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Search Results: 1 - 10 of 400787 matches for " Philbert M. Luhunga "
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Homogeneity of Monthly Mean Air Temperature of the United Republic of Tanzania with HOMER  [PDF]
Philbert M. Luhunga, Edmund Mutayoba, Hashim K. Ng’ongolo
Atmospheric and Climate Sciences (ACS) , 2014, DOI: 10.4236/acs.2014.41010
Abstract:

The long-term climate datasets are widely used in a variety of climate analyses. These datasets, however, have been adversely impacted by inhomogeneities caused by, for example relocations of meteorological station, change of land use cover surrounding the weather stations, substitution of meteorological station, changes of shelters, changes of instrumentation due to its failure or damage, and change of observation hours. If these inhomogeneities are not detected and adjusted properly, the results of climate analyses using these data can be erroneous. In this paper for the first time, monthly mean air temperatures of the United Republic of Tanzania are homogenized by using HOMER software package. This software is one of the most recent homogenization software and exhibited the best results in the comparative analysis performed within the COST Action ES0601 (HOME). Monthly mean minimum (TN) and maximum (TX) air temperatures from 1974 to 2012 were used in the analysis. These datasets were obtained from Tanzania Meteorological Agency (TMA). The analysis reveals a larger number of artificial break points in TX (12 breaks) than TN (5 breaks) time series. The homogenization process was assessed by comparing results obtained with Correlation analysis and Principal Component analysis (PCA) of homogenized and non-homogenized datasets. Mann-Kendal non-parametric test was used to estimate the existence, magnitude and statistical significance of potential trends in the homogenized and non-homogenized time series. Correlation analysis reveals stronger correlation in homogenized TX than TN in relation to non-homogenized time series. Results from PCA suggest that the explained variances of the principal components are higher in homogenized TX than TN in relation to non-homogenized time series. Mann-Kendal non-parametric test reveals that the number of statistical significant trend increases

Evaluation of the Performance of ENACTS MAP-ROOM Products over Tanzania  [PDF]
Philbert M. Luhunga, Agnes L. Kijazi, Ladislaus Chang’a, Hashim Ng’ongolo, Alfred Kondowe
Atmospheric and Climate Sciences (ACS) , 2019, DOI: 10.4236/acs.2019.92014
Abstract: Tanzania has inadequate weather stations (28-synoptic weather stations), which are sparsely distributed over complex topographic terrain. Many places, especially rural areas, have no stations to monitor weather and climate. In this study, we evaluate the performance of ENACT-MAPROOM products over Tanzania with the aim of assessing their potential to supplement observed weather and climate data, especially over areas where there is limited number of weather stations. Monthly rainfall total and monthly averaged minimum and maximum temperatures from ENACT-MAPROOM are evaluated against observed data from 23 weather stations. The evaluation is limited to analyze how well the ENACT-MAPROOM products reproduce climatological trends, annual cycles and inter-annual variability of rainfall, minimum and maximum temperatures. Statistical analysis recommended by the World Meteorological Organization (WMO) that includes that correlation and trend analysis are used. It is found that ENACT-MAPROOM products reproduce the climatological trends, annual cycles and inter-annual variability of rainfall, minimum and maximum temperatures over most stations. The statistical relationship between ENACT-MAPROOM products against observed data from 23 weather stations using Pearson correlation coefficient indicates that ENACT-MAPROOM products bear strong and statistically significant correlation coefficient to observed data. The overall evaluation here finds high skills of ENACT-MAPROOM products in representing rainfall and temperature over Tanzania, suggesting their potential use in planning and decision making especially over areas with limited number of weather stations.
