Investigation of gamma-ray sensitivity of neutron detectors based on thin converter films

Currently, many detector technologies for thermal neutron detection are in development in order to lower the demand for the rare 3He gas. Gas detectors with solid thin film neutron converters readout by gas proportional counter method have been proposed as an appropriate choice for applications where large area coverage is necessary. In this paper, we investigate the probability for gamma-rays to generate a false count in a neutron measurement. Simulated results are compared to measurement with a 10B thin film prototype and a 3He detector. It is demonstrated that equal gamma-ray rejection to that of 3He tubes is achieved with the new technology. The arguments and results presented here are also applicable to gas detectors with converters other than solid 10B layers, such as 6Li layers and 10BF3 gas.Comment: Submitted to Journal of Instrumentatio

The relevance of non-human primate and rodent malaria models for humans

At the 2010 Keystone Symposium on "Malaria: new approaches to understanding Host-Parasite interactions", an extra scientific session to discuss animal models in malaria research was convened at the request of participants. This was prompted by the concern of investigators that skepticism in the malaria community about the use and relevance of animal models, particularly rodent models of severe malaria, has impacted on funding decisions and publication of research using animal models. Several speakers took the opportunity to demonstrate the similarities between findings in rodent models and human severe disease, as well as points of difference. The variety of malaria presentations in the different experimental models parallels the wide diversity of human malaria disease and, therefore, might be viewed as a strength. Many of the key features of human malaria can be replicated in a variety of nonhuman primate models, which are very under-utilized. The importance of animal models in the discovery of new anti-malarial drugs was emphasized. The major conclusions of the session were that experimental and human studies should be more closely linked so that they inform each other, and that there should be wider access to relevant clinical material

Characteristics of specialists treating hypothyroid patients:the “THESIS” collaborative

Introduction: Thyroid specialists influence how hypothyroid patients are treated, including patients managed in primary care. Given that physician characteristics influence patient care, this study aimed to explore thyroid specialist profiles and associations with geo-economic factors. Methods: Thyroid specialists from 28 countries were invited to respond to a questionnaire, Treatment of Hypothyroidism in Europe by Specialists: an International Survey (THESIS). Geographic regions were defined according to the United Nations Statistics Division. The national economic status was estimated using World Bank data on the gross national income per capita (GNI per capita). Results: 5,695 valid responses were received (response rate 33·0%). The mean age was 49 years, and 65·0% were female. The proportion of female respondents was lowest in Northern (45·6%) and highest in Eastern Europe (77·2%) (p &lt;0·001). Respondent work volume, university affiliation and private practice differed significantly between countries (p&lt;0·001). Age and GNI per capita were correlated inversely with the proportion of female respondents (p&lt;0·01). GNI per capita was inversely related to the proportion of respondents working exclusively in private practice (p&lt;0·011) and the proportion of respondents who treated &gt;100 patients annually (p&lt;0·01). Discussion: THESIS has demonstrated differences in characteristics of thyroid specialists at national and regional levels, strongly associated with GNI per capita. Hypothyroid patients in middle-income countries are more likely to encounter female thyroid specialists working in private practice, with a high workload, compared to high-income countries. Whether these differences influence the quality of care and patient satisfaction is unknown, but merits further study.</p

