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1.
Phys Rev Lett ; 128(1): 011801, 2022 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-35061499

RESUMO

Dark matter with Planck-scale mass (≃10^{19} GeV/c^{2}) arises in well-motivated theories and could be produced by several cosmological mechanisms. A search for multiscatter signals from supermassive dark matter was performed with a blind analysis of data collected over a 813 d live time with DEAP-3600, a 3.3 t single-phase liquid argon-based detector at SNOLAB. No candidate signals were observed, leading to the first direct detection constraints on Planck-scale mass dark matter. Leading limits constrain dark matter masses between 8.3×10^{6} and 1.2×10^{19} GeV/c^{2}, and ^{40}Ar-scattering cross sections between 1.0×10^{-23} and 2.4×10^{-18} cm^{2}. These results are interpreted as constraints on composite dark matter models with two different nucleon-to-nuclear cross section scalings.

2.
Eur Phys J C Part Fields ; 81(9): 823, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34720726

RESUMO

The DEAP-3600 detector searches for the scintillation signal from dark matter particles scattering on a 3.3 tonne liquid argon target. The largest background comes from 39 Ar beta decays and is suppressed using pulse-shape discrimination (PSD). We use two types of PSD estimator: the prompt-fraction, which considers the fraction of the scintillation signal in a narrow and a wide time window around the event peak, and the log-likelihood-ratio, which compares the observed photon arrival times to a signal and a background model. We furthermore use two algorithms to determine the number of photons detected at a given time: (1) simply dividing the charge of each PMT pulse by the mean single-photoelectron charge, and (2) a likelihood analysis that considers the probability to detect a certain number of photons at a given time, based on a model for the scintillation pulse shape and for afterpulsing in the light detectors. The prompt-fraction performs approximately as well as the log-likelihood-ratio PSD algorithm if the photon detection times are not biased by detector effects. We explain this result using a model for the information carried by scintillation photons as a function of the time when they are detected.

3.
Rev Med Liege ; 76(11): 794-798, 2021 Nov.
Artigo em Francês | MEDLINE | ID: mdl-34738752

RESUMO

Therapeutic education is defined as all the tools taught to patients with the aim of improving their compliance to treatments. In a chronic disease, such as cystic fibrosis, this education should be done during the first months of child's life with the collaboration of parents and then gradually given to children from the age of 6 until they are autonomous in the management of their treatment during adolescence. The tools used for therapeutic education should be playful, varied and adapted to the child's development, while respecting a standard for competences. In this article, we will define the main approaches of therapeutic education in patients with cystic fibrosis.


L'éducation thérapeutique se définit comme l'ensemble des outils enseignés aux patients dans le but d'améliorer leur adhésion aux traitements. Lors d'une maladie chronique, telle que la mucoviscidose, cet appren¬tissage doit être réalisé dès les premiers mois de vie de l'enfant avec ses parents. Elle se transmet ensuite progres¬sivement vers l'enfant à partir de l'âge de 6 ans afin de l'au¬tonomiser à l'adolescence. Les moyens aidant à réaliser cette éducation thérapeutique doivent être ludiques, variés et adaptés au développement de l'enfant, tout en respec¬tant un référentiel de compétences. Dans cet article, nous retraçons les grandes lignes de l'éducation thérapeutique dans la prise en charge de la mucoviscidose.


Assuntos
Fibrose Cística , Adolescente , Criança , Doença Crônica , Fibrose Cística/terapia , Humanos , Pais , Cooperação do Paciente
4.
Phys Rev Lett ; 121(7): 071801, 2018 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-30169081

RESUMO

This Letter reports the first results of a direct dark matter search with the DEAP-3600 single-phase liquid argon (LAr) detector. The experiment was performed 2 km underground at SNOLAB (Sudbury, Canada) utilizing a large target mass, with the LAr target contained in a spherical acrylic vessel of 3600 kg capacity. The LAr is viewed by an array of PMTs, which would register scintillation light produced by rare nuclear recoil signals induced by dark matter particle scattering. An analysis of 4.44 live days (fiducial exposure of 9.87 ton day) of data taken during the initial filling phase demonstrates the best electronic recoil rejection using pulse-shape discrimination in argon, with leakage <1.2×10^{-7} (90% C.L.) between 15 and 31 keV_{ee}. No candidate signal events are observed, which results in the leading limit on weakly interacting massive particle (WIMP)-nucleon spin-independent cross section on argon, <1.2×10^{-44} cm^{2} for a 100 GeV/c^{2} WIMP mass (90% C.L.).

