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1.
J Public Health (Oxf) ; 45(2): 379-388, 2023 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-35301537

RESUMO

BACKGROUND: Social participation is linked to better health and well-being. However, there is limited research on the individual and area-level predictors of participation. This study aims to determine the characteristics associated with participation, particularly the impact of community asset availability. METHODS: We used data from 34 582 adult respondents to the nationally representative Community Life Survey from 2013 to 2018. We measured social participation by reported participation in 15 types of groups. We used probit and negative binomial regression models and included a wide range of individual, household and area characteristics, and availability of 14 types of community assets. RESULTS: The following characteristics were associated with higher levels of participation: being female (+3.0 percentage points (p.p.) (95% CI 1.8 to 4.1p.p.), Black, Asian or Minority Ethnicity (+3.7p.p. (1.9 to 5.5p.p.)), homeownership (+4.1 p.p. (2.7 to 5.6p.p.)) and living in a rural area (+2.1p.p. (0.5 to 3.6p.p)). Respondents from the most deprived areas were less likely to participate than those in average deprivation areas (-3.9p.p. (-5.9 to -1.99p.p.)). Higher availability of community assets was associated with increased participation in groups. The effect of availability on participation varied by type of asset. CONCLUSION: Improving community assets infrastructure in high deprivation and urban areas would encourage more social participation in these areas.


Assuntos
Características da Família , Participação Social , Adulto , Humanos , Feminino , Masculino , Estudos Transversais , Inquéritos e Questionários , Inglaterra
2.
Diabet Med ; 37(9): 1536-1544, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32531074

RESUMO

AIM: To explore whether there are social inequalities in non-diabetic hyperglycaemia (NDH) and in transitions to type 2 diabetes mellitus and NDH low-risk status in England. METHODS: Some 9143 men and women aged over 50 years were analysed from waves 2, 4, 6 and 8 (2004-2016) of the English Longitudinal Study of Ageing (ELSA). Participants were categorized as: NDH 'low-risk' [HbA1c < 42 mmol/mol (< 6.0%)], NDH [HbA1c 42-47 mmol/mol (6.0-6.4%)] and type 2 diabetes [HbA1c > 47 mmol/mol (> 6.4%)]. Logistic regression models estimated the association between sociodemographic characteristics and NDH, and the transitions from NDH to diagnosed or undiagnosed type 2 diabetes and low-risk status in future waves. RESULTS: NDH was more prevalent in older participants, those reporting a disability, those living in deprived areas and in more disadvantaged social classes. Older participants with NDH were less likely to progress to undiagnosed type 2 diabetes [odds ratio (OR) 0.27, 95% confidence interval (CI) 0.08, 0.96]. NDH individuals with limiting long-standing illness (OR 1.72, 95% CI 1.16, 2.53), who were economically inactive (OR 1.60, 95% CI 1.02, 2.51) or from disadvantaged social classes (OR 1.63, 95% CI 1.02, 2.61) were more likely to progress to type 2 diabetes. Socially disadvantaged individuals were less likely (OR 0.64, 95% CI 0.41, 0.98) to progress to NDH low-risk status. CONCLUSIONS: There were socio-economic differences in NDH prevalence, transition to type 2 diabetes and transition to NDH low-risk status. Disparities in transitions included the greater likelihood of disadvantaged social groups with NDH developing type 2 diabetes and greater likelihood of advantaged social groups with NDH becoming low-risk. These socio-economic differences should be taken into account when targeting prevention initiatives.


Assuntos
Diabetes Mellitus Tipo 2/epidemiologia , Status Econômico , Emprego/estatística & dados numéricos , Disparidades nos Níveis de Saúde , Hiperglicemia/epidemiologia , Estado Pré-Diabético/epidemiologia , Classe Social , Idoso , Diabetes Mellitus Tipo 2/metabolismo , Progressão da Doença , Inglaterra/epidemiologia , Feminino , Hemoglobinas Glicadas/metabolismo , Humanos , Hiperglicemia/metabolismo , Masculino , Pessoa de Meia-Idade , Estado Pré-Diabético/metabolismo , Fatores de Risco
3.
Community Dent Health ; 37(4): 287-292, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-33026721

