Simulation of the load-unload response ratio and critical sensitivity in the lattice solid model

The Load-Unload Response Ratio (LURR) method is an intermediate-term earthquake prediction approach that has shown considerable promise. It involves calculating the ratio of a specified energy release measure during loading and unloading where loading and unloading periods are determined from the earth tide induced perturbations in the Coulomb Failure Stress on optimally oriented faults. In the lead-up to large earthquakes, high LURR values are frequently observed a few months or years prior to the event. These signals may have a similar origin to the observed accelerating seismic moment release (AMR) prior to many large earthquakes or may be due to critical sensitivity of the crust when a large earthquake is imminent. As a first step towards studying the underlying physical mechanism for the LURR observations, numerical studies are conducted using the particle based lattice solid model (LSM) to determine whether LURR observations can be reproduced. The model is initialized as a heterogeneous 2-D block made up of random-sized particles bonded by elastic-brittle links. The system is subjected to uniaxial compression from rigid driving plates on the upper and lower edges of the model. Experiments are conducted using both strain and stress control to load the plates. A sinusoidal stress perturbation is added to the gradual compressional loading to simulate loading and unloading cycles and LURR is calculated. The results reproduce signals similar to those observed in earthquake prediction practice with a high LURR value followed by a sudden drop prior to macroscopic failure of the sample. The results suggest that LURR provides a good predictor for catastrophic failure in elastic-brittle systems and motivate further research to study the underlying physical mechanisms and statistical properties of high LURR values. The results provide encouragement for earthquake prediction research and the use of advanced simulation models to probe the physics of earthquakes.

Biological determinants of extinction risk: why are smaller species less vulnerable?

It is becoming increasingly clear that species of smaller body size tend to be less vulnerable to contemporary extinction threats than larger species, but few studies have examined the mechanisms underlying this pattern. In this paper, data for the Australian terrestrial mammal fauna are used to ask whether higher reproductive output or smaller home ranges can explain the reduced extinction risk of smaller species. Extinct and endangered species do indeed have smaller litters and larger home ranges for their body size than expected under a null model. In multiple regressions, however, only litter size is a significant predictor of extinction risk once body size and phylogeny are controlled for. Larger litters contribute to fast population growth, and are probably part of the reason that smaller species are less extinction-prone. The effect of litter size varies between the mesic coastal regions and the and interior of Australia, indicating that the environment a species inhabits mediates the effect of biology on extinction risk. These results suggest that predicting extinction risk from biological traits is likely to be a complex task which must consider explicitly interactions between biology and environment.

Enhanced vector competence of Aedes aegypti (Diptera : Culicidae) from the torres strait compared with mainland Australia for dengue 2 and 4 viruses

Australian Aedes aegypti (L.) mosquitoes colonized from the Torres Strait and three mainland localities (Charters Towers, Townsville, and Cairns) were fed on blood suspensions containing dengue virus type 2 (DEN-2) or dengue virus type 4 (DEN-4). Variation was found in oral susceptibility to DEN-2 (59-99% infection) and DEN-4 (28-79% infection) among Ae. aegypti assayed for virus at 8, 12, 16, or 20 d after ingestion of infected blood. Torres Strait Ae. aegypti were the most susceptible to DEN-2 and were significantly more efficient in transmission to capillary tube at 16 d (76% transmission) than mainland Ae. aegypti populations (20-28% transmission). Torres Strait Ae. aegypti were also the most susceptible to DEN-4, although transmission did not vary significantly from mainland populations at 16 d (12% compared with 0-4%) or 20 d (16% compared with 4-16%). Disseminated infection (i.e., leg infection) with either DEN-2 or DEN-4 was not an accurate predictor of transmission potential. This study demonstrates differences among Australian Ae. aegypti populations in vector competence for DEN-2 and DEN-4. Torres Strait Ae. aegypti were more frequently infected and able to transmit DEN-2 at higher rates than mainland populations. These data indicate that the Torres Strait region is potentially more receptive to dengue transmission than mainland localities, a finding discussed with respect to past outbreaks.

