Applied aspects of Rhodococcus genetics

Eubacteria of the genus Rhodococcus are a diverse group of microorganisms commonly found in many environmental niches from soils to seawaters and as plant and animal pathogens. They exhibit a remarkable ability to degrade many organic compounds and their economic importance is becoming increasingly apparent. Although their genetic organisation is still far from understood, there have been many advances in recent years. Reviewed here is the current knowledge of rhodococci relating to gene transfer, recombination, plasmid replication and functions, cloning vectors and reporter genes, gene expression and its control, bacteriophages, insertion sequences and genomic rearrangements. Further fundamental studies of Rhodococcus genetics and the application of genetic techniques to the these bacteria will be needed for their continued biotechnological exploitation.

Millimeter-wave and submillimeter-wave imaging for security and surveillance

Passive equipments operating in the 30-300 GHZ (millimeter wave) band are compared to those in the 300 GHz-3 THz (submillimeter band). Equipments operating in the submillimeter band can measure distance and also spectral information and have been used to address new opportunities in security. Solid state spectral information is available in the submillimeter region making it possible to identify materials, whereas in millimeter region bulk optical properties determine the image contrast. The optical properties in the region from 30 GHz to 3 THz are discussed for some typical inorganic and organic solids. in the millimeter-wave region of the spectrum, obscurants such as poor weather, dust, and smoke can be penetrated and useful imagery generated for surveillance. in the 30 GHZ-3 THZ region dielectrics such as plastic and cloth are also transparent and the detection of contraband hidden under clothing is possible. A passive millimeter-wave imaging concept based on a folded Schmidt camera has been developed and applied to poor weather navigation and security. The optical design uses a rotating mirror and is folded using polarization techniques. The design is very well corrected over a wide field of view making it ideal for surveillance, and security. This produces a relatively compact imager which minimizes the receiver count.

Pathogenicity and molecular genetics of O-specific side-chain lipopolysaccharides of Escherichia coli

Lipopolysaccharide (LPS), a glycolipid molecule found on the outer leaflet of outer membranes of gram-negative bacteria, consists of three moieties: lipid A, core oligosaccharide, and the O-specific polysaccharide chain. The O-specific side chain, which extends to the extracellular milieu, plays an important role in pathogenicity, especially during the initial stages of infection, because of its ability to interact with serum complement. In recent years, several laboratories have used recombinant DNA tools to determine, at the molecular level, the organization, expression, and regulation of genes involved in LPS biosynthesis in Salmonella and Escherichia coli. An increased understanding of the molecular aspects of the O-specific side-chain genes will shed light on the intimate details related with the formation of the O-specific side chain, its assembly onto the lipid A--core, and the translocation and insertion of the complete LPS molecule into the outer membrane. It will also contribute to the understanding of the evolution of these genes and the correlation of chemical diversity of O-specific side chains with the genetic diversity of O-specific side-chain genes. In addition, since the O-specific side chains are involved in the pathogenicity of medically important gram-negative bacteria, a basic understanding of the regulation and expression of O-specific side chain LPS genes will contribute to the field of molecular pathogenesis. This article provides an overview of the role of O-specific side chains in septicemic infections and also discusses the current status of molecular genetic studies on O-specific side-chain genes from E. coli.

Magneto-optical trapping and background-free imaging for atoms near nanostructured surfaces

We demonstrate a combined magneto-optical trap and imaging system that is suitable for the investigation of cold atoms near surfaces. In particular, we are able to trap atoms close to optically scattering surfaces and to image them with an excellent signal-to-noise ratio. We also demonstrate a simple magneto-optical atom cloud launching method. We anticipate that this system will be useful for a range of experimental studies of novel atom-surface interactions and atom trap miniaturization.

Radiochromic film imaging spectroscopy of laser-accelerated proton beams

This article reports on an experimental method to fully reconstruct laser-accelerated proton beam parameters called radiochromic film imaging spectroscopy (RIS). RIS allows for the characterization of proton beams concerning real and virtual source size, envelope- and microdivergence, normalized transverse emittance, phase space, and proton spectrum. This technique requires particular targets and a high resolution proton detector. Therefore thin gold foils with a microgrooved rear side were manufactured and characterized. Calibrated GafChromic radiochromic film (RCF) types MD-55, HS, and HD-810 in stack configuration were used as spatial and energy resolved film detectors. The principle of the RCF imaging spectroscopy was demonstrated at four different laser systems. This can be a method to characterize a laser system with respect to its proton-acceleration capability. In addition, an algorithm to calculate the spatial and energy resolved proton distribution has been developed and tested to get a better idea of laser-accelerated proton beams and their energy deposition with respect to further applications.

Imaging adiabatic control of charge transfer in molecules

Charge transfer is a subfemtosecond process in molecules that creates chemical and electronic structure changes. At the quantum level the process can be coherently controlled by ultrashort light pulses. We show how the charge transfer process can be manipulated using a combination of dynamic and static fields and predict how this can be observed experimentally by imaging with photoionization.

