Search results for "Laboratory"
showing 10 items of 923 documents
Host-range expansion of Spodoptera exigua multiple nucleopolyhedrovirus to Agrotis segetum larvae when the midgut is bypassed.
2010
Given the high similarity in genome content and organization between Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV) and Agrotis segetum nucleopolyhedrovirus (AgseNPV), as well as the high percentages of similarity found between their 30 core genes, the specificity of these NPVs was analysed for the respective insect hosts, S. exigua and A. segetum. The LD(50) for AgseNPV in second-instar A. segetum larvae was 83 occlusion bodies per larva and the LT(50) was 8.1 days. AgseNPV was orally infectious for S. exigua, but the LD(50) was 10 000-fold higher than for SeMNPV. SeMNPV was not infectious for A. segetum larvae when administered orally, but an infection was established by injecti…
Use of bitumen-stabilised ballast for improving railway trackbed conventional maintenance
2018
Despite its many advantages, ballasted track needs frequent maintenance to ensure an adequate quality of service. However, tamping, traditionally used to correct geometry, causes ballast degradation and loosening of the already compacted ballast layer, which quickly returns the track to its pre-maintenance position. Then, other maintenance techniques such as stoneblowing, as well as diverse solutions that reinforce trackbed, have been developed to reduce ballast settlement and particles degradation. Given the need to further advance research in this field, bitumen-stabilised ballast (BSB) has started to be investigated by the authors as a feasible solution thanks to its easy and quick appl…
Experimental observations of upstream overdeepening
2005
The issue of morphodynamic influence in meandering streams is investigated through a series of laboratory experiments on curved and straight flumes. Both qualitative and quantitative observations confirm the suitability of the recent theoretical developments (Zolezzi & Seminara 2001) that indicate the occurrence of two distinct regimes of morphodynamic influence, depending on the value of the width ratio of the channel β. The threshold value βR separating the upstream from the downstream influence regimes coincides with the resonant value discovered by Blondeaux & Seminara (1985). Indeed it is observed that upstream influence may occur only in relatively wide channels, while narrower stream…
An Optimized and Rapid DNA Extraction Method From Leaves of Grapevine Suitable for PCR-DGGE Based Analysis
2010
Molecular techniques and genetic studies require a fair amount of DNA of high quality in order to produce reliable and clear results (Li et al., 2007). In grapevine, the yield and quality of DNA can be significantly affected by secondary metabolites such as polyphenols, polysaccharides and tannins, that may be consistently abundant during the different stages of leaf development (Iandolino et al., 2004). The development of a simple, rapid and reliable method for the extraction of genomic DNA from grape leaves collected at several stages during development, as well as from healthy grape leaves and leaves infected by pathogenic microorganisms, was the main objective of this study. The protoco…
Towards the development of a fossil bone geochemical standard: An inter-laboratory study
2007
Ten international laboratories participated in an inter-laboratory comparison of a fossil bone composite with the objective of producing a matrix and structure-matched reference material for studies of the bio-mineralization of ancient fossil bone. We report the major and trace element compositions of the fossil bone composite, using in-situ method as well as various wet chemical digestion techniques. For major element concentrations, the intra-laboratory analytical precision (%RSDr) ranges from 7 to 18%, with higher percentages for Ti and K. The %RSDr are smaller than the inter-laboratory analytical precision (%RSDR; 100% was found for the high field strength elements (Hf, Th, Zr, Nb). The…
Evaluation of the laboratory prediction of surface properties of bituminous mixtures. Construction and Building Materials. Volume 23. Issue 2. Elsevi…
2009
An experimental and analytical investigation was carried out both in laboratory and in situ on wearing courses. The approach presented in this paper aims to predict the in situ density and surface properties of bituminous layers, during the phase of mix design in laboratory. Therefore, the main attempt of this study is to identify, amongst the commonly available laboratory equipments, the most adequate for producing specimens that, used for carrying out simple and reliable laboratory test, allow the prediction of the surface characteristics of the mixture as laid on site. This is done by comparing the data collected from an experimental site with those calculated from laboratory specimens c…
A Worldwide Perspective on COVID-19 and Diabetes Management in 22,820 Children from the SWEET Project: Diabetic Ketoacidosis Rates Increase and Glyce…
2021
Aims: To investigate the short-term effects of the first wave of COVID-19 on clinical parameters in children with type 1 diabetes (T1D) from 82 worldwide centers participating in the Better Control in Pediatric and Adolescent DiabeteS: Working to CrEate CEnTers of Reference (SWEET) registry. Materials and Methods: Aggregated data per person with T1D £21 years of age were compared between May/June 2020 (first wave), August/September 2020 (after wave), and the same periods in 2019. Hierarchic linear and logistic regression models were applied. Models were adjusted for gender, age-, and diabetes duration-groups. To distinguish the added burden of the COVID-19 pandemic, the centers were divided…
Study of Glycemic Variability Through Time Series Analyses (Detrended Fluctuation Analysis and Poincaré Plot) in Children and Adolescents with Type 1…
2016
Time series analysis provides information on blood glucose dynamics that is unattainable with conventional glycemic variability (GV) indices. To date, no studies have been published on these parameters in pediatric patients with type 1 diabetes. Our aim is to evaluate the relationship between time series analysis and conventional GV indices, and glycosylated hemoglobin (HbA1c) levels.This is a transversal study of 41 children and adolescents with type 1 diabetes. Glucose monitoring was carried out continuously for 72 h to study the following GV indices: standard deviation (SD) of glucose levels (mg/dL), coefficient of variation (%), interquartile range (IQR; mg/dL), mean amplitude of the la…
The role of morbid obesity in the promotion of metabolic disruptions and non-alcoholic steatohepatitis by Helicobacter Pylori
2016
Background Helicobacter pylory (HP) infection has been associated to an increased rate of type 2 diabetes (T2D) and liver disease through its effect on insulin resistance and systemic inflammation. However, results are inconstant and no studies exist in morbidly obese patients, in which both insulin resistance and inflammation coexist. Material and methods Cross-sectional study to evaluate the relationship between HP infection and alterations in carbohydrate metabolism, lipid profile, inflammation markers, and liver disease in patients awaiting for bariatric surgery. HP infection was histologically assessed in gastric antrum biopsy from 416 subjects. Liver biopsy was also available in 93 su…
Risk profiles in type 2 diabetes (metabolic syndrome): integration of IL-10 polymorphisms and laboratory parameters to identify vascular damages rela…
2010
Recently it has been reported that low serum IL-10 levels are associated with an increased susceptibility for metabolic syndrome and type 2 diabetes mellitus (T2DM). We investigated whether the -1087G/A (rs1800896), -824C/T (rs1800871), -597C/A (rs1800872) IL-10 polymorphisms were associated with type 2 diabetes in a study on a cohort of Italian Caucasians comprising 490 type 2 diabetic and 349 control subjects. Stratifying the data according to IL-10 genotypes, trends for the progressive increase of glucose and neutrophil levels were observed in -1087GG vs. -1087GA vs. -1087AA positive diabetic patients (-1087GG < -1087GA < -1087AA). In addition, evaluating the laboratory parameters accord…