Performance and materials aspects of Ge:Be photoconductors

Ge:Be photoconductors were developed for low photon background applications in the 30 to 50 MM wavelength region. These detectors provide higher responsivity and lower noise equivalent power (NEP) than the Ge:Ga detectors currently operating in this wavelength range. Beryllium doped single crystals were grown by the Czochralski method from a carbon susceptor under a vacuum of approx. one million torr. An optimum detective quantum efficiency of 46% at a background flux of 1.5 x 10 to the 8th power photons/second (7 x 10 to the 13th power W) was reported. Ge:Be detector performance is strongly influenced by the absolute concentrations and the concentration ratio of residual shallow donors and shallow acceptors

The coronavirus outbreak: the central role of primary care in emergency preparedness and response

On the last day of 2019, a cluster of cases of a pneumonia with unknown cause were reported by the Chinese authorities to the World Health Organization (WHO), believed to be connected to a seafood market in Wuhan, China. This market was closed the following day. On 7 January 2020, a novel coronavirus was isolated, and known pathogens were ruled out.1 Coronaviruses usually cause respiratory illness ranging from the common cold to severe acute respiratory syndrome (SARS). Clinical symptoms and signs of the Wuhan coronavirus include fever, with some sufferers experiencing difficulty breathing and bilateral pulmonary infiltrates seen on chest X-ray. WHO are referring to it as ‘2019-nCov’. At the time of writing, there have been over 4,500 confirmed cases and 106 deaths, including among healthcare workers. Over 98% of these cases are within mainland China, but cases have also been confirmed in tens of other countries

Observation of large-scale multi-agent based simulations

The computational cost of large-scale multi-agent based simulations (MABS) can be extremely important, especially if simulations have to be monitored for validation purposes. In this paper, two methods, based on self-observation and statistical survey theory, are introduced in order to optimize the computation of observations in MABS. An empirical comparison of the computational cost of these methods is performed on a toy problem

Sex-Differences in Lung Cancer Cell-Types? An Epidemiologic Study in Ireland

Objective: This study assesses the epidemiological pattern of lung cancer cell-types in Ireland, with identification of any underlying gender variations. Methods: Lung cancer incidence data, including the major cell-types: squamous-cell-carcinoma (SCC), adenocarcinoma (AC), small-cell-lung-carcinoma (SCLC) and large-cell-carcinoma (LCC) were obtained from the national cancer registry (1994–2000), together with individual characteristics, such as age, gender, smoking status, and the year of diagnosis. Age-standardised incidence rates (ASIR), male-to-female (M: F) rate ratios (RR) of ASIR for SCC and AC, as well as RR of AC: SCC according to smoking status for both sexes, were estimated. Estimated-annual-percent-changes for each of the cell-types were calculated. Results: AC incidence in females is rising annually (8.5%, p=0.008) from 1994 to 2000, while SCC is declining (−5.4%, p=0.01) in males. M: F ratios of ASIR are consistently greater than ‘one’, but converging recently. RR of AC: SCC is also approaching ‘unity’ across both sexes, irrespective of the smoking status. Conclusions: An apparent increase in lung AC incidence in females was observed in Ireland that might indicate some local environmental risk factors, in addition to changing smoking habits. The study findings do not support the hypothesis that females in general are at higher risk for lung cancer development, but tobacco and histologic-specific susceptibility cannot be ruled out

Comprehension as social and intellectual practice: Rebuilding curriculum in low socioeconomic and cultural minority schools

This article reframes the concept of comprehension as a social and intellectual practice. It reviews current approaches to reading instruction for linguistically and culturally diverse and low socioeconomic students, noting an emphasis on comprehension as autonomous skills. The Four Resources model (Freebody & Luke, 1990) is used to make the case for the integration of comprehension instruction with an emphasis on student cultural and community knowledge, and substantive intellectual and sociocultural content in elementary school curricula. Illustrations are drawn from research underway on the teaching of literacy in primary schools in low SES communities