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1.
Ecol Appl ; 29(8): e01997, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31483902

RESUMO

In an era characterized by recurrent large wildfires in many parts of the globe, there is a critical need to understand how animal species respond to fires, the rates at which populations can recover, and the functional changes fires may cause. Using quantified changes in habitat parameters over a ~400-yr post-fire chronosequence in an obligate-seeding Australian eucalypt woodland, we build and test predictions of how birds, as individual species and aggregated into functional groups according to their use of specific habitat resources, respond to time since fire. Individual bird species exhibited four generalized response types to time since fire: incline, decline, delayed, and bell. All significant relationships between bird functional group richness or abundance and time since fire were consistent with predictions based on known time-since-fire-associated changes in habitat features putatively important for these bird groups. Consequently, we argue that the bird community is responding to post-fire successional changes in habitat as per the habitat accommodation model, rather than to time since fire per se, and that our functional framework will be of value in predicting bird responses to future disturbances in this and other obligate-seeder forest and woodland ecosystems. Most bird species and functional groups that were affected by time since fire were associated with long-unburned woodlands. In the context of recent large, stand-replacement wildfires that have affected a substantial proportion of obligate-seeder eucalypt woodlands, and the multi-century timescales over which post-fire succession occurs, it would appear preferable from a bird conservation perspective if fires initiating loss of currently long-unburned woodlands were minimized. Once long-unburned woodlands are transformed by fire into recently burned woodlands, there is limited scope for alternative management interventions to accelerate the rate of habitat development after fire, or supplement the resources formerly provided to birds by long-unburned woodlands, with the limited exception of augmenting hollow availability for key hollow-nesting species.


Assuntos
Ecossistema , Incêndios , Animais , Austrália , Aves , Conservação dos Recursos Naturais , Florestas , Dinâmica Populacional
2.
J Comput Aided Mol Des ; 30(2): 103-26, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26942422

RESUMO

The calculation of error bars for quantities of interest in computational chemistry comes in two forms: (1) Determining the confidence of a prediction, for instance of the property of a molecule; (2) Assessing uncertainty in measuring the difference between properties, for instance between performance metrics of two or more computational approaches. While a former paper in this series concentrated on the first of these, this second paper focuses on comparison, i.e. how do we calculate differences in methods in an accurate and statistically valid manner. Described within are classical statistical approaches for comparing widely used metrics such as enrichment, area under the curve and Pearson's product-moment coefficient, as well as generic measures. These are considered of over single and multiple sets of data and for two or more methods that evince either independent or correlated behavior. General issues concerning significance testing and confidence limits from a Bayesian perspective are discussed, along with size-of-effect aspects of evaluation.


Assuntos
Teorema de Bayes , Biologia Computacional/estatística & dados numéricos , Modelos Moleculares , Algoritmos , Modelos Teóricos
3.
Br J Anaesth ; 116(1): 18-26, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26675948

RESUMO

Insulin pump therapy is increasingly common in patients with type 1 diabetes. Many of these patients will require surgery at some point in their lifetime. Few doctors will have experience of managing these patients, and little evidence exists to assist in the development of guidelines for patients with insulin pump therapy, undergoing surgery.It is clear that during emergency surgery insulin pump therapy is not appropriate and should be discontinued, but patients undergoing some elective surgery can and should continue insulin pump therapy, without any adverse effect on their blood sugar control, or on the outcome of their surgery. Individual hospitals need to formalize guidance on the management of patients receiving continuous subcutaneous insulin therapy, to allow patients the choice to continue their therapy during surgery. This expert opinion presents anaesthetists with a suggested clinical framework to help facilitate continued insulin pump therapy, during elective surgery and into the postoperative period.


Assuntos
Anestesia/métodos , Diabetes Mellitus Tipo 1/tratamento farmacológico , Sistemas de Infusão de Insulina , Insulina/uso terapêutico , Humanos , Hipoglicemiantes/uso terapêutico , Período Perioperatório
4.
J Comput Aided Mol Des ; 28(9): 887-918, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24899109

RESUMO

Computational chemistry is a largely empirical field that makes predictions with substantial uncertainty. And yet the use of standard statistical methods to quantify this uncertainty is often absent from published reports. This article covers the basics of confidence interval estimation for molecular modeling using classical statistics. Alternate approaches such as non-parametric statistics and bootstrapping are discussed.


