Genetic background and environmental effects on single nucleotide polymorphisms in the NADPH pathway

A major focus in modern genomics is determining the connection between genotypes and quantifying phenotypes. In this connection, many factors come into play including different genetic backgrounds, genetic variation at a locus, and environmental conditions. Genetic variation in Drosophila melanogaster, and specifically the simple polymorphisms within Malic enzyme (Men), can provide insight into the pathways between genotypes and phenotypes. Globally, there are two polymorphic sites in the malic enzyme gene. On site is near the protein (MEN) active site and found at an allelic frequency of 50% glycine amino acid and 50% alanine amino acid. The second polymorphism is buried within the protein and found at an allelic frequency of 90% methionine amino acid and 10% leucine amino acid. To determine the complexity of the pathway between genotypes and phenotypes, multiple genetic backgrounds for each genotype, using multiple D. melanogaster lines, were included to explore and quantify genetic background effects, and paraquat was used to induce oxidative stress. The biochemical characteristics of the alleles varied significantly between the genotypes under benign conditions and both polymorphic sites effected some phenotypes. The first site played a role in the MEN Vmax and Km; the glycine allele had 14% higher Vmax activity than the alanine allele and the glycine allele had 8% higher Km than the alanine allele. The second site influenced the Km and Vmax/Km ratio (relative activity); the methionine allele had 34% higher malate Km than the leucine allele the leucine allele had 52% higher relative activity than the methionine allele. Interestingly, the protein product encoded by the rarer allele, leucine, had a higher relative activity and lower Km concentration, having a large impact on the enzymatic phenotype. These extreme phenotypes of that allele may be an indication of the why the allele is maintained at 10% across populations. Different lines with the same genotype had different biochemical phenotypes, indicating the importance of backgrounds effects influencing the final phenotype. Further, the flies’ phenotypes differed between benign and oxidative stress conditions. Flies exposed to paraquat had a decrease in MEN Vmax, and the MEN alleles did not significantly differ from each other. Overall, the findings from this study suggest that the final phenotype are strongly influenced by the polymorphisms found in MEN, the interactions between genetic background and environmental conditions.Master of Science (MSc) in Chemical Science

Codes of ethics in Sweden\u27s largest public sector organizations : communicating the intent of the code within the organization

The aim of the study was to examine the ways that public sector organizations in Sweden communicated the intent of their codes of ethics to their employees. Primary data was obtained via a self-administered mail questionnaire distributed to a census of the top 100 organizations. The study identified a range of methods used by organizations to integrate the ethos of codes into corporate culture. These methods included communication of the code, company induction of new staff, consequences for a breach of the code, ethical performance, an ethics ombudsman, the support of whistleblowers, a standing ethics committee, ethics education, and an ethics education committee.Whilst many organizations have instituted ethical behaviour initiatives, activities specifically targeted at exposure, education and support for staff to perform ethically were found to be underdeveloped.<br /

COSMOLOGICAL ORIGIN OF QUASARS

Quasars are the earliest objects known to exist. We examine their origin in the context of popular models for structure formation in the universe. We show that seeds for quasar black holes could have originated from the initial cosmological collapse of overdense regions with unusually small rotation. Most of these seeds have a mass of order 10^6 solar masses, just above the cosmological Jeans mass. For Cold Dark Matter cosmologies, we find of order one seed black hole per bright galaxy. After the galaxy forms, the seeds inside its bulge sink to the center by dynamical friction. We also describe a few empirical methods to study the properties of quasars and their environments. These include: probing quasar hosts through [C II] emission, finding quasar lifetimes from the ``proximity effect'' along two lines of sight, and measuring the amplitude of clustering at high redshifts through the detection of Lyman-alpha clouds beyond the quasar redshift.Comment: 5 pages, Standard Tex, contribution to the Texas symposium in Munich, Dec. 1994

