448 research outputs found
Stratigraphy and paleoenvironments of the early to middle Holocene Chipalamawamba Beds (Malawi Basin, Africa)
We describe the Chipalamawamba Beds, early to middle Holocene deposits at the southern margin of long-lived Lake Malawi. The beds are exposed because of downcutting of the upper Shire River. The Chipalamawamba sediments are medium to coarse, yellow to brown sands deposited in lenses varying in horizontal extent from a few meters to several hundreds of meters. Four units are recognized; the first three mainly contain lacustrine sediments deposited during lake high stands about 10.6–9.7 cal ka BP (Unit 1), 7.6–6.5 cal ka BP (Unit 2) and 5.9–5.3 cal ka BP (Unit 3). Sediments of Unit 4 overlay Units 1 to 3, are coarser and display regular foresets and oblique-bedding, suggesting deposition in riverine environments after installation of the Shire River (~ 5.5–5.0 ka BP). Freshwater mollusk assemblages and bioturbation regularly occur in the lacustrine sediments, but are largely absent from Unit 4. Diverse and often contradicting hypotheses on the lake levels of Lake Malawi have been proposed for the early and middle Holocene. The Chipalamawamba Beds allow straightforward recognition of water levels and provide strong evidence for oscillating lake levels during this period, rather than continuous high or low levels. Sedimentation rates have been high and individual shell beds have typically been deposited during a few decades. Because the Chipalamawamba Beds contain a sequence of mollusk assemblages with intervals between subsequent shell beds ranging from a century to a few millennia, they enable paleontological analysis of the fauna with an unusually high temporal resolution. That some mollusk lineages inhabiting Lake Malawi are in the early stages of diversification and radiation increases the paleobiological relevance of these beds
A low-energy rate-adaptive bit-interleaved passive optical network
Energy consumption of customer premises equipment (CPE) has become a serious issue in the new generations of time-division multiplexing passive optical networks, which operate at 10 Gb/s or higher. It is becoming a major factor in global network energy consumption, and it poses problems during emergencies when CPE is battery-operated. In this paper, a low-energy passive optical network (PON) that uses a novel bit-interleaving downstream protocol is proposed. The details about the network architecture, protocol, and the key enabling implementation aspects, including dynamic traffic interleaving, rate-adaptive descrambling of decimated traffic, and the design and implementation of a downsampling clock and data recovery circuit, are described. The proposed concept is shown to reduce the energy consumption for protocol processing by a factor of 30. A detailed analysis of the energy consumption in the CPE shows that the interleaving protocol reduces the total energy consumption of the CPE significantly in comparison to the standard 10 Gb/s PON CPE. Experimental results obtained from measurements on the implemented CPE prototype confirm that the CPE consumes significantly less energy than the standard 10 Gb/s PON CPE
Beyond 'Trimming the fat': the sub-editing stage of newswriting
Thus far, professional editing has not been researched extensively in writing research. This article zooms in on sub-editing in newswriting as a form of professional editing, addressing three research questions: (a) What are the ways in which a news article's text is altered?, (b) Are some types of news article altered more significantly than others?, and (c) Are certain news article sections more prone to alterations? Merging the contextualized insights of fieldwork with a corpus-based discourse analytic research perspective, we trace the differences (viz. additions, deletions, translocations, replacements) between the initial (right before sub-editing) and final (published) version of six different types of news article, (frontpage, headline, long, medium, short, and news wire article) in a corpus sample of 30 broadsheet articles. Our findings are first thatcontrary to popular belief that sub-editors mainly hack away at news stories, or merely trim the fatadditions prevail. Second, we found that most interventions occur in high-stakes articles. Third, we discovered the largest number of interventions in the entry points of an article, that is, whereaccording to eye-tracking researchreaders stop scanning and start reading. We discuss our findings in the light of training for professional newswriters
Minimally invasive atrioventricular valve surgery – current status and future perspectives
We are currently witnessing rapid evolution in minimally invasive and catheter-based atrioventricular valve interventions as acceptable alternatives to classic sternotomy access (CSA). Collectively, minimally invasive atrioventricular valve surgery (MIAS) is associated with significant learning curves and its routine application is met with varying degrees of enthusiasm in view of strict quality control, clinical governance and outcome reporting. Whether the reported potential benefits and comparable efficacy across a range of long-term outcome measures reported by experienced MIAS centres can be translated into general international surgical practice, are not well defined. This paper describes the historic evolution of MIAS, the contemporary clinical outcomes of MIAS compared with CSA, and the application of MIAS in “real-life” general practice
Exploring the potential of virtual reality in patient education:The case of chronic kidney patients
Background: The rapid evaluation of virtual reality (VR) has allowed novel and creative solutions across clinical medicine. Yet, VR has not been used for the purpose of patient education. Studies have shown that 40-80% of the information provided by healthcare practitioners is forgotten by patients immediately. VR may have various benefits such as better information processing and recall due to more absorption and less distraction.Aim: To evaluate a VR-intervention to educate kidney patients about peritoneal dialysis, a type of dialysis that can be conducted at home.Method: Pre-dialysis kidney patients (n=23, average age 67) were exposed to a VR-intervention and subsequently interviewed about their experiences and the (self-perceived) impact it had on their knowledge and reassurance/anxiety about the treatment. All interviews were transcribed verbatim and analysed with two independent coders, using inductive analysis.Results: The majority of patients positively appreciated the VR-intervention. Patients mentioned being less distracted and more focused on the information in the VR-intervention. One-third