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Articles 71671 - 71700 of 294558

Full-Text Articles in Physical Sciences and Mathematics

Effect Of Ph And Heat Treatment On Physicochemical And Functional Properties Of Spray-Dried Whey Protein Concentrate Powder, Thao M. Ho, Jinlei Zhu, Nidhi Bansal, Mary C. Boyce, Thao T. Le Aug 2021

Effect Of Ph And Heat Treatment On Physicochemical And Functional Properties Of Spray-Dried Whey Protein Concentrate Powder, Thao M. Ho, Jinlei Zhu, Nidhi Bansal, Mary C. Boyce, Thao T. Le

Research outputs 2014 to 2021

Effects of pH and heating on deamidation of whey protein concentrate (WPC) solution and functional properties of resultant spray-dried WPC powder were investigated. Temperature and heating time affected deamidation rates with the highest reactivities for WPC solutions heated at 120 °C for 15 min and 145 °C for 120 s. Deamidation sites were pH dependent: pH 3 induced more glutamine deamidation; pH 10 induced more asparagine deamidation. The functional properties of spray-dried WPC powders were also pH dependent. WPC solution adjusted to pH 3 and heated at 145 °C for 120 s (prior to spray drying) exhibited a reduction in …

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10577063 Edd, Pioneer Technical Services, Inc. Aug 2021

10577063 Edd, Pioneer Technical Services, Inc.

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

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Bayesian Sensitivity-Specificity And Roc Analysis For Finding Key Drivers, Stan Lipovetsky, Michael W. Conklin Aug 2021

Bayesian Sensitivity-Specificity And Roc Analysis For Finding Key Drivers, Stan Lipovetsky, Michael W. Conklin

Journal of Modern Applied Statistical Methods

Finding key drivers in regression modeling via Bayesian Sensitivity-Specificity and Receiver Operating Characteristic is suggested, and clearly interpretable results are obtained. Numerical comparisons with other techniques show that this methodology can be useful in practical statistical modeling and analysis helping to researchers and managers in making meaningful decisions.

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Recurrent Pattern Of Extreme Fire Weather In California, Rackhun Son, S-Y Simon Wang, Seung Hee Kim, Hyungjun Kim, Jee-Hoon Jeong, Jin-Ho Yoon Aug 2021

Recurrent Pattern Of Extreme Fire Weather In California, Rackhun Son, S-Y Simon Wang, Seung Hee Kim, Hyungjun Kim, Jee-Hoon Jeong, Jin-Ho Yoon

Mathematics, Physics, and Computer Science Faculty Articles and Research

Historical wildfire events in California have shown a tendency to occur every five to seven years with a rapidly increasing tendency in recent decades. This oscillation is evident in multiple historical climate records, some more than a century long, and appears to be continuing. Analysis shows that this 5–7 year oscillation is linked to a sequence of anomalous large-scale climate patterns with an eastward propagation in both the ocean and atmosphere. While warmer temperature emerges from the northern central Pacific to the west coast of California, La Niña pattern develops simultaneously, implying that the lifecycle of the El Niño-Southern Oscillation …

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Rhyolite Stratigraphy Along Succor Creek: Insights Into The Eruptive History Of The Three Fingers And Mahogany Mountain Volcanic Field, Cassandra Caryl Black Aug 2021

Rhyolite Stratigraphy Along Succor Creek: Insights Into The Eruptive History Of The Three Fingers And Mahogany Mountain Volcanic Field, Cassandra Caryl Black

Dissertations and Theses

The Mahogany Mountain and Three Fingers calderas with their associated tuffs, the tuff of Leslie Gulch and tuff of Spring Creek, respectively, were the centerpiece of a larger rhyolite center that developed in response to Columbia River Basalt volcanism as numerous other mid Miocene rhyolite centers in a corridor from Baker City in the north to northern Nevada. Previous studies suggest a two caldera model, while others advocated for a single large caldera producing solely the tuff of Leslie Gulch. This study refines the eruptive stratigraphy along the northeastern margin of this rhyolite field with important implications for the entire …

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Investigation Of Environmental-Friendly, Membraneless Hydrogen Peroxide Fuel Cells, Bao Nguyen Aug 2021

Investigation Of Environmental-Friendly, Membraneless Hydrogen Peroxide Fuel Cells, Bao Nguyen