Assuntos
Desenho Assistido por Computador , Modelos Moleculares , Algoritmos , Área Sob a Curva , Humanos , Modelos Lineares , Distribuição Normal , Probabilidade
5.
Phys Rev Lett ; 111(23): 237401, 2013 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-24476300

RESUMO

A theoretical development of prior analyses, together with our solenoid scan measurements on eight planar metal photocathodes (Ag, Be, Cr, Cu, Mo, Sn, Ta, and W) and previous data on Mg [X. J. Wang, M. Babzien, R. Malone, and Z. Wu, in Proceedings of LINAC2002, Gyeongju, Korea, 2002 (Pohang Accelerator Laboratory, Pohang, Korea, 2002), pp. 142-144.] indicate that the transverse momentum (and hence intrinsic emittance) of an electron beam is fundamentally dependent on the electron effective mass in the metal.

6.
Scand J Med Sci Sports ; 21(5): 721-9, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20459476

RESUMO

The primary aim of this study was to investigate the relationship between confidence and subjective performance in addition to exploring whether coping mediated this relationship. A sample of 414 athletes completed a measure of confidence before performance. Athletes also completed a measure of coping and subjective performance after competing. Correlational findings revealed that confidence was positively and significantly associated with subjective performance. Furthermore, mediational analysis found that coping partly mediated this relationship. In particular, task-oriented coping (i.e., mental imagery) and disengagement-oriented coping (i.e., resignation) had positive and negative mediational effects, respectively. Additionally, athletes who employed mental imagery generally coped more effectively than those using resignation. These findings imply mental imagery has the potential not only to improve confidence, but also subsequent performance, while resignation coping may have the opposite effect. Overall, these results lend some credence to Vealey's integrated sports confidence model.


Assuntos
Adaptação Psicológica , Desempenho Atlético/psicologia , Atitude , Comportamento Competitivo , Esportes/psicologia , Adolescente , Adulto , Feminino , Humanos , Imaginação , Masculino , Testes Psicológicos , Adulto Jovem
7.
Br J Cancer ; 103(3): 340-6, 2010 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-20606684

RESUMO

BACKGROUND: Colorectal cancer is (CRC) one of the commonest cancers and its therapy is still based on few drugs. Currently, no biological criteria are used to choose the most effective of the established drugs for treatment. METHODS: A panel of 77 CRC cell lines was tested for sensitivity to 5-fluorouracil (5FU) using the SRB assay. The responses were grouped into three categories and correlated with genetic changes in the cell lines. RESULTS: The strongest and most clearcut correlation was between 5-fluorouracil response and replication error status (mismatch repair deficiency). All the other significant correlations (loss of heterozygosity for DCC and mutations in TGFbIIR) are secondary to the association with replication error status. INTERPRETATION AND CONCLUSION: Our findings validate previous analyses based mainly on clinical data, and indicate that replication error status could be a useful guide to 5-fluorouracil-based CRC therapy. Essentially, all previously described correlations with 5FU response are secondary to the association with replication error status.


Assuntos
Linhagem Celular Tumoral/efeitos dos fármacos , Neoplasias Colorretais/tratamento farmacológico , Reparo de Erro de Pareamento de DNA/efeitos dos fármacos , Fluoruracila/toxicidade , Antimetabólitos Antineoplásicos/toxicidade , Materiais Biocompatíveis , Colágeno , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Replicação do DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Combinação de Medicamentos , Humanos , Laminina , Perda de Heterozigosidade/efeitos dos fármacos , Mutação , Proteoglicanas
8.
Scand J Med Sci Sports ; 20(2): 346-55, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19486482

RESUMO

The aims of this study were to (a) explore the emotions generated during or as a consequence of stress appraisals, after coping, and after the event outcome, (b) explore whether multiple emotions were generated from the initial stress appraisal through to event outcome, and (c) to explore whether outcomes that were perceived as favorable resulted in positive emotions and outcomes that were perceived as unfavorable or neither favorable nor unfavorable resulted in negatively toned emotions. Participants were 10 male English international adolescent golfers (mean+/-SD; age 16.7+/-1.6 years), who were interviewed regarding their experiences of stress appraisals, emotions, and coping during competitive golf. Results revealed that emotions were generated within or as a consequence of stress appraisals, after coping, and after the event outcome. Additionally, multiple emotions were generated from the stressful appraisal to the event outcome. Positively toned emotions were cited more frequently than negatively toned emotions after favorable events, whereas negatively toned emotions were reported more frequently than positively toned emotions after unfavorable events. Coping appears important in generating positively toned emotions.


