98 research outputs found
Semantic-based Process Mining and Analysis
No full textSemantic-based Process Mining and AnalysisWhat is it about?The work in this research proves that semantic-based process mining and analysis is a useful technique especially in solving some didactic issues and answering some questions with regards to ontology-based methods for automatic discovery of different patterns or behaviours within any given process domain.Why is it important?The work extracts streams of event logs from a any given process execution environment and then describe formats that allows for abstract mining and improved process analysis of the captured data sets and models. Technically, the method makes use of semantic annotations, or better still, process description languages to link elements within the events log and model (e.g. using the case study of the research learning process) with concepts that they represent in an ontology specifically designed for representing the process.
Dr Kingsley Okoye (Author) University of East London
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An examination of the non-literal Exegesis in Genesis 1 - 11 in the Pseudo-Jonathan Targum
No full textSIGLEAvailable from British Library Document Supply Centre- DSC:D181048 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
Modulation of mitochondrial site-specific hydrogen peroxide efflux by exogenous stressors
No full textOxygen (O2) deprivation and metals are common environmental stressors and their exposure to aquatic organisms can induce oxidative stress by disrupting cellular reactive oxygen species (ROS) homeostasis. Mitochondria are a major source of ROS in the cell wherein a dozen sites located on enzymes of the electron transport system (ETS) and substrate oxidation produce superoxide anion radicals (O2˙¯) or hydrogen peroxide (H2O2). Sites located on ETS enzymes can generate ROS by forward electron transfer (FET) and reverse electron transfer (RET) reactions; however, knowledge of how exogenous stressors modulate site-specific ROS production is limited. We investigated the effects of anoxia-reoxygenation and cadmium (Cd) on H2O2 emission in fish liver mitochondria oxidizing glutamate-malate, succinate or palmitoylcarnitine-malate. We find that anoxia-reoxygenation attenuates H2O2 emission while the effect of Cd depends on the substrate, with monotonic responses for glutamate-malate and palmitoylcarnitine-malate, and a biphasic response for succinate. Anoxia-reoxygenation exerts a substrate-dependent inhibition of mitochondrial respiration which is more severe with palmitoylcarnitine-malate compared with succinate or glutamate-malate. Additionally, specific mitochondrial ROS-emitting sites were sequestered using blockers of electron transfer and the effects of anoxia-reoxygenation and Cd on H2O2 emission were evaluated. Here, we find that site-specific H2O2 emission capacities depend on the substrate and the direction of electron flow. Moreover, anoxia-reoxygenation alters site-specific H2O2 emission rates during succinate and glutamate-malate oxidation whereas Cd imposes monotonic or biphasic H2O2 emission responses depending on the substrate and site. Contrary to our expectation, anoxia-reoxygenation blunts the effect of Cd. These results suggest that the effect of exogenous stressors on mitochondrial oxidant production is governed by their impact on energy conversion reactions and mitochondrial redox poise. Moreover, direct increased ROS production seemingly does not explain the increased adverse effects associated with combined exposure of aquatic organisms to Cd and low dissolved oxygen levels
Something Must be Wrong
No full textAn insightful, thought provoking work about the
nfused situation of things in the country. A
t te where corruption and bribery have eaten so
ep into the blood system of the natio~ that the
uthor is frequently exclaiming "something must
b wrong!"
"Something must be wrong" is also the title of the work, and when something is wrong, then solution is sought to put things right. Unfortunately, this is not the case in Nigeria. We em to have landed ourselves in a state where
the rats found themselves as they searched for a
way of controlling one of their greatest enemies - the cat. One solution was agreed by all the rats and that is, to bell the cat. But one rat asked, who will bell the tat? At this point, all the rats took to
their holes for none was ready to volunteer to bell
the cat. Cats remain the greatest enemy of rats till
ate. Have we landed ourselves in the same situation the rats found themselves?
vii
Titles like "The Logic of Self-destruction",
"The manslaughter of Education", "Chief-Omego-
Syndrome", "The Patriots of Doom", "The Holy
Thieves and the God of Bandits", "The Banks of
Bankruptcy", reflect the situation we described
above.
The last two chapters, however, insist that
Nigerians as whole' should join hands to fight
undignified, dishonourable and disrespectful life
style. This is simply put by the author in this way,
"Nigerians repent"!"
This work is an eye-opener and is written
for all. It is simply presented in a way that even
elementary five pupils can understand. Other
attractive aspect of the work is that the author
makes use of stories and films we all know. He is,
simply put, an honest writer who does not take
hi r aders for granted; he tells us the source of
hi in piration.
Read and find out for yourself.
