959 research outputs found

    Characterizations of how species mediate ecosystem properties require more comprehensive functional effect descriptors

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    The importance of individual species in mediating ecosystem process and functioning is generally accepted, but categorical descriptors that summarize species-specific contributions to ecosystems tend to reference a limited number of biological traits and underestimate the importance of how organisms interact with their environment. Here, we show how three functionally contrasting sediment-dwelling marine invertebrates affect fluid and particle transport - important processes in mediating nutrient cycling - and use high-resolution reconstructions of burrow geometry to determine the extent and nature of biogenic modification. We find that individual functional effect descriptors fall short of being able to adequately characterize how species mediate the stocks and flows of important ecosystem properties and that, in contrary to common practice and understanding, they are not substitutable with one another because they emphasize different aspects of species activity and behavior. When information derived from these metrics is combined with knowledge of how species behave and modify their environment, however, detailed mechanistic information emerges that increases the likelihood that a species functional standing will be appropriately summarized. Our study provides evidence that more comprehensive functional effect descriptors are required if they are to be of value to those tasked with projecting how altered biodiversity will influence future ecosystems

    Competing mortality in patients diagnosed with bladder cancer: evidence of undertreatment in the elderly and female patients

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    Background: Bladder cancer (BC) predominantly affects the elderly and is often the cause of death among patients with muscleinvasive disease. Clinicians lack quantitative estimates of competing mortality risks when considering treatments for BC. Our aim was to determine the bladder cancer-specific mortality (CSM) rate and other-cause mortality (OCM) rate for patients with newly diagnosed BC. Methods: Patients (n ¼ 3281) identified from a population-based cancer registry diagnosed between 1994 and 2009. Median follow-up was 48.15 months (IQ range 18.1–98.7). Competing risk analysis was performed within patient groups and outcomes compared using Gray’s test. Results: At 5 years after diagnosis, 1246 (40%) patients were dead: 617 (19%) from BC and 629 (19%) from other causes. The 5-year BC mortality rate varied between 1 and 59%, and OCM rate between 6 and 90%, depending primarily on the tumour type and patient age. Cancer-specific mortality was highest in the oldest patient groups. Few elderly patients received radical treatment for invasive cancer (52% vs 12% for patients o60 vs 480 years, respectively). Female patients with high-risk non-muscle-invasive BC had worse CSM than equivalent males (Gray’s Po0.01). Conclusion: Bladder CSM is highest among the elderly. Female patients with high-risk tumours are more likely to die of their disease compared with male patients. Clinicians should consider offering more aggressive treatment interventions among older patients

    Evolutionary Sequence Modeling for Discovery of Peptide Hormones

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    There are currently a large number of “orphan” G-protein-coupled receptors (GPCRs) whose endogenous ligands (peptide hormones) are unknown. Identification of these peptide hormones is a difficult and important problem. We describe a computational framework that models spatial structure along the genomic sequence simultaneously with the temporal evolutionary path structure across species and show how such models can be used to discover new functional molecules, in particular peptide hormones, via cross-genomic sequence comparisons. The computational framework incorporates a priori high-level knowledge of structural and evolutionary constraints into a hierarchical grammar of evolutionary probabilistic models. This computational method was used for identifying novel prohormones and the processed peptide sites by producing sequence alignments across many species at the functional-element level. Experimental results with an initial implementation of the algorithm were used to identify potential prohormones by comparing the human and non-human proteins in the Swiss-Prot database of known annotated proteins. In this proof of concept, we identified 45 out of 54 prohormones with only 44 false positives. The comparison of known and hypothetical human and mouse proteins resulted in the identification of a novel putative prohormone with at least four potential neuropeptides. Finally, in order to validate the computational methodology, we present the basic molecular biological characterization of the novel putative peptide hormone, including its identification and regional localization in the brain. This species comparison, HMM-based computational approach succeeded in identifying a previously undiscovered neuropeptide from whole genome protein sequences. This novel putative peptide hormone is found in discreet brain regions as well as other organs. The success of this approach will have a great impact on our understanding of GPCRs and associated pathways and help to identify new targets for drug development

    Measurement of B(t->Wb)/B(t->Wq) at the Collider Detector at Fermilab

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    We present a measurement of the ratio of top-quark branching fractions R= B(t -> Wb)/B(t -> Wq), where q can be a b, s or a d quark, using lepton-plus-jets and dilepton data sets with integrated luminosity of ~162 pb^{-1} collected with the Collider Detector at Fermilab during Run II of the Tevatron. The measurement is derived from the relative numbers of t-tbar events with different multiplicity of identified secondary vertices. We set a lower limit of R > 0.61 at 95% confidence level.Comment: 7 pages, 2 figures, published in Physical Review Letters; changes made to be consistent with published versio

    Potential process 'hurdles' in the use of macroalgae as feedstock for biofuel production in the British Isles

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    This review examines the potential technical and energy balance hurdles in the production of seaweed biofuel, and particular for the MacroBioCrude processing pipeline for the sustainable manufacture of liquid hydrocarbon fuels from seaweed in the UK. The production of biofuel from seaweed is economically, energetically and technically challenging at scale. Any successful process appears to require both a method of preserving the seaweed for continuous feedstock availability and a method exploiting the entire biomass. Ensiling and gasification offer a potential solution to these two requirements. However there is need for more data particularly at a commercial scal

