261 research outputs found
COLLECTIVE EFFECTS IN THE DESORPTION PROCESS INDUCED BY Hn+ CLUSTERS NEAR THE BOHR'S VELOCITY
The emission yield of the positive ions Cs+ and H+ from CsI bombarded by 600 keV Hn+ clusters, has been correlated with the energy deposited by these particles. Above the BOHR'S velocity, vo, the concept of equipartition between close and distant collisions could apply while below vo, collective effects are still observed (distant collisions). The same power relationship between the emission yield and an "efficent" mean stopping power for the cluster is pointed out within the whole investigated velocity range
Fault Analysis of Injection SubstationUsing Symmetrical Component MethodA Case Study of Mofor Injection Substation, Delta State, Nigeria
This study centers on the fault analysis of 15MVA Mofor Injection Substation, which is an Injection Substation located in Warri, Delta state, Nigeriawhich gets its source from PTI transmission station. Mofor Injection substation has two outgoing feeders which are Orhuwhorun feeder and Ekete feeder. The analysis was carried out and deductions were made considering the various faults which occurred during the period of assessment and their associated fault current was calculated using symmetrical Component method of Fault analysis. Amodel of the distribution network was made using Electrical Transient Analyzer Program(ETAP); the value of real and reactive powers and voltage magnitudes in the whole network wereobserved. Thedata obtained from the injection substation indicates that Orhuwhorun feeder has a higher frequency of fault and from results obtained from Symmetrical method of fault analysis revealed that double Line to ground fault has the highest fault current and could cause adverse damages to equipments’and as such must be avoided. The fault current calculated from Symmetrical component method of Fault analysis was validated with computer program MATLAB as results agreed closely since error was below 0.1%.This paper analyzes several faults from an injection substation. The distribution network was modelled in ETAP, observing values for active and reactive power and voltage magnitude
Implanted Pacemaker Regarding to Complete Atrioventricular Block : a Case Report
Scientific advisers: assis. prof. M.V. Pochinskaya, prof. M. I. Yabluchanski
Biopolymer-mediated Green Synthesis of Noble Metal Nanostructures
Polymer-coated noble metal nanoparticles are currently of particular interest to investigators in the fields of nanobiomedicine and fundamental biomaterials. These materials not only exhibit imaging properties in response to stimuli but also efficiently deliver various drugs and therapeutic genes. Even though a large number of polymer-coated noble metal nanoparticles have been fabricated over the past decade, most of these materials still present some challenges emanating from their synthesis. The metal nanoparticles when encapsulated in a polymer and taken up by human cells might show a lower degree of toxicity; however, the degree of toxicity for some of the starting materials and precursors has raised serious concerns. Hence, there is a need to implement the principle of green chemistry in the synthesis of nanomaterials. The use of environmentally benign materials for the synthesis of metal nanoparticles provides numerous benefits ranging from biocompatibility, availability, cost-effectiveness, amenable scale-up to eco-friendliness. The biopolymer-based nanovehicles have been found to be more suitable in the field of nanotechnology owing to their high reproducibility, ease of manufacture, functional modification and safety (they are not carcinogenic). Unlike synthetic polymers where the raw material can be derived from petrochemicals or chemical industrial processes, biopolymers are produced from renewable resources such as plant and/or living organism. They are degradable by natural processes down to elemental entities that can be resorbed in the environment. Furthermore, they can also be modified to serve a particular purpose which explains the myriad of their potential applications. The macromolecular chain of these biopolymers possesses a large number of hydroxyl groups which can easily complex with metal ions. Additionally, these biopolymers also contain supramolecular structures that can lead to new functionalities of their composites with metal and semiconductor nanoparticles. In this chapter, a comprehensive discussion on different biopolymers, green synthesis of noble metal nanostructures, mechanisms, characterization and application in various fields is presented
Estimation of Human Health Risk Due to Heavy Metals around Schools and Auto-Mobile Workshops near Frequented Roads in Kaduna State, Nigeria