5.
Rev Mal Respir ; 33(5): 350-64, 2016 May.
Artigo em Francês | MEDLINE | ID: mdl-26657587

RESUMO

INTRODUCTION: Poor asthma knowledge among asthmatic patients contributes to poor control of the disease. Education is a priority, but it needs a good assessment of the patient's knowledge. AIM: To give a patient's knowledge questionnaire development method following the example of the Questionnaire de Connaissances sur l'Asthme destiné aux Patients Adultes (QCA-PA). METHODS: The QCA-PA was developed according to Dussault, Valois and Frenette's seven steps and includes 54 "true/false/don't know" items. A total of 101 asthmatic adults completed the questionnaire four times during three visits over a period of about one month. On the second visit, it was answered twice, before and after an individualized education session on asthma. RESULTS: The QCA-PA demonstrates different proofs of validity: content, response process, internal structure, relationship to other variables, and consequences of testing. Confirmatory factorial analysis showed a unidimensional structure. CONCLUSIONS: QCA-PA is a new rigorously validated knowledge measurement tool based on the most recent international recommendations. It could help health professionals to better target their educational interventions towards asthma patients.


Assuntos
Asma , Conhecimento , Inquéritos e Questionários , Adulto , Asma/etiologia , Asma/terapia , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Educação de Pacientes como Assunto , Índice de Gravidade de Doença , Fatores Socioeconômicos
6.
Clin Exp Allergy ; 45(11): 1647-53, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26115509

RESUMO

BACKGROUND: The allergen bronchoprovocation (ABP) test is a validated model to study asthma pathophysiology and response to treatments. The inhibitory effect of agents on the allergen-induced late asthmatic response (LAR) is a predictor of their efficacy in asthma treatment. However, it is difficult to predict the magnitude of a LAR, which may vary according to immune responsiveness and the type of allergen used for ABP. AIM: To determine the relationship between the magnitudes of early asthmatic response (EAR) and LAR in mild asthmatic subjects according to the type of allergen inhaled and its determinants. METHODS: This is a retrospective analysis of a large database of ABPs, all performed with a common standardized methodology. Patients were either challenged with house dust mites (HDMs), animals or pollens allergens. EAR was defined as a ≥ 20% fall in forced expiratory volume in 1 s (FEV1 ) < 3 h following ABP and LAR as a ≥ 15% fall in FEV1 between 3 and 7 h post-ABP. The ratio of EAR % fall in FEV1 /LAR % fall in FEV1 was compared between the groups of subjects according to the allergen used for ABP. RESULTS: Data from 290 subjects were analysed: 87 had an isolated EAR and 203 had a dual response (EAR + LAR). Dual responders had a significantly lower baseline PC20 , a more marked fall in FEV1 at EAR, and a trend towards higher baseline sputum eosinophil percentages. The ratio of EAR over LAR was significantly lower in HDM compared with pollen ABP, indicating a larger LAR for a similar EAR. No correlations were observed between the ratio of EAR over LAR and the various parameters recorded in the different groups analysed. CONCLUSION: Different mechanisms may be involved in modulating the magnitude of the LAR, according to the type of allergen. HDM seems to induce a stronger LAR than pollens, animal allergens being intermediary in this regard.


Assuntos
Alérgenos/imunologia , Asma/imunologia , Estações do Ano , Adulto , Asma/diagnóstico , Asma/fisiopatologia , Testes de Provocação Brônquica , Eosinófilos/imunologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes de Função Respiratória , Estudos Retrospectivos , Escarro/imunologia , Adulto Jovem
7.
J Anim Sci ; 92(9): 3816-24, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25006074

