Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 38
Filtrar
1.
Phys Rev Lett ; 118(15): 151801, 2017 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-28452532

RESUMO

T2K reports its first results in the search for CP violation in neutrino oscillations using appearance and disappearance channels for neutrino- and antineutrino-mode beams. The data include all runs from January 2010 to May 2016 and comprise 7.482×10^{20} protons on target in neutrino mode, which yielded in the far detector 32 e-like and 135 µ-like events, and 7.471×10^{20} protons on target in antineutrino mode, which yielded 4 e-like and 66 µ-like events. Reactor measurements of sin^{2}2θ_{13} have been used as an additional constraint. The one-dimensional confidence interval at 90% for the phase δ_{CP} spans the range (-3.13, -0.39) for normal mass ordering. The CP conservation hypothesis (δ_{CP}=0, π) is excluded at 90% C.L.

2.
Phys Rev Lett ; 117(19): 192501, 2016 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-27858422

RESUMO

We report the first measurement of the flux-averaged cross section for charged current coherent π^{+} production on carbon for neutrino energies less than 1.5 GeV, and with a restriction on the final state phase space volume in the T2K near detector, ND280. Comparisons are made with predictions from the Rein-Sehgal coherent production model and the model by Alvarez-Ruso et al., the latter representing the first implementation of an instance of the new class of microscopic coherent models in a neutrino interaction Monte Carlo event generator. We observe a clear event excess above background, disagreeing with the null results reported by K2K and SciBooNE in a similar neutrino energy region. The measured flux-averaged cross sections are below those predicted by both the Rein-Sehgal and Alvarez-Ruso et al.

3.
Phys Rev Lett ; 116(18): 181801, 2016 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-27203315

RESUMO

T2K reports its first measurements of the parameters governing the disappearance of ν[over ¯]_{µ} in an off-axis beam due to flavor change induced by neutrino oscillations. The quasimonochromatic ν[over ¯]_{µ} beam, produced with a peak energy of 0.6 GeV at J-PARC, is observed at the far detector Super-Kamiokande, 295 km away, where the ν[over ¯]_{µ} survival probability is expected to be minimal. Using a data set corresponding to 4.01×10^{20} protons on target, 34 fully contained µ-like events were observed. The best-fit oscillation parameters are sin^{2}(θ[over ¯]_{23})=0.45 and |Δm[over ¯]_{32}^{2}|=2.51×10^{-3} eV^{2} with 68% confidence intervals of 0.38-0.64 and 2.26-2.80×10^{-3} eV^{2}, respectively. These results are in agreement with existing antineutrino parameter measurements and also with the ν_{µ} disappearance parameters measured by T2K.

4.
Trends Pharmacol Sci ; 19(7): 262-5, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9703758

RESUMO

The 18 UK universities offering three--of four--year BSc pharmacology courses were surveyed by questionnaire to determine course content, laboratory-practical content and project or dissertation requirements. In this article David Dewhurst and Clive Page provide an overview of the study, which highlighted the fact that there is no core curriculum. There was considerable variation in course content [only a limited number of common topics were taught in depth (> 15 h timetabled time)] and the time spent doing 'wet' laboratory practicals varied considerably (range 0-145 h). A research project in the final year was the norm (although the time allocation varied considerably), but some universities used a library-based dissertation as an alternative.


Assuntos
Currículo , Farmacologia/educação , Coleta de Dados , Educação de Graduação em Medicina , Farmacologia Clínica/educação , Reino Unido , Universidades
5.
Aust N Z J Psychiatry ; 30(3): 382-8; discussion 388-91, 1996 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8839950

RESUMO

OBJECTIVE: The aim of this paper is to provide a defence of diversity in psychiatry and, correspondingly, to show that strict 'biologism' (or any other 'total' approach to psychiatry) is inappropriate. METHOD: Arguments are developed using as a basis the writings of well known philosophers such as Stephen Toulmin, Joel Feinberg and Charles Taylor. The authors examine the concepts of explanation and causation and consider the consequences for psychiatry which might follow the acceptance of mind-brain identity. There is also a discussion of the concept of a person. RESULT: If the same phenomenon is subject to explanation from diverse psychiatric perspectives, it does not follow that these modes of explanation must exclude or be in competition with each other. They may in fact be necessary to each other if psychiatry is to provide a full picture of mental functioning and human conduct. The thesis of mind-brain identity does not eliminate the variety of discourses within psychiatry, and hence it does not provide a rationale for 'biologism'. CONCLUSION: There is a need for a co-operative multidimensional approach in psychiatry.


