Tandemly repeated C-C-C-C-A-A hexanucleotide of Tetrahymena rDNA is present elsewhere in the genome and may be related to the alteration of the somatic genome.

The ribosomal RNA genes of the Tetrahymena macronucleus exist as extrachromosomal, linear molecules. The termini of these molecules have been shown to contain the tandemly repeated hexanucleotide (C-C-C-C-A-A)n. In this study the same or related sequences were found in other locations of the genome. Using the depurination method, we showed that macronuclear DNA contained this sequence even after rDNA had been removed. The sequence was found mainly in the repetitive fraction of the DNA. The presence of this sequence in both the macronucleus and the micronucleus was also shown by Southern hybridization using C-C-C-C-A-A repeat as a probe. Comparison between the hybridization patterns of macronuclei and micronuclei reveals interesting differences. Whereas the two nuclei share the same genetic origin, the majority of the restriction enzyme digestion sites flanking the C-C-C-C-A-A repeat appear to be different. Such a difference was found to be specific for this sequence, because it was not detected when other sequences were used for hybridization. These results suggest that some kind of alteration has occurred in the genome during the formation of the macronucleus, and that the C-C-C-C-A-A repeat may be related to this process

Applying the expanding photosphere and standardized candle methods to Type II-Plateau supernovae at cosmologically significant redshifts: the distance to SN 2013eq

Based on optical imaging and spectroscopy of the Type II-Plateau SN 2013eq, we present a comparative study of commonly used distance determination methods based on Type II supernovae. The occurrence of SN 2013eq in the Hubble flow (z = 0.041 +/- 0.001) prompted us to investigate the implications of the difference between "angular" and "luminosity" distances within the framework of the expanding photosphere method (EPM) that relies upon a relation between flux and angular size to yield a distance. Following a re-derivation of the basic equations of the EPM for SNe at non-negligible redshifts, we conclude that the EPM results in an angular distance. The observed flux should be converted into the SN rest frame and the angular size, theta, has to be corrected by a factor of (1+z)^2. Alternatively, the EPM angular distance can be converted to a luminosity distance by implementing a modification of the angular size. For SN 2013eq, we find EPM luminosity distances of D_L = 151 +/- 18 Mpc and D_L = 164 +/- 20 Mpc by making use of different sets of dilution factors taken from the literature. Application of the standardized candle method for Type II-P SNe results in an independent luminosity distance estimate (D_L = 168 +/- 16 Mpc) that is consistent with the EPM estimate.Comment: 12 pages, 4 figures, accepted by A&

Match injuries in professional soccer: inter-seasonal variation and effects of competition type, match congestion and positional role

In this prospective observational study, injuries sustained in official match-play in players belonging to a professional soccer club were investigated. Incidence and patterns of injury were compared across four-seasons (2005-2006: S1, 2006-2007: S2, 2007-2008: S3 and 2008-2009: S4) and 3 match formats (domestic League/Cup games and European club competition). In addition, the effects of both fixture congestion and the positional role of players were investigated. Injury incidence (per 1 000 match-hours) did not vary between seasons (range 31.2-59.2 observed in S2 and S4, respectively, p=0.12) or fixture formats (range 32.6-40.8 observed in European and League matches, respectively, p=0.49). In contrast, rates varied in players (n=7) who participated in all four seasons as more injuries were sustained in S1 compared to S2 and S3, respectively (88.4 vs. 49.0 vs. 49.2, both p or = 4 days). Finally, the incidence of injury and muscle strains (both p<0.001) varied across positional roles with the highest rates observed in centre-forwards. These findings provide further knowledge on the risk of injury in contemporary professional soccer match-play and may aid in the care and management of playing resources

Effect of diet and atmosphere on intestinal and skin flora. Volume II - Literature survey

Literature survey and experimental observations of human skin microflora, including study of men confined in simulated spacecraft environmen

Influence of physical and biological oceanography on the structure of the seabird community in the northeastern Chukchi Sea

