42 research outputs found
Prediction of Soil Temperature at Various Depths Using a Mathematical Model
This study discusses variation of soil temperature with depth using mathematical models at Ataoja School of Science, Osogbo, Osun State, Nigeria. Average conditions were assumed. The annual soil temperature cycles were modeled with fairly good accuracy. Differences in measured and predicted soil temperatures were determined at annual levels at depths 0cm (top soil), 10cm, 30cm and 50cm. For the annual cycle, the absolute errors ranged from 0.5oC to 7.8 oC with an average of 2.7 oC at the soil surface (0cm). At the 10cm depth, the errors ranged from 0.1 oC to 4.5 oC with an average value of 2.0 oC . At the 30cm depth, the absolute errors ranged from 0.05 oC to 2.9 oC with an average of 1.7 oC. The highest average absolute error was 2.7 oC while the lowest average absolute error was 1.7 oC.Keywords: Soil temperature, transient heat flow, simulation, homogenous
Changes in mediators of inflammation and pro-thrombosis after 12 months of dietary modification in adults with metabolic syndrome.
Objective: This study evaluated the effects of a 12-month dietary
modification on indices of inflammation and pro-thrombosis in adults
with metabolic syndrome (MS). Materials and methods: This longitudinal
study involved 252 adults with MS recruited from the Bodija market,
Ibadan and its environs. Participants were placed on 20%, 30% and 50%
calories obtained from protein, total fat and carbohydrate respectively
and were followed up monthly for 12 months. Anthropometry and blood
pressure were measured using standard methods. Fasting plasma glucose
(FPG), total cholesterol (TC), triglycerides (TG), high density
lipoprotein-cholesterol (HDL-C), fibrinogen, plasminogen activator
inhibitor-1 (PAI-1)], interleukin-6 (IL-6) and interleukin-10 (IL-10)
were measured using spectrophotometric methods and ELISA as
appropriate. Data was analysed using ANCOVA, Student\u2019s t-test,
Mann-Whitney U and Wilcoxon signed-rank tests. P-values less than 0.05
were considered significant. Results: After 6 months of dietary
modification, there was a significant reduction in waist circumference
(WC), while the levels of HDL-C, fibrinogen and PAI-1 were
significantly increased when compared with the corresponding baseline
values. However, WC and fibrinogen reduced significantly, while HDL-C
and IL-10 significantly increased after 12 months of dietary
modification as compared with the respective baseline values.
Conclusion: Long-term regular dietary modification may be beneficial in
ameliorating inflammation and pro-thrombosis in metabolic syndrome
The multiplicity of malaria transmission: a review of entomological inoculation rate measurements and methods across sub-Saharan Africa
Plasmodium falciparum malaria is a serious tropical disease that causes more than one million deaths each year, most of them in Africa. It is transmitted by a range of Anopheles mosquitoes and the risk of disease varies greatly across the continent. The "entomological inoculation rate" is the commonly-used measure of the intensity of malaria transmission, yet the methods used are currently not standardized, nor do they take the ecological, demographic, and socioeconomic differences across populations into account. To better understand the multiplicity of malaria transmission, this study examines the distribution of transmission intensity across sub-Saharan Africa, reviews the range of methods used, and explores ecological parameters in selected locations. It builds on an extensive geo-referenced database and uses geographical information systems to highlight transmission patterns, knowledge gaps, trends and changes in methodologies over time, and key differences between land use, population density, climate, and the main mosquito species. The aim is to improve the methods of measuring malaria transmission, to help develop the way forward so that we can better assess the impact of the large-scale intervention programmes, and rapid demographic and environmental change taking place across Africa
The influence of mosquito resting behaviour and associated microclimate for malaria risk
<p>Abstract</p> <p>Background</p> <p>The majority of the mosquito and parasite life-history traits that combine to determine malaria transmission intensity are temperature sensitive. In most cases, the process-based models used to estimate malaria risk and inform control and prevention strategies utilize measures of mean outdoor temperature. Evidence suggests, however, that certain malaria vectors can spend large parts of their adult life resting indoors.</p> <p>Presentation of hypothesis</p> <p>If significant proportions of mosquitoes are resting indoors and indoor conditions differ markedly from ambient conditions, simple use of outdoor temperatures will not provide reliable estimates of malaria transmission intensity. To date, few studies have quantified the differential effects of indoor <it>vs </it>outdoor temperatures explicitly, reflecting a lack of proper understanding of mosquito resting behaviour and associated microclimate.</p> <p>Testing the hypothesis</p> <p>Published records from 8 village sites in East Africa revealed temperatures to be warmer indoors than outdoors and to generally show less daily variation. Exploring the effects of these temperatures on malaria parasite development rate suggested indoor-resting mosquitoes could transmit malaria between 0.3 and 22.5 days earlier than outdoor-resting mosquitoes. These differences translate to increases in transmission risk ranging from 5 to approaching 3,000%, relative to predictions based on outdoor temperatures. The pattern appears robust for low- and highland areas, with differences increasing with altitude.</p> <p>Implications of the hypothesis</p> <p>Differences in indoor <it>vs </it>outdoor environments lead to large differences in the limits and the intensity of malaria transmission. This finding highlights a need to better understand mosquito resting behaviour and the associated microclimate, and to broaden assessments of transmission ecology and risk to consider the potentially important role of endophily.</p