Independent contribution of plaque complexity to myocardial ischemia during Dobutamine stress echocardiography

The influence of complex plaque morphology on the extent of demand-induced ischemia in unselected patients is not well defined. We sought to investigate the functional significance of lesion morphology in patients who underwent coronary angiography and dobutamine stress echocardiography (DSE).,Angiography and DSE were performed within a 6-month period (mean 1 +/- 1 month) in 196 patients. Angiographic assessments involved quantification of stenosis severity, assessment of the extent of jeopardized myocardium, and categorization of plaque morphology according to the Ambrose classification. DSE was interpreted by separate investigators with respect to wall motion score index (WMSI) and number of coronary territories involved. A general linear model was constructed to assess,the independent contribution of patient characteristics and angiographic and DSE results with respect to extent of ischemic myocardium. Complex lesion morphology was seen in 62 patients (32%). Patients with complex lesions were more likely to have had prior myocardial infarction (p < 0.001) and be current smokers (p = 0.03). During angiography, they exhibited a trend toward a greater number of diseased vessels, had a greater coronary jeopardy score (p < 0.001) and more frequent collateral flow (p = 0.03). During echocardiography, patients had a higher stress WMSI (p < 0.001) and were more likely to show ischemia in all 3 arterial territories (p < 0.01). On multivariate regression, the coronary artery jeopardy score and the presence of complex plaque morphology were independent predictors of the extent of ischemic myocardium (R 2 = 34%, p < 0.001). Thus, patients with complex plaque morphology are older, more likely to smoke, and more likely to have had prior myocardial. infarction. They exhibit more extensive disease with higher coronary jeopardy scores and a higher resting and peak stress WMSI. Despite these differences, complex plaque morphology remains an independent predictor of the extent of ischemia during stress. (C) 2003 by Excerpta Medica, Inc.

Transdermal penetration of vasoconstrictors - Present understanding and assessment of the human epidermal flux and retention of free bases and ion-pairs

Purpose. As reductions in dermal clearance increase the residence time of solutes in the skin and underlying tissues we compared the topical penetration of potentially useful vasoconstrictors (VCs) through human epidermis as both free bases and ion-pairs with salicylic acid (SA). Methods. We determined the in vitro epidermal flux of ephedrine, naphazoline, oxymetazoline, phenylephrine, and xylometazoline applied as saturated solutions in propylene glycol: water (1: 1) and of ephedrine, naphazoline and tetrahydrozoline as 10% solutions of 1: 1 molar ratio ion-pairs with SA in liquid paraffin. Results. As free bases, ephedrine had the highest maximal flux, Jmax = 77.4 +/- 11.7 mug/cm(2)/h, being 4-fold higher than tetrahydrozoline and xylometazoline, 6-fold higher than phenylephrine, 10-fold higher than naphazoline and 100-fold higher than oxymetazoline. Stepwise regression of solute physicochemical properties identified melting point as the most significant predictor of flux. As ion-pairs with SA, ephedrine and naphazoline had similar fluxes (11.5 +/- 2.3 and 12.0 +/- 1.6 mug/cm(2)/h respectively), whereas tetrahydrozoline was approximately 3-fold slower. Corresponding fluxes of SA from the ion-pairs were 18.6 +/- 0.6, 7.8 +/- 0.8 and 1.1 +/- 0.1 respectively. Transdermal transport of VC's is discussed. Conclusions. Epidermal retention of VCs and SA did not correspond to their molar ratio on application and confirmed that following partitioning into the stratum corneum, ion-pairs separate and further penetration is governed by individual solute characteristics.

Poor correlation of mid-femoral measurements by CT and hip measurements by DXA in the elderly

Background and aims: Hip fracture is a devastating event in terms of outcome in the elderly, and the best predictor of hip fracture risk is hip bone density, usually measured by dual X-ray absorptiometry (DXA). However, bone density can also be ascertained from computerized tomography (CT) scans, and mid-thigh scans are frequently employed to assess the muscle and fat composition of the lower limb. Therefore, we examined if it was possible to predict hip bone density using mid-femoral bone density. Methods: Subjects were 803 ambulatory white and black women and men, aged 70-79 years, participating in the Health, Aging and Body Composition (Health ABC) Study. Bone mineral content (BMC, g) and volumetric bone mineral density (vBMD, mg/cm(3)) of the mid-femur were obtained by CT, whereas BMC and areal bone mineral density (aBMD, g/cm(2)) of the hip (femoral neck and trochanter) were derived from DXA. Results: In regression analyses stratified by race and sex, the coefficient of determination was low with mid-femoral BMC, explaining 6-27% of the variance in hip BMC, with a standard error of estimate (SEE) ranging from 16 to 22% of the mean. For mid-femur vBMD, the variance explained in hip aBMD was 2-17% with a SEE ranging from 15 to 18%. Adjusting aBMD to approximate volumetric density did not improve the relationships. In addition, the utility of fracture prediction was examined. Forty-eight subjects had one or more fractures (various sites) during a mean follow-up of 4.07 years. In logistic regression analysis, there was no association between mid-femoral vBMD and fracture (all fractures), whereas a 1 SD increase in hip BMD was associated with reduced odds for fracture of similar to60%. Conclusions: These results do not support the use of CT-derived mid-femoral vBMD or BMC to predict DXA-measured hip bone mineral status, irrespective of race or sex in older adults. Further, in contrast to femoral neck and trochanter BMD, mid-femur vBMD was not able to predict fracture (all fractures). (C) 2003, Editrice Kurtis.