RESUMO

OBJECTIVE: The study sought to explore the consent rate and associated potential bias across a cohort in a large longitudinal population based study. RESEARCH DESIGN: Data were taken from a study designed to examine the effects of the reintroduction of community water fluoridation on children's oral health over a five-year period. Children were recruited from a fluoridated and non-fluoridated area in Cumbria, referred to as Group 1 and Group 2. RESULTS: Data were available for 3138 individuals. The consent rate was 12.91 percentage points lower in Group 2 than Group 1 (95% CI -16.27 to -9.56, p⟨0.001). The population in Group 2 was more deprived (higher Index of Multiple Deprivation (IMD)) than Group 1 before consent was taken. Consent was not associated with deprivation in either group. CONCLUSION: The cohort appeared to be unaffected by IMD-related non-consent. However there was a difference in consent rate between the two groups. With the population in Group 1 being more deprived than Group 2, it will be important to incorporate these differences into the analysis at the end of this longitudinal study.


Assuntos
Cárie Dentária , Criança , Índice CPO , Fluoretação , Humanos , Consentimento Livre e Esclarecido , Estudos Longitudinais
4.
Br J Surg ; 104(6): 769-776, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28195304

RESUMO

BACKGROUND: Surgical wound complications remain a major cause of morbidity, leading to higher costs and reduced quality of life. Although psychological health is widely considered to affect wound healing, the evidence on wound outcomes after surgery is mixed. Studies generally focus on small samples of patients undergoing a specific procedure and have limited statistical power. METHODS: This study investigated the relationship between three different measures of anxiety and/or depression and seven adverse surgical outcomes using observational data collected before and after surgery between 2009 and 2011. A wide range of confounding factors was adjusted for, including patient demographics, physical co-morbidities, health-related behaviours, month of operation, procedure complexity and treating hospital. RESULTS: The estimation sample included 176 827 patients undergoing 59 410 hip replacements, 64 145 knee replacements, 38 328 hernia repairs and 14 944 varicose vein operations. Patients with moderate anxiety or depression had an increased probability of wound complications after a hip replacement (odds ratio (OR) 1·17, 95 per cent c.i. 1·11 to 1·24). They were more likely to be readmitted for a wound complication (OR 1·20, 1·02 to 1·41) and had an increased duration of hospital stay by 0·19 (95 per cent c.i. 0·15 to 0·24) days. Estimated associations were consistent across all four types of operation and for each measure of anxiety and/or depression. CONCLUSION: Preoperative psychological health is a significant risk factor for adverse wound outcomes after surgery for four of the procedures most commonly performed in England.


Assuntos
Transtornos de Ansiedade/complicações , Transtorno Depressivo/complicações , Complicações Pós-Operatórias/psicologia , Ferida Cirúrgica/psicologia , Cicatrização/fisiologia , Adolescente , Adulto , Idoso , Artroplastia de Quadril/psicologia , Artroplastia do Joelho/psicologia , Criança , Feminino , Herniorrafia/psicologia , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Readmissão do Paciente/estatística & dados numéricos , Cuidados Pré-Operatórios , Fatores de Risco , Varizes/psicologia , Varizes/cirurgia , Adulto Jovem
5.
J Environ Manage ; 165: 106-116, 2016 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-26413804

