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1.
Phys Rev Lett ; 132(20): 202701, 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38829093

RESUMO

New astronomical observations point to a nucleosynthesis picture that goes beyond what was accepted until recently. The intermediate "i" process was proposed as a plausible scenario to explain some of the unusual abundance patterns observed in metal-poor stars. The most important nuclear physics properties entering i-process calculations are the neutron-capture cross sections and they are almost exclusively not known experimentally. Here we provide the first experimental constraints on the ^{139}Ba(n,γ)^{140}Ba reaction rate, which is the dominant source of uncertainty for the production of lanthanum, a key indicator of i-process conditions. This is an important step towards identifying the exact astrophysical site of stars carrying the i-process signature.

2.
Rev Sci Instrum ; 93(1): 013306, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-35104937

RESUMO

A challenge preventing successful inverse kinematics measurements with heavy nuclei that are not fully stripped is identifying and tagging the beam particles. For this purpose, the HEavy ISotope Tagger (HEIST) has been developed. HEIST utilizes two micro-channel plate timing detectors to measure the time-of-flight, a multi-sampling ion chamber to measure energy loss, and a high-purity germanium detector to identify isomer decays and calibrate the isotope identification system. HEIST has successfully identified 198Pb and other nearby nuclei at energies of about 75 MeV/A. In the experiment discussed, a typical cut containing 89% of all 198Pb80+ in the beam had a purity of 86%. We examine the issues of charge state contamination. The observed charge state populations of these ions are presented and, using an adjusted beam energy, are well described by the charge state model GLOBAL.

3.
Obes Res Clin Pract ; 16(1): 37-43, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35094958

RESUMO

BACKGROUND/OBJECTIVES: Body composition and anthropometry assessment from two-dimensional smartphone images is possible through advancement of computational hardware and artificial intelligence (AI) techniques. This study established agreement of a novel smartphone assessment, compared with traditional bioelectrical impedance analysis (BIA), and criterion measures. SUBJECTS/METHODS: Body composition of 929 adults was measured using DXA (GE lunar iDXA), a foot-to-foot BIA machine (TANITA BC-313), and predictions from two-dimensional smartphone images. Anthropometry measures were also collected. Body composition and anthropometry estimates were compared via concordance coefficient correlation (CCC), equivalence testing, Bland-Altman analysis, and root mean square error (RMSE). RESULTS: 2D smartphone image predictions for percent body fat (%BF) (males: CCC = 0.90 and RMSE = 2.9, and females: CCC = 0.90 and RMSE = 2.8) reported greater agreement with DXA measures than the BIA measures (males: CCC = 0.66 and RMSE = 5.6, and females: CCC = 0.79 and RMSE = 4.6). All anthropometry 2D smartphone image predictions had a strong agreement with criterion measurements (CCC ≥ 0.84 and RMSE ≤ 3.3). Body composition and anthropometry measures predicted by the 2D smartphone images were clinically equivalent at ±2.5 and ±5.0% thresholds. BIA %BF was not equivalent at either threshold; with only female BIA fat-free mass equivalent at the ±5% threshold. CONCLUSION: Body composition predictions from 2D smartphone application images provide a promising alternative to BIA scales for in-home body composition assessment. Future research should assess the validity of this method for longitudinally tracking body composition and indicating an individual's potential risk of chronic diseases.


Assuntos
Inteligência Artificial , Smartphone , Absorciometria de Fóton , Adulto , Antropometria/métodos , Composição Corporal , Índice de Massa Corporal , Impedância Elétrica , Feminino , Humanos , Masculino
4.
Microbiome ; 6(1): 220, 2018 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-30526683

RESUMO

BACKGROUND: Faecal microbiota transplantation (FMT) is used in the treatment of recurrent Clostridium difficile infection. Its success is typically attributed to the restoration of a diverse microbiota. Viruses (including bacteriophages) are the most numerically dominant and potentially the most diverse members of the microbiota, but their fate following FMT has not been well studied. RESULTS: We studied viral transfer following FMT from 3 donors to 14 patients. Recipient viromes resembled those of their donors for up to 12 months. Tracking individual bacteriophage colonisation revealed that engraftment of individual bacteriophages was dependent on specific donor-recipient pairings. Specifically, multiple recipients from a single donor displayed highly individualised virus colonisation patterns. CONCLUSIONS: The impact of viruses on long-term microbial dynamics is a factor that should be reviewed when considering FMT as a therapeutic option.


