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1.
Phys Rev Lett ; 124(8): 080501, 2020 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-32167314

RESUMO

The only known way to study quantum field theories in nonperturbative regimes is using numerical calculations regulated on discrete space-time lattices. Such computations, however, are often faced with exponential signal-to-noise challenges that render key physics studies untenable even with next generation classical computing. Here, a method is presented by which the output of small-scale quantum computations on noisy intermediate-scale quantum era hardware can be used to accelerate larger-scale classical field theory calculations through the construction of optimized interpolating operators. The method is implemented and studied in the context of the 1+1-dimensional Schwinger model, a simple field theory which shares key features with the standard model of nuclear and particle physics.

2.
Ir Med J ; 113(7): 119, 2020 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-35574822

RESUMO

Aims Our aim was to assess if outcomes for cystic fibrosis (CF) patients at six & sixteen years of age have improved in the last 17 years looking at FEV1, BMI and death. Methods A retrospective observational study using a prospectively maintained database of CF patients at Cork University Hospital. Results 84 patients were included in the 16-year-old data and 89 patients were included in the six-year-old data. The mean FEV1 and BMI (16 years) for the 2002-2007 group was 72.9±21.0% and 18.9±2.53 respectively, 2008-2013 group was 75.4±27.2% and 19.8±2.7 and for the 2014-2018 group was 95.2±16.0% and 22.9±4.1. The percentage of patients (16 years) with chronic pseudomonas status was 37.9% (11/30) in the 2002-2007 group, 51.6 % (16/31) in the 2008-2013 group and 4.2% (1/24) in the 2014-2018 group. The relationship between FEV1 and FVC with BMI remained significant in multivariate analysis (P <0.001). The mean FEV1 (six years) for the 2002-2007 group was 90.7±16.1%, 2008-2013 group was 99.3±17.9% and for the 2014-2018 group was 100.9±15.8%. Conclusions Improvements in FEV1 and BMI aged six and 16 years are notable as well as a significant decline in the number of patients with chronic pseudomonas.

3.
Phys Rev Lett ; 122(7): 072003, 2019 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-30848655

RESUMO

The distributions of pressure and shear forces inside the proton are investigated using lattice quantum chromodynamics (LQCD) calculations of the energy momentum tensor, allowing the first model-independent determination of these fundamental aspects of proton structure. This is achieved by combining recent LQCD results for the gluon contributions to the energy momentum tensor with earlier calculations of the quark contributions. The utility of LQCD calculations in exploring, and supplementing, the assumptions in a recent extraction of the pressure distribution in the proton from deeply virtual Compton scattering is also discussed. Based on this study, the target kinematics for experiments aiming to determine the pressure and shear distributions with greater precision at Thomas Jefferson National Accelerator Facility and a future electron ion collider are investigated.

4.
J Intellect Disabil Res ; 63(5): 372-385, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30628125

RESUMO

BACKGROUND: Current literature highlights higher prevalence rates of sleep difficulties amongst adults with an intellectual disability. However, no synthesis has been conducted to assess the effectiveness of existing interventions in this population. Thus, the aim of this review was to assess the effectiveness of sleep interventions in adults with an intellectual disability (ID). METHOD: Eight databases were searched to identify interventions for sleep difficulties amongst adults with an ID. The study quality was assessed with the Risk Of Bias In Non-randomised Studies - of Interventions. Nine studies (n = 97) were eligible for inclusion in the review. RESULTS: There was a notable study on heterogeneity in terms of the population, study design, intervention studied, sleep assessment and outcome assessments used. Eight of the nine studies reported improvement in sleep following intervention. However, these findings need additional support as only 97 participants involving a variety of interventions and measurement systems were used across all studies. Furthermore, eight of the nine studies had serious to critical risk of bias. The only study identified as having low risk of bias was a placebo-controlled randomised controlled trial for the use of melatonin. CONCLUSIONS: This review highlights the need for objective measures such as actigraphy and studies with greater experimental control investigating sleep interventions in adults with ID.


