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1.
Proc Biol Sci ; 284(1865)2017 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-29046384

RESUMO

The utility of marine protected areas (MPAs) as a means of protecting exploited species and conserving biodiversity within MPA boundaries is supported by strong empirical evidence. However, the potential contribution of MPAs to fished populations beyond their boundaries is still highly controversial; empirical measures are scarce and modelling studies have produced a range of predictions, including both positive and negative effects. Using a combination of genetic parentage and relatedness analysis, we measured larval subsidies to local fisheries replenishment for Australasian snapper (Chrysophrys auratus: Sparidae) from a small (5.2 km2), well-established, temperate, coastal MPA in northern New Zealand. Adult snapper within the MPA contributed an estimated 10.6% (95% CI: 5.5-18.1%) of newly settled juveniles to surrounding areas (approx. 400 km2), with no decreasing trend in contributions up to 40 km away. Biophysical modelling of larval dispersal matched experimental data, showing larvae produced inside the MPA dispersed over a comparable distance. These results demonstrate that temperate MPAs have the potential to provide recruitment subsidies at magnitudes and spatial scales relevant to fisheries management. The validated biophysical model provides a cost-efficient opportunity to generalize these findings to other locations and climate conditions, and potentially informs the design of MPA networks for enhancing fisheries management.


Assuntos
Distribuição Animal , Conservação dos Recursos Naturais , Pesqueiros , Perciformes/fisiologia , Animais , Hidrodinâmica , Modelos Teóricos , Nova Zelândia , Perciformes/genética , Perciformes/crescimento & desenvolvimento , Dinâmica Populacional
2.
Pediatr Cardiol ; 36(3): 633-9, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25410823

RESUMO

Although exercise stress echocardiography (ESE) is a well-validated technique in adult population, its use in children is quite limited. We aimed to assess the feasibility, the safety and the reproducibility of ESE, using on-line scanning in semi-supine cyclo-ergometer protocol in a large pediatric population. Between July 2008 and January 2013, 42 patients (mean age 14 ± 3) were evaluated with a bicycle ESE performing 50 studies. ESE was successfully performed and well tolerated by all patients. None of the patients presented with adverse effects of stress-induced ischemia. HR was 82 ± 13 at rest, and 153 ± 19.1 during peak exercise. Among 544 views analyzed for grading of image quality, the visualization was optimal in 473 (87 %), suboptimal in 39, and inadequate in 32 (6 %). 37 tests were performed in patients with congenital or acquired coronary abnormality. Regional wall motion abnormalities (RWMA) were revealed in nine cases (24 %). The agreement between the two different observers showed a K index of 0.7276 (95 % CI 0.6497-0.8055) for the image quality and a K index of 0.5125 (95 % CI 0.4782-0.5468) for the RWMA analysis. Among ten patients with hypertrophic cardiomyopathy, we were able to demonstrate the new comparison of significant left ventricular outflow tract gradient (≥30 mmHg) during exercise in three patients (30 %). Bicycle stress echocardiography performed by on-line scanning during exercise is a feasible, safe, and reproducible modality in children. Further data to assess its diagnostic accuracy are, however, needed. Stress echocardiography provides a dynamic assessment of the myocardial structure and function under conditions of physiologic or pharmacologic stress.


Assuntos
Ecocardiografia sob Estresse/métodos , Teste de Esforço/métodos , Coração/anatomia & histologia , Coração/fisiologia , Coração/fisiopatologia , Adolescente , Cardiomiopatia Hipertrófica/diagnóstico por imagem , Cardiomiopatia Hipertrófica/fisiopatologia , Criança , Vasos Coronários/diagnóstico por imagem , Feminino , Humanos , Masculino , Medição de Risco , Decúbito Dorsal , Função Ventricular Esquerda/fisiologia
3.
J Chem Phys ; 140(17): 174710, 2014 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-24811658

RESUMO

Crystalline and quasicrystalline allotropes of Pb are formed by evaporation on the fivefold surface of the icosahedral (i) Ag-In-Yb quasicrystal under ultra-high vacuum. Lead grows in three dimensional quasicrystalline order and subsequently forms fivefold-twinned islands with the fcc(111) surface orientation atop of the quasicrystalline Pb. The islands exhibit specific heights (magic heights), possibly due to the confinement of electrons in the islands. We also study the adsorption behavior of C60 on the two allotropes of Pb. Scanning tunneling microcopy reveals that a high corrugation of the quasicrystalline Pb limits the diffusion of the C60 molecules and thus produces a disordered film, similar to adsorption behavior of the same molecules on the clean substrate surface. However, the sticking coefficient of C60 molecules atop the Pb islands approaches zero, regardless of the overall C60 coverage.

