541 research outputs found
Spherical Relativistic Hartree theory in a Woods-Saxon basis
The Woods-Saxon basis has been suggested to replace the widely used harmonic
oscillator basis for solving the relativistic mean field (RMF) theory in order
to generalize it to study exotic nuclei. As examples, relativistic Hartree
theory is solved for spherical nuclei in a Woods-Saxon basis obtained by
solving either the Schr\"odinger equation or the Dirac equation (labelled as
SRHSWS and SRHDWS, respectively and SRHWS for both). In SRHDWS, the negative
levels in the Dirac Sea must be properly included. The basis in SRHDWS could be
smaller than that in SRHSWS which will simplify the deformed problem. The
results from SRHWS are compared in detail with those from solving the spherical
relativistic Hartree theory in the harmonic oscillator basis (SRHHO) and those
in the coordinate space (SRHR). All of these approaches give identical nuclear
properties such as total binding energies and root mean square radii for stable
nuclei. For exotic nuclei, e.g., Ca, SRHWS satisfactorily reproduces the
neutron density distribution from SRHR, while SRHHO fails. It is shown that the
Woods-Saxon basis can be extended to more complicated situations for exotic
nuclei where both deformation and pairing have to be taken into account.Comment: 12 pages, 9 figure
Age-related gene and miRNA expression changes in airways of healthy individuals
© 2019, The Author(s). Knowledge on age-related miRNA changes in healthy individuals and their interaction with mRNAs is lacking. We studied age-related mRNA and miRNA expression changes and their interactions in normal airways. RNA and small RNA sequencing was performed on bronchial biopsies of 86 healthy individuals (age: 18–73) to determine age-related expression changes. Per age-related miRNA we determined the enrichment of age-related predicted targets and their correlation. We identified 285 age-related genes and 27 age-related miRNAs. Pathway enrichment showed that genes higher expressed with age were involved in synapse-related processes. Genes lower expressed with age were involved in cell cycle regulation, the immune system and DNA damage/repair. MiR-146a-5p, miR-146b-5p and miR-142-5p were lower expressed with increasing age and we found a significant enrichment for predicted targets of these miRNAs among genes that were higher expressed with age. The expression levels of the enriched predicted targets RIMS2 and IGSF1 were negatively correlated with both miR-146a-5p and miR-146b-5p. RIMS2 was present in the enriched process, i.e. positive regulation of synaptic transmission. In conclusion, genes decreased with ageing are involved in several of the ageing hallmarks. Genes higher expressed with ageing were involved in synapse-related processes, of which RIMS2 is potentially regulated by two age-related miRNAs
Reproductive performance of Norwegian cattle from 1985 to 2005: trends and seasonality
Declining reproductive performance is a serious breeding concern in many countries. To reveal the situation in Norwegian cattle, trends in reproductive performance were studied using insemination reports from 1985 to 2005 and data based on herd recording files from 1989 to 2005. The total number of first services was 469.765 in 1985 declining to 335.712 in 2005. The number of recorded herds and animals declined from 21.588 to 14.718 and 360.289 to 309.452 from 1989 to 2005, respectively. Sixty days non-return rate after single inseminations (NR60) increased from 68.1 in 1985 to 72.7% in 2005 (p < 0.001) and the number of services per inseminated animal (NIA) decreased from 1.8 to 1.6 (p < 0.001) from 1985 to 2005. However, return rates 0–3 days post insemination (RR0-3) increased from 6 to 12% in the same period (p < 0.001). NR60 was higher and the RR0-3 was lower in the summer season compared to the winter season during the whole period. A fertility index (FS), has been calculated from the herd recording files each year from 1989 to 2005. The average FS-index did not show a significant trend and the calving interval was also fairly constant between 12.4 and 12.6 months during this period. The average interval from calving to first and last insemination, respectively, increased from a low of 79 and 102 days in 1990 to a high of 86 and 108 days in 2005. Both intervals were consistently longer for cows in first lactation than for cows in later lactations. The percentage of inseminated animals reported culled because of poor fertility decreased from 6.0% in 1989 to 4.6% in 1996 and thereafter again increased to 6% in 2005. In conclusion, most fertility measures, mainly comprising the Norwegian Red (NRF) breed, show a relatively high level of reproductive performance with a positive or a relatively constant trend during the last two decades
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Bioavailability in soils
