104 research outputs found
Resolving flow and mass transport in a healthy subject-specific aorta using large eddy simulation
Den extraarbetande studenten
Studenters ekonomi är ofta i fokus, både i media och i folkmun. Det talas ofta höjt studiestöd men också om studenternas vanor kring extraarbete. En del anklagar dem för att vara ovilliga att arbeta extra medan andra påpekar det faktum att en heltidsstudent förväntas lägga ner 40 timmar i veckan på sina studier. Syftet med föreliggande studie var att applicera Theory of Planned Behavior för att undersöka de psykologiska faktorernas inverkan på graden av extraarbete med hjälp av en enkätundersökning. Resultaten tolkades med en multipel regressionsanalys och olika oberoende variansanalyser. Studien visade att ”Attityd mot beteendet” och ”Upplevd beteendekontroll” var de psykologiska faktorer som bäst samvarierade med graden av extraarbete. Studien visade även att studenternas ålder inte var avgörande för hur mycket studenterna valde att arbeta extra. Samtliga studenter (N=50) som deltog i undersökningen var vid genomförandet heltidsstudenter samt arbetade extra minst en gång per vecka
Acceptable noise level: Repeatability with Danish and non-semantic speech materials for adults with normal hearing
Objective: The acceptable noise level (ANL) is used to quantify the amount of background noise that subjects can accept while listening to speech, and is suggested for prediction of individual hearing-aid use. The aim of this study was to assess the repeatability of the ANL measured in normal-hearing subjects using running Danish and non-semantic speech materials as stimuli and modulated speech-spectrum and multi-talker babble noises as competing stimuli. Design: ANL was measured in both ears at two test sessions separated by a period ranging from 12 to 77 days. At each session the measurements at the first and the second ear were separated in time by 15-30 minutes. Bland-Altman plots and calculation of the coefficient of repeatability (CR) were used to estimate the repeatability. Study sample: Thirty nine normal-hearing subjects. Results: The ANL CR was 6.0-8.9 dB for repeated tests separated by about 15-30 minutes and 7.2-10.2 dB for repeated tests separated by 12 days or more. Conclusions: The ANL test has poor repeatability when assessed with Danish and non-semantic speech materials on normal-hearing subjects. The same CR among hearing-impaired subjects would imply too poor repeatability to predict individual patterns of future hearing-aid use
Acceptable noise level with Danish, Swedish, and non-semantic speech materials.
Objective: Acceptable noise level (ANL) has been established as a method to quantify the acceptance of background noise while listening to speech presented at the most comfortable level. The aim of the present study was to generate Danish, Swedish, and a non-semantic version of the ANL test and investigate normal-hearing Danish and Swedish subjects' performance on these tests. Design: ANL was measured using Danish and Swedish running speech with two different noises: Speech-weighted amplitude-modulated noise, and multitalker speech babble. ANL was also measured using the non-semantic international speech test signal (ISTS) as speech signal together with the speech-weighted amplitude-modulated noise. The latter condition was identical in both populations. Study sample: Forty Danish and 40 Swedish normal-hearing subjects. Results: In both populations ANL results were similar to previously reported results from American studies. Generally, significant differences were seen between test conditions using different types of noise within ears in each population. Significant differences were seen for ANL across populations, also when the non-semantic ISTS was used as speech signal. Conclusions: The present findings indicate that there are extrinsic factors, such as instructions, affecting the ANL results. Summario Objetivo: Se ha establecido el Nivel de Ruido Aceptable (ANL) como un método para cuantifi car la aceptación de ruido de fondo mientras se escucha lenguaje presentado al nivel más confortable. El objetivo de este estudio fue generar las versiones sueca, danesa y una no-semántica de la prueba ANL e investigar el desempeño de sujetos normoyentes daneses y suecos en estas pruebas. Diseño: Se midió el ANL utilizando un discurso continuo en danés y sueco con dos diferentes ruidos: ruido con amplitud modulada en el rango del lenguaje y balbuceo de varios hablantes. También se midió el ANL utilizando la prueba internacional no-semántica de señal de lenguaje (ISTS) como la señal lingüística junto con ruido con amplitud modulada en el rango del lenguaje. Esta última condición fue idéntica en ambas poblaciones. Muestra: Cuarenta sujetos daneses y 40 sujetos suecos normoyentes. Resultados: en ambas poblaciones los resultados de ANL fueron muy similares a los reportado previamente en estudios americanos. Generalmente, se vieron diferencias signifi cativas para el ANL entre poblaciones, también cuando el ISTS no semántico fue utilizado como señal lingüística. Conclusiones: Estos hallazgos indican que hay factores extrínsecos tales como las instrucciones, que afectan los resultados de ANL
О русских и английских фразеологизмах, заимствованных из литературных источников
Материалы XII Междунар. науч. конф. студентов, магистрантов, аспирантов и молодых ученых, Гомель, 16–17 мая 2019 г
Methodic Approach to the Evaluation of the Efficiency of Integration of Industrial Enterprises in the Republic of Belarus
