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História da fitovirologia no Brasil
Costa, A.S.;
Anais da Escola Superior de Agricultura Luiz de Queiroz , 1986, DOI: 10.1590/S0071-12761986000100005
Abstract: o presente trabalho é uma revis?o histórica sucinta da atua??o de fitopatologistas, fitovirologistas e outros técnicos no brasil na área das viroses de plantas. é considerado que a estrutura atual da pesquisa fitovirológica existente a nível federal ou estadual no país é suficiente para enfrentar problemas representados pelas viroses de nossas culturas. mas é apontado que há falta de uns poucos centros de pesquisa básica com vírus de plantas independentemente de considera??es econ?micas de problemas existentes. é mencionado que há dificuldade. em obter recursos para qualquer institui??o ou grupo que trabalhe em pesquisas mais básicas e que essas s?o melhor adaptadas a uma universidade ou instituto altamente especializado.
The inclusion of surface characteristics in equations for turbulence closure
Telles, A.S.;
Brazilian Journal of Chemical Engineering , 2000, DOI: 10.1590/S0104-66322000000400006
Abstract: the possibility of the inclusion of the charactheristics of surfaces in the formulation of closure equations for the turbulent fluxes is considered. the general formulation is presented in the form of an expression which, with respect to the fluid motion, it is a general constitutive equation as proposed by noll, and to which, it was added the explicit dependence upon the wall configuration. restrictions imposed by frame indifference, and by the symmetry group of the surface are examined.
Bradykinin enhances membrane electrical activity of pancreatic beta cells in the presence of low glucose concentrations
Moura, A.S.;
Brazilian Journal of Medical and Biological Research , 2000, DOI: 10.1590/S0100-879X2000000900016
Abstract: in most of cells bradykinin (bk) induces intracellular calcium mobilization. in pancreatic beta cells intracellular calcium is a major signal for insulin secretion. in these cells, glucose metabolism yields intracellular atp which blocks membrane potassium channels. the membrane depolarizes, voltage-dependent ca2+ channels are activated and the intracellular calcium load allows insulin secretion. repolarization occurs due to activation of the ca2+-dependent k+ channel. the insulin secretion depends on the integrity of this oscillatory process (bursts). therefore, we decided to determine whether bk (100 nm) induces bursts in the presence of a non-stimulatory glucose concentration (5.6 mm). during continuous membrane voltage recording, our results showed that bursts were obtained with 11 mm glucose, blocked with 5.6 mm glucose and recovered with 5.6 mm glucose plus 100 nm bk. thus, the stimulatory process obtained in the presence of bk and of a non-stimulatory concentration of glucose in the present study suggests that bk may facilitate the action of glucose on beta cell secretion.
Perceived Effects of Faming-Related Health Problems of Farmers’ Productivity in Yewa North Area of Ogun State, Nigeria
A.S. Onasanya
The Social Sciences , 2013,
Abstract: This study investigated the perceived effects of farming related health problems on farmers productivity in selected villages in Yewa North Local Government area of Ogun State, Nigeria. The study covered fourteen villages, from which a total of 152 farmers were randomly selected and interviewed using a structured interview schedule. The study revealed that the common farming related health problems among the farmers include: Body itching, general body pain, matchet cut and malaria (Iba). The farmers resorted into past experiences (self medication) and visiting health centers in order to solve their health problems. The study revealed that the farmers perceived that the effects of farming related health problems was high ( = 3.90) on their productivity in the study area. Specifically, they perceived that body itching suffered during farming activities results in low farm turn out and ultimately on low productivity and that adequate rest should be observed after farming activities, so that it will improve their promptness to work the following day, thereby leaving no space for lapses on their farm work, hence leading to improve productivity. Also, the study showed that most of the farmers agreed that cold fever can result to farmers death thereby paralyzing their productivity, while improper handling of some chemicals can result to skin rashes which in return reduces time available for farm activities and ultimately lowers farmers productivity. They also perceived that ineffectiveness, inefficiency and reduced productivity could be as a result of fire burns, inhalation of pollens, insect stings and deep cuts from sharp objects. The study concluded that there were no significant relationships between the effects of farming related health problems and selected personal characteristics of the farmers. Specifically, no relationship exists between perceived effects of farming related health problems and age (χ2 calculated = 0.811, p>0.05); marital status (χ2 calculated = 0.532, p>0.05), household size (χ2 calculated = 0.903, p>0.05) and educational level (χ2 calculated = 0.519, p>0.05) of the farmers. This is an implication that the effect farming related health problems are not influenced by he selected personal characteristics of farmers. The study therefore, recommended that farmers should be properly educated on personal health care and the type of farming systems that will not endangered their health by extension agents. Also, government should encourage the farmers by providing farming implements that can be hired by farmers to reduce drudgery on their farms at reasonable costs, hence enhancing their productivity without jeopardizing their health.
