108 research outputs found
Infection of neonatal mice with the murine norovirus strain WU23 is a robust model to study norovirus pathogenesis
Noroviruses are the leading cause of severe childhood diarrhea and foodborne disease worldwide. While they are a major cause of disease in all age groups, infections in the very young can be quite severe, with annual estimates of 50,000-200,000 fatalities in children under 5 years old. In spite of the remarkable disease burden associated with norovirus infections, very little is known about the pathogenic mechanisms underlying norovirus diarrhea, principally because of the lack of tractable small animal models. The development of the murine norovirus (MNV) model nearly two decades ago has facilitated progress in understanding host-norovirus interactions and norovirus strain variability. However, MNV strains tested thus far either do not cause intestinal disease or were isolated from extraintestinal tissue, raising concerns about translatability of research findings to human norovirus disease. Consequently, the field lacks a strong model of norovirus gastroenteritis. Here we provide a comprehensive characterization of a new small animal model system for the norovirus field that overcomes prior weaknesses. Specifically, we demonstrate that the WU23 MNV strain isolated from a mouse naturally presenting with diarrhea causes a transient reduction in weight gain and acute self-resolving diarrhea in neonatal mice of several inbred mouse lines. Moreover, our findings reveal that norovirus-induced diarrhea is associated with infection of subepithelial cells in the small intestine and systemic spread. Finally, type I interferons (IFNs) are critical to protect hosts from norovirus-induced intestinal disease whereas type III IFNs exacerbate diarrhea. This latter finding is consistent with other emerging data implicating type III IFNs in the exacerbation of some viral diseases. This new model system should enable a detailed investigation of norovirus disease mechanisms
Group polarization effect on decisions by selected Kenyan secondary school disciplinary panels
This study investigated social group phenomenon of group polarization effects on disciplinary hearing decisions in
selected Kenyan secondary school. The participants were 78 school personnel (females = 42%and males 58%) from ten
secondary schools with both unisex (n = 39) and co-educational schools (n = 39). Both quantitative and qualitative data
were collected and analyzed. The results suggested group polarization effects in disciplinary hearing decisions, in that
there were shifts from pre to post-disciplinary hearing decisions. Persuasive arguments and social comparisons
significantly influenced group polarization decisions.Department of HE and Training approved lis
Characterization and Whole Genome Analysis of Human Papillomavirus Type 16 E1-1374^63nt Variants
Background. The variation of the most common Human papillomavirus (HPV) type found in cervical cancer, the HPV16, has been extensively investigated in almost all viral genes. The E1 gene variation, however, has been rarely studied. The main objective of the present investigation was to analyze the variability of the E6 and E1 genes, focusing on the recently identified E1-1374^63nt variant. Methodology/Principal Findings. Variation within the E6 of 786 HPV16 positive cervical samples was analyzed using high-resolution melting, while the E1-1374^63nt duplication was assayed by PCR. Both techniques were supplemented with sequencing. The E1-1374^63nt duplication was linked with the E-G350 and the E-C109/G350 variants. In comparison to the referent HPV16, the E1-1374^63nt E-G350 variant was significantly associated with lower grade cervical lesions (p=0.029), while the E1-1374^63nt E-C109/G350 variant was equally distributed between high and low grade lesions. The E1-1374^63nt variants were phylogenetically closest to E-G350 variant lineage (A2 sub-lineage based on full genome classification). The major differences between E1-1374^63nt variants were within the LCR and the E6 region. On the other hand, changes within the E1 region were the major differences from the A2 sub-lineage, which has been historically but inconclusively associated with high grade cervical disease. Thus, the shared variations cannot explain the particular association of the E1-1374^63nt variant with lower grade cervical lesions. Conclusions/Significance. The E1 region has been thus far considered to be well conserved among all HPVs and therefore uninteresting for variability studies. However, this study shows that the variations within the E1 region could possibly affect cervical disease, since the E1-1374^63nt E-G350 variant is significantly associated with lower grade cervical lesions, in comparison to the A1 and A2 sub-lineage variants. Furthermore, it appears that the silent variation 109T>C of the E-C109/G350 variant might have a significant role in the viral life cycle and warrants further study
Functional variants of human papillomavirus type 16 demonstrate host genome integration and transcriptional alterations corresponding to their unique cancer epidemiology
Impacts of soil conditions and light availability on natural regeneration of Norway spruce Picea abies (L.) H. Karst. in low-elevation mountain forests
& Key message Natural regeneration of P. abies (L.) H. Karst. may reach high densities in lower mountain elevations. The
highest densities were found in sites with moderate light availability, with low pH, and not near the riverbank. However,
age-height classes differed in the predicted magnitude of response, but were consistent in response directions. Mosses and
understory species typical of coniferous forests were positively correlated with regeneration density.
