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Search Results: 1 - 10 of 167563 matches for " E Okai "
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Genetic diversity within Ghanaian cowpea germplasm based on SDS-page of seed proteins
EYR Oppong-Konadu, HK Akromah, Adu Dapaah, E Okai
African Crop Science Journal , 2005,
Abstract:
4-dimensional dilaton black holes with cosmological constant
Tadashi Okai
Physics , 1994,
Abstract: Static and spherically symmetric black hole solutions with non-zero cosmological constant are investigated. A formal power series solution is found. It is proved that the number of regular horizons is less than or equal to 2 for positive cosmological constant and is less than or equal to 1 for negative cosmological constant. This shows a striking contrast to the fact that the Reissner-Nordstr{\o}m-de Sitter black hole with positive cosmological horizon has 3 regular horizons.
Mass Formulae of 4-Dimensional Dilaton Black Holes
Tadashi Okai
Physics , 1993, DOI: 10.1088/0264-9381/11/2/012
Abstract: Integral and differential mass formulae of 4-dimensional stationary and axisymmetric Einstein-Maxwell-dilaton systems are derived. The total mass (energy) of these systems are expressed in terms of other physical quantities such as electric charge of the black hole suitably modified due to the existence of the dilaton field. It is shown that when we vary slightly the fields (metric of the spacetime $g_{\mu\nu}$, $U(1)-$gauge potential $A_{\mu}$, and dilaton $\phi$) in such a way as they obey classical equations of motion, the variation of the dilaton does not contribute explicitly to the variation of the total mass, but contributes only through the variation of the electric charge of the black hole.
Global structure and thermodynamic property of the 4-dimensional twisted Kerr solution
Tadashi OKAI
Physics , 1994, DOI: 10.1143/PTP.92.47
Abstract: Rotating stringy black hole solutions with non-vanishing dilaton $\phi$, antisymmetric tensor $B_{\mu\nu}$, and $U(1)$ gauge field $A_{\mu}$ are investigated. Both Boyer-Lindquist-like and Kerr-Schild-like coordinate are constructed. The latter is utilised to construct the analytically extended spacetime. The global structure of the resulting extended spacetime is almost identical to that of the Kerr. In carrying out the analytic extension, the radial coordinate should be suitably chosen so that we can avoid singularity caused by the twisting. The thermodynamic property of the stringy black hole is examined through the injection of test bodies into the black hole. It is shown that one cannot change a black hole configuration into a naked singularity by way of throwing test bodies into the black hole. The global $O(2,3)$ symmetry and the preservation of the asymptotic flatness are discussed. When we impose stationarity, axisymmetry, and asymptotic flatness, there is no other twisting than the one pointed out by A.Sen\cite{sen}. All the other elements of $O(2,3)$ either break the asymptotic flatness, or cause only coordinate transformations and gives no physical change.
Extent of Awareness of Birth Control Methods and Their Use by Women in a Peri-Urban Area of Accra, Ghana  [PDF]
Kwabena Asomanin Anaman, Joana Okailey Aku Okai
Modern Economy (ME) , 2016, DOI: 10.4236/me.2016.71005
Abstract: The rapid population growth and economic expansion in Ghana over the last decade have made the management of its population increasingly important necessitating detailed confidential studies on use of birth control methods. This paper reports a highly confidential survey-based study undertaken to assess the extent of awareness of and factors influencing the use of birth control methods among 120 women aged between 15 and 49 years, in their reproductive lifespan, at Abokobi, a suburb of Accra, Ghana. The analysis showed that age was the main factor responsible for the general level of awareness of birth control methods. The use of birth control methods was positively related to the level of awareness of birth control methods, being in a current sexual relationship, and the number of children that the woman had. Students were less likely to use birth control methods than non-students suggesting the need for more recognition of abstinence as an alternative birth control method.
High Ethanol Production by Marine-Derived Yeasts-Saccharomyces cerevisiae under Stress Pressures  [PDF]
Naoto Urano, Ayaka Shirao, Masahiko Okai, Masami Ishida
Advances in Microbiology (AiM) , 2017, DOI: 10.4236/aim.2017.75029
Abstract: For practical applications of bioethanol, the uses of both highly concentrated biomass materials and their effective fermentation by yeasts are indispensable in order to produce ethanol at low costs. However, as the saccharified products of those biomass generally contain abundant sugars, the yeasts are affected by the compounds and are inclined to decrease their physiological activities. In the process of fermentation, ethanol is gradually produced by the yeasts in the culture; the concentrated metabolic product also damages itself, and inhibition of the fermentation frequently occurs. The application of yeasts with high fermentative activities under stress pressures such as sugars and ethanol is thus desired for bioethanol production. In this study, various types of high-fermentative yeasts under stress pressures were isolated mainly from coastal waters in Japan and characterized. All yeast strains with high fermentative activities under 20% v/v ethanol were found to be Saccharomyces cerevisiae. The HK21 strain isolated from Tokyo Bay and identified as S. cerevisiae had the highest fermentation activity under 30% w/v sorbitol and under 20% v/v ethanol, and it produced approx. 70 g/l (9% v/v) ethanol from the 15% w/v glucose solution at 25 oC within 5 days.
