Protectivity of Freeze Dried Inactivated Rift Valley Fever Vaccine

Background: Vaccinations for animals are crucial for food production, animal welfare, public health, and animal health. They are an affordable way to stop animal sickness, increase food production efficiency, and lessen or stop the spread of zoonotic diseases to humans. Animal vaccines that are both safe and efficacious are vital to modern culture. The vaccine should induce a strong, protective and prolonged immune response against the antigenic factor. In order to achieve these goals, novel vaccination techniques and an efficient adjuvant are required to render the vaccine immunogenically protective and trigger a strong immune response. Aim: Our study aims to promote and enhance the immunogenicity against RVF virus disease through lyophilized inactivated RVF vaccine through induction of early cellular, high and prolonged humeral immunity in vaccinated animals using cabopol as stabilizer and Saponin or normal saline as a diluent at time of vaccination. Moreover, manufacturing of these vaccines is easy to be done. Results: The gained results revealed that RVF freeze-dried vaccine with Carbopol that reconstituted using Saponin elicited better immune response than that reconstituted using normal saline (NaCl). The cell mediated immune response as represented by lymphocyte blastogenesis and phagocytic activity were markedly increased with high levels when we used Saponin as a diluent than that in group vaccinated with vaccine diluted with NaCl, on the other side the humeral immune response in group vaccinated using the Saponin as diluent is more detected and stayed within the protective level till the end of 11th month post vaccination (1.5 TCID50) while the immune response induced after using normal saline as a diluent stayed within the protective level till the end of 10th month post vaccination (1.8 TCID50). Conclusion: The use of Saponin as a diluent for reconstitution of the freeze dried RVF vaccine is preferable than the use of normal saline enhancing both sheep cellular and humeral immune response.

Emerging Rift Valley fever in China:What should be known?

Rift Valley fever is an important viral infection that is rarely reported in Asia.The recent emergence of this infection in China is a big global interest.In this short article,the author reviewed and presented important information on this disease.

Enhanced surveillance and cohesive policies needed to tackle Rift Valley fever

Dear editor,There has been an upsurge in Rift Valley fever (RVF) outbreaks in Kenya in the recent past.Even as I write this letter,the country is experiencing an outbreak which was confirmed by the Ministry of Health on 8 June 2018[1].The current outbreak was first reported in Wajir County on 2nd June but has currently spread to other

Evaluation of the Factors Controlling Concentration of Non-Condensable Gases and Their Possible Impact on the Performance of Geothermal Systems: Case Study of Olkaria Wells in the Kenyan Rift Valley

The Olkaria geothermal field is located in the Kenyan Rift valley, about 120 km from Nairobi. Development of geothermal resources in the Olkaria area, a high temperature field, started in the early 1950s. In the subsequent years numerous expansions have been carried out with additional power plants being installed in Olkaria. These include a binary plant at Olkaria South West (Olkaria III) in 2000, a condensing plant at Olkaria North East (Olkaria II) in 2003, another binary plant at Olkaria North West (Oserian) in 2004 and finally condensing plants in the year 2014 within East production field (EPF) and Olkaria Domes (OD) areas. The total generation from this field is about 730 Mw. The study considered samples from 4 producing wells from 3 fields of the Olkaria geothermal area (OW-44 from the Olkaria East, OW-724A from the Olkaria North East, and OW-914 and OW-915 from the Olkaria Domes field). The chemical data were first analyzed using SOLVEQ. This helped in the determination of the equilibrium state of the system, the reservoir temperatures and the total moles to be run through CHILLER. The run CHILLER considered the processes that have been proven to be occurring in the Olkaria field i.e., boiling and condensing processes, fluid-fluid mixing rocks and titration resulting from water-rock interaction. The effects on gas evolution were evaluated based on the resulting recalculated gas pressures. The results indicate that the gas species are not in equilibrium with the mineral assemblages. The CHILLER evaluation shows boiling as the major process leading to the evolution of gases. OW-44 had the least gas concentrations, arising from the considered reservoir processes due to degassing, and near surface boiling, besides the removal of NH3, H2 and H2S are through the reaction with steam condensate. The gas breakout is most likely in OW-914 and least in OW-44. The study proposes different reservoir management strategies for the different parts of the Olkaria geothermal field. That is by increasing hot reinjection in the eastern sector around well OW-44. The reservoir around OW-914 is to be managed by operating the wells at a minimum flow rate (or even to close them) or the use of chemical inhibitors to prevent calcite scaling.

