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1.
Phys Rev Lett ; 132(21): 216502, 2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38856271

RESUMO

Using spin-echo nuclear magnetic resonance in the model transverse field Ising system TmVO_{4}, we show that low frequency quantum fluctuations at the quantum critical point have a very different effect on ^{51}V nuclear spins than classical low-frequency noise or fluctuations that arise at a finite temperature critical point. Spin echoes filter out the low-frequency classical noise but not the quantum fluctuations. This allows us to directly visualize the quantum critical fan and demonstrate the persistence of quantum fluctuations at the critical coupling strength in TmVO_{4} to high temperatures in an experiment that remains transparent to finite temperature classical phase transitions. These results show that while dynamical decoupling schemes can be quite effective in eliminating classical noise in a qubit, a quantum critical environment may lead to rapid entanglement and decoherence.

2.
Proc Natl Acad Sci U S A ; 117(36): 22293-22302, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32839321

RESUMO

During austral summer field seasons between 1999 and 2018, we sampled at 91 locations throughout southern Victoria Land and along the Transantarctic Mountains for six species of endemic microarthropods (Collembola), covering a latitudinal range from 76.0°S to 87.3°S. We assembled individual mitochondrial cytochrome c oxidase subunit 1 (COI) sequences (n = 866) and found high levels of sequence divergence at both small (<10 km) and large (>600 km) spatial scales for four of the six Collembola species. We applied molecular clock estimates and assessed genetic divergences relative to the timing of past glacial cycles, including collapses of the West Antarctic Ice Sheet (WAIS). We found that genetically distinct lineages within three species have likely been isolated for at least 5.54 My to 3.52 My, while the other three species diverged more recently (<2 My). We suggest that Collembola had greater dispersal opportunities under past warmer climates, via flotation along coastal margins. Similarly increased opportunities for dispersal may occur under contemporary climate warming scenarios, which could influence the genetic structure of extant populations. As Collembola are a living record of past landscape evolution within Antarctica, these findings provide biological evidence to support geological and glaciological estimates of historical WAIS dynamics over the last ca 5 My.


Assuntos
Variação Genética , Invertebrados/genética , Solo , Animais , Regiões Antárticas , Mudança Climática , Camada de Gelo , Estações do Ano
3.
J Interprof Care ; 37(1): 118-130, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35341438

RESUMO

Improving the productivity of the allied health workforce is a global priority in response to the increasing incidence of chronic disease, associated healthcare costs, and insufficient workforce volume. Team-based healthcare, specifically allied health transdisciplinary teams, might be a solution to improve the utilization of workforce while maintaining high-quality and value-based healthcare. Allied health transdisciplinary teams can be a valuable solution in settings where care is delivered by different allied health professionals. Transdisciplinary teams embrace overlapping skills and blur traditional professional boundaries, allowing one professional to deliver certain aspects of care without eroding the skills and knowledge that each profession offers. The objective of this scoping review is to systematically examine and map the characteristics, outcomes, facilitators, and barriers of contemporary allied health transdisciplinary models of care that have been implemented in hospital settings. The scoping review was guided by the Joanna Briggs Institute methodology and reported in line with the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). Three screening rounds were completed by two independent reviewers. Included sources were synthesized using descriptive and tabular analysis. Nine studies that evaluated hospital-based allied health transdisciplinary teams were included. One study was a randomized controlled trial, five were experimental quantitative studies, two utilized qualitative analyses, and one was a conference abstract. Most studies reported improvements in time-efficiency, quality of care, and positive stakeholder perceptions. One study reported labor and capital cost savings. Barriers and facilitators of transdisciplinary teams were categorized by the authors as person/interpersonal, workflow, organizational or implementation factors. This review presents some evidence that demonstrates the potential of hospital-based allied health transdisciplinary teams, however high-quality evidence is scarce. Further primary research should focus on stakeholder perceptions, and labor and capital cost outcomes.


Assuntos
Atenção à Saúde , Relações Interprofissionais , Humanos , Pessoal Técnico de Saúde , Hospitais , Ensaios Clínicos Controlados Aleatórios como Assunto
4.
Rhinology ; 60(3): 207-217, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35398877