RESUMO

Trees are very effective at capturing both gaseous and particulate pollutants from the atmosphere. But while studies have often focussed on PM and NOx in the urban environment, little research has been carried out on the tree effect of capturing gaseous emissions of ammonia in the rural landscape. To examine the removal or scavenging of ammonia by trees a long-range atmospheric model (FRAME) was used to compare two strategies that could be used in emission reduction policies anywhere in the world where nitrogen pollution from agriculture is a problem. One strategy was to reduce the emission source strength of livestock management systems by implementing two 'tree-capture' systems scenarios - tree belts downwind of housing and managing livestock under trees. This emission reduction can be described as an 'on-farm' emission reduction policy, as ammonia is 'stopped' from dispersion outside the farm boundaries. The second strategy was to apply an afforestation policy targeting areas of high ammonia emission through two planting scenarios of increasing afforestation by 25% and 50%. Both strategies use trees with the aim of intercepting NH3 emissions to protect semi-natural areas. Scenarios for on-farm emission reductions showed national reductions in nitrogen deposition to semi-natural areas of 0.14% (0.2 kt N-NHx) to 2.2% (3.15 kt N-NHx). Scenarios mitigating emissions from cattle and pig housing gave the highest reductions. The afforestation strategy showed national reductions of 6% (8.4 kt N-NHx) to 11% (15.7 kt N-NHx) for 25% and 50% afforestation scenarios respectively. Increased capture by the planted trees also showed an added benefit of reducing long range effects including a decrease in wet deposition up to 3.7 kt N-NHx (4.6%) and a decrease in export from the UK up to 8.3 kt N-NHx (6.8%).


Assuntos
Amônia/análise , Criação de Animais Domésticos , Gado , Modelos Teóricos , Árvores , Animais , Atmosfera , Bovinos , Ecossistema , Poluição Ambiental/prevenção & controle , Gases , Nitrogênio/análise , Suínos
6.
Int J Clin Pract ; 68(7): 882-9, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24589010

RESUMO

INTRODUCTION AND PURPOSE: The need for aggressive efforts to help tobacco users quit remains a healthcare priority. Brief interventions delivered in the healthcare environment continue to be a valuable component of a comprehensive tobacco control policy. Unfortunately, such treatments are offered less often than desired, and quality is variable. Previous research has demonstrated the value of training experiences in increasing treatment availability, quality, as well as improving clinical outcomes. Less is known about how specific clinical activities and other features are impacted as a function of training. These issues were explored within the context of a standardised 5A's (ASK, ADVISE, ASSESS, ASSIST, ARRANGE) brief intervention training program. METHODS: A variety of healthcare providers participated in this study. Survey methodology was employed to collect Practice Behaviour, Self-Efficacy and Attitude ratings at pretraining, post training and 6-month follow-up. Linear mixed effects models were used to evaluate primary outcomes, and linear regression to explore the relationships among clinical variables. RESULTS: Pretraining data suggested overall modest levels of tobacco treatment activity, with limited direct intervention (ASSIST) or follow-up (ARRANGE) efforts. The training experience was shown to have a substantial and sustained impact on 5A's Practice Behaviour ratings, and other clinical indicators (all Pre vs. Post and Pre vs. Follow-up comparisons p < 0.001). Self-Efficacy at post training predicted practice behaviours at follow-up (for ADVISE, ASSESS, ASSIST and ARRANGE: all p's < 0.05). CONCLUSIONS: The value of a structured training experience was confirmed, and findings served to clarify the specific nature of training program impact.


Assuntos
Pessoal de Saúde/psicologia , Nicotiana/efeitos adversos , Abandono do Hábito de Fumar/psicologia , Fatores de Tempo , Atitude do Pessoal de Saúde , Comportamento , Atenção à Saúde/métodos , Humanos , Autoeficácia , Abandono do Hábito de Fumar/métodos , Inquéritos e Questionários
7.
Am J Transplant ; 13(5): 1327-35, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23463950

RESUMO

In contrast to traditional static cold preservation of donor livers, normothermic machine perfusion may reduce preservation injury, improve graft viability and potentially allows ex vivo assessment of graft viability before transplantation. We have studied the feasibility of normothermic machine perfusion in four discarded human donor livers. Normothermic machine perfusion consisted of pressure and temperature controlled pulsatile perfusion of the hepatic artery and continuous portal perfusion for 6 h. Two hollow fiber membrane oxygenators provided oxygenation of the perfusion fluid. Biochemical markers in the perfusion fluid reflected minimal hepatic injury and improving function. Lactate levels decreased to normal values, reflecting active metabolism by the liver (mean lactate 10.0 ± 2.3 mmol/L at 30 min to 2.3 ± 1.2 mmol/L at 6 h). Bile production was observed throughout the 6 h perfusion period (mean rate 8.16 ± 0.65 g/h after the first hour). Histological examination before and after 6 h of perfusion showed well-preserved liver morphology without signs of additional hepatocellular ischemia, biliary injury or sinusoidal damage. In conclusion, this study shows that normothermic machine perfusion of human donor livers is technically feasible. It allows assessment of graft viability before transplantation, which opens new avenues for organ selection, therapeutic interventions and preconditioning.