Assuntos
Bacteriófagos/classificação , Infecções por Clostridium/terapia , Transplante de Microbiota Fecal/métodos , Bacteriófagos/isolamento & purificação , Infecções por Clostridium/virologia , Fezes/virologia , Humanos , Metagenômica , Filogenia , Doadores de Tecidos
5.
Epidemiol Infect ; 146(14): 1845-1853, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30070187

RESUMO

Mixing matrices quantify how people with similar or different characteristics make contact with each other, creating potential for disease transmission. Little empirical data on mixing patterns among persons who inject drugs (PWID) are available to inform models of blood-borne disease such as HIV and hepatitis C virus. Egocentric drug network data provided by PWID in Baltimore, Maryland between 2005 and 2007 were used to characterise drug equipment-sharing patterns according to age, race and gender. Black PWID and PWID who were single (i.e. no stable sexual partner) self-reported larger equipment-sharing networks than their white and non-single counterparts. We also found evidence of assortative mixing according to age, gender and race, though to a slightly lesser degree in the case of gender. Highly assortative mixing according to race and gender highlights the existence of demographically isolated clusters, for whom generalised treatment interventions may have limited benefits unless targeted directly. These findings provide novel insights into mixing patterns of PWID for which little empirical data are available. The age-specific assortativity we observed is also significant in light of its role as a key driver of transmission for other pathogens such as influenza and tuberculosis.


Assuntos
Uso Comum de Agulhas e Seringas/estatística & dados numéricos , Abuso de Substâncias por Via Intravenosa/epidemiologia , Adulto , Fatores Etários , Baltimore/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores Sexuais , Adulto Jovem
7.
Lett Appl Microbiol ; 65(4): 319-326, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28736938

RESUMO

Pythium myriotylum is responsible for severe losses in both capsicum and ginger crops in Australia under different regimes. Intraspecific genomic variation within the pathogen might explain the differences in aggressiveness and pathogenicity on diverse hosts. In this study, whole genome data of four P. myriotylum isolates recovered from three hosts and one Pythium zingiberis isolate were derived and analysed for sequence diversity based on single nucleotide polymorphisms (SNPs). A higher number of true and unique SNPs occurred in P. myriotylum isolates obtained from ginger with symptoms of Pythium soft rot (PSR) in Australia compared to other P. myriotylum isolates. Overall, SNPs were discovered more in the mitochondrial genome than those in the nuclear genome. Among the SNPs, a single substitution from the cytosine (C) to the thymine (T) in the partially sequenced CoxII gene of 14 representatives of PSR P. myriotylum isolates was within a restriction site of HinP1I enzyme which was used in the PCR-RFLP for detection and identification of the isolates without sequencing. The PCR-RFLP was also sensitive to detect PSR P. myriotylum strains from artificially infected ginger without the need for isolation for pure cultures. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first study of intraspecific variants of Pythium myriotylum isolates recovered from different hosts and origins based on single nucleotide polymorphism (SNP) genotyping of multiple genes. The SNPs discovered provide valuable makers for detection and identification of P. myriotylum strains initially isolated from Pythium soft rot (PSR) ginger by using PCR-RFLP of the CoxII locus. The PCR-RFLP was also sensitive to detect P. myriotylum directly from PSR ginger sampled from pot trials without the need of isolation for pure cultures.