Spatial and Temporal Analysis of Rainfall and Temperature Extreme Indices in Tanzania  [PDF]
Ladislaus B. Chang’a, Agnes L. Kijazi, Philbert M. Luhunga, Hashim K. Ng’ongolo, Habiba I. Mtongor
Atmospheric and Climate Sciences (ACS) , 2017, DOI: 10.4236/acs.2017.74038
Abstract: Climate extreme indices in Tanzania for the period 1961-2015 are analyzed us-ing quality controlled daily rainfall, maximum and minimum temperatures data. RClimdex and National Climate Monitoring Products (NCMP) software developed by the commission for climatology of the World Meteorological Organization (WMO) were used for the computation of the indices at the respective stations at monthly and annual time scales. The trends of the extreme indices averaged over the country were computed and tested for statistical significance. Results showed a widespread statistical significant increase in temperature extremes consistent with global warming patterns. On average, the annual timescale indicate that mean temperature anomaly has increased by 0.69°C, mean percentage of warm days has increased by 9.37%, and mean percentage of warm nights has increased by 12.05%. Mean percentage of cold days and nights have decreased by 7.64% and 10.00% respectively. A non-statistical significance decreasing trends in rainfall is depicted in large parts of the country. Increasing trend in percentage of warm days and warm nights is mostly depicted over the eastern parts of the country including areas around Kilimanjaro, Dar-es-Salaam, Zanzibar, Mtwara, and Mbeya regions. Some parts of the Lake Victoria Basin are also characterized by increasing trend of warm days and warm nights. However, non-statistical significant decreasing trends in the percentage of warm days and warm nights are depicted in the western parts of the country including Tabora and Kigoma regions and western side of the lake Victoria. These results indicate a clear dipole pattern in temperature dynamics between the eastern side of the country mainly influenced by the Indian Ocean and the western side of the country largely influenced by the moist Congo air mass associated with westerly winds. The results also indicate that days and nights are both getting warmer, though, the warming trend is much faster in the minimum temperature than maximum temperature.
Moist Potential Vorticity Vector for Diagnosis of Heavy Rainfall Events in Tanzania  [PDF]
Philbert Modest Luhunga, George Djolov, Edmund Mutayoba
Journal of Geoscience and Environment Protection (GEP) , 2016, DOI: 10.4236/gep.2016.49010
Abstract: In this paper, we modify the convective vorticity vector (CVV) defined as a cross product of absolute vorticity and gradient of equivalent potential temperature to moist potential vorticity vector (MPVV) defined as a cross product of absolute vorticity (\"\") and the gradient of the moist-air entropy potential temperature (\"\").? The patterns of (MPVV) are compared with the patterns of heavy rainfall events that occurred over different regions in Tanzania on 20th to 22nd December, 2011 and on 5th to 8th May, 2015. Moreover, the article aimed at assessing the relative contributions of the magnitude, horizontal and vertical components of (MPVV) detecting on the observed patterns of rainfall events. Dynamic and thermodynamic variables: wind speed, temperature, atmospheric pressure and relative humidity from numerical output generated by the Weather Research and Forecasting (WRF) model running at Tanzania Meteorological Agency (TMA) were used to compute MPVV. It is found that MPVV provide accurate tracking of locations received heavy rainfall, suggesting its potential use as a dynamic tracer for heavy rainfall events in Tanzania.? Finally it is found that the first and second components of MPVV contribute almost equally in tracing locations received heavy rainfall events. The magnitude of MPVV described the locations received heavy rainfall events better than the components.
A Review of Agricultural Pesticides Use and the Selection for Resistance to Insecticides in Malaria Vectors  [PDF]
Anitha Philbert, Sylvester Leonard Lyantagaye, Gamba Nkwengulila
Advances in Entomology (AE) , 2014, DOI: 10.4236/ae.2014.23019
Abstract: Most national malaria control programmes rely extensively on pyrethroid insecticides to control mosquito vectors of this disease. Unfortunately, the intensive use of this class of insecticides both in public health and agriculture has led to its reduced efficacy. The objective of this review was to assess the role of agricultural pesticides use on the development of resistance to insecticides in malaria vectors and the potential impact of this resistance on control activities. We searched library catalogues and public databases for studies that included data on resistance to the major classes of insecticides: organochlorines, carbamates, organophosphates and pyrethroids, in the malaria vectors of Anopheles genera. There is a strong geographical bias in published studies many originating from West African countries. Several studies demonstrate that resistance to pyrethroids is widespread in the major malaria vectors of the Anopheles gambiae and Anopheles funestus complexes. Assessing the impact of insecticide resistance on vector control is complicated owing to the lack of studies into the epidemiological consequences of resistance on the control of malaria and other vector borne diseases.
