Semantic priming in Alzheimer's dementia: Evidence for dissociation of automatic and attentional processes

The nature of the semantic memory deficit in dementia of the Alzheimer's type (DAT) was investigated in a semantic priming task which was designed to assess both automatic and attention-induced priming effects. Ten DAT patients and 10 age-matched control subjects completed a word naming semantic priming task in which both relatedness proportion (RP) and stimulus-onset asynchrony (SOA) were varied. A clear dissociation between automatic and attentional priming effects in both groups was demonstrated; however, the DAT subjects pattern of priming deviated significantly from that of the normal controls. The DAT patients failed to produce any priming under conditions which encouraged automatic semantic processing and produced facilitation only when the RP was high. In addition, the DAT group produced hyperpriming, with significantly larger facilitation effects than the control group. These results suggest an impairment of automatic spreading activation in DAT and have implications for theories of semantic memory impairment in DAT as well as models of normal priming. (C) 2001 Academic Press.

Effectiveness of brown planthopper predators: Population suppression by two species of spider, Pardosa pseudoannulata (Araneae, Lycosidae) and Araneus inustus (Araneae, Araneidae)

The most abundant natural enemies found in Cambodian rice field are spiders, mostly Araneus inustus and Pardosa pseudoannulata. These two hunting and wolf spider, respectively, are believed to actively contribute to brown planthopper (BPH) population control. However, how much each species attacks prey in Cambodian field condition is unknown. We conducted field experiments in Cambodia during the wet season at two locations, a famner's fields at Takeo and at CARDI, using both field cages and natural conditions. Cages were sprayed with insecticide to remove all pre-existing insects in the cages and then washed after 10 days to reduce insecticide residue. Results confirmed BPH inside the cage were killed by the insecticide. A known BPH population was reared inside the cages starting with 3 pairs of adults. Temporary cages were removed after counting second instar BPH and permanent cages were left in place. Spiders were released into the cages for 15 days. In permanent cages either two individual A. inustus or P. pseudoannulata were allowed to feed on BPH prey. Both spider species have the same killing ability in dense prey populations, but predation is higher for Pardosa at low prey density. In uncaged field environments (where more than just BPH prey are available) with a spider/BPH ratio 1:3 to 1:11 BPH mortality was 78–91%. Within 15 days in permanent cages spiders caused 100% BPH mortality at an average predator/prey ratio of 1:5 to 1:14. At a ratio of 1:18 or higher there was some BPH survival in cages.

Establishment of Nilaparvata Iugens Stl in rice crop nurseries: a possible source of outbreaks

We tested the hypothesis that early-planted seedbeds of rioe are mere heavily infested with brown planthopper (BPH) than later seedbeds, and that transplanted plants with lBPH are a source of subsequent population increase and possible outbreaks. The experiments were conducted at CARDI and Takeo province in wet season 2000 and early wet 2 season 200 I. BPH at O. 25. 50, 100, 200 1m were infested onto plants with low and high fertilizer treatments. Rice seeds of varieties moderately and highly susceptible to BPH were sown 3 weeks early, 2 weeks early, at the normal time, and later than normal (5 weeks) and treated with low and high fertilizer rates. At Takeo, the 3< weeks early seedbeds were infested by BPH migration, and both varieties with high fertilizer caught more immigrant insects and subsequently had damaging outbreaks of BPH in the third generation. At CARDl, no seedbeds were infested with immigrant BPH. Seedbeds in areas with continuous cropping of rice have a high risk of BPH attack, Seedlings infested with 200, 100, and 50 BPI[/m2 resulted in death of the plant. Plants with 100 and 200 BPH/m'! were kj[Jed sooner. With 25 BPIVm2 plants were not kllled, but subsequent population increase caused yi eld reduction. Yield loss was high ill higlh fertilizer treated plants. Key words , ,

Detection of West Nile virus antigen in mosquitoes and avian tissues by a monoclonal antibody-based capture enzyme immunoassay

An antigen capture immunoassay to detect West Nile (WN) virus antigen in infected mosquitoes and avian tissues has been developed. With this assay purified WN virus was detected at a concentration of 32 pg/0.1 ml, and antigen in infected suckling mouse brain and laboratory-infected mosquito pools could be detected when the WN virus titer was 10(2.1) to 10(3.7) PFU/0.1 ml. In a blindly coded set of field-collected mosquito pools (n = 100), this assay detected WN virus antigen in 12 of 18 (66.7%) TaqMan-positive pools, whereas traditional reverse transcriptase PCR detected 10 of 18 (55.5%) positive pools. A sample set of 73 organ homogenates from naturally infected American crows was also examined by WN virus antigen capture immunoassay and TaqMan for the presence of WN virus. The antigen capture assay detected antigen in 30 of 34 (88.2%) TaqMan-positive tissues. Based upon a TaqMan-generated standard curve of infectious WN virus, the limit of detection in the antigen capture assay for avian tissue homogenates was approximately 10(3) PFU/0.1 ml. The recommended WN virus antigen capture protocol, which includes a capture assay followed by a confirmatory inhibition assay used to retest presumptive positive samples, could distinguish between the closely related WN and St. Louis encephalitis viruses in virus-infected mosquito pools and avian tissues. Therefore, this immunoassay demonstrates adequate sensitivity and specificity for surveillance of WN virus activity in mosquito vectors and avian hosts, and, in addition, it is easy to perform and relatively inexpensive compared with the TaqMan assay.

