Tertiary conformational transition in sheep hemoglobins induced by reaction with 5,5´-dithiobis(2-nitrobenzoate) and by binding of inositol hexakisphosphate

We have determined the second-order reverse rate constant, kR, for the reaction of 5,5´-dithiobis(2- nitrobenzoate) – DTNB – with sheep hemoglobins as a function of pH from values of the second-order forward rate constant, kF, and the equilibrium constant, Kequ, at 25 °C: kR¼ kF Kequ. We demonstrate that (i) inositol hexakisphosphate (inositol-P6) decreases kF and kR by increasing Krt, the r⇌t tertiary conformation transition constant; (ii) the conformation favored for both the forward and reverse reactions is the r conformation. For stripped hemoglobin we obtain from the kF data a t isomer population of 34.6% (±14) prior to reaction with DTNB; from the kR data we calculate a t isomer population of 44.8% (±4) following reaction with DTNB. In the presence of inositol-P6 the latter value is increased to 79.5% (±2). These results demonstrate that an allosteric transition occurs on reaction with DTNB and on inositol-P6 binding

Transition of haemoglobin between two tertiary conformations: Inositol hexakisphosphate increases the transition constant and the affinity of sheep haemoglobin for 5,5′-dithiobis(2-nitrobenzoate)

The equilibrium constant (Kequ) for the reaction of 5,5′-dithiobis(2-nitrobenzoate) — DTNB — with the CysF9 [93]β sulphydryl group of the haemoglobins of the sheep decreases by about two orders of magnitude between pH≈5.6 and 9.2: from a mean of 7.2±1 to a mean of 0.044±0.01. Calculations from the pH dependence of Kequ show that in the r⇌t tertiary conformational transition of haemoglobin the t isomer population is 50.7 and 61.8% for the major and minor haemoglobins, respectively. In the presence of inositol hexakisphosphate (inositol-P6), Kequ increases for both haemoglobins by about an order of magnitude through most of the pH range. The t isomer population also increases to 82.1 and 79.6% for the major and minor haemoglobins, respectively. These results indicate that inositol-P6 increases the affinity of the sulphydryl for DTNB by increasing the population of the t isomer. It is highly probable that a minimum fourstate model that includes the r⇌t transition is required for a full understanding of haemoglobin function

Effect of cold temperature storage on the quality attributes of pawpaw and guava leathers

The effect of cold temperature storage on the quality attributes of pawpaw and guava leathers was evaluated. Pawpaw leather was significantly higher than guava leather in calorific content, water activity, pH and total mould count throughout the duration of storage. However Guava leather was higher in texture. Sensory scores in relation to period of storage showed that Guava leather gave better result in overall acceptability at zero, one and two months of storage at 8 ± 10C. Guava leather also gave better sensory qualities in fruitiness, smell, chewiness, toughness, colour, and overall acceptability when varietal influence is considered. Guava leather is better accepted. (African Journal of Biotechnology: 2002 1(2): 61-63

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Entrepreneurial Orientation Components and Sales Volume of Selected Quoted Consumer Goods Manufacturing Companies in Nigeria

Organisational performance is of high importance and occupies a central position among other goals and remains a compensation for sustainable and competitive sales volume. Consumer goods manufacturing industry in Nigeria are experiencing decline in sales volume due to poor entrepreneurial orientation. This study examined the interaction between entrepreneurial orientation components and sales volume of selected quoted consumer goods manufacturing companies in Nigeria. The study adopted cross sectional survey design. The population of the study was 1,551. Total enumeration was used to sample the entire population. A structured questionnaire was used for data collection. The Cronbach’s alpha ranges between 0.721 and 0.892. The response rate was 90.5%. Data were analysed using descriptive and inferential statistics. Findings revealed that innovativeness (β = 0.334, t = 4.970, p = 0.000), competitive aggressiveness (β = 0.221, t = 3.715, p = 0.000) and risk taking (β = 0.136, t = 2.044, p = 0.042) have positive and significant effects on sales volume of the selected quoted consumer goods companies in Nigeria. However, proactiveness (β = 0.129, t = 1.733, p = 0.000) and planning flexibility (β = 0.075, t = 1.378, p = 0.169) have a positive but insignificant effect on sales volume of selected quoted consumer goods companies in Nigeria. The study concluded that entrepreneurial orientation (innovativeness, competitive aggressiveness, proactiveness, risk-taking and planning flexibility) had significant effect on sales volume of selected quoted consumer goods companies in Nigeria and recommended that managers should be more aggressive in exploiting opportunities to increase sales volume. Keywords: Entrepreneurial orientation, Sales volume, Consumer goods companies, Nigeria. DOI: 10.7176/JRDM/80-03 Publication date: November 30th 202

Dynamic Performance Analysis of Cogeneration Potential in Photovoltaic Power System.

