>6000 specimens) from localities in Colombia. Late Cretaceous (Maastrichtian) rainforests were characterized by an open canopy and diverse plant-insect interactions. Plant diversity declined by 45% at the Cretaceous-Paleogene boundary and did not recover for ~6 million years. Paleocene forests resembled modern Neotropical rainforests, with a closed canopy and multistratal structure dominated by angiosperms. The end-Cretaceous event triggered a long interval of low plant diversity in the Neotropics and the evolutionary assembly of today's most diverse terrestrial ecosystem.
The use of environmental DNA (eDNA) in biodiversity assessments offers a step-change in sensitivity, throughput and simultaneous measures of ecosystem diversity and function. There remains, however, ...a need to examine eDNA persistence in the wild through simultaneous temporal measures of eDNA and biota. Here, we use metabarcoding of two markers of different lengths, derived from an annual time series of aqueous lake eDNA to examine temporal shifts in ecosystem biodiversity and in an ecologically important group of macroinvertebrates (Diptera: Chironomidae). The analyses allow different levels of detection and validation of taxon richness and community composition (β-diversity) through time, with shorter eDNA fragments dominating the eDNA community. Comparisons between eDNA, community DNA, taxonomy and UK species abundance data further show significant relationships between diversity estimates derived across the disparate methodologies. Our results reveal the temporal dynamics of eDNA and validate the utility of eDNA metabarcoding for tracking seasonal diversity at the ecosystem scale.
ABSTRACT We present an extended morphometric system to automatically classify galaxies from astronomical images. The new system includes the original and modified versions of the CASGM coefficients ...(Concentration C1, Asymmetry A3, and Smoothness S3), and the new parameters entropy, H, and spirality . The new parameters A3, S3, and H are better to discriminate galaxy classes than A1, S1, and G, respectively. The new parameter captures the amount of non-radial pattern on the image and is almost linearly dependent on T-type. Using a sample of spiral and elliptical galaxies from the Galaxy Zoo project as a training set, we employed the Linear Discriminant Analysis (LDA) technique to classify EFIGI (Baillard et al. 4458 galaxies), Nair & Abraham (14,123 galaxies), and SDSS Legacy (779,235 galaxies) samples. The cross-validation test shows that we can achieve an accuracy of more than 90% with our classification scheme. Therefore, we are able to define a plane in the morphometric parameter space that separates the elliptical and spiral classes with a mismatch between classes smaller than 10%. We use the distance to this plane as a morphometric index (Mi) and we show that it follows the human based T-type index very closely. We calculate morphometric index Mi for ∼780k galaxies from SDSS Legacy Survey-DR7. We discuss how Mi correlates with stellar population parameters obtained using the spectra available from SDSS-DR7.
Melanogenesis is a biosynthetic pathway for the formation of the pigment melanin in human skin. A key enzyme in the process of pigmentation through melanin is tyrosinase, which catalyzes the first ...and only limiting step in melanogenesis. Since the discovery of its methanogenic properties, tyrosinase has been the focus of research related to the anti-melanogenesis. In addition to developing more effective and commercially safe inhibitors, more studies are required to better understand the mechanisms involved in the skin depigmentation process. However, in vivo assays are necessary to develop and validate new drugs or molecules for this purpose, and to accomplish this, zebrafish has been identified as a model organism for in vivo application. In addition, such model would allow tracking and studying the depigmenting activity of many bioactive compounds, important to genetics, medicinal chemistry and even the cosmetic industry. Studies have shown the similarity between human and zebrafish genomes, encouraging their use as a model to understand the mechanism of action of a tested compound. Interestingly, zebrafish skin shares many similarities with human skin, suggesting that this model organism is suitable for studying melanogenesis inhibitors. Accordingly, several bioactive compounds reported herein for this model are compared in terms of their molecular structure and possible mode of action in zebrafish embryos. In particular, this article described the main metabolites of
fungi, in addition to substances from natural and synthetic sources.
