Determinants of maternal health care and birth outcome in the Dande Health and Demographic Surveillance System area, Angola

Objectives Maternal health care improvement and reduction of maternal and child mortality are priorities of the global health agenda. In Angola, maternal mortality remains high and the risk of pregnancy-related death was 1 in 32 during 2015. This study aims to identify demographic and social factors influencing antenatal care and health facility delivery among women in Dande and to understand their impact on birth outcomes. Methods This study is based on community–based longitudinal data collected by the Dande Health and Demographic Surveillance System between 2009 and 2015. Data on pregnancy outcomes (10,289 outcomes of 8,066 women) were collected for all reported pregnancies, including sociodemographic information, health services utilisation and women’s reproductive history. Logistic regression was used to investigate the determinants of birth outcomes, antenatal care attendance and institutionalised delivery. Findings Of the 10,289 pregnancy outcomes, 98.5% resulted in live births, 96.8% attended antenatal care, and 82.5% had four or more visits. Yet, 50.7% of the women delivered outside a health facility. Antenatal care attendance was a determinant of birth outcomes (stillbirth: unadjusted OR = 0.34 95% CI = 0.16–0.70; abortion: OR = 0.07 95% CI = 0.04–0.12). Older women, with lower education, living at a greater distance of a health facility and in rural areas, were less likely to use maternal health care. Having had previous pregnancies, namely resulting in live births, also decreased the likelihood of health care utilization by pregnant women. Conclusions The study identifies relevant social determinants for the utilisation of antenatal care, place of delivery and their impact on birth outcome, thereby providing insight on how best to address inequities in health care utilization.The core funding of all CISA activities has been provided by Camões - Portuguese Institute for Cooperation and Language, by the Calouste Gulbenkian Foundation, by the Angolan Ministry of Health and by the Bengo Province Government. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Fouling by aqueous suspensions of magnetite particles: the effect of pH and ionic strength

Particles adhesion Is one of the fundamental steps in heat exchanger fouling. Surface Interactions are affected by a con siderable number of factors related to the nature of the surfaces Involved. and to the composition and dynamics of the fouling fluid. Although quantitative predictions of U1e rate of adhesion are still not feasible !n practical situations. the evaluation of the potential energy of Interaction between two surfaces "in each vicinity" can be a valuable tool for the qualitative assessment of the fouling tendencies. For that purpose experimental determination of the parameters characterizing the physico-chemical properties of the Interacting surfaces are required. The present paper reports studies on particulate fouling caused by aqueous suspensions of magnetite on copper surfaces. A series of experiments were carried out at different pH values in the range of 7.5 - 9.5. For each pH two distinct types of experiments were performed: In one case the pH was controlled wlth NaOH and In the other the pH controlling medium was Na2co3. Each run lasted 20 days and at the end the thi ckness of the deposits was measured by means of a micrometer coupled to an electrical circuit. The zeta potentials and surface tensions of the solids were measured and used !n the Interpretation of the results. which was carried out In terms of the DLVO Theory

The use of hot wire techniques in fouling tests: a word of awareness

Hot metal wires have been used in fouling tests, mainly when corrosion or chemical reaction is present. Most authors who have reported data obtained with hot wire techniques make no refence about the phenomenon related to the increase In surface area due to the accumulation of fouling layers. Yet this can cause problems of reverse insulation (critical radius), affecting the conclusions taken directly from the readouts. The aim of this paper is to discuss this problem and show through a few selected tases the Importance of this aspect in fouling resistance determinations using hot wire techniques

Efeitos de superfície na deposição de partículas de magnetite e de caulino sobre superfícies de cobre