Assuntos
Sobrevivência de Enxerto , Precondicionamento Isquêmico/métodos , Transplante de Fígado , Fígado/irrigação sanguínea , Preservação de Órgãos/métodos , Perfusão/métodos , Adulto , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Temperatura
8.
Horm Metab Res ; 45(6): 449-55, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23426860

RESUMO

The prevalence and prognostic importance of diastolic dysfunction in type 2 diabetes has only recently been appreciated. We tested the hypothesis that in insulin treated type 2 diabetes (D), carbohydrate consumption induces oxidative stress resulting in further impairment of diastolic function beyond structural myocardial stiffness. The effects of a pure carbohydrate breakfast (48 g) on oxidative stress and cardiac function were studied in the fasting and postmeal states in subjects without hypertension or overt cardiac disease (moderately well controlled D, n=21 and controls without D, n=20). Studied variables included systolic and early diastolic (E') myocardial velocities, traditional metabolic and hemodynamic parameters, serum nitrotyrosine, and sVCAM-1. In D compared to control subjects, the postmeal increase (∆) in glucose (1.44±2.78 vs. 0.11±0.72 mmol/l, p=0.04) and ∆nitrotyrosine (0.34±0.37 vs. -0.23±0.47 nM/l, p<0.001) were significantly higher. sVCAM-1 was higher in fasting and postmeal (p=0.02). E' was significantly lower in postmeal (7.3±1.3 vs. 9.6±1.3 cm/s, p<0.001) and fasting (p<0.001) whereas the rate pressure product was significantly higher (9 420±1 118 vs. 7 705±1 871 mm Hg/min, p<0.001). Multivariable regression models of the pooled data demonstrated that independent predictors for postmeal E' were ∆nitrotyrosine and septal thickness (R² 0.466) and for fasting E' age, ∆nitrotyrosine, and septal thickness (R² 0.400). In insulin requiring type 2 diabetes, carbohydrate consumption may induce oxidative stress that is associated with worsening diastolic function, indicating that this metabolic factor is an important determinant of diastolic dysfunction in the diabetic heart beyond the increase in structural myocardial stiffness.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/fisiopatologia , Diástole , Carboidratos da Dieta/metabolismo , Insulina/uso terapêutico , Estresse Oxidativo , Adulto , Idoso , Idoso de 80 Anos ou mais , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diástole/efeitos dos fármacos , Carboidratos da Dieta/efeitos adversos , Feminino , Coração/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Período Pós-Prandial , Estudos Prospectivos
9.
Phys Rev Lett ; 109(18): 185502, 2012 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-23215295

RESUMO

The availability of ultrafast pulses of coherent hard x rays from the Linac Coherent Light Source opens new opportunities for studies of atomic-scale dynamics in amorphous materials. Here, we show that single ultrafast coherent x-ray pulses can be used to observe the speckle contrast in the high-angle diffraction from liquid Ga and glassy Ni(2)Pd(2)P and B(2)O(3). We determine the thresholds above which the x-ray pulses disturb the atomic arrangements. Furthermore, high contrast speckle is observed in scattering patterns from the glasses integrated over many pulses, demonstrating that the source and optics are sufficiently stable for x-ray photon correlation spectroscopy studies of dynamics over a wide range of time scales.