Les réévaluations du mark dans la conjoncture allemande

[spa] Las dos fases de expansión de 1959-1960 y 1968-1969 en la R.F.A. presentan gran núméro de analogfas : pleno empleo de la capacidad de producción, tasa baja del paro laboral, crecimiento rápido de la producción y de los pedidos; pero, al mismo tiempo, mantenimiento de excedentes comerciales considerables. . Las diferencias provienen, en particular, de las « situaciones de partida » (disminución de la actividad sin aumentación del paro laboral en 1958, recesión y subempleo en 1967) y del ambiente financiero internacional. . La modificación de paridad de 1961 no causó finalmente más que efectos limitados : en el plan interior, el ritmo de aumento de los precios no se aflojó sensiblemente, y la tasa de crecimiento del P.N.B. (Producto Nacional Bruto) siguiô sostenida. En el plan . exterior, la moderación de las exportaciones no tuvo por consecuencia la reducción del saldo comercial por haber fuerte- mente disminuido el ritmo de progresión de las importaciones. Es verdad que, en 1962, debia de manifestarse una notable — pero muy provisional — disminución del excedente comercial. Si se examina la situación actual, puede temerse también que la reciente revaluación del DM tenga solo pocos efectos sobre el equilibrio interior y exterior de la R.F.A. . Finalmente, cierta imagen del « milagro » alemân (expansion rápida y equilibrada) deberâ de ser, sin duda, un poco revisada : en particular, la reducción prévisible de la población activa en los an os que vienen modificará profundamente las condiciones de realizacion del equilibrio económico en la República Federal. . La cuestión del marco, enmascarada durante algún tiempo por la revaluación, amenaza de rea- parecer con la misma agudeza, si los problemas que plantean la armonizacién de las polfticas coyunturales y la convergencia de los objectivos a medio plazo no son resueltos a tiempo. [eng] There are a great many similarities between the two periods of expansion in the Federal Republic of Germany, 1959-1960 and 1968-1969; full utilisation of production capacities, low unemployment rates, rapid growth of production and orders, but at the same time, the maintenance of considerable trade surpluses. . The main differences are in the « starting points » (slowdown without increased unemployment in 1958, recession and under-employment in 1967) and in the international financial environment. . The modification of parity in 1961 finally had only limited effects; internally, the pace of price increases did not appreciably slow down and the growth rate of the GNP was sustained. Externally, the moderation of exports did not involve any reduction in the trade balance, the rate of progression of imports having fallen considerably. It is true that in 1962 there was to be a substantial — but very temporary — decline in the trade surplus. . Looking at the present situation, it may also be feared that the recent revaluation of the Deutsch- mark may have little effect on the internal and external equilibrium of the Federal Republic. . In the last analysis, a certain image of the German « miracle » (rapid and balanced growth) may have to be somewhat revised; in particular, the foreseeable reduction in the work force in future years will radically change the conditions for the achievement of the economic equilibrium of the Federal Republic. . The question of the Mark, dissimulated for a time by revaluation, is likely to arise again with the same acuteness, if the problems of harmonising cyclical policies and of the convergence of medium term aims are not solved in good time. [fre] Les deux phases d'expansion de 1959-1960 et 1968-1969 en R.F.A. présentent un grand nombre d'analogies : plein emploi des capacités de production, faible taux de chômage, croissance rapide de la production et des commandes; mais, en même temps, maintien d'excédents commerciaux considérables. . Les différences tiennent notamment aux « situations de départ » (ralentissement sans augmentation du chômage en 1958, récession et sous-emploi en 1967) et à l'environnement financier international. . La modification de parité de 1961 n'a finalement exercé que des effets limités; sur le plan intérieur, le rythme d'augmentation des prix ne s'est pas sensiblement ralenti, et le taux de croissance du P.N.B. est resté soutenu. Sur le plan extérieur, la modération des exportations n'a pas entraîné de réduction du solde commercial, le rythme de progression des importations ayant fortement diminué. Il est vrai qu'en 1962 on devait assister à un fléchissement notable — mais très provisoire — de l'excédent commercial. . Si l'on examine la situation actuelle, on peut craindre également que la réévaluation récente du DM n'ait que peu d'effets sur l'équilibre intérieur et extérieur de la R.F.A. . En définitive, une certaine image du « miracle » allemand (expansion rapide et équilibrée) devra sans doute être quelque peu révisée : en particulier, la réduction prévisible de la population active dans les années à venir modifiera profondément les conditions de réalisation de l'équilibre économique de la République fédérale. . La question du mark, masquée pour quelque temps par la réévaluation, risque de ressurgir avec la même acuité, si les problèmes d'harmonisation des politiques conjoncturelles et de convergence des objectifs à moyen terme ne trouvent pas, en temps voulu, leur solution.