Phase synchronization between tropospheric radio refractivity and rainfall amount in a tropical region

This study investigated linear and nonlinear relationship between the amount of rainfall and radio refractivity in a tropical country, Nigeria using forty seven locations scattered across the country. Correlation and Phase synchronization measures were used for the linear and nonlinear relationship respectively. Weak correlation and phase synchronization was observed between seasonal mean rainfall amount and radio refractivity while strong phase synchronization was found for the detrended data suggesting similar underlying dynamics between rainfall amount and radio refractivity. Causation between rainfall and radio refractivity in a tropical location was studied using Granger causality test. In most of the Southern locations, rainfall was found to Granger cause radio refractivity. Furthermore, it was observed that there is strong correlation between mean rainfall amount and the phase synchronization index over Nigeria. Coupling between rainfall and radio refractivity has been found to be due to water vapour in the atmosphere. Frequency planning and budgeting for microwave propagation during periods of high rainfall should take into consideration this nonlinear relationship

Investigating chaotic features in solar radiation over a tropical station using recurrence quantification analysis

The use of solar energy for power generation and other uses is on the increase. This demand necessitate a better understanding of the underlying dynamics for better prediction. Nonlinear dynamics and its associated tools readily lend itself for such analysis. In this paper, nonlinearity in solar radiation data is tested using recurrence plot (RP) and recurrence quantification analysis (RQA) in a tropical station. The data used was obtained from an ongoing campaign at the Federal University of Technology, Akure, Southwestern Nigeria using an Integrated Sensor Suite (Vantage2 Pro). Half hourly and daily values were tested for each month of the year. Both were found to be nonlinear. The dry months of the year exhibit higher chaoticity compared to the wet months of the year. The daily average values were found to be mildly chaotic. Using RQA, features due to external effects such as harmattan and intertropical discontinuity (ITD) on solar radiation data were uniquely identified

Prevalence and correlates of psychiatric morbidity among caregivers of children and adolescents with neuropsychiatric disorders in Nigeria

Objective: To screen for psychiatric morbidity among caregivers of patients attending a child and adolescent psychiatric clinic. Method: A total of 155 patients and their caregivers were consecutively recruited over a 1 month period. Sociodemographic and clinical information on patients was obtained either from the hospital records or from the caregiver. Scoring on the Children’s Global Assessment Scale (CGAS) was done by clinicians. The caregivers were administered a sociodemographic questionnaire, GHQ-12, Zarit Burden interview, and the Columbia Impairment Scale. Results: Most caregivers observed in this study were females (80.5%) with mothers of the patients accounting for 78% of all the caregivers. A higher percentage of the patients were males (52.8%). Among the caregivers, 39.4% had GHQ Scores of 3 and above. Factors associated with psychiatric morbidity among caregivers include the high level of subjective burden of care, low level of functioning, high degree of impairment and low level of education among patients. Conclusion: The study reveals a high level of psychiatric morbidity among the carers of children and adolescents with mental health problems.Keywords: Psychiatric morbidity; Care giver; Children and adolescent

Management of erectile dysfunction: perceptions and practices of Nigerian primary care clinicians

Erectile dysfunction (ED) is a prevalent health problem in many societies, but the diagnosis is seldom documented in primary care. The objective of this study was to investigate the perception and practices of clinicians regarding the management of ED in primary care settings in Nigeria. Methods A self-administered semi-structured questionnaire was applied to a purposive sample of clinicians attending conferences/workshops organised by the Society of Family Physicians of Nigeria and Update Courses of the Faculties of Family Medicine of the National Postgraduate Medical College of Nigeria and the West African College of Physicians. Information was obtained on their professional characteristics, experiences with the management of ED and possible barriers to the effective management of ED. Results A total of 187 completed questionnaires were analysed. Most (87.2%) of the respondents were general practitioners, while the rest were specialists in various fields (excluding sexual health) who worked at the primary care level. One hundred and forty-seven respondents (76%) reported that ED was common in their clinical practice. Over half (56.2%) of the respondents ascribed a high priority to ED management in their day-to-day clinical practice, while 33.2% and 10.6% of them ascribed medium and low priority to ED management respectively. Although 80.8% of the respondents agreed that ED patients could benefit from orthodox treatments, only 18% of them had ever prescribed any medication for affected patients; most (82%) of them either counselled or referred ED patients to secondary or tertiary care level for further management. Most of the clinicians (62%) would not take a sexual history unless the patient brought it up. The reported barriers to the management of ED include lack of a standardised protocol (64.2%), inadequate experience in ED management (85.6%), preference of patients for native medication (42.3%), and the high cost of modern medication (48.1%). Conclusion The clinicians acknowledged the high prevalence of ED in the primary care setting and recognised that they had a role to play in managing affected patients. The identified barriers to the management of the condition point to the need for education of both clinicians and patients, as well as the provision of guidelines for the management of ED in primary care settings.South African Family Practice Vol. 49 (9) 2007: pp. 1

Impact of Strategic Relationship Marketing on the Performance of Banks in Nigeria