Assuntos
Vidro/química , Modelos Teóricos , Difração de Raios X/métodos , Compostos de Boro/química , Gálio/química , Níquel/química , Paládio/química , Fósforo/química , Fótons
10.
BMC Health Serv Res ; 12: 43, 2012 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-22340710

RESUMO

BACKGROUND: To examine the association between rurality and health in Scotland, after adjusting for differences in individual and practice characteristics. DESIGN: Mortality and hospital record data linked to two cross sectional health surveys. SETTING: Respondents in the community-based 1995 and 1998 Scottish Health Survey who consented to record-linkage follow-up. MAIN OUTCOME MEASURES: Hypertension, all-cause premature mortality, total hospital stays and admissions due to coronary heart disease (CHD). RESULTS: Older age and lower social class were strongly associated with an increased risk of each of the four health outcomes measured. After adjustment for individual and practice characteristics, no consistent pattern of better or poorer health in people living in rural areas was found, compared to primary cities. However, individuals living in remote small towns had a lower risk of a hospital admission for CHD and those in very remote rural had lower mortality, both compared with those living in primary cities. CONCLUSION: This study has shown how linked data can be used to explore the possible influence of area of residence on health. We were unable to find a consistent pattern that people living in rural areas have materially different health to that of those living in primary cities. Instead, we found stronger relationships between compositional determinants (age, gender and socio-economic status) and health than contextual factors (including rurality).


Assuntos
Tempo de Internação/estatística & dados numéricos , Admissão do Paciente/estatística & dados numéricos , Saúde da População Rural/estatística & dados numéricos , Saúde da População Urbana/estatística & dados numéricos , Adolescente , Adulto , Distribuição por Idade , Idoso , Causas de Morte , Doença das Coronárias/epidemiologia , Feminino , Inquéritos Epidemiológicos , Humanos , Hipertensão/epidemiologia , Masculino , Registro Médico Coordenado , Pessoa de Meia-Idade , Mortalidade Prematura , Características de Residência , Escócia/epidemiologia , Distribuição por Sexo , Fatores Socioeconômicos , Adulto Jovem
11.
Eur Phys J C Part Fields ; 82(10): 930, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36277417

RESUMO

Fast interpolation-grid frameworks facilitate an efficient and flexible evaluation of higher-order predictions for any choice of parton distribution functions or value of the strong coupling α s . They constitute an essential tool for the extraction of parton distribution functions and Standard Model parameters, as well as studies of the dependence of cross sections on the renormalisation and factorisation scales. The APPLfast project provides a generic interface between the parton-level Monte Carlo generator and both the APPLgrid and the fastNLO libraries for the grid interpolation. The extension of the project to include hadron-hadron collider processes at next-to-next-to-leading order in perturbative QCD is presented, together with an application for jet production at the LHC.

12.
Biol Lett ; 7(1): 146-9, 2011 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-20685698

RESUMO

Soft-bodied taxa comprise an important component of the extant lophophorate fauna, but convincing fossils of soft-bodied lophophorates are extremely rare. A small fossil lophophorate, attached to a brachiopod dorsal valve, is described from the Silurian (Wenlock Series) Herefordshire Lagerstätte of England. This unmineralized organism was bilaterally symmetrical and comprised a subconical body attached basally to the host and partially enclosed by a broad 'hood'; the body bore a small, coiled lophophore. Where the hood attached laterally, there is a series of transverse ridges and furrows. The affinities of this organism probably lie with Brachiopoda; the hood is interpreted as the homologue of a dorsal valve/mantle lobe, and the attachment as the homologue of the ventral valve and/or pedicle. The ridges are arranged in a manner that suggests constructional serial repetition, indicating that they are unlikely to represent mantle canals. Extant brachiopods are not serially structured, but morphological and molecular evidence suggests that their ancestors were. The new organism may belong to the brachiopod stem group, and might also represent a significant element of the Palaeozoic lophophorate fauna.


Assuntos
Fósseis , Invertebrados/classificação , Animais , Inglaterra
13.
J Med Genet ; 47(10): 677-85, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20577008