Dissertations and Theses

Human-induced climate change is one of the biggest threats to humanity in the 21st century. This is caused by the increase in greenhouse gas concentrations in the Earth's atmosphere. The burning of fossil fuels is the primary cause of climate change. This problem can be addressed by replacing fossil fuels with fuel sources that have clean by-products and are cost-effective. For the last few decades, hydrogen (H2) has been extensively studied as an alternative to carbon-based fossil fuels. Currently, H2 still has many shortcomings for commercial applications. The photocatalytic production of H2 still suffers from …

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Approximate Solutions Of Nonlinear Partial Differential Equations Using B-Polynomial Bases, Muhammad I. Bhatti, Md. Habibur Rahman, Nicholas Dimakis Aug 2021

Approximate Solutions Of Nonlinear Partial Differential Equations Using B-Polynomial Bases, Muhammad I. Bhatti, Md. Habibur Rahman, Nicholas Dimakis

Physics & Astronomy Faculty Publications

A multivariable technique has been incorporated for guesstimating solutions of Nonlinear Partial Differential Equations (NPDE) using bases set of B-Polynomials (B-polys). To approximate the anticipated solution of the NPD equation, a linear product of variable coefficients ai(t) and Bi(x) B-polys has been employed. Additionally, the variable quantities in the anticipated solution are determined using the Galerkin method for minimizing errors. Before the minimization process is to take place, the NPDE is converted into an operational matrix equation which, when inverted, yields values of the undefined coefficients in the expected solution. The nonlinear terms of the NPDE are combined in the …

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From River To Sea: Improving Carbon System Measurement Methods For Use In Rivers, Estuaries, And Oceans, Ellie Hudson-Heck Aug 2021

From River To Sea: Improving Carbon System Measurement Methods For Use In Rivers, Estuaries, And Oceans, Ellie Hudson-Heck

USF Tampa Graduate Theses and Dissertations

Over the last 30 years, spectrophotometric methodologies have been developed, with increasing rigor, to accurately measure all four carbon system parameters: total alkalinity (AT), total carbon (CT), partial pressure of CO2 (pCO2), and pH. Spectrophotometric measurements of carbon system parameters rely on quantitative characterizations of the response of sulfonephthalein indicator dyes (e.g., meta-cresol purple (mCP), thymol blue (TB), and bromocresol purple (BCP)) to changing solution pH, as well the response of indicator physical-chemical characteristics to key environmental variables (salinity (SP), temperature (T), and pressure). Until recently, the physical-chemical properties …

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Continental-Scale Network Reveals Cross-Jurisdictional Movements Of Sympatric Sharks With Implications For Assessment And Management, Charlie Huveneers, Yuri Niella, Michael Drew, Rory Mcauley, Paul A. Butcher, Victor Peddemors, Daniela Waltrick, Chris Dowling, Silas Mountford, Ian S. Keay, Matias Braccini Aug 2021

Continental-Scale Network Reveals Cross-Jurisdictional Movements Of Sympatric Sharks With Implications For Assessment And Management, Charlie Huveneers, Yuri Niella, Michael Drew, Rory Mcauley, Paul A. Butcher, Victor Peddemors, Daniela Waltrick, Chris Dowling, Silas Mountford, Ian S. Keay, Matias Braccini

Fisheries Research Articles

Understanding the movement ecology of marine species and connectivity of populations is required for effective fisheries management. This is especially the case for species with wide-ranging distributions for which movement can span across several jurisdictions with different management regulations. We used the Australian national network of acoustic receivers facilitated by the Integrated Marine Observing System (IMOS) to describe the extent and frequency of movements for two large epipelagic shark species, the bronze whaler (Carcharhinus brachyurus) and dusky shark (Carcharhinus obscurus). A total of 210 sharks (117 bronze whalers and 93 dusky sharks) were tracked for a …

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Is Australia Really Lost In Space?, Brett Biddington Aug 2021

Is Australia Really Lost In Space?, Brett Biddington

Research outputs 2014 to 2021

Australia is one of the world's most wealthy nations. Yet to the surprise and puzzlement of many observers, Australian governments over many years steadfastly refused to become involved in space activities in ways judged to be commensurate to the nation's wealth and place in the world. Repeated calls to establish a space agency were ignored or firmly rejected and civil and commercial investment in space activities was limited. In the past decade, there have been substantial developments and new investments in the policy, national security, civil and commercial domains. Perhaps the salient feature is the establishment of the Australian Space …

