Search results for " model"
showing 10 items of 16868 documents
Vaginal infection of mice with HSV type 2 variant ER−: A new animal model for human primary genital HSV type 2 infections
1992
Abstract Studying the pathogenesis of vaginal infections in mice with two variants of Herpes simplex virus type 2 (HSV-2) strain ER we observed that both variants ER+ and ER− caused severe vaginitis but only ER+ invaded the CNS leading to lethal neurological disease. In contrast, mice infected with ER− cleared the virus from the vagina and recovered from infection. ER+ and ER− expressed equal levels of thymidine kinase (TK) indicating a TK-independent difference in neurovirulence. Using the non-neurovirulent variant ER−, we were able to investigate humoral immune responses late after infection. Vaginal infection with ER− suppressed serum antibody formation after a secondary systemic HSV-1 i…
Mouse models of cytomegalovirus latency: overview.
2002
Abstract Background: The molecular regulation of viral latency and reactivation is a central unsolved issue in the understanding of cytomegalovirus (CMV) biology. Like human CMV (hCMV), murine CMV (mCMV) can establish a latent infection in cells of the myeloid lineage. Since mCMV genome remains present in various organs after its clearance from hematopoietic cells first in bone marrow and much later in blood, there must exist one or more widely distributed cell type(s) representing the cellular site(s) of enduring mCMV latency in host tissues. Endothelial cells and histiocytes are candidates, but the question is not yet settled. Another long debated problem appears to be solved: mCMV establ…
OCTA atlīdzību apjoma modelēšana, lietojot vispārināto lineāro modeli
2017
Darbs veltīts obligātās civiltiesiskās transportlīdzekļu apdrošināšanas (OCTA) atlīdzību modelēšanai. Modeļu klase, ko izvēlēts lietot, ir vispārinātais lineārais modelis (GLM), kas praksē tiek bieži lietots apdrošināšanas atlīdzību modelēšanai. Darbā aprakstīti vispārinātā lineārā modeļa teorijas pamati un modeļa precizitātes novērtēšanas mēri. Aplūkotas dažādas modeļa parametru novērtēšanas un faktoru atlases metodes, no iegūtajiem modeļiem izvēlēts modelis ar labāko pielāgošanas kvalitāti un precīzāko prognozēšanas spēju. Visbiežāk lietotās metodes - iteratīvā mazāko kvadrātu metode parametru novērtēšanai un soļu regresija faktoru atlasei tika salīdzinātas ar lasso un elastīgo tīklu regu…
Vispārināto lineāro un vispārināto aditīvo modeļu salīdzinājums un pielietojumi
2019
Šajā darbā aprakstītas divas matemātiskās modelēšanas metodes, tās ir, vispārinātais lineārais modelis (generalized linear model (GLM)) un vispārinātais aditīvais modelis (generalized additive model (GAM)), un metodes, ar kurām tie ir saistīti. Darbā ir aprakstītas novērtēšanas metodes un kritēriji, kas tiek izmantoti šādu modeļu analizēšanai un novērtēšanai. Šī darba praktiskā daļa ir veikta programmā R, kur ir salīdzināti vispārinātais lineārais un vispārinātais aditīvais modelis ar mērķi izprast modeļu atšķirības un atšķirt gadījumus, kad labāk izvēlēties vienu vai otru modelēšanas metodi. Veicot darba praktisko daļu, tiek secināts, ka datiem, kuru izkliede nav vienkārša atkarībā no skai…
Vai strukturālās reformas spēs veicināt Latvijas ekonomisko izaugsmi: BMA un GMM novērtējumu liecības
2017
Pētījuma ietvaros tiek pielietota Beijesa modeļu svēršana (BMA) un vispārīgā momentu metode (GMM) Globālās Konkurētspējas apakšindeksu (GCI) datiem, lai identificētu strukturālo reformu jomas, kas var nozīmīgi paātrināt Latvijas ekonomisko izaugsmi. Novērtējumu rezultāti, kuros ņemta vērā gan modeļu nenoteiktība, gan endogenitāte liecina, ka ekonomisko izaugsmi var veicināt ar augstākām investīcijām, zemāku administratīvo slogu, stabilāku makroekonomisko vidi, paaugstinātu ārvalsts tiešo investīciju kvalitāti, kā arī ar attīstītākiem uzņēmējdarbības klasteriem. Ja šajās jomās Latvijas sniegums pēdējo 10 gadu laikā būtu trīs labāko Eiropas Savienības dalībvalstu līmenī, tad ienākumu līmenis …
Impacts of Touch Screen Size, User Interface Design, and Subtask Boundaries on In-Car Task's Visual Demand and Driver Distraction
2020
Visual distraction by secondary in-car tasks is a major contributing factor in traffic incidents. In-car user interface design may mitigate these negative effects but to accomplish this, design factors’ visual distraction potential should be better understood. The effects of touch screen size, user interface design, and subtask boundaries on in-car task's visual demand and visual distraction potential were studied in two driving simulator experiments with 48 participants. Multilevel modeling was utilized to control the visual demands of driving and individual differences on in-car glance durations. The 2.5” larger touch screen slightly decreased the in-car glance durations and had a diminis…
Negative emotional state modulates visual working memory in the late consolidation phase
2020
Although a considerable literature has grown up around the interactions between emotional state and visual working memory (VWM) performance, the mechanism underlying the impact of the negative emotional state on VWM remains unclear. The present study aimed to test whether the influence of emotional state is related to the early phase or late phase of VWM consolidation process. Across three experiments, we found that the negative emotional state did not affect VWM performance when the presentation time of stimuli was short. However, when the presentation time was long, the negative emotional state increased the VWM precision and reduced the VWM number. According to the two-phase model propos…
Study of vocalists' use of emotions in performance preparation
2015
Musicians and educators understand the importance of expressivity in vocal performance. Despite the acceptance of expressivity as a crucial element in musical performance, educators have reported addressing it only cursorily or not addressing it at all when preparing for a performance. For these reasons, this research has focused on techniques used by trained musicians when preparing a performance, to be adapted and applied for use by teachers with their large vocal ensembles. Participants in this study were enrolled in vocal / operatic performance programs at universities in the United States, Ireland, Finland, and Hong Kong. Their progress was tracked throughout the semester by three ques…
MODELING OF VOLATILITY IN THE ROMANIAN CAPITAL MARKET
2012
This paper aims to analyze the volatility of capital market in Romania by selecting a portfolio of representative indices (BET BET_FI and RASDAQ_C). In this respect, we want to identify the most appropriate model to estimate volatility by using modern econometric tools and useful GARCH models respectively. The study results highlight that EGARCH(1,1) model has managed to eliminate all traces of statistically significant autocorrelation and ARCH effects from the residuals from daily series, giving an accurate image of the Romanian capital market volatility.
Ultraviolet imaging of volcanic plumes: A new paradigm in volcanology
2017
Ultraviolet imaging has been applied in volcanology over the last ten years or so. This provides considerably higher temporal and spatial resolution volcanic gas emission rate data than available previously, enabling the volcanology community to investigate a range of far faster plume degassing processes than achievable hitherto. To date, this has covered rapid oscillations in passive degassing through conduits and lava lakes, as well as puffing and explosions, facilitating exciting connections to be made for the first time between previously rather separate sub-disciplines of volcanology. Firstly, there has been corroboration between geophysical and degassing datasets at â1 Hz, expeditin…