71 research outputs found

    Zamke za nositelje naboja u stupnjevanim InGaAS fotodiodama s velikim sadržajem indija

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    Carrier traps in In0.82Ga0.18As, introduced during manufacturing of photodiodes by vapour phase epitaxy (VPE), have been studied by electrical measurements. Two groups of localized energy levels associated with traps were found in photodiodes annealed at higher temperature after fabrication: the first, at Ec- 0.14 eV, and the second located deeper, close to the middle of the energy gap. Electrically activated dislocations by association with some impurities are responsible for the occurrence of the deeper levels.Električnim mjerenjima istražena su svojstva zamki za nositelje naboja koje nastaju pri izradi fotodioda iz In0.82Ga0.18As metodom epitaksijalnog rasta iz parne faze (VPE). U fotodiodama, koje su naknadno napuštane nakon izrade na povišenoj temperaturi, zapažene su dvije skupine lokaliziranih nivoa zamki: jedan plići na Ec − 0, 14 eV i druge dublje nešto ispod sredine zabranjenog energijskog pojasa. Ustanovljeno je da su električki aktivirane dislokacije primjesama odgovorne za pojavu dubljih nivoa

    Connecting the Dots: Livestock Animals as Missing Links in the Chain of Microplastic Contamination and Human Health

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    Plastic pollution is a global diffuse threat, especially considering its fragmentation into microplastics (MPs) and nanoplastics (NPs). Since the contamination of the aquatic environment is already well studied, most studies have now focused on the soil. Moreover, the number of studies on the exposure routes and toxic effects of MNPs in humans is continuously increasing. Although MNPs can cause inflammation, cytotoxicity, genotoxicity and immune toxicity in livestock animals, which can accumulate ingested/inhaled plastic particles and transfer them to humans through the food chain, research on this topic is still lacking. In considering farm animals as the missing link between soil/plant contamination and human health effects, this paper aims to describe their importance as carriers and vectors of MNP contamination. As research on this topic is in its early stages, there is no standard method to quantify the amount and the characteristics of MNPs in different matrices. Therefore, the creation of a common database where researchers can report data on MNP characteristics and quantification methods could be helpful for both method standardization and the future training of an AI tool for predicting the most abundant/dangerous polymer(s), thus supporting policy decisions to reduce plastic pollution and perfectly fitting with One Health principles

    Environmental Factors Affecting the Reproductive Efficiency of Italian Simmental Young Bulls

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    The objectives of the study aimed to evaluate the effect of weather conditions and scrotal circumference (SC) on standard semen characteristics of Italian Simmental young bulls (n = 577), all raised in the same performance station and sampled by the artificial vagina (AV) method. Considering the increasing SC, the results showed a significant increase in quantitative semen parameters (p < 0.05 and p < 0.0001, for sperm concentration and total number of spermatozoa, respectively); for every extra centimeter of SC, 17.5 × 106 spermatozoa/mL and 0.102 × 109 of total spermatozoa were produced. The age of the animal at semen collection (395 and 465 days) had similar positive effects. The effect of the average temperature humidity index (THI limits ≤ 40 and ≥70) in the previous 60, 30, and 10 days before the semen collection was also considered. Sixty days before the semen collection, the increasing THI increased both primary (p < 0.0001) and secondary (p < 0.0001) abnormalities while the percentage of morphologically normal spermatozoa decreased (p < 0.0001). Thirty and ten days before collection, the same effect on morphological traits was maintained, but total and progressive motility was also influenced (p < 0.01) with an unexpected increasing pattern. Thus, environmental conditions can influence semen quality during the entire spermatogenesis and results can guide future research on this breed

    In vitro and ex vivo effect of hyaluronic acid on erythrocyte flow properties

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    <p>Abstract</p> <p>Background</p> <p>Hyaluronic acid (HA) is present in many tissues; its presence in serum may be related to certain inflammatory conditions, tissue damage, sepsis, liver malfunction and some malignancies. In the present work, our goal was to investigate the significance of hyaluronic acid effect on erythrocyte flow properties. Therefore we performed <it>in vitro </it>experiments incubating red blood cells (RBCs) with several HA concentrations. Afterwards, in order to corroborate the pathophysiological significance of the results obtained, we replicated the <it>in vitro </it>experiment with <it>ex vivo </it>RBCs from diagnosed rheumatoid arthritis (RA) patients, a serum HA-increasing pathology.</p> <p>Methods</p> <p>Erythrocyte deformability (by filtration through nucleopore membranes) and erythrocyte aggregability (EA) were tested on blood from healthy donors additioned with purified HA. EA was measured by transmitted light and analyzed with a mathematical model yielding two parameters, the aggregation rate and the size of the aggregates. Conformational changes of cytoskeleton proteins were estimated by electron paramagnetic resonance spectroscopy (EPR).</p> <p>Results</p> <p><it>In vitro</it>, erythrocytes treated with HA showed increased rigidity index (RI) and reduced aggregability, situation strongly related to the rigidization of the membrane cytoskeleton triggered by HA, as shown by EPR results. Also, a significant correlation (r: 0.77, p < 0.00001) was found between RI and serum HA in RA patients.</p> <p>Conclusions</p> <p>Our results lead us to postulate the hypothesis that HA interacts with the erythrocyte surface leading to modifications in erythrocyte rheological and flow properties, both <it>ex vivo </it>and <it>in vitro</it>.</p