    A Study of B0 -> J/psi K(*)0 pi+ pi- Decays with the Collider Detector at Fermilab

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    We report a study of the decays B0 -> J/psi K(*)0 pi+ pi-, which involve the creation of a u u-bar or d d-bar quark pair in addition to a b-bar -> c-bar(c s-bar) decay. The data sample consists of 110 1/pb of p p-bar collisions at sqrt{s} = 1.8 TeV collected by the CDF detector at the Fermilab Tevatron collider during 1992-1995. We measure the branching ratios to be BR(B0 -> J/psi K*0 pi+ pi-) = (8.0 +- 2.2 +- 1.5) * 10^{-4} and BR(B0 -> J/psi K0 pi+ pi-) = (1.1 +- 0.4 +- 0.2) * 10^{-3}. Contributions to these decays are seen from psi(2S) K(*)0, J/psi K0 rho0, J/psi K*+ pi-, and J/psi K1(1270)

    Search for ZZ and ZW Production in ppbar Collisions at sqrt(s) = 1.96 TeV

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    We present a search for ZZ and ZW vector boson pair production in ppbar collisions at sqrt(s) = 1.96 TeV using the leptonic decay channels ZZ --> ll nu nu, ZZ --> l l l' l' and ZW --> l l l' nu. In a data sample corresponding to an integrated luminosity of 194 pb-1 collected with the Collider Detector at Fermilab, 3 candidate events are found with an expected background of 1.0 +/- 0.2 events. We set a 95% confidence level upper limit of 15.2 pb on the cross section for ZZ plus ZW production, compared to the standard model prediction of 5.0 +/- 0.4 pb.Comment: 7 pages, 2 figures. This version is accepted for publication by Phys. Rev. D Rapid Communication

    Measurement of the Cross Section for Prompt Diphoton Production in p-pbar Collisions at sqrt(s) = 1.96 TeV

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    We report a measurement of the rate of prompt diphoton production in ppˉp\bar{p} collisions at s=1.96 TeV\sqrt{s}=1.96 ~\hbox{TeV} using a data sample of 207 pb1^{-1} collected with the upgraded Collider Detector at Fermilab (CDF II). The background from non-prompt sources is determined using a statistical method based on differences in the electromagnetic showers. The cross section is measured as a function of the diphoton mass, the transverse momentum of the diphoton system, and the azimuthal angle between the two photons and is found to be consistent with perturbative QCD predictions.Comment: 7 pages, 3 figures,revtex4. Version accepted by PRL, but with cross section tables i

    Measurement of CP-violation asymmetries in D0 to Ks pi+ pi-

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    We report a measurement of time-integrated CP-violation asymmetries in the resonant substructure of the three-body decay D0 to Ks pi+ pi- using CDF II data corresponding to 6.0 invfb of integrated luminosity from Tevatron ppbar collisions at sqrt(s) = 1.96 TeV. The charm mesons used in this analysis come from D*+(2010) to D0 pi+ and D*-(2010) to D0bar pi-, where the production flavor of the charm meson is determined by the charge of the accompanying pion. We apply a Dalitz-amplitude analysis for the description of the dynamic decay structure and use two complementary approaches, namely a full Dalitz-plot fit employing the isobar model for the contributing resonances and a model-independent bin-by-bin comparison of the D0 and D0bar Dalitz plots. We find no CP-violation effects and measure an asymmetry of ACP = (-0.05 +- 0.57 (stat) +- 0.54 (syst))% for the overall integrated CP-violation asymmetry, consistent with the standard model prediction.Comment: 15 page

    Hospital contacts for injuries and musculoskeletal diseases among seamen and fishermen: A population-based cohort study

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    <p>Abstract</p> <p>Background</p> <p>We studied musculoskeletal diseases (MSD) and injuries among fishermen and seamen with focus on low back disorders, carpal tunnel syndrome (CTS), rotator cuff syndrome and arthrosis.</p> <p>Methods</p> <p>Cohorts of all male Danish seamen (officers and non-officers) and fishermen employed 1994 and 1999 with at least six months employment history were linked to the Occupational Hospitalisation Register. We calculated standardised incidence ratios (SIR) for the two time periods, using rates for the entire Danish workforce as a reference.</p> <p>Results</p> <p>Among fishermen, we found high SIRs for knee arthrosis, thoraco-lumbar disc disorders, injuries and statistically significant SIRs above 200 were seen for both rotator cuff syndrome and CTS. The SIR was augmented for injuries and reduced for hip arthrosis between the two time periods. The SIRs for injuries and CTS were high for non-officers. A sub-analysis revealed that the highest risk for CTS was found among male non-officers working as deck crew, SIR 233 (95% CI: 166–317) based on 40 cases. Among officers, the SIRs for injuries and MSDs were low. The number of employed Danish fishermen declined with 25% 1994–1999 to 3470. Short-term employments were common. None of the SIRs increased with increasing length of employment.</p> <p>Conclusion</p> <p>Both fishermen and non-officers have high SIRs for injuries and fishermen also for MSD. Only the SIR for injuries among fishermen was augmented between 1994 and 1999. Our findings suggest an association between the incidence of rotator cuff syndrome and CTS and work within fishery. Long-term cumulative effects of employment were not shown for any of the disease outcomes. Other conditions may play a role.</p
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