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Strange matter is believed to exist in the cores of neutron stars based on simple kinematics. If this is true, then hyperon-nucleon interactions will play a significant part in the neutron star equation of state. Yet, compared to other elastic scattering processes, there is very little data on Λ-N scattering. This experiment utilized the CEBAF Large Acceptance Spectrometer (CLAS) detector to study the ΛpâΛp elastic scattering cross section in the incident Λ momentum range 0.9-2.0 GeV/c. These are the first data on this reaction since the 1970s. The new cross sections have significantly better accuracy and precision than the existing world data, and the techniques developed here can also be used in future experiments.
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In an emulsion-counter hybrid experiment performed at J-PARC, a Ξ^{-} absorption event was observed which decayed into twin single-Λ hypernuclei. Kinematic calculations enabled a unique identification of the reaction process as Ξ^{-}+^{14}Nâ_{Λ}^{10}Be+_{Λ}^{5}He. For the binding energy of the Ξ^{-} hyperon in the Ξ^{-}-^{14}N system a value of 1.27±0.21 MeV was deduced. The energy level of Ξ^{-} is likely a nuclear 1p state which indicates a weak ΞN-ΛΛ coupling.
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The quark structure of the f_{2}(1270) meson has, for many years, been assumed to be a pure quark-antiquark (qq[over ¯]) resonance with quantum numbers J^{PC}=2^{++}. Recently, it was proposed that the f_{2}(1270) is a molecular state made from the attractive interaction of two ρ mesons. Such a state would be expected to decay strongly to final states with charged pions due to the dominant decay ρâπ^{+}π^{-}, whereas decay to two neutral pions would likely be suppressed. Here, we measure for the first time the reaction γpâπ^{0}π^{0}p, using the CEBAF Large Acceptance Spectrometer detector at Jefferson Lab for incident beam energies between 3.6 and 5.4 GeV. Differential cross sections, dσ/dt, for f_{2}(1270) photoproduction are extracted with good precision due to low backgrounds and are compared to theoretical calculations.
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We measured missing mass spectrum of the ^{12}C(γ,p) reaction for the first time in coincidence with potential decay products from η^{'} bound nuclei. We tagged an (η+p) pair associated with the η^{'}NâηN process in a nucleus. After applying kinematical selections to reduce backgrounds, no signal events were observed in the bound-state region. An upper limit of the signal cross section in the opening angle cosθ_{lab}^{ηp}<-0.9 was obtained to be 2.2 nb/sr at the 90% confidence level. It is compared with theoretical cross sections, whose normalization ambiguity is suppressed by measuring a quasifree η^{'} production rate. Our results indicate a small branching fraction of the η^{'}NâηN process and/or a shallow η^{'}-nucleus potential.
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The FRAX algorithm assesses the patient's probability of sustaining an osteoporotic fracture and can be calculated with or without densitometric data. This study seeks to determine whether in men, FRAX scores calculated without BMD, correctly identify patients with BMD-defined osteoporosis. INTRODUCTION: The diagnosis of osteoporosis is based on densitometric data, the presence of a fragility fracture or increased fracture risk. The FRAX algorithm estimates the patient's 10-year probability of sustaining an osteoporotic fracture and can be calculated with or without BMD data. The purpose of this study is to determine whether in men, FRAX calculated without BMD, can correctly identify patients with BMD-defined osteoporosis. METHODS: Retrospectively retrieved data from 726 consecutive Caucasian males, 50 to 70 years old referred to our Osteoporosis Center. RESULTS: In the population studied, 11.8 and 25.3% had BMD-defined osteoporosis when female and male reference populations were used respectively. When the National Osteoporosis Foundation thresholds to initiate treatment are used, only 27% of patients with BMD-defined osteoporosis, but 4% with normal BMD reached/exceeded these thresholds. Lowering the threshold increased sensitivity, but decreased specificity. CONCLUSIONS: Our results suggest that FRAX without BMD is not sensitive/specific enough to be used to identify Caucasian men 50 to 70 years old with BMD-defined osteoporosis.