RESUMO

Genetic parameters for ultimate pH of pectoralis major muscle (PM-pHu) and sartorius muscle (SART-pHu); color parameters L*, a*, b*; logarithm of drip loss (LogDL) of pectoralis major (PM) muscle; breast meat yield (BMY); thigh and drumstick yield (TY); abdominal fat percentage (AFP); and BW at 6 wk (BW6) were estimated in 2 lines of broiler chickens divergently selected for PM-pHu. Effects of selection on all the previous traits and on glycolytic potential, pectoralis major muscle pH at 15 min postmortem, curing-cooking yield (CCY), cooking loss (CL), and Warner-Bratzler shear force (WBSF) of the PM muscle were also analyzed after 5 generations. Strong genetic determinism of PM-pHu was observed, with estimated h(2) of 0.57 ± 0.02. There was a significant positive genetic correlation (rg) between PM-pHu and SART-pHu (0.54 ± 0.04), indicating that selection had a general rather than a specific effect on energy storage in skeletal muscles. The h(2) estimates of L*, a*, and b* parameters were 0.58 ± 0.02, 0.39 ± 0.02, and 0.48 ± 0.02, respectively. Heritability estimates for TY, BMY, and AFP were 0.39 ± 0.04, 0.52 ± 0.01, and 0.71 ± 0.02, respectively. Our results indicated different genetic control of LogDL and L* of the meat between the 2 lines; these traits had a strong rg with PM-pHu in the line selected for low ultimate pH (pHu) value (pHu-; -0.80 and -0.71, respectively), which was not observed in the line selected for high pHu value (pHu+; -0.04 and -0.29, respectively). A significant positive rg (0.21 ± 0.04) was observed between PM-pHu and BMY but not between PM-pHu and BW6, AFP, or TY. Significant phenotypic differences were observed after 5 generations of selection between the 2 lines. The mean differences (P < 0.001) in pHu between the 2 lines were 0.42 and 0.21 pH units in the breast and thigh muscle, respectively. Breast meat in the pHu+ line exhibited lower L* (-5 units; P < 0.001), a* (-0.22 units; P < 0.001), b* (-1.53 units; P < 0.001), and drip loss (-1.6 units; P < 0.001) than in the pHu- line. Breast meat of the pHu+ line was also characterized by greater CCY (+6.1 units; P < 0.001), lower CL (-1.66 units; P < 0.01), and lower WBSF after cooking (-5.1 units; P < 0.001) compared to the pHu- line. This study highlighted that selection based on pHu can be effective in improving the processing ability of breast meat and reducing the incidence of meat quality defects without affecting chicken growth performance.


Assuntos
Composição Corporal/genética , Carne/normas , Músculo Esquelético/fisiologia , Animais , Galinhas/genética , Galinhas/fisiologia , Glicólise/genética , Concentração de Íons de Hidrogênio , Fenótipo , Seleção Genética
8.
J Nutr Health Aging ; 17(4): 385-9, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23538663

RESUMO

CONTEXT: Some studies have highlighted the difficulty for physicians to evaluate patient's ability to consent to bio-medical research in the elderly population. The University of California Brief Assessment of Capacity to Consent (UBACC) is a rapid questionnaire to assess the ability to consent, previously validated among schizophrenic patients. OBJECTIVE: To evaluate the accuracy of the UBACC scale, French version, to determine the capacity to consent to biomedical studies of older people with normal cognition, mild cognitive impairment (MCI) or Alzheimer Disease (AD). DESIGN: A prospective validation study between September 2008 to November 2011. SETTING: A Memory clinic. PATIENTS: We included 61 subjects in a memory clinic who had already consented to participate to a biomedical research and had signed a consent form. Those subjects, who had memory impairment, had a comprehensive neuro-psychological (including Mini Mental State Examination (MMSE)/30), clinical, biological assessment and brain imagery during day-care hospital. They were classified as MCI or AD patients. Control group included patients' caregivers without memory complaints and a normal comprehensive neuro-psychological assessment. INTERVENTION AND MEASUREMENTS: The consent form was once again explained to the subjects by a physician who subjectively evaluated if subjects had understood the study. Then, the 10 questions of the French version of the UBACC scale (max score 20) were asked to the participants. This scale evaluates the understanding of the study's aim, risks and benefits. A comparison was made between subjective assessment and the UBACC score. RESULTS: The physician considered that 18/61 patients (2 MCI and 16 AD) had not understood. These ones had a lower UBACC score (Score/20 (SD) [range]: 7.56 (3.03) [0-12] versus 17.72 (2.68) [13-28], p<0.001), a lower MMSE (Score/ 30 (SD): 21.1 (5.9) versus 27.3 (2.9); p<0.001) and were older (age (years old) 80.8 versus 76.6. p<0.0001) compared to those who had understood. Moreover, all the patients who had not understood had an UBACC score ≤ 12. The administration time was accurate in this population (<10 minutes). CONCLUSION: The UBACC scale, in its French version, was accurate to assess capacity to consent in an older, cognitively impaired population.


