Localization Based on Parallel Robots Kinematics as an Alternative to Trilateration

In this work a new scheme for range-based localization is proposed. The main goal is to estimate the position of a mobile point based on distance measurements from fixed devices, called anchors, and on inertial measurements. Due to the non-linear nature of the problem, an analytic relation to compute the position starting from these measurements does not exist, and often trilateration methods are used, generally based on least-square algorithms. The proposed scheme is based on the modelling of the localization process as a parallel robot, thereby methodologies and control algorithms used in the robotic area can be exploited. In particular, a closed loop control system is designed for tracking the position of a mobile point based on range measurements from fixed anchors, and it is shown a peculiar structure of the tracking error dynamics, whose allows an intuitive gain tuning and ensures global exponential stability. Moreover, it is also shown a nice connection between tuning parameters and rate of convergence of the estimation error. Experimental results confirm the validity of the proposed localization method

Trajectory robust control of autonomous quadcopters based on model decoupling and disturbance estimation

In this article, a systematic procedure is given for determining a robust motion control law for autonomous quadcopters, starting from an input–output linearizable model. In particular, the suggested technique can be considered as a robust feedback linearization (FL), where the nonlinear state-feedback terms, which contain the aerodynamic forces and moments and other unknown disturbances, are estimated online by means of extended state observers. Therefore, the control system is made robust against unmodelled dynamics and endogenous as well as exogenous disturbances. The desired closed-loop dynamics is obtained by means of pole assignment. To have a feasible control action, that is, the forces produced by the motors belong to an admissible set of forces, suitable reference signals are generated by means of differentiators supplied by the desired trajectory. The proposed control algorithm is tested by means of simulation experiments on a Raspberry-PI board by means of the hardware-in-the-loop method, showing the effectiveness of the proposed approach. Moreover, it is compared with the standard FL control method, where the above nonlinear terms are computed using nominal parameters and the aerodynamical disturbances are neglected. The comparison shows that the control algorithm based on the online estimation of the above nonlinear state-feedback terms gives better static and dynamic behaviour over the standard FL control method

Gender Analysis of Students Performances in Matching and Completion Test Formats; A Chemistry Achievement Test

This study compared the difficulty and discriminatory indices of boys and girls in matching and completion test format of chemistry achievement test. The research design was a descriptive   survey   type, the sample consisted of four hundred (400) SS 111 Students randomly selected from eight (8) public Senior Secondary Schools in A do Local Government Area of Ekiti State, The instrument was made up of two parallel objective test format on Chemistry Review Questionnaire (matching and completion formats).The first is a 60-item matching test which is essentially a replica of the sixty 60-item completion test. Both tests were strictly based on the same content. The two instruments were administered simultaneously. Data collected were analysed for P-values and d-values using correlation analysis, t-test and z-test. Two hypotheses were generated and tested at 0.05 level of significance. The result of the analysis showed that there is significant difference between the performance of male and female students in the completion test format of chemistry test; there is significant difference between the performance of male and female students in the matching test format of chemistry achievement test. It was therefore asserted that completion test and matching test can be used as complementary test item with the other forms of test in use presently. Keywords: Matching Tests, Difficulty Index, Difficulty Level, Discriminating Index, Completion Items, Item

Sliding Mode Control of Quadratic Boost Converters Based on Min-Type Control Strategy

The paper deals with the control of a quadratic boost converter supplied by low-voltage energy sources, such as photovoltaic panels, fuel cells, or batteries. The control scheme consists of two control loops. A min-type controller governs the inner loop to force the current state of the nominal model to converge in a neighborhood of the equilibrium state. The external loop processes the output tracking error using an integrator, and it allows reconfiguring the converter's working point by changing the equilibrium state given in the input to the internal loop. This configuration assures both zero tracking error of the output voltage and robustness against load and input voltage variations and converter parameter uncertainties. The stability of the whole system is investigated using the hybrid system framework. The proposed control technique has been tested experimentally in a suitably developed (low-cost) setup, and the results show the effectiveness of the proposed approach

Ethnic Conflict and Sustainable Development in Nigeria: The Role of Peace Education

The issue of ethnic conflict in Nigeria has become a burning national issue with its attendant problems. Its current predominance is reflected in the reports of various activities of ethnic militant in the country coupled with the high rising terrorism activities in the northern part of the country from which the traces of ethnicity problem cannot be totally ruled out. However, the issue now nationwide is no longer the recognition of ethnic conflict and its increasing threats to lives and properties but on how to curtail and manage it so that both human and material resources being used for such activities can be geared towards bringing about sustainable development in all spheres of life. The problem could best be tackled through deliberate and sincere efforts to change the behaviour and attitudes of the people to become their brothers’ keeper and tolerate one another. This could best be achieved upon the teaching of peace education in the schools. Therefore, this paper discusses ethnic conflict, reviews its trends and management and finally highlights the strategy for ethnic conflictresolution and management in Nigeria