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Densidade Óssea/fisiologia , Osteoporose/diagnóstico , Idoso , Algoritmos , Densitometria , Colo do Fêmur/fisiopatologia , Articulação do Quadril/fisiopatologia , Humanos , Vértebras Lombares/fisiopatologia , Masculino , Pessoa de Meia-Idade , Osteoporose/fisiopatologia , Fraturas por Osteoporose/etiologia , Fraturas por Osteoporose/fisiopatologia , Fraturas por Osteoporose/prevenção & controle , Curva ROC , Estudos Retrospectivos , Medição de Risco/métodosRESUMO
The structure of deformed neutron-rich nuclei in the rare-earth region is of significant interest for both the astrophysics and nuclear structure fields. At present, a complete explanation for the observed peak in the elemental abundances at Aâ¼160 eludes astrophysicists, and models depend on accurate quantities, such as masses, lifetimes, and branching ratios of deformed neutron-rich nuclei in this region. Unusual nuclear structure effects are also observed, such as the unexpectedly low energies of the first 2^{+} levels in some even-even nuclei at N=98. In order to address these issues, mass and ß-decay spectroscopy measurements of the ^{160}Eu_{97} and ^{162}Eu_{99} nuclei were performed at the Californium Rare Isotope Breeder Upgrade radioactive beam facility at Argonne National Laboratory. Evidence for a gap in the single-particle neutron energies at N=98 and for large deformation (ß_{2}â¼0.3) is discussed in relation to the unusual phenomena observed at this neutron number.
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Differential cross sections and photon-beam asymmetries for the γ[over â]pâπ^{-}Δ^{++}(1232) reaction have been measured for 0.7
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PURPOSE: Firstly, to establish whether oral contraceptive pill (OCP) users are more susceptible to muscle damage compared to non-users, and secondly, to establish whether differences can be attributed to differences in patella tendon properties. METHODS: Nine female OCP users and 9 female non-users participated in the investigation. Combining dynamometry, electromyography and ultrasonography, patella tendon properties and vastus lateralis architectural properties were measured pre and during the first of 6 sets of 12 maximal voluntary eccentric knee extensions. Serum oestrogen levels were measured on the 7th day of the pill cycle and the 14th day of menstrual cycle in OCP users and non-users, respectively. Maximal voluntary isometric knee extension torque loss, creatine kinase and muscle soreness were measured 48 h pre-damage, post-damage, and 48, 96 and 168 h post-damage. RESULTS: Oestrogen levels were significantly lower in OCP users compared to non-users (209 ± 115 and 433 ± 147 pg/ml, respectively, p = 0.004). Proposed determinants of muscle damage, patella tendon stiffness and maximal eccentric torque did not differ between OCP users and non-users. The change in creatine kinase from pre to peak was significantly higher in OCP users compared to non-users (962 ± 968 and 386 ± 474 Ul, respectively, p = 0.016). There were no other differences in markers of muscle damage. CONCLUSION: Although our findings suggest that, when compared to non-users, the OCP may augment the creatine kinase response following eccentric exercise, it does not increase the susceptibility to any other markers of muscle damage.
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Anticoncepcionais Orais/efeitos adversos , Exercício Físico , Contração Isométrica , Mialgia/etiologia , Adulto , Estudos de Casos e Controles , Creatina Quinase/sangue , Estrogênios/sangue , Feminino , Humanos , Músculo Esquelético/fisiologia , Ligamento Patelar/fisiologia , TorqueRESUMO
The Ï-Λ(1520) interference effect in the γpâK^{+}K^{-}p reaction has been measured for the first time in the energy range from 1.673 to 2.173 GeV. The relative phases between Ï and Λ(1520) production amplitudes were obtained in the kinematic region where the two resonances overlap. The measurement results support strong constructive interference when K^{+}K^{-} pairs are observed at forward angles but destructive interference for proton emission at forward angles. Furthermore, the observed interference effect does not account for the sqrt[s]=2.1 GeV bump structure in forward differential cross sections for Ï photoproduction. This fact suggests possible exotic structures such as a hidden-strangeness pentaquark state, a new Pomeron exchange, or rescattering processes via other hyperon states.
