421 research outputs found
Nonlinearities and Effects of Transverse Beam Size in Beam Position Monitors (revised)
The fields produced by a long beam with a given transverse charge
distribution in a homogeneous vacuum chamber are studied. Signals induced by a
displaced finite-size beam on electrodes of a beam position monitor (BPM) are
calculated and compared to those produced by a pencil beam. The non-linearities
and corrections to BPM signals due to a finite transverse beam size are
calculated for an arbitrary chamber cross section. Simple analytical
expressions are given for a few particular transverse distributions of the beam
current in a circular or rectangular chamber. Of particular interest is a
general proof that in an arbitrary homogeneous chamber the beam-size
corrections vanish for any axisymmetric beam current distribution.Comment: REVTeX, 8 pages, 9 figures. Corrected Eqs. (7),(22),(25) and Figs.
2-9. Expande
Quantitative principles of cis-translational control by general mRNA sequence features in eukaryotes.
BackgroundGeneral translational cis-elements are present in the mRNAs of all genes and affect the recruitment, assembly, and progress of preinitiation complexes and the ribosome under many physiological states. These elements include mRNA folding, upstream open reading frames, specific nucleotides flanking the initiating AUG codon, protein coding sequence length, and codon usage. The quantitative contributions of these sequence features and how and why they coordinate to control translation rates are not well understood.ResultsHere, we show that these sequence features specify 42-81% of the variance in translation rates in Saccharomyces cerevisiae, Schizosaccharomyces pombe, Arabidopsis thaliana, Mus musculus, and Homo sapiens. We establish that control by RNA secondary structure is chiefly mediated by highly folded 25-60 nucleotide segments within mRNA 5' regions, that changes in tri-nucleotide frequencies between highly and poorly translated 5' regions are correlated between all species, and that control by distinct biochemical processes is extensively correlated as is regulation by a single process acting in different parts of the same mRNA.ConclusionsOur work shows that general features control a much larger fraction of the variance in translation rates than previously realized. We provide a more detailed and accurate understanding of the aspects of RNA structure that directs translation in diverse eukaryotes. In addition, we note that the strongly correlated regulation between and within cis-control features will cause more even densities of translational complexes along each mRNA and therefore more efficient use of the translation machinery by the cell
Cost of hospitalised patients due to complicated urinary tract infections: a retrospective observational study in countries with high prevalence of multidrug-resistant Gram-negative bacteria: the COMBACTE-MAGNET, RESCUING study
OBJECTIVE: Complicated urinary tract infections (cUTIs) impose a high burden on healthcare systems and are a frequent cause of hospitalisation. The aims of this paper are to estimate the cost per episode of patients hospitalised due to cUTI and to explore the factors associated with cUTI-related healthcare costs in eight countries with high prevalence of multidrug resistance (MDR). DESIGN: This is a multinational observational, retrospective study. The mean cost per episode was computed by multiplying the volume of healthcare use for each patient by the unit cost of each item of care and summing across all components. Costs were measured from the hospital perspective. Patient-level regression analyses were used to identify the factors explaining variation in cUTI-related costs. SETTING: The study was conducted in 20 hospitals in eight countries with high prevalence of multidrug resistant Gram-negative bacteria (Bulgaria, Greece, Hungary, Israel, Italy, Romania, Spain and Turkey). PARTICIPANTS: Data were obtained from 644 episodes of patients hospitalised due to cUTI. RESULTS: The mean cost per case was €5700, with considerable variation between countries (largest value €7740 in Turkey; lowest value €4028 in Israel), mainly due to differences in length of hospital stay. Factors associated with higher costs per patient were: type of admission, infection source, infection severity, the Charlson comorbidity index and presence of MDR. CONCLUSIONS: The mean cost per hospitalised case of cUTI was substantial and varied significantly between countries. A better knowledge of the reasons for variations in length of stays could facilitate a better standardised quality of care for patients with cUTI and allow a more efficient allocation of healthcare resources. Urgent admissions, infections due to an indwelling urinary catheterisation, resulting in septic shock or severe sepsis, in patients with comorbidities and presenting MDR were related to a higher cost
A systematic review assessing non-pharmacological conservative treatment studies for people with non-inflammatory multi-joint pain: clinical outcomes and research design considerations
