Analysis of genetic factors influencing alpha-defensin gene expression

Background: The DEFA1A3 locus on chromosome 8p23.1 has been known to exhibit copy number variation (between 3 and 16 copies) and to include either the DEFA1 gene or the DEFA3 gene in any repeat. These two genes encode the Human Neutrophil Peptides HNPs 1-3, antimicrobial peptides implicated in the innate immune response. Objectives: The primary aim of this study was to determine whether there is any significant relationship between alpha defensin copy number and expression levels. The secondary aim was to understand more about 6836028G, a synonymous variant in exon 2 of the DEFA1A3 locus which affects a valine codon. Results and Conclusions: Levels of DEFA3 expression in mRNA are not simply proportional to genomic copy number; in cDNA DEFA3 appears to be expressed about 6-7 times more per copy than DEFA1. A similar relationship is also reflected in the variant 6836028G, which is underrepresented by a factor of about 1.4-fold in cDNA relative to genomic DNA; we assume that this variant might accompany only the DEFA1 gene, due to low levels of 6836028G in cDNA

Ground displacement trends in an urban environment using multi-temporal inSAR analysis and two decades of multi-sensor satellite-based SAR imagery

This exploratory research used three sets of single polarized synthetic aperture radar (SAR) satellite data and a multi-temporal radar interferometry (InSAR) methodology to determine the spatial evolution and ground displacement trends of several industrial parks located in the metropolitan area of Bucharest, Romania. From 70candidate areas, 20 large industrial parks were selected for analysis and interpretation. InSAR analysis used SAR data acquired between 1992 and 2014 by ERS-1/-2, ENVISAT, and TerraSAR-X satellites. Ground movement patterns identified before and after 2000 were linked to groundwater table investigations based on 25 water wells, located on or in the proximity of these areas. The analysis revealed an initial subsidence or no change in uplift areas before 2000, followed by a return to zonal movement. This trend may also be related to the shutting down of industries that consumed large amounts of water, which increased deep groundwater pressure. Only one continuous subsidence trend was identified for an industrial area located south of the city, an area which continues to be active over time. Ongoing research is focused on using traditional geological andgeomorphologic investigations, as well as comparisons with fieldGlobal Navigation Satellite System (GNSS) data.info:eu-repo/semantics/submittedVersio

Cryosphere Applications

Synthetic aperture radar (SAR) provides large coverage and high resolution, and it has been proven to be sensitive to both surface and near-surface features related to accumulation, ablation, and metamorphism of snow and firn. Exploiting this sensitivity, SAR polarimetry and polarimetric interferometry found application to land ice for instance for the estimation of wave extinction (which relates to sub surface ice volume structure) and for the estimation of snow water equivalent (which relates to snow density and depth). After presenting these applications, the Chapter proceeds by reviewing applications of SAR polarimetry to sea ice for the classification of different ice types, the estimation of thickness, and the characterisation of its surface. Finally, an application to the characterisation of permafrost regions is considered. For each application, the used (model-based) decomposition and polarimetric parameters are critically described, and real data results from relevant airborne campaigns and space borne acquisitions are reported

Segregation analysis identifies specific alpha-defensin (DEFA1A3) SNP–CNV haplotypes in predisposition to IgA nephropathy

BACKGROUND: Immunoglobulin A (IgA) nephropathy is a disorder of the immune system affecting kidney function, and genome-wide association studies (GWAS) have defined numerous loci with associated variation, all implicating components of innate or adaptive immunity. Among these, single nucleotide polymorphisms (SNPs) in a region including the multiallelic copy number variation (CNV) of DEFA1A3 are associated with IgA nephropathy in both European and Asian populations. At present, the precise factors underlying the observed associations at DEFA1A3 have not been defined, although the key alleles differ between Asian and European populations, and multiple independent factors may be involved even within a single population. METHODS: In this study, we measured DEFA1A3 copy number in UK family trios with an offspring affected by IgA nephropathy, used the population distributions of joint SNP-CNV haplotypes to infer the likely segregation in trios, and applied transmission disequilibrium tests (TDT) to examine joint SNP-CNV haplotypes for over- or undertransmission into affected offspring from heterozygous parents. RESULTS AND CONCLUSIONS: We observed overtransmission of 3-copy class 2 haplotypes (raw p = 0.029) and some evidence for under-transmission of 3-copy class 1 haplotypes (raw p = 0.051), although these apparent effects were not statistically significant after correction for testing of multiple haplotypes