RESUMO

OBJECTIVE: Women who have low cobalamin (vitamin B(12)) levels are at increased risk for having children with neural tube defects (NTDs). The transcobalamin II receptor (TCblR) mediates uptake of cobalamin into cells. Inherited variants in the TCblR gene as NTD risk factors were evaluated. METHODS: Case-control and family-based tests of association were used to screen common variation in TCblR as genetic risk factors for NTDs in a large Irish group. A confirmatory group of NTD triads was used to test positive findings. RESULTS: 2 tightly linked variants associated with NTDs in a recessive model were found: TCblR rs2336573 (G220R; p(corr)=0.0080, corrected for multiple hypothesis testing) and TCblR rs9426 (p(corr)=0.0279). These variants were also associated with NTDs in a family-based test before multiple test correction (log-linear analysis of a recessive model: rs2336573 (G220R; RR=6.59, p=0.0037) and rs9426 (RR=6.71, p=0.0035)). A copy number variant distal to TCblR and two previously unreported exonic insertion-deletion polymorphisms were described. CONCLUSIONS: TCblR rs2336573 (G220R) and TCblR rs9426 represent a significant risk factor in NTD cases in the Irish population. The homozygous risk genotype was not detected in nearly 1000 controls, indicating that this NTD risk factor may be of low frequency and high penetrance. 9 other variants are in perfect linkage disequilibrium with the associated single nucleotide polymorphisms. Additional work is required to identify the disease-causing variant. Our data suggest that variation in TCblR plays a role in NTD risk and that these variants may modulate cobalamin metabolism.


Assuntos
Predisposição Genética para Doença , Defeitos do Tubo Neural/genética , Polimorfismo Genético , Receptores de Superfície Celular/genética , Alelos , Estudos de Casos e Controles , Estudos de Coortes , Família , Feminino , Frequência do Gene , Genótipo , Humanos , Irlanda , Masculino , Receptores de Superfície Celular/metabolismo , Fatores de Risco , Transcobalaminas/metabolismo
14.
Diabetologia ; 53(6): 1033-45, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20349347

RESUMO

Cardiac disease in diabetes mellitus and in the metabolic syndrome consists of both vascular and myocardial abnormalities. The latter are characterised predominantly by diastolic dysfunction, which has been difficult to evaluate in spite of its prevalence. While traditional Doppler echocardiographic parameters enable only semiquantitative assessment of diastolic function and cannot reliably distinguish perturbations in loading conditions from altered diastolic functions, new technologies enable detailed quantification of global and regional diastolic function. The most readily available technique for the quantification of subclinical diastolic dysfunction is tissue Doppler imaging, which has been integrated into routine contemporary clinical practice, whereas cine magnetic resonance imaging (CMR) remains a promising complementary research tool for investigating the molecular mechanisms of the disease. Diastolic function is reported to vary linearly with age in normal persons, decreasing by 0.16 cm/s each year. Diastolic function in diabetes and the metabolic syndrome is determined by cardiovascular risk factors that alter myocardial stiffness and myocardial energy availability/bioenergetics. The latter is corroborated by the improvement in diastolic function with improvement in metabolic control of diabetes by specific medical therapy or lifestyle modification. Accordingly, diastolic dysfunction reflects the structural and metabolic milieu in the myocardium, and may allow targeted therapeutic interventions to modulate cardiac metabolism to prevent heart failure in insulin resistance and diabetes.


Assuntos
Doenças Cardiovasculares/complicações , Doenças Cardiovasculares/diagnóstico , Diabetes Mellitus Tipo 2/complicações , Síndrome Metabólica/complicações , Doenças Cardiovasculares/fisiopatologia , Diabetes Mellitus Tipo 2/fisiopatologia , Humanos , Síndrome Metabólica/fisiopatologia , Prognóstico , Fatores de Risco
15.
Environ Monit Assess ; 161(1-4): 11-27, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19184491

RESUMO

A conditional time-averaged gradient (COTAG) system has been developed to provide direct long-term (weekly to monthly) average flux gradient measurements for a range of trace gases, between land and atmosphere. Over daily periods, atmospheric conditions can range from high stability, where the vertical gradients of ambient concentration are enhanced due to very small diffusivity, to highly unstable conditions, in which concentration gradients are small due to the intense turbulent activity of the surface layer. The large vertical gradients generated by high stability would bias the estimate of the actual flux: to avoid this, the COTAG system samples conditionally, within a carefully refined range of stability. A comparison with a continuous flux gradient system suggested that the removal of stable conditions from the sampling period does not substantially modify the evaluation of the long-term fluxes.