Pragmatic solidarism and the dilemmas of humanitarian intervention

The theory and practice of humanitarian intervention in the 1990s has produced a series of seemingly intractable dilemmas. Why do states act in some cases and not others? How are we to evaluate the legitimacy of particular acts? This article introduces a new perspective on these questions informed by a combination of pragmatism and solidarism. It argues that although the search for criteria that may be used to judge the legitimacy and efficacy of humanitarian intervention may be a futile one, it is possible to think about a politics of legitimate humanitarian intervention. Such a politics may be based on three key insights drawn from pragmatism: the dialogic construction of moral knowledge, the fallibility of knowledge, and the priority of democracy over philosophy. The article discusses how such a pragmatic solidarism may be used to interrogate the quest for legitimising criteria and to build a new politics of humanitarian intervention.

Distribution of Chlamydia pneumoniae DNA in atherosclerotic carotid arteries: significance for sampling procedures

Despite extensive efforts to confirm a direct association between Chlamydia pneumoniae and atherosclerosis, different laboratories continue to report a large variability in detection rates. In this study, we analyzed multiple sections from atherosclerotic carotid arteries from 10 endartectomy patients to determine the location of C. pneumoniae DNA and the number of sections of the plaque required for analysis to obtain a 95% confidence of detecting the bacterium. A sensitive nested PCR assay detected C. pneumoniae DNA in all patients at one or more locations within the plaque. On average, 42% (ranging from 5 to 91%) of the sections from any single patient had C. pneumoniae DNA present. A patchy distribution of C. pneumoniae in the atherosclerotic lesions was observed, with no area of the carotid having significantly more C. pneumoniae DNA present. If a single random 30-mum-thick section was tested, there was only a 35.6 to 41.6% (95% confidence interval) chance of detecting C. pneumoniae DNA in a patient with carotid artery disease. A minimum of 15 sections would therefore be required to obtain a 95% chance of detecting all true positives. The low concentration and patchy distribution of C. pneumoniae DNA in atherosclerotic plaque appear to be among the reasons for inconsistency between laboratories in the results reported.

Um exercício de desconstrução do conceito e da prática de segmentação de mercado inspirado em Woody Allen

O conceito de segmentação de mercado constitui-se em uma forte ferramenta freqüentemente utilizada na tomada de decisão nas organizações. Neste artigo, busca-se analisar elementos nem sempre privilegiados quando se trata a segmentação de mercado como discurso hegemônico. A crítica aqui apresentada inspira-se no filme Desconstruindo Harry, de Woody Allen, o que permitirá compreender o exercício de desconstrução do conceito e da prática da segmentação de mercado com base no gênero e na etnia. Essa proposta ampara-se sobre o postulado de Derrida (1999) de que qualquer conceito, palavra ou significado léxico é passível de desconstrução e na hipótese de que o conceito de segmentação de mercado e sua prática encerram significados não revelados, guardando em si um conjunto de atores e vozes marginalizados.

Avaliação do risco da arrecadação federal por meio de macrocarteiras de tributos

Este artigo emprega o modelo média-variância de Harry Markowitz na formação de macrocarteiras de tributos com participações ótimas de agregados tributários na arrecadação federal. Essas macrocarteiras ótimas, ou macrocarteiras eficientes, são aquelas que produzem a menor instabilidade do crescimento da arrecadação para uma determinada taxa de crescimento esperada, ou uma maior taxa de crescimento esperada para uma determinada instabilidade aceitável da arrecadação. Avaliamos o efeito das participações ótimas propostas pelo nosso modelo para a arrecadação das receitas de um conjunto de agregados tributários e comparamos seu perfil de crescimento com os resultados obtidos pelo governo federal. Nossos resultados experimentais mostraram que, no contexto analisado, a estrutura tributária da arrecadação federal opera em um nível subótimo de instabilidade-crescimento. Através da diversificação eficiente das receitas dos agregados tributários foi possível obter, no perfil conservador, um crescimento acumulado de arrecadação 28 pontos percentuais acima do crescimento acumulado realizado dos mesmos agregados tributários e com apenas 25% da sua instabilidade - um risco quatro vezes menor. No perfil moderado, foi alcançado um crescimento acumulado 33 pontos percentuais acima, para o mesmo nível de instabilidade.

Ocorrência de silicose entre trabalhadores da indústria cerâmica da cidade de Jundiaí, SP (Brasil)

Tomando-se como ponto de partida a descoberta de um caso de silicose entre trabalhadores da indústria cerâmica, que tradicionalmente era considerada como pouco importante na gênese dessa pneumoconiose, foi possível, através de exame radiológico, evidenciar que uma proporção muito elevada dos trabalhadores desse tipo de indústria é portadora de alterações radiológicas características da silicose. Descrevem-se os achados radiológicos, que na sua maioria foram de opacidades regulares de pequeno tamanho. Com base nesse trabalho foi possível fazer-se a descoberta de outros "focos" de silicose em outras áreas do Estado de São Paulo.