RESUMO

BACKGROUND: Sudden smell loss is a specific early symptom of COVID-19, which, prior to the emergence of Omicron, had estimated prevalence of ~40% to 75%. Chemosensory impairments affect physical and mental health, and dietary behavior. Thus, it is critical to understand the rate and time course of smell recovery. The aim of this cohort study was to characterize smell function and recovery up to 11 months post COVID-19 infection. METHODS: This longitudinal survey of individuals suffering COVID-19-related smell loss assessed disease symptoms and gustatory and olfactory function. Participants (n=12,313) who completed an initial survey (S1) about respiratory symptoms, chemosensory function and COVID-19 diagnosis between April and September 2020, were invited to complete a follow-up survey (S2). Between September 2020 and February 2021, 27.5% participants responded (n=3,386), with 1,468 being diagnosed with COVID-19 and suffering co-occurring smell and taste loss at the beginning of their illness. RESULTS: At follow-up (median time since COVID-19 onset ~200 days), ~60% of women and ~48% of men reported less than 80% of their pre-illness smell ability. Taste typically recovered faster than smell, and taste loss rarely persisted if smell recovered. Prevalence of parosmia and phantosmia was ~10% of participants in S1 and increased substantially in S2: ~47% for parosmia and ~25% for phantosmia. Persistent smell impairment was associated with more symptoms overall, suggesting it may be a key marker of long-COVID illness. The ability to smell during COVID-19 was rated slightly lower by those who did not eventually recover their pre-illness ability to smell at S2. CONCLUSIONS: While smell ability improves for many individuals who lost it during acute COVID-19, the prevalence of parosmia and phantosmia increases substantially over time. Olfactory dysfunction is associated with broader persistent symptoms of COVID-19, and may last for many months following acute COVID-19. Taste loss in the absence of smell loss is rare. Persistent qualitative smell symptoms are emerging as common long-term sequelae; more research into treatment options is strongly warranted given that even conservative estimates suggest millions of individuals may experience parosmia following COVID-19. Healthcare providers worldwide need to be prepared to treat post COVID-19 secondary effects on physical and mental health.


Assuntos
Ageusia , COVID-19 , Transtornos do Olfato , Masculino , Humanos , Feminino , COVID-19/complicações , Olfato , Anosmia/etiologia , SARS-CoV-2 , Estudos de Coortes , Teste para COVID-19 , Seguimentos , Síndrome de COVID-19 Pós-Aguda , Transtornos do Olfato/epidemiologia , Transtornos do Olfato/etiologia , Transtornos do Olfato/diagnóstico
5.
Br J Surg ; 108(3): 315-325, 2021 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-33760065

RESUMO

BACKGROUND: Primary endocrine therapy may be an alternative treatment for less fit women with oestrogen receptor (ER)-positive breast cancer. This study compared quality-of-life (QoL) outcomes in older women treated with surgery or primary endocrine therapy. METHODS: This was a multicentre, prospective, observational cohort study of surgery or primary endocrine therapy in women aged over 70 years with operable breast cancer. QoL was assessed using European Organisation for Research and Treatment of cancer QoL questionnaires QLQ-C30, -BR23, and -ELD14, and the EuroQol Five Dimensions 5L score at baseline, 6 weeks, and 6, 12, 18, and 24 months. Propensity score matching was used to adjust for baseline variation in health, fitness, and tumour stage. RESULTS: The study recruited 3416 women (median age 77 (range 69-102) years) from 56 breast units. Of these, 2979 (87.2 per cent) had ER-positive breast cancer; 2354 women had surgery and 500 received primary endocrine therapy (125 were excluded from analysis due to inadequate data or non-standard therapy). Median follow-up was 52 months. The primary endocrine therapy group was older and less fit. Baseline QoL differed between the groups; the mean(s.d.) QLQ-C30 global health status score was 66.2(21.1) in patients who received primary endocrine therapy versus 77.1(17.8) among those who had surgery plus endocrine therapy. In the unmatched analysis, changes in QoL between 6 weeks and baseline were noted in several domains, but by 24 months most scores had returned to baseline levels. In the matched analysis, major surgery (mastectomy or axillary clearance) had a more pronounced adverse impact than primary endocrine therapy in several domains. CONCLUSION: Adverse effects on QoL are seen in the first few months after surgery, but by 24 months these have largely resolved. Women considering surgery should be informed of these effects.