Assuntos
Monitoramento Ambiental/economia , Monitoramento Ambiental/métodos , Compostos de Amônio Quaternário/análise , Dióxido de Enxofre/análise , Modelos Teóricos
16.
Phys Rev E ; 102(3-1): 032802, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33076025

RESUMO

The dewetting dynamics of a supported bilayer polymer thin film on a solid substrate is investigated using grazing incidence x-ray photon correlation spectroscopy. We find that the top layer dewets via the spinodal mechanism. The kinetics of the dewetting is studied by monitoring the time evolution of the surface diffuse x-ray scattering intensity. We study the time evolution of fluctuations about the average surface structure by measuring the two-time x-ray intensity fluctuation correlation functions. Using these two-time correlation functions we quantify the crossover from early-time diffusive dynamics to hydrodynamics. The early diffusive regime satisfies dynamic universality. The two-time correlation functions also quantify the onset of hydrodynamic effects. The hydrodynamic regime is observed during the spinodal dewetting process as these interactions are not screened.

17.
Philos Trans R Soc Lond B Biol Sci ; 374(1788): 20190210, 2019 12 23.
Artigo em Inglês | MEDLINE | ID: mdl-31679492

RESUMO

How does past evolutionary performance impact future evolutionary performance? This is an important question not just for macroevolutionary biologists who wish to chart the phenomena that describe deep-time changes in biodiversity but also for conservation biologists, as evolutionarily distinct species-which may be deemed 'low-performing' in our current era-are increasingly the focus of conservation efforts. Contrasting hypotheses exist to account for the history and future of evolutionarily distinct species: on the one hand, they may be relicts of large radiations, potentially 'doomed' to extinction; or they may be slow-evolving, 'living fossils', likely neither to speciate nor go extinct; or they may be seeds of future radiations. Here, we attempt to test these hypotheses in Mammalia by combining a molecular phylogenetic supertree with fossil record occurrences and measuring change in evolutionary distinctness (ED) at different time slices. With these time slices, we modelled future ED as a function of past ED. We find that past evolutionary performance does indeed have an impact on future evolutionary performance: the most evolutionarily isolated clades tend to become more evolutionarily distinct with time, indicating that low-performing clades tend to remain low-performing throughout their evolutionary history. This article is part of a discussion meeting issue 'The past is a foreign country: how much can the fossil record actually inform conservation?'


Assuntos
Evolução Biológica , Fósseis/anatomia & histologia , Mamíferos/anatomia & histologia , Mamíferos/genética , Animais , Biodiversidade , Extinção Biológica , Modelos Biológicos , Filogenia
18.
Sci Total Environ ; 653: 698-704, 2019 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-30759595

RESUMO

Although it is generally accepted that δ15N in lichen reflects predominating N isotope sources in the environment, confirmation of the direct correlation between lichen δ15N and atmospheric δ15N is still missing, especially under field conditions with most confounding factors controlled. To fill this gap and investigate the response of lichens with different tolerance to atmospheric N deposition, thalli of the sensitive Evernia prunastri and the tolerant Xanthoria parietina were exposed for ten weeks to different forms and doses of N in a field manipulation experiment where confounding factors were minimized. During this period, several parameters, namely total N, δ15N and chlorophyll a fluorescence, were measured. Under the experimental conditions, δ15N in lichens quantitatively responded to the δ15N of released gaseous ammonia (NH3). Although a high correlation between the isotopic signatures in lichen tissue and supplied N was found both in tolerant and sensitive species, chlorophyll a fluorescence indicated that the sensitive species very soon lost its photosynthetic functionality with increasing N availability. The most damaging response to the different N chemical forms was observed with dry deposition of NH3, although wet deposition of ammonium ions had a significant observable physiological impact. Conversely, there was no significant effect of nitrate ions on chlorophyll a fluorescence, implying differential sensitivity to dry deposition versus wet deposition and to ammonium versus nitrate in wet deposition. Evernia prunastri was most sensitive to NH3, then NH4+, with lowest sensitivity to NO3-. Moreover, these results confirm that lichen δ15N can be used to indicate the δ15N of atmospheric ammonia, providing a suitable tool for the interpretation of the spatial distribution of NH3 sources in relation to their δ15N signal.