Model test study on the formation and development of underground erosion ground fissures in the Kenya Rift Valley

The Kenya Rift Valley is relatively prone to underground erosion ground fissures and associated disasters,which gravely hinder local engineering construction and economic development.In this research,we performed field and experimental studies on ground fissures in the Kenya Rift Valley area,and determined the structural characteristics of underground erosion fissures.Based on a geological survey of the area,we generalized a geological model for typical ground fissures and reproduced the intermediate process of ground fissure propagation using a large-scale physical model test.Further,the development process of underground erosion fissures were categorized into four stages:uniform infiltration,preferential infiltration,cavity expansion,and collapse formation stages.During the development of underground erosion fissures,water content was distributed symmetrically along the fissures,and these fissures acted as the primary infiltration paths of water.When the ground collapsed,the increase in negative pore water pressure was greater,whereas the increase in positive pore water pressure was less in the shallow soil;moreover,in the deep soil,the increase in positive pore water pressure was greater than that of negative pore water pressure.Additionally,the earth pressure increment initially increased and then decreased with the development of erosion.During underground erosion collapse,the water content and pore water pressure appeared to increase and decrease rapidly.These results can be employed to predict the occurrence of underground erosion ground fissures and the resulting soil collapse.

Chronic Alcohol Consumption and the Development of Skeletal Fluorosis in a Fluoride Endemic Area of the Ethiopian Rift Valley

This study compared the occurrence of skeletal fluorosis in chronic consumers of locally brewed alcoholic beverages and their matched controls in the Ethiopian Rift Valley. The study revealed that chronic alcohol consumers developed severe forms of crippling skeletal fluorosis quite early in life. The controls were either symptom-free or exhibited mild forms of the fluorosis. The study showed that crippling skeletal fluorosis was directly associated with the large volumes of the locally brewed beer and honey-mead consumption on a daily basis. Chemical analysis of the alcoholic beverages showed that high concentration of fluoride which was much higher than the fluoride in the water was used for the brewing process. From this study one would conclude that in communities residing in high fluoride areas, there should be awareness creation campaigns to point out the relationship of excessive consumption of locally brewed alcoholic drinks and skeletal fluorosis. Regulations should also be put in place to require producers of local alcoholic beverages to use low fluoride water for brewing.

Exposure of abattoirs workers to rift valley fever virus infection in Southwestern Saudi Arabia

Objective: To measure seroprevalence of Rift Valley Fever virus infection among abattoirs workers in Southwestern Saudi Arabia. Materials and Methods: Abattoirs in the region (Jazan, Aseer and Al Qunfuda) were visited. Veterinarians and butchers were studied. Blood samples were then taken and tested for RVF-specific IgG and IgM (ELISAs). Results: The present study included 62 abattoir workers. None of whom tested were positive for RVF specific IgM. The overall prevalence of RVF IgG among butchers reached 8% (95% CI: 1.3 - 75.8). Among the 31 Bengali butchers 3 were RVF IgG positive giving a prevalence of 9.7 % (95% CI: 2.0 - 25.8), while among four Saudi butchers one was RVF IgG positive (25%, 95% CI: 1.3 - 75.8). Conclusions: The study documented the lack of recent RVF activity among abattoirs workers. High-risk, occupationally exposed abattoir workers represent a useful sentinel population for surveillance of RVF, especially in the absence of clinical disease.

THE CHARACTERISTICS OF GEOLOGICAL GENERAL FIELD OF VOLCANIC BELT IN LANCANG RIFT VALLEY AND ITS SIGNIFICANCE FOR EXPLORATION

Based on the theory of dissipative structures and moving character-parameters of elements,this paper examines the characteristics of the geological general field of volcanic belt in the Lancang rift valley,west Yunnan,China-with an open system and lower pressure environment,the volcanic belt is characterized by a large scale continuously graduating dissipative structure and three orders of concentrated minerogenetic material fields,and by the energy fields that influence the time and space structure of material fields.The research shows that the third order minerogenetic material fields which surround volcanic eruptive centers and have hydrothermal superposition and reconstruction after the magma stage possess favorable prognosis targets for copper polymetal.

Modeling Rift Valley Fever with Treatment and Trapping Control Strategies

We consider a rift valley fever model with treatment in human and livestock populations and trapping in the vector (mosquito) population. The basic reproduction number R 0 is established and used to determine whether the disease dies out or is established in the three populations. When R 0 ≤ 1, the disease-free equilibrium is shown to be globally asymptotically stable and the disease does not spread and when R 0 > 1, a unique endemic equilibrium exists which is globally stable and the disease will spread. The mathematical model is analyzed analytically and numerically to obtain insight of the impact of intervention in reducing the burden of rift valley fever disease’s spread or epidemic and also to determine factors influencing the outcome of the epidemic. Sensitivity analysis for key parameters is also done.

An Agent-Based Model for Studying the Impact of Herd Mobility on the Spread of Vector-Borne Diseases: The Case of Rift Valley Fever (Ferlo Senegal)

Vector-borne diseases are highly sensitive to environment and to environmental changes. Rift Valley Fever (RFV) is a mosquito-borne zootic virus associated with severe diseases in human beings and economic consequences to livestock sector. Animal and human movements have a fundamental impact on RVF transmission. In recent years, there has been a growing interest in the use of mathematics and agent based models to represent and analyze the dynamic of RFV transmission. However, no previous study has taken into consideration animal herds’ mobility and precipitation factors to understand the disease spread. This limitation underlines the necessity to use computational model approach based on multi-agent system in the study of vector-borne diseases transmission and diffusion. In this paper, a multi-agent system combining conceptual model expressiveness is used to study animal herds’ mobility and the precipitation parameter impact on the Rift Valley Fever outbreak in Ferlo Barkedji in Northern Senegal. Simulation scenarios with various parameters, including rain quality, hosts, vectors, camp dispersal around ponds, etc., are unrolled. The different results we have obtained show that the evolution of the number of infected hosts and infected vectors depend on the degree of animal herds’ mobility and on precipitations. Our model provides a framework that permits predicting the spread of the disease associated with the mobility of animal herds.

Modeling for Inter-Basin Groundwater Transfer Identification: The Case of Upper Rift Valley Lakes and Awash River Basins of Ethiopia

Groundwater movement beneath watershed divide is one component of the hydrological cycle that is typically ignored due to difficulty in analysis. Numerical ground-water models, like TAGSAC, have been used extensively for predicting aquifer responses to external stresses. In this paper TAGSAC code was developed to identify the inter-basin groundwater transfer (IBGWT) between upper Awash River basin (UARB) and upper rift valley lakes basin (URVLB) of Ethiopia. For the identification three steady state groundwater models (for UARB, URVLB and for the two combined basins) were first created and calibrated for the 926 inventoried wells. The first two models are conceptualized by considering the watershed divide between the two basins as no-flow. The third model avoids the surface water divide which justifies IBGWT. The calibration of these three models was made by changing the recharge and hydrogeologic parameters of the basins. The goodness of fit indicators (GoFIs) obtained was better for the combined model than the model that describes the URVLB. Furthermore, the hydraulic head distribution obtained from the combined model clearly indicates that there is a groundwater flow that doesn’t respect the surface water divide. The most obvious effect of IBGWT observed in these two basins is that it diminishes surface water discharge from URVLB, and enhances discharge in the UARB. Moreover, the result of this study indicates potential for internal and cross contamination of the two adjacent groundwater.

Cattle Feed Resource,Water Sources and Housing System in the Central Rift Valley of Oromia Regional State,Ethiopia

The study was conducted in Adami Tulu Jidokombolcha(ATJK),Bora,Dodola,Shala and Negele-Arsi districts with objective to assess main cattle feed resources,water sources and housing systems.A pre-tested,semi-structured questionnaire was used to conduct survey.About 240 respondents were identified using random sampling techniques.Collected data was analyzed by SPSS statistical software(Ver.24).Study result indicates that household in average had three hectares of land and allocated about two hectares of land for crop cultivation.Most respondents reported that cattle herding is not common during dry season while it is common during wet season.Survey result indicate that natural pasture,weed and maize tiller and stored crop residues are main feed resources in wet season while crop after math,crop residue and fodder trees are main resources during dry season.Brackish,local mineral and common salt are mineral sources for cattle in study areas.Lake,river and boreholes are important water sources in dry season where as ponds and rivers are main water sources during wet season for their cattle.The observed cattle watering frequency is mainly once a day.Housing system practiced in the study areas is mainly Kraal.The information generated from this study on land size per household,cattle herding system,feed resources,mineral sources,water sources,water utilization and housing type can be used as a baseline for any livestock development programs in those and similar areas.

An Exploration Frontier in Eastern China─Inner Mongolia Rift Basin Group

A number of small Jurassic-Cretaceous fau.lted-depressions have been found through seismic survey in the Zhangqiang area,200 km southeast to the Kailu City.Among them,the Zhangqiang Depression covers an area more than 1000 km?and commercial oil flows were obtained from the Jurassic Jiufutang Formation with single-well flow rate of 2 tons per day.It is predicted that new discoveries will be made by further exploration.Further to the east of the Zhangqiang Depression.oilfields and wells with commercial flow have'been continuously discovered in a series of Jurassi-C-Cre-taceous faulted-depressions;underlying the Songliao downwarp basin,such as the Changtu-Tieling and Lishu-Dehui depressions.

Land Use and Environmental Gradients Influence on Riparian Woody Plant Diversity and Structure in Lake Manyara Watershed Ecosystem, Tanzania

Riparian vegetations are important in supporting ecological connectivity between aquatic and terrestrial ecosystems. The structure and species composition of riparian woody plants have been subjected to multiple forces with varying degree of influences. This study examined the influence of land use and environmental gradient to the structure and composition of the riparian woody plants in northern Tanzania. A total of 270 plots were surveyed for woody plant species in the riparian ecosystems and later analysed to determine the influence of land use categories (homegarden, crop field, woodlot, open canopy forest, and closed canopy forest) and environmental variables (temperature, precipitation, elevation and slope) to the species richness, abundance, and stand parameters. Basal area was higher in woodlots, homegardens and crop fields than in the open and closed canopy forests;and as expected the reverse was true for the number of stocking density. Correlation among stand parameters with environmental variables varied significantly. Species richness and species abundance were negatively correlated to precipitation, temperature and elevation, while stocking density and basal area were positively correlated to precipitation. The study recommends continual retentions of trees on farm, further promoting of agroforestry interventions and sustainable utilization of woody plants in open and close canopy forests.

Helium Isotope Evidence of Mantle Degassing in Rift Valley, Eastern China

Radiogenic 40Ar and 4He found in atmosphere are considered to be produced byradioactive elements（e. g. U, Th）in the inner earth. Isotope composition of no-ble gases and ratios of their components are important geochemical indicators for thetheory of earth degassing and geochemical evolution of the mantle. The continuousand 'catastrophic' models of earth degassing have been suggested. The mantledegassing would be actually 'catastrophic' during geohistory and heterogeneous in dif-

Import of Rift Valley fever to China:a potential new threat?

Several recent studies in Virologica Sinica and other journals have highlighted the enormous international challenge of emerging arboviral diseases,such as Zika virus disease,dengue,and chikungunya(Islam et al.,2015;Maurice et al.,2015;Dai et al.,2016;Deng et al.,2016;Song et al.,2016;Wang et al.,2016;Xu et al.,2016;Zhang et al.,2016;Zhou

Efficacy of seed extracts of Annona squamosa and Annona muricata(Annonaceae) for the control of Aedes albopictus and Culex quinquefasciatus(Culicidae)

Objective:To evaluate the potential efficacy of seed extracts of Annona squamosa and Annona muricata used as natural insecticides to control adult and larvae of the vectors Aedes albopictus and Culex quinquefasciatus under laboratory conditions.Methods:Aqueous and oil extracts of the two plants were prepared from dried seeds.Preliminary identifications of the chemical components of each seed extracts were performed using microreactional and GCP techniques.Larvae and adults of Aedes albopictus and Culex quinquefasciatus were collected from the breeding sites in coastal and highlands regions of Madagascar.WHO standardized tests of susceptibility for larvae and imaginal stage of mosquitoes were realized to determine mortality and LC_(50) of mosquitoes.Results:Chemical identifications showed that these extracts contain alkaloids and flavonoids compounds that probably confer their biological insecticidal proprieties.CPG analysis showed also the presence of various fatty acids.On adult mosquitoes,significant insecticidal effects were observed with both aqueous and oil extracts of the two plant seeds compared to mortality induced by deltamethrin,an insecticide used as reference.Extracts of Annona muricata induced high mortality rate to both species of mosquito compared to extracts of Annona squamosa at all concentrations tested.The LC_(50) of seed extracts ranged from 1%to 5%for adults and 0.5%to 1%for larvae.Conclusions:The seed extracts of these two plants may be used as mosquito controlling agents and offer a new approach to a less costly,practical and environmentally friendly control of vector borne diseases.

Investigation of Spatial Risk Factors for RVF Disease Occurrence Using Remote Sensing &GIS—A Case Study: Sinnar State, Sudan

Rift Valley Fever (RVF) is an emerging, mosquito-borne disease with serious economical and negative implications on human and animal health. This study was conducted to verify the factors which influenced the spatial pattern of Rift Valley Fever occurrence and identified the high risk areas for the occurrence of the disease at Sinner State, Sudan. The normalized difference vegetation index (NDVI) derived from Moderate Resolution Imaging Spectroradiometer (MODIS) satellite and rainfall data in addition to the point data of RVF clinical cases in humans were used in this study. In order to identify the RVF high risk areas, remote sensing data and rainfall data were integrated in a GIS with other information including, soil type, water body, DEM (Digital Elevation Model), and animal routes and analyzed using Spatial Analysis tools. The information on clinical cases was used for verification. The Normalized Difference Vegetation Index (NDVI) was used to describe vegetation patterns of the study area by calculating the mean NDVI. The results of the study showed that, RVF risk increased with the increase in vegetation cover (high NDVI values), and increase in rainfall, which both provided suitable conditions for disease vectors breeding and a good indicator for RVF epizootics. The study concluded that, identification of high risk area for RVF disease improved the understanding of the spatial distribution of the disease and helped in locating the areas where disease was likely to be endemic and therefore preparedness measures should be taken. The identification represents the first step of prospective predictions of RVF outbreaks and provides a baseline for improved early warning, control, response planning, and mitigation. Further detailed studies are recommended in this domain.

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High Fluoride, Modest Fluorosis: Investigation in Drinking Water Supply in Halaba (SNNPR, Ethiopia)

In Halaba district in Southern Ethiopia fluoride levels from boreholes are high (2.6 to 7.0 mg/l), yet the incidence of fluorosis is modest. Drinking water users living in the vicinity of four drinking water systems that have been in operation for more than 35 years were surveyed. Out of 625 persons 5 percent had severe dental fluorosis and 42 percent had mild forms—which is considerably less than results of other areas with comparable fluoride levels. The incidence was highest in the older age groups. Possible explanations were explored. A likely reason may be the continued large dependence on rain water harvesting ponds for human consumption alongside the use of water from the public borehole systems, but more investigations would be required to confirm this proposition.