Assuntos
Filosofia Médica , Psiquiatria/tendências , Psiquiatria Biológica/tendências , Previsões , Humanos , Equipe de Assistência ao Paciente/tendências , Psicofisiologia
6.
Am J Physiol ; 267(6 Pt 3): S95-104, 1994 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-7998619

RESUMO

Here we describe an evaluation of the effectiveness, compared with a traditional laboratory, of an interactive computer-assisted learning (CAL) program, which simulates a series of experiments performed using isolated, everted sacs of rat small intestine. The program is aimed at undergraduate students of physiology and is designed to offer an alternative student-centered learning approach to the traditional laboratory-based practical class. The evaluative study compared two groups of second-year undergraduate students studying a module on epithelial transport: one group worked independently using the CAL program and associated learning materials, and the other group followed a conventional practical class approach, working in the laboratory under supervision. Knowledge gain of each group was measured by means of a test consisting of a range of question types (e.g., short-answer factual, calculation, interpretation) given to students before and after the module. Student attitude to both approaches was assessed by questionnaire, and the resource requirements were also compared. It was found that the knowledge gain of both groups of students was the same, that students had a positive attitude toward using CAL programs of this type, and that the cost of the conventional laboratory-based approach was five times greater. The potential for integrating CAL programs into the undergraduate curriculum is discussed.


Assuntos
Simulação por Computador , Absorção Intestinal , Fisiologia/educação , Materiais de Ensino , Alternativas aos Testes com Animais , Atitude , Estudos de Avaliação como Assunto , Laboratórios , Estudantes
7.
Am J Physiol ; 266(6 Pt 3): S2-9, 1994 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8017515

RESUMO

An interactive computer program written for IBM-compatible microcomputers, which simulates the physiological response to graded exercise in healthy individuals, is described. The program presents high-resolution graphic data (heart rate, pulmonary ventilation, oxygen consumption, and blood lactate concentration) in a form comparable to that of a chart recorder display. Data are derived from an empirical model that allows users to select certain parameters of the subject they wish to investigate, including sex, age, height, weight, and level of training. Measurements may be taken directly from the monitor screen by use of the cross-hair cursor facility provided. The program has been positively evaluated in use by undergraduate students and shown to be an effective teaching aid. The potential use of the software in light of these findings is discussed.


Assuntos
Simulação por Computador , Instrução por Computador , Exercício Físico/fisiologia , Modelos Cardiovasculares , Fisiologia/educação , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valores de Referência , Inquéritos e Questionários
8.
Australas Radiol ; 34(3): 219-22, 1990 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-2275679

RESUMO

Audited cost data from two public hospital installations participating in a trial of the utilisation and efficacy of magnetic resonance imaging are presented. The data cover the period July 1987 to June 1988 when both installations had attained stable patterns of operation. One hospital operated a superconductive system and the other a resistive magnetic resonance imaging unit. Depreciation and salaries represented the major components of cost.


Assuntos
Hospitais Públicos/economia , Imageamento por Ressonância Magnética/economia , Austrália , Gastos de Capital , Custos e Análise de Custo
10.
J Biomed Eng ; 11(2): 103-6, 1989 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-2704207

RESUMO

An automated microprocessor-based data acquisition and analysis system has been developed specifically to quantify electromyographic (EMG) activity induced by the convulsant agent catechol in the anaesthetized rat. The stimulus and EMG response are recorded on magnetic tape. On playback, the stimulus triggers a digital oscilloscope and, via interface circuitry, a BBC B microcomputer. The myoelectric activity is digitized by the oscilloscope before being transferred under computer control via a RS232 link to the microcomputer. This system overcomes the problems of dealing with signals of variable latency and allows quantification of latency, amplitude, area and frequency of occurrence of specific components within the signal. The captured data can be used to generate either signal or superimposed high resolution graphic reproductions of the original waveforms. Although this system has been designed for a specific application, it could easily be modified to allow analysis of any complex waveform.


Assuntos
Eletromiografia/métodos , Processamento de Sinais Assistido por Computador , Animais , Sistemas Computacionais , Desenho de Equipamento , Potenciais Evocados , Microcomputadores , Ratos , Design de Software
11.
Clin Chem ; 35(2): 238-40, 1989 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-2914367

RESUMO

This short-term study of the relative importance of estrogen and progesterone receptors shows that progesterone receptor correlates better than estrogen receptor with tumor recurrence regardless of lymph-node status. Life-table analysis has effectively identified only two groups of patients that may be classified by progesterone receptor status alone. Progesterone-receptor negativity correlated well with tumors of histological Grade III; estrogen-receptor positivity correlated with Grade I and II tumors. The earlier recurrence of Grade III breast tumors may explain why progesterone receptor is a better prognostic indicator than estrogen receptor in short-term studies.