Injury related risk behavior - a study of Australian skydivers

Risk taking behaviour has been identified as an important host-related determinant of injury in young adults. The aim of this study is to clarify the relationship between the two key elements of risk taking behaviour - ie, risk assessment and risk acceptance - in participants of a high risk sporting activity. Skydivers registered with the Australian Parachute Federation were sampled at several jump meetings held at three 'drop-zones' in North Eastern Australia. A cross sectional survey of 215 skydivers ascertained each subject's risk assessment of each of nine hypothetical sky diving scenes and whether or not they would jump in the described conditions. Variables which independently predicted an individual's risk assessment were age group (p < 0.05), gender (p < 0.05) and scene details (p < 0.001). Risk assessment was found to be a statistically significant predictor of the decision to jump, with a 22% decrease in the odds of jumping with every unit increase in risk assessment (OR = 0.78: 95% Cl; 0.76, 0.80). Gender was also found to be a statistically significant predictor of the decision to jump, with males being 19% more likely to jump than females, after controlling for age, experience, currency and risk assessment (OR = 1.19: 95% CI; 1.04, 1.38). The importance of these results is that, by quantifying the relationship between two key elements of risk taking behaviour and several important host factor determinants, they facilitate more informed discussion about the possible role of risk taking behaviour in the causation of injury.

Loneliness in Middle and Old Age

Purpose of the research: (a) To identify the degree of much loneliness reported in the Portuguese population over 50 years of age and (b) test whether loneliness can be predicted by socio-demographic, health related or social characteristic of the sample other than age. Materials and methods: 1174 late middle age and older adults were interviewed face to face by different interviewers across the country; after the informed consent was signed, we asked the participants several socio-demographic and health-related questions; finally we asked ‘‘How often do you feel lonely?’’ and participants responded according to a five point Likert scale. Principal results: The results showed that 12% of participants reporting feeling lonely often or always, whereas 40% reporting never feeling lonely. The remaining 48% self-reported they felt lonely seldom or sometimes. Additionally, results show that, when taken together, variables such as marital status, type of housing, residence settings, health conditions, social satisfaction, social isolation, lack of interest, transportation, and age were predictors of loneliness. Major conclusions: (1) The association of loneliness with advanced age has been greatly exaggerated by mass media and common sense; (2) But although our findings did not confirm the most alarmist views, the 12% of older adults reporting that they are feeling lonely always or often should be cause for attention and concern. It is necessary to understand the meaning, reasons and level of suffering implied on those feelings of loneliness. (3) Our findings suggest that it makes no sense to construe age as a singular feature or cause for feelings of loneliness. Instead, age and also a number of other features combine to predict feelings of loneliness. But even with our predictor variables there was a substantial of variance left unexplained. Therefore it is necessary to continue exploring how feelings of loneliness arise from the experience of living and how they can be changed.

Modelos Teóricos acerca dos Determinantes dos Comportamentos Preventivos na Transmissão do Vírus da Imunodeficiência Humana

Vários modelos têm sido desenvolvidos com o objectivo de compreender a mudança de comportamentos associados à transmissão do Vírus da Imunodeficiência Humana (VIH). Os modelos cognitivo-sociais procuram explicar o desempenho de comportamentos preventivos a partir de constructos como a percepção de susceptibilidade, as intenções comportamentais e a percepção de controlo. Apesar das contribuições das teorias da mudança comportamental para a redução do risco de infecção pelo VIH, persiste a necessidade de desenvolvimento de modelos que contemplem a complexidade do comportamento sexual. Este artigo faz uma revisão dos modelos dos determinantes dos comportamentos preventivos na transmissão do VIH e dos estudos neles baseados. Aaplicabilidade e as implicações dos resultados, de acordo com o modelo utilizado, para o desenvolvimento de estratégias de educação e prevenção na área dos determinantes psicológicos dos comportamentos preventivos associados à transmissão do VIH, é discutida. Cada modelo parece ser predictor de diferentes aspectos do comportamento e os modelos desenvolvidos especificamente para o comportamento sexual, em relação aos modelos genéricos para a saúde, parecem ter vantagens na compreensão dos comportamentos sexuais de risco.