Debt Forgiveness and its Impact on the Growth of Nigerian Economy: An Empirical Study
A.S. Bakare
Pakistan Journal of Social Sciences , 2012, DOI: 10.3923/pjssci.2010.34.39
Abstract: Despite the debt forgiveness to the tune of $18 billion received by Nigeria from Paris club since year 2005 including the subsequent payment of $12 billion to upset the remaining debt, there is no evidence of accelerating pace of growth and development of the country. It is therefore, instructive to find out the direction and the extent of the effectiveness of the debt relief granted to Nigeria. This forms the objective of this study. The secondary data used for the investigation were processed using the ordinary least square packages. The result of the OLS model showed that the debt overhang problem of Nigeria has been alleviated by the debt relief package but the debt service relief did not positively influence the growth indicator. The results strongly support the need for tougher conditionality in future debt forgiveness initiative. Donor countries should monitor the allocation pattern of debt relief maintain the conditionalities and reward sound policies and improvements of governance quality in debtor countries.
Multinational Direct Investment and Economic Growth in Nigeria: An Empirical Study
A.S. Bakare
International Business Management , 2012, DOI: 10.3923/ibm.2010.171.176
Abstract: One of the major macroeconomic variables that stimulate growth is investment. Economic theories have shown that there is a causal relationship between economic growth and the increase in investment. This study, however examined the growth implications of multinational direct investment in Nigeria. The results of the data analysis and estimation were obtained using the parsimonious error correction mechanism. The result demonstrated that there is a positive relationship between multinational direct investment and growth in Nigeria. It shows that 1% rise in multinational direct investments will cause as much as 80% growth in the gross domestic output. This result indicated that multinational direct investment has the greatest influence on the growth of Nigerian economy compare to other variable in the model and strongly support the need for the government to encourage multinational corporation to establish more direct foreign investment in Nigeria. This is possible by simplifying the screening process and by creating more conducive political, social and economic environment for effective operation of multinational corporations.
The Role of the Dar es Salaam Stock Exchange in Safeguarding Securities Investors in Tanzania
A.S. Norman
International Business Management , 2012, DOI: 10.3923/ibm.2010.222.228
Abstract: This study examines the roles/functions of the Dar es Salaam Stock Exchange (DSE) in safeguarding the investors of securities in Tanzania. The business of securities, both bonds and shares has taken a new dimension since its establishment in Tanzania. It has attracted many people of different cadre. However, some investors have been doubtful on whether they should invest or not. The doubts seem to be cemented on risk associated with investing. This study therefore, expounds the role of DSE through narrating measures that have been put in place for safeguarding the investors of securities. The study utilizes mixed methodologies of data collection with documentary and the use artifacts taking the leading role. The study concludes that there are measures that have been put in place through rules and regulations with the view to protecting investors of stock exchange. However, it is the investors responsibility to attain necessary information regarding the firms that sell bonds and or shares and studying, among others, the financial information of the firms so as to realize the performance and prospective opportunities of the firms.
Evolutionary trend of the Jarawa younger granites ring complex, Jos plateau, central Nigeria
A.S Adubok
Science World Journal , 2008,
Abstract: The Jarawa Younger Granites Ring Complex which occupies the eastern flank of the popular Jos-Bukuru Ring Complex in Central Nigeria was geologically and geochemically investigated in order to identify the different lithologic units that make up the formation, as well as understand its geochemistry. These were used to unravel its mode of emplacement. Geological field studies revealed that the Jarawa Younger Granites evolved from two major phases of intrusions, the Hornblende Porphyry phase that was accompanied by the Hornblende Biotite Granites and the coarse grained Biotite Granite phase associated with the Biotite Microgranites. Results from geochemical studies supports the above findings, indicating high CaO and MgO content that decreases from the Hornblende Porphyry through the Hornblende Biotites to the coarsed grained Biotite Granites and the Microgranites respectively. Also, all the lithologic units exhibited high alkali content (Na2O + K2O) suggesting secondary magma source for the Jarawa Younger Granites Ring Complex.
Seasonal influence on microbial quality of water sources in some rural communities of Zaria, Nigeria.
A.S Hassan
Science World Journal , 2009,
Abstract: This work examined fifteen (15) different water sources in some rural communities of Zaria, Nigeria for microbial index of water quality in relation to seasonal influence from June, 2005 to May, 2006. The microbiological quality indices indicated widespread fecal contamination with the on-set of rainy season Escherichia coli MPN-index indicated highly significant difference between seasons, stations, season by stations and year by stations (P<0.01). The microbial quality of the water sources located near point sources of fecal contamination (pit latrine, sanitary drainage) raised some points of concern particularly during the rainy season when the water sources become extensively contaminated. Such contamination, coupled with the corresponding high temperature associated with tropical waters, and poor hygiene stand as potential indicators for pathogenic transmission.
An Almost Ideal Demand System (AIDS) for Forest and Agricultural Land Demand in Nigeria
A.S. Oyekale
Pakistan Journal of Social Sciences , 2012,
Abstract: Nigerian land use demand model was estimated using the AIDS model. Results showed that restricted method of estimation gives a better result than the unrestricted considering the significance of hectarage elasticities. The assumption of homogeneity was violated by the unrestricted method of estimation. Both the restricted and unrestricted methods of AIDS model estimation comply with the assumption of adding up, although, both violate the symmetry assumption. Increase in national income will lead to increase in the total hectare demanded in all the land use classes. Substitution or price effect is stronger as a factor influencing demand for all the land use classes. Permanent cropland and arable land show complementary relationship from the cross price elasticity. Arable land and permanent pasture show complementary relationship. Forest and woodland versus permanent crops are substitutes.
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