Assuntos
Neoplasias da Mama/análise , Recidiva Local de Neoplasia/diagnóstico , Receptores de Estrogênio/análise , Receptores de Progesterona/análise , Neoplasias da Mama/patologia , Feminino , Seguimentos , Humanos , Menopausa , Prognóstico
12.
Eur J Pharmacol ; 145(2): 209-12, 1988 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-2895002

RESUMO

The effects of several excitatory amino acid receptor antagonists on sensory-evoked electromyographic activity induced by catechol have been studied in urethane-anaesthetised rats. 2-Amino-5-phosphono-valearic acid (1.2 mumol/kg i.c.), cis-2,3-piperidine dicarboxylic acid (1.4 mumol/kg i.c.), gamma-D-glutamyl-glycine (2.0 mumol/kg i.c.), 2-amino-7-phosphono-heptanoic acid (230 mumol/kg i.v.) and MK-801 (5 mg/kg i.p.) all significantly decreased the frequency of occurrence of those components of the sensory evoked EMG dependent on supraspinal structures, but were without effect on the spinal component.


Assuntos
Aminoácidos/fisiologia , Catecóis/farmacologia , Convulsões/induzido quimicamente , 2-Amino-5-fosfonovalerato , Aminoácidos/farmacologia , Animais , Dibenzocicloeptenos/farmacologia , Dipeptídeos/farmacologia , Maleato de Dizocilpina , Eletromiografia , Feminino , Ácidos Pipecólicos/farmacologia , Ratos , Receptores de Aminoácido , Receptores de Superfície Celular/efeitos dos fármacos , Valina/análogos & derivados , Valina/farmacologia
14.
Br J Pharmacol ; 88(2): 433-40, 1986 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-2873860

RESUMO

Synaptic transmission in the isolated olfactory cortex slice from the rat was monitored by recording the surface field potentials evoked on lateral olfactory tract (LOT) stimulation. Catechol (approximately 0.05 to 2 mM) caused a concentration-dependent, partially reversible increase in the amplitudes of all field potentials. In a series of conditioning experiments, catechol (1 mM) potentiated postsynaptic inhibition by a mechanism which was at least partially picrotoxin-insensitive. When the relationship between the stimulus input and evoked output was investigated in picrotoxin-treated slices, for a given tract action potential amplitude, catechol (0.25 and 0.5 mM) increased the amplitude of the field potential known as the N-wave; in contrast, for a given N-wave amplitude, the latency of the population spike was increased. Catechol (1 mM) increased the K+-evoked release of endogenous aspartate by a tetrodotoxin-insensitive mechanism whereas the release of glutamate and gamma-aminobutyric acid (GABA) was unaffected. Catechol (1 mM) had no effect on submaximal depolarizations evoked by L-aspartate, L-glutamate or GABA. It is concluded that catechol potentiates excitatory transmission at the LOT-superficial pyramidal cell synapse, possibly by increasing evoked transmitter release. Other synaptic actions of catechol may be consequent upon this increased excitatory input but the results do not exclude the possibility of separate and distinct actions on polysynaptic transmission.


Assuntos
Catecóis/farmacologia , Córtex Cerebral/efeitos dos fármacos , Bulbo Olfatório/efeitos dos fármacos , Potenciais de Ação/efeitos dos fármacos , Animais , Ácido Aspártico/metabolismo , Potenciais Evocados/efeitos dos fármacos , Glutamatos/metabolismo , Ácido Glutâmico , Técnicas In Vitro , Masculino , Fármacos Neuromusculares Despolarizantes , Potássio/farmacologia , Ratos , Ratos Endogâmicos , Ácido gama-Aminobutírico/metabolismo
15.
Br J Pharmacol ; 87(1): 167-73, 1986 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-3006851

RESUMO

The effects of certain anticonvulsant agents, namely, valproate, diazepam and phenobarbitone were investigated on catechol-induced spontaneous and evoked convulsions, in anaesthetized rats and mice. Valproate and diazepam significantly reduced the intensity of spontaneous convulsions and the frequency of occurrence of the longer-latency components (M2 and M3) of the evoked muscle response. Phenobarbitone significantly reduced spontaneous convulsions and the M3 component of the evoked muscle response. None of the drugs affected the short latency M1 component indicating a supra-spinal site of action of these drugs. Agents which modify gamma-aminobutyric acid (GABA)-mediated transmission were without effect on the frequency of occurrence of M1, M2 or M3. The results suggest that the convulsant action of catechol is not dependent on antagonism of GABA-mediated inhibition.


