In-Situ Cleaning of Metal Photo-Cathodes in rf Guns

Metal cathodes installed in rf guns typically exhibit much lower quantum efficiency than the theoretical limit. Experimenters often use some sort of in situ technique to ''clean'' the cathode to improve the QE. The most common technique is laser cleaning where the laser is focused to a small spot and scanned across the cathode surface. However, since the laser is operated near the damage threshold, it can also damage the cathode and increase the dark current. The QE also degrades over days and must be cleaned regularly. We are searching for a more robust cleaning technique that cleans the entire cathode surface simultaneously. In this paper we describe initial results using multiple techniques such as several keV ion beams, glow discharge cleaning and back bombarding electrons. Results are quantified in terms of the change in QE and dark current

Buffalo, Bush Meat, and the Zoonotic Threat of Brucellosis in Botswana

Brucellosis is a zoonotic disease of global importance infecting humans, domestic animals, and wildlife. Little is known about the epidemiology and persistence of brucellosis in wildlife in Southern Africa, particularly in Botswana.Archived wildlife samples from Botswana (1995-2000) were screened with the Rose Bengal Test (RBT) and fluorescence polarization assay (FPA) and included the African buffalo (247), bushbuck (1), eland (5), elephant (25), gemsbok (1), giraffe (9), hartebeest (12), impala (171), kudu (27), red lechwe (10), reedbuck (1), rhino (2), springbok (5), steenbok (2), warthog (24), waterbuck (1), wildebeest (33), honey badger (1), lion (43), and zebra (21). Human case data were extracted from government annual health reports (1974-2006).Only buffalo (6%, 95% CI 3.04%-8.96%) and giraffe (11%, 95% CI 0-38.43%) were confirmed seropositive on both tests. Seropositive buffalo were widely distributed across the buffalo range where cattle density was low. Human infections were reported in low numbers with most infections (46%) occurring in children (<14 years old) and no cases were reported among people working in the agricultural sector.Low seroprevalence of brucellosis in Botswana buffalo in a previous study in 1974 and again in this survey suggests an endemic status of the disease in this species. Buffalo, a preferred source of bush meat, is utilized both legally and illegally in Botswana. Household meat processing practices can provide widespread pathogen exposure risk to family members and the community, identifying an important source of zoonotic pathogen transmission potential. Although brucellosis may be controlled in livestock populations, public health officials need to be alert to the possibility of human infections arising from the use of bush meat. This study illustrates the need for a unified approach in infectious disease research that includes consideration of both domestic and wildlife sources of infection in determining public health risks from zoonotic disease invasions

Factors affecting speech perception in children cochlear 22-channel cochlear prosthesis [Abstract]

Since the implantation of the first children with the Nucleus 22-channel cochlear prosthesis in Melbourne in 1985, there have been rapid expansion world-wide in the number of children using this implant system. Longer-term experience with implanted children has led to improvements in paediatric assessment and management. Speech processing strategies have also been improved, resulting in a series of increases in speech perception benefits.3-5 Apri

Campaña Oceanográfica LATITUD-I : 5 de marzo - 15 de abril de 1995 : BIO Hespérides

Se ha realizado en el tránsito de vuelta de la Antártida del BIO-Hespérides, desde el 5 de marzo en Punta Arenas hasta el 15 de abril en Santa Cruz de TenerifeEl objetivo fundamental del proyecto es comprobar la hipótesis de que los balances metabólico y de fotones de la capa fótica del océano varían sistemáticamente con la latitud. [...]Proyecto financiado por la CICYT con el nº de referencia AMB94-0739Peer reviewe

Adesão e não-adesão ao tratamento farmacológico para depressão

O presente estudo objetivou compreender aspectos relacionados à adesão e a não-adesão ao tratamento farmacológico para depressão, envolvendo usuários e ex-usuários de um serviço público de saúde mental. Foram entrevistados, individualmente, 24 pacientes (12 aderentes e 12 não aderentes ao tratamento medicamentoso para depressão). Por meio da análise de conteúdo das entrevistas, identificou-se que o fenômeno da adesão/não-adesão estaria inter-relacionado a aspectos intrapessoais, interpessoais e ao contexto do tratamento do paciente. Os resultados fomentaram reflexões acerca do papel de equipes de saúde mental no incremento da adesão ao tratamento, bem como da necessidade de uma maior consideração do indivíduo, da família e do atendimento prestado pela instituição