661 research outputs found
Exploring the impact of external shading system on cognitive task performance, alertness and visual comfort in a daylit workplace environment
The authors examined the effect of external shading system on cognitive performance, alertness and visual comfort of visual display terminal (VDT) users under two realistic office lighting settings in this study. Daylight was the source of illumination being considered as the most significant and preferred one. A total of 26 participants performed visual and cognitive demanding tasks as well as providing subjective alertness, performance and visual evaluations in a full-scale mock-up VDT workstation. Two trials (with and without shading system) were executed during one experimental session. Results revealed that the use of a shading system improves the performance of a user on colour-naming task requiring sustained attention, while no differential effects were observed on tasks involving other cognitive skills such as search velocity and vigilance. Within-subject performance differences were more pronounced during morning hours. Higher performance was reported in some cognitive tests when the subjective sensation of visual discomfort was lower
Determination of natural radioactivity levels in soil and travertine of the region of Tokat and Sivas, Turkey
WOS: 000429070100015In this study, the environmental radioactivity measurements for Tokat and Sivas provinces in the northeast of Turkey were performed. Using gamma ray spectrometry, the activity concentrations of natural radionuclides in soil and travertine samples (Th-232, Ra-226, and K-40) were determined. The annual effective dose equivalent, the absorbed doses rate in air, the radium equivalent, and the external hazard index were obtained from these activities. The activity concentrations vary from 9.09 to 17.04 Bq kg(-1) for Th-232, from 36.53 to 76.95 Bq kg(-1) for Ra-226, and from 216.56 to 576.59 Bq kg(-1) for K-40 in soil samples. The activity concentrations in travertines vary from 15.99 to 21.01 Bq kg(-1) for Th-232, from 19.89 to 67.71 Bq kg(-1) for Ra-226, and from 179.89 to 314.43 Bq kg(-1) for K-40. The average dose rate in air for soil and travertine samples was 43.41 and 41.05 nGy h(-1) respectively. The obtained results are presented and compared with other studies, and the results of this study are lower than the international recommended value (55 nGy h(-1)) given by UNSCEAR (2000). The results show that the region has a background radiation level within the natural limits.Gaziosmanpasa University Scientific Research Projects Department (BAP)Gaziosmanpasa University [24/2013]This work is supported by Gaziosmanpasa University Scientific Research Projects Department (BAP) under project no. 24/2013
Classification of forest and shrubland vegetation in Mediterranean Turkey
Questions What are the main vegetation types of forest and shrubland vegetation at the alliance level in Mediterranean Turkey? What is their syntaxonomical position? Can we integrate them into the European vegetation classification system? Which environmental factors are the main drivers of the floristic differentiation of vegetation types? Location Southern and western Turkey. Methods We collected 4,717 vegetation plots of forest and shrubland vegetation in Mediterranean Turkey and performed an unsupervised classification of this data set. We described vegetation types based on the classification results, expert knowledge and information from the literature. We defined diagnostic species and prepared distribution maps for each vegetation type. To support the interpretation of the vegetation types, we determined the most important environmental variables using canonical correspondence analysis. Results The studied vegetation was divided into 21 types related to three vegetation belts: (a) thermo- and meso-mediterranean, comprising coniferous (Pinus brutia, Pinus pinea) and sclerophyllous forests, as well as macchia, garrigue and phrygana; (b) supra-mediterranean, comprising Pinus nigra subsp. pallasiana forests, thermophilous deciduous forests dominated by various oak species and Ostrya carpinifolia, and forests dominated by temperate species such as Fagus orientalis; and (c) oro-mediterranean, comprising forests and shrublands dominated by Abies cilicica, Cedrus libani, Juniperus excelsa and Juniperus communis subsp. nana. Elevation was identified as the main environmental driver of the vegetation pattern. Among climatic variables, the most important are the mean temperatures (annual and of driest, coldest, and warmest quarters), minimum temperature of winter, precipitation of warmest and driest quarters and precipitation seasonality. These factors indicate the decreasing effect of the Mediterranean climate with increasing elevation. Conclusions The vegetation of Mediterranean Turkey is arranged along climatic gradients depending on elevation and the distance from the Mediterranean Sea. Most vegetation types in this area correspond to the syntaxa accepted in EuroVegChecklist, while others were described as new
Promoting Connectivity of Network-Like Structures by Enforcing Region Separation
We propose a novel, connectivity-oriented loss function for training deep
convolutional networks to reconstruct network-like structures, like roads and
irrigation canals, from aerial images. The main idea behind our loss is to
express the connectivity of roads, or canals, in terms of disconnections that
they create between background regions of the image. In simple terms, a gap in
the predicted road causes two background regions, that lie on the opposite
sides of a ground truth road, to touch in prediction. Our loss function is
designed to prevent such unwanted connections between background regions, and
therefore close the gaps in predicted roads. It also prevents predicting false
positive roads and canals by penalizing unwarranted disconnections of
background regions. In order to capture even short, dead-ending road segments,
we evaluate the loss in small image crops. We show, in experiments on two
standard road benchmarks and a new data set of irrigation canals, that convnets
trained with our loss function recover road connectivity so well, that it
suffices to skeletonize their output to produce state of the art maps. A
distinct advantage of our approach is that the loss can be plugged in to any
existing training setup without further modifications
Spin glass behavior in FeAl2