The consumption of locally-produced vegetables by humans may be an important exposure pathway for soil contaminants in many urban settings and for agricultural land use. Hence, prediction of metal and metalloid uptake by vegetables from contaminated soils is an important part of the Human Health Risk Assessment procedure. The behaviour of metals (cadmium, chromium, cobalt, copper, mercury, molybdenum, nickel, lead and zinc) and metalloids (arsenic, boron and selenium) in contaminated soils depends to a large extent on the intrinsic charge, valence and speciation of the contaminant ion, and soil properties such as pH, redox status and contents of clay and/or organic matter. However, chemistry and behaviour of the contaminant in soil alone cannot predict soil-to-plant transfer. Root uptake, root selectivity, ion interactions, rhizosphere processes, leaf uptake from the atmosphere, and plant partitioning are important processes that ultimately govern the accumulation ofmetals and metalloids in edible vegetable tissues. Mechanistic models to accurately describe all these processes have not yet been developed, let alone validated under field conditions. Hence, to estimate risks by vegetable consumption, empirical models have been used to correlate concentrations of metals and metalloids in contaminated soils, soil physico-chemical characteristics, and concentrations of elements in vegetable tissues. These models should only be used within the bounds of their calibration, and often need to be re-calibrated or validated using local soil and environmental conditions on a regional or site-specific basis.Mike J. McLaughlin, Erik Smolders, Fien Degryse, and Rene Rietr
Stimulation of homology-directed gene targeting at an endogenous human locus by a nicking endonuclease
Homologous recombination (HR) is a highly accurate mechanism of DNA repair that can be exploited for homology-directed gene targeting. Since in most cell types HR occurs very infrequently (∼10−6 to 10−8), its practical application has been largely restricted to specific experimental systems that allow selection of the few cells that become genetically modified. HR-mediated gene targeting has nonetheless revolutionized genetics by greatly facilitating the analysis of mammalian gene function. Recent studies showed that generation of double-strand DNA breaks at specific loci by designed endonucleases greatly increases the rate of homology-directed gene repair. These findings opened new perspectives for HR-based genome editing in higher eukaryotes. Here, we demonstrate by using donor DNA templates together with the adeno-associated virus (AAV) Rep78 and Rep68 proteins that sequence- and strand-specific cleavage at a native, predefined, human locus can also greatly enhance homology-directed gene targeting. Our findings argue for the development of other strategies besides direct induction of double-strand chromosomal breaks to achieve efficient and heritable targeted genetic modification of cells and organisms. Finally, harnessing the cellular HR pathway through Rep-mediated nicking expands the range of strategies that make use of AAV elements to bring about stable genetic modification of human cells
Fungal enzyme sets for plant polysaccharide degradation
Enzymatic degradation of plant polysaccharides has many industrial applications, such as within the paper, food, and feed industry and for sustainable production of fuels and chemicals. Cellulose, hemicelluloses, and pectins are the main components of plant cell wall polysaccharides. These polysaccharides are often tightly packed, contain many different sugar residues, and are branched with a diversity of structures. To enable efficient degradation of these polysaccharides, fungi produce an extensive set of carbohydrate-active enzymes. The variety of the enzyme set differs between fungi and often corresponds to the requirements of its habitat. Carbohydrate-active enzymes can be organized in different families based on the amino acid sequence of the structurally related catalytic modules. Fungal enzymes involved in plant polysaccharide degradation are assigned to at least 35 glycoside hydrolase families, three carbohydrate esterase families and six polysaccharide lyase families. This mini-review will discuss the enzymes needed for complete degradation of plant polysaccharides and will give an overview of the latest developments concerning fungal carbohydrate-active enzymes and their corresponding families
Total 18F-dopa PET tumour uptake reflects metabolic endocrine tumour activity in patients with a carcinoid tumour
Positron emission tomography (PET) using 6-[(18)F]fluoro-L-dihydroxyphenylalanine ((18)F-dopa) has an excellent sensitivity to detect carcinoid tumour lesions. (18)F-dopa tumour uptake and the levels of biochemical tumour markers are mediated by tumour endocrine metabolic activity. We evaluated whether total (18)F-dopa tumour uptake on PET, defined as whole-body metabolic tumour burden (WBMTB), reflects tumour load per patient, as measured with tumour markers.
Seventy-seven consecutive carcinoid patients who underwent an (18)F-dopa PET scan in two previously published studies were analysed. For all tumour lesions mean standardised uptake values (SUVs) at 40% of the maximal SUV and tumour volume on (18)F-dopa PET were determined and multiplied to calculate a metabolic burden per lesion. WBMTB was the sum of the metabolic burden of all individual lesions per patient. The 24-h urinary serotonin, urine and plasma 5-hydroxindoleacetic acid (5-HIAA), catecholamines (nor)epinephrine, dopamine and their metabolites, measured in urine and plasma, and serum chromogranin A served as tumour markers.
