Search results for "gradient"
showing 10 items of 725 documents
Increasing the drying efficiency of cylinder drying
2011
This PhD Thesis concentrates on paper drying: first on the drying rate in a cylinder covered with fabric, enhanced using hot air impingement through the fabric, and its potential effects on paper quality, and second, on the heat transfer rate from hot steam to paper through the cylinder shell. Cylinder drying is a drying method where a heated surface in contact with paper causes water removal from the latter by evaporation. Impingement through the fabric of hot air has been suggested to cause increase in the water removal and drying of paper. Increase in the drying rate by impingement of hot air was confirmed by laboratory tests and by simulations. In laboratory tests the increase in the dr…
Data from: Simultaneous age-dependent and age-independent sexual selection in the lekking black grouse (Lyrurus tetrix)
2016
Individuals' reproductive success is often strongly associated with their age, with typical patterns of early-life reproductive improvement and late-life senescence. These age-related patterns are due to the inherent trade-offs between life-history traits competing for a limited amount of resources available to the organisms. In males, such trade-offs are exacerbated by the resource requirements associated with the expression of costly sexual traits, leading to dynamic changes in trait expression throughout their life span. Due to the age dependency of male phenotypes, the relationship between the expression of male traits and mating success can also vary with male age. Hence, using longitu…
Data from: The role of partial incubation and egg repositioning within the clutch in hatching asynchrony and subsequent effects on breeding success
2019
The main mechanism to achieve hatching asynchrony (HA) for incubating birds is to start heating the eggs before clutch completion. This might be achieved through partial incubation and/or early incubation. Even in the absence of incubation behaviour during the laying phase, clutches still experience a certain degree of asynchrony. Recent studies have shown that eggs located in the centre of the nest receive more heat than peripheral ones during incubation. Since eggs receiving more heat would develop faster, we hypothesised that HA should be shorter in nests where eggs were moved homogeneously along the centre-periphery space during incubation compared to those nests where eggs repeatedly r…
Data from: Pace-of-life in a social insect: behavioral syndromes in ants shift along a climatic gradient
2017
Behavioral syndromes are correlations between behavioral traits, but their selective advantage under different environmental conditions is not well understood. Here, we used the pace-of-life hypothesis to predict how behavioral syndromes could vary along climatic gradients. This hypothesis states that populations experiencing different ecological conditions should differ in suites of physiological characteristics associated with behavioral and life-history traits. We examined the persistence of behavioral syndromes at multiple levels in the ant Temnothorax longispinosus along a climatic gradient in north-eastern USA. “Across populations”, we predicted that proactive phenotypes, which show h…
Isolation of Central Nervous System (CNS) Infiltrating Cells
2014
Leukocyte infiltration of the central nervous system (CNS) occurs under certain pathogenic conditions and most often results in severe disorders. Therefore, the isolation and analysis of such infiltrating cell populations is necessary for elucidating the underlying pathogenic mechanisms. Here we describe a simple and straightforward protocol for cell isolation from the inflamed CNS, which combines mechanical dissociation and enzymatic degradation of the tissue. Additionally, purification by Percoll gradient centrifugation provides a great yield of the infiltrating material. The isolated cells can be further used for downstream applications such as cell sorting, cellular or molecular analysi…
Isolation of nuclei and downstream processing of cell-type-specific nuclei from micro-dissected mouse brain regions – techniques and caveats
2020
AbstractThe mammalian brain consists of several structurally and functionally distinct regions equipped with an equally complex cell-type system. Due to its relevance in uncovering disease mechanisms, the study of cell-type-specific molecular signatures of different brain regions has increased. The rapid evolution of newer and cheaper sequencing techniques has also boosted the interest in cell-type-specific epigenetic studies. In fact, the nucleus holds most of the cell’s epigenetic information and is quite resistant to tissue dissociation processes as compared to cells. As such, nuclei are continually preferred over cells for epigenetic studies. However, the isolation of nuclei from cells …
Description of an improved method for Blastocystis hominis culture and axenization
1996
An improved method for Blastocystis hominis culture and axenization was developed in the present study. Stool samples were cultured in prereduced Boeck-Drbohlav NHI modified medium (with several modifications) supplemented with antibiotics (0.4% ampicillin, 0.1% streptomycin, 0.0006% amphotericin B). Axenization was performed by the combination of partial purification of B. hominis by Ficoll-metrizoic acid gradient and inoculation in fresh medium containing active antibiotics against remaining bacteria. A total of 25 strains were obtained by this procedure. The time required for axenization ranged between 3 and 5 weeks. The generation time of axenic strains ranged from 6.6 to 12.1 h (mean +…
A boosting approach for prostate cancer detection using multi-parametric MRI
2015
International audience; Prostate cancer has been reported as the second most frequently diagnosed men cancers in the world. In the last decades, new imaging techniques based on MRI have been developed in order to improve the diagnosis task of radiologists. In practise, diagnosis can be affected by multiple factors reducing the chance to detect potential lesions. Computer-aided detection and computer-aided diagnosis have been designed to answer to these needs and provide help to radiologists in their daily duties. In this study, we proposed an automatic method to detect prostate cancer from a per voxel manner using 3T multi-parametric Magnetic Resonance Imaging (MRI) and a gradient boosting …
Effects on lipoprotein subclasses of combined expression of human hepatic lipase and human apoB in transgenic rabbits
2003
Objective— The effects of combined expression of human hepatic lipase (HL) and human apolipoprotein B (apoB) on low-density lipoprotein (LDL) subclasses were examined in rabbits, a species naturally deficient in HL activity. Methods and Results— In apoB-transgenic rabbit plasma, >80% of the protein was found in the 1.006- to 1.050-g/mL fraction. Gradient gel electrophoresis (GGE) of this fraction revealed two distinct species, designated large and small LDL. A denser fraction (d=1.050 to 1.063 g/mL) contained small LDL as well as another discrete LDL subspecies, designated very small LDL. Expression of HL resulted in reductions in protein concentrations in the 1.006- to 1.050-g/mL densi…
Computational fluid dynamics simulation to evaluate aortic coarctation gradient with contrast-enhanced CT
2014
Coarctation of aorta (CoA) is a narrowing of the aorta leading to a pressure gradient (Delta P) across the coarctation, increased afterload and reduced peripheral perfusion pressures. Indication to invasive treatment is based on values of maximal (systolic) trans-coarctation Delta P. A computational fluid dynamic (CFD) approach is herein presented for the non-invasive haemodynamic assessment of Delta P across CoA. Patient-specific CFD simulations were created from contrast-enhanced computed tomography (CT) and appropriate flow boundary conditions. Computed Delta P was validated with invasive intravascular trans-CoA pressure measurements. Haemodynamic indices, including pressure loss coeffic…