Assuntos
Antineoplásicos Hormonais/uso terapêutico , Neoplasias da Mama/terapia , Qualidade de Vida , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/metabolismo , Neoplasias da Mama/psicologia , Feminino , Humanos , Estudos Longitudinais , Mastectomia , Estudos Prospectivos , Receptores de Estrogênio/metabolismo
6.
Br J Surg ; 108(5): 499-510, 2021 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-33760077

RESUMO

BACKGROUND: Rates of surgery and adjuvant therapy for breast cancer vary widely between breast units. This may contribute to differences in survival. This cluster RCT evaluated the impact of decision support interventions (DESIs) for older women with breast cancer, to ascertain whether DESIs influenced quality of life, survival, decision quality, and treatment choice. METHODS: A multicentre cluster RCT compared the use of two DESIs against usual care in treatment decision-making in older women (aged at least ≥70 years) with breast cancer. Each DESI comprised an online algorithm, booklet, and brief decision aid to inform choices between surgery plus adjuvant endocrine therapy versus primary endocrine therapy, and adjuvant chemotherapy versus no chemotherapy. The primary outcome was quality of life. Secondary outcomes included decision quality measures, survival, and treatment choice. RESULTS: A total of 46 breast units were randomized (21 intervention, 25 usual care), recruiting 1339 women (670 intervention, 669 usual care). There was no significant difference in global quality of life at 6 months after the baseline assessment on intention-to-treat analysis (difference -0.20, 95 per cent confidence interval (C.I.) -2.69 to 2.29; P = 0.900). In women offered a choice of primary endocrine therapy versus surgery plus endocrine therapy, knowledge about treatments was greater in the intervention arm (94 versus 74 per cent; P = 0.003). Treatment choice was altered, with a primary endocrine therapy rate among women with oestrogen receptor-positive disease of 21.0 per cent in the intervention versus 15.4 per cent in usual-care sites (difference 5.5 (95 per cent C.I. 1.1 to 10.0) per cent; P = 0.029). The chemotherapy rate was 10.3 per cent at intervention versus 14.8 per cent at usual-care sites (difference -4.5 (C.I. -8.0 to 0) per cent; P = 0.013). Survival was similar in both arms. CONCLUSION: The use of DESIs in older women increases knowledge of breast cancer treatment options, facilitates shared decision-making, and alters treatment selection. Trial registration numbers: EudraCT 2015-004220-61 (https://eudract.ema.europa.eu/), ISRCTN46099296 (http://www.controlled-trials.com).


Assuntos
Neoplasias da Mama/terapia , Tomada de Decisões , Técnicas de Apoio para a Decisão , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos Hormonais/uso terapêutico , Neoplasias da Mama/mortalidade , Quimioterapia Adjuvante , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Qualidade de Vida
7.
Water Resour Res ; 56(11)2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-33627891

RESUMO

In this synthesis, we assess present research and anticipate future development needs in modeling water quality in watersheds. We first discuss areas of potential improvement in the representation of freshwater systems pertaining to water quality, including representation of environmental interfaces, in-stream water quality and process interactions, soil health and land management, and (peri-)urban areas. In addition, we provide insights into the contemporary challenges in the practices of watershed water quality modeling, including quality control of monitoring data, model parameterization and calibration, uncertainty management, scale mismatches, and provisioning of modeling tools. Finally, we make three recommendations to provide a path forward for improving watershed water quality modeling science, infrastructure, and practices. These include building stronger collaborations between experimentalists and modelers, bridging gaps between modelers and stakeholders, and cultivating and applying procedural knowledge to better govern and support water quality modeling processes within organizations.

8.
New Phytol ; 223(2): 661-674, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30951191

RESUMO

Chronosequences at the forefront of retreating glaciers provide information about colonization rates of bare surfaces. In the northern hemisphere, forest development can take centuries, with rates often limited by low nutrient availability. By contrast, in front of the retreating Pia Glacier (Tierra del Fuego, Chile), a Nothofagus forest is in place after only 34 yr of development, while total soil nitrogen (N) increased from near zero to 1.5%, suggesting a strong input of this nutrient. We measured N-fixation rates, carbon fluxes, leaf N and phosphorus contents and leaf δ15 N in the dominant plants, including the herb Gunnera magellanica, which is endosymbiotically associated with a cyanobacterium, in order to investigate the role of N-fixing and mycorrhizal symbionts in N-budgets during successional transition. G. magellanica presented some of the highest nitrogenase activities yet reported (potential maximal contribution of 300 kg N ha-1  yr-1 ). Foliar δ15 N results support the framework of a highly efficient N-uptake and transfer system based on mycorrhizas, with c. 80% of N taken up by the mycorrhizas potentially transferred to the host plant. Our results suggest the symbiosis of G. magellanica with cyanobacteria, and trees and shrubs with mycorrhizas, to be the key processes driving this rapid succession.