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BACKGROUND: GSK2586184 is a selective oral Janus kinase (JAK)1 inhibitor being evaluated as a treatment for moderate-to-severe plaque-type psoriasis. OBJECTIVES: To assess the relationship between dose of GSK2586184 and clinical response, primarily by the Psoriasis Area Severity Index (PASI). METHODS: Sixty patients with moderate-to-severe plaque psoriasis were randomized to cohort A: 100 mg, 200 mg or 400 mg GSK2586184 twice daily or placebo; and eight were randomized to open-label cohort B, a small exploratory cohort treated with 400 mg GSK2586184 twice daily, to explore differential gene expression. RESULTS: At week 12, a 75% reduction in PASI (PASI 75) response rates in the intent-to-treat population were 0% in the placebo group compared with 13%, 25% and 57% in the 100 mg, 200 mg and 400 mg GSK2586184 twice-daily groups, respectively. Increases in the proportion of PASI 75 responses were seen across all dose levels by week 4. Improvement in itch and quality of life were observed at all doses relative to placebo with the greatest improvement seen in the 400-mg dose group. Overall, the incidence of adverse events (AEs) was similar across treatment groups, and no relationship between frequency of AE and GSK2586184 dose was identified. Differential gene expression was observed in involved and uninvolved skin at baseline and in involved skin after 2 weeks of treatment with GSK2586184. CONCLUSIONS: Our study demonstrates that 12 weeks of treatment with GSK2586184 resulted in clinical improvement and was generally well tolerated in patients with moderate-to-severe plaque-type psoriasis.
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Azetidinas/administração & dosagem , Fármacos Dermatológicos/administração & dosagem , Psoríase/tratamento farmacológico , Triazóis/administração & dosagem , Adolescente , Adulto , Idoso , Azetidinas/farmacocinética , Fármacos Dermatológicos/farmacocinética , Relação Dose-Resposta a Droga , Método Duplo-Cego , Esquema de Medicação , Feminino , Expressão Gênica , Humanos , Janus Quinase 1/antagonistas & inibidores , Masculino , Pessoa de Meia-Idade , Psoríase/genética , Qualidade de Vida , Resultado do Tratamento , Triazóis/farmacocinética , Adulto JovemRESUMO
We aimed to evaluate the pharmacodynamics, efficacy, safety and tolerability of the JAK1 inhibitor GSK2586184 in adults with systemic lupus erythematosus (SLE). In this adaptive, randomized, double-blind, placebo-controlled study, patients received oral GSK2586184 50-400 mg, or placebo twice daily for 12 weeks. Primary endpoints included interferon-mediated messenger RNA transcription over time, changes in Safety of Estrogen in Lupus National Assessment-SLE Disease Activity Index score, and number/severity of adverse events. A pre-specified interim analysis was performed when ≥ 5 patients per group completed 2 weeks of treatment. In total, 84-92% of patients were high baseline expressors of the interferon transcriptional biomarkers evaluated. At interim analysis, GSK2586184 showed no significant effect on mean interferon transcriptional biomarker expression (all panels). The study was declared futile and recruitment was halted at 50 patients. Shortly thereafter, significant safety data were identified, including elevated liver enzymes in six patients (one confirmed and one suspected case of Drug Reaction with Eosinophilia and Systemic Symptoms), leading to immediate dosing cessation. Safety of Estrogen in Lupus National Assessment-SLE Disease Activity Index scores were not analysed due to the small number of patients completing the study. The study futility and safety data described for GSK2586184 do not support further evaluation in patients with SLE. Study identifiers: GSK Study JAK115919; ClinicalTrials.gov identifier: NCT01777256.