Assuntos
Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/psicologia , Inquéritos e Questionários , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer , Pesquisa Biomédica , Feminino , Humanos , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/sangue , Fator de Crescimento Insulin-Like I/análise , Fator de Crescimento Insulin-Like I/metabolismo , Idioma , Masculino , Testes Neuropsicológicos , Estudos Prospectivos
9.
Scand J Med Sci Sports ; 21(6): 841-5, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20536908

RESUMO

Maximal oxygen uptake (VO2max) is one of the most important determinants of elite endurance performance. VO2max is determined by a whole range of genetic and environmental factors. Single nucleotide polymorphisms (SNPs) in muscle myostatin (MSTN) and creatine kinase (CKM) genes are candidates for VO2max and skeletal muscle performance phenotypes. Common MSTN (rs3791783, rs11681628 and rs7570532) and CKM (rs344816, rs10410448, rs432979, rs1133190, rs7260359, rs7260463 and rs4884) SNPs, selected from HapMap CEU data in order to tag the genetic variability of the proteins, were genotyped in 316 male Caucasian elite endurance athletes and 304 sedentary controls from the Genathlete study. Association with elite endurance performance was determined by logistic regression analysis. The P-value for statistical significance was set at <0.01. None of the SNPs or haplotypes showed a significant association with elite endurance status. We conclude that common variants of MSTN and CKM genes do not play a role in attaining high-level endurance performance in Caucasian populations.


Assuntos
Desempenho Atlético/fisiologia , Creatina Quinase Forma MM/genética , Miostatina/genética , Resistência Física/genética , Polimorfismo de Nucleotídeo Único/genética , Creatina Quinase Forma MM/metabolismo , Genótipo , Humanos , Masculino , Miostatina/metabolismo , Consumo de Oxigênio/genética , Consumo de Oxigênio/fisiologia
10.
Phytopathology ; 100(5): 424-31, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20373962

RESUMO

Plant infection by pathogens generates various forms of symptoms. Most of them have been described as soon as they become visible, whereas preceding, discrete signs during incubation are poorly or not understood. In Vitis vinifera, esca-related pathogenic fungi inhabit living trunk wood and induce the so-called apoplexy, a sudden wilting of leaves within a few days. To further understand the apoplexy expression, the period preceding symptom appearance was investigated by following physiological and molecular markers associated with photosynthetic mechanisms and stress responses. Within the week preceding symptoms, drastic physiological alterations of photosynthesis were registered in pre-apoplectic vines, as revealed by a decrease in gas exchange, changes in chlorophyll fluorescence, and repression of photosynthesis-related genes. In the meantime, expression of defense-related genes was induced and amplified during symptom expression. Water-stress-related genes were specifically investigated because water transport may be impeded by clogging xylem vessels due to esca-causing fungi. Neither of the tested water-stress-related genes was affected in pre-apoplectic grapevine leaves whereas these genes were downregulated in drying leaves. Our results suggest that, during incubation of esca apoplexy, grapevine perceives some signals (likely fungi-originated toxins) and reacts by reducing photosynthesis and triggering defense mechanisms.


Assuntos
Fungos/fisiologia , Doenças das Plantas/microbiologia , Folhas de Planta/microbiologia , Vitis/microbiologia , Clorofila/genética , Clorofila/metabolismo , Clorofila A , Fluorescência , Regulação da Expressão Gênica de Plantas/fisiologia , Fotossíntese/fisiologia , Vitis/metabolismo
11.
J Nutr Health Aging ; 14(1): 31-5, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20082051

RESUMO

PURPOSE: This paper examines and reviews studies on the efficacy of computer-based cognitive intervention programmes in the elderly affected by Mild Cognitive Impairment (MCI). MCI patients are at higher risk to progress to dementia. Recent effort has been made to slow the cognitive decline and delay the onset of dementia in this population. METHOD: MEDLINE sources were searched with the following subject headings: computer-based cognitive intervention, cognitive stimulation, cognitive training, aging, elderly, cognitive impairment. Selected studies were quality assessed and data extracted by two reviewers. RESULTS: Several studies reported encouraging results on cognitive interventions programmes as a means to improve cognitive abilities and emotional states and to decrease subjective memory complaints in MCI patients. CONCLUSION: Though both traditional and computer-based cognitive intervention programmes seem to be effective, the computer-based ones present more advantages: 1) they could individualize the programme tailored to the patient's neuropsychological pattern and needs. 2) they permit the user to make an immediate objective comparison with data collected earlier and thus help in setting up a systematic training plan by providing instant value-free feedback. 3) they offer a possibility of a widescale dissemination.