Bioremediation, involving bioaugmentation and/or biostimulation, being an economical and eco-friendly approach, has emerged as the most advantageous soil and water clean-up technique for contaminated ...sites containing heavy metals and/or organic pollutants. Addition of pre-grown microbial cultures to enhance the degradation of unwanted compounds (bioaugmentation) and/or injection of nutrients and other supplementary components to the native microbial population to induce propagation at a hastened rate (biostimulation), are the most common approaches for in situ bioremediation of accidental spills and chronically contaminated sites worldwide. However, many factors like strain selection, microbial ecology, type of contaminant, environmental constraints, as well as procedures of culture introduction, may lead to their failure. These drawbacks, along with fragmented literature, have opened a gap between laboratory trials and on-field application. The present review discusses the effectiveness as well as the limitations of bioaugmentation and biostimulation processes. A summary of experimental studies both in confined systems under controlled conditions and of real case studies in the field is presented. A comparative account between the two techniques and also the current scenario worldwide for in situ biotreatment using bioaugmentation and biostimulation, are addressed.
Tropical Southeast (SE) Asia harbors extraordinary species richness and in its entirety comprises four of the Earth's 34 biodiversity hotspots. Here, we examine the assembly of the SE Asian biota ...through time and space. We conduct meta-analyses of geological, climatic, and biological (including 61 phylogenetic) data sets to test which areas have been the sources of long-term biological diversity in SE Asia, particularly in the pre-Miocene, Miocene, and Plio-Pleistocene, and whether the respective biota have been dominated by in situ diversification, immigration and/or emigration, or equilibrium dynamics. We identify Borneo and Indochina, in particular, as major "evolutionary hotspots" for a diverse range of fauna and flora. Although most of the region's biodiversity is a result of both the accumulation of immigrants and in situ diversification, within-area diversification and subsequent emigration have been the predominant signals characterizing Indochina and Borneo's biota since at least the early Miocene. In contrast, colonization events are comparatively rare from younger volcanically active emergent islands such as Java, which show increased levels of immigration events. Few dispersal events were observed across the major biogeographic barrier of Wallace's Line. Accelerated efforts to conserve Borneo's flora and fauna in particular, currently housing the highest levels of SE Asian plant and mammal species richness, are critically required.
Purpose
To quantify the physical activity in daily life (PADL), muscle strength, and exercise capacity in the short and medium term in survivors of severe sepsis and septic shock.
Methods
Prospective ...cohort study with a follow-up from hospital admission to 3 months after hospital discharge. Seventy-two patients admitted to the ICU for severe sepsis or septic shock and a control group of healthy sedentary subjects (
n
= 50) were enrolled. All patients had their PADL quantified by an accelerometer during their hospital stay and 3 months after. Exercise capacity and handgrip and quadriceps muscle strength were also evaluated.
Results
During hospitalization, patients spent the majority of their time inactive in a lying or sitting position (90 ± 34 % of daily time). Physical inactivity was partially reduced 3 months after (58 ± 20 % of daily time). However, the time patients spent walking was only 63 % of the time reported for healthy subjects. Patients also showed lower movement intensity when compared with controls (2.1 ± 0.3 vs 2.5 ± 0.4 m/s
2
). At hospital discharge, muscle strength and exercise capacity were approximately 54 % of the predicted value, and these parameters showed significant increase in patients 3 months after (70 % of predicted value). Multivariable analysis demonstrated that the use of systemic corticosteroids and hospitalization time negatively influenced quadriceps strength and exercise capacity at the time of hospital discharge.
Conclusion
Our results suggest that survivors of sepsis admitted to the ICU have a substantial reduction in physical activity, exercise capacity, and muscle strength compared to healthy subjects that persist even 3 months after hospital discharge.
Automatic monitoring of biodiversity by acoustic sensors has become an indispensable tool to assess environmental stress at an early stage. Due to the difficulty in recognizing the Amazon's high ...acoustic diversity and the large amounts of raw audio data recorded by the sensors, the labeling and manual inspection of this data is not feasible. Therefore, we propose an ecoacoustic index that allows us to quantify the complexity of an audio segment and correlate this measure with the biodiversity of the soundscape. The approach uses unsupervised methods to avoid the problem of labeling each species individually. The proposed index, named the Ecoacoustic Global Complexity Index (EGCI), makes use of Entropy, Divergence and Statistical Complexity. A distinguishing feature of this index is the mapping of each audio segment, including those of varied lengths, as a single point in a 2D-plane, supporting us in understanding the ecoacoustic dynamics of the rainforest. The main results show a regularity in the ecoacoustic richness of a floodplain, considering different temporal granularities, be it between hours of the day or between consecutive days of the monitoring program. We observed that this regularity does a good job of characterizing the soundscape of the environmental protection area of Mamirauá, in the Amazon, differentiating between species richness and environmental phenomena.
PDF