Access Time Minimization in IEEE 1687 Networks

IEEE 1687 enables flexible access to the embedded (on-chip) instruments that are needed for post-silicon validation, debugging, wafer sort, package test, burn-in, printed circuit board bring-up, printed circuit board assembly manufacturing test, power-on self-test, and in-field test. At any of these scenarios, the instruments are accessed differently, and at a given scenario the instruments are accessed differently over time. It means the IEEE 1687 network needs to be frequently reconfigured from accessing one set of instruments to accessing a different set of instruments. Due to the need of frequent reconfiguration of the IEEE 1687 network it is important to (1) minimize the run-time for the algorithm finding the new reconfiguration, and (2) generate scan vectors with minimized access time. In this paper we model the reconfiguration problem using Boolean Satisfiability Problem (SAT). Compared to previous works we show significant reduction in run-time and we ensure minimal access time for the generated scan vectors

Microbial characterization of a mine soil subjected to different remediation technologies combining organic and inorganic treatments and plant cultivation

RAMIRAN International ConferenceIn Portugal, additional research is needed if technologies based on the combined action of plants and the microbial communities they support within the rhizosphere are to be adopted in large-scale remediation actions (Nabais et al., 2008). Plants growing in abandoned mines are useful to indicate the mineral composition of the soil and they are able to accumulate or exclude toxic metals (Pratas et al., 2005). Taking into account that the mine degraded soils have low concentrations of plant nutrients, it is necessary to apply amendments to ensure plant cover when remediation technologies are present. But soil amendments and the development of a root system might induce shifts in the microbial community structure among the different treatments (Pérez-de-Mora et al., 2006). Moreover, data about the toxic effects of heavy metals on soil microorganisms indicated that heavy metal-sensitive bacteria are probably responsible for the decrease in bacterial activity and the competitive advantage of more tolerant ones resulted in a change in community composition (Díaz-Raviña and Bååth, 1996). Hence, relationships between the soil composition, plant species occurring above-ground and the soil microbial communities have been revealed in many research (Kourtev et al., 2003) providing an important link between above and below-ground processes in terrestrial ecosystems. Soil microbial community structure is increasingly being marketed as ecologically-relevant endpoint and it can realistically be incorporated for assessing the potential risks associated with soil amendment strategies on sustainability of soil ecosystems. Studies of different remediation technologies with mine soils in Portugal, including amendment materials from farming and industrial sources and the use of native plant species (Guiwei et al., 2008; de Varennes et al., 2009) revealed differential effects of treatments on soil enzymes and microbial respiration, suggesting a change in microbial communities. The information about this fact is scarce and had focused on soil biochemical properties, producing no clear results. Phospholipid fatty acid (PLFA) patterns are sensitive indicators of changes in microbial community structure. This technique has been used to elucidate different strategies employed by microorganism to adapt to changed environmental conditions under wide ranges of soil types, management practices, climatic origins and different perturbations (Zelles, 1999). The present study is the first attempt to characterize, by means of the analysis of PLFA patterns, soil microbial population from a Pb-contaminated mine soil subjected to different remediation technologies including revegetation with native herbaceous species

Microbial community structure in a unlimed and limed mine contaminated soil (Pb, Cu, As) with different organic and inorganic treatments

RAMIRAN International ConferenceMine contaminated soils are very unfavourable environments with limiting factors, in particular residual high levels of heavy metals, soil acidity, lack of organic matter and poor substrate structure. Toxic effects of HM on soil microorganisms have been extensively studied (Frostegård et al., 1993; Bååth et al., 1998) and the measurements of community structure indicated that the HM had an effect resulting in a change in community composition (Ellis et al., 2003; Rajapaksha et al, 2004). Nowadays molecular biology techniques, such as the analysis of phospholipid fatty acid (PLFA) patterns, make it possible to study the microbial community structure of soil microorganisms. The PLFA technique has been used to elucidate different strategies employed by microorganism to adapt to changed environmental conditions under wide ranges of soil types, management practices, climatic origins and different perturbations (Zelles, 1999). By phospholipid fatty acid analysis it is possible to examine broad scale patterns in microbial community structure (Bååth et al. 2005) and generally, after the application of multivariate statistical analyses, whole community fatty acids profiles indicate which communities are similar or different. Determination both microbial community composition and biomass size by this direct method gives results that very closely represent the in situ soil conditions and is currently used for soil monitoring purposes (Nielsen and Winding, 2002). This study aimed to evaluate the effect of different remediation technologies in a mine contaminated soil including several organic and inorganic treatments combined with liming by the soil microbial community structure analysi