Assuntos
Deficiência Intelectual , Transtornos do Sono-Vigília/diagnóstico , Transtornos do Sono-Vigília/terapia , Adulto , Comorbidade , Humanos , Deficiência Intelectual/epidemiologia , Transtornos do Sono-Vigília/epidemiologia
5.
Plant Soil ; 415(1): 407-422, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-32025056

RESUMO

BACKGROUND AND AIMS: There is an urgent need to develop new high throughput approaches to phenotype roots in the field. Excavating roots to make direct measurements is labour intensive. An alternative to excavation is to measure soil drying profiles and to infer root activity. METHODS: We grew 23 lines of wheat in 2013, 2014 and 2015. In each year we estimated soil water profiles with electrical resistance tomography (ERT), electromagnetic inductance (EMI), penetrometer measurements and measurements of soil water content. We determined the relationships between the measured variable and soil water content and matric potential. RESULTS: We found that ERT and penetrometer measurements were closely related to soil matric potential and produced the best discrimination between wheat lines. We found genotypic differences in depth of water uptake in soil water profiles and in the extent of surface drying. CONCLUSIONS: Penetrometer measurements can provide a reliable approach to comparing soil drying profiles by different wheat lines, and genotypic rankings are repeatable across years. EMI, which is more sensitive to soil water content than matric potential, and is less effective in drier soils than the penetrometer or ERT, nevertheless can be used to rapidly screen large populations for differences in root activity.

6.
Phys Rev Lett ; 114(9): 091802, 2015 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-25793800

RESUMO

The strange contribution to the electric and magnetic form factors of the nucleon is determined at a range of discrete values of Q^{2} up to 1.4 GeV^{2}. This is done by combining a recent analysis of lattice QCD results for the electromagnetic form factors of the octet baryons with experimental determinations of those quantities. The most precise result is a small negative value for the strange magnetic moment: G_{M}^{s}(Q^{2}=0)=-0.07±0.03µ_{N}. At larger values of Q^{2} both the electric and magnetic form factors are consistent with zero to within 2 standard deviations.

7.
Water Res ; 75: 270-81, 2015 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-25770447

RESUMO

Surface water contamination by human faecal wastes is a widespread hazard for human health. Faecal indicator bacteria (FIB) are the most widely used indicators to assess surface water quality but are less-human-specific and have the potential to survive longer and/or occur naturally in tropical areas. In this study, 13 wastewater chemicals (chloride, boron, orthosphophate, detergents as methylene blue active substances, cholesterol, cholestanol, coprostanol, diethylhexyl phthalate, caffeine, acetaminophen, ibuprofen, sucralose and saccharin) were investigated in order to evaluate tracers for human faecal and sewage contamination in tropical urban catchments. Surface water samples were collected at an hourly interval from sampling locations with distinct major land uses: high-density residential, low-density residential, commercial and industrial. Measured concentrations were analysed to investigate the association among indicators and tracers for each land-use category. Better correlations were found between different indicators and tracers in each land-use dataset than in the dataset for all land uses, which shows that land use is an important determinant of drain water quality. Data were further segregated based on the hourly FIB concentrations. There were better correlations between FIB and chemical tracers when FIB concentrations were higher. Therefore, sampling programs must be designed carefully to take the time of sampling and land use into account in order to effectively assess human faecal and sewage contamination in urban catchments. FIB is recommended as the first tier in assessment of surface water quality impairment and chemical tracers as the second tier. Acetaminophen and coprostanol are recommended as chemical tracers for high-density residential areas, while chloride, coprostanol and caffeine are recommended for low-density residential areas.


Assuntos
Bactérias/isolamento & purificação , Biomarcadores/análise , Monitoramento Ambiental , Água Doce/análise , Águas Residuárias/análise , Poluentes Químicos da Água/análise , Fezes/microbiologia , Humanos , Estações do Ano , Singapura , Clima Tropical
8.
Water Res ; 68: 171-81, 2015 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-25462726