Impact of Age on the Importance of Systolic and Diastolic Blood Pressures for Stroke Risk:The MOnica, Risk, Genetics, Archiving, and Monograph (MORGAM) Project

This study investigates age-related shifts in the relative importance of systolic (SBP) and diastolic (DBP) blood pressures as predictors of stroke and whether these relations are influenced by other cardiovascular risk factors. Using 34 European cohorts from the MOnica, Risk, Genetics, Archiving, and Monograph (MORGAM) Project with baseline between 1982 and 1997, 68 551 subjects aged 19 to 78 years, without cardiovascular disease and not receiving antihypertensive treatment, were included. During a mean of 13.2 years of follow-up, stroke incidence was 2.8%. Stroke risk was analyzed using hazard ratios per 10-mm Hg/5-mm Hg increase in SBP/DBP by multivariate-adjusted Cox regressions, including SBP and DBP simultaneously. Because of nonlinearity, DBP was analyzed separately for DBP =71 mm Hg and DBP

Design, recruitment, logistics, and data management of the GEHA (Genetics of Healthy Ageing) project

In 2004, the integrated European project GEHA (Genetics of Healthy Ageing) was initiated with the aim of identifying genes involved in healthy ageing and longevity. The first step in the project was the recruitment of more than 2500 pairs of siblings aged 90 years or more together with one younger control person from 15 areas in 11 European countries through a coordinated and standardised effort. A biological sample, preferably a blood sample, was collected from each participant, and basic physical and cognitive measures were obtained together with information about health, life style, and family composition. From 2004 to 2008 a total of 2535 families comprising 5319 nonagenarian siblings were identified and included in the project. In addition, 2548 younger control persons aged 50-75 years were recruited. A total of 2249 complete trios with blood samples from at least two old siblings and the younger control were formed and are available for genetic analyses (e.g. linkage studies and genome-wide association studies). Mortality follow-up improves the possibility of identifying families with the most extreme longevity phenotypes. With a mean follow-up time of 3.7 years the number of families with all participating siblings aged 95 years or more has increased by a factor of 5 to 750 families compared to when interviews were conducted. Thus, the GEHA project represents a unique source in the search for genes related to healthy ageing and longevity.

Genome-wide linkage analysis for human longevity: Genetics of healthy aging study

Clear evidence exists for heritability of humanlongevity, and much interest is focused on identifying genes associated with longer lives. To identify such longevity alleles, we performed the largest genome-wide linkage scan thus far reported. Linkage analyses included 2118nonagenarian Caucasian sibling pairs that have been enrolled in 15 study centers of 11 European countries as part of the Genetics of Healthy Aging (GEHA) project. In the joint linkage analyses, we observed four regions that show linkage with longevity; chromosome 14q11.2 (LOD = 3.47), chromosome 17q12-q22 (LOD = 2.95), chromosome 19p13.3-p13.11 (LOD = 3.76), and chromosome 19q13.11-q13.32 (LOD = 3.57). To fine map these regions linked to longevity, we performed association analysis using GWAS data in a subgroup of 1228 unrelated nonagenarian and 1907 geographically matched controls. Using a fixed-effect meta-analysis approach, rs4420638 at the TOMM40/ APOE/APOC1 gene locus showed significant association with longevity (P-value = 9.6 × 10). By combined modeling of linkage and association, we showed that association of longevity with APOEe4 and APOEe2 alleles explain the linkage at 19q13.11-q13.32 with P-value = 0.02 and P-value = 1.0 × 10, respectively. In the largest linkage scan thus far performed for human familial longevity, we confirm that the APOE locus is a longevity gene and that additional longevity loci may be identified at 14q11.2, 17q12-q22, and 19p13.3-p13.11. As the latter linkage results are not explained by common variants, we suggest that rare variants play an important role in human familial longevity.

Conservation genetics of Ireland's sole population of the River water crowfoot (Ranunculus fluitans Lam.)

Populations of many freshwater species are becoming increasingly threatened as a result of a wide range of anthropogenically mediated factors. In the present study, we wanted to assess levels and patterns of genetic diversity in Ireland's sole population of the River water crowfoot (Ranunculus fluitans), which is restricted to a 12 km stretch of a single river, to assist the formation of conservation strategies. Analysis using amplified fragment length polymorphism (AFLP) indicated comparable levels of genetic diversity to those exhibited by a more extensive population of the species in England, and revealed no evidence of clonal reproduction. Allele-specific PCR analysis of five nuclear single nucleotide polymorphisms (SNPs) indicated no evidence of hybridization with its more abundant congener Ranunculus penicillatus, despite previous anecdotal reports of the occurrence of hybrids. Although the population currently exhibits healthy levels of genetic diversity and is not at risk of genetic assimilation via hybridization with R. penicillatus, it still remains vulnerable to other factors such as stochastic events and invasive species. © 2013 Elsevier B.V. All rights reserved.

Sequencing and its consequences:Path dependence and the relationships between genetics and medicalization

Both advocacy for and critiques of the Human Genome Project assume a self-sustaining relationship between genetics and. medicalization. However, this assumption ignores the ways in which the meanings of genetic research are conditional on its position in sequences of events. Based, on analyses of three conditions for which at least one putative gene or genetic marker has been identified, this article argues that critical junctures in the institutional stabilization of phenotypes and the mechanisms that sustain such classifications over time configure the practices and meanings of genetic research. Path dependence is critical to understanding the lack of consistent fit between genetics and medlcalization.