307 research outputs found
Numerical Computation of Electric Field and Charge Structure of a Typical Tropical Thunderstorm
Cloud charge dynamics are usually determined from ground measurements. Where in-situ cloud measurements are available they sometimes modify the cloud structure; and this can be expensive, and merely diagnostic at best. In this work, Poisson integral formula is simplified by adapting the Bessel functions to obtain the cascaded potential gradients at any point on ground as a result of charge distribution in cylindrical volumes. The model represents the cloud charges as a vertical sequence of axially aligned, uniformly-charged densities of cylindrical disk(slices), The resulting expressions for the potential gradient is solved numerically as a functions of normalized vertical and horizontal distances to model the vertical electric field and potential profiles below a typical thunderstorm. Keywords: Electric field, Bessel functions, Charge structure, Cylindrical charge model, Lower positive charge center
Numerical Simulation of Electric Field and Charge Structure within an Isolated Thunderstorm
The study of electrical structure of thunderstorm is a deterministic factor in characterizing the behavior of lightning. It is impossible to measure the value of electric field at every point within the thunderstorm, even when the in situ measurements are made, they are done along the path of balloon-borne instruments or other methods employed in the measurement. The average data obtained from past measurements were employed in determining the electric field generated by the thunderstorm as observed along the horizontal distance using the cylindrical charge model. The data consisted of a screening charge layer firstly located “between” 1.8-2.0 km and later between 10.0-10.2 km respectively above the ground level (agl) to see the effect of positioning on the resultant computation. The lower positive charge center with radius ranging from 0.5 km to 2.0 km was placed at various heights between 2.0 and 6.0 km. This is to determine the effect of cloud base height on the resulting field profile. The main negative charge is accommodated between 4.0 and 7.5 km and the upper positive charge layer existed between 7.5- 10.0 km agl for a cloud base height of 2.0 km and 6.0- 9.5 km agl for a negative charge layer, 7.5- 11.0 km agl for upper positive charge with a cloud base of 4.0 km high. The resulting potential gradient (PG) profiles were obtained for spatial distribution with screening charge layer playing no active role in the thunderstorm electrification. The effects of wind shear due to increasing wind speed with height were also investigated to have a clear picture of the cloud charge dynamics; hence the vertical PG patterns produced by a moving thunderstorm for various cloud cell life-times were modeled. The results showed that a typical tropical thunderstorm can exhibit charge layer more than the normal tripolar structure, and the pocket of lower positive charge can be more than one or larger than the usual size. Wind shear was found to enhance lightning discharges at the surface of charge discontinuities. Keywords: Potential gradient, Wind shear, Cloud charge, Lower positive charge center, Noninductive charging.
Effects of Cissus Populnea on the Rheological Properties of Local Clay
Globally, Wyoming bentonite has been observed as the only accepted drilling fluid. Hence, the importance of investigating the mode by which Cissus populnea affects the rheological properties of local clay and as possible substitute for the international standard clay as drilling fluid. Ten samples of the local mud were taken at different locations of Afuze deposit, the stem bark of Cissus populnea was purchased in Ekiti State and authenticated at the herbarium, University of Ibadan, Nigeria. Its extraction was effected using the soxhlet extractor apparatus. Samples A and C, were respectively the mud of the local clay and a mixture of the Cissus populnea extract and the local clay. A control sample, B was formed from a mixture of water and the International Standard Wyoming bentonite which was obtained from the Petroleum Engineering Department of the University of Ibadan. Rheological properties of each of the samples were determined. The results of sample C (density (9.85 lb/gal), pH (9.9–11.3); funnel viscosity (50–62 seconds); hydroxylethyl cellulose at 600 rpm (22-38 cp); filtrate value (13.0–15.8 ml); sand content (0.50–0.81ppg); gel strength (15-21 lb/100ft2) and yield stress (7-13 lb/100ft2)) fell within the API RP–13B standard for drilling fluid. The analysis showed that the differences between samples A, B and C were negligible and that the local clay treated with Cissus populnea can serve as a substitute for foreign clay
Phytopharmacotherapeutic and Antimicrobial Attributes of Bitter Apple (Citrullus colocynthis) - A Review
Emergence of drug-resistant microorganisms over the past few decades has resulted in the search for bioactive compounds potent against these microorganisms. Phytochemicals derived from plants have shown positive curative properties and can be extracted from any part of the plant such as the roots, stem or flower. Bitter apple (Citrullus colocynthis) has been used traditionally for the treatment of infectious diseases and this has stimulated pharmacological interest in the active ingredients responsible for its medicinal properties. The plant also possesses several biological and pharmacological activities including anti-inflammatory, antidiabetic, antimicrobial, anticancer, and antioxidant. This review discussed the phytochemicals present in C. colocynthis, their mode of action and their antimicrobial attributes
Can I get a witness?