& Context Norway spruce Picea abies (L.) H. Karst. in Central Europe is at risk under climate change scenarios, particularly in
mountain regions. Little is known about the impact of environmental factors on the natural regeneration of P. abies in lowelevation mountain forests.
& Aims We aimed to assess impacts of distance from the riverbank, soil pH, and light availability on natural P. abies regeneration.
We hypothesized that (1) natural P. abiesregeneration would depend on light availability and soil pH and (2) there are understory
plant species which may indicate the microsites suitable for natural regeneration of P. abies.
& Methods The study was conducted in the Stołowe Mountains National Park (SW Poland, 600–800 m a.s.l.). We established 160
study plots (25 m2
) for natural regeneration, light availability, soil pH, and understory vegetation assessment
Influences de la sylviculture sur le risque de dégâts biotiques et abiotiques dans les peuplements forestiers
Xylosandrus germanus (Bldf.) (Coleoptera: Curculionidae, Scolytinae) in Poland
The information about the occurrence of the invasive bark beetle Xylosandrus germanus (Bldf.) in Poland is presented. A set of traits enabling its distinguishing from similar Anisandrus dispar is provided
Digits recognition using an educational robot
Artykuł przedstawia system rozpoznający liczby rzymskie przy użyciu edukacyjnego zestawu Mindstorms NXT. Algorytm OCR wybrany do rozpoznania znaków został oparty na klasyfikacji cech. Zaadaptowana wersja algorytmu Region of Interest ROI i klasyfikacja cech są głównymi atutami tej pracy. System został skutecznie przetestowany pod wieloma względami. Powstała konstrukcja umożliwiająca skanowanie kartki formatu A4, a obsługujący ją program umożliwia prawidłową interpretację zeskanowanych liczb rzymskich.Pattern recognition is always associated with powerful calculation [1, 2]. A specific branch in this area is Optical Character Recognition [3, 4, 5] where one of the most popular techniques is Feature Extraction, also known as Intelligent Character Recognition [6]. All ICR algorithms are topological [7, 8, 9]. This paper presents an implementation of Roman Number Recognition system realized on LEGO Mindstorms NXT educational robot. The main point is successful minimalistic realization of an on-board pattern recognition system. The NXT platform allows also an easy reconfiguration of the hardware and more building freedom without extra costs (Fig. 1.). An adapted version of the ROI algorithm is implemented [10]. Based on the extracted features (Fig. 2.) a classification of the roman digits is proposed (Fig. 3.). The final stage of the program includes segmentation, end result calculation and visualization of it on the robot screen. The conducted experimental tests proved a 100% efficiency for digit and number recognition having a process in optimal conditions and quite good stability for the optical noises (Fig. 4.) and color chances (Tab. 1). In spite of many drawbacks of the hardware, the implemented system seems very perspective and invokes many ideas toward pattern recognition technics
Skutecznosc wystawiania pulapek feromonowych na kornika drukarza Ips typographus [L.] w sasiedztwie wiatrowalow i wiatrolomow
- …