Heavy metals are widely known for their potential to cause carcinogenic and non-carcinogenic health risks. In this work, the carcinogenic and non-carcinogenic health risks associated with heavy metals in the vicinity of schools and auto mechanic workshops close to busy roads in Kaduna state was assessed using NEX CG EDXRF MODEL with brand name RIGAKU situated at a UTM Laboratory, Malaysia. The obtained heavy metals concentrations were used to estimate the health effects that might result from exposure to carcinogenic and non-carcinogenic chemicals for both the population ages using US EPA methodology. Findings indicated that in some locations the carcinogenic and non-carcinogenic hazards associated with exposure for residents was greater than the US EPA acceptable thresholds of 10-4 and 1 respectively. This indicated that the heavy metals may result to unacceptable carcinogenic and non-carcinogenic risks, which is an issue of concern in public health especially looking at the way school children play around these areas. The present study therefore provides scientific basis for strategies required to protect human and environmental health in schools and automobile workshops
Evidence of Heavy Metals Distribution in Placenta in Association with Residual Levels in Some Dams’ Organs from Bodija abattoir, Oyo State, Nigeria
Heavy metals have been known to be causing serious detrimental effect on the health of livestock and human populace in general. However, little study had been carried out on the ability of heavy metal to cross placental barrier, which has already been bio-accumulated in the dam. Therefore, this study aimed at showing the evidence of placental barrier crossing by selected heavy metals. The study was carried out in Bodija abattoir, Ibadan, Oyo-state, Nigeria, located on latitude 70020N, longitude 3005E. A cross-sectional study design was adopted and lasted for 6 weeks. Samples were collected from kidney cortices, apical lobe of dam’s liver and a portion of fetal placenta. 12 sample each from liver, kidney and the placenta which were analyzed using Atomic Absorption Spectrophotometer (AAS). Results were subjected to descriptive statistics, t-test and correlation using SPSS17.0 package.From this study cadmium (Cd) and lead (Pb) residues were not found in the samples, while chromium (Cr) was found in all the samples (100% prevalence) and the total prevalence for the heavy metals in the study was 33.4%. The mean chromium (Cr) residual values in placenta, kidney and liver were 0.89±0.66mg/kg, 1.32±0.94mg/kg and 1.00±0.87 mg/kg respectively. The correlation between chromium (Cr) in the dam’s kidney and placenta was 0.3, while for the dam’s liver and placenta was 0.6. In comparison with permissible limit, the residual level in kidney 1.32±0.94, liver 1.00±0.87 and placenta 0.89±0.66, were within the permissible limit. The study revealed that chromium (Cr) residue was a major challenge in the organs sampled. Liver of the dam had the highest level of bioaccumulation and stronger correlation in the distribution to the placenta. It is therefore recommended that attention should be paid on the disposal of chromium (Cr) residues on the grazing floor where the bulk of the residues were from. Keywords: Heavy metals, Liver, Kidney, Placenta and cattle
CRIME RATE PREDICTION USING THE RANDOM FOREST ALGORITHM
An act that creates crimes punishable by law is characterized as a crime. Rape, fraud, terrorism, kidnapping, burglary, murder, and other crimes are common in Nigeria. Examples are cybercrime, bribery and corruption, robbery, money laundering, among other crimes. Crime is a harmful and widespread social issue that affects individuals all around the world. The rate of crime has risen dramatically in recent years. To cut down on crime, at any rate, law enforcements must take preventative actions. To protect society against crime, modern systems and new technologies are required. Although accurate real-time crime study is on aid in reducing crime rates, they are nonetheless useless. As crime occurrences are dependent on, this is a difficult subject for the scientific community to solve. Therefore, this paper proposes machine learning algorithm to indicate the frequency and pattern of crimes based on the data collected and to show the extent of crime in a particular region. Various visualization approaches and machine learning algorithms are used in this study to anticipate the crime distribution over a large area. In the first stage, raw datasets were processed and visualized according to the requirements. Then, to extract knowledge from these massive datasets, machine learning methods were deployed and uncover hidden patterns in the data, which were then utilized to investigate and report on crime patterns, It is beneficial to crime analysts. Investigate these crime networks using a variety of interactive crime visualizations. As a result, it is helpful in crime prevention