Assuntos
Micorrizas/metabolismo , Nitrogênio/metabolismo , Traqueófitas/metabolismo , Traqueófitas/microbiologia , Regiões Antárticas , Ciclo do Carbono , Chile , Marcação por Isótopo , Fixação de Nitrogênio , Fósforo/metabolismo , Fotossíntese , Folhas de Planta/metabolismo , Solo
9.
Stat Med ; 35(1): 115-29, 2016 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-26202853

RESUMO

Incarceration provides an opportunity to test for HIV, provide treatment such as highly active anti-retroviral therapy, as well as link infected persons to comprehensive HIV care upon their release. A key factor in assessing the success of a program that links released individuals to care is the time from release to receiving care in the community (linkage time). To estimate the linkage time, records from correction systems are linked to Ryan White Clinic data using encrypted Unique Client Identifier (eUCI). Most of the records that were linked using eUCI belong to the same individual; however, in some cases, it may link records incorrectly, or not identify records that should have been linked. We propose a Bayesian procedure that relies on the relationships between variables that appear in either of the data sources, as well as variables that exists in both to identify correctly linked records among all linked records. The procedure generates K datasets in which each pair of linked records is identified as a true link or a false link. The K datasets are analyzed independently, and the results are combined using Rubin's multiple imputation rules. A small validation dataset is used to examine different statistical models and to inform the prior distributions of the parameters. In comparison with previously proposed methods, the proposed method utilizes all of the available data and is both flexible and computationally efficient. In addition, this approach can be applied in other file linking applications.


Assuntos
Infecções por HIV/diagnóstico , Registro Médico Coordenado/métodos , Sistemas de Identificação de Pacientes/métodos , Prisioneiros , Terapia Antirretroviral de Alta Atividade , Teorema de Bayes , Bioestatística/métodos , Serviços de Saúde Comunitária/métodos , Serviços de Saúde Comunitária/estatística & dados numéricos , Simulação por Computador , Confidencialidade , Infecções por HIV/tratamento farmacológico , Humanos , Modelos Estatísticos , Sistemas de Identificação de Pacientes/estatística & dados numéricos , Tempo para o Tratamento/estatística & dados numéricos
10.
J Strength Cond Res ; 30(3): 800-6, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26907844

RESUMO

This study compared acute postexercise oxygen consumption in 11 trained women (age, 46.5 ± 1.6 years; body mass index [BMI], 28.4 ± 1.7 kg·m(-2) and 11 untrained women (age, 46.5 ± 1.5 years; BMI, 27.5 ± 1.5 kg·m(-2)) after resistance exercise (RE). Resistance exercise consisted of 3 sets of 8 exercises (8-12 repetitions at 50-80% 1 repetition maximum). Oxygen consumption (VO2 ml·min(-1)) was measured before and after (0, 20, 40, 60, 90, and 120 minutes) RE. Immediately after cessation of RE (time 0), oxygen consumption increased in both trained and untrained women and remained significantly above baseline through 60 minutes after exercise (p < 0.01). Total oxygen consumption during recovery was 31.3 L in trained women and 27.4 L in untrained women (p = 0.07). In trained women, total oxygen consumption was strongly related to absolute (kg) lean mass (r = 0.88; p < 0.001), relative (kilogram per square meter) lean mass (r = 0.91; p < 0.001), and duration of exercise (r = 0.68; p ≤ 0.05), but in untrained women, only training volume-load was related to total oxygen consumption (r = 0.67; p ≤ 0.05). In trained women, 86% of the variance in oxygen consumption was explained by lean mass and exercise duration, whereas volume-load explained 45% in untrained women. Our findings suggest that, in women, resistance training increases metabolic activity of lean tissue. Postexercise energy costs of RE are determined by the duration of stimulation provided by RE rather than absolute work (volume-load) performed. This phenomenon may be related to type II muscle fibers and increased protein synthesis.


Assuntos
Metabolismo Energético , Consumo de Oxigênio , Condicionamento Físico Humano/fisiologia , Treinamento Resistido , Adulto , Composição Corporal , Feminino , Humanos , Pessoa de Meia-Idade , Músculo Esquelético/fisiologia , Fatores de Tempo
11.
Br J Cancer ; 112 Suppl 1: S41-9, 2015 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-25734388

RESUMO

BACKGROUND: General practitioners (GPs) have a key role in cancer detection as the usual first point of contact for patients with potential cancer symptoms. Nevertheless, there is limited work that investigates their perceptions of their role in the early detection of cancer. To address this gap, we aimed to gain an in-depth understanding of cancer diagnosis from the perspective of GPs. METHODS: Individual face-to-face semi-structured interviews were conducted with 55 GPs from the North and North East of England and Greater London. All interviews were recorded and professionally transcribed verbatim. Repeated reading and co-coding engendered systematic thematic analysis across the interview material. RESULTS: Three main themes emerged from the analysis of our data. First, we identified the burden of early cancer detection in general practice, both related to the anxiety and symptoms patients bring to GPs and the need for GPs to recognise patterns of cancer symptoms and refer appropriately; second, this burden is intensified by a perceived fragmentation of services within the National Health Service (NHS); and third, it is made more complex by the interface between general practice and public health. CONCLUSIONS: GPs occupy a challenging but pivotal role in cancer detection. It is crucial that this role be supported by policy and research.