Schistosomiasis transmission at high altitude crater lakes in Western Uganda
Rubaihayo John, Moghusu Ezekiel, Clouds Philbert, Abaasa Andrew
BMC Infectious Diseases , 2008, DOI: 10.1186/1471-2334-8-110
Abstract: An epidemiological survey of intestinal schistosomiasis was carried out in school children staying around 13 high altitude crater lakes in Western Uganda. Stool samples were collected and then processed with the Kato-Katz technique using 42 mg templates. Thereafter schistosome eggs were counted under a microscope and eggs per gram (epg) of stool calculated. A semi-structured questionnaire was used to obtain demographic data and information on risk factors.36.7% of the pupils studied used crater lakes as the main source of domestic water and the crater lakes studied were at altitude ranging from 1487–1682 m above sea level. 84.6% of the crater lakes studied were infective with over 50% of the users infected.The overall prevalence of Schistosoma mansoni infection was 27.8% (103/370) with stool egg load ranging from 24–6048 per gram of stool. 84.3%( 312) had light infections (<100 eggs/gm of stool), 10.8%( 40) had moderate infections (100–400 eggs/gm of stool) and 4.9% (18) had heavy infections (>400 egg/gm of stool). Prevalence was highest in the age group 12–14 years (49.5%) and geometric mean intensity was highest in the age group 9–11 years (238 epg). The prevalence and geometric mean intensity of infection among girls was lower (26%; 290 epg) compared to that of boys (29.6%; 463 epg) (t = 4.383, p < 0.05). Though 61%(225) of the pupils interviewed were aware of the existence of the disease, 78% (290)didn't know the mode of transmission and only 8% (30) of those found infected were aware of their infection status. In a multivariate logistic regression model, altitude and water source (crater lakes) were significantly associated with infection.The altitudinal threshold for S. mansoni transmission in Uganda has changed and use of crater water at an altitude higher than 1,400 m above sea level poses a risk of acquiring S. mansoni infection in western Uganda. However, further research is required to establish whether the observed altitudinal threshold change is as a re
Sensitivity and specificity of serum cross-linked N-telopeptides of type 1 collagen (NTx) in patients with solid tumors
Fernando Jablonka,Fernanda Schindler,Paula Philbert Lajolo,Hélio Pinczowski
Einstein (S?o Paulo) , 2009,
Abstract: Objective: Cross-linked N-telopeptides of type I collagen (NTx) increase in situations in which bone resorption is increased, such as osteoporosis and bone metastasis. It was evaluated the usefulness of NTx for the diagnosis of bone metastases in patients with solid tumors. Methods: It was conducted a prospective study, at a tertiary public hospital. A quantitative enzyme-linked immunosorbent assay (ELISA) assay of serum NTx levels in 19 subjects without a history of cancer and 62 patients with various solid tumors referred for a bone scan was evaluated. Three specialists read all bone scans. Rresults: It was not found any significant correlations between serum NTx and age, sex, history of bone pain, tumor type and bone alkaline phosphatase levels. We found a significant correlation between serum NTx and alkaline phosphatase levels (r2 = 0.08, p = 0.022). Serum NTx sensitivity, specificity, positive and negative predictive values and area under the receiver operating characteristic (ROC) curve for the presence of bone metastases were 0.34, 0.92, 0.95, 0.22 and 0.59, respectively. Cconclusions: It was concluded that serum levels of NTx are highly sensitive for the diagnosis of bone metastases in patients with solid tumors.
Generalizations of generating functions for basic hypergeometric orthogonal polynomials
Howard S. Cohl,Roberto S. Costas-Santos,Philbert R. Hwang
Mathematics , 2014,
Abstract: We derive generalized generating functions for basic hypergeometric orthogonal polynomials by applying connection relations with one free parameter to them. In particular, we generalize generating functions for Askey-Wilson, Rogers/continuous $q$-ultrapherical, little $q$-Laguerre/Wall, and $q$-Laguerre polynomials. Depending on what type of orthogonality these polynomials satisfy, we derive corresponding definite integrals, infinite series, bilateral infinite series, and $q$-integrals.