Value relevance of financial statements and share price: a study of listed banks in Nigeria
This paper examined the effects of value relevance of financial statements on firms share price in Nigeria. In achieving the objectives of this research, the fact book from the Nigerian Stock Exchange Market and the audited financial statement of listed banks spanning the period 2010-2014 were used. Also, a total of 15 listed banks in the Nigerian stock exchange market were selected and analyzed for the study using the purposive sampling method. However, in analyzing the research hypotheses, the study adopted the use of both descriptive statistics and the use of Fixed Effects Panel data method of data analysis technique. Findings from the study showed that a significant positive relationship existed between earnings per share (EPS) and Last day share price (LDSP). The study recommends the need for banks in the country to improve on the quality of earnings reported, since it has a stronger ability to explaining share prices of firm
A spontaneous increase in intracellular Ca2+ in metaphase II human oocytes in vitro can be prevented by drugs targeting ATP-sensitive K+ channels
STUDY QUESTION: Could drugs targeting ATP-sensitive K+ (KATP) channels prevent any spontaneous increase in intracellular Ca2+ that may occur in human metaphase II (MII) oocytes under in vitro conditions? SUMMARY ANSWER: Pinacidil, a KATP channel opener, and glibenclamide, a KATP channel blocker, prevent a spontaneous increase in intracellular Ca2+ in human MII oocytes. WHAT IS KNOWN ALREADY: The quality of the oocyte and maintenance of this quality during in vitro processing in the assisted reproductive technology (ART) laboratory is of critical importance to successful embryo development and a healthy live birth. Maintenance of Ca2+ homeostasis is crucial for cell wellbeing and increased intracellular Ca2+ levels is a well-established indicator of cell stress. STUDY DESIGN, SIZE, DURATION: Supernumerary human oocytes (n = 102) collected during IVF/ICSI treatment that failed to fertilize were used from October 2013 to July 2015. All experiments were performed on mature (MII) oocytes. Dynamics of intracellular Ca2+ levels were monitored in oocytes in the following experimental groups: (i) Control, (ii) Dimethyl sulfoxide (DMSO; used to dissolve pinacidil, glibenclamide and 2,4-Dinitrophenol (DNP)), (iii) Pinacidil, (iv) Glibenclamide, (v) DNP: an inhibitor of oxidative phosphorylation, (vi) Pinacidil and DNP and (vii) Glibenclamide and DNP. PARTICIPANTS/MATERIALS/SETTINGS/METHODS: Oocytes were collected under sedation as part of routine treatment at an assisted conception unit from healthy women (mean ± SD) age 34.1 ± 0.6 years, n = 41. Those surplus to clinical use were donated for research. Oocytes were loaded with Fluo-3 Ca2+-sensitive dye, and monitored by laser confocal microscopy for 2 h at 10 min intervals. Time between oocyte collection and start of Ca2+ monitoring was 80.4 ± 2.1 h. MAIN RESULTS AND THE ROLE OF CHANCE: Intracellular levels of Ca2+ increased under in vitro conditions with no deliberate challenge, as shown by Fluo-3 fluorescence increasing from 61.0 ± 11.8 AU (AU = arbitrary units; n = 23) to 91.8 ± 14.0 AU (n = 19; P <0.001) after 2 h of monitoring. Pinacidil (100 µM) inhibited this increase in Ca2+ (85.3 ± 12.3 AU at the beginning of the experiment, 81.7 ± 11.0 AU at the end of the experiment; n = 13; P = 0.616). Glibenclamide (100 µM) also inhibited the increase in Ca2+ (74.7 ± 10.6 AU at the beginning and 71.8 ± 10.9 AU at the end of the experiment; n = 13; P = 0.851. DNP (100 mM) induced an increase in intracellular Ca2+ that was inhibited by glibenclamide (100 µM; n = 9) but not by pinacidil (100 µM; n = 5). LIMITATIONS, REASONS FOR CAUTION: Owing to clinical and ethical considerations, it was not possible to monitor Ca2+ in MII oocytes immediately after retrieval. MII oocytes were available for our experimentation only after unsuccessful IVF or ICSI, which was, on average, 80.4 ± 2.1 h (n = 102 oocytes) after the moment of retrieval. As the MII oocytes used here were those that were not successfully fertilized, it is possible that they may have been abnormal with impaired Ca2+ homeostasis and, furthermore, the altered Ca2+ homeostasis might have been associated solely with the protracted incubation. WIDER IMPLICATIONS OF THE FINDINGS: These results show that maintenance of oocytes under in vitro conditions is associated with intracellular increase in Ca2+, which can be counteracted by drugs targeting KATP channels. As Ca2+ homeostasis is crucial for contributing to a successful outcome of ART, these results suggest that KATP channel openers and blockers should be tested as drugs for improving success rates of ART
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