Assuntos
Adaptação Psicológica , Emoções , Golfe/psicologia , Estresse Psicológico/psicologia , Adolescente , Feminino , Humanos , Controle Interno-Externo , Masculino , Modelos Psicológicos , Inventário de Personalidade
9.
Science ; 268(5214): 1144-9, 1995 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-7761829

RESUMO

A major revival in the use of classical electrostatics as an approach to the study of charged and polar molecules in aqueous solution has been made possible through the development of fast numerical and computational methods to solve the Poisson-Boltzmann equation for solute molecules that have complex shapes and charge distributions. Graphical visualization of the calculated electrostatic potentials generated by proteins and nucleic acids has revealed insights into the role of electrostatic interactions in a wide range of biological phenomena. Classical electrostatics has also proved to be successful quantitative tool yielding accurate descriptions of electrical potentials, diffusion limited processes, pH-dependent properties of proteins, ionic strength-dependent phenomena, and the solvation free energies of organic molecules.


Assuntos
Bioquímica/métodos , Físico-Química , Eletricidade , Eletroquímica , Fenômenos Químicos , Modelos Químicos , Modelos Teóricos , Estrutura Molecular , Ácidos Nucleicos/química , Proteínas/química , Termodinâmica
10.
Science ; 252(5002): 106-9, 1991 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-2011744

RESUMO

The magnitude of the hydrophobic effect, as measured from the surface area dependence of the solubilities of hydrocarbons in water, is generally thought to be about 25 calories per mole per square angstrom (cal mol-1 A-2). However, the surface tension at a hydrocarbon-water interface, which is a "macroscopic" measure of the hydrophobic effect, is approximately 72 cal mol-1 A-2. In an attempt to reconcile these values, alkane solubility data have been reevaluated to account for solute-solvent size differences, leading to a revised "microscopic" hydrophobic effect of 47 cal mol-1 A-2. This value, when used in a simple geometric model for the curvature dependence of the hydrophobic effect, predicts a macroscopic alkane-water surface tension that is close to the macroscopic value.


Assuntos
Hidrocarbonetos/química , Solubilidade , Termodinâmica , Água
12.
Scand J Med Sci Sports ; 19(1): 121-8, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18248539

RESUMO

The purpose of the present study was to examine (a) the sources of sport and non-sport stress and their associated symptoms on rest days, training days, and match days and (b) the temporal aspects of sources and symptoms of stress and affective states. Professional male rugby union players (n=16) completed the Daily Analysis of Life Demands in Athletes (DALDA) and the Activation Deactivation Adjective Check List (AD ACL) for 28 days. On match days players reported that few stressors were "worse than normal." Most stressors were "worse than normal" on training days followed by rest days and more stressors were "worse than normal" on the day after a match than on match days. Further, players reported an unpleasant, low activation state across the three analysis days, suggesting they were in an overtrained state. The findings of this study demonstrate that professional rugby players experience negative affect and a multitude of sport and non-sport stressors. Early detection of stressors and negative affective states could help prevent symptoms of overtraining and burnout and facilitate optimal training and sporting performance. Coaches and practitioners are encouraged to integrate the DALDA and AD ACL in their training and performance monitoring regimes.


Assuntos
Afeto , Futebol Americano/psicologia , Estresse Psicológico/epidemiologia , Adolescente , Humanos , Masculino , Aptidão Física/psicologia , Psicometria/instrumentação , Inquéritos e Questionários , Reino Unido , Adulto Jovem
13.
Scand J Med Sci Sports ; 19(1): 113-20, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18282223

RESUMO

The purpose of this study was to examine acute sport-related stressors, coping, and emotion among a sample of professional rugby union players during training and matches. Five professional rugby union players maintained diaries for 31 days. The diaries consisted of a stressor checklist and an open-ended stressor response section, an open-ended coping response section, a Likert-type evaluation of coping effectiveness, a best-of-fit emotional response section, and a Likert-type evaluation of emotional intensity. Six out of the 10 stressors reported had a higher mean frequency in training compared with matches. Blocking was the most frequently cited coping strategy on match days, whereas increased concentration was the most frequently cited coping strategy on training days. Coping effectiveness was significantly higher during training compared with matches. Additionally, higher levels of emotional intensity were significantly associated with lower levels of coping effectiveness. Significant individual differences were found for both coping effectiveness and emotional intensity.