Assuntos
Transtornos Cognitivos/terapia , Avaliação de Processos e Resultados em Cuidados de Saúde , Idoso , Idoso de 80 Anos ou mais , Transtornos Cognitivos/prevenção & controle , Computadores , Demência/prevenção & controle , Feminino , Humanos , Masculino , Resultado do Tratamento
12.
Phys Rev Lett ; 101(11): 111301, 2008 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-18851271

RESUMO

The Sudbury Neutrino Observatory (SNO) used an array of 3He proportional counters to measure the rate of neutral-current interactions in heavy water and precisely determined the total active (nu_x) 8B solar neutrino flux. This technique is independent of previous methods employed by SNO. The total flux is found to be 5.54_-0.31;+0.33(stat)-0.34+0.36(syst)x10(6) cm(-2) s(-1), in agreement with previous measurements and standard solar models. A global analysis of solar and reactor neutrino results yields Deltam2=7.59_-0.21;+0.19x10(-5) eV2 and theta=34.4_-1.2;+1.3 degrees. The uncertainty on the mixing angle has been reduced from SNO's previous results.

13.
Int J Tuberc Lung Dis ; 12(7): 813-9, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18544209

RESUMO

OBJECTIVE: To evaluate the usefulness of fibrogenic cytokines and mediators in the analysis of induced sputum and determine if their levels correlated with previous decline in lung function in asbestosis and silicosis. DESIGN: In a pilot study for the evaluation of 19 workers with asbestosis and 15 with silicosis, all workers had chart reviews and records of previous lung function tests. Fourteen healthy control subjects were also included in the study. All subjects attended the laboratory for a clinical evaluation, pulmonary function tests and induced sputum sampling. Differential cell counts were performed and the following mediators and cytokines were measured: matrix metalloproteinase 9 (MMP-9), tissue inhibitor of metalloproteinases 1 (TIMP-1), fibronectin, interleukin 1 beta (IL-1beta), IL-6, IL-8, IL-12, transforming growth factor beta (TGF-beta) and tumor necrosis factor-alpha (TNF-alpha). RESULTS: Levels of IL-1beta were higher in the sputum of subjects with asbestosis and silicosis than in controls. Eosinophils, neutrophils and IL-1beta levels were significantly correlated with the rate of decline in pulmonary function. CONCLUSION: The induced sputum levels of certain inflammatory cells and IL-1beta correlate with the decline in pulmonary function associated with asbestosis and silicosis. It remains to be established if these markers can help predict the clinical outcome of workers exposed to these mineral particles or fibers in a prospective study.


Assuntos
Asbestose/imunologia , Interleucina-1beta/análise , Fibrose Pulmonar/imunologia , Silicose/imunologia , Escarro/química , Idoso , Biomarcadores/análise , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Fibrose Pulmonar/fisiopatologia , Testes de Função Respiratória , Estudos Retrospectivos
14.
Scand J Med Sci Sports ; 18(4): 485-90, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18067521

RESUMO

In the Genathlete study, we examined the contribution of three polymorphisms in the endothelial nitric oxide synthase (NOS3) gene to discriminate elite endurance athletes (EEA) from sedentary controls (SC). The EEA group included a total of 316 Caucasian males with a VO2max >75 mL/kg. The SC group comprised 299 unrelated sedentary Caucasian males who had VO2max values below 50 mL/kg. The polymerase chain reaction technique was used to amplify a microsatellite (CA)(n) repeat in intron 13, a 27 bp repeat in intron 4 and a third fragment in exon 7 containing the Glu298Asp SNP. No difference was found between the EEA and SC groups for the 27 bp repeat and the Glu298Asp polymorphism. Chi-square analysis of the overall allelic distribution of the (CA)(n) repeat revealed no significant difference between the two groups (P=0.135). However, comparing carriers and non-carriers for the most common (CA)(n) repeat alleles, we found significant differences between SC and EEA, with more EEA subjects carrying the 164 bp allele (P=0.007). In summary, we found suggestive evidence that the 164 bp allele of the (CA)(n) repeat in intron 13 is associated with EEA status and may account for some of the differences between EEA and SC.