Assuntos
DNA Mitocondrial/genética , Doenças das Plantas/parasitologia , Polimorfismo de Nucleotídeo Único/genética , Pythium/genética , Zingiber officinale/parasitologia , Austrália , Sequência de Bases , Capsicum/parasitologia , Marcadores Genéticos/genética , Genótipo , Mitocôndrias/genética , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Pythium/classificação , Pythium/isolamento & purificação
8.
CPT Pharmacometrics Syst Pharmacol ; 6(5): 285-292, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28504472

RESUMO

Pharmacometric analyses are complex and multifactorial. It is essential to check, track, and document the vast amounts of data and metadata that are generated during these analyses (and the relationships between them) in order to comply with regulations, support quality control, auditing, and reporting. It is, however, challenging, tedious, error-prone, and time-consuming, and diverts pharmacometricians from the more useful business of doing science. Automating this process would save time, reduce transcriptional errors, support the retention and transfer of knowledge, encourage good practice, and help ensure that pharmacometric analyses appropriately impact decisions. The ability to document, communicate, and reconstruct a complete pharmacometric analysis using an open standard would have considerable benefits. In this article, the Innovative Medicines Initiative (IMI) Drug Disease Model Resources (DDMoRe) consortium proposes a set of standards to facilitate the capture, storage, and reporting of knowledge (including assumptions and decisions) in the context of model-informed drug discovery and development (MID3), as well as to support reproducibility: "Thoughtflow." A prototype software implementation is provided.


Assuntos
Descoberta de Drogas , Modelos Biológicos , Software , Humanos , Fluxo de Trabalho
9.
Phys Rev Lett ; 116(11): 112503, 2016 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-27035298

RESUMO

The neutron-rich nucleus ^{144}Ba (t_{1/2}=11.5 s) is expected to exhibit some of the strongest octupole correlations among nuclei with mass numbers A less than 200. Until now, indirect evidence for such strong correlations has been inferred from observations such as enhanced E1 transitions and interleaving positive- and negative-parity levels in the ground-state band. In this experiment, the octupole strength was measured directly by sub-barrier, multistep Coulomb excitation of a post-accelerated 650-MeV ^{144}Ba beam on a 1.0-mg/cm^{2} ^{208}Pb target. The measured value of the matrix element, ⟨3_{1}^{-}∥M(E3)∥0_{1}^{+}⟩=0.65(+17/-23) eb^{3/2}, corresponds to a reduced B(E3) transition probability of 48(+25/-34) W.u. This result represents an unambiguous determination of the octupole collectivity, is larger than any available theoretical prediction, and is consistent with octupole deformation.

10.
CPT Pharmacometrics Syst Pharmacol ; 4(6): 316-9, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26225259

RESUMO

The lack of a common exchange format for mathematical models in pharmacometrics has been a long-standing problem. Such a format has the potential to increase productivity and analysis quality, simplify the handling of complex workflows, ensure reproducibility of research, and facilitate the reuse of existing model resources. Pharmacometrics Markup Language (PharmML), currently under development by the Drug Disease Model Resources (DDMoRe) consortium, is intended to become an exchange standard in pharmacometrics by providing means to encode models, trial designs, and modeling steps.

11.
Int J STD AIDS ; 24(6): 441-6, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23970745

RESUMO

Herpes simplex virus type 2 (HSV-2) can contribute to the spread of HIV. From March 2006 to November 2009, female sex workers (FSWs) in Yunnan, China were recruited into an open cohort study to determine incidence and risk factors for HSV-2 acquisition. Participants were interviewed and tested for HSV-2 and other sexually transmitted infections (STIs) every six months. A multivariate Cox proportional hazards regression model with time-dependent variables was used to measure associations with HSV-2 acquisition. In 3.5 years, 83 incident cases of HSV-2 infection were diagnosed, yielding an overall incidence of 21.9 per 100 person years (PY) (95% confidence interval [CI], 17.8-26.3). Working in higher risk commercial sex venues, current Neisseria gonorrhoeae infection, age of sexual debut <18 years and lack of a regular sex partner were independent factors associated with HSV-2 acquisition. The high incidence of HSV-2 suggests that prevention methods for HIV/STI control are urgently needed.