All but 1 were evaluable for WBMTB; 74 patients had metastatic disease. (18)F-dopa PET detected 979 lesions. SUV(max) on (18)F-dopa PET varied up to 29-fold between individual lesions within the same patients. WBMTB correlated with urinary serotonin (r = 0.51) and urinary and plasma 5-HIAA (r = 0.78 and 0.66). WBMTB also correlated with urinary norepinephrine, epinephrine, dopamine and plasma dopamine, but not with serum chromogranin A.
Tumour load per patient measured with (18)F-dopa PET correlates with tumour markers of the serotonin and catecholamine pathway in urine and plasma in carcinoid patients, reflecting metabolic tumour activity
Effectiveness of the universal prevention program 'Healthy School and Drugs': Study protocol of a randomized clustered trial
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90260.pdf (publisher's version ) (Open Access)Background: Substance use is highly prevalent among Dutch adolescents. The Healthy School and Drugs program is a nationally implemented school-based prevention program aimed at reducing early and excessive substance use among adolescents. Although the program's effectiveness was tested in a quasi-experimental design before, many program changes were made afterwards. The present study, therefore, aims to test the effects of this widely used, renewed universal prevention program.
Methods/Design: A randomized clustered trial will be conducted among 3,784 adolescents of 23 secondary schools in The Netherlands. The trial has three conditions; two intervention conditions (i.e., e-learning and integral) and a control condition. The e-learning condition consists of three digital learning modules (i.e., about alcohol, tobacco, and marijuana) that are sequentially offered over the course of three school years (i.e., grade 1, grade 2, and grade 3). The integral condition consists of parental participation in a parental meeting on substance use, regulation of substance use, and monitoring and counseling of students' substance use at school, over and above the three digital modules. The control condition is characterized as business as usual. Participating schools were randomly assigned to either an intervention or control condition. Participants filled out a digital questionnaire at baseline and will fill out the same questionnaire three more times at follow-up measurements (8, 20, and 32 months after baseline). Outcome variables included in the questionnaire are the percentage of binge drinking (more than five drinks per occasion), the average weekly number of drinks, and the percentage of adolescents who ever drunk a glass of alcohol and the percentage of adolescents who ever smoked a cigarette or a joint respectively for tobacco and marijuana.
Discussion: This study protocol describes the design of a randomized clustered trial that evaluates the effectiveness of a school-based prevention program. We expect that significantly fewer adolescents will engage in early or excessive substance use behaviors in the intervention conditions compared to the control condition as a direct result of the intervention. We expect that the integral condition will yield most positive results, compared with the e-learning condition and control condition.10 p
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High fat diet modifies the association of lipoprotein lipase gene polymorphism with high density lipoprotein cholesterol in an Asian Indian population
Background
Single nucleotide polymorphisms (SNPs) in lipoprotein lipase gene (LPL) have been shown to influence metabolism related to lipid phenotypes. Dietary factors have been shown to modify the association between LPL SNPs and lipids; however, to date, there are no studies in South Asians. Hence, we tested for the association of four common LPL SNPs with plasma lipids and examined the interactions between the SNPs and dietary factors on lipids in 1,845 Asian Indians.
Methods
The analysis was performed in 788 Type 2 diabetes cases and 1,057 controls randomly chosen from the cross-sectional Chennai Urban Rural Epidemiological Study. Serum triacylglycerol (TAG), serum total cholesterol, and high-density lipoprotein cholesterol (HDL-C) were measured using a Hitachi-912 autoanalyzer (Roche Diagnostics GmbH, Mannheim, Germany). Dietary intake was assessed using a semi-quantitative food frequency questionnaire. The SNPs (rs1121923, rs328, rs4922115 and rs285) were genotyped by polymerase chain reaction followed by restriction enzyme digestion and 20% of samples were sequenced to validate the genotypes obtained. Statistical Package for Social Sciences for Windows version 22.0 (SPSS, Chicago, IL) was used for statistical analysis.
Results
After correction for multiple testing and adjusting for potential confounders, SNPs rs328 and rs285 showed association with HDL-C (P = 0.0004) and serum TAG (P = 1×10−5), respectively. The interaction between SNP rs1121923 and fat intake (energy %) on HDL-C (P = 0.003) was also significant, where, among those who consumed a high fat diet (28.4 ± 2.5%), the T allele carriers (TT + XT) had significantly higher HDL-C concentrations (P = 0.0002) and 30% reduced risk of low HDL-C levels compared to the CC homozygotes. None of the interactions on other lipid traits were statistically significant.
Conclusion
Our findings suggest that individuals carrying T allele of the SNP rs1121923 have increased HDL-C levels when consuming a high fat diet compared to CC homozygotes. Our finding warrants confirmation in prospective studies and randomized controlled trials
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