RESUMO

Human faecal contamination poses a widespread hazard for human health. In urban areas, sewer leakage may be an important cause of faecal pollution to surface water. Faecal indicator bacteria (FIB) are the most widely used indicators to monitor surface water quality. However, assessing whether a water body is meeting water quality criteria is made difficult by the high variability of FIB concentrations over time. In this study, the variation of FIB concentration in surface water from tropical urban catchments is investigated. Eleven urban sub-catchments were sampled hourly over 24-hr and samples analysed for FIB. It was found that FIB show a diurnal pattern that is characterised by daytime FIB concentrations that are significantly higher than nighttime FIB concentrations. This observed diurnal variation of FIB closely follows that of sewer flows and contrasts with observations in rural streams where FIB concentrations are known to be low in the daytime and high during the night. Field tracer tests provide qualitative evidence of sewage exfiltration and transport to drains via preferential flow paths. The diurnal FIB variation and field tracer tests indicate the likelihood of surface water contamination due to leaking sewers. The results further suggest that contamination of surface-water drains is likely a widespread problem in tropical urban areas due to extensive drainage networks and the persistence of FIB under tropical conditions. Because of FIB variation over time, the time at which samples are collected is important in being able to capture the daily maximum and minimum FIB concentrations. The Kruskal-Wallis test shows that hourly sampling from 04:00 to 07:00 and from 12:00 to 15:00 results in significantly different FIB concentration (minimum and maximum, respectively). Furthermore, the Wilcoxon-Mann-Whitney test shows that sampling at 12:00 and 14:00 results in significantly higher FIB concentrations, while sampling at 05:00 and 04:00 or 05:00 and 06:00 results in significantly lower FIB concentrations, than sampling at other hours of the day.


Assuntos
Bactérias/isolamento & purificação , Monitoramento Ambiental , Fezes/microbiologia , Esgotos/análise , Águas Residuárias/microbiologia , Singapura , Fatores de Tempo , Clima Tropical
9.
J Appl Microbiol ; 116(5): 1369-83, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24460587

RESUMO

AIMS: The study goals were to determine the relationship between faecal indicator bacteria (FIB), the HF183 marker and land use, and the phylogenetic diversity of HF183 marker sequences in a tropical urban watershed. METHODS AND RESULTS: Total coliforms, Escherichia coli, and HF183 were quantified in 81 samples categorized as undeveloped, residential and horticultural from the Kranji Reservoir and Catchment in Singapore. Quantitative-PCR for HF183 followed by analysis of variance indicated that horticultural areas had significantly higher geometric means for marker levels (4·3 × 10(4) HF183-GE 100 ml(-1)) than nonhorticultural areas (3·07 × 10(3) HF183-GE 100 ml(-1)). E. coli and HF183 were moderately correlated in horticultural areas (R = 0·59, P = 0·0077), but not elsewhere in the catchment. Initial upstream surveys of candidate sources revealed elevated HF183 in a wastewater treatment effluent but not in aquaculture ponds. The HF183 marker was cloned, sequenced and determined by phylogenetic analysis to match the original marker description. CONCLUSION: We show that quantification of the HF183 marker is a useful tool for mapping the spatial distribution and potential sources of human sewage contamination in tropical environments such as Singapore. SIGNIFICANCE AND IMPACT: A major challenge for assessment of water quality in tropical environments is the natural occurrence and nonconservative behaviour of FIB. The HF183 marker has been employed in temperate environments as an alternative indicator for human sewage contamination. Our study supports the use of the HF183 marker as an indicator for human sewage in Singapore and motivates further work to determine HF183 marker levels that correspond to public health risk in tropical environments.


Assuntos
Bacteroides/isolamento & purificação , Microbiologia da Água , Bacteroides/classificação , Bacteroides/genética , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Fezes/microbiologia , Marcadores Genéticos , Filogenia , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/genética , Esgotos/microbiologia , Singapura , Clima Tropical , Qualidade da Água
10.
Eur J Neurol ; 21(2): 338-43, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24313966

RESUMO

BACKGROUND AND PURPOSE: Greater occipital nerve blockade (GONB) has been shown to be effective in episodic cluster headache. However, its use in chronic cluster headache (CCH) is less certain. The study aims to prospectively assess the efficacy and consistency of response to GONB in a large series of CCH patients. METHODS: CCH patients who had a unilateral GONB and were referred to the National Hospital for Neurology and Neurosurgery were studied prospectively. Headache characteristics were collected using headache diaries. Responders were considered to be patients with a complete or partial response lasting at least 7 days. In a subgroup of responders the outcomes of serial GONB performed at 3-monthly intervals were also analysed. RESULTS: Eighty-three CCH patients were studied. After the first GONB, a positive response was observed in 47 (57%) patients: 35 (42%) were rendered pain free, 12 (15%) had a partial benefit and one patient obtained <50% improvement. The duration of a positive response lasted a median of 21 days (range 7-504 days). There was a transient worsening of condition in 6% of patients. The overall rate and average duration of response remained consistent after the second [n = 37; 31 responders (84%); median duration 21 days], third [n = 28; 20 responders (71%); median duration 25 days] and fourth [n = 14; 10 responders (71%); median duration 23 days] injections. CONCLUSION: GONB seems to be an efficacious treatment with reproducible effects in CCH patients. Performed three monthly, GONB may have a useful role in the management of CCH.