Demographic attributes of COVID-19 patients in an Infectious Disease Center of Nigeria

Background: As part of our contribution to the growing pool of knowledge on the prevention and control of the COVID-19 pandemic, this study describes the demographic features of patients with COVID-19 hospitalized at Infectious Disease Center (IDC), Olodo, Ibadan, Oyo State, Nigeria.Methodology: This was a descriptive cross-sectional study of COVID-19 patients whose data were collected during admission between April 27, 2020 and June 20, 2020. SARS-CoV-2 infection was diagnosed on nasopharyngeal specimen using a real-time reverse transcription–polymerase chain reaction (rRT-PCR) assay. Data were analysed using the Statistical Package for Social Sciences (SPSS Inc., USA) version 20.0Results: Among 131 patients, 58% were between age 18 and 35 years, 48.1% were employees of private establishments, and 64.1% were males. High proportion (84.3%) of the patients spent less than 14 days on admission. As at June 20, 2020, the overall COVID-19 mortality in the IDC was 0.0%.Conclusion: This study concluded that COVID-19 was common among male Nigerians, those working in private establishments, and those aged 18-35 years. Future researches on COVID-19 in Nigeria must put gender and age into consideration. Keywords: SARS-COV2; COVID-19; age; gender; occupation French Title: Attributs démographiques des patients atteints de COVID-19dans un centre de maladies infectieuses du Nigéria Contexte: Dans le cadre de notre contribution au pool croissant de connaissances sur la prévention et le contrôle de la pandémie COVID-19, cette étude décrit les caractéristiques démographiques des patients atteints de COVID19 hospitalisés au Centre des maladies infectieuses (IDC), Olodo, Ibadan, État d'Oyo, Nigéria. Méthodologie: Il s'agissait d'une étude transversale descriptive de patients atteints de COVID-19 dont lesdonnées ont été collectées lors de l'admission entre le 27 avril 2020 et le 20 juin 2020. L'infection par le  SRASCoV-2 a été diagnostiquée sur un échantillon nasopharyngé à l'aide d'une transcription inverse en temps réel–Test de réaction en chaîne par polymérase (rRT-PCR). Les données ont été analysées à l'aide du StatisticalPackage for Social Sciences (SPSS Inc., USA) version 20.0 Résultats: Parmi 131 patients, 58% avaient entre 18 et 35 ans, 48,1% étaient des employés d'établissementsprivés et 64,1% étaient des hommes. Une forte proportion (84,3%) des patients ont passé moins de 14 jours àl'admission. Au 20 juin 2020, la mortalité globale par COVID-19 dans l'IDC était de 0,0%. Conclusion: Cette étude a conclu que le COVID-19 était courant chez les hommes Nigérians, ceux travaillantdans des établissements privés et ceux âgés de 18 à 35 ans. Les futures recherches sur le COVID-19 au Nigériadoivent prendre en compte le sexe et l'âge. Mots clés: SRAS-COV2; COVID-19; âge; le sexe; occupatio

Cost-effectiveness analysis of a large-scale crèche intervention to prevent child drowning in rural Bangladesh

Background Drowning is the leading cause of death among children 12–59 months old in rural Bangladesh. This study evaluated the cost-effectiveness of a large-scale crèche (daycare) intervention in preventing child drowning. Methods The cost of the crèches intervention was evaluated using an ingredients-based approach and monthly expenditure data collected prospectively throughout the study period from two agencies implementing the intervention in different study areas. The estimate of the effectiveness of the crèches intervention was based on a previous study. The study evaluated the cost-effectiveness from both a program and societal perspective. Results From the program perspective the annual operating cost of a crèche was $416.35 (95$221 to $576), the annual cost per child was$16 (95% CI: $8 to$23), and the incremental-cost-effectiveness ratio (ICER) per life saved with the crèches was $17,008 (95$8817 to $24,619). From the societal perspective (including parents time valued) the ICER per life saved was −$166,833 (95% CI: − $197,421 to −$141,341)—meaning crèches generated net economic benefits per child enrolled. Based on the ICER per disability-adjusted-life years averted from the societal perspective (excluding parents time), $1978, the crèche intervention was cost-effective even when the societal economic benefits were ignored. Conclusions Based on the evidence, the crèche intervention has great potential for generating net societal economic gains by reducing child drowning at a program cost that is reasonable