Assuntos
Adaptação Psicológica , Emoções , Futebol Americano/psicologia , Aptidão Física/psicologia , Estresse Psicológico/etiologia , Adulto , Documentação , Humanos , Masculino , Adulto Jovem
14.
Science ; 358(6369): 1427-1430, 2017 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-29170281

RESUMO

Supported nanoparticles containing more than one metal have a variety of applications in sensing, catalysis, and biomedicine. Common synthesis techniques for this type of material often result in large, unalloyed nanoparticles that lack the interactions between the two metals that give the particles their desired characteristics. We demonstrate a relatively simple, effective, generalizable method to produce highly dispersed, well-alloyed bimetallic nanoparticles. Ten permutations of noble and base metals (platinum, palladium, copper, nickel, and cobalt) were synthesized with average particle sizes from 0.9 to 1.4 nanometers, with tight size distributions. High-resolution imaging and x-ray analysis confirmed the homogeneity of alloying in these ultrasmall nanoparticles.

15.
Diabetes ; 50(9): 2047-52, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11522670

RESUMO

Hepatocyte nuclear factor-1alpha (HNF-1alpha) mutations are the most common cause of maturity-onset diabetes of the young. HNF-1alpha homozygous knockout mice exhibit a renal Fanconi syndrome with glucosuria and generalized aminoaciduria in addition to diabetes. We investigated glucosuria and aminoaciduria in patients with HNF-1alpha mutations. Sixteen amino acids were measured in urine samples from patients with HNF-1alpha mutations, age-matched nondiabetic control subjects, and age-matched type 1 diabetic patients, type 2 diabetic patients, and patients with diabetes and chronic renal failure. The HNF-1alpha patients had glucosuria at lower glycemic control (as shown by HbA1c) than type 1 and type 2 diabetic patients, consistent with a lower renal glucose threshold. The HNF-1alpha patients had a generalized aminoaciduria with elevated levels of 14 of 16 amino acids and an increased mean Z score for all amino acids compared with control subjects (0.66 vs. 0.00; P < 0.0005). Generalized aminoaciduria was also present in type 1 diabetic (Z score, 0.80; P < 0.0001), type 2 diabetic (Z score, 0.71; P < 0.0002), and chronic renal failure (Z score, 0.65; P < 0.01) patients. Aminoaciduria was not associated with microalbuminuria or proteinuria but was associated with glucosuria (1.00 glucosuria vs. 0.19 no glucosuria; P = 0.002). In type 1 diabetic patients, urine samples taken on the same day showed significantly more aminoaciduria when glucosuria was present compared with when it was absent (P < 0.01). In conclusion, HNF-1alpha mutation carriers have a mutation-specific defect of proximal tubular glucose transport, resulting in increased glucosuria. In contrast, the generalized aminoaciduria seen in patients with HNF-1alpha mutations is a general feature of patients with diabetes and glucosuria. Glucose may depolarize and dissipate the electrical gradient of the sodium-dependent amino acid transporters in the proximal renal tubule, causing a reduction in amino acid resorption.


Assuntos
Aminoácidos/urina , Proteínas de Ligação a DNA , Diabetes Mellitus Tipo 1/urina , Diabetes Mellitus Tipo 2/urina , Glicosúria/etiologia , Mutação , Proteínas Nucleares , Fatores de Transcrição/genética , Adulto , Albuminúria/complicações , Ritmo Circadiano , Nefropatias Diabéticas/urina , Hemoglobinas Glicadas/análise , Glicosúria/complicações , Fator 1 Nuclear de Hepatócito , Fator 1-alfa Nuclear de Hepatócito , Fator 1-beta Nuclear de Hepatócito , Humanos , Falência Renal Crônica/urina , Pessoa de Meia-Idade , Concentração Osmolar , Proteinúria/complicações , Valores de Referência
16.
Artigo em Inglês | MEDLINE | ID: mdl-26211530

RESUMO

AIM: We conducted two studies that examined different models, which included mental toughness and psychological constructs that have been found to be related to this construct. METHODS: In Study 1, 531 athletes completed measures of mental toughness, resilience, and emotional intelligence. In Study 2, 522 athletes completed measures of mental toughness, sport motivation, and self-efficacy. RESULTS: There were positive paths between the constructs in the model, which were mediated by mental toughness in Study 1. Further, there was a positive path between mental toughness and self-efficacy, but negative paths with introjected regulation and amotivation in Study 2. CONCLUSION: This two study paper suggests that it might also be the presence of constructs such as resilience, emotional intelligence, motivation, and/or self-efficacy that enable mentally tough individuals to excel under stressful circumstances rather than just coping.