Assuntos
Atitude do Pessoal de Saúde , Medicina Geral , Neoplasias/diagnóstico , Atenção Primária à Saúde , Continuidade da Assistência ao Paciente , Detecção Precoce de Câncer , Inglaterra , Humanos , Educação de Pacientes como Assunto , Relações Médico-Paciente , Padrões de Prática Médica , Pesquisa Qualitativa , Encaminhamento e Consulta
12.
J Intern Med ; 278(3): 323-32, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25880119

RESUMO

OBJECTIVE: TRIM21 (also known as Ro52) is an autoantigen in rheumatic disease and is predominantly expressed in leucocytes. Overexpression is associated with decreased proliferation, and the TRIM21 gene maps to a tumour suppressor locus. We therefore investigated the expression of TRIM21 in patients with diffuse large B-cell lymphoma (DLBCL) and its potential usefulness as a prognostic biomarker. MATERIALS AND METHODS: TRIM21 expression levels were assessed by immunohistochemistry in lymphoma biopsies from three cohorts of patients with DLBCL: 42 patients with rheumatic disease treated with a cyclophosphamide, vincristine, doxorubicin and prednisone (CHOP)-like regimen, 76 CHOP-treated and 196 rituximab-CHOP-treated nonrheumatic patients. Expression was correlated with clinical and biomedical parameters. TRIM21 expression was assessed in relation to lymphocyte proliferation by quantitative PCR and correlated with (3) H-thymidine incorporation and propidium iodine staining. RESULTS: TRIM21 expression levels differed in the lymphomas compared to normal lymphoid tissue, with reduced expression correlating with shorter overall survival in all three cohorts. In the two larger cohorts, progression-free survival was assessed and was also found to correlate with TRIM21 expression. The association was independent of commonly used clinical prognostic scores, lymphoma subtype and several previously reported prognostic biomarkers. In agreement with this clinical observation, we noted an inverse correlation between TRIM21 expression and proliferation of leucocytes in vitro. CONCLUSIONS: We show that loss of TRIM21 expression is associated with more aggressive lymphoma and increased proliferation, whereas maintenance of TRIM21 expression is associated with better prognosis in patients with DLBCL. Based on our findings, we suggest that TRIM21 should be considered as a novel biomarker for lymphoma characterization and for predicting patient survival.


Assuntos
Biomarcadores/análise , Linfoma Difuso de Grandes Células B/mortalidade , Doenças Reumáticas/complicações , Ribonucleoproteínas/análise , Idoso , Anticorpos Monoclonais Murinos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Células Cultivadas , Ciclofosfamida/uso terapêutico , Doxorrubicina/uso terapêutico , Feminino , Humanos , Imuno-Histoquímica , Técnicas In Vitro , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Masculino , Prednisolona/uso terapêutico , Prednisona/uso terapêutico , Prognóstico , Reação em Cadeia da Polimerase em Tempo Real , Rituximab , Vincristina/uso terapêutico
13.
Oecologia ; 173(1): 59-72, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23440504

RESUMO

Antarctica, with its almost pristine conditions and relatively simple vegetation, offers excellent opportunities to investigate the influence of environmental factors on species performance, such information being crucial if the effects of possible climate change are to be understood. Antarctic vegetation is mainly cryptogamic. Cryptogams are poikilohydric and are only metabolically and photosynthetically active when hydrated. Activity patterns of the main life forms present, bryophytes (10 species, ecto- and endohydric), lichens (5 species) and phanerogams (2 species), were monitored for 21 days using chlorophyll a fluorescence as an indicator of metabolic activity and, therefore, of water regime at a mesic (hydration by meltwater) and a xeric (hydration by precipitation) site on Léonie Island/West Antarctic Peninsula (67°36'S). Length of activity depended mainly on site and form of hydration. Plants at the mesic site that were hydrated by meltwater were active for long periods, up to 100 % of the measurement period, whilst activity was much shorter at the xeric site where hydration was entirely by precipitation. There were also differences due to life form, with phanerogams and mesic bryophytes being most active and lichens generally much less so. The length of the active period for lichens was longer than in continental Antarctica but shorter than in the more northern Antarctic Peninsula. Light intensity when hydrated was positively related to the length of the active period. High activity species were strongly coupled to the incident light whilst low activity species were active under lower light levels and essentially uncoupled from incident light. Temperatures were little different between sites and also almost identical to temperatures, when active, for lichens in continental and peninsular Antarctica. Gradients in vegetation cover and growth rates across Antarctica are, therefore, not likely to be due to differences in temperature but more likely to the length of the hydrated (active) period. The strong effect on activity of the mode of hydration and the life form, plus the uncoupling from incident light for less active species, all make modelling of vegetation change with climate a more difficult exercise.