    Domain Specific Languages for Managing Feature Models: Advances and Challenges

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    International audienceManaging multiple and complex feature models is a tedious and error-prone activity in software product line engineering. Despite many advances in formal methods and analysis techniques, the supporting tools and APIs are not easily usable together, nor unified. In this paper, we report on the development and evolution of the Familiar Domain-Specific Language (DSL). Its toolset is dedicated to the large scale management of feature models through a good support for separating concerns, composing feature models and scripting manipulations. We overview various applications of Familiar and discuss both advantages and identified drawbacks. We then devise salient challenges to improve such DSL support in the near future

    An Empirical Study of Bots in Software Development -- Characteristics and Challenges from a Practitioner's Perspective

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    Software engineering bots - automated tools that handle tedious tasks - are increasingly used by industrial and open source projects to improve developer productivity. Current research in this area is held back by a lack of consensus of what software engineering bots (DevBots) actually are, what characteristics distinguish them from other tools, and what benefits and challenges are associated with DevBot usage. In this paper we report on a mixed-method empirical study of DevBot usage in industrial practice. We report on findings from interviewing 21 and surveying a total of 111 developers. We identify three different personas among DevBot users (focusing on autonomy, chat interfaces, and "smartness"), each with different definitions of what a DevBot is, why developers use them, and what they struggle with. We conclude that future DevBot research should situate their work within our framework, to clearly identify what type of bot the work targets, and what advantages practitioners can expect. Further, we find that there currently is a lack of general purpose "smart" bots that go beyond simple automation tools or chat interfaces. This is problematic, as we have seen that such bots, if available, can have a transformative effect on the projects that use them.Comment: To be published at the ACM Joint European Software Engineering Conference and Symposium on the Foundations of Software Engineering (ESEC/FSE

    Biogeographic distributions of neotropical trees reflect their directly measured drought tolerances

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    High levels of species diversity hamper current understanding of how tropical forests may respond to environmental change. In the tropics, water availability is a leading driver of the diversity and distribution of tree species, suggesting that many tropical taxa may be physiologically incapable of tolerating dry conditions, and that their distributions along moisture gradients can be used to predict their drought tolerance. While this hypothesis has been explored at local and regional scales, large continental-scale tests are lacking. We investigate whether the relationship between drought-induced mortality and distributions holds continentally by relating experimental and observational data of drought-induced mortality across the Neotropics to the large-scale bioclimatic distributions of 115 tree genera. Across the different experiments, genera affiliated to wetter climatic regimes show higher drought-induced mortality than dry-affiliated ones, even after controlling for phylogenetic relationships. This pattern is stronger for adult trees than for saplings or seedlings, suggesting that the environmental filters exerted by drought impact adult tree survival most strongly. Overall, our analysis of experimental, observational, and bioclimatic data across neotropical forests suggests that increasing moisture-stress is indeed likely to drive significant changes in floristic composition

    Topical antibiotics as a major contextual hazard toward bacteremia within selective digestive decontamination studies: a meta-analysis

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    BACKGROUND: Among methods for preventing pneumonia and possibly also bacteremia in intensive care unit (ICU) patients, Selective Digestive Decontamination (SDD) appears most effective within randomized concurrent controlled trials (RCCT’s) although more recent trials have been cluster randomized. However, of the SDD components, whether protocolized parenteral antibiotic prophylaxis (PPAP) is required, and whether the topical antibiotic actually presents a contextual hazard, remain unresolved. The objective here is to compare the bacteremia rates and patterns of isolates in SDD-RCCT’s versus the broader evidence base. METHODS: Bacteremia incidence proportion data were extracted from component (control and intervention) groups decanted from studies investigating antibiotic (SDD) or non-antibiotic methods of VAP prevention and summarized using random effects meta-analysis of study and group level data. A reference category of groups derived from purely observational studies without any prevention method under study provided a benchmark incidence. RESULTS: Within SDD RCCTs, the mean bacteremia incidence among concurrent component groups not exposed to PPAP (27 control; 17.1%; 13.1-22.1% and 12 intervention groups; 16.2%; 9.1-27.3%) is double that of the benchmark bacteremia incidence derived from 39 benchmark groups (8.3; 6.8-10.2%) and also 20 control groups from studies of non-antibiotic methods (7.1%; 4.8 – 10.5). There is a selective increase in coagulase negative staphylococci (CNS) but not in Pseudomonas aeruginosa among bacteremia isolates within control groups of SDD-RCCT’s versus benchmark groups with data available. CONCLUSIONS: The topical antibiotic component of SDD presents a major contextual hazard toward bacteremia against which the PPAP component partially mitigates. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12879-014-0714-x) contains supplementary material, which is available to authorized users
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