Evaluating capabilities of novel warm-season crops to fill forage deficit periods in the Southern Great Plains

Low nutritive value of perennial grasses during mid-late summer limits stocker cattle production in the Southern Great Plains (SGP). Our objectives were to explore annual crop species that might fit as a summer forage, and quantify their forage potentials under the highly variable agro-climatic conditions of the SGP. A field experiment compared the seasonal changes in aboveground dry matter (ADM), leaf-to-stem ratio, and chemical composition of tepary bean (Phaseolus acutifolius) and guar (Cyamopsis tetragonoloba) to soybean (Glycine max). Tepary bean outperformed soybean and guar by producing greater ADM (6.5 Mg ha-1) with a leaf-to-stem ratio of 3.1 at 65 days after planting (DAP), and its chemical composition also remained superior and consistent throughout the growing season. Secondly, ten mothbean (Vigna aconitifolia) lines were evaluated for their forage, grain or green manure potentials. Mothbean lines generated a ADM range of 7.3-18.1 Mg ha-1 with 10.8-14.6% crude protein (CP), 32.0-41.7% neutral detergent fiber (NDF), 20.7-29.6% acid detergent fiber (ADF), and 73-84% in vitro true digestibility (IVTD) at 100 DAP. Third, eleven finger millet (Eleusine coracana) accessions were assessed for their adaptability and forage characterization under the SGP conditions. Finger millet accessions resulted in ADM ranging from 5.0-12.3 Mg ha-1, which contained 10.5-15.6% CP, 59.8-73.4% NDF, 26.8-38.2% ADF, and 59.7-73.0% IVTD at 165 DAP. Finally, a greenhouse study was conducted to compare vegetative growth and physiological responses of mothbean, tepary and guar under four different water regimes. Tepary bean showed the lowest stomatal conductance (gs) and photosynthetic rate (A), but it maintained the highest instantaneous water use efficiency (WUEi) among species under water-stressed treatments. At final harvest (77 DAP), the ADM generated by tepary bean was 38-60% and 41-56% higher than guar and mothbean, respectively, across four water deficits. Tepary bean was identified as the most drought-tolerant and reliable option for SGP among the tested species, considering its higher biomass production, WUEi, leaf-to-stem ratio, and consistent nutritive value when grown as a summer forage. Future research should focus on defining management practices for growing these novel crops in extensive production settings for grazing or hay

Spins of the supermassive black hole in M87: new constraints from TeV observations

The rapid TeV $\gamma-$ray variability detected in the well-known nearby radio galaxy M87 implies an extremely compact emission region (5-10 Schwarzschild radii) near the horizon of the supermassive black hole in the galactic center. TeV photons are affected by dilution due to interaction with the radiation field of the advection-dominated accretion flow (ADAF) around the black hole, and can thus be used to probe the innermost regions around the black hole. We calculate the optical depth of the ADAF radiation field to the TeV photons and find it strongly depends on the spin of the black hole. We find that transparent radii of 10 TeV photons are of $5R_{\rm S}$ and $13R_{\rm S}$ for the maximally rotating and non-rotating black holes, respectively. With the observations, the calculated transparent radii strongly suggest the black hole is spinning fast in the galaxy. TeV photons could be used as a powerful diagnostic for estimating black hole spins in galaxies in the future.Comment: 4 pages, 4 figures. to appear in ApJ