Anthony C. Okeke
Enugu, December 199
Factors affecting liver mitochondrial hydrogen peroxide emission
No full textMitochondria are key cellular sources of reactive oxygen species (ROS) and contain at least 12 known sites on multiple enzymes that convert molecular oxygen to superoxide and hydrogen peroxide (H2O2). Quantitation of site-specific ROS emission is critical to understand the relative contribution of different sites and the pathophysiologic importance of mitochondrial ROS. However, factors that affect mitochondrial ROS emission are not well understood. We characterized and optimized conditions for maximal total and site-specific H2O2 emission during oxidation of standard substrates and probed the source of the high H2O2 emission in unenergized rainbow trout liver mitochondria. We found that mitochondrial H2O2 emission capacity depended on the substrate being oxidized, mitochondrial protein concentration, and composition of the ROS detection system. Contrary to our expectation, addition of exogenous superoxide dismutase reduced H2O2 emission. Titration of conventional mitochondrial electron transfer system (ETS) inhibitors over a range of conditions revealed that one size does not fit all; inhibitor concentrations evoking maximal responses varied with substrate and were moderated by the presence of other inhibitors. Moreover, the efficacy of suppressors of electron leak (S1QEL1.1 and S3QEL2) was low and depended on the substrate being oxidized. We found that H2O2 emission in unenergized rainbow trout liver mitochondria was suppressed by GKT136901 suggesting that it is associated with NADPH oxidase activity. We conclude that optimization of assay conditions is critical for quantitation of maximal H2O2 emission and would facilitate more valid comparisons of mitochondrial total and site-specific H2O2 emission capacities between studies, tissues, and species
Effects of substituting fish meal with grasshopper meal on growth and food utilization of the Nile Tilapia, Oreochromis niloticus fingerlings
No full textThe effects of substituting fish meal with grasshopper meal in fish diets on the growth, food utilization and survival of the Nile tilapia, Oreochromis niloticus (mean weight = 40.1g) were investigated. The results show that the best growth and food utilization were recorded in the fingerlings fed in the 10% grasshopper meal and 30% fish meal while the poorest growth and food utilization indexes were recorded with the 25% grasshopper meal and 15% fish meal. In general, at 10% inclusion, the fingerlings performed even better than the control (40% fishmeal and no grasshopper meal
Anoxia-reoxygenation modulates cadmium-induced liver mitochondrial reactive oxygen species emission during oxidation of glycerol 3-phosphate
No full textAquatic organisms are frequently exposed to multiple stressors including low dissolved oxygen (O2) and metals such as cadmium (Cd). Reduced O2 concentration and Cd exposure alter cellular function in part by impairing energy metabolism and dysregulating reactive oxygen species (ROS) homeostasis. However, little is known about the role of mitochondrial glycerol 3-phosphate dehydrogenase (mGPDH) in ROS homeostasis in fish and its response to environmental stress. In this study, mGPDH activity and the effects of anoxia-reoxygenation (A-RO) and Cd on ROS (as hydrogen peroxide, H2O2) emission in rainbow trout liver mitochondria during oxidation of glycerol 3-phosphate (G3P) were probed. Trout liver mitochondria exhibited low mGPDH activity that supported a low respiratory rate but substantial H2O2 emission rate. Cd evoked a low concentration stimulatory-high concentration inhibitory H2O2 emission pattern that was blunted by A-RO. At specific redox centers, Cd suppressed H2O2 emission from site IQ, but stimulated emission from sites IIIQo and GQ. In contrast, A-RO stimulated H2O2 emission from site IQ following 15 min exposure and augmented Cd-stimulated emission from site IIF after 30 min exposure but did not alter the rate of H2O2 emission from sites IIIQo and GQ. Additionally, Cd neither altered the activities of catalase, glutathione peroxidase, or thioredoxin reductase nor the concentrations of total glutathione, reduced glutathione, or oxidized glutathione. Overall, this study indicates that oxidation of G3P drives ROS production from mGPDH and complexes I, II and III, whereas Cd directly modulates redox sites but not antioxidant defense systems to alter mitochondrial H2O2 emission
PRODUCTION AND EVALUATION OF PROTEIN QUALITY OF BREAD FROM WHEAT / COWPEA FLOUR BLENDS.
No full textThe protein quality of bread samples produced from wheat and cowpea flour blends was investigated. The wheat flour (WF) was composite with cowpea flour (CF) at the levels of 10%, 20%, 30% and 40% and used for bread production. The samples of bread produced were later sliced, dried and milled systematically into bread flours. The resulting bread flours were individually formulated into test diets whereas the casein based diet was similarly formulated and used as control. After formulation, the protein quality of the test diets and the control were evaluated using the protein efficiency ratio index with thirty-five weanling albino rats. The rats which were six weeks old and weighing between 42.3 and 44.1 grammas were divided into five groups of seven rats each and housed in individual metabolic cages; fed diets and tap water adlibitum for a period of 21 days. From the results, the corrected protein efficiency ratio (PER) of casein based diet was 2 .5 and those of the test diets formulated from bread were 2.18, 2.23, 2.30 and 2.32 respectively. However, the values of the correct protein efficiency ratio of the bread formulated diets were generally lower than that of the casein based diet irrespective of the level of fortification of the bread samples with cowpea flour
Toxicity of heavy metals to fish: an important consideration for sucessful aquaculture
Full text linkHeavy metals are toxic to man, animals and plants once safe limits are exceeded. Then ability to bio accumulate in plant and animal tissues makes them particularly hazardous. Heavy metals are toxic to all aquatic biota and cause high mortality of fish larva, fry, fingerling and adult fish. They accumulate in the gills, heart, liver, kidneys, brain, bones and muscles of fish. The physico-chemical forms of heavy metals determine their mobility, availability and toxicity to fish. These metals enter aquaculture systems through various means (polluted water, storage facilities, fish feed, atmospheric deposition, etc) and constitute a factor detrimental to successful aquaculture. This paper reviews the mode of entry, transport and toxicity of some selected heavy metals to freshwater fish. Methods for the determination of these metals in water, fish and sediment samples are also presented. Ways of preventing their entry into aquaculture systems together with the safe limits of concentration of these metals in aquaculture systems are also included
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