43 research outputs found
Multiprocessing techniques for unmanned multifunctional satellites Final report,
Simulation of on-board multiprocessor for long lived unmanned space satellite contro
Risk Factors Associated with Adverse Fetal Outcomes in Pregnancies Affected by Coronavirus Disease 2019 (COVID-19): A Secondary Analysis of the WAPM study on COVID-19
To evaluate the strength of association between maternal and pregnancy characteristics and the risk of adverse perinatal outcomes in pregnancies with laboratory confirmed COVID-19. Secondary analysis of a multinational, cohort study on all consecutive pregnant women with laboratory-confirmed COVID-19 from February 1, 2020 to April 30, 2020 from 73 centers from 22 different countries. A confirmed case of COVID-19 was defined as a positive result on real-time reverse-transcriptase-polymerase-chain-reaction (RT-PCR) assay of nasal and pharyngeal swab specimens. The primary outcome was a composite adverse fetal outcome, defined as the presence of either abortion (pregnancy loss before 22 weeks of gestations), stillbirth (intrauterine fetal death after 22 weeks of gestation), neonatal death (death of a live-born infant within the first 28 days of life), and perinatal death (either stillbirth or neonatal death). Logistic regression analysis was performed to evaluate parameters independently associated with the primary outcome. Logistic regression was reported as odds ratio (OR) with 95% confidence interval (CI). Mean gestational age at diagnosis was 30.6\ub19.5 weeks, with 8.0% of women being diagnosed in the first, 22.2% in the second and 69.8% in the third trimester of pregnancy. There were six miscarriage (2.3%), six intrauterine device (IUD) (2.3) and 5 (2.0%) neonatal deaths, with an overall rate of perinatal death of 4.2% (11/265), thus resulting into 17 cases experiencing and 226 not experiencing composite adverse fetal outcome. Neither stillbirths nor neonatal deaths had congenital anomalies found at antenatal or postnatal evaluation. Furthermore, none of the cases experiencing IUD had signs of impending demise at arterial or venous Doppler. Neonatal deaths were all considered as prematurity-related adverse events. Of the 250 live-born neonates, one (0.4%) was found positive at RT-PCR pharyngeal swabs performed after delivery. The mother was tested positive during the third trimester of pregnancy. The newborn was asymptomatic and had negative RT-PCR test after 14 days of life. At logistic regression analysis, gestational age at diagnosis (OR: 0.85, 95% CI 0.8-0.9 per week increase; p<0.001), birthweight (OR: 1.17, 95% CI 1.09-1.12.7 per 100 g decrease; p=0.012) and maternal ventilatory support, including either need for oxygen or CPAP (OR: 4.12, 95% CI 2.3-7.9; p=0.001) were independently associated with composite adverse fetal outcome. Early gestational age at infection, maternal ventilatory supports and low birthweight are the main determinants of adverse perinatal outcomes in fetuses with maternal COVID-19 infection. Conversely, the risk of vertical transmission seems negligible
Plant Species\u27 Origin Predicts Dominance and Response to Nutrient Enrichment and Herbivores in Global Grasslands
Exotic species dominate many communities; however the functional significance of species\u27 biogeographic origin remains highly contentious. This debate is fuelled in part by the lack of globally replicated, systematic data assessing the relationship between species provenance, function and response to perturbations. We examined the abundance of native and exotic plant species at 64 grasslands in 13 countries, and at a subset of the sites we experimentally tested native and exotic species responses to two fundamental drivers of invasion, mineral nutrient supplies and vertebrate herbivory. Exotic species are six times more likely to dominate communities than native species. Furthermore, while experimental nutrient addition increases the cover and richness of exotic species, nutrients decrease native diversity and cover. Native and exotic species also differ in their response to vertebrate consumer exclusion. These results suggest that species origin has functional significance, and that eutrophication will lead to increased exotic dominance in grasslands
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Plant species' origin predicts dominance and response to nutrient enrichment and herbivores in global grasslands
Exotic species dominate many communities; however the functional significance of species’ biogeographic origin remains highly contentious. This debate is fuelled in part by the lack of globally replicated, systematic data assessing the relationship between species provenance, function and response to perturbations. We examined the abundance of native and exotic plant species at 64 grasslands in 13 countries, and at a subset of the sites we experimentally tested native and exotic species responses to two fundamental drivers of invasion, mineral nutrient supplies and vertebrate herbivory. Exotic species are six times more likely to dominate communities than native species. Furthermore, while experimental nutrient addition increases the cover and richness of exotic species, nutrients decrease native diversity and cover. Native and exotic species also differ in their response to vertebrate consumer exclusion. These results suggest that species origin has functional significance, and that eutrophication will lead to increased exotic dominance in grasslands
Continuous Simulation of the Power Flow in AC–DC Hybrid Microgrids Using Simplified Modelling
This paper reports the development of a model for continuous simulation of the power flow into AC–DC hybrid microgrids operating for different generation–consumption scenarios. The proposed application was assembled using a multiple-input multiple-output model which was built using blocks containing simplified models of photovoltaic (PV) modules, wind turbines (WT), battery arrays (energy storage units, ESU), and power loads. The average power was used as the input/output variable of the blocks, allowing flexibility for easy reconfiguration of the microgrid and its control. By defining a generation profile, PV and WT were modeled considering environmental conditions and efficiency profiles of the maximum power point tracking (MPPT) algorithms. ESUs were modeled from intrinsic characteristics of the batteries, considering a constant power charge regime and using the State of Energy (SoE) approach to compute autonomy. To define a consumption profile, DC and AC loads were modeled as a constant real power. As an innovative characteristic, unidirectional and bidirectional power conversion stages were modeled using efficiency profiles, which can be obtained from experiments applied to the real converters. The outputs of the models of generation, consumption, and storage units were integrated as inputs of the mathematical expressions computing the power balance of the buses of the microgrid. The proposed model is suitable to analyze efficiency for different configurations of the same microgrid architecture, and can be extended by integrating additional elements. The model was implemented in LabVIEW software and three examples were developed to test its correct operation
Operating performance of manual, semi-automatic, and automatic tractor guidance systems for precision farming
Effect of the Current Antimicrobial Therapeutic Strategy on Fungal Colonization in Patients with Hematologic Malignancies
A "quasi-experimental" trial was carried out to investigate the effect of three antimicrobial regimens on oral and fecal yeast colonization in patients with hematologic malignancies. Fifty-four patients received ciprofloxacin and oral amphotericin B (group 1); 45 received ceftazidime, amikacin, vancomycin, and oral amphotericin B (group 2); and 30 received ceftazidime, amikacin, vancomycin, and intravenous amphotericin B (group 3). The oral yeast isolation rate showed a decrease in group 1 (from 59.3% to 40.7%) and group 3 (from 56.7% to 46.7%), and a marked increase in group 2 (from 51.1% to 84. 4%). All the groups showed a reduction in their fecal yeast isolation rate. An overgrowth of Candida parapsilosis, C. krusei, and C. tropicalis was observed in all the groups, but it was much higher in group 2. Our findings provide evidence that ceftazidime, amikacin, and vancomycin, given with oral amphotericin B, induce an overgrowth/persistence of Candida species in the mouth and gut, which might be attributable to inclusion of vancomycin. Treatment with intravenous amphotericin B has at least the capacity of counterbalancing yeast proliferation induced by that antibacterial regimen