The dominant Anopheles vectors of human malaria in Africa, Europe and the Middle East: occurrence data, distribution maps and bionomic précis
<p>Abstract</p> <p>Background</p> <p>This is the second in a series of three articles documenting the geographical distribution of 41 dominant vector species (DVS) of human malaria. The first paper addressed the DVS of the Americas and the third will consider those of the Asian Pacific Region. Here, the DVS of Africa, Europe and the Middle East are discussed. The continent of Africa experiences the bulk of the global malaria burden due in part to the presence of the <it>An. gambiae </it>complex. <it>Anopheles gambiae </it>is one of four DVS within the <it>An. gambiae </it>complex, the others being <it>An. arabiensis </it>and the coastal <it>An. merus </it>and <it>An. melas</it>. There are a further three, highly anthropophilic DVS in Africa, <it>An. funestus</it>, <it>An. moucheti </it>and <it>An. nili</it>. Conversely, across Europe and the Middle East, malaria transmission is low and frequently absent, despite the presence of six DVS. To help control malaria in Africa and the Middle East, or to identify the risk of its re-emergence in Europe, the contemporary distribution and bionomics of the relevant DVS are needed.</p> <p>Results</p> <p>A contemporary database of occurrence data, compiled from the formal literature and other relevant resources, resulted in the collation of information for seven DVS from 44 countries in Africa containing 4234 geo-referenced, independent sites. In Europe and the Middle East, six DVS were identified from 2784 geo-referenced sites across 49 countries. These occurrence data were combined with expert opinion ranges and a suite of environmental and climatic variables of relevance to anopheline ecology to produce predictive distribution maps using the Boosted Regression Tree (BRT) method.</p> <p>Conclusions</p> <p>The predicted geographic extent for the following DVS (or species/suspected species complex*) is provided for Africa: <it>Anopheles </it>(<it>Cellia</it>) <it>arabiensis</it>, <it>An. </it>(<it>Cel.</it>) <it>funestus*</it>, <it>An. </it>(<it>Cel.</it>) <it>gambiae</it>, <it>An. </it>(<it>Cel.</it>) <it>melas</it>, <it>An. </it>(<it>Cel.</it>) <it>merus</it>, <it>An. </it>(<it>Cel.</it>) <it>moucheti </it>and <it>An. </it>(<it>Cel.</it>) <it>nili*</it>, and in the European and Middle Eastern Region: <it>An. </it>(<it>Anopheles</it>) <it>atroparvus</it>, <it>An. </it>(<it>Ano.</it>) <it>labranchiae</it>, <it>An. </it>(<it>Ano.</it>) <it>messeae</it>, <it>An. </it>(<it>Ano.</it>) <it>sacharovi</it>, <it>An. </it>(<it>Cel.</it>) <it>sergentii </it>and <it>An. </it>(<it>Cel.</it>) <it>superpictus*</it>. These maps are presented alongside a bionomics summary for each species relevant to its control.</p
The impact of urbanization and population density on childhood Plasmodium falciparum parasite prevalence rates in Africa
Presence and distribution of mosquito larvae predators and factors influencing their abundance along the Mara River, Kenya and Tanzania
âA bite before bedâ: exposure to malaria vectors outside the times of net use in the highlands of western Kenya
Medicinal plants â prophylactic and therapeutic options for gastrointestinal and respiratory diseases in calves and piglets? A systematic review
Comparative chemical composition of 24-hour fermented sweet orange fruit (Citrus sinensis) peel meal and maize and effect on performance response of starting pullet chicks
The study evaluated the effect of 24-hour fermentation of sweet orange fruit (Citrus sinensis) peel meal (24SOFPM) on its chemical composition and performance response to graded levels of peel meal in the diets of pullet chicks. Dry matter, crude protein and phosphorus level in 24SOFPM were close to that of maize. While limonene was higher in 24SOPFM, phytate was higher in maize than the 24SOPFM. One hundred and forty-four fourteen dayold Nera black pullet chicks were assigned to four experimental diets F0, F10, F20 and F30. SOPFM substituted maize in F0, F10, F20 and F30 respectively at 0, 10, 20 and 30%. The feeding trial lasted the remaining 6 weeks of the chicksâ phase. The study design was Completely Randomized Design. Daily feed intake was not significantly different (p>0.05). Average body weight gain was significantly different (p<0.05) and was depressed with no definite pattern in the SOPFM based diets. FCR was significantly different (p<0.05). Substitution of maize with SOFPM significantly (p<0.05) reduced feed cost/25kg, feed cost/bird and cost of production while decreasing efficiency of feed utilization for growth. Apparently, SOPFM might be a potential feedstuff which could substitute a proportion of maize in pullet chickâs diet when fermented for 24 hours.Keywords: chemical composition, performance, chick, sweet orange fruit peel mea