Transcriptomic analysis links diverse hypothalamic cell types to fibroblast growth factor 1-induced sustained diabetes remission

n rodent models of type 2 diabetes (T2D), sustained remission of hyperglycemia can be induced by a single intracerebroventricular (icv) injection of fibroblast growth factor 1 (FGF1), and the mediobasal hypothalamus (MBH) was recently implicated as the brain area responsible for this effect. To better understand the cellular response to FGF1 in the MBH, we sequenced >79,000 single-cell transcriptomes from the hypothalamus of diabetic Lepob/ob mice obtained on Days 1 and 5 after icv injection of either FGF1 or vehicle. A wide range of transcriptional responses to FGF1 was observed across diverse hypothalamic cell types, with glial cell types responding much more robustly than neurons at both time points. Tanycytes and ependymal cells were the most FGF1-responsive cell type at Day 1, but astrocytes and oligodendrocyte lineage cells subsequently became more responsive. Based on histochemical and ultrastructural evidence of enhanced cell-cell interactions between astrocytes and Agrp neurons (key components of the melanocortin system), we performed a series of studies showing that intact melanocortin signaling is required for the sustained antidiabetic action of FGF1. These data collectively suggest that hypothalamic glial cells are leading targets for the effects of FGF1 and that sustained diabetes remission is dependent on intact melanocortin signaling

Evolutionary History of Rabies in Ghana

Rabies virus (RABV) is enzootic throughout Africa, with the domestic dog (Canis familiaris) being the principal vector. Dog rabies is estimated to cause 24,000 human deaths per year in Africa, however, this estimate is still considered to be conservative. Two sub-Saharan African RABV lineages have been detected in West Africa. Lineage 2 is present throughout West Africa, whereas Africa 1a dominates in northern and eastern Africa, but has been detected in Nigeria and Gabon, and Africa 1b was previously absent from West Africa. We confirmed the presence of RABV in a cohort of 76 brain samples obtained from rabid animals in Ghana collected over an eighteen-month period (2007–2009). Phylogenetic analysis of the sequences obtained confirmed all viruses to be RABV, belonging to lineages previously detected in sub-Saharan Africa. However, unlike earlier reported studies that suggested a single lineage (Africa 2) circulates in West Africa, we identified viruses belonging to the Africa 2 lineage and both Africa 1 (a and b) sub-lineages. Phylogeographic Bayesian Markov chain Monte Carlo analysis of a 405 bp fragment of the RABV nucleoprotein gene from the 76 new sequences derived from Ghanaian animals suggest that within the Africa 2 lineage three clades co-circulate with their origins in other West African countries. Africa 1a is probably a western extension of a clade circulating in central Africa and the Africa 1b virus a probable recent introduction from eastern Africa. We also developed and tested a novel reverse-transcription loop-mediated isothermal amplification (RT-LAMP) assay for the detection of RABV in African laboratories. This RT-LAMP was shown to detect both Africa 1 and 2 viruses, including its adaptation to a lateral flow device format for product visualization. These data suggest that RABV epidemiology is more complex than previously thought in West Africa and that there have been repeated introductions of RABV into Ghana. This analysis highlights the potential problems of individual developing nations implementing rabies control programmes in the absence of a regional programme

An equity analysis of utilization of health services in Afghanistan using a national household survey

Abstract Background Afghanistan has made great strides in the coverage of health services across the country but coverage of key indicators remains low nationally and whether the poorest households are accessing these services is not well understood. Methods We analyzed the Afghanistan Mortality Survey 2010 on utilization of inpatient and outpatient care, institutional delivery and antenatal care by wealth quintiles. Concentration indexes (CIs) were generated to measure the inequality of using the four services. Additional analyses were conducted to examine factors that explain the health inequalities (e.g. age, gender, education and residence). Results Among households reporting utilization of health services, public health facilities were used more often for inpatient care, while they were used less for outpatient care. Overall, the utilization of inpatient and outpatient care, and antenatal care was equally distributed among income groups, with CIs of 0.04, 0.03 and 0.08, respectively. However, the poor used more public facilities while the wealthy used more private facilities. There was a substantial inequality in the use of institutional delivery services, with a CI of 0.31. Poorer women had a lower rate of institutional deliveries overall, in both public and private facilities, compared to the wealthy. Location was an important factor in explaining the inequality in the use of health services. Conclusions The large gap between the rich and poor in access to and utilization of key maternal services, such as institutional delivery, may be a central factor to the high rates of maternal mortality and morbidity and impedes efforts to make progress toward universal health coverage. While poorer households use public health services more often, the use of public facilities for outpatient visits remains half that of private facilities. Pro-poor targeting as well as a better understanding of the private sector’s role in increasing equitable coverage of maternal health services is needed. Equity-oriented approaches in health should be prioritized to promote more inclusive health system reforms