High sensitivity measurement of implanted As in the presence of Ge in GexSi1−x/Si layered alloys using trace element accelerator mass spectrometry

This article discusses high sensitivity measurement of implanted As in the presence of Ge in Ge(x)Si(1-x)/Si layered alloys using trace element accelerator mass spectrometry

A 45-year time series of dune mobility indicating constant windiness over the central Sahara

Although evidence is mounting that links global warming to changes in atmospheric dynamics over the Atlantic realm, similar studies over the African continent are lacking. And even if such models would exist, it would be difficult to verify their validity due to the paucity of meteorological observations and anemometers in the central Sahara. A pragmatic way around this problem is to monitor barchan dune velocity as a proxy for the windiness of desert areas. Dune migration rates are a measure of the amount of work done by the wind which does not require field measurements but can be observed from space instead. This paper presents a novel application of the remote sensing tool COSI-Corr for the construction of time series of dune mobility from sequences of optical satellite imagery. The technique has been applied to the Bodélé Depression in northern Chad, to demonstrate that dune migration rates in the central Sahara have been remarkably constant for nearly half a century, leading us to conclude that wind velocities have not changed more than 0.2% per year over that period. It is therefore unlikely that the frequency and intensity of dust storms originating from this ‘hot spot’ has significantly changed over the past decades either

Monte Carlo simulation and experimental studies of the production of neutron-rich medical isotopes using a particle accelerator.

The developments of nuclear medicine lead to an increasing demand for the production of radioisotopes with suitable nuclear and chemical properties. Furthermore, from the literature it is evident that the production of radioisotopes using charged-particle accelerators instead of nuclear reactors is gaining increasing popularity. The main advantages of producing medical isotopes with accelerators are carrier free radionuclides of short lived isotopes, improved handling, reduction of the radioactive waste, and lower cost of isotope fabrication. Proton-rich isotopes are the result of nuclear interactions between enriched stable isotopes and energetic protons. An interesting observation is that during the production of proton-rich isotopes, fast and intermediately fast neutrons from nuclear reactions such as (p,xn) are also produced as a by-product in the nuclear reactions. This observation suggests that it is perhaps possible to use these neutrons to activate secondary targets for the production of neutron-rich isotopes. The study of secondary radioisotope production with fast neutrons from (p,xn) reactions using a particle accelerator is the main goal of the research in this thesis

Analysis of genetic factors influencing alpha-defensin gene expression

Background: The DEFA1A3 locus on chromosome 8p23.1 has been known to exhibit copy number variation (between 3 and 16 copies) and to include either the DEFA1 gene or the DEFA3 gene in any repeat. These two genes encode the Human Neutrophil Peptides HNPs 1-3, antimicrobial peptides implicated in the innate immune response. Objectives: The primary aim of this study was to determine whether there is any significant relationship between alpha defensin copy number and expression levels. The secondary aim was to understand more about 6836028G, a synonymous variant in exon 2 of the DEFA1A3 locus which affects a valine codon. Results and Conclusions: Levels of DEFA3 expression in mRNA are not simply proportional to genomic copy number; in cDNA DEFA3 appears to be expressed about 6-7 times more per copy than DEFA1. A similar relationship is also reflected in the variant 6836028G, which is underrepresented by a factor of about 1.4-fold in cDNA relative to genomic DNA; we assume that this variant might accompany only the DEFA1 gene, due to low levels of 6836028G in cDNA