The solar cell junction is susceptible to performance degradation, due to internal temperature rise which is further perturbed by ambient temperature rise. The conversion efficiency of the solar module remarkably drops because of temperature rise. The diurnal module temperature hovers above 60 degrees C. It is possible to keep the conversion efficiency high by water-cooled or air blast equipment. This project is a preliminary study of the impact of temperature variation across seasons on the dynamic performance of photovoltaic power system. The photovoltaic (PV) module was mounted on a test rig at latitude 7 degree on top of physics building Obafemi Awolowo University campus. The output voltage of the PV module was applied to a resistive load and system efficiency performance measured over a period of time covering the dry and rainy seasons. Measurements of ambient temperature, PV junction operating temperature, wind speed, solar irradiance, and power delivered were carried out. A numerical algorithm was developed to analyse the data. The transport medium can store heat energy from the solar module, so that a large amount of hot water can be produced. The results show that this thermal transfer benefit, positions the PV system in good stead, for Microgrid: Cogeneration Energy Efficiency functionality. Keywords: Conversion efficiency, Photovoltaic power system, PV module, Water-cooled equipment, Cogeneration

INFLUENCE OF BRADYRHIZOBIUM AND TWO GLOMUS SPECIES ON THE GROWTH AND YIELD OF SOYBEAN

A screenhouse experiment was conducted to investigate the effect of Bradyrhizobium japonicum on the response of soybean to inoculation with two species of mycorrhiza (Glomus mosseae and Glomus deserticola). The study was carried out in a screenhouse with soybean as test crop. The two species of arbuscular mycorrhiza fungi (AMF) were inoculated to the potted soil with or without B. japonicum. Single super phosphate (SSP) and zero amendment served as conventional and absolute control respectively. The experimental design was randomized complete block with 4 replicates. AMF/Bradyrhizobium interaction increased mycorrhizal fungi root colonization significantly (p = 0.05) by at least 35.9% at early growth stage (3 weeks after planting (WAP)) and 59.5% at later growth stage (9 WAP). G mosseae/Bradyrhizobium interaction significantly increased N and P uptakes by 68.9 and 80.0%, respectively, as well as plant height, number of leaves, number of branches, canopy spread and leaf area between 2 and 5 WAP. Soybean biomass increased significantly due to interaction of G mosseae and Bradyrhizobium by 42.2-53.4% between 3 and 9 WAP and nodule weight increased by 61.9-93.3% between 6 and 9 WAP. Grain yield per plant was similar in all AMF treatments and SSP but less in sole Bradyrhizobium inoculation by 37.5% and in control by 33.3%. AMF/Bradyrhizobium interactions produced higher N by up to 81% in the residual soil and the P content was similar to SSP but higher than in control by up to 32.3%. Interaction of G mosseae and Bradyrhizobium increased spores of mycorrhizal fungi in the soil by 41% at 3 WAP and 74.7% at 9 WAP. It was concluded that although Bradyrhizobium had a positive and synergistic influence on the activities of the two species of mycorrhizal fungi inoculated on soybean, the influence was, however, more pronounced on G mosseae than G deserticola

Entrepreneurial Orientation, Economic Factors and Performance of Selected Quoted Consumer Goods Manufacturing Companies in Nigeria: A Combined Effect

Performance does take central position in terms of business considering its role in assisting organisations to accomplishing goals and achieving successes. Consumer goods manufacturing industry in Nigeria are experiencing decline in performance these days due to poor entrepreneurial orientation and poor management of economic policies. This study examined entrepreneurial orientation, economic factors and performance of selected quoted consumer goods companies in Nigeria. Cross sectional survey design was employed and the population of the study was 1,551 of twelve (12) quoted consumer goods manufacturing companies in Nigeria. A structured questionnaire was used for data collection. The Cronbach’s alpha ranges between 0.721 and 0.892. The response rate was 90.5%. Data were analyzed using descriptive and inferential statistics. The results revealed that entrepreneurial orientation (β = 0.420, t = 7.288, p = 0.000) and economic factors (β = 0.671, t = 11.098, p = 0.000) have positive and significant effects on performance of the selected quoted consumer goods companies in Nigeria. This implies that entrepreneurial orientation and economic factor are significant predictors of performance of selected quoted consumer goods companies in the study area. The study concluded that entrepreneurial orientation and economic factors had significant effects on performance of selected consumer goods companies in Nigeria and recommended that managers of selected consumer goods companies should be strategic and proactive enough to improve on performance of consumer goods manufacturing companies in Nigeria. Keywords: Entrepreneurial orientation, Economic factors, Consumer goods companies, Nigeria. DOI: 10.7176/EJBM/13-22-03 Publication date: November 30th 202

Estimating True Movement In Time Series As Linear Combination Of Two Indicators

This paper describes an iterative procedure for estimating true change in a time series as a linear combination of two imperfect indicators with weight chosen to minimize errors particularly when the time series (dependent variables) is not or cannot be observed, this research work was compiled to estimate the coefficients of the ?’s responsiveness of indicators to change in true series, in order to determine the equation that connect variables. It also describes how an appropriate weight could be chosen for the two indicators as to error. We found that; the best estimation for changing the number of caesarean section is; T1 = 0.1720x + 0.967y1- 0.0287 The length of stay in hospital series received a substantial weight compared to the weight of parity series. The final estimate of ax to be positive and reduction of error expected from using the proposed procedure was estimated at about 6% and 27%  per month compared to both parity and length of stay in hospital indicators respectively. Key Words: Imperfect Indicators, True Series, Weighted Time serie

Design and construction of tilting furnace for producing aluminium matrix composites

Aluminium matrix composites (AMCs) are a range of advanced engineering materials that can be used for a wide range of applications within the aerospace, automotive, biotechnology, electronic and sporting goods industries. AMCs consist of a non-metallic rein~orcemeht (SiC) incorporated into Aluminium matrix which provides advantageous properties over base metal (AI) alloys. These include improved thermal conductivity, abrasion resistance, creop resistance, dimensional stability, exceptionally good stiffness-toweight and strength-to-weight ratios and better high temperature performance. Oil fired 20 kG tilting furnace with integral mixing mechanism was designed and constructed for the production of AMC. This cost effective furnace can be used in cottage industries without electric power