Segurança alimentar nos refeitórios de uma universidade portuguesa : aplicação da teoria do comportamento planeado

A Organização Mundial de Saúde estima que nos países mais industrializados uma em cada três pessoas sofra, por ano, de uma doença de origem alimentar. De acordo com os dados da Agência Europeia para a Segurança Alimentar foram relatados pelos 27 Estados Membros da União Europeia, no ano 2012, um total de 5.363 surtos de origem alimentar, assistindo-se a uma prevalência do setor da restauração, como o local de maior ocorrência dos surtos de doenças de origem alimentar. Para o mesmo ano, Portugal reportou 7 surtos de origem alimentar, envolvendo 135 pessoas com 42 hospitalizações. Neste contexto, a aplicação de boas práticas de higiene, nomeadamente no setor da restauração, é essencial para proteger o consumidor das doenças de origem alimentar. Neste estudo, pretendeu-se identificar os constructos do modelo da Teoria do Comportamento Planeado (Theory of Planned Behaviour – TPB, segundo a terminologia anglo-saxónica), de Icek Ajzen, que melhor explicam a intenção dos operadores de alimentos em adotarem os comportamentos de higiene, a saber: i) utilização de luvas e touca de proteção de cabelos, e ii) remoção de adornos pessoais, durante a manipulação de alimentos. Para o efeito, foi aplicado um questionário tendo por base a Teoria do Comportamento Planeado, a uma amostra de cento e vinte e três operadores dos vários refeitórios de uma universidade portuguesa, na sua grande maioria do sexo feminino (91,1%) e que manipulam alimentos numa base diária, recorrendo-se primeiramente a uma fase preliminar de estudo qualitativo, ou pré-inquérito, para melhor selecionar os temas essenciais e as principais categorias a considerar na construção deste inquérito. Os inquéritos foram tratados estatisticamente recorrendo-se à estatística descritiva, à análise fatorial e avaliação da consistência interna dos fatores resultantes, seguido da aplicação de regressão linear e metodologia de análise de trajetórias (path modeling) com vista à validação do TPB. Os resultados obtidos apontam para o fato de a Atitude ser o melhor preditor da Intenção em adotar os comportamentos em estudo. Verificou-se também que a motivação de cumprir resulta da pressão exercida pelos superiores hierárquicos ou colegas, influenciando positivamente a intenção, na medida em que as crenças normativas assumiram-se como sendo o segundo preditor que melhor previu a intenção.

Variáveis psicológicas e percepção do estado de saúde em indivíduos submetidos a ressincronização cardíaca

A insuficiência cardíaca afecta cerca de 261 mil pessoas em Portugal constituindo um problema de saúde pública. Pretendemos avaliar aspectos associados à recuperação do estado de saúde nesta síndrome, em particular a esperança, o afecto e a felicidade. Recorremos a um estudo longitudinal com 128 indivíduos sintomáticos com má fracção de ejecção do ventrículo esquerdo. Utilizámos um questionário para caracterizar os aspectos sóciodemográficos, clínicos e funcionais, o Kansas City Cardiomiopathy Questionnaire (KCCQ) para avaliar a qualidade de vida, a Subjective Hapiness Scale (SHS) para a felicidade, a HOPE Scale (HOPE) para a esperança e a Positive And Negative Afect Schedule (PANAS) para o afecto. Os questionários de caracterização sócio-demográfica, clínica e funcional, KCCQ e o SHS foram aplicados em três momentos: no internamento, prévio à instituição de terapêutica médica na sua totalidade e ao terceiro e sexto mês após a intervenção médica, na consulta externa. A maioria dos participantes eram homens em classe III da classificação da New York Heart Association com etiologia isquémica. No internamento e antes da terapêutica médica, observámos que a esperança, a felicidade e o afecto se relacionaram com a qualidade de vida, a felicidade e o afecto positivo com a esperança. No período avaliado foram submetidos a: terapia de ressincronização cardíaca (n=52), cardioversor-desfibrilhador implantável (n=44), cirurgia valvular com revascularização do miocárdio (n=14), optimização terapêutica farmacológica (n=10), transplante cardíaco (n=8). Foram significativos os resultados da qualidade de vida, da classificação da New York Heart Association, do exercício físico, da fracção de ejecção do ventrículo esquerdo e das arritmias cardíacas (estrasístoles e taquicardias ventriculares). A felicidade foi preditora da qualidade de vida e da funcionalidade. O afecto negativo foi preditor da satisfação com a insuficiência cardíaca. Concluímos da importância das variáveis positivas a par dos procedimentos médicos no tratamento das pessoas com insuficiência cardíaca. ABSTRACT - Heart failure affects about 261 000 people in Portugal constituting a public health problem. We intend to evaluate aspects of the health recovery in this syndrome, in particular hope, affection and happiness. We used a longitudinal study with 128 symptomatic patients with poor ejection fraction of left ventricle. We used a questionnaire to characterize the socio-demographic, clinical and functional aspects, the Kansas City Cardiomiopathy Questionnaire (KCCQ) to assess the quality of life, the Subjective Happiness Scale (SHS) for happiness, the HOPE Scale (HOPE) for hope and the Positive And Negative Affect Schedule (PANAS) for affection. The questionnaires of sociodemographic, clinical and functional KCCQ and SHS were applied on three occasions: on admission, prior to the execution of medical therapy in its totality and in the third and sixth months after medical intervention in the outpatient. Most of the participants were men in Class III New York Heart Association classification with ischemic etiology. At admission and before medical therapy, we observed that the hope, happiness and affection were related to the quality of life, happiness and positive affect with hope. Over the studied period were submitted to: cardiac resynchronization therapy (n=52), implantable cardioverter-defibrillator (n=44), valvular surgery with coronary artery bypass graft surgery (n=14), optimizing drug therapy (n=10), heart transplant (n=8). The significant results were the quality of life, the New York Heart Association classification, the exercise, the ejection fraction and left ventricular cardiac arrhythmias (ventricular tachycardia and estrasistoles). Happiness was a predictor of quality of life and functionality. The negative affect was a predictor of satisfaction with heart failure. We concluded that the positive variables and the medical procedures were important in treating people with heart failure.

Monitorização da insuficiência cardíaca por parâmetros fisiológicos em portadores de cardioversor-desfibrilhador implantável e/ou sistema de ressincronização cardíaca: HF-PREDICT

Mestrado em Tecnologia de Diagnóstico e Intervenção Cardiovascular. Área de especialização: Intervenção Cardiovascular.

Developmental and evolutionary assumptions in a study about the impact of premature birth and low income on mother–infant interaction

In order to study the impact of premature birth and low income on mother–infant interaction, four Portuguese samples were gathered: full-term, middle-class (n=99); premature, middle-class (n=63); full-term, low income (n=22); and premature, low income (n=21). Infants were filmed in a free play situation with their mothers, and the results were scored using the CARE Index. By means of multinomial regression analysis, social economic status (SES) was found to be the best predictor of maternal sensitivity and infant cooperative behavior within a set of medical and social factors. Contrary to the expectations of the cumulative risk perspective, two factors of risk (premature birth together with low SES) were as negative for mother–infant interaction as low SES solely. In this study, as previous studies have shown, maternal sensitivity and infant cooperative behavior were highly correlated, as was maternal control with infant compliance. Our results further indicate that, when maternal lack of responsiveness is high, the infant displays passive behavior, whereas when the maternal lack of responsiveness is medium, the infant displays difficult behavior. Indeed, our findings suggest that, in these cases, the link between types of maternal and infant interactive behavior is more dependent on the degree of maternal lack of responsiveness than it is on birth status or SES. The results will be discussed under a developmental and evolutionary reasoning

Agressividade e índice de Apgar

A agressividade é o comportamento que surge transversalmente como queixa isolada ou a par de outras queixas na maioria das crianças com e sem doença, que procuram apoio em saúde mental infantil. Nessas crianças, e a partir da recolha dos dados anamnesicos, tem-se verificado a constância de registo, no Livro do Bebé, de Índice de Apgar ≤ 9 ao primeiro minuto. Este estudo exploratório pretendeu analisar a hipótese teórica de que o Índice de Apgar abaixo de 10 ao primeiro minuto pode ser representativo de sofrimento fetal intraparto ou perinatal e assim fragilizar os circuitos neuronais das emoções tendo como consequência o surgimento, ao longo do desenvolvimento infantil e juvenil, de dificuldades na capacidade de gestão ou controlo das emoções, com comportamentos opositivos e/ou agressivos, como resposta defensiva de luta e fuga. Utilizou-se uma amostra de crianças inscritas no serviço de consulta externa de saúde mental infantil e juvenil, e verificou-se se as queixas de perturbação do comportamento com agressividade, formuladas no momento do acolhimento ao serviço, estão relacionadas com o Índice de Apgar ≤ 9 ao primeiro minuto e/ou com os registos de sofrimento fetal. Procurou-se, numa amostra aleatória de crianças sem queixa formulada no serviço de consulta externa de saúde mental infantil e juvenil, perceber as diferenças ou semelhanças dos registos de nascimento relativamente à amostra de crianças inscritas. Foi ainda auscultada a opinião dos profissionais dos serviços de obstetrícia e neonatologia – pediatria, mediante a aplicação de um questionário, no sentido de recolher as opiniões dos profissionais de saúde que lidam com o parto, que avaliam o Índice de Apgar dos recém – nascidos e que os seguem durante as primeiras horas ou dias de vida. Das conclusões a que chegamos, salienta-se que o sofrimento fetal intraparto pode ser predictor de dificuldades de controlo emocional traduzidas em alterações do comportamento com agressividade em situações de stress. Não se conclui que o Índice de Apgar ≤ 9 pode ser predictor de alterações do comportamento com agressividade em situações de stress, uma vez que os registos de ocorrências de sofrimento fetal intraparto e os registos do Índice de Apgar ao primeiro minuto são, na amostra de crianças com queixa, díspares, relacionando-se no entanto de modo estatisticamente significativo na amostra de crianças sem queixa. III No entanto, e apesar das dificuldades metodológicas, fica a certeza de haver mais percursos a percorrer nesta direcção para a compreensão dos distúrbios emocionais e a agressividade.

Conhecimentos sobre VIH sida nos clientes de um hospital de Lakes State, Sudão do Sul

Enquadramento: O VIH/Sida exige uma ação direcionada na vertente da prevenção, cujo suporte integra a transmissão de conhecimentos promotores da adoção e manutenção de comportamentos seguros, em conformidade com as características sociais e culturais dos indivíduos. Objetivos: Validar, para a população do Sudão do Sul, a Escala de Conhecimentos sobre VIH/Sida, The HIV Knowledge Questionnaire: HIV-KQ-45, de Carey et al. (1997); analisar de que forma as variáveis sociodemográficas influenciam os conhecimentos sobre VIH/Sida, dos cidadãos de Mapuordit Sudão do Sul; verificar se a frequência de formação sobre VIH/Sida influencia o seu nível de conhecimentos. Metodologia: Estudo quantitativo, descritivo-analítico e transversal, com 232 clientes do Mary Immaculate de Mapuordit Hospital. Foi utilizado um Questionário de caracterização sociodemográfica e do contexto de formação sobre o VIH/Sida, e o HIV Knowledge Questionnaire (HVI-K-Q) de Carey, Morrison-Beedy e Johnson (1997). Resultados: Amostra é maioritariamente masculina (74.6%), com uma média de idade 22,83 (±5.793 anos). A análise fatorial confirmatória do HIV-K-Q permitiu apurar 5 fatores, cujos valores médios mais significativos foram nos fatores preconceitos/medos (média=80.60%), conhecimentos sobre os comportamentos de risco (média=76.58%) e vias de transmissão (média=70.36%). Os sudaneses pontuaram maioritariamente com razoáveis conhecimentos sobre a Sida (média=68.08%). As mulheres, os participantes mais velhos, com companheiro(a), mais escolarizados, profissionalmente ativos, a distar do hospital =<20 Km, deslocando-se num veículo não motorizado e com diagnóstico de VIH relataram mais conhecimentos sobre a Sida. Os participantes com informação sobre a prevenção do VIH/Sida e frequência em workshop na área demonstraram melhores conhecimentos. Revelaram-se preditivas dos conhecimentos acerca da doença as habilitações literárias (β=0.32) e o diagnóstico de VIH/Sida (β=0.14) revelou-se preditor dos conhecimentos sobre os comportamentos de risco. Conclusão: As casuísticas significativas do VIH/Sida justificam considerar as habilitações literárias e a presença de diagnóstico VIH/Sida como variáveis a avaliar previamente ao planeamento estratégico das ações de educação para a prevenção do VIH/Sida no Sudão do Sul. Palavras-chave: Conhecimentos; VIH/Sida; Sudão do Sul.