Assuntos
Briófitas/metabolismo , Mudança Climática , Ecossistema , Líquens/metabolismo , Água/metabolismo , Regiões Antárticas , Briófitas/fisiologia , Clorofila/metabolismo , Clorofila A , Líquens/fisiologia , Microclima , Temperatura , Fatores de Tempo
14.
J Dairy Sci ; 96(5): 3098-107, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23489775

RESUMO

Residual feed intake (RFI) is a measure of an individual's efficiency in utilizing feed for maintenance and production during growth or lactation, and is defined as the difference between the actual and predicted feed intake of that individual. The objective of this study was to relate RFI to feeding behavior and to identify behavioral differences between animals with divergent RFI. The intakes and body weight (BW) of 1,049 growing dairy heifers (aged 5-9 mo; 195 ± 25.8 kg of BW) in 5 cohorts were measured for 42 to 49 d to ascertain individual RFI. Animals were housed in an outdoor feeding facility comprising 28 pens, each with 8 animals and 1 feeder per pen, and were fed a dried, cubed alfalfa diet. This forage diet was chosen because most dairy cows in New Zealand are grazed on ryegrass-dominant pastures, without grain or concentrates. An electronic feed monitoring system measured the intake and feeding behavior of individuals. Feeding behavior was summarized as daily intake, daily feeding duration, meal frequency, feeding rate, meal size, meal duration, and temporal feeding patterns. The RFI was moderately to strongly correlated with intake in all cohorts (r=0.54-0.74), indicating that efficient animals ate less than inefficient animals, but relationships with feeding behavior traits (meal frequency, feeding duration, and feeding rate) were weak (r=0.14-0.26), indicating that feeding behavior cannot reliably predict RFI in growing dairy heifers. Comparison of the extremes of RFI (10% most and 10% least efficient) demonstrated similar BW and average daily gain for both groups, but efficient animals ate less; had fewer, longer meals; shorter daily feeding duration; and ate more slowly than the least-efficient animals. These groups also differed in their feeding patterns over 24h, with the most efficient animals eating less and having fewer meals during daylight (0600 to 2100 h), especially during the afternoon (1200 to 1800 h), but ate for a longer time during the night (0000-0600 h) than the least-efficient animals. In summary, correlations between RFI and feeding behavior were weak. Small differences in feeding behavior were observed between the most- and least-efficient animals but adverse behavioral effects associated with such selection in growing dairy heifers are unlikely.


Assuntos
Ingestão de Alimentos/fisiologia , Comportamento Alimentar/fisiologia , Aumento de Peso/fisiologia , Animais , Peso Corporal , Bovinos/crescimento & desenvolvimento , Bovinos/fisiologia , Dieta/veterinária , Feminino
15.
Nat Genet ; 28(1): 87-91, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11326283

RESUMO

The genetics of asthma and atopy have been difficult to determine because these diseases are genetically heterogeneous and modified by environment. The pedigrees in our study (n=86) originate in eastern central Finland (Kainuu province). According to census records, this region had only 200 households (2,000 inhabitants) in the mid sixteenth to mid seventeenth centuries. The current population of 100,000 represents the expansion of these founders within the past 400 years. Because this population is relatively homogeneous, we hypothesized that the molecular genetic mechanisms underlying asthma might also have reduced heterogeneity and therefore be easier to dissect than in mixed populations. A recent twin family study supported a strong genetic component for asthma in Finland. We carried out a genome-wide scan for susceptibility loci in asthma in the Kainuu subpopulation. We identified two regions of suggestive linkage and studied them further with higher-density mapping. We obtained evidence for linkage in a 20-cM region of chromosome 7p14-p15 for three phenotypes: asthma, a high level of immunoglobulin E (IgE; atopy) and the combination of the phenotypes. The strongest linkage was seen for high serum IgE (non-parametric linkage (NPL) score 3.9, P=0.0001), exceeding the threshold for genome-wide significance based on simulations. We also observed linkage between this locus and asthma or atopy in two independent data sets.