4.
Nat Commun ; 4: 2715, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24185350

RESUMO

Quasicrystals, materials with aperiodic long-range order, have been found in intermetallics, soft materials such as colloids and supermolecules, and also in two-dimensional monolayer films. Here we present the first example of three-dimensional growth of a single-element quasicrystalline film. Using a hitherto unexplored template, the icosahedral Ag-In-Yb quasicrystal, and various experimental techniques combined with theoretical calculations of adsorption energies, we find that lead atoms deposited on the surface occupy the positions of atoms in the rhombic triacontahedral cluster, the building block of the substrate, and thus grow in layers with different heights and adsorption energies. We show that the adlayer-adlayer interaction is crucial for stabilizing this epitaxial quasicrystalline structure. The finding opens an avenue for further investigation of the impact of the aperiodic atomic order over periodic order on the physical and chemical properties of materials.

5.
J Phys Condens Matter ; 25(39): 395007, 2013 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-24018417

RESUMO

Scanning tunneling microscopy and x-ray photoemission spectroscopy on a polygrain icosahedral (i-) Al­Pd­Re quasicrystal (QC) show the formation of the twofold surfaces with symmetry and composition expected from the bulk. The predominant occurrence of the twofold surface on the polygrain i-QC having random grain orientation, as well as preferential formation of terrace edges, kinks and voids along the twofold axes, consistently indicates that the twofold surface, which has the highest atomic density, is the most stable among all the crystallographic planes.

6.
J Phys Condens Matter ; 24(43): 435502, 2012 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-23032482

RESUMO

The growth of Bi on Ag(111) induces different surface structures, including (√3 × âˆš3)R30° surface alloy, Bi-(p × âˆš3) overlayer and Bi(110) thin film, as a function of increasing Bi coverage. Here we report the study of electronic states of these structures using core level and valence band photoemission spectroscopy at room temperature. The sp-derived Shockley surface state on Ag(111) is rapidly quenched upon deposition of Bi, due to the strong variation of the in-plane surface potential in the Ag(2)Bi surface alloy. The Bi 4f core levels of the (√3 × âˆš3)R30° alloy and Bi(110) thin film are shifted to lower binding energy by ~0.6 eV and ~0.3 eV compared with the Bi bulk value, respectively. Mechanisms inducing the core level shifts are discussed as due to a complex superposition of several factors. As Bi coverage increases and a Bi(110) overlayer forms on Ag(111), a new state is observed at ~0.9 ML arising from electronic states localized at the Ag-Bi interface. Finally the change of work function as a function of coverage is discussed on the basis of a charge transfer model.


Assuntos
Bismuto/química , Espectroscopia Fotoeletrônica/métodos , Prata/química , Ligas , Eletrônica , Elétrons , Teste de Materiais , Física/métodos , Propriedades de Superfície
7.
J Phys Condens Matter ; 23(26): 265006, 2011 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-21666301

RESUMO

The deposition of 1/3 of a monolayer of Pb on Ag(111) leads to the formation of PbAg(2) surface alloy with a long range ordered (√3 × âˆš3)R30° superstructure. A detailed analysis of this structure using low-energy electron diffraction (LEED) I-V measurements together with density functional theory (DFT) calculations is presented. We find strong correlation between experimental and calculated LEED I-V data, with the fit between the two data sets having a Pendry's reliability factor of 0.21. The Pb atom is found to replace one top layer Ag atom in each unit cell, forming a substitutional PbAg(2) surface alloy, as expected, with the Pb atoms residing approximately 0.4 Å above the Ag atoms due to their size difference. DFT calculations are in good agreement with the LEED results.

8.
Int J Eat Disord ; 27(3): 335-40, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10694720

RESUMO

OBJECTIVE: To determine whether there are seasonal fluctuations in eating pathology in a nonclinical population. METHOD: The Eating Attitudes Test (EAT) was completed by 322 subjects during winter and again during summer. Summer and winter responses were compared to investigate differences in EAT total and subscale scores and for individual EAT items. Numbers of subjects fluctuating across the seasons by more than 2 SDs of the cohort's scores were identified. RESULTS: The cohort showed no significant seasonal change on EAT-40 totals, EAT-26 totals, or within the EAT subscales. There were significant (p <.025) seasonal fluctuations on four of the EAT-40 questions. For individual respondents, there was no greater likelihood of scoring significantly higher in the winter than in the summer. DISCUSSION: Clinically significant seasonal fluctuations in eating pathology on the EAT did not occur in this nonclinical population. It is debatable whether items within the EAT which show significant seasonal fluctuations should be retained or discarded.