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Azetidinas/administração & dosagem , Azetidinas/efeitos adversos , Janus Quinase 1/antagonistas & inibidores , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Triazóis/administração & dosagem , Triazóis/efeitos adversos , Administração Oral , Adulto , Azetidinas/farmacologia , Relação Dose-Resposta a Droga , Método Duplo-Cego , Esquema de Medicação , Feminino , Humanos , Interferons/genética , Lúpus Eritematoso Sistêmico/enzimologia , Masculino , Pessoa de Meia-Idade , Falha de Tratamento , Resultado do Tratamento , Triazóis/farmacologia , Adulto JovemRESUMO
The US Food and Drug Administration (FDA) Biomarker Qualification Review Team presents its perspective on the recent qualification of cardiac troponins for use in nonclinical safety assessment studies. The goal of this manuscript is to provide greater transparency into the qualification process and factors that were considered in reaching a regulatory decision. This manuscript includes an overview of the data that were submitted and a discussion of the strengths and shortcomings of these data supporting the qualification decision. The cardiac troponin submission is the first literature-based biomarker application to be reviewed by the FDA and insights gained from this experience may aid future submissions and help streamline the characterization and qualification of future biomarkers.
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Miocárdio/química , Troponina/análise , Animais , Biomarcadores/análise , Aprovação de Drogas , Humanos , Estados Unidos , United States Food and Drug AdministrationRESUMO
The exclusive reaction γpâK(+)π(-)Σ(+) was measured for the first time using linearly polarized photons at beam energies from 1.85 to 2.96 GeV. Angular distributions in the rest frame of the K(+)π(-) system were fitted to extract spin-density matrix elements of the K(*0) decay. The measured parity spin asymmetry shows that natural-parity exchange is dominant in this reaction. This result clearly indicates the need for t-channel exchange of the κ(800) scalar meson.
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BACKGROUND: Innovative approaches to the widespread delivery of evidence-based dementia care are needed. The aims of this study were to determine whether a telephone screening method could efficiently identify individuals in the community in need of care for dementia and to develop a multidimensional needs assessment tool for identifying the type and frequency of unmet needs related to memory disorders in the home setting. METHODS: This was a cross-sectional evaluation of 292 community-residing individuals aged 70 and older in Maryland. Participants were given a brief cognitive telephone screen. A subsample (n=43) received a comprehensive in-home assessment for dementia and dementia-related needs. Cognitive, functional, behavioral, and clinical factors were assessed. The Johns Hopkins Dementia Care Needs Assessment (JHDCNA) was used to identify unmet needs related to dementia. RESULTS: Telephone screening for the sample took 350 h, and 27% screened positive for dementia. Virtually all participants with dementia who received an in-home assessment had at least one unmet need, with the most frequent unmet needs being for a dementia workup, general medical care, environmental safety, assistance with ADL impairments, and access to meaningful activities. Caregivers, when present, also had a number of unmet needs, with the most common being caregiver education about dementia, knowledge of community resources, and caregiver mental health care. CONCLUSIONS: Effective and efficient means for identifying community-residing individuals with dementia are needed so that dementia care interventions can be provided to address unmet care needs of patients and their caregivers.
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Demência/diagnóstico , Demência/terapia , Necessidades e Demandas de Serviços de Saúde , Idoso , Idoso de 80 Anos ou mais , Serviços Comunitários de Saúde Mental/organização & administração , Estudos Transversais , Feminino , Pesquisas sobre Atenção à Saúde , Humanos , Masculino , Maryland , Programas de Rastreamento/métodos , Avaliação das Necessidades , TelefoneRESUMO
Differential cross sections and photon-beam asymmetries for the gamma(p)-->K{+}Lambda(1520) reaction have been measured with linearly polarized photon beams at energies from the threshold to 2.4 GeV at 0.6
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Atmospheric nitrogen (N) deposition is a recognized threat to plant diversity in temperate and northern parts of Europe and North America. This paper assesses evidence from field experiments for N deposition effects and thresholds for terrestrial plant diversity protection across a latitudinal range of main categories of ecosystems, from arctic and boreal systems to tropical forests. Current thinking on the mechanisms of N deposition effects on plant diversity, the global distribution of G200 ecoregions, and current and future (2030) estimates of atmospheric N-deposition rates are then used to identify the risks to plant diversity in all major ecosystem types now and in the future. This synthesis paper clearly shows that N accumulation is the main driver of changes to species composition across the whole range of different ecosystem types by driving the competitive interactions that lead to composition change and/or making conditions unfavorable for some species. Other effects such as direct toxicity of nitrogen gases and aerosols, long-term negative effects of increased ammonium and ammonia availability, soil-mediated effects of acidification, and secondary stress and disturbance are more ecosystem- and site-specific and often play a supporting role. N deposition effects in mediterranean ecosystems have now been identified, leading to a first estimate of an effect threshold. Importantly, ecosystems thought of as not N limited, such as tropical and subtropical systems, may be more vulnerable in the regeneration phase, in situations where heterogeneity in N availability is reduced by atmospheric N deposition, on sandy soils, or in montane areas. Critical loads are effect thresholds for N deposition, and the critical load concept has helped European governments make progress toward reducing N loads on sensitive ecosystems. More needs to be done in Europe and North America, especially for the more sensitive ecosystem types, including several ecosystems of high conservation importance. The results of this assessment show that the vulnerable regions outside Europe and North America which have not received enough attention are ecoregions in eastern and southern Asia (China, India), an important part of the mediterranean ecoregion (California, southern Europe), and in the coming decades several subtropical and tropical parts of Latin America and Africa. Reductions in plant diversity by increased atmospheric N deposition may be more widespread than first thought, and more targeted studies are required in low background areas, especially in the G200 ecoregions.
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Biodiversidade , Nitrogênio/química , Nitrogênio/metabolismo , Plantas/classificação , Plantas/metabolismo , Meio Ambiente , Monitoramento Ambiental , Fixação de NitrogênioRESUMO
The larva of the green lacewing Chrysopa slossonae lives in colonies of the wooly alder aphid Prociphilus tesselatus upon which it feeds. It disguises itself as its prey by plucking some of the waxy "wool" from the bodies of the aphids and applying this material to its own back. The investiture protects it from assault by the ants that ordinarily "shepherd" the aphids. Larvae artifically denuded are seized by the ants and removed from the aphid colonies. A larva requires on the average less than 20 minutes to coat itself with wax. A hungry denuded larva gives the coating procedure about the same behavioral priority as feeding.
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The exocrine secretion of the "stinkpot turtle," Sternotherus odoratus, discharged by the animals in response to disturbance, contains four omega-phenylalkanoic acids (phenylacetic, 3-phenylpropionic, 5-phenylpentanoic, and 7-phenylheptanoic). The last two of these are new natural products. The first two are powerfully malodorous and responsible for the stench of the fluid. Lesser components, including several aliphatic acids, are also present. Only a few milligrams of secretion are discharged by a turtle at any one time. Although bioassays with fish suggest that the secretion has the potential to serve as a feeding deterrent to predators, it is argued that Sternotherus does not ordinarily discharge enough fluid to effect this action and may employ its secretion only as an aposematic signal that warns predators of its more generalized undesirability.
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A nitrogen-containing terpene 6,6-dimethyl-2-azaspiro[4.4]non-1-ene (polyzonimine) was isolated from the defensive secretion of the milliped Polyzonium rosalbum. Polyzonimine, which is repellent to such natural enemies of the milliped as ants, acts as a topical irritant to insects (10-4 M induces scratching in cockroaches). Its structure was confirmed by a five-step synthesis starting from 2,2-dimethyl-7-oxabicyclo[4.1.0]heptane.
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Artrópodes/metabolismo , Repelentes de Insetos , Terpenos/farmacologia , Animais , Formigas , Artrópodes/ultraestrutura , Baratas , Microscopia Eletrônica de Varredura , Terpenos/isolamento & purificaçãoRESUMO
Photoperiodic responses, such as the daylength-dependent control of reproductive development, are associated with a circadian biological clock. The photoperiod-insensitive early-flowering 3 (elf3) mutant of Arabidopsis thaliana lacks rhythmicity in two distinct circadian-regulated processes. This defect was apparent only when plants were assayed under constant light conditions. elf3 mutants retain rhythmicity in constant dark and anticipate light/dark transitions under most light/dark regimes. The conditional arrhythmic phenotype suggests that the circadian pacemaker is intact in darkness in elf3 mutant plants, but the transduction of light signals to the circadian clock is impaired.