Journals published by the American Physical Society can be found at http://journals.aps.org/Magnetic and transport measurements indicate FeAl2 to be an ordered intermetallic spin glass, with canonical behavior including a susceptibility cusp at T-f = 35 K and frequency-dependent susceptibility below T-f. The field-cooled and zero-held-cooled magnetization diverge below T-f, with hysteresis characteristic of a spin glass. A resistivity minimum just above T-f is explained in terms of coherent magnetic scattering. This behavior is common to spin glasses with short-range interactions among f-electron moments and indicates a similar spin configuration in these materials
A critical analysis of COVID-19 research literature: Text mining approach
Objective: Among the stakeholders of COVID-19 research, clinicians particularly experience difficulty keeping up with the deluge of SARS-CoV-2 literature while performing their much needed clinical duties. By revealing major topics, this study proposes a text-mining approach as an alternative to navigating large volumes of COVID-19 literature. Materials and methods: We obtained 85,268 references from the NIH COVID-19 Portfolio as of November 21. After the exclusion based on inadequate abstracts, 65,262 articles remained in the final corpus. We utilized natural language processing to curate and generate the term list. We applied topic modeling analyses and multiple correspondence analyses to reveal the major topics and the associations among topics, journal countries, and publication sources. Results: In our text mining analyses of NIHâs COVID-19 Portfolio, we discovered two sets of eleven major research topics by analyzing abstracts and titles of the articles separately. The eleven major areas of COVID-19 research based on abstracts included the following topics: 1) Public Health, 2) Patient Care & Outcomes, 3) Epidemiologic Modeling, 4) Diagnosis and Complications, 5) Mechanism of Disease, 6) Health System Response, 7) Pandemic Control, 8) Protection/Prevention, 9) Mental/Behavioral Health, 10) Detection/Testing, 11) Treatment Options. Further analyses revealed that five (2,3,4,5, and 9) of the eleven abstract-based topics showed a significant correlation (ranked from moderate to weak) with title-based topics. Conclusion: By offering up the more dynamic, scalable, and responsive categorization of published literature, our study provides valuable insights to the stakeholders of COVID-19 research, particularly clinicians.3417985
3D segmentation of intervertebral discs: from concept to the fabrication of patient-specific scaffolds
Aim: To develop a methodology for producing patient-specific scaffolds that mimic the annulus fibrosus (AF) of the human intervertebral disc (IVD) by means of combining magnetic resonance imaging (MRI) and 3D bioprinting. Methods: In order to obtain the AF 3D model from patientĂą s volumetric MRI dataset, the RheumaSCORE segmentation software was used. Polycaprolactone scaffolds with three different internal architectures were fabricated by 3D bioprinting, and characterized by micro-computed tomography.
Results: The demonstrated methodology of a geometry reconstruction pipeline enabled to successfully obtain an accurate AF model and 3D print patient-specific scaffolds with different internal architectures.
Conclusion: The results guide us towards patient-specific IVD tissue engineering as demonstrated a way of manufacturing personalized scaffolds using patient's MRI data.The authors would like to acknowledge the financial support provided by the Portuguese Foundation for Science and Technology (FCT) through the project EPIDisc (UTAPEXPL/BBB-ECT/0050/2014),
funded in the Framework of the âInternational Collaboratory for Emerging Technologies, CoLabâ, UT
justin|Portugal Program. FCT is also acknowledged for the PhD scholarship attributed to IF Cengiz (SFRH/
BD/99555/2014) and the financial support provided to J Silva-Correia (SFRH/BPD/100590/2014 and IF/00115/2015).
JM Oliveira also thanks the FCT for the funds provided under the program Investigador FCT (IF/00423/2012 and IF/01285/2015). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.
No writing assistance was utilized in the production of this manuscript.info:eu-repo/semantics/publishedVersio
Conducting a European multi-center trial: first experiences with the new EU Clinical Trials Directive from an academic perspective
Strength development characteristics of concrete produced with blended cement using Ground Granulated Blast furnace Slag (GGBS) under various curing conditions
Surgical Decision Making for Unstable Thoracolumbar Spine Injuries: Results of a Consensus Panel Review by the Spine Trauma Study Group
Objectives: The optimal surgical approach and treatment of unstable thoracolumbar spine injuries are poorly defined owing to a lack of widely accepted level I clinical literature. This lack of evidence based standards has led to varied practice patterns based on individual surgeon preferences. The purpose of this study was to survey the leaders in the field of spine trauma to define the major characteristics of thoracolumbar injuries that influence their surgical decision making. In the absence of good scientific data, expert consensus opinions may provide surgeons with a practical framework to guide therapy and to conduct future research.
Methods: A panel of 22 leading spinal surgeons from 20 level I trauma centers in seven countries met to discuss the indications for surgical approach selection in unstable thoracolumbar injuries. Injuries were presented to the surgeons in a case scenario survey format. Preferred surgical approaches to the clinical scenarios were tabulated and comments weighed. Results: All members of the panel agreed that three independent characteristics of thoracolumbar injuries carry primary importance in surgical decision making: the injury morphology, the neurologic status of the patient, and the integrity of the posterior ligaments. Six clinical scenarios based on the neurologic status of the patient (intact, incomplete, or complete) and on the status of the posterior ligamentous complex (intact or disrupted) were created, and consensus treatment approaches were described. Additional circumstances capable of altering the treatments were acknowledged.
Conclusions: Decision making for the surgical treatment of thoracolumbar injuries is largely dependent on three patient characteristics: injury morphology, neurologic status, and posterior ligament integrity. A logical and practical decision-making process based on these characteristics may guide treatment even for the most complicated fracture patterns
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