Представлен авторский методический подход к ретроспективной оценке эффективности интеграции промышленных предприятий в Республике Беларусь, учитывающий особенности ведения хозяйственной деятельности в современных условиях национальной экономики, и результаты его апробации на материалах холдинга «Гомсельмаш». Разработанный методический подход включает алгоритм ретроспективной оценки эффективности, определяющий последовательность действий по анализу и оценке результатов интеграции, методику оценки эффективности интеграции промышленных предприятий, в основу которой положен принцип детерминированности показателей оценки эффективности иерархической последовательностью их взаимосвязи с критериями эффективности интеграции и целями интеграции, методический инструментарий анализа и оценки эффективности результатов интеграции промышленных предприятий, включающий набор расчетных формул частных, обобщающих и интегрального показателей эффективности интеграции; критерии оценки эффективности и целесообразности интеграции, определяемые степенью достижения поставленных целей интеграции; рекомен-дации по применению разработанной методики.The author’s methodic approach to the retrospective evaluation of the efficiency of integration of industrial enterprises in the Republic of Belarus is presented in the paper, taking into account specific features of providing economic activity in the present-day conditions of national economy and also the results of its testing based on the data of Gomselmash Holding. Methodic approach developed includes the algorithm of retrospective efficiency evaluation determining the sequence of operations for the analysis and evaluation of integration results, the methods of evaluation of industrial enterprise integration efficiency, based on the principle of determinacy of the indices of the efficiency evaluation by hierarchical sequence of their interrelation with the criteria of integration efficiency and the objectives of integration, methodic tools for the analysis and evaluation of the results of industrial enterprise integration including a set of design formulas of partial, overall and integral indices of the efficiency of integration; the criteria of evaluation of the efficiency and practicability of integration determined by the formulated integration goals achievement; the guidelines on the application of the methods developed
Publisher Correction: Bridging the gap between measurements and modelling: a cardiovascular functional avatar.
An amendment to this paper has been published and can be accessed via a link at the top of the paper
Elevated atrial blood stasis in paroxysmal atrial fibrillation during sinus rhythm: a patient-specific computational fluid dynamics study
IntroductionAtrial fibrillation (AF) is associated with an increased risk of stroke, often caused by thrombi that form in the left atrium (LA), and especially in the left atrial appendage (LAA). The underlying mechanism is not fully understood but is thought to be related to stagnant blood flow, which might be present despite sinus rhythm. However, measuring blood flow and stasis in the LAA is challenging due to its small size and low velocities. We aimed to compare the blood flow and stasis in the left atrium of paroxysmal AF patients with controls using computational fluid dynamics (CFD) simulations.MethodsThe CFD simulations were based on time-resolved computed tomography including the patient-specific cardiac motion. The pipeline allowed for analysis of 21 patients with paroxysmal AF and 8 controls. Stasis was estimated by computing the blood residence time.Results and DiscussionResidence time was elevated in the AF group (p < 0.001). Linear regression analysis revealed that stasis was strongest associated with LA ejection ratio (p < 0.001, R2 = 0.68) and the ratio of LA volume and left ventricular stroke volume (p < 0.001, R2 = 0.81). Stroke risk due to LA thrombi could already be elevated in AF patients during sinus rhythm. In the future, patient specific CFD simulations may add to the assessment of this risk and support diagnosis and treatment
Quantifying turbulent wall shear stress in a subject specific human aorta using large eddy simulation
Innate Immune Function in Placenta and Cord Blood of Hepatitis C – Seropositive Mother-Infant Dyads
Vertical transmission accounts for the majority of pediatric cases of hepatitis C viral (HCV) infection. In contrast to the adult population who develop persistent viremia in ∼80% of cases following exposure, the rate of mother-to-child transmission (2–6%) is strikingly low. Protection from vertical transmission likely requires the coordination of multiple components of the immune system. Placenta and decidua provide a direct connection between mother and infant. We hypothesized that innate immune responses would differ across the three compartments (decidua, placenta and cord blood) and that hepatitis C exposure would modify innate immunity in these tissues. The study was comprised of HCV-infected and healthy control mother and infant pairs from whom cord blood, placenta and decidua were collected with isolation of mononuclear cells. Multiparameter flow cytometry was performed to assess the phenotype, intracellular cytokine production and cytotoxicity of the cells. In keeping with a model where the maternal-fetal interface provides antiviral protection, we found a gradient in proportional frequencies of NKT and γδ-T cells being higher in placenta than cord blood. Cytotoxicity of NK and NKT cells was enhanced in placenta and placental NKT cytotoxicity was further increased by HCV infection. HCV exposure had multiple effects on innate cells including a decrease in activation markers (CD69, TRAIL and NKp44) on NK cells and a decrease in plasmacytoid dendritic cells in both placenta and cord blood of exposed infants. In summary, the placenta represents an active innate immunological organ that provides antiviral protection against HCV transmission in the majority of cases; the increased incidence in preterm labor previously described in HCV-seropositive mothers may be related to enhanced cytotoxicity of NKT cells
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