17 research outputs found
Genes Related to Fat Metabolism in Pigs and Intramuscular Fat Content of Pork: A Focus on Nutrigenetics and Nutrigenomics
No full textFat metabolism and intramuscular fat (IMF) are qualitative traits in pigs whose development are influenced by several genes and metabolic pathways. Nutrigenetics and nutrigenomics offer prospects in estimating nutrients required by a pig. Application of these emerging fields in nutritional science provides an opportunity for matching nutrients based on the genetic make-up of the pig for trait improvements. Today, integration of high throughput “omics” technologies into nutritional genomic research has revealed many quantitative trait loci (QTLs) and single nucleotide polymorphisms (SNPs) for the mutation(s) of key genes directly or indirectly involved in fat metabolism and IMF deposition in pigs. Nutrient–gene interaction and the underlying molecular mechanisms involved in fatty acid synthesis and marbling in pigs is difficult to unravel. While existing knowledge on QTLs and SNPs of genes related to fat metabolism and IMF development is yet to be harmonized, the scientific explanations behind the nature of the existing correlation between the nutrients, the genes and the environment remain unclear, being inconclusive or lacking precision. This paper aimed to: (1) discuss nutrigenetics, nutrigenomics and epigenetic mechanisms controlling fat metabolism and IMF accretion in pigs; (2) highlight the potentials of these concepts in pig nutritional programming and research
Methods of changing slaughter age at the same time bodyweight: effects on feed efficiency and green ham traits of heavy-pigs
No full textThe implications of changing age and weight at slaughter of heavy pigs on carcass and green ham quality traits
No full textItalian dry-cured ham production requires pigs to be slaughtered at 160 ± 16 kg at 9 months of age (control, C). The study explored three alternatives, based on different feeding conditions: (1) allowing pigs to express their growth potential by letting them reach 160 ± 16 kg slaughter weight (SW) at younger slaughter age (SA) (younger Age, YA); (2) allowing pigs to express their growth potential by maximizing their SW at 9 months SA (greater weight, GW); (3) increasing the SA required to reach 160 ± 16 kg SW (older age, OA). Pigs (336 C21 Goland, 95 kg initial body weight) were slaughtered on average at 257, 230, 257, and 273 d SA and 172.7, 172.3, 192.9, and 169.3 SW kg for the four treatments, respectively. C pigs had an average daily gain (ADG) of 715 g/d and feed efficiency (FE) of 0.265 (gain to feed). Compared to C, YA pigs had higher ADG (+32%), FE (+7.5%), and better ham adiposity; GW pigs had higher carcass weight (+12%), ADG (+25%), trimmed ham weight (+10.9%), and better ham adiposity. OA treatment affected ADG (−16.4%), FE (−16.6%), and trimmed ham weight (−3.6%). YA and GW could be promising alternatives to C as they improved FE and ham quality traits
Insecticidal activity of Wild Spikenard (Hyptis suaveolens L. Poit) on Adult Mortality and Female Oviposition of Groundnut Bruchid, Caryedon serratus Olivier on stored Groundnut Seeds and Tamarind pods
No full textAn investigation was conducted to estimate the insecticidal deterrence of wild Spikenard (Hyptis suaveolens L. Poit) on adult mortality and female oviposition of groundnut bruchid, Caryedon serratus Olivier on stored groundnut seeds and tamarind pods. Data were taken on mean percentage mortality and mean number of eggs laid (female oviposition). The highest mean percentage mortality for both stored produces were reported in actellic dust and 12.00g levels of H. suaveolens whole powders (93.50; 91.75 and 92.25; 91.25) while the least were obtained in the controls (4.75; 3.25). Moreover, 12.00g levels of H. suaveolens whole powder and actellic dust recorded the least mean number of eggs laid (female oviposition) (18.00; 17.00 and 19.25; 18.00) while the highest was reported in the controls (318.25; 305.50) respectively. There was no significant difference between the effects of rates of synthetic insecticides and 12.00g level of H. suaveolens whole powder in all the parameters measured.</jats:p
Maximum Power Point Tracking in Partial Shaded Photovoltaic System using Smell Agent Optimization Algorithm
No full textWith partial shading conditions, it is essential to acquire Maximum Power Point at which the Photovoltaic systems (PV) operate effectively despite the variation in the cell temperature and incident angle of sunlight rays on the panels. This study explores the use of a Smell Agent Optimization (SAO) algorithm for Maximum Power Point Tracking (MPPT) in partial shaded PV systems. The proposed MPPT system is composed of a PV model, a DC-DC converter model and a control part. The Smell Agent Algorithm (SAA) was adopted in the control part of the MPPT system to implement the optimization algorithm using four different shading patterns (SPs) and to calculate the optimal switching duty cycle of the DC-DC converter. The effectiveness of the proposed system was verified using simulations in the MATLAB/Simulink environment. The SAO respectively track maximum values for Power, Voltage and Current as 845.8476 W, 211.7308 V, 3.99492 A while the maximum values for Power, Voltage and Current for Perturb and Observe (P and O) are 845.0465 W, 211.6305 V, 3.993028 A respectively during SP1. The results showed that the SAO algorithm has excellent tracking results in terms of convergence speed, accuracy, power extracted stability, and dynamic response in reaching the optimum point
Maximum Power Point Tracking in Partial Shaded Photovoltaic System using Smell Agent Optimization Algorithm