Assuntos
Carbacol/farmacologia , Convulsões/induzido quimicamente , Ácido gama-Aminobutírico/fisiologia , Animais , Diazepam/farmacologia , Feminino , Camundongos , Músculos/fisiologia , Fenobarbital/farmacologia , Picrotoxina/farmacologia , Receptores de GABA-A/efeitos dos fármacos , Ácido Valproico/farmacologia
16.
Tumour Biol ; 7(2-3): 99-104, 1986.
Artigo em Inglês | MEDLINE | ID: mdl-3797962

RESUMO

The value of 6-phosphogluconate dehydrogenase (6-PGDH) activity as a cytosolic marker of tumour cellularity has been assessed, together with its use as a prognostic indicator for primary breast cancer in 87 patients over 4 years. 6-PGDH activity shows a good correlation with histologically-assessed tumour cellularity in a sample of 114 patients (correlation coefficient = 0.83). Patients whose primary breast tumour had a high 6-PGDH activity showed poor relapse-free survival times when compared to those with low 6-PGDH activities (Log Rank chi 2 = 6.87, P less than 0.01). This compared with a Log Rank chi 2 of 2.22, P less than 0.20 for oestrogen positive and negative patients. These results suggest that 6-PGDH activity is a better prognostic indicator in primary breast cancer than oestrogen receptor status.


Assuntos
Neoplasias da Mama/enzimologia , Fosfogluconato Desidrogenase/análise , Neoplasias da Mama/patologia , Feminino , Humanos , Prognóstico , Receptores de Estrogênio/análise
17.
Br J Pharmacol ; 83(1): 83-8, 1984 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-6091830

RESUMO

Administration of catechol to rats anaesthetized with urethane produces a central excitatory state during which an EMG consisting of three temporally distinct components (M1, M2 and M3) can be recorded from forelimb and hindlimb muscles to electrical stimulation of cutaneous afferents. The probability of occurrence of all three components was measured in flexor and extensor muscles of fore- and hindlimb and showed that the long latency component (M3) occurred less frequently in hindlimb muscles than forelimb and that its probability of occurrence in hindlimb extensors was significantly reduced as compared to flexors. A possible reflex pathway for this long latency component of the EMG is suggested. Phenobarbitone (5 mg kg-1 i.v.) had no significant effect on the probability of occurrence of M1, M2 or M3. These results suggest that the long latency component (M3) is not due to activation of a spino-bulbo-spinal reflex as has been previously suggested. Cholinoceptor blocking drugs were found to reduce significantly the probability of occurrence of M2 and M3 and anticholinesterases to increase the probability of M2. None of the drugs was found to affect the short latency M1 component of the EMG. These results are discussed in relation to the possible reflex pathways of all three components of the EMG.


Assuntos
Catecóis/farmacologia , Músculos/efeitos dos fármacos , Anestesia , Animais , Inibidores da Colinesterase/farmacologia , Estimulação Elétrica , Eletromiografia , Potenciais Evocados/efeitos dos fármacos , Feminino , Membro Posterior/fisiologia , Músculos/inervação , Sistema Nervoso Parassimpático/efeitos dos fármacos , Fenobarbital/farmacologia , Ratos , Transmissão Sináptica/efeitos dos fármacos
19.
Acta Psychol (Amst) ; 48(1-3): 241-51, 1981 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7304231

RESUMO

Viewing a large-scale moving scene typically causes a free standing observer to lean in the direction of the seen motion. It was also noted that when the visual motion ceases, the observer drifts back toward the upright position, but instead of this body movement stopping at the vertical, it tends to continue so that the observer remains leaning in the opposite direction for several seconds before finally returning to the upright. The two experiments reported here were designed to investigate the determinants of this postural after-effect in relation to a pitch vection stimulus. Our findings clearly showed that the after-effect was dependent upon (1) the establishment of a prior visually-induced body lean, and (2) sight of the static display on the cessation of motion. The notion of an internalised representation of body position was invoked to account for these results.


Assuntos
Cinestesia , Orientação , Postura , Adulto , Discriminação Psicológica , Humanos , Masculino , Pessoa de Meia-Idade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA