Switched step integral backstepping control for nonlinear motion systems with application to a laboratory helicopter

In this paper, the energy efficiency of the widespread application of backstepping control to a class of nonlinear motion systems is investigated. A Switched Step Integral Backstepping Control (SSIBC) scheme is introduced to improve immunity to measurement noise and to increase the energy efficiency of conventional backstepping in practice. The SSIBC is realized by switching between two candidate controllers obtained at different steps of the iterative backstepping design process. A bi-state dependent hysteresis rule is developed to supervise stable switching between the different regimes in the presence of noise. The proposed method is experimentally verified on a MIMO twin rotor laboratory helicopter involving coupled nonlinear dynamics, inaccessible states and uncertainties. Experimental results show that in addition to a reduction in power consumption, the SSIBC reduces saturation of the control signal and visible motor jerking in contrast with conventional backstepping. Additional comparisons with a previously proposed optimized decoupling PID controller also show significant improvement in precision achieved with higher energy efficiency. Experimental results obtained with the introduction of an external disturbance into the system also show the robustness of the proposed SSIBC.

Individual and ecological analyses of antenatal care: Prospects for delivery assistance and use of modern family planning in Nigeria

Despite the availability of healthcare centres for the provision of antenatal care (ANC) services in Nigeria, the services are still underutilized by pregnant women. ANC services not only reduce maternal mortality and birth defects, but also have a strong link to many causes of maternal deaths. This study explored the individual and ecological relationships between antenatal care, skilled birth assistance during delivery, and family planning use across states in Nigeria. This study was a secondary analysis of data from the 2018 National Nutrition and Health Survey (NNHS) carried out among 24,985 women aged 15-49 years in the 36 states and the Federal Capital Territory (FCT) in Nigeria. Analysis was carried out at the level of individual women and at the ecological level. Only 68.3% visited a health professional (doctors, nurses, midwives, community health extension workers, and community health officers) for ANC in the most recent pregnancy before the survey. At delivery, 44.9% were assisted by delivery attendants with about half (50.1%) assisted by non-professional (traditional birth attendants, relatives and friends) during delivery. There was a significant variation in use of modern family planning (FP) across types of ANC provider. There was a strong positive correlation between ANC utilisation and skilled birth attendance (SBA) (r=0.706, p <0.001), and between SBA and FP (r=0.730, p <0.001). These results have implications for the design of appropriate interventions for strengthening the role of healthcare providers to enhance ANC patronage, utilization of safe delivery services and sustained use of reproductive health services.

Missed opportunities for HIV counselling and testing service delivery among pregnant women in Nigeria: Evidence from the 2018 National nutrition and health survey

According to UNAIDS, the 90-90-90 strategy calls for 90% of HIV-infected individuals to be diagnosed by 2020, 90% of whom will be on anti-retroviral therapy (ART) and 90% of whom will achieve sustained virologic suppression. HIV counselling and testing (HCT) is an important entry point for effective prevention of mother-to-child transmission of HIV. However, evidence abounds that HCT is often missed by pregnant women during antenatal care in Nigeria. We used secondary data from the 2018 Nigerian National Nutrition and Health Survey (NNHS) to determine the pattern of missed opportunities within the HCT algorithm and the factors associated with the missed opportunities. Of the 8,329 eligible women, 2,327 (27.9%) missed HCT because of lack of antenatal care; 1,493 (24.9%) missed HIV pre-test counselling; 180 (4.0%) missed HIV testing after participating in pre-test counselling, while 793 (18.2%) missed collection of HIV result and post-test counselling. Generally, most of the women that missed HCT were from the North West (43.3%) and had their antenatal care with traditional birth attendants. The odds of missing ANC were higher in women in the Northern and Southern regions. Concerning pre-test HIV counselling, the odds of missing it were higher among women in the Northwest and Southeast while the odds of missing post-test counselling of HIV test were higher among women in the Northeast and Southeast relative to other regions. Using TBA as a care provider was associated with higher odds of women missing pre-test and post-test counselling of HIV during ANC compared to those that used doctors or midwives or CHEWs. Missed opportunities are common in different stages of HIV counselling and testing pathway in Nigeria, particularly in the Northern regions. Future studies would need to identify the specific reasons for these missed opportunities, enabling the targeting of more specific policy reform and interventions.

Prevalence and predictive factors for early initiation of breastfeeding in Nigeria: Evidence from the Nigerian demographic and health survey (2003-2018)

Early initiation of breastfeeding (EIBF) is an essential first step in exclusive breastfeeding that is expected to commence within an hour after childbirth. This study examined the prevalence and the factors associated with EIBF among nursing mothers in Nigeria based on an analysis of the 2003, 2008, 2013, and 2018 Nigerian Demographic Health Survey (NDHS) data. The prevalence of early breastfeeding initiation by women's demographic, socio-economic and reproductive characteristics were computed for each of the survey rounds. The differences in the prevalence estimates for early breastfeeding initiation between the last two survey periods were calculated. A crude and adjusted model to examine association between explanatory variables and early breastfeeding initiation were fitted using Poisson regression model. The mean age of respondents was 29 years (SD=7.3). The prevalence of EIBF increased from 31.5% in 2003 (95% CI 28.4-34.5) to 43.8% in 2018 (95% CI 42.6-45.0), with a decline to 35.3% in 2013 (95% CI 34.0-36.7). The identified risk factors associated with EIBF were being 35-39 years, having at least a primary education, lower wealth quintiles, multiparity, and delivery in a public hospital. EIBF was lower among women that had skilled occupation, access to media, decided to delay pregnancy, history of previous caesarean section, small size baby at birth, and women who received antenatal care. The results indicate that the proportion of women with EIBF in Nigeria is low. Addressing the barriers identified in this paper will help promote EIBF practices in the country.

Assessment of diagnostic accuracy and adherence to maternal and child health guidelines as a measure of clinical competence of frontline healthcare workers in Nigeria

Clinical competence of primary healthcare (PHC) workers is important in the delivery of maternal and child health care and services. In this cross-sectional study, we investigated the diagnostic accuracy and adherence to clinical guidelines for the management of some clinical conditions such as malaria, diarrhea, pneumonia, neonatal asphyxia and postpartum hemorrhage, as a proxy to measure the clinical competence of frontline health workers in PHCs in selected states in Nigeria. Ninety PHC facilities were randomly selected in each State and the FCT. Of the 3330 health workers, only 36.0% were able to correctly diagnose the five selected medical conditions. There was a significant difference in the diagnostic accuracy of the health workers with the doctors having highest diagnostic accuracy (65.5%) compared to other health workers (p <0.001). Adherence to the management guidelines was generally poor across all cadres of health workers and this pattern appear similar across the geopolitical regions in the country. The highest adherence to guidelines was observed among medical doctors (38.2%). The diagnostic accuracy and adherence to national guidelines for managing patients was poor among health workers, particularly, among other cadres except doctors. PHC workers in Nigeria need continuous training to enhance their clinical competence to improve quality of maternal and child health care.

Uptake of modern and traditional contraceptive methods in Nigeria: Lessons from a nationwide initiative on programming for results (2015-2018)

In general, family planning uptake promotes healthy living among couples and their children, in addition to aiding national development. This study was a secondary analysis of data collected from two nationally representative data - 2015 and 2018 National Nutrition and Health Surveys (NNHS) - aimed at measuring the uptake of modern and traditional contraceptive methods among women of reproductive age in Nigeria. The data were analysed by presenting differentials in prevalence of modern and traditional contraceptives between 2015 and 2018. The results showed that during the periods modern contraceptive uptake in Nigeria ranged between 10% and 17%. By contrast, the prevalence of the traditional methods was 8.3% and 10.0%. Within four years (2015-2018), the average national modern contraceptive uptake among women increased by 7%, while the traditional contraceptive uptake reduced by 2%. The uptake of both modern and traditional contraceptive methods varied by ages group of women, geo-political regions, and State of residence. We conclude that the uptake of modern contraception is below expectation in all regions in Nigeria. The uptake is worse in the northern regions as compared to the southern regions. Government needs to invest more to increase access to and utilization of modern contraceptive methods.

Prevalence and patterns of anthropometric failure among under-five children in Nigeria: Evidence from the National nutrition and health survey, 2018

Globally, malnutrition among under-five children remains a public health concern. There is increasing concern at research and policy levels about anthropometric failure and the double burden of child malnutrition across different groups of children. The objective of this study was to describe the magnitude and distribution of various forms of anthropometric failure (AF) among children under age five in Nigeria. We used the 2018 National Nutrition and Health Survey data collected among 19,471 under-five children in Nigeria. The most prevalent AF was stunting only (17.7%) followed by stunting and underweight (13.9%). Wasting, stunting and underweight was found among 3.5% of the sample. Wasting, stunting and underweight was most common in age 6-11 months (7.0%) and 12-23 months (6.9%). Overall, about 1 out of 5 under-five children has multiple anthropometric failure. The peak age group for multiple AFs was between six months and 35 months. Multiple AF was less likely among females compared to males (RR=0.74, CI: 0.69, 0.80). The risk of multiple AF was higher in both North East (RR=2.15, CI: 1.78, 2.59) and North West (RR=2.98, CI: 2.51, 3.55) relative to the North Central. In contrast, the risk was lesser in the South East (RR=0.75, CI: 0.59, 0.95) and other southern regions. The study showed that multiple anthropometric failure is a common problem among children in Nigeria. Programmes that will support prevention and early identification of different types of malnutrition among under-five children across States in Nigeria are recommended.

Knowledge of health effects and determinants of psychoactive substance use among secondary school students in Sokoto Metropolis, Nigeria

Introduction

psychoactive substance use (PSU) is a patterned use of a drug in which the user consumes the substance in amounts or methods which are harmful to themselves or others. Psychoactive substance use takes a considerable toll on financial status, academic achievement and health status of addicts. In Nigeria, PSU is on the increase, one of the most disturbing health-related problems and a leading cause of premature death among school aged population worldwide. We therefore, determined the knowledge of health effects and determinants of psychoactive substance use among secondary school students in Sokoto Metropolis, Nigeria.

Methods

we conducted a cross-sectional study among 430 secondary school students that were selected using multistage sampling in Sokoto, Northwestern, Nigeria from April to May 2019. We collected data using a semi-structured, interviewer-administered questionnaire. We calculated proportions and adjusted odds ratios (OR) with 95% confidence intervals (CI) in a binary logistic regression model.

Results

knowledge of health effects of PSU was good in 38.1% of the respondents with a mean score of 19.6 ± 10.0. The overall prevalence of PSU was high among current users (16.3%), male participants (78.6%) and those aged 17-years or more (68.6%). Independent predictors of current use of psychoactive substances were poor knowledge of health effects (aOR: 4.1, 95% CI: 1.7-10.0) and father´s use of psychoactive substances (aOR: 10.3, 95% CI= 1.9-57.1).

Conclusion

knowledge of health effects of psychoactive substances was generally poor among the participants with an associated high prevalence among current users. Poor knowledge of its health effects determines the use of psychoactive substances. We conducted awareness campaigns and health talk on health effects of PSU to secondary school students in the State. The Federal Ministry of Education should ensure that PSU-related topics are incorporated in the secondary school curriculum.