of the patients mentioned that VR had no added value to inform them about peritoneal dialysis. Most patients stated that the VR-education had a positive impact on their knowledge. While the VR-education was reassuring for most patients, some indicated that the intervention had actually increased their worries and insecurities.Conclusion: Patient education by VR seems to be acceptable to most patients and may help to improve information processing and recall of medical information. It can be reassuring for some patients, but may also be frightening. More quantitative and experimental research is needed.The OOH demo will be introduced, participants can experience how a health technology can offer support in the prevention and control of zoonotic diseases. For example, the visitor can look up specific information by using the chatbot (part of the Q&A system) or the visitor can play the serious game in order to understand the complexity of decision making during zoonotic outbreaks. Demo presenters provide background information about the development process of the OHH
Performance related factors are the main determinants of the von Willebrand factor response to exhaustive physical exercise
Background: Physical stress triggers the endothelium to release von Willebrand Factor (VWF) from the Weibel Palade bodies. Since VWF is a risk factor for arterial thrombosis, it is of great interest to discover determinants of VWF response to physical stress. We aimed to determine the main mediators of the VWF increase by exhaustive physical exercise. Methods: 105 healthy individuals (18-35 years) were included in this study. Each participant performed an incremental exhaustive exercise test on a cycle ergometer. Respiratory gas exchange measurements were obtained while cardiac function was continuously monitored. Blood was collected at baseline and directly after exhaustion. VWF antigen (VWF:Ag) levels, VWF collagen binding (VWF:CB) levels, ADAMTS13 activity and common variations in Syntaxin Binding Protein-5 (STXBP5, rs1039084 and rs9399599), Syntaxin-2 (STX2, rs7978987) and VWF (promoter, rs7965413) were determined. Results: The median VWF:Ag level at baseline was 0.94 IU/mL [IQR 0.8-1.1] and increased with 47% [IQR 25-73] after exhaustive exercise to a median maximum VWF:Ag of 1.38 IU/mL [IQR 1.1-1.8] (p<0.0001). VWF:CB levels and ADAMTS13 activity both also increased after exhaustive exercise (median increase 43% and 12%, both p<0.0001). The strongest determinants of the VWF:Ag level increase are performance related (p<0.0001). We observed a gender difference in VWF:Ag response to exercise (females 1.2 IU/mL; males 1.7 IU/mL, p = 0.001), which was associated by a difference in performance. Genetic variations in STXBP5, STX2 and the VWF promoter were not associated with VWF:Ag levels at baseline nor with the VWF:Ag increase. Conclusions: VWF:Ag levels strongly increase upon exhaustive exercise and this increase is strongly determined by physical fitness level and the intensity of the exercise, while there is no clear effect of genetic variation in STXBP5, STX2 and the VWF promoter
Widespread occurrence of an emerging fungal pathogen in heavily traded Chinese urodelan species
Understanding introduction routes for wildlife pathogens is vital for the development of threat abatement plans. The chytrid fungus Batrachochytrium salamandrivorans (Bsal) has recently emerged in Europe, where it is considered to be a serious threat for urodelan conservation. If the highly diverse Chinese urodelans were to constitute a Bsal reservoir, then the significant international trade in these species may vector Bsal into naïve urodelan communities. Here, we analyzed a total of 1,143 samples, representing 36 Chinese salamander species from 51 localities across southern China for the presence of Bsal. We found Bsal was present across a wide taxonomic, geographical, and environmental range. In particular, Bsal DNA was detected in 33 samples from the genera Cynops, Pachytriton, Paramesotriton, Tylototriton, and Andrias, including the heavily traded species Paramesotriton hongkongensis and Cynops orientalis. The true Bsal prevalence across our data set was estimated between 2% and 4%, with a maximum of 50% in a population of P. hongkongensis. Even at this overall relatively low Bsal prevalence, the exportation of millions of animals renders Bsal introduction in naïve, importing countries a near certainty, which calls for the urgent implementation of proper biosecurity in the international wildlife trade
Evolution of antimicrobial resistance of Salmonella isolates from pigs in Belgium
The aim of the present study was to investigate the antimicrobial sensitivity of Salmonella isolates from pigs between 2011 and 2015. In total, 275 Salmonella isolates from samples originating from pigs sent in for diagnostic examination at Animal Health Care Flanders were tested for their sensitivity against different antimicrobials. Except for colistin, where the disk prediffusion test was used, the disk diffusion test was used. E. coli ATCC 25922 was used as reference isolate and the interpretative breakpoints were based on the Clinical and Laboratory Standards Institute
Local strain variation in the plies of a satin weave composite: experimental vs. numerical
Along with the advantages of multi directional load carrying capabilities, the complicated interlacing pattern of the yarns in a textile composite produce large stress – strain gradients. The stress-strain behavior in a textile composite is influenced by: a) stacking sequence; b) number of plies in the laminate; c) distance of the ply to the surface [1]. From the numerical perspective, the investigation of the free edge and free surface effects in a textile composite unit cell [2] reveals that the local stress behavior changes considerably depending upon the finite/ infinite conditions used for the unit cell FE analysis. In the above context, to capture the variation in local parameters such as strain and damage profiles at different locations (inside/surface) of the satin weave composite under the tensile load, experimental techniques such as strain mapping, Fibre Brag Grating sensors (FBG’s) and the microscopic analysis is used. For the numerical validation, different unit cell stacking models with appropriate boundary conditions are used for the FE analysis. Comparison of the numerical and experimental results (Table 1) provides valuable information regarding the local strain variation (from edge to the centre) in a satin weave composite (Figure 1). In the similar guide lines, local damage variation is also studied using different unit cell stacks
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