Assuntos
Asma/genética , Cromossomos Humanos Par 7/genética , Efeito Fundador , Hipersensibilidade Imediata/genética , Asma/epidemiologia , Mapeamento Cromossômico , Feminino , Finlândia/epidemiologia , Ligação Genética , Marcadores Genéticos , Predisposição Genética para Doença , Genoma Humano , Humanos , Hipersensibilidade Imediata/epidemiologia , Imunoglobulina E , Masculino , Linhagem
16.
Nat Genet ; 29(2): 223-8, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11586304

RESUMO

Linkage disequilibrium (LD) mapping provides a powerful method for fine-structure localization of rare disease genes, but has not yet been widely applied to common disease. We sought to design a systematic approach for LD mapping and apply it to the localization of a gene (IBD5) conferring susceptibility to Crohn disease. The key issues are: (i) to detect a significant LD signal (ii) to rigorously bound the critical region and (iii) to identify the causal genetic variant within this region. We previously mapped the IBD5 locus to a large region spanning 18 cM of chromosome 5q31 (P<10(-4)). Using dense genetic maps of microsatellite markers and single-nucleotide polymorphisms (SNPs) across the entire region, we found strong evidence of LD. We bound the region to a common haplotype spanning 250 kb that shows strong association with the disease (P< 2 x 10(-7)) and contains the cytokine gene cluster. This finding provides overwhelming evidence that a specific common haplotype of the cytokine region in 5q31 confers susceptibility to Crohn disease. However, genetic evidence alone is not sufficient to identify the causal mutation within this region, as strong LD across the region results in multiple SNPs having equivalent genetic evidence-each consistent with the expected properties of the IBD5 locus. These results have important implications for Crohn disease in particular and LD mapping in general.


Assuntos
Cromossomos Humanos Par 5 , Doença de Crohn/genética , Citocinas/genética , Predisposição Genética para Doença , Variação Genética , Família Multigênica , Mapeamento Cromossômico , Humanos , Desequilíbrio de Ligação , Polimorfismo de Nucleotídeo Único
17.
J Strength Cond Res ; 27(7): 1885-90, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23037618

RESUMO

In untrained adults, multiple trials of maximal strength testing are necessary to obtain reliable measures. Training status may positively influence test-retest reliability and increase testing efficiency. The purpose of this study was to evaluate the effect of training status on differences between trials of 1 repetition maximum (1RM) measurement in women. Before (untrained women [UTW]) and after (trained women [TRW]) an 8-week resistance training program, 10 women (45.6 ± 1.4 years; body mass index 28.7 ± 1.6 kg·m) completed 3 trials of 1RM chest and leg press with at least 24 hours rest between trials. In UTW, differences between chest press trials were nonsignificant (trials 1-2: 2.36 ± 1.39 kg, p = 0.37; trials 2-3: 0.82 ± 0.77 kg, p = 0.95; trials 1-3: 3.18 ± 0.16 kg, p = 0.07), although a significant difference between leg press trials 1-3 was observed (trials 1-2: 6.55 ± 3.31 kg, p = 0.25; trials 2-3: 2.52 ± 1.1 kg, p = 0.15; trials 1-3: 9.07 ± 2.83 kg, p = 0.04). In TRW, differences between all 1RM trials were nonsignificant for both the chest press (trials 1-2: -0.65 ± 2.11 kg, p = 1.0; trials 2-3: 1.62 ± 0.69 kg, p = 0.15; trials 1-3: 0.96 ± 2.07 kg, p = 1.0) and leg press (trials 1-2: -1.51 ± 2.13 kg, p = 1.0; trials 2-3: 3.53 ± 3.0 kg, p = 0.82; trials 1-3: 2.01 ± 3.87 kg, p = 1.0). Our results suggest that training status has a positive influence on the efficiency of maximal strength measurement. For trained middle-aged women, a single trial of 1RM chest or leg press may be sufficient to obtain an accurate and reliable measure of maximal strength.


Assuntos
Teste de Esforço , Extremidade Inferior/fisiologia , Força Muscular/fisiologia , Treinamento Resistido/métodos , Extremidade Superior/fisiologia , Adulto , Antropometria , Feminino , Humanos , Pessoa de Meia-Idade , Aptidão Física/fisiologia , Reprodutibilidade dos Testes
18.
Diabetologia ; 55(2): 331-9, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22038522