Assuntos
Analgésicos/uso terapêutico , Cefaleia Histamínica/tratamento farmacológico , Lidocaína/uso terapêutico , Metilprednisolona/uso terapêutico , Bloqueio Nervoso/métodos , Adulto , Idoso , Quimioterapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Resultado do Tratamento , Adulto Jovem
11.
Phys Rev Lett ; 110(20): 202001, 2013 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-25167398

RESUMO

The relatively small fraction of the spin of the proton carried by its quarks presents a major challenge to our understanding of the strong interaction. Traditional efforts to explore this problem have involved new and imaginative experiments and QCD based studies of the nucleon. We propose a new approach to the problem that exploits recent advances in lattice QCD. In particular, we extract values for the spin carried by the quarks in other members of the baryon octet in order to see whether the suppression observed for the proton is a general property or depends significantly on the baryon structure. We compare these results with the values for the spin fractions calculated within a model that includes the effects of confinement, relativity, gluon exchange currents, and the meson cloud required by chiral symmetry, finding a very satisfactory level of agreement given the precision currently attainable.

12.
Phys Rev Lett ; 107(9): 092004, 2011 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-21929231

RESUMO

Recent lattice QCD calculations have reported evidence for the existence of a bound state with strangeness -2 and baryon number 2 at quark masses somewhat higher than the physical values. By developing a description of the dependence of this binding energy on the up, down and strange quark masses that allows a controlled chiral extrapolation, we explore the hypothesis that this state is to be identified with the H dibaryon. Taking as input the recent results of the HAL and NPLQCD Collaborations, we show that the H dibaryon is likely to be unbound by 13±14 MeV at the physical point.

13.
Phys Rev Lett ; 93(18): 181802, 2004 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-15525151

RESUMO

We present a determination of the Cabibbo-Kobayashi-Maskawa parameter |V(us)| based on new measurements of the six largest K(L) branching fractions and semileptonic form factors by the KTeV (E832) experiment at Fermilab. We find |V(us)|=0.2252+/-0.0008(KTeV)+/-0.0021(ext), where the errors are from KTeV measurements and from external sources. We also use the measured branching fractions to determine the CP violation parameter |eta(+-)|=(2.228+/-0.005(KTeV)+/-0.009(ext))x10(-3).

14.
Phys Rev Lett ; 93(2): 021805, 2004 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-15323902

RESUMO

The KTeV/E799 experiment at Fermilab has searched for the rare kaon decay K(L)-->pi(0)e(+)e(-). This mode is expected to have a significant CP violating component. The measurement of its branching ratio could support the standard model or could indicate the existence of new physics. This Letter reports new results from the 1999-2000 data set. One event is observed with an expected background at 0.99+/-0.35 events. We set a limit on the branching ratio of 3.5x10(-10) at the 90% confidence level. Combining with the previous result based on the data set taken in 1997 yields the final KTeV result: BR(K(L)-->pi(0)e(+)e(-))<2.8x10(-10) at 90% C.L.

15.
Phys Rev Lett ; 90(14): 141801, 2003 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-12731905

RESUMO

The KTeV experiment at Fermilab has isolated a total of 132 events from the rare decay K(L)-->e+ e- mu+ mu-, with an estimated background of 0.8 events. The branching ratio of this mode is determined to be [2.69+/-0.24(stat)+/-0.12(syst)]x10(-9), with a radiative cutoff of M(2)(ee mu mu)/M(2)(K)>0.95. The first measurement using this mode of the parameter alpha from the D'Ambrosio-Isidori-Portolès (DIP) model of the K(L)gamma*gamma* vertex yields a result of -1.59+/-0.37, consistent with values obtained from other decay modes. Because of the limited statistics, no sensitivity is found to the DIP parameter beta. We use this decay mode to set limits on CP and lepton violation.