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Unintended Consequences Of Air Cleaning Chemistry, Douglas B. Collins, Delphine K. Farmer Aug 2021

Unintended Consequences Of Air Cleaning Chemistry, Douglas B. Collins, Delphine K. Farmer

Faculty Journal Articles

Amplified interest in maintaining clean indoor air associated with the airborne transmission risks of SARS-CoV-2 have led to an expansion in the market for commercially available air cleaning systems. While the optimal way to mitigate indoor air pollutants or contaminants is to control (remove) the source, air cleaners are a tool for use when absolute source control is not possible. Interventions for indoor air quality management include physical removal of pollutants through ventilation or collection on filters and sorbent materials, along with chemically reactive processes that transform pollutants or seek to deactivate biological entities. This perspective intends to highlight the …

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Accelerating The Provision Of Safe Water Supply In Urban And Rural Areas Of Indonesia, Sumengen Sutomo, Salord Sagala, Bebi Sutomo, Sri Winarti, Gelant Sanjaya Aug 2021

Accelerating The Provision Of Safe Water Supply In Urban And Rural Areas Of Indonesia, Sumengen Sutomo, Salord Sagala, Bebi Sutomo, Sri Winarti, Gelant Sanjaya

Kesmas

Over the past 100 years, the provision of a safe water supply to drink in Indonesia has been slowly progressed with low coverage. The majority of the population does not have access to safe water. Morbidity and mortality of water-related diseases, including diarrhea, are very high. The provision of safe water is not a technological issue but good water management that comprises content, institutional, and communication layer. This paper provided information for strategic and operational decisions to accelerate the provision of safe water services in urban and rural areas. Benchmarking good water management with the characteristics of the water supply …

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Association Between Self-Reported Fatigue And Sarcopenia Measures Among Elderly In Selangor, Malaysia, Maria Justine, Aliff Latir, Nadhirah Noor, Angelbeth Joanny, Izzaty Iskandar, Maisarah Sakinah Amirul Faizi, Dzulhelmi Edinan Aug 2021

Association Between Self-Reported Fatigue And Sarcopenia Measures Among Elderly In Selangor, Malaysia, Maria Justine, Aliff Latir, Nadhirah Noor, Angelbeth Joanny, Izzaty Iskandar, Maisarah Sakinah Amirul Faizi, Dzulhelmi Edinan

Kesmas

The association between fatigue and sarcopenia is not well understood, therefore, this study aimed to compare the sarcopenia measures among elderly with mild and severe fatigue and to determine whether fatigue severity is associated with sarcopenia measures. This was a cross-sectional study conducted on201 elderly (age = 68.45±6.30 years). The elderly was classified into either mild or severe fatigue based on the Fatigue Severity Scale (FSS), meanwhile, sarcopenia measures include SARC-F score, muscle mass (ASM/height2), calf circumference (CC), upper (handgrip) and lower limb muscle strength, as well as physical performance (gait speed). Data were analyzed using independent t-tests and logistic …

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Ocean Regime Shift Is Driving Collapse Of The North Atlantic Right Whale Population, Erin L. Meyer-Gutbrod, Charles H. Greene, Kimberley T.A. Davies, David G. Johns Aug 2021

Ocean Regime Shift Is Driving Collapse Of The North Atlantic Right Whale Population, Erin L. Meyer-Gutbrod, Charles H. Greene, Kimberley T.A. Davies, David G. Johns

Faculty Publications

Ocean warming linked to anthropogenic climate change is impacting the ecology of marine species around the world. In 2010, the Gulf of Maine and Scotian Shelf regions of the Northwest Atlantic underwent an unprecedented regime shift. Forced by climate-driven changes in the Gulf Stream, warm slope waters entered the region and created a less favorable foraging environment for the endangered North Atlantic right whale population. By mid-decade, right whales had shifted their late spring/summer foraging grounds from the Gulf of Maine and the western Scotian Shelf to the Gulf of St. Lawrence. The population also began exhibiting unusually high …

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In Vivo Antidiabetic Activities Of Polyherbal Extracts Against Streptozotocin-Nicotinamide Induced Type 2 Diabetic Mice Model, Pradnya Jagtap, Yashashri Nimbalkar, Vidya Patil, Ravindra Y. Patil Aug 2021

In Vivo Antidiabetic Activities Of Polyherbal Extracts Against Streptozotocin-Nicotinamide Induced Type 2 Diabetic Mice Model, Pradnya Jagtap, Yashashri Nimbalkar, Vidya Patil, Ravindra Y. Patil

Tanzania Journal of Science

Diabetes mellitus is a chronic metabolic disorder and rapidly increasing cases of diabetes throughout the world are major concerns in both developed and developing countries. Currently available oral antidiabetic medicines have limitations in efficacy and safety, which in conjunction with the emergence of diabetes mellitus as a global epidemic have aided the popularity of alternative therapies to manage the disease safely and more efficiently. Herbal medicines are accepted as alternative therapies for blood sugar control. Gymnema sylvestre, Boerhavia diffusa, Tinospora cordifolia, and Argyreia nervosa are some potent herbs used for the management of diabetes. Mixing of these plants in different …

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An Age-Structured Model For Transmission Dynamics Of Malaria With Infected Immigrants And Asymptomatic Carriers, Asha S Kalula, Eunice Mureithi, Theresia Marijani, Isambi Mbalawata Aug 2021

An Age-Structured Model For Transmission Dynamics Of Malaria With Infected Immigrants And Asymptomatic Carriers, Asha S Kalula, Eunice Mureithi, Theresia Marijani, Isambi Mbalawata

Tanzania Journal of Science

Abstract An age-structured (children and adults) model for the transmission dynamics of malaria with asymptomatic carriers and infected immigrants has been analyzed. We first analyze a model without infected immigrants. It shows that the disease-free equilibrium exists and is stable when and unstable for . Also, we compute the sensitivity indices of the basic reproduction number. The basic reproduction number is most sensitive to the mosquito biting rate. Besides, the sensitivity of the basic reproduction number shows that the children's class parameters are more sensitive than those of adults. In the presence of infected immigrants, the model does not admit …

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Mathematical Programming Model For The Two-Level Facility Location Problem: The Case Of Tanzanian Emergence Maize Distribution Network For 2004–2010 Maize Data, Said A. Sima Aug 2021

Mathematical Programming Model For The Two-Level Facility Location Problem: The Case Of Tanzanian Emergence Maize Distribution Network For 2004–2010 Maize Data, Said A. Sima

Tanzania Journal of Science

A two-level facility location problem (FLP) has been studied in the transportation network of emergence maize crop in Tanzania. The facility location problem is defined as the optimal location of facilities or resources so as to minimize costs in terms of money, time, distance and risks with the relation to supply and demand points. Distribution network design problems consist of determining the best way to transfer goods from the supply to the demand points by choosing the structure of the network such that the overall cost is minimized. The three layers, namely production centres (PCs), distribution centres (DCs) and customer …

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Stocking Density, Growth And Survival Rate Of Post-Settled Juveniles Of Holothuria Scabra (Jaeger 1833) Reared In An Ocean-Based Floating Hapa, Yussuf S Yussuf, Saleh As Yahya Aug 2021

Stocking Density, Growth And Survival Rate Of Post-Settled Juveniles Of Holothuria Scabra (Jaeger 1833) Reared In An Ocean-Based Floating Hapa, Yussuf S Yussuf, Saleh As Yahya

Tanzania Journal of Science

Ocean-based nursery system using floating hapa have proved to be the best option for raising early sandfish juveniles. However, the nursery system can be further improved by providing key information that will support their application. The present study provides information on the effect of stocking density on growth and survival of sandfish juveniles reared in floating hapa (1 x 0.5 x 1 m). Three densities were tested, 100, 200 and 400 early juveniles (5 mm; 0.093 g) per hapa net in a randomized set-up. Initial density of 100 and 200 showed significant higher growth rate and final size (0.082–0.074 g/day; …

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Josephson Effect In Mgb2/Pd/Nb Trilayer Josephson Junctions, Anayesu B Malisa Aug 2021

Josephson Effect In Mgb2/Pd/Nb Trilayer Josephson Junctions, Anayesu B Malisa

Tanzania Journal of Science

This paper reports fabrication techniques and results of MgB2/Pd/Nb trilayer Josephson junctions. The MgB2 bottom electrode was co-evaporated by molecular beam epitaxy (MBE) technique from both magnesium and boron sources at a low substrate temperature ~ 300 °C, while the interlayer and the top niobium electrode (Pd/Nb bilayer) were deposited ex-situ using RF sputtering. The junctions exhibited  and  Josephson effect as well as a modulation of the critical current in a magnetic field applied in a direction normal to the junction plane. Fractional and integer Shapiro steps were observed at voltages corresponding to the frequency of the applied microwave radiation …

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Mollusc Shells From Neolithic Contexts In The Lake Eyasi Basin, Northern Tanzania, Musa S. Mwitondi, Albert S. Mjandwa, Pastory M. Bushozi Aug 2021

Mollusc Shells From Neolithic Contexts In The Lake Eyasi Basin, Northern Tanzania, Musa S. Mwitondi, Albert S. Mjandwa, Pastory M. Bushozi

Tanzania Journal of Science

The study of the Neolithic period in the Lake Eyasi Basin was dominated by attempts to formulate the area’s chronology, mobility, settlement patterns, subsistence, and cultural capabilities of Neolithic people as attested by domesticated animals, pottery, and lithic artefacts. Occasionally, studies on molluscs were mentioned, but rarely described in detail. Neolithic sites across the Lake Eyasi Basin have yielded remains of both terrestrial (gastropods) and freshwater mollusc shells (mussels). The abundance of mollusc shell remains in the archaeological records of the Lake Eyasi Basin have played a great role in chronological settings, mobility and community integrations, studies of settlement patterns, …

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Maintenance Automation Architecture And Electrical Equipment Fault Prediction Method In Tanzania Secondary Distribution Networks, Hadija Mbembati, Kwame Ibwe, Baraka Maiseli Aug 2021

Maintenance Automation Architecture And Electrical Equipment Fault Prediction Method In Tanzania Secondary Distribution Networks, Hadija Mbembati, Kwame Ibwe, Baraka Maiseli

Tanzania Journal of Science

Distribution networks remain the most maintenance-intensive parts of power systems. The implementation of maintenance automation and prediction of equipment fault can enhance system reliability while reducing the overall costs. In Tanzania, however, maintenance automation has not been deployed in secondary distribution networks (SDNs). Instead, traditional methods are used for condition prediction and fault identification of power assets (transformers and power lines). These (manual) methods are costly and time-consuming, and may introduce human-related errors. Motivated by these challenges, this work introduces maintenance automation into the network architecture by implementing effective maintenance and fault identification methods. The proposed method adopts machine learning …

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High Speed Hill Climbing Algorithm For Portfolio Optimization, Collether John Aug 2021

High Speed Hill Climbing Algorithm For Portfolio Optimization, Collether John

Tanzania Journal of Science

Portfolio can be defined as a collection of investments. Portfolio optimization usually is about maximizing expected return and/or minimising risk of a portfolio. The mean-variance model makes simplifying assumptions to solve portfolio optimization problem. Presence of realistic constraints leads to a significant different and complex problem. Also, the optimal solution under realistic constraints cannot always be derived from the solution for the frictionless market. The heuristic algorithms are alternative approaches to solve the extended problem. In this research, a heuristic algorithm is presented and improved for higher efficiency and speed. It is a hill climbing algorithm to tackle the extended …

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Synthesis Of 1-(2,4-Dinitrophenyl)-3,5-Diphenyl-1h-Pyrazol-4-Ol Via Trans-1,3-Diphenyl-2,3-Epoxy-1-Propanone, Oluwaseyi B Ovonramwen Aug 2021

Synthesis Of 1-(2,4-Dinitrophenyl)-3,5-Diphenyl-1h-Pyrazol-4-Ol Via Trans-1,3-Diphenyl-2,3-Epoxy-1-Propanone, Oluwaseyi B Ovonramwen

Tanzania Journal of Science

The trans-1,3-diphenyl-2,3-epoxy-1-propanone was synthesized from benzaldehyde and 2-bromoacetophenone in 20 min which is more economical. The presence of ethanol and Br in 2-bromoacetophenone facilitated the reaction. The vicinal diaxial coupling constant of trans-1,3-diphenyl-2,3-epoxy-1-propanone was zero, an indication of trans configuration for a rigid 3-membered ring at ~90o dihedral angle. 1-(2,4-Dinitrophenyl)-3,5-diphenyl-1H-pyrazol-4-ol was synthesized from trans-1,3-diphenyl-2,3-epoxy-1-propanone and 2,4-dinitro phenylhydrazine in glacial CH3COOH to give 85.5% yield and characterized using FTIR, 1H, 13C NMR, DEPT 135 and MS spectra. The 1-(2,4-dinitrophenyl)-3,5-diphenyl-1H-pyrazol-4-ol can be exploited for unique biological activities and in the synthesis of synthetic fibers. Keywords:    1-(2,4-dinitrophenyl)-3,5-diphenyl-1H-pyrazol-4-ol, trans-1,3-diphenyl-2,3-epoxy-1-propanone, synthesis, 2,4-dinitro phenylhydrazine.

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Effects Of Climate Changes On Water Resources: A Case Of Mindu Dam In Morogoro Municipality, Tanzania, Simon R Melchioly Aug 2021

Effects Of Climate Changes On Water Resources: A Case Of Mindu Dam In Morogoro Municipality, Tanzania, Simon R Melchioly

Tanzania Journal of Science

This paper presents the findings of the research conducted in Morogoro Municipality, central Tanzania. The main objective of the research was to assess the climate change impacts on water resources, taking the Mindu Dam as the case study. The study methodology involved collection, processing and analysis of both primary and secondary data. Data collection involved acquisition of Dam water level data, climate data, and Landsat 8 satellite imagery. Research findings showed that the maximum air temperature increased at a rate of 0.045% on a span of 30 years, while rainfall has been decreasing with time. Also there has been a …

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Spatial Modelling For Cholera Incidence Rates In Morogoro Municipality, Tanzania, Caroline Ngereza, Rosalia S. Katapa, Ali R. Mniachi Aug 2021

Spatial Modelling For Cholera Incidence Rates In Morogoro Municipality, Tanzania, Caroline Ngereza, Rosalia S. Katapa, Ali R. Mniachi

Tanzania Journal of Science

Spatial modelling was conducted to examine community factors associated with cholera incidence rates in Morogoro Municipality. The study employed both secondary (cholera cases) and primary (geographic coordinates of community risk factors) data. Spatial lag model was applied in examining association between the variables. All wards of Morogoro Municipality were considered in the study to capture their variations because cholera cases have a tendency to be clustered. Results indicated that market density, distance to the market and distance to the dumpster are significant factors associated with cholera incidence rates in the wards (p < 0.05). Geographically weighted Poisson model was used to show the variations of those factors between the wards in Municipality. A statistically significant positive association of cholera incidence rates; and market density was only found in Mazimbu ward (p < 0.05) and distance from the community to the dumpster was found in Kihonda, Kingolwira, Bigwa, Kichangani, Kilakala and Boma wards (p < 0.001) and some wards at the centre of the municipality which are Mji Mkuu and Kingo (p < 0.05). A statistically significant negative association of cholera incidence rates and distance from the centre of the community to the market was found in Kihonda, Kingolwira and Kichangani (p < 0.001) and Bigwa wards (p < 0.05). Therefore, measures taken to control and prevent cholera disease should base on the variations of the risk factors found in the Municipal wards.  Keywords:    Cholera incidence rate, Spatial lag regression model, Community risk factor, Geographically weighted Poisson model

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Physicochemical And Bacteriological Water Quality Parameters In Relation To Land-Use Practices At A Rural Catchment, Mbinga District, Tanzania, Harieth Hellar-Kihampa, Patrick Isdory Ndunguru Aug 2021

Physicochemical And Bacteriological Water Quality Parameters In Relation To Land-Use Practices At A Rural Catchment, Mbinga District, Tanzania, Harieth Hellar-Kihampa, Patrick Isdory Ndunguru

Tanzania Journal of Science

Data on physicochemical water quality parameters and contamination levels is crucial for protection and sustainable utilization of water resources. This study assessed the physicochemical water quality parameters, faecal coliform bacteria and nutrient loads in water at a catchment used for municipal supply in Mbinga District, Tanzania. Samples were seasonally collected from three areas characterized by distinct geographical features, settlement patterns and land-use practices, and analyzed using standard analytical protocols. Data were subjected to paired-sampled t-test and cluster analysis. The parameters varied as follows: pH (4.75–6.83); temperature (16.4–26.2 ºC); electrical conductivity (14.6–121.1 µS/cm); total dissolved solids (7.0–23.2 mg/L); total suspended solids …

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Assessment Of Groundwater Quality In Areas Surrounding Thundulu Phosphate Mine, Phalombe District, Malawi, Philip Jailos, Peter J. Chimtali, Ephraim Vunain Aug 2021

Assessment Of Groundwater Quality In Areas Surrounding Thundulu Phosphate Mine, Phalombe District, Malawi, Philip Jailos, Peter J. Chimtali, Ephraim Vunain

Tanzania Journal of Science

Water is one of the renewable resources essential for sustaining all forms of life and quality of drinking water is very fundamental for human health. Human activities such as mining act as sources of water contamination which consequently lead to ecological, environmental and health problems. To the best of our knowledge, no study has been conducted around the Thundulu Phosphate Mine to establish the quality of drinking water. In this regard, this study was carried out to evaluate the physico-chemical water quality parameters of areas surrounding the Thundulu Phosphate Mine in Phalombe District. Groundwater samples from the villages surrounding the …

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Potency Of Dioscorea Sansibarensis (Dioscoreaceae) Leaf Eluates On Callosobruchus Chinensis, Linnaeus 1758 (Coleoptera: Bruchidae) In The Protection Of Phaseolus Vulgaris (Fabaceae), Godfrey O. Mauti Aug 2021

Potency Of Dioscorea Sansibarensis (Dioscoreaceae) Leaf Eluates On Callosobruchus Chinensis, Linnaeus 1758 (Coleoptera: Bruchidae) In The Protection Of Phaseolus Vulgaris (Fabaceae), Godfrey O. Mauti

Tanzania Journal of Science

Post-harvest losses of stored Phaseolus vulgaris to the bean weevil Callosobruchus chinensis have reached levels of significant concern. Governments and health organisations propose the discovery of reliable,  healthy and biodegradable pesticides with higher selectivity and a broad spectrum. This study presents investigations on the activities of Dioscorea sansibarensis leaf extracts on the mortality of C. chinensis and reduction of their egg-laying ability. Laboratory experiments under Completely Randomized Design (CRD) were carried out to determine the mortality and anti-oviposition activity of the vacuum liquid chromatography (VLC) eluates of n-hexane (HE), chloroform (CE), ethyl acetate (EE), n-butanol (BE) and methanol (BE) at …

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Determination Of Quantile Range Of Optimal Hyperparameters Using Bayesian Estimation, Ayoade I. Adewole, Olusoga A. Fasoranbaku Aug 2021

Determination Of Quantile Range Of Optimal Hyperparameters Using Bayesian Estimation, Ayoade I. Adewole, Olusoga A. Fasoranbaku

Tanzania Journal of Science

Bayesian estimations have the advantages of taking into account the uncertainty of all parameter estimates which allows virtually the use of vague priors. This study focused on determining the quantile range at which optimal hyperparameter of normally distributed data with vague information could be obtained in Bayesian estimation of linear regression models. A Monte Carlo simulation approach was used to generate a sample size of 200 data-set. Observation precisions and posterior precisions were estimated from the regression output to determine the posterior means estimate for each model to derive the new dependent variables. The variances were divided into 10 equal …

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Assessment Of Farm Households’ Vulnerability To Desertification In Rural Dry Lands Of Katsina State, Nigeria, Olanrewaju Yusuf Yahaya Aug 2021

Assessment Of Farm Households’ Vulnerability To Desertification In Rural Dry Lands Of Katsina State, Nigeria, Olanrewaju Yusuf Yahaya

Tanzania Journal of Science

The purpose of this study was to use a Vulnerability Index (VI) to assess farm households' vulnerability to desertification in Northern Katsina's dry land ecosystem. The specific objectives were to identify socio-economic characteristics of farm households; and determine the degree of their vulnerability to desertification. A systematic random sampling technique was used to select 633 respondents from 18 rural communities across six Local Government Areas (LGAs). Data from 21 indicators for the three components of vulnerability (exposure, sensitivity and adaptive capacity) were used to measure the degree of vulnerability and thus, classify households into less, moderate and highly vulnerable. The …

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