Changes in FDB and soleus muscle activity after a train of stimuli during upright stance
Okai, Liria A.;Kohn, André F.;
Brazilian Journal of Physical Therapy , 2012, DOI: 10.1590/S1413-35552012005000024
Abstract: background: evidence of self-sustained muscle activation following a brief electrical stimulation has been reported in the literature for certain muscles. objectives: this report shows that the foot muscle (flexor digitorum brevis - fdb) shows a self-sustained increase in muscle activity during upright stance in some subjects following a train of stimuli to the tibial nerve. methods: healthy subjects were requested to stand upright and surface emg electrodes were placed on the fdb, soleus and tibialis anterior muscles. after background muscle activity (bga) acquisition, a 50 hz train of stimuli was applied to the tibial nerve at the popliteal fossa. the root mean square values (rms) of the bga and the post-stimulus muscle activation were computed. results: there was a 13.8% average increase in the fdb muscle emg amplitude with respect to bga after the stimulation was turned off. the corresponding post-stimulus soleus emg activity decreased by an average of 9.2%. we hypothesize that the sustained contraction observed in the fdb following stimulus may be evidence of persistent inward currents (pic) generated in fdb spinal motoneurons. the post-stimulus decrease in soleus activity may have occurred due to the action of inhibitory interneurons caused by the pics, which were triggered by the stimulus train. conclusions: these sustained post-stimulation changes in postural muscle activity, found in different levels in different subjects, may be part of a set of possible responses that contribute to overall postural control.
Nutrient composition, insect pests and microbial population in rice bran samples from some mills in Kumasi and its environs
DB Okai, EKD Nyannor, I Tandoh
Journal of Science and Technology (Ghana) , 2003,
Abstract:
Purification, Characterization and Gene Cloning of High-molecular-weight Xylanase-4 of Aeromonas caviae W-61
Narayan Roy,Naoko Okai,Yoshiyuki Kamio
Pakistan Journal of Biological Sciences , 2001,
Abstract: Aeromonas caviae W-61 produces multiple extracellular xylanases, the xylanases 1, 2, 3, 4, and 5. In this study, we purified and characterized the xylanase-4 gene of A. caviae W-61, and cloned it. The purified xylanase-4 consisted of a single polypeptide with molecular masses of 120 kDa. The xylanases 4 was endo- -1,4-xylanase with optimum temperature 40°C, optimum pH 6.0 and temperature stability 40-50 C. Various xylo-oligosaccharides such as xylobiose, xylotriose, xylotetraose, xylopentaose and xylohexaose were formed, and a small amount of xylose was detected as the hydrolysis products. The N-terminal amino acid sequence and several identical internal amino acid sequences of xylanases-4 were determined. From the sequence, 1.8 kbp xyn 4 was amplified by PCR and was cloned from the genomic DNA of A. caviae W-61. The flanking region of xylanase-4 were sequenced and it contained a sequence corresponding a typical signal peptide consisting of 27 amino acid residues at the 5` end. Putative promotor ( 35 and 10) sequences and a typical ribosome-binding sequence were present upstream the xyn 4
Changes in FDB and soleus muscle activity after a train of stimuli during upright stance Altera es pós-trem de estímulo, na atividade dos músculos FDB e sóleus durante a postura ortostática
Liria A. Okai,André F. Kohn
Brazilian Journal of Physical Therapy , 2012,
Abstract: BACKGROUND: Evidence of self-sustained muscle activation following a brief electrical stimulation has been reported in the literature for certain muscles. OBJECTIVES: This report shows that the foot muscle (Flexor Digitorum Brevis - FDB) shows a self-sustained increase in muscle activity during upright stance in some subjects following a train of stimuli to the tibial nerve. METHODS: Healthy subjects were requested to stand upright and surface EMG electrodes were placed on the FDB, Soleus and Tibialis Anterior muscles. After background muscle activity (BGA) acquisition, a 50 Hz train of stimuli was applied to the tibial nerve at the popliteal fossa. The root mean square values (RMS) of the BGA and the post-stimulus muscle activation were computed. RESULTS: There was a 13.8% average increase in the FDB muscle EMG amplitude with respect to BGA after the stimulation was turned off. The corresponding post-stimulus Soleus EMG activity decreased by an average of 9.2%. We hypothesize that the sustained contraction observed in the FDB following stimulus may be evidence of persistent inward currents (PIC) generated in FDB spinal motoneurons. The post-stimulus decrease in soleus activity may have occurred due to the action of inhibitory interneurons caused by the PICs, which were triggered by the stimulus train. CONCLUSIONS: These sustained post-stimulation changes in postural muscle activity, found in different levels in different subjects, may be part of a set of possible responses that contribute to overall postural control. CONTEXTUALIZA O: Existem evidências de ativa o autossustentada em certos músculos pós-estimula o elétrica. OBJETIVOS: Mostrar que, em alguns sujeitos, o músculo do pé (Flexor Digitorum Brevis - FDB) também pode apresentar aumento de atividade autossustentada na posi o ortostática pós-trem de estímulo no nervo tibial. MéTODOS: Sujeitos foram solicitados a permanecer na posi o ortostática e sinais eletromiográficos foram coletados dos músculos FDB, sóleus e tibial anterior do membro inferior direito. Após a aquisi o dos sinais eletromiográficos base (sem estimula o - BGA), um trem de estímulos de 50 Hz foi aplicado no nervo tibial (fossa poplítea). Foram analisados os valores RMS dos dados BGA e dos sinais coletados pós-estímulo. RESULTADOS: Ao fim do estímulo, houve um aumento de 13,8% da atividade muscular do FDB em compara o com BGA. O mesmo fen meno n o aconteceu com o músculo sóleus, que apresentou uma diminui o de 9,2% da sua atividade pós-estímulo. Uma das hipóteses para a gera o pós-estímulo da contra o sustentada do FDB s
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