16.
Cell ; 107(4): 537-48, 2001 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-11719193

RESUMO

Mus81, a fission yeast protein related to the XPF subunit of ERCC1-XPF nucleotide excision repair endonuclease, is essential for meiosis and important for coping with stalled replication forks. These processes require resolution of X-shaped DNA structures known as Holliday junctions. We report that Mus81 and an associated protein Eme1 are components of an endonuclease that resolves Holliday junctions into linear duplex products. Mus81 and Eme1 are required during meiosis at a late step of meiotic recombination. The mus81 meiotic defect is rescued by expression of a bacterial Holliday junction resolvase. These findings constitute strong evidence that Mus81 and Eme1 are subunits of a nuclear Holliday junction resolvase.


Assuntos
Proteínas de Ligação a DNA/fisiologia , Endodesoxirribonucleases/fisiologia , Endonucleases/fisiologia , Proteínas de Schizosaccharomyces pombe/fisiologia , Schizosaccharomyces/genética , Sequência de Aminoácidos , Sítios de Ligação , Dano ao DNA , Reparo do DNA/fisiologia , DNA Fúngico/genética , DNA Fúngico/efeitos da radiação , Proteínas de Ligação a DNA/genética , Endodesoxirribonucleases/química , Endodesoxirribonucleases/genética , Endonucleases/genética , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/fisiologia , Resolvases de Junção Holliday , Substâncias Macromoleculares , Meiose/fisiologia , Modelos Genéticos , Modelos Moleculares , Dados de Sequência Molecular , Ligação Proteica , Proteínas Recombinantes de Fusão/fisiologia , Recombinação Genética/fisiologia , Proteínas de Saccharomyces cerevisiae , Schizosaccharomyces/enzimologia , Schizosaccharomyces/efeitos da radiação , Proteínas de Schizosaccharomyces pombe/química , Proteínas de Schizosaccharomyces pombe/genética , Homologia de Sequência de Aminoácidos , Especificidade por Substrato , Transfecção
18.
Water Sci Technol ; 43(5): 1-9, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11379119

RESUMO

Successful river water quality modelling requires the specification of an appropriate model structure and process formulation. Both must be related to the compartment structure of running water ecosystems including their longitudinal, vertical, and lateral zonation patterns. Furthermore, the temporal variability of abiotic boundary conditions may be important and must be incorporated by an appropriate choice of model parameters. A six-step decision procedure is proposed to achieve these objectives. The steps address the determination of the following model features: (1) temporal representation (dynamic or steady-state); (2) model dimensionality; (3) mixing; (4) advection; (5) reaction terms; and (6) boundary conditions. Numerical criteria based on process time constants and length scales provide a basis for these decisions.


Assuntos
Modelos Teóricos , Poluição da Água , Tomada de Decisões , Fatores de Tempo , Movimentos da Água
19.
Water Sci Technol ; 43(5): 11-30, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11379121

RESUMO

In this paper, biochemical process equations are presented as a basis for water quality modelling in rivers under aerobic and anoxic conditions. These equations are not new, but they summarise parts of the development over the past 75 years. The primary goals of the presentation are to stimulate communication among modellers and field-oriented researchers of river water quality and of wastewater treatment, to facilitate practical application of river water quality modelling, and to encourage the use of elemental mass balances for the derivation of stoichiometric coefficients of biochemical transformation processes. This paper is part of a series of three papers. In the first paper, the general modelling approach is described; in the present paper, the biochemical process equations of a complex model are presented; and in the third paper, recommendations are given for the selection of a reasonable submodel for a specific application.


Assuntos
Eutrofização , Modelos Teóricos , Poluição da Água , Bactérias Aeróbias , Hipóxia , Nitrogênio/metabolismo , Oxigênio/metabolismo , Esgotos
20.
Water Sci Technol ; 43(5): 31-40, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11379147

RESUMO

The new River Water Quality Model no. 1 introduced in the two accompanying papers by Shanahan et al. and Reichert et al. is comprehensive. Shanahan et al. introduced a six-step decision procedure to select the necessary model features for a certain application. This paper specifically addresses one of these steps, i.e. the selection of submodels of the comprehensive biochemical conversion model introduced in Reichert et al. Specific conditions for inclusion of one or the other conversion process or model component are introduced, as are some general rules that can support the selection. Examples of simplified models are presented.


Assuntos
Eutrofização , Modelos Teóricos , Poluição da Água , Fenômenos Bioquímicos , Bioquímica , Tomada de Decisões , Nitrogênio/metabolismo , Oxigênio/metabolismo , Esgotos
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