Assuntos
Óxido Nítrico Sintase Tipo III/genética , Resistência Física , Polimorfismo de Nucleotídeo Único , Esportes , Estudos de Casos e Controles , Humanos , Masculino , Reação em Cadeia da Polimerase
15.
Allergy ; 62(10): 1101-10, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17845579

RESUMO

Allergen bronchoprovocation tests have been used for more than two decades in the investigation of respiratory allergic diseases such as asthma and rhinitis. These bronchial challenges are now well standardized and can offer key information on the therapeutic potential of new agents and on their anti-inflammatory effects on the airways. Both standard and low-dose allergen provocations are safe when performed by experienced investigators and do not lead to persistent worsening of asthma or change in airway function. The evaluation of new therapeutic agents by these methods can also provide important information on the mechanisms of development and persistence of airway diseases.


Assuntos
Alérgenos , Anti-Inflamatórios/uso terapêutico , Asma/diagnóstico , Asma/tratamento farmacológico , Testes de Provocação Brônquica/métodos , Inflamação/tratamento farmacológico , Alérgenos/imunologia , Animais , Asma/sangue , Asma/imunologia , Broncoconstrição/efeitos dos fármacos , Broncoconstrição/imunologia , Humanos , Inflamação/sangue , Inflamação/imunologia , Modelos Imunológicos , Valor Preditivo dos Testes , Testes de Função Respiratória/métodos , Testes de Função Respiratória/normas , Rinite/sangue , Rinite/diagnóstico , Rinite/tratamento farmacológico , Rinite/imunologia , Testes Cutâneos/métodos , Testes Cutâneos/normas
16.
Phytopathology ; 96(10): 1060-6, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18943493

RESUMO

ABSTRACT To further understand the development of esca disease in grapevine, its physiological impact on plants grown in the vineyard was characterized, focusing mainly on photosynthesis. For this purpose, the state of the photosynthetic apparatus was evaluated in symptomatic and asymptomatic leaves in esca-infected grape plants, and wood carbohydrates stored in annual canes were assayed. In symptomatic leaves, esca greatly affected grapevine physiology. Foliar symptoms were associated with both stomatal closure and alteration of the photosynthetic apparatus as revealed by (i) a decrease in CO(2) assimilation, transpiration, and a significant increase in intercellular CO(2) concentration; (ii) a strong drop in both the maximum fluorescence yield and the effective Photosystem II quantum yield; and (iii) a reduction of total chlorophyll but a stable carotenoid content. On symptomatic canes, all these variables were affected more on leaves with symptoms than without symptoms, suggesting a gradation in photosynthesis disruptions in the plant according to the degree of symptom severity. In addition, canes of symptomatic plants had reduced carbohydrate reserves during the winter rest, whether they exhibit symptoms or not. The following year, the lower pool of reserves may contribute to a significant decrease in plant development, as well as a global loss in plant vigor.

17.
Phys Rev Lett ; 92(18): 181301, 2004 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-15169480

RESUMO

The Sudbury Neutrino Observatory has precisely determined the total active (nu(x)) 8B solar neutrino flux without assumptions about the energy dependence of the nu(e) survival probability. The measurements were made with dissolved NaCl in heavy water to enhance the sensitivity and signature for neutral-current interactions. The flux is found to be 5.21 +/- 0.27(stat)+/-0.38(syst) x 10(6) cm(-2) s(-1), in agreement with previous measurements and standard solar models. A global analysis of these and other solar and reactor neutrino results yields Deltam(2)=7.1(+1.2)(-0.6) x 10(-5) eV(2) and theta=32.5(+2.4)(-2.3) degrees. Maximal mixing is rejected at the equivalent of 5.4 standard deviations.

18.
Phys Rev Lett ; 92(10): 102004, 2004 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-15089201

RESUMO

Data from the Sudbury Neutrino Observatory have been used to constrain the lifetime for nucleon decay to "invisible" modes, such as n-->3nu. The analysis was based on a search for gamma rays from the deexcitation of the residual nucleus that would result from the disappearance of either a proton or neutron from 16O. A limit of tau(inv)>2 x 10(29) yr is obtained at 90% confidence for either neutron- or proton-decay modes. This is about an order of magnitude more stringent than previous constraints on invisible proton-decay modes and 400 times more stringent than similar neutron modes.

