HF and VHF communications circuits - Earth orbiting spacecraft and ground stations

HF and VHF communications circuits for Earth orbiting spacecraft and ground station

Influence Of Fish Presence And Removal On Woodland Pond Breeding Amphibians

U okviru rada izrađena je programska potpora te provedeno istraživanje učenja programskih koncepata korištenjem blokova. Ispitivanje je provedeno nad učenicima prvog razreda osnovne škole koji su korištenjem programske potpore rješavali problemske zadatke prikladne njihovoj dobi. Zadatci su podijeljeni u četiri skupine od kojih je svaka povezana s gradivom određenih predmeta, a svaka od njih ispituje različite programske koncepte algoritamsko-računalnog načina razmišljanja. Radom je dan pregled razvoja korištene aplikacije, od postavljanja zahtjeva do implementacije koja je usko vezana uz pojedine programske biblioteke i okvire. Predložena su poboljšanja te su dani savjeti za razvoj sličnog rješenja. Ispitivanje je pokazalo korelacije među nekim općenitim pokazateljima uspješnosti, ali na generalnoj razini ne postoji povezanost zadataka sa procjenom matematičke i logičke vještine ispitanika.For the purpose of analysing how well students use basic programming concepts, a research was conducted using custom-built application software. The tested students were enrolled in the first grade of primary school and had to solve problem tasks using predefined blocks which represented certain programming concepts. Problem tasks were divided into four groups depending on which concept was tested as well as which course its problem was related to. Each experiment tested one problem task group and consisted of students using the custom-built application to solve its problems. The thesis describes in detail the development process of the created software as well as points out certain design decisions that it, and similar solutions, should have. The research showed that among some variables there is significant correlation, but generally it was found that defined success variables aren’t connected to the mathematical and logical skill assessment

Multicomposition EPSR: toward transferable potentials to model chalcogenide glass structures

The structure of xAs40Se60–(1 – x)As40S60 glasses, where x = 1.000, 0.667, 0.500, 0.333, 0.250, and 0.000, is investigated using a combination of neutron and X-ray diffraction coupled with computational modeling using multicomposition empirical potential structure refinement (MC-EPSR). Traditional EPSR (T-EPSR) produces a set of empirical potentials that drive a structural model of a particular composition to agreement with diffraction experiments. The work presented here establishes the shortcomings in generating such a model for a ternary chalcogenide glass composition. In an enhancement to T-EPSR, MC-EPSR produces a set of pair potentials that generate robust structural models across a range of glass compositions. The structures obtained vary with composition in a much more systematic way than those taken from T-EPSR. For example, the average arsenic–sulfur bonding distances vary between 2.28 and 2.46 Å in T-EPSR but are 2.29 ± 0.02 Å in MC-EPSR. Similarly, the arsenic–selenium bond lengths from T-EPSR vary between 2.28 and 2.43 Å but are consistently 2.40 ± 0.02 Å in the MC-EPSR results. Analysis of these models suggests that the average separation of the chalcogen (S or Se) atoms is the structural origin of the changes in nonlinear refractive index with glass composition

Alexander of Aphrodisias On Aristotle On Sense Perception

The first English translation of the commentary of Alexander of Aphrodisias on Aristotle's De Sensu.With notes

Protocol for a case-control prospective study to investigate the impact of Hepatic Encephalopathy on Nutritional Intake and Sarcopenia status in patients with end-stage LIVer disease:HENS-LIV study

INTRODUCTION: Hepatic encephalopathy (HE) is a debilitating symptom of end-stage liver disease (ESLD), but there remains a paucity of evidence regarding its impact on nutritional status, nutritional intake, compliance with nutritional support and resultant muscle health and function. Malnutrition and sarcopenia are associated with increased morbidity and mortality in patients with ESLD. The aim of the current case–control study is to prospectively investigate the impact of HE on nutritional intake and sarcopenia status in patients with ESLD. METHODS AND ANALYSIS: Patients with ESLD, with HE (n=10) and without HE (n=10) will be recruited at the outpatient liver unit, University Hospital Birmingham, UK. All patients will undergo clinical assessment at baseline and again at 6–8 weeks (in-line with their routine clinical follow-up), to assess the impact of HE on reported nutritional intake, nutritional status and sarcopenia/physical functional status. Standard medical, dietetic and home-based exercise physiotherapy care will continue for all participants as determined by their clinical team. Two methods of assessing nutritional intake will include the 24-hour food recall and 3-day food diaries. Assessment of sarcopenia status will be undertaken using anthropometry (mid-arm muscle circumference (MAMC)) and ultrasound imaging of the quadriceps muscle group. Markers of physical function (hand grip strength; chair rise time), frailty (Liver Frailty Index (LFI)), physical activity (accelerometery) and exercise capacity (Duke Activity Status Index (DASI)) will be assessed at both clinic visits. ETHICS AND DISSEMINATION: The study is approved by Wales Research Ethics Committee 2 and Health Research Authority (REC reference: 21/WA/0216). Recruitment into the study commenced November 2021. The findings will be disseminated through peer-reviewed publications and international presentations. TRIAL REGISTRATION NUMBER: RRK7156

Low-Density Water Structure Observed in a Nanosegregated Cryoprotectant Solution at Low Temperatures from 285 to 238 K

The structure of liquid water is defined by its molecular association through hydrogen bonding. Two different structures have been proposed for liquid water at low temperatures: low-density liquid (LDL) and high-density liquid (HDL) water. Here, we demonstrate a platform that can be exploited to experimentally probe the structure of liquid water in equilibrium at temperatures down to 238 K. We make use of a cryoprotectant molecule, glycerol, that, when mixed with water, lowers the freezing temperature of the solution nonmonotonically with glycerol concentration. We use a combination of neutron diffraction measurements and computational modeling to examine the structure of water in glycerol–water liquid mixtures at low temperatures from 285 to 238 K. We confirm that the mixtures are nanosegregated into regions of glycerol-rich and water-rich clusters. We examine the water structure and reveal that, at the temperatures studied here, water forms a low-density water structure that is more tetrahedral than the structure at room temperature. We postulate that nanosegregation allows water to form a low-density structure that is protected by an extensive and encapsulating glycerol interface

Assisted Diagnosis of Parkinsonism Based on the Striatal Morphology

Parkinsonism is a clinical syndrome characterized by the progressive loss of striatal dopamine. Its diagnosis is usually corroborated by neuroimaging data such as DaTSCAN neuroimages that allow visualizing the possible dopamine deficiency. During the last decade, a number of computer systems have been proposed to automatically analyze DaTSCAN neuroimages, eliminating the subjectivity inherent to the visual examination of the data. In this work, we propose a computer system based on machine learning to separate Parkinsonian patients and control subjects using the size and shape of the striatal region, modeled from DaTSCAN data. First, an algorithm based on adaptative thresholding is used to parcel the striatum. This region is then divided into two according to the brain hemisphere division and characterized with 152 measures, extracted from the volume and its three possible 2-dimensional projections. Afterwards, the Bhattacharyya distance is used to discard the least discriminative measures and, finally, the neuroimage category is estimated by means of a Support Vector Machine classifier. This method was evaluated using a dataset with 189 DaTSCAN neuroimages, obtaining an accuracy rate over 94%. This rate outperforms those obtained by previous approaches that use the intensity of each striatal voxel as a feature.This work was supported by the MINECO/ FEDER under the TEC2015-64718-R project, the Ministry of Economy, Innovation, Science and Employment of the Junta de Andaluc´ıa under the P11-TIC-7103 Excellence Project and the Vicerectorate of Research and Knowledge Transfer of the University of Granada