Estresse na vida do acadêmico em enfermagem. (Des)conhecimento e preven o Estrés en la vida del académico en enfermería. (Des)conocimiento y prevención Stress in the nursing academic life. (Un) awareness and prevention
Sabrina Corral-Mulato,Vanessa Denardi Antoniassi Baldissera,Janaina Luiza dos Santos,Larissa Angélica da Silva Philbert
Investigación y Educación en Enfermería , 2011,
Abstract: Objetivo. Descrever a percep o do pessoal e profissional sobre o estresse, sua preven o e a abordagem da temática na forma o junto aos estudantes de enfermagem brasileiros. Metodologia. Foi desenvolvida uma investiga o qualitativa, descritivo-exploratoria, o ano de 2009, mediante aplica o de um questionário aberto. As respostas foram interpretadas através da análise temática, categorizando as variáveis qualitativas identificadas. Resultados. Participaram oito estudantes de sexo feminino que cursavam o último ano do pré-gradua o de enfermagem, com idades entre 21 e 27 anos. O estresse pessoal está relacionado às situa es de desequilíbrio e dificuldades na vida profissional, excesso de trabalho e falta de voca o, o qual tem como consequência manifesta es físicas e mentais. O tema do manejo do estresse foi abordado na forma o e se sentem preparadas para trabalhar essa temática em sua futura prática profissional, no entanto foi evidente a utiliza o do sentido comum para responder as perguntas de investiga o. As participantes prop em como estratégias de alívio do estresse o descanso, as atitudes otimistas e o autocontrole. Conclus o. As participantes do estudo relacionaram o estresse pessoal com as situa es de desequilíbrio e dificuldades na vida profissional, excesso de trabalho e falta de voca o. Objetivo. Describir la percepción personal y profesional sobre el estrés, su prevención y el abordaje de la temática en la formación junto a los estudiantes de enfermería brasile os. Metodología. Fue desarrollada una investigación cualitativa, descriptivo-exploratoria, el a o de 2009, mediante aplicación de un cuestionario abierto. Las respuestas fueron interpretadas a través del análisis temático, categorizando las variables cualitativas identificadas. Resultados. Participaron ocho estudiantes de sexo femenino que cursaban el último a o del pregrado de Enfermería, con edades entre 21 y 27 a os. El estrés personal está relacionado con las situaciones de desequilibrio y dificultades en la vida profesional, exceso de trabajo y falta de vocación, lo cual tiene como consecuencia manifestaciones físicas y mentales. El tema del manejo del estrés fue abordado en la formación y se sienten preparadas para trabajar esa temática en su futura práctica profesional, sin embargo fue evidente la utilización del sentido común para responder las preguntas de investigación. Las participantes proponen como estrategias de alivio del estrés el descanso, las actitudes optimistas y el auto-control. Conclusión. Las participantes del estudio relacionaron el estrés personal con
A Guide to Delineate the Logic of Neurovascular Signaling in the Brain
David Kleinfeld,Pablo Blinder,Patrick J. Drew,Jonathan D. Driscoll,Arnaud Muller,Philbert S. Tsai,Andy Y. Shih
Frontiers in Neuroenergetics , 2011, DOI: 10.3389/fnene.2011.00001
Abstract: The neurovascular system may be viewed as a distributed nervous system within the brain. It transforms local neuronal activity into a change in the tone of smooth muscle that lines the walls of arterioles and microvessels. We review the current state of neurovascular coupling, with an emphasis on signaling molecules that convey information from neurons to neighboring vessels. At the level of neocortex, this coupling is mediated by: (i) a likely direct interaction with inhibitory neurons, (ii) indirect interaction, via astrocytes, with excitatory neurons, and (iii) fiber tracts from subcortical layers. Substantial evidence shows that control involves competition between signals that promote vasoconstriction versus vasodilation. Consistent with this picture is evidence that, under certain circumstances, increased neuronal activity can lead to vasoconstriction rather than vasodilation. This confounds na?ve interpretations of functional brain images. We discuss experimental approaches to detect signaling molecules in vivo with the goal of formulating an empirical basis for the observed logic of neurovascular control.
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