Assuntos
Infecções por HIV/epidemiologia , Herpes Genital/epidemiologia , Herpesvirus Humano 2/isolamento & purificação , Profissionais do Sexo , Adolescente , Adulto , Idoso , China/epidemiologia , Coleta de Dados , Feminino , Infecções por HIV/prevenção & controle , Humanos , Incidência , Entrevistas como Assunto , Pessoa de Meia-Idade , Prevalência , Modelos de Riscos Proporcionais , Fatores de Risco , Trabalho Sexual/estatística & dados numéricos , Adulto Jovem
13.
Int J STD AIDS ; 23(9): 670-5, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23033525

RESUMO

To examine the HIV/sexually transmitted infection (STI)-related risk behaviours among community-based female sex workers (FSWs) and their clients in Yunnan Province, China, we performed a cross-sectional study of 705 FSWs and 100 male clients. We found that HIV seroprevalence among FSWs was 13.0% and the most prevalent STI was herpes simplex virus type 2 (HSV-2) (71.1%), followed by Chlamydia trachomatis (18.1%) and syphilis (8.8%). The 20% of FSWs who reported injection drug use also reported needle-sharing behaviours in the last three months. Drug-using FSWs had substantially higher HIV and HSV-2 prevalence, serviced more clients and had a longer history of sex work than non-using FSWs. In total, 57.0% of male clients did not consistently use condoms with FSWs, 2.0% reported illicit drug use and 17.0% had STI symptoms in the last year. The dual risk behaviours of drug-using FSWs and clients place them at greater risk of HIV infection. Intervention programmes must adopt comprehensive methods.


Assuntos
Usuários de Drogas/estatística & dados numéricos , Epidemias , Infecções por HIV/epidemiologia , Trabalho Sexual/estatística & dados numéricos , Comportamento Sexual/estatística & dados numéricos , Adolescente , Adulto , Idoso , China/epidemiologia , Preservativos , Estudos Transversais , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Uso Comum de Agulhas e Seringas , Prevalência , Assunção de Riscos , Inquéritos e Questionários
14.
Appl Radiat Isot ; 70(7): 1321-4, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22182628

RESUMO

The quadrupole deformations for the low-lying states in the transitional nuclei 100,101Pd have been deduced through the measurement of their electric quadrupole transition probabilities using the Recoil Distance Doppler Shift Method. The nuclei were studied using a 268 MeV 80Se beam impinging on a thin, self-supporting 24Mg target. States in 100Pd and 101Pd populated by the four and three neutron evaporation channels respectively, with reaction gamma-rays detected using the SPEEDY gamma-ray detection array. The recoiling nuclei were stopped in a copper foil and gamma-ray coincidence data taken at 10 separate target-stopper distances between 35 µm and 750 µm. The mean-lifetimes for the lowest lying 2+ (in 100Pd) and 15/2- (in 101Pd) states were measured to be 13.3(9) ps and 10.8(8) ps respectively. These data are compared with predictions from nuclear Total Routhian Surface calculations, which are found to agree with the experimentally deduced values to within 10%.

15.
CBE Life Sci Educ ; 10(1): 55-63, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21364100

RESUMO

Use of in-class concept questions with clickers can transform an instructor-centered "transmissionist" environment to a more learner-centered constructivist classroom. To compare the effectiveness of three different approaches using clickers, pairs of similar questions were used to monitor student understanding in majors' and nonmajors' genetics courses. After answering the first question individually, students participated in peer discussion only, listened to an instructor explanation only, or engaged in peer discussion followed by instructor explanation, before answering a second question individually. Our results show that the combination of peer discussion followed by instructor explanation improved average student performance substantially when compared with either alone. When gains in learning were analyzed for three ability groups of students (weak, medium, and strong, based on overall clicker performance), all groups benefited most from the combination approach, suggesting that peer discussion and instructor explanation are synergistic in helping students. However, this analysis also revealed that, for the nonmajors, the gains of weak performers using the combination approach were only slightly better than their gains using instructor explanation alone. In contrast, the strong performers in both courses were not helped by the instructor-only approach, emphasizing the importance of peer discussion, even among top-performing students.


