On the reorientation of non-spherical prey particles in a feeding current

Potentially, non-spherical prey can be re-oriented in a flowfield and impact on the predator's feeding structures in a non-randommanner. Herein, we quantify a process whereby this passive reorientationoccurs, and present a model that predicts the orientation ofa spheroidal prey as a function of its shape, size and the characteristicsof the fluid flow. For a radial flow field, elongated prey tendto align with their long axis parallel to streamlines. Thistheory is well supported by our results from a laboratory studyof cylindrical particles in a siphon flow. The model is extendedto a more realistic representation of copepod feeding currents.In this context, the spatial scale over which this process isactive is proportional to     

Extensive sequence homologies among lectins from leguminous plants

The first twenty five residues of the amino terminal sequence of the β chains from lentil and pea lectins, of soybean and peanut agglutinins, and of the R and L subunits of phytohemagglutinin (PHA) were compared. Extensive homologies were found, ranging from near identity in the case of the β chains of lentil and pea lectins, to 24% identity between soybean agglutinin and L-PHA (assuming two deletions in the latter). Despite different sugar binding specificities, a common ancestry for the genes coding for leguminous lectins appears to be very likely.     

Standardization of Cardiopulmonary Roentgenograms in Infants and Children

Methods were devised to standardize cardiopulmonary radiographs of infants and children. With these techniques, films can be taken either at the end of inspiration and in systole, or at the end of inspiration alone. A statistical evaluation of these two methods demonstrated their superiority over the usual procedure. The use of these techniques is strongly recommended in patients of the pediatric age group.     

A correlation between the cellular composition of the spleen and the change in splenocyte chemiluminescence after laser irradiation]

Chemiluminescence (CL) of splenocytes of A/Sn mice (1.5-9-month old) was recorded after irradiation of the cells with lambda semiconductor laser at 820 nm (dose 1.1 x 10(3) J/m2, pulse repetition rate 292 Hz). Laser radiation was found to stimulate or suppress the spontaneous CL (SCL) of splenocytes, the amplitude and its sign depending on cellular composition of the spleen. Direct correlations between effect of laser radiation (per cent in changes in SCL) and per cent of plasmatic cells (r = 0.743, p < 0.001), neutrophils (r = 0.650, p < 0.001) and myelocytes and metamyelocytes (r = 0.507, p < 0.01) were established. The correlation with per cent of lymphocytes (r = -0.590, p < 0.001) was found to be a reverse one.     

Natural variation of outcrossing in the hermaphroditic nematode Pristionchus pacificus

Background  

Evolution of selfing can be associated with an increase in fixation of deleterious mutations, which in certain conditions can lead to species extinction. In nematodes, a few species evolved self-fertilization independently, making them excellent model systems to study the evolutionary consequences of this type of mating system.     

GMFilter and SXTestPlate: software tools for improving the SNPlex? genotyping system

Background  

Genotyping of single-nucleotide polymorphisms (SNPs) is a fundamental technology in modern genetics. The SNPlex™ mid-throughput genotyping system (Applied Biosystems, Foster City, CA, USA) enables the multiplexed genotyping of up to 48 SNPs simultaneously in a single DNA sample. The high level of automation and the large amount of data produced in a high-throughput laboratory require advanced software tools for quality control and workflow management.     

Visualization of Active Glucocerebrosidase in Rodent Brain with High Spatial Resolution following In Situ Labeling with Fluorescent Activity Based Probes

Gaucher disease is characterized by lysosomal accumulation of glucosylceramide due to deficient activity of lysosomal glucocerebrosidase (GBA). In cells, glucosylceramide is also degraded outside lysosomes by the enzyme glucosylceramidase 2 (GBA2) of which inherited deficiency is associated with ataxias. The interest in GBA and glucosylceramide metabolism in the brain has grown following the notion that mutations in the GBA gene impose a risk factor for motor disorders such as α-synucleinopathies. We earlier developed a β-glucopyranosyl-configured cyclophellitol-epoxide type activity based probe (ABP) allowing in vivo and in vitro visualization of active molecules of GBA with high spatial resolution. Labeling occurs through covalent linkage of the ABP to the catalytic nucleophile residue in the enzyme pocket. Here, we describe a method to visualize active GBA molecules in rat brain slices using in vivo labeling. Brain areas related to motor control, like the basal ganglia and motor related structures in the brainstem, show a high content of active GBA. We also developed a β-glucopyranosyl cyclophellitol-aziridine ABP allowing in situ labeling of GBA2. Labeled GBA2 in brain areas can be identified and quantified upon gel electrophoresis. The distribution of active GBA2 markedly differs from that of GBA, being highest in the cerebellar cortex. The histological findings with ABP labeling were confirmed by biochemical analysis of isolated brain areas. In conclusion, ABPs offer sensitive tools to visualize active GBA and to study the distribution of GBA2 in the brain and thus may find application to establish the role of these enzymes in neurodegenerative disease conditions such as α-synucleinopathies and cerebellar ataxia.     

Genome-Wide Association Study in an Admixed Case Series Reveals IL12A as a New Candidate in Beh?et Disease

Introduction

The etiology of Behçet’s disease (BD) is unknown, but widely considered an excessive T-cell mediated inflammatory response in a genetically susceptible host. Recent genome-wide association studies (GWAS) have shown limited number of novel loci-associations. The rarity and unequal distribution of the disease prevalence amongst different ethnic backgrounds have hampered the use of GWAS in cohorts of mixed ethnicity and sufficient sample size. However, novel statistical approaches have now enabled GWAS in admixed cohorts.

Methods

We ran a GWAS on 336 BD cases and 5,843 controls. The cases consisted of Western Europeans, Middle Eastern and Turkish individuals. Participants from the Generation R study, a multiethnic birth cohort in Rotterdam, The Netherlands were used as controls. All samples were genotyped and data was combined. Linear regression models were corrected for population stratification using Genomic Principal Components and Linear Mixed Modelling. Meta-analysis was performed on selected results previously published.

Results

We identified SNPs associated at genome-wide significant level mapping to the 6p21.33 (HLA) region. In addition to this known signal two potential novel associations on chromosomes 6 and 18 were identified, yet with low minor allele frequencies. Extended meta-analysis reveal a GWS association with the IL12A variant rs17810546 on chromosome 3.

Discussion

We demonstrate that new statistical techniques enable GWAS analyses in a limited sized cohort of mixed ethnicity. After implementation, we confirmed the central role of the HLA region in the disease and identified new regions of interest. Moreover, we validated the association of a variant in the IL2A gene by meta-analysis with previous work. These findings enhance our knowledge of genetic associations and BD, and provide further justification for pursuing collective initiatives in genetic studies given the low prevalence of this and other rare diseases.