Thesis (Ph.D.) University of Alaska Fairbanks, 2015The Chukchi Sea is losing seasonal ice cover as global temperatures rise, facilitating human access to the region for activities such as oil and gas exploration, shipping, and tourism. Processes and responses to environmental change by marine ecosystems are often challenging to quantify because they are hidden under water. Seabirds, however, offer visible evidence of the health and status of marine ecosystems. I studied the community structure, variability in abundance and distribution, and habitat associations of seabirds in the eastern Chukchi Sea. My results provide insights into the influence of climate change on seabirds and a benchmark against which to evaluate possible impacts of anthropogenic activity. Repeated sampling of systematic transects in the northeastern Chukchi Sea during the ice-free seasons of 2008-2012 showed that the community consisted of ~40 species and was dominated numerically by planktivorous seabirds, particularly Crested Auklets (Aethia cristatella) and Short-tailed Shearwaters (Puffinus tenuirostris). In contrast, benthic-feeding birds were rare. The abundance of seabirds in the offshore northeastern Chukchi Sea varied by up to two orders of magnitude among years and birds generally were more abundant in September than August. Despite these seasonal and interannual variations in abundance, the species composition was similar among years, with anomalies occurring only in years of persistent ice cover. I compared data from this recent period (2008-2012) with data from historical surveys (1975-1981) to evaluate decadal trends in seabird abundance and composition and related those changes to reductions in seasonal ice cover. The seabird community shifted from one consisting primarily of piscivorous seabirds to one consisting primarily of planktivorous seabirds. This shift suggests that zooplankton prey are more accessible now to avian predators as seasonal ice cover has declined. I explored the relationships between seabirds, hydrography, and zooplankton abundance with spatially explicit generalized additive models. The associations of seabirds with habitat characteristics varied with foraging method and preferred prey. Species that fed primarily by pursuit diving were more abundant in warm, weakly stratified water, whereas surface-feeding species were more abundant in cold, strongly stratified water. Planktivorous seabirds (auklets, shearwaters, and phalaropes) were more abundant within 20 km of thermal surface fronts and in contrast, omnivores (gulls and murres) were more abundant far from thermal fronts. For 5 of the 8 seabird species, information about prey biomass improved predictions of seabird abundance, although the relationships were not as clear as they were for the physical habitat characteristics indicative of processes that aggregate prey. Advective processes that transport oceanic species of zooplankton from the Bering Sea to the Chukchi Sea, together with the local influence of sea ice on physical and biological processes, strongly influence the distribution of seabirds, particularly the planktivorous species. Scientists and decision-makers can use the results of this multi-species and multi-disciplinary study as a benchmark to assess the ecological consequences of anthropogenic activity against the backdrop of climate change that is affecting the Chukchi Sea

Crossover from Endogenous to Exogenous Activity in Open-Source Software Development

We have investigated the origin of fluctuations in the aggregated behaviour of an open-source software community. In a recent series of papers, de Menezes and co-workers have shown how to separate internal dynamics from external fluctuations by capturing the simultaneous activity of many system's components. In spite of software development being a planned activity, the analysis of fluctuations reveals how external driving forces can be only observed at weekly and higher time scales. Hourly and higher change frequencies mostly relate to internal maintenance activities. There is a crossover from endogenous to exogenous activity depending on the average number of file changes. This new evidence suggests that software development is a non-homogeneous design activity where stronger efforts focus in a few project files. The crossover can be explained with a Langevin equation associated to the cascading process, where changes to any file trigger additional changes to its neighbours in the software network. In addition, analysis of fluctuations enables us to detect whether a software system can be decomposed in several subsystems with different development dynamics.Comment: 7 pages, 4 figures, submitted to Europhysics Letter

Faiblesse de l’effort français pour la recherche dans le domaine de l’Agriculture Biologique : approche scientométrique

La France est la première puissance agricole européenne et le troisième marché pour l'alimentation biologique. Pourtant elle ne se situe qu'au 25ème rang mondial en terme de pourcentage de la surface agricole consacrée à l'agriculture biologique, et importe plus de la moitié de sa consommation. Un fort développement de la recherche en ce domaine est réclamé par les associations afin de répondre aux défis écologiques, économiques, énergétiques et sociaux posés à l'agriculture du XXIème siècle. Quelle est exactement la place consacrée à l’agriculture biologique dans la recherche agronomique des différents pays européens ? La reconnaissance de la pertinence de l’agriculture biologique comme domaine de recherche par l'INRA depuis 1999 a-t-elle conduit à une meilleure priorisation de la recherche en agriculture biologique ? Une analyse bibliométrique par mots-clés des publications scientifiques recensées dans la base de données ISI Web of Science de Thomson Scientific permet de construire des indicateurs suffisamment pertinents pour une comparaison des efforts de recherche nationaux sur la période 2000-2006, et ainsi de juger du niveau de priorisation réel de la recherche en agriculture biologique. Les résultats obtenus confirment le retard de la France, et sont à mettre en relation avec le manque de soutien institutionnel, de moyens humains et financiers consacrés à l’agriculture biologique au sein des organismes en charge de la recherche agronomique française, et ce, malgré les ambitions affichées

Infliximab for the treatment of plaque psoriasis

Infliximab is a monoclonal antibody that targets tumor necrosis factor-α (TNFα). It is used in the treatment of a number of inflammatory disorders including severe plaque psoriasis. TNFα is thought to have a major role in psoriasis by promoting an inflammatory infiltrate into the skin and inducing keratinocyte proliferation and preventing keratinocyte apoptosis, which directly contributes to the characteristic plaque skin lesions. Based on four randomized, placebo-controlled, double-blind clinical trials and nine open-label uncontrolled trials of the use of infliximab in plaque psoriasis, it was found that infliximab is a highly efficacious, rapid, sustainable, and relatively safe therapy. Yet as with any biologic, caution is recommended in its use as infusion reactions, lupus-like syndromes, infections, malignancies including lymphomas, as well as other rare events have been reported