Background\ud
The effect of family presence during cardiopulmonary resuscitation (CPR) on family members and the medical team remains controversial.\ud
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Methods\ud
The authors enrolled 570 relatives of active cardiac arrest patients receiving CPR by 15 pre-hospital emergency medical service units. The units were randomly assigned either to systematically offer the family member the opportunity to observe CPR (intervention group) or to follow standard practice regarding family presence (control group).\ud
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Objective: The primary end point was the proportion of relatives with post-traumatic stress disorder (PTSD)-related symptoms at 90 days. Secondary end points included the presence of anxiety and depression symptoms and the effect of family presence on medical efforts at resuscitation, the well being of the healthcare team, and the occurrence of medicolegal claims.\ud
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Design: Prospective cluster-randomized controlled trial.\ud
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Setting: Emergency medical service units were deployed to areas of the city across all socioeconomic groups in France from November 2009 to October 2011.\ud
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Subjects: Adult family members of adult patients in cardiac arrest occurring at home. Only one first-degree relative per patient was evaluated. The relative was chosen in accordance with the legislation on hospitalization at the request of a third party in the following order of preference: spouse, parent, offspring, sibling. Exclusion criteria were communication barriers with the relative and cardiac arrest cases in which resuscitation was not attempted.\ud
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Intervention: For emergency medical service units assigned to the intervention, a medical team member systematically asked family members whether they wished to be present during the resuscitation. A communication guide helped introduce the relative to the resuscitation scene and, when required, to help with the announcement of the death.\ud
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Results\ud
In the intervention group, 211 of 266 relatives (79%) witnessed CPR, compared with 131 of 304 relatives (43%) in the control group. In the intention-to-treat analysis, the frequency of PTSD-related symptoms was significantly higher in the control group than in the intervention group (adjusted odds ratio, 1.7; 95% confidence interval (CI), 1.2 to 2.5; P =0.004) and among family members who did not witness CPR than among those who did (adjusted odds ratio, 1.6; 95% CI, 1.1 to 2.5; P =0.02). Relatives who did not witness CPR had symptoms of anxiety and depression more frequently than those who did witness CPR. Family-witnessed CPR did not affect resuscitation characteristics, patient survival, the level of emotional stress in the medical team, and did not result in medicolegal claims.\ud
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Conclusions\ud
Family presence during CPR was associated with positive results on psychological variables of family members and did not interfere with medical efforts, cause increased stress in the healthcare team or result in medicolegal conflicts
Phytopharmacotherapeutic and Antimicrobial Attributes of Bitter Apple (Citrullus colocynthis) - A Review
Emergence of drug-resistant microorganisms over the past few decades has resulted in the search for bioactive compounds potent against these microorganisms. Phytochemicals derived from plants have shown positive curative properties and can be extracted from any part of the plant such as the roots, stem or flower. Bitter apple (Citrullus colocynthis) has been used traditionally for the treatment of infectious diseases and this has stimulated pharmacological interest in the active ingredients responsible for its medicinal properties. The plant also possesses several biological and pharmacological activities including anti-inflammatory, antidiabetic, antimicrobial, anticancer, and antioxidant. This review discussed the phytochemicals present in C. colocynthis, their mode of action and their antimicrobial attributes
Evaluation of the comparative efficacy and safety of artemether-lumefantrine, artesunate-amodiaquine and artesunate-amodiaquine-chlorpheniramine (Artemoclo™) for the treatment of acute uncomplicated malaria in Nigerian children.