The increasing patronage of non-bank institutions by customers exerts marketing pressure on the Nigerian commercial banks. Existing studies have not adequately addressed the gap created by this paradigm shift, hence the call for business philosophy that focuses on strategic relationship marketing (SRM) approach with the customers. Therefore, this study examines the influence of the SRM dimensions on customer retention of banks in Nigeria. The sample comprised 1500 commercial bank customers and marketing officers from 300 bank branches in Nigeria. Structured questionnaires were administered for data collection. Hierarchical regression model was fitted to the data collected. The findings revealed that strategic relationship marketing dimensions could lead to increased customer retention with adequate implementation of relationship acquisition strategy, and retention strategy. Further, inclusion of banking industry alignment strategy would make the banks to benefit maximally through customer linkage and also cause an optimal compensation or remedial system. The findings stressed the need for relationship acquisition, relationship maintenance and retention strategy as the strategic marketing tool to enhance customer retention of the banks. Keywords: strategic relationship, marketing, customer retention, banking industry alignment, banks DOI: 10.7176/JMCR/74-03 Publication date: December 31st 2020

Coherent Parton Showers with Local Recoils

We outline a new formalism for dipole-type parton showers which maintain exact energy-momentum conservation at each step of the evolution. Particular emphasis is put on the coherence properties, the level at which recoil effects do enter and the role of transverse momentum generation from initial state radiation. The formulated algorithm is shown to correctly incorporate coherence for soft gluon radiation. Furthermore, it is well suited for easing matching to next-to-leading order calculations.Comment: 24 pages, 3 figure

Screening nuclear field fluctuations in quantum dots for indistinguishable photon generation

A semiconductor quantum dot can generate highly coherent and indistinguishable single photons. However, intrinsic semiconductor dephasing mechanisms can reduce the visibility of two-photon interference. For an electron in a quantum dot, a fundamental dephasing process is the hyperfine interaction with the nuclear spin bath. Here we directly probe the consequence of the fluctuating nuclear spins on the elastic and inelastic scattered photon spectra from a resident electron in a single dot. We find the nuclear spin fluctuations lead to detuned Raman scattered photons which are distinguishable from both the elastic and incoherent components of the resonance fluorescence. This significantly reduces two-photon interference visibility. However, we demonstrate successful screening of the nuclear spin noise which enables the generation of coherent single photons that exhibit high visibility two-photon interference.Comment: 5 pages, 4 figures + Supplementary Informatio

A Positive-Weight Next-to-Leading-Order Monte Carlo for Heavy Flavour Hadroproduction

We present a next-to-leading order calculation of heavy flavour production in hadronic collisions that can be interfaced to shower Monte Carlo programs. The calculation is performed in the context of the POWHEG method. It is suitable for the computation of charm, bottom and top hadroproduction. In the case of top production, spin correlations in the decay products are taken into account.Comment: 18 pages, 12 figures. Few misprints corrected, references updated, final remarks adde

Single-top Wt-channel production matched with parton showers using the POWHEG method

We present results for the next-to-leading order calculation of single-top Wt-channel production interfaced to Shower Monte Carlo programs, implemented according to the POWHEG method. A comparison with MC@NLO is carried out. Results obtained using the PYTHIA shower are also shown and the effect of typical cuts is briefly discussed.Comment: 23 pages, 9 figure

Hemoglobin and ferritin concentrations in subjects with metabolic syndrome

Background Metabolic syndrome (MetS), a clinical condition characterized by insulin resistance, glucose intolerance, dyslipidemia, hypertension, and obesity, has been linked with raised levels of serum ferritin (Sfr) concentrations. Objectives This study was carried out to compare hemoglobin (Hb) and Sfr concentrations in patients with MetS, regular donors and first-time donors. Materials and Methods A total of 102 subjects who were between 18 and 60 years were enrolled for the study. They were divided into three groups. The first group (n = 20) was made up of 5 males and 15 females, all who met the criteria that define MetS. The second group (n = 52; M = 34, F = 18) were regular donors, while the last group (n = 30; M = 16, F = 14) were first-time donors or those who had not donated before. Following an overnight fast, 20 mL of venous blood was drawn from each subject. About 5 mL of this was put into sodium ethylenediaminetetraacetate (EDTA) specimen bottles for the full blood count parameters with Sysmex KX-21N hematology analyzer (made in Japan). The remaining 15 mL had serum separated for Sfr assay using enzyme-linked immunosorbent assay (ELISA) with a commercial assay kit manufactured by Teco Diagnostics. Results Significant difference was found in the mean Sfr concentration of subjects with MetS (163 ± 136.92 ng/mL) and regular donors (41.46 ± 40.33 ng/mL), P = 0.001. The mean Sfr concentrations of subjects with MetS (163 ± 136.92 ng/mL) were also higher than that of first-time donors (102.46 ± 80.26 ng/mL), but it was not statistically significant, P = 0.053. The Hb concentrations of the three groups were not significantly different. Conclusion Sfr concentrations of regular donors were lower than that of subjects with MetS and first-time donors. The difference between regular donors and subjects with MetS was statistically significant. However, there is no significant difference in the Hb concentrations in the three groups. MetS is not associated with anemia or hyperferritinemia