Assuntos
Atitude , Transtornos da Alimentação e da Ingestão de Alimentos/diagnóstico , Estações do Ano , Adulto , Estudos de Coortes , Transtornos da Alimentação e da Ingestão de Alimentos/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Inquéritos e Questionários
9.
Br J Psychiatry ; 171: 53-5, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9328495

RESUMO

BACKGROUND: Little is known about seasonal fluctuations in psychological well-being among elderly people. METHOD: Over a period of 21 months, 1466 elderly people completed the General Health Questionnaire and the Leeds Scales for Depression and Anxiety. Scores during the winter months (December to February) were compared with those during other months of the year. RESULTS: Scores on all scales were significantly higher during the winter months, but there was no difference in rates of caseness. Unlike younger populations, elderly women did not exhibit greater seasonality in well-being than did elderly men. CONCLUSIONS: Elderly people exhibit a small seasonal fluctuation in psychological well-being, which is probably of little clinical importance, and there is no gender difference. The findings support the contention that seasonal mood changes are most pronounced among females of reproductive age.


Assuntos
Saúde Mental , Transtorno Afetivo Sazonal/epidemiologia , Estações do Ano , Fatores Etários , Idoso , Análise de Variância , Estudos de Coortes , Feminino , Humanos , Masculino , Fatores Sexuais
13.
Hum Reprod ; 7(9): 1240-4, 1992 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1479005

RESUMO

The clinical value of two inexpensive and easy to perform sperm function tests (hypo-osmotic swelling and bovine sperm mucus penetration tests) were examined in a prospective study of in-vivo conception rates in 325 couples. Both tests were of no significant value alone or in combination with traditional semen characteristics in predicting pregnancy outcome. The two most predictive factors of conception were the length of infertility and percentage of progressively motile spermatozoa. Our data support the further investigation of sperm function using more sophisticated quantitative tests, specifically the examination of sperm motility.


Assuntos
Muco do Colo Uterino , Infertilidade Masculina/diagnóstico , Motilidade dos Espermatozoides , Espermatozoides/fisiologia , Adulto , Feminino , Seguimentos , Humanos , Tábuas de Vida , Masculino , Pessoa de Meia-Idade , Osmose , Valor Preditivo dos Testes , Gravidez , Estudos Prospectivos , Análise de Regressão , Contagem de Espermatozoides
14.
Hum Reprod ; 7(1): 95-8, 1992 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-1551968

RESUMO

The clinical significance of antisperm antibodies for fertility remains controversial. In this study, we determined whether the presence, isotype, region and/or amount of sperm-bound antibody was of any predictive value for future fertility in 534 men using Cox's proportional hazards model. Significant correlations between the presence of antibodies and semen parameters were recorded, such as sperm mucus penetration and sperm motility. However, low (less than 10%) negative binding and moderate (less than 50%) binding had no significant effect on the probability of conception or the time to conception. This study confirms in-vitro data suggesting that sperm function is not impaired unless the degree of antibody binding to spermatozoa is very high.


Assuntos
Anticorpos/imunologia , Infertilidade Masculina/imunologia , Capacitação Espermática , Espermatozoides/imunologia , Autoimunidade , Fertilização , Humanos , Masculino , Prognóstico , Sêmen/imunologia
16.
Chest ; 90(5): 698-702, 1986 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-3533454

RESUMO

Propafenone is a new membrane-stabilizing antiarrhythmic agent that structurally resembles the beta-adrenergic receptor antagonist, propranolol. To determine the potential asthmogenicity of this new drug, pulmonary function, airway reactivity to methacholine, blood pressure, the electrocardiogram, and plasma concentrations were measured in 12 patients with mild intermittent asthma after 48 to 72 hours of treatment with placebo and with oral propafenone in low dosage (150 mg every eight hours) and high dosage (300 mg every eight hours) in a double-blind crossover manner. The forced vital capacity (FVC), forced expiratory volume in one second (FEV1), forced expiratory flow over the middle half of the FVC (FEF25-75%), heart rate, and blood pressure during the three regimens of treatment were not significantly different; however, the QRS interval on the ECG was significantly widened with both dosages of active drug, and the mean provocative dose of methacholine (+/- SE) required to reduce FEV1 by 20 percent (PD20) decreased from 3.0 +/- 0.6 mg/ml with placebo to 2.1 +/- 0.7 mg/ml with the high dosage of propafenone (p less than 0.01). The mean PD20 on the low-dose regimen was not significantly different from placebo or high-dose therapy. A potentially relevant increase in airway reactivity, as measured by a ratio of less than 0.5 for PD20 after treatment to PD20 after placebo, occurred in seven subjects with high-dose and in one subject during low-dose treatment (p less than 0.01). These data suggest that propafenone should be used with caution in patients with asthma and that bronchial provocation will provide a more sensitive measure of the asthmogenicity of a drug with beta-adrenergic receptor antagonist activity than pulmonary function tests. Moreover, use of bronchial provocation allows the selection of subjects with mild disease, thus reducing the risk of potentially severe bronchospasm.


Assuntos
Asma/induzido quimicamente , Propafenona/efeitos adversos , Adulto , Volume Expiratório Forçado , Coração/efeitos dos fármacos , Humanos , Cloreto de Metacolina , Compostos de Metacolina , Propafenona/sangue
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