17.
J Sports Med Phys Fitness ; 55(7-8): 824-34, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26360967

RESUMO

AIM: We conducted two studies that examined different models, which included mental toughness and psychological constructs that are thought to be related to this construct. METHODS: In Study 1, 531 athletes completed measures of mental toughness, resilience, and emotional intelligence. In Study 2, 522 athletes completed measures of mental toughness, sport motivation, and self-efficacy. RESULTS: There were positive paths between the constructs in the model, which were mediated by mental toughness in Study 1. Further, there was a positive path between mental toughness and self-efficacy, but negative paths with introjected regulation and amotivation in Study 2. CONCLUSION: This two study paper suggests that it might also be the presence of constructs such as resilience, emotional intelligence, motivation, and/or self-efficacy that enable mentally tough individuals to excel under stressful circumstances rather than just coping.


Assuntos
Atletas/psicologia , Desempenho Atlético/psicologia , Adaptação Psicológica , Adolescente , Adulto , Inteligência Emocional , Feminino , Humanos , Masculino , Motivação , Resiliência Psicológica , Autoeficácia , Inquéritos e Questionários
18.
J Sports Med Phys Fitness ; 55(7-8): 835-44, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25665740

RESUMO

AIM: This study explored the mediating role of sport confidence upon (1) sources of sport confidence-performance relationship and (2) imagery-performance relationship. METHODS: Participants were 157 competitive athletes who completed state measures of confidence level/sources, imagery type and performance within one hour after competition. RESULTS: Among the current sample, confirmatory factor analysis revealed appropriate support for the nine-factor SSCQ and the five-factor SIQ. Mediational analysis revealed that sport confidence had a mediating influence upon the achievement source of confidence-performance relationship. In addition, both cognitive and motivational imagery types were found to be important sources of confidence, as sport confidence mediated imagery type- performance relationship. CONCLUSION: Findings indicated that athletes who construed confidence from their own achievements and report multiple images on a more frequent basis are likely to benefit from enhanced levels of state sport confidence and subsequent performance.


Assuntos
Atletas/psicologia , Desempenho Atlético/psicologia , Imagens, Psicoterapia , Autoeficácia , Análise Fatorial , Feminino , Humanos , Masculino , Motivação , Inquéritos e Questionários , Adulto Jovem
19.
Sci Adv ; 1(2): e1500052, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26601154

RESUMO

We conducted an analysis of global forest cover to reveal that 70% of remaining forest is within 1 km of the forest's edge, subject to the degrading effects of fragmentation. A synthesis of fragmentation experiments spanning multiple biomes and scales, five continents, and 35 years demonstrates that habitat fragmentation reduces biodiversity by 13 to 75% and impairs key ecosystem functions by decreasing biomass and altering nutrient cycles. Effects are greatest in the smallest and most isolated fragments, and they magnify with the passage of time. These findings indicate an urgent need for conservation and restoration measures to improve landscape connectivity, which will reduce extinction rates and help maintain ecosystem services.

20.
J Invest Dermatol ; 106(6): 1273-6, 1996 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8752669

RESUMO

The Ehlers-Danlos syndrome (EDS) is a heterogeneous group of inherited connective tissue disorders in which cutaneous fragility and ligamentous laxity often combine with vascular, gastrointestinal, and skeletal deformities. There is considerable phenotypic overlap between the more common forms of EDS (types I and II), in which specific molecular defects have not yet been identified. Recently, genetic linkage has been demonstrated between the COL5A1 gene, which encodes the alphal chain of type V collagen, and EDS type II in a large British kindred. Using a polymorphic intragenic simple sequence repeat at the COL5A1 locus, we now demonstrate tight linkage to EDS type I/II in a three-generation family, giving a LOD score (log10 of the odds for linkage) of 4.07 at zero recombination. The variation in expression in this family suggests that EDS types I and II are allelic, and the linkage data support the hypothesis that mutation in COL5A1 can cause both phenotypes.


Assuntos
Colágeno/genética , Síndrome de Ehlers-Danlos/genética , Genes , Ligação Genética , Idoso , Colágeno/ultraestrutura , Síndrome de Ehlers-Danlos/patologia , Feminino , Humanos , Microscopia Eletrônica , Linhagem , Sequências Repetitivas de Ácido Nucleico , Pele/metabolismo , Pele/patologia
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