1,003 research outputs found
The epidemiological impact of an HIV vaccine on the HIV/AIDS epidemic in Southern India
The potential epidemiological impact of preventive HIV vaccines on the HIV epidemic in Southern India is examined using a mathematical deterministic dynamic compartmental model. Various assumptions about the degree of protection offered by such a vaccine, the extent of immunological response of those vaccinated, and the duration of protection afforded are explored. Alternative targeting strategies for HIV vaccination are simulated and compared with the impact of conventional prevention interventions in high-risk groups and the general population. The impact of disinhibition (increased risk behavior due to the presence of a vaccine) is also considered. Vaccines that convey a high degree of protection in a share of or all of those immunized and that convey life-long immunity are the most effective in curbing the HIV epidemic. Vaccines that convey less than complete protection may also have substantial public health impact, but disinhibition can easily undo their effects and they should be used combined with conventional prevention efforts. Conventional interventions that target commercial sex workers and their clients to increase condom use can also be highly effective and can be implemented immediately, before the arrival of vaccines.Poverty and Health,Disease Control&Prevention,Health Monitoring&Evaluation,Public Health Promotion,HIV AIDS,HIV AIDS,Health Monitoring&Evaluation,Adolescent Health,HIV AIDS and Business,Health Service Management and Delivery
On the Parameterized Complexity of the Perfect Phylogeny Problem
This paper categorizes the parameterized complexity of the algorithmic
problems Perfect Phylogeny and Triangulating Colored Graphs when parameterized
by the number of genes and colors, respectively. We show that they are complete
for the parameterized complexity class XALP using a reduction from Tree-chained
Multicolor Independent Set and a proof of membership. We introduce the problem
Triangulating Multicolored Graphs as a stepping stone and prove
XALP-completeness for this problem as well. We also show that, assuming the
Exponential Time Hypothesis, there exists no algorithm that solves any of these
problems in time , where is the input size, the
parameter, and any computable function
Uniting mathematics and biology for control of visceral leishmaniasis
The neglected tropical disease (NTD) visceral leishmaniasis (VL) has been targeted by the WHO for elimination as a public health problem on the Indian subcontinent by 2017 or earlier. To date there is a surprising scarcity of mathematical models capable of capturing VL disease dynamics, which are widely considered central to planning and assessing the efficacy of interventions. The few models that have been developed are examined, highlighting the necessity for better data to parameterise and fit these and future models. In particular, the characterisation and infectiousness of the different disease stages will be crucial to elimination. Modelling can then assist in establishing whether, when, and how the WHO VL elimination targets can be met
Nevenwerking van gewasbeschermingsmiddelen en bladmeststoffen op oorwormen
PT projectnummer 12857, in samenwerking met pcfruit en PR
Spatial and temporal variations of malaria epidemic risk in Ethiopia: factors involved and implications.
The aim of this study was to describe spatial and temporal variations in malaria epidemic risk in Ethiopia and to examine factors involved in relation to their implications for early warning and interpretation of geographical risk models. Forty-eight epidemic episodes were identified in various areas between September 1986 and August 1993 and factors that might have led to the events investigated using health facility records and weather data. The study showed that epidemics in specific years were associated with specific geographical areas. A major epidemic in 1988 affected the highlands whereas epidemics in 1991 and 1992 affected highland-fringe areas on the escarpments of the Rift Valley and in southern and north-western parts of the country. Malaria epidemics were significantly more often preceded by a month of abnormally high minimum temperature in the preceding 3 months than based on random chance, whereas frequency of abnormally low minimum temperature prior to epidemics was significantly lower than expected. Abnormal increases of maximum temperature and rainfall had no positive association with the epidemics. A period of low incidence during previous transmission seasons might have aggravated the events, possibly due to low level of immunity in affected populations. Epidemic risk is a dynamic phenomenon with changing geographic pattern based on temporal variations in determinant factors including weather and other eco-epidemiological characteristics of areas at risk. Epidemic early warning systems should take account of non-uniform effects of these factors by space and time and thus temporal dimensions need to be considered in spatial models of epidemic risks
Diagnosis of urinary schistosomiasis: a novel approach to compare bladder pathology measured by ultrasound and three methods for haematuria detection
Diagnosis of urinary schistosomiasis: a novel approach to compare bladder pathology measured by ultrasound and three methods for haematuria detection
Weide van vlees:De betekenis van de regeneratie van afgebeten lichaamsdelen van bodemdieren voor de vleesproductie in de Waddenzee
Diagnosis of urinary schistosomiasis: a novel approach to compare bladder pathology measured by ultrasound and three methods for hematuria detection
We aggregated published data from field studies documenting prevalence of
Schistosoma haematobium infection and bladder pathology determined by
ultrasonography or hematuria detected by reagent strip, questionnaire, or
visual examination. A mathematical expression was used to describe the
associations between prevalence of pathology/morbidity and infection. This
allows for indirect comparison of these methods, which are rarely used
simultaneously. All four methods showed a similar, marked association with
infection. Surprisingly, ultrasound revealed higher prevalences of
pathology in schools than in communities with the same prevalence of
infection, implying a need for age-related cut-off values. Reagent strip
testing yielded a higher prevalence than questionnaire, which in turn was
higher than by visual examination. After correction for morbidity due to
other causes, a consistent ratio in prevalence of hematuria of 3:2:1
resulted for the three respective methods. The simple questionnaire
approach is not markedly inferior to the other techniques, making it the
best option for field use
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