RESUMO

AIMS/HYPOTHESIS: Common genetic variants have been associated with type 2 diabetes. We hypothesised that a subset of these variants may have different effects on the transition from normal fasting glucose (NFG) to impaired fasting glucose (IFG) than on that from IFG to diabetes. METHODS: We identified 16 type 2 diabetes risk variants from the Illumina Broad Candidate-gene Association Resource (CARe) array genotyped in 26,576 CARe participants. Participants were categorised at baseline as NFG, IFG or type 2 diabetic (n = 16,465, 8,017 or 2,291, respectively). Using Cox proportional hazards and likelihood ratio tests (LRTs), we compared rates of progression by genotype for 4,909 (NFG to IFG) and 1,518 (IFG to type 2 diabetes) individuals, respectively. We then performed multinomial regression analyses at baseline, comparing the risk of assignment to the NFG, IFG or diabetes groups by genotype. RESULTS: The rate of progression from NFG to IFG was significantly greater in participants carrying the risk allele at MTNR1B (p = 1 × 10(-4)), nominally greater at GCK and SLC30A8 (p < 0.05) and nominally smaller at IGF2BP2 (p = 0.01) than the rate of progression from IFG to diabetes by the LRT. Results of the baseline, multinomial regression model were consistent with these findings. CONCLUSIONS/INTERPRETATION: Common genetic risk variants at GCK, SLC30A8, IGF2BP2 and MTNR1B influence to different extents the development of IFG and the transition from IFG to type 2 diabetes. Our findings may have implications for understanding the genetic contribution of these variants to the development of IFG and type 2 diabetes.


Assuntos
Glicemia/metabolismo , Diabetes Mellitus Tipo 2/genética , Variação Genética , Adulto , Idoso , Glicemia/análise , Estudos de Coortes , Progressão da Doença , Jejum , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Genéticos , Polimorfismo de Nucleotídeo Único , Modelos de Riscos Proporcionais , Análise de Regressão , Risco
19.
Ann Bot ; 110(3): 555-63, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22648879

RESUMO

BACKGROUND AND AIMS: Cyanolichens are usually stated to be bipartite (mycobiont plus cyanobacterial photobiont). Analyses revealed green algal carbohydrates in supposedly cyanobacterial lichens (in the genera Pseudocyphellaria, Sticta and Peltigera). Investigations were carried out to determine if both cyanobacteria and green algae were present in these lichens and, if so, what were their roles. METHODS: The types of photobiont present were determined by light and fluorescence microscopy. Small carbohydrates were analysed to detect the presence of green algal metabolites. Thalli were treated with selected strengths of Zn(2+) solutions that stop cyanobacterial but not green algal photosynthesis. CO(2) exchange was measured before and after treatment to determine the contribution of each photobiont to total thallus photosynthesis. Heterocyst frequencies were determined to clarify whether the cyanobacteria were modified for increased nitrogen fixation (high heterocyst frequencies) or were normal, vegetative cells. KEY RESULTS: Several cyanobacterial lichens had green algae present in the photosynthetic layer of the thallus. The presence of the green algal transfer carbohydrate (ribitol) and the incomplete inhibition of thallus photosynthesis upon treatment with Zn(2+) solutions showed that both photobionts contributed to the photosynthesis of the lichen thallus. Low heterocyst frequencies showed that, despite the presence of adjacent green algae, the cyanobacteria were not altered to increase nitrogen fixation. CONCLUSIONS: These cyanobacterial lichens are a tripartite lichen symbiont combination in which the mycobiont has two primarily photosynthetic photobionts, 'co-primary photobionts', a cyanobacterium (dominant) and a green alga. This demonstrates high flexibility in photobiont choice by the mycobiont in the Peltigerales. Overall thallus appearance does not change whether one or two photobionts are present in the cyanobacterial thallus. This suggests that, if there is a photobiont effect on thallus structure, it is not specific to one or the other photobiont.


Assuntos
Ascomicetos/metabolismo , Dióxido de Carbono/metabolismo , Clorófitas/metabolismo , Cianobactérias/metabolismo , Líquens/metabolismo , Líquens/microbiologia , Fotossíntese/fisiologia , Fixação de Nitrogênio/fisiologia , Simbiose
20.
Am J Bot ; 99(4): e131-3, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22447983

RESUMO

PREMISE OF THE STUDY: Microsatellite markers were characterized for an Antarctic endemic, Buellia frigida, to investigate population structure and origin of Antarctic lichens. METHODS AND RESULTS: Five primer sets were characterized. All loci were polymorphic with eight to 16 alleles per locus in a sample of 59 lichens. CONCLUSIONS: The microsatellite markers potentially provide insight into population structure and gene flow of B. frigida.


Assuntos
DNA de Plantas/genética , DNA de Plantas/isolamento & purificação , Líquens/genética , Repetições de Microssatélites/genética , Regiões Antárticas , Primers do DNA , Loci Gênicos/genética , Dados de Sequência Molecular
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