No full textWith partial shading conditions, it is essential to acquire Maximum Power Point at which the Photovoltaic systems (PV) operate effectively despite the variation in the cell temperature and incident angle of sunlight rays on the panels. This study explores the use of a Smell Agent Optimization (SAO) algorithm for Maximum Power Point Tracking (MPPT) in partial shaded PV systems. The proposed MPPT system is composed of a PV model, a DC-DC converter model and a control part. The Smell Agent Algorithm (SAA) was adopted in the control part of the MPPT system to implement the optimization algorithm using four different shading patterns (SPs) and to calculate the optimal switching duty cycle of the DC-DC converter. The effectiveness of the proposed system was verified using simulations in the MATLAB/Simulink environment. The SAO respectively track maximum values for Power, Voltage and Current as 845.8476 W, 211.7308 V, 3.99492 A while the maximum values for Power, Voltage and Current for Perturb and Observe (P and O) are 845.0465 W, 211.6305 V, 3.993028 A respectively during SP1. The results showed that the SAO algorithm has excellent tracking results in terms of convergence speed, accuracy, power extracted stability, and dynamic response in reaching the optimum point
Lipid Peroxidation and Antioxidant Enzymes Evaluation in Lactating Female Albino Rats Following Supplementation with Fermented Soya Bean and Vitamin C
No full textThe estimation of groundwater recharge by soil water balance in semi-arid regions
No full textQuantification of groundwater recharge is a crucial prerequisite for sustainable
groundwater resource management, particularly in semi-arid areas where there are large
demands for groundwater supplies. This research presents an alternative approach for
recharge estimation based on the soil water balance technique. The purpose is to
develop a model which provides a suitable balance between physical credibility and
data which realistically can be gathered.
A spreadsheet model was written based on the conceptual representation of the principal
physical processes which actually affect recharge in a semi-arid area. Alternative
procedures were included in order to represent: (a) the estimation of runoff, (b) the
inclusion of the period with predominant bare soil evaporation and (c) the accounting
for evapotranspiration following rainfall on dry soil.
The model was tested using real data from a semi-arid region (Northeast Nigeria)
making use of selected periods of days and years in order to illustrate the principal
model characteristics. The results were presented in the form of diagrams and graphs
helping to visualise the interactions between the physical components and the effect of
the additional procedures on recharge estimation.
The credibility of the model was investigated using an alternative concept of "analysis
of plausibility". This concept makes use of as wide as possible a range of quantitative
and qualitative information from the hydrological system in order to verify the
robustness of the model when extensive datasets required by conventional validation
techniques are not available. The results suggested that the modelled recharge is
physically sound and it is in line with the overall determination of recharge in semi-arid
areas by a range of methods.
The soil water balance model was utilised to explore important aspects of recharge in
semi-arid regions showing the effect of the field variability on the model's output. The
preliminary results show that the developed concept reasonably represents the inherent
field variability, thus corroborating the strength of the approach for recharge estimation
in semi-arid regions
The Value of Cooperation: Studies on the Performance Outcomes of Interorganizational Alliances.
No full textStrategic alliances have gradually emerged over the last decades as a primary vehicle for corporate growth. Firms increasingly use strategic alliances to enter new markets, develop new products and obtain access to relevant knowledge and technological capabilities. Hoewever, while alliances can promote growth and create value they can also destroy it. The prevalence of alliances coupled with the considerable variation in their success rates has led to an increased effort by both scholars and practitioners to find out whether firms benefit from emerging alliances and what makes for a succesful alliance. Yet, despite the large number of studies conducted to date, past empirical research provides no consensus on (a) whether on average, firms benefit from entering alliances, (b) why some alliances create more firm value than others, and (c) the determinants of the performance of alliances themselves. Research presented in this dissertation uses meta-analysis to address these questions and obtain firm empirical generalizations on the performance outcomes of strategic alliances.
Foreign Direct Investment and Trade in the Southern African Development Community
No full textWe use a modified gravity model to estimate the relationship between trade and foreign direct investment (FDI) in the Southern African Development Community (SADC). We find evidence of a significant causal relationship from SADC?s exports to inward FDI. Distance (reflecting remoteness and transport costs) and political instability are confirmed to be significant determinants of FDI to SADC. We discern differences in the patterns and determinants of FDI to SADC, whether it is from the USA and UK or from continental Europe. In the case of FDI to SADC from the USA and UK, it is exports from SADC to these countries that are significant, and not imports, while, in the case of continental Europe, both exports and imports are significantly associated with FDI to SADC.FDI, SADC, South Africa, exports, gravity model