Assuntos
Avaliação Educacional , Aprendizagem , Grupo Associado , Estudantes , Ensino/métodos , Currículo , Demografia , Feminino , Genética/educação , Humanos , Masculino
16.
Science ; 323(5910): 122-4, 2009 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-19119232

RESUMO

When students answer an in-class conceptual question individually using clickers, discuss it with their neighbors, and then revote on the same question, the percentage of correct answers typically increases. This outcome could result from gains in understanding during discussion, or simply from peer influence of knowledgeable students on their neighbors. To distinguish between these alternatives in an undergraduate genetics course, we followed the above exercise with a second, similar (isomorphic) question on the same concept that students answered individually. Our results indicate that peer discussion enhances understanding, even when none of the students in a discussion group originally knows the correct answer.


Assuntos
Genética/educação , Aprendizagem , Grupo Associado , Ensino/métodos , Compreensão , Avaliação Educacional , Humanos
17.
J Virol ; 82(6): 2883-94, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18199653

RESUMO

The severe acute respiratory syndrome coronavirus (SARS-CoV) spike glycoprotein (S) is a class I viral fusion protein that binds to its receptor glycoprotein, human angiotensin converting enzyme 2 (hACE2), and mediates virus entry and cell-cell fusion. The juxtamembrane domain (JMD) of S is an aromatic amino acid-rich region proximal to the transmembrane domain that is highly conserved in all coronaviruses. Alanine substitutions for one or two of the six aromatic residues in the JMD did not alter the surface expression of the SARS-CoV S proteins with a deletion of the C-terminal 19 amino acids (S Delta19) or reduce binding to soluble human ACE2 (hACE2). However, hACE2-dependent entry of trypsin-treated retrovirus pseudotyped viruses expressing JMD mutant S Delta19 proteins was greatly reduced. Single alanine substitutions for aromatic residues reduced entry to 10 to 60% of the wild-type level. The greatest reduction was caused by residues nearest the transmembrane domain. Four double alanine substitutions reduced entry to 5 to 10% of the wild-type level. Rapid hACE2-dependent S-mediated cell-cell fusion was reduced to 60 to 70% of the wild-type level for all single alanine substitutions and the Y1188A/Y1191A protein. S Delta19 proteins with other double alanine substitutions reduced cell-cell fusion further, from 40% to less than 20% of wild-type levels. The aromatic amino acids in the JMD of the SARS-CoV S glycoprotein play critical roles in receptor-dependent virus-cell and cell-cell fusion. Because the JMD is so highly conserved in all coronavirus S proteins, it is a potential target for development of drugs that may inhibit virus entry and/or cell-cell fusion mediated by S proteins of all coronaviruses.


Assuntos
Aminoácidos Aromáticos/fisiologia , Fusão Celular , Glicoproteínas de Membrana/fisiologia , Proteínas de Membrana/fisiologia , Receptores Virais/fisiologia , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/fisiologia , Proteínas do Envelope Viral/fisiologia , Sequência de Aminoácidos , Aminoácidos Aromáticos/química , Sequência de Bases , Linhagem Celular , Primers do DNA , Humanos , Glicoproteínas de Membrana/química , Proteínas de Membrana/química , Dados de Sequência Molecular , Receptores Virais/química , Homologia de Sequência de Aminoácidos , Glicoproteína da Espícula de Coronavírus , Proteínas do Envelope Viral/química
20.
Recurso na Internet em Inglês | LIS - Localizador de Informação em Saúde | ID: lis-10818

RESUMO

It provides some definitions for social capital, and presents information on its dimensions, the decline in social capital, its benefits, and social capital in organizations.


Assuntos
Organização e Administração , Gestão do Conhecimento , Gestão da Informação
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