OBJECTIVE: To evaluate the comparative efficacy and safety of artemether-lumefantrine (AL), artesunate-amodiaquine (ASAQ) and artesunate-amodiaquine-chlorpheniramine (AQC) for the treatment of acute uncomplicated malaria among Southwest Nigerian children. SUBJECTS AND METHODS: One hundred and sixty children aged 6 months to 14 years with acute uncomplicated malaria were randomized to AL (n = 53), ASAQ (n = 53), or AQC (n = 54). Enrollees were seen daily on days 0-3 and then on days 7, 14, 21, 28 and 42 for clinical and parasitological evaluations. Paired samples of genomic DNA at enrolment and at the time of recurrent parasitaemia were genotyped using nested PCR to distinguish between reinfection and recrudescence. Detailed haematological and biochemical evaluations were carried out in a subset of enrollees on days 0, 7 and 28 as part of a safety evaluation. RESULTS: Of the 160 children, 144 (90%) completed the study. The mean fever clearance times and parasite clearance times for AL, ASAQ and AQC were comparable (p = 0.94 and p = 0.122, respectively). On day 14, the adequate clinical and parasitological response (ACPR) for AL and AQC was 100% and for ASAQ it was 90% (p = 0.39). The PCR-uncorrected results on days 28 and 42 and the ACPR-corrected results on day 42 were similar for all drugs (p = 0.62 and p = 0.56, respectively). AQC resulted in the best parasite clearance and haematological recovery on day 2 (p = 0.022 and p = 0.018, respectively). Biochemical parameters were not adversely affected by the three artemisinin-based combination therapies (ACTs) and these were well tolerated. CONCLUSION: The three ACTs were efficacious and safe, but AQC resulted in a better haematological recovery on day 2 and higher cure rates throughout the study period
Nutrient composition of watermelon (Citrullis lanatus (Thunb.) Matsum.&Nakai) and egusi melon (Citrullus colocynthis (L.) Schrad.) seeds
This study investigated the nutrient composition of the seeds of two cultivars of Citrullis lanatus (\u27Rhotmas\u27 and \u27Sugar Baby\u27) and compared it with Citrullus colocynthis. The moisture content, ash, crude fiber, ether extract, crude protein and true protein ranged from 5.43 to 6.82, 2.78 to 3.72, 1.66 to 3.94, 55.7 to 58.7, 19.16 to 25.18 and 10.8 to 13%, respectively. The starch content, total sugar and reducing sugar varied between 143.7 and 172.7, 53.7 and 96.5, 5.6 and 9.5 mg/g, respectively. Iron, copper, zinc, calcium and magnesium ranged from 191 to 211, 20.12 to 35.03, 68.97 to 92.57, 98.79 to 233, and 79.75 to 123.9 mg/kg, respectively. Heavy metals (lead and cadmium) and antinutrients (phytate, oxalate and cyanide) were below deleterious levels. Arginine, glutamic acid and aspartic acids were the most abundant amino acids, whereas lysine was the limiting amino acid. It is concluded that watermelon seeds were better in nutritional value compared to egusi melon seeds and therefore could be regarded as a potential sources of food if exploited
Perception of community pharmacists on abuse of psychotropic medications among the consumers
Purpose: Abuse of medications implies that the user is using them for reasons other than those indicated in the prescribing literature. Psychotropic medications are those capable of affecting the mind, motions, and behavior of humans. This study sought to determine the perception of community pharmacists about the pattern of psychotropic medication abuse among their customers.Methods: A descriptive, cross-sectional study carried out among community pharmacists in Surulere axis of Lagos State, Nigeria, by census sampling method using a structured questionnaire.Results: Majority of the respondents (74.7%) were male and within ten years of practice experience (85.1%). About four-fifth (84.4%) of the respondents perceived that psychotropic medications were being abused by customers purchasing such medications from them. Caffeine-based analgesics ranked highest (85.1%) among the drugs perceived to be abused while dextromethorphan-containing cough syrup, sedative antihistamine, codeine-based analgesics, tramadol, oral decongestant, and benzodiazepines were perceived to be equally abused (84.4%). Male customers were perceived to abuse psychotropic medications more than their female counterparts and abuse of tramadol and codeine-based analgesics were specifically noted to be higher in customers younger than 26 years of age.Conclusion: Consumer psychotropic medication abuse at community pharmacies was perceived to be ignificant in Lagos community pharmacies
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