Assuntos
Poluentes Atmosféricos/análise , Amônia/análise , Monitoramento Ambiental/métodos , Líquens/química , Isótopos de Nitrogênio/análise , Poluentes Atmosféricos/toxicidade , Amônia/toxicidade , Clorofila A/metabolismo , Líquens/efeitos dos fármacos , Líquens/fisiologia , Modelos Teóricos , Nitratos/análise , Nitratos/toxicidade , Fotossíntese/efeitos dos fármacos , Especificidade da Espécie
19.
Equine Vet J ; 51(6): 840-845, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31009100

RESUMO

BACKGROUND: Accelerometry is an accepted means of quantifying human physical activity. Quantitative physical activity tracking could be beneficial for studies into equine health and disease prevention, for example in relation to obesity management. OBJECTIVES: Validate accelerometer use in grazing horses, determine between-day repeatability, and assess the effects of pasture size on time budget (i.e. duration in each activity category). STUDY DESIGN: Proof of concept. METHODS: Accelerometers (ActiGraph) were positioned at the poll. Horses underwent 5 min of observed activity in three categories: standing, grazing and ambulating. Receiver-operating characteristic curve analysis, used on ten second data epochs, calculated cut points between the activities. A 20-day study was then undertaken on 6 horses at pasture. Time in each category (per day) was deduced; a Mann Whitney U test was performed to compare standard vs. small paddock and day vs. night turn out. RESULTS: Cut-off values with the optimum sensitivity (94.7-97.7%) and specificity (94.7-96.8%) were found to be <127.6 counts for standing, 127.6-702.7 counts for grazing and >702.7 counts for ambulating. Repeatability was analysed descriptively: Median (IQR) of the between-day difference in minutes standing, grazing and ambulating were 46.9 (21.3-87.9), 77.3 (40.2-124.5) and 15.6 (6.8-40.2) respectively. Median times standing and ambulating were significantly different between standard and small paddocks: standing: 8.7 vs. 10.3 h (P<0.001); ambulating: 55.7 vs. 39.6 min (P = 0.002). There was no significant difference in the median time spent grazing. There were significant differences between day and night: standing: 32.95% vs. 50.97% (P = 0.001), grazing: 60.81% vs. 46.77% (P<0.001) and ambulating: 4.57% vs. 2.40% (P<0.001). MAIN LIMITATIONS: Small sample size and lack of cross-validation of cut-off points on independent, 'unseen' data. CONCLUSIONS: Accelerometry can differentiate standing, grazing and ambulating in horses. Our proof-of-concept study demonstrates modifying pasture size influences activity budgets; opening avenues into studying obesity management.


Assuntos
Acelerometria/veterinária , Criação de Animais Domésticos , Cavalos/fisiologia , Monitorização Fisiológica/veterinária , Atividade Motora/fisiologia , Animais , Feminino , Masculino , Monitorização Fisiológica/instrumentação
20.
Eur Phys J C Part Fields ; 79(10): 845, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31807114

RESUMO

The extension of interpolation-grid frameworks for perturbative QCD calculations at next-to-next-to-leading order (NNLO) is presented for deep inelastic scattering (DIS) processes. A fast and flexible evaluation of higher-order predictions for any a posteriori choice of parton distribution functions (PDFs) or value of the strong coupling constant is essential in iterative fitting procedures to extract PDFs and Standard Model parameters as well as for a detailed study of the scale dependence. The APPLfast project, described here, provides a generic interface between the parton-level Monte Carlo program NNLOjet and both the APPLgrid and fastNLO libraries for the production of interpolation grids at NNLO accuracy. Details of the interface for DIS processes are presented together with the required interpolation grids at NNLO, which are made available. They cover numerous inclusive jet measurements by the H1 and ZEUS experiments at HERA. An extraction of the strong coupling constant is performed as an application of the use of such grids and a best-fit value of α s ( M Z ) = 0.1170 ( 15 ) exp ( 25 ) th is obtained using the HERA inclusive jet cross section data.

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