285 research outputs found

    Aminoglycosides Rapidly Inhibit NAD(P)H Metabolism Increasing Reactive Oxygen Species and Cochlear Cell Demise

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    Despite causing permanent hearing loss by damaging inner ear sensory cells, aminoglycosides (AGs) remain one of the most widely used classes of antibiotics in the world. Although the mechanisms of cochlear sensory cell damage are not fully known, reactive oxygen species (ROS) are clearly implicated. Mitochondrial-specific ROS formation was evaluated in acutely cultured murine cochlear explants exposed to gentamicin (GM), a representative ototoxic AG antibiotic. Superoxide (O2·-) and hydrogen peroxide (H2O2) were measured using MitoSOX Red and Dihydrorhodamine 123, respectively, in sensory and supporting cells. A 1-h GM exposure significantly increased O2·- formation in IHCs and increased H2O2 formation in all cell types. At the same time point, GM significantly increased manganese superoxide dismutase (MnSOD) levels while significantly decreasing copper/zinc superoxide dismutase (CuZnSOD) in cochlear sensory cells. This suggests (1) a rapid conversion of highly reactive O2·- to H2O2 during the acute stage of ototoxic antibiotic exposure and (2) that the endogenous antioxidant system is significantly altered by AGs. Fluorescence intensity-based measurements of reduced nicotinamide adenine dinucleotide (phosphate) [NAD(P)H] and mitochondrial membrane potential were measured to determine if increases in GM-induced ROS production were correlated with changes in mitochondrial metabolism. This project provides a basis for understanding the mechanisms of mitochondrial ROS production in cochlear cells exposed to ototoxic antibiotics. Understanding the nature of ototoxic antibiotic-induced changes in mitochondrial metabolism is critical for developing hearing loss treatment and prevention strategies

    Design, fabrication and testing of shea nut shelling machine

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    Sheanut (Butyrospernum paradoxum) is an oil rich tropical tree crop, which is indigenous to the West African savannah zone. In Nigeria, most of the sheanuts shelling are done manually by rural women and children, which is labour demanding and tedious. This research work was carried out to determine some physical and mechanical properties of sheanut in order to minimize economic losses associated with its processing. The mean values recorded for the physical properties at 25% moisture content (wb) are; major diameter (29.20 mm), intermediate diameter (21.90 mm), minor diameter (15.00 mm), geometric mean diameter (21.90 mm), arithmetic mean diameter (21.20 mm), angle of repose (30.280). The mean values for the mechanical properties are; linear limit force (0.80 kN), linear limit deformation (4.60 mm), bioyield point force (1.40 kN), bioyield point deformation (6.50 mm), rupture point force (2.10 kN) and rupture point deformation (9.60 mm). Based on the physical and mechanical properties, a sheanut shelling machine was developed that is capable of addressing the aforementioned problems. Putting into consideration better shelling and efficient separation of shea nuts so as to encourage more utilization and processing of shea nuts and its products. The machine was designed to be powered by 5 hp electric motor. It was tested to shell, separate and clean sheanuts. The result of the performance evaluation showed that the machine had shelling efficiency of 96%; cleaning efficiency of the machine was 69.56% while the recovery efficiency was 82.7%. The successful development of this machine will reduce drudgery and time taken associated with the traditional method of sheanut shelling and therefore will increase productivity and utilization

    Effects of Salts Concentration on Emergence and Growth of Tomato (Lycopersicon Esculentum) in Tropical Areas

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    Irrigation water quality could have a significant impact on the growth and yield and hence the productivity of crops. All irrigation water contains some dissolves salts, but the concentration and composition of the salts vary with the source of the irrigation water. Water saving in irrigation was identified as a major subject in northern Nigeria. Therefore, the use of treated municipal wastewater and saline water as a complementary source for water irrigation has been encouraged to increase the efficient use of water irrigation in crop production. Thus, the present study was carried out to examine the effect of two salts (NaCl and KCl) in irrigation water at varying concentrations on the emergence and growth of tomato in a semi-arid environment. Potassium chloride was found to be more detrimental on the sustainable production of tomato, NaCl concentration up to 1.5 g/l however was be safely used to boost tomato production. The results show that the treated wastewater, brackish and saline waters and other unconventional sources of water can be safely used in improving agricultural programs under arid and semiarid regions

    Analysis of dielectrophoresis AC electrokinetic in equilibrium using MATLAB

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    This paper presents an ideal case for dielectrophoretic (DEP) occurrence to separate a mixture of two sizes of particles in microchannel analysed with DEP 3D equation using Matlab. The analysis was done on the particles mobility changes when the medium conductivity varied. The analysis was also done when the particles suspended in different mediums conductivity. The effect of dielectrophoresis on the velocity of the particle when the frequency increased has been successfully discovered

    Pemetaan Kerentanan Tsunami Kabupaten Lumajang Menggunakan Sistem Informasi Geografis

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    Kabupaten Lumajang merupakan wilayah yang rentan terhadap tsunami karena berbatasan langsung dengan Pantai Selatan yang menjadi pusat gempa bumi serta keadaan pesisir pantai selatan Lumajang yang memiliki tingkat kepadatan penduduk dan pemukiman, aktivitas pemerintahan dan perekonomian yang tinggi. Pemetaan tingkat kerentanan tsunami perlu dilakukan sebagai informasi mitigasi dan rencana tata ruang wilayah. Lokasi penelitian adalah 5 (lima) kecamatan di pesisir Pantai Selatan Lumajang yaitu Yosowilangun, Kunir, Tempeh, Pasirian, dan Tempursari. Tujuan penelitian ini adalah membuat peta kerentanan tsunami Kabupaten Lumajang menggunakan Sistem Informasi Geografis (SIG). Pendekatan variabel kerentanan meliputi elevasi daratan, kemiringan, morfometri pantai, penggunaan lahan, jarak dari pantai dan jarak dari sungai. Metodologi penelitian antara lain pengumpulan data primer dan sekunder, pengolahan data parameter yang mewakili tiap variabel kerentanan serta pemberian bobot dan skor. Hasil kajian ini menghasilkan peta-peta variabel kerentanan wilayah penelitian yang selanjutnya dapat digunakan untuk kebijakan pemerintah daerah dan tindakan mitigasi seperti pemetaan tingkat risiko tsunami

    A complex network approach to structural inequality of educational deprivation in a Latin American country

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    To guarantee the human right to education established by the fourth UNESCO’s Sustainable Development Goal, a deep understanding of a big set of non-linear relationships at different scales is need it, as well as to know how they impact on learning outcomes. In doing so, current methods do not provide enough evidence about interactions and, for this reason, some researchers have proposed to model education as a complex system for considering all interactions at individual level, as well as using computer simulation and network analysis to provide a comprehensive look at the educational processes, as well as to predict the outcomes of different public policies. The highlight of this paper is modeling the structure of the inequality of a national educational system as a complex network from learning outcomes and socio-economic, ethnicity, rurality and type of school funding, for providing a better understanding and measuring of the educational gaps. This new approach might help to integrate insights improving the theoretical framework, as well as to provide valuable information about non-trivial relationships between educational and non-educational variables in order to help policymakers to implement effective solutions for the educational challenge of ensuring inclusive and equitable education.info:eu-repo/semantics/acceptedVersio
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