19.
Allergy ; 58(9): 945-9, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12911426

RESUMO

BACKGROUND: Determinants of changes in airway caliber after allergen challenge include nonallergic airway responsiveness, immune response and dose of allergen given. However, determinants of the airway inflammatory response to allergens remain to be determined. AIM: To assess the relationship between skin reactivity to airborne allergens and lower airway eosinophilic response to allergen exposure in asthma and allergic rhinitis. METHODS: Forty-two subjects with mild allergic asthma (mean age 24 years) and 14 nonasthmatic subjects with allergic rhinitis (mean age 25 years) had allergen skin prick tests and titration with the allergen chosen for subsequent challenge. On a second visit, 31 asthmatic subjects had a conventional challenge while 11 asthmatic subjects and all rhinitic subjects had a low-dose allergen challenge over four subsequent days. Induced sputum samples were obtained at 6 and 24 h after the conventional challenge and at days 2 and 4 of the low-dose challenge. RESULTS: In the asthmatic group, there was a weak correlation between wheal diameter induced by the concentration used for challenge and increase in eosinophils 6 h postconventional challenge (r = 0.372, P = 0.05), but no correlation was observed following the low-dose challenge. Rhinitic subjects showed a correlation between wheal diameter with the allergen dose used for bronchoprovocation and increase in eosinophils at day 2 of low dose (r = 0.608, P = 0.02). CONCLUSION: This study suggests that immediate immune responsiveness to allergen, assessed by the magnitude of the skin response, is a significant determinant of allergen-induced airway eosinophilia and can help to predict the airway inflammatory response.


Assuntos
Alérgenos/imunologia , Asma/imunologia , Eosinofilia/etiologia , Hipersensibilidade/complicações , Rinite/imunologia , Pele/imunologia , Adulto , Asma/etiologia , Testes de Provocação Brônquica , Eosinofilia/patologia , Humanos , Hipersensibilidade Imediata/diagnóstico , Hipersensibilidade Imediata/imunologia , Rinite/etiologia , Testes Cutâneos , Escarro/citologia
20.
Clin Exp Allergy ; 32(10): 1441-7, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12372123

RESUMO

BACKGROUND: Low-dose allergen challenge (LDAC) may be a useful tool for studying the capacity of allergens to induce airway inflammation in atopic subjects. OBJECTIVE: To evaluate lower airway inflammatory changes following repeated inhalation of very low doses of allergen (VLDAC) in non-asthmatic subjects with allergic rhinitis (NAAR) compared with mild allergic asthmatic subjects (AA). METHODS: Fourteen NAAR and 11 AA were seen out of the pollen season and had skin prick tests with common aeroallergens. Baseline spirometry (S) and methacholine challenge (MC) were done and blood and induced sputum (IS) differential cell counts were obtained. Each subject underwent VLDAC on four consecutive mornings with a relevant allergen. S, MC, and blood and IS samplings were repeated 6 h after the second and fourth VLDAC and one week later. RESULTS: Although there were, as expected, no changes in FEV1 or PC20 in either group, mean percentage eosinophils on IS were significantly increased in NAAR on day 2 of VLDAC and decreased in all but one subject on day 4, with a tendency to return to baseline levels one week later. In AA, there was a non-significant trend for sputum eosinophils to increase on day 2; four subjects showed a decrease of eosinophils on day 4 of VLDAC. There was a correlation between eosinophil cationic protein (ECP) levels and eosinophil counts in NAAR throughout the study. There were no variations in other sputum cells or blood inflammatory cells. CONCLUSION: VLDAC can increase the percentage of eosinophils in IS of NAAR subjects without associated respiratory symptoms nor physiological modifications. A reduction in eosinophilic response despite repeated exposure, more common in NAAR subjects, suggests an adaptation process that needs to be further evaluated.


Assuntos
Alérgenos , Asma/imunologia , Eosinófilos/imunologia , Rinite Alérgica Perene/imunologia , Escarro/imunologia , Adolescente , Adulto , Análise de Variância , Broncoconstritores , Relação Dose-Resposta Imunológica , Feminino , Humanos , Esquemas de Imunização , Masculino , Cloreto de Metacolina , Pessoa de Meia-Idade , Análise Multivariada , Espirometria
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