To systematically review the evidence to determine the clinical outcomes and the important methodological quality features of interventional studies on adults with non-inflammatory multi-joint pain (MJP). Systematic search of published and unpublished literature using the databases: AMED, CINAHL, MEDLINE, EMBASE, psycINFO, SPORTDiscus, PEDro, OpenGrey, the EU Clinical Trials Register, World Health Organization International Clinical Trial Registry Platform, ClinicalTrials.gov and the ISRCTN registry (search: inception to 19th October 2017). All papers reporting the clinical outcomes of non-pharmacological interventions for people with non-inflammatory MJP were included. Studies were critically appraised using the Downs and Black Critical Appraisal and the TIDieR reporting checklists. Data were analysed using a Best Evidence Synthesis approach. From 3824 citations, four papers satisfied the eligibility criteria. Three studies reported outcomes from multidisciplinary rehabilitation programmes and one study reported the findings of a spa therapy intervention. All interventions significantly improved pain, function and quality of life in the short-term. There was limited reporting of measures for absenteeism, presenteeism and psychosocial outcomes. The evidence was ‘weak’, and due to a lack of controlled trials, there is limited evidence to ascertain treatment effectiveness. Design consideration for future trials surround improved reporting of participant characteristics, interventions and the standardisation of core outcome measures. There is insufficient high-quality trial data to determine the effectiveness of treatments for non-inflammatory MJP. Given the significant health burden which this condition presents on both individuals and wider society, developing and testing interventions and accurately reporting these, should be a research priority
Bedrijfseconomische perspectieven van akkerbouwbedrijven in de Veenkolonien
In het onderzoek is getracht een indruk te krijgen omtrent de perspectieven van de akkerbouw in de Veenkolonien bij een zuiver akkerbouwmatige exploitatie van de bedrijven. Braaklegging is ook als teeltmogelijkheid opgevoerd, terwijl de houtteelt buiten beschouwing is gelate
Bedrijfseconomische perspectieven voor akkerbouwbedrijven in de Veenkolonien = Financial perspectives of arable farms in the district Veenkolonien
Bij de bedrijfseconomische berekeningen is braaklegging ook als teeltmogelijkheid opgevoer
AvBD1 nucleotide polymorphisms, peptide antimicrobial activities and microbial colonisation of the broiler chicken gut
Abstract Background The importance of poultry as a global source of protein underpins the chicken genome and associated SNP data as key tools in selecting and breeding healthy robust birds with improved disease resistance. SNPs affecting host peptides involved in the innate defences tend to be rare, but three non-synonymous SNPs in the avian β-defensin (AvBD1) gene encoding the variant peptides NYH, SSY and NYY were identified that segregated specifically to three lines of commercial broiler chickens Line X (LX), Line Y(LY) and Line Z. The impacts of such amino acid changes on peptide antimicrobial properties were analysed in vitro and described in relation to the caecal microbiota and gut health of LX and LY birds. Results Time-kill and radial immune diffusion assays indicated all three peptides to have antimicrobial properties against gram negative and positive bacteria with a hierarchy of NYH > SSY > NYY. Calcein leakage assays supported AvBD1 NYH as the most potent membrane permeabilising agent although no significant differences in secondary structure were identified to explain this. However, distinct claw regions, identified by 3D modelling and proposed to play a key role in microbial membrane attachment, and permeation, were more distinct in the NYH model. In vivo AvBD1 synthesis was detected in the bird gut epithelia. Analyses of the caecal gut microbiota of young day 4 birds suggested trends in Lactobacilli sp. colonisation at days 4 (9% LX vs × 30% LY) and 28 (20% LX vs 12% LY) respectively, but these were not statistically significant (P > 0.05). Conclusion Amino acid changes altering the killing capacity of the AvBD1 peptide were associated with two different bird lines, but such changes did not impact significantly on caecal gut microbiota
The potential for immunoglobulins and host defense peptides (HDPs) to reduce the use of antibiotics in animal production
Abstract Innate defense mechanisms are aimed at quickly containing and removing infectious microorganisms and involve local stromal and immune cell activation, neutrophil recruitment and activation and the induction of host defense peptides (defensins and cathelicidins), acute phase proteins and complement activation. As an alternative to antibiotics, innate immune mechanisms are highly relevant as they offer rapid general ways to, at least partially, protect against infections and enable the build-up of a sufficient adaptive immune response. This review describes two classes of promising alternatives to antibiotics based on components of the innate host defense. First we describe immunoglobulins applied to mimic the way in which they work in the newborn as locally acting broadly active defense molecules enforcing innate immunity barriers. Secondly, the potential of host defense peptides with different modes of action, used directly, induced in situ or used as vaccine adjuvants is described
De bedrijfsgrootte voor akkerbouwbedrijven in het Centraal Kleigebied = Farm size of arable farming in the central clay district
Het doel van het onderzoek is om na te gaan welke bedrijfsgrootte op termijn nodig is om de ondernemer een redelijke arbeidsbeloning te verschaffen nu de overheid een stringenter milieubeleid hanteert en de subsidies afnemen. Het onderzoek is uitgevoerd met behulp van gemengd geheeltallige lineaire programmerin
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