A deposição de partículas em meta aquoso é regida pela ação combinada de diferentes interações superficiais e forças hidrodinâmicas. De entre o elevado número de factores que podem afectar as interações superficiais seleccionaram-se para estudo o efeito do pH e da força iónica do meio. Realizaram-se ensaios de deposição, sobre superfícies de cobre, com suspensões aquosas de magnetite e de caulino para valores de pH compreendidos entre 7 e 11. Para cada valor de pH foram feitos dois tipos distintos de ensaios: num caso o controlo do meio foi feito com NaOH, no outro com Na2CO3. Efectuaram-se ainda, outros ensaios em que, para um dado valor do pH, se alterou a força iónica do meio por adição de sais neutros (NaNO3 e NaC1). Para auxiliar a interpretação dos resultados obtidos nos ensaios anteriormente referidos, determinaram-se os potenciais zeta das partículas e do cobre em função do pH e calcularam-se as energias livres de adesão partícula-liquido-superfície. Os resultados obtidos têm sido analisados com base na teoria DLVO, com vista à compreensão dos mecanismos que lhe estão subjacentes. Embora não fosse previsível, pelo menos no caso do caulino, a melhor justificação para os resultados obtidos é conseguida admitindo que a interação entre as duplas camadas eléctricas de partículas e superfície se processa a potencial constante

Fouling by aqueous suspensions of kaolin and magnetite

Experimental studies on particulate fouling were carried out in annular cross sections using aqueous kaolin and kaolin- magnetite suspensions . Tests with kaolin-water suspensions showed that the pH and the ions in solution have a significant effect on the 8.DX)UDt of deposit . Increasing the pH above I , the 8.DX)unt of deposit tends to decrease . However the extent to which the thickness decreases is very much dependent on the chemical substances used to control the pH . The presence of magnetite in kaolin suspensions at pH= 1 .5 reduced the amount of deposit , although increasing its mechanical strength. This seems to be due to the magnitude of the adhesion forces between the particles, which is greater in the presence of iron oxide

Dislocated negative feedback control with partial replacement between chaotic Lorenz systems

In order to obtain asymptotical synchronization, we combine negative feedback control and dislocated negative feedback control with partial replacement to the nonlinear terms of the response system, a coupling version that was less explored. All these unidirectional coupling schemes are applied between Lorenz systems where we consider some values for the control parameters that lead to chaotic behavior. The sufficient conditions for global stable synchronization are obtained from a different approach of the Lyapunov direct method for the transversal system. In one of the coupling we apply a result based on the classification of the symmetric matrix AT +A as negative definite,where A is characterizing the transversal system. In the other couplings presented here, the sufficient conditions are based on the derivative increase of an appropriate Lyapunov function. In fact, the effectiveness of the coupling between systems with equal dimension follows from the analysis of the synchronization error, e(t), and, if the system variables can be bounded by positive constants, then the derivative of an appropriate Lyapunov function can be increased as required by the Lyapunov direct method

Real-time quantitative PCR with SYBR Green I detection for estimating copy numbers of nine drug resistance candidate genes in Plasmodium falciparum

BACKGROUND: Evaluating copy numbers of given genes in Plasmodium falciparum parasites is of major importance for laboratory-based studies or epidemiological surveys. For instance, pfmdr1 gene amplification has been associated with resistance to quinine derivatives and several genes involved in anti-oxidant defence may play an important role in resistance to antimalarial drugs, although their potential involvement has been overlooked. METHODS: The (ΔΔ)Ct method of relative quantification using real-time quantitative PCR with SYBR Green I detection was adapted and optimized to estimate copy numbers of three genes previously indicated as putative candidates of resistance to quinolines and artemisinin derivatives: pfmdr1, pfatp6 (SERCA) and pftctp, and in six further genes involved in oxidative stress responses. RESULTS: Using carefully designed specific RT-qPCR oligonucleotides, the methods were optimized for each gene and validated by the accurate measure of previously known number of copies of the pfmdr1 gene in the laboratory reference strains P. falciparum 3D7 and Dd2. Subsequently, Standard Operating Procedures (SOPs) were developed to the remaining genes under study and successfully applied to DNA obtained from dried filter blood spots of field isolates of P. falciparum collected in São Tomé & Principe, West Africa. CONCLUSION: The SOPs reported here may be used as a high throughput tool to investigate the role of these drug resistance gene candidates in laboratory studies or large scale epidemiological surveys

Candida glabrata and Candida albicans single and co-colonization of acrylic in presence of saliva

Oral candidosis is a frequent problem in immunocompromised patients and Candida albicans is regarded as the leading cause of such infections. However, recently, Candida glabrata has emerged as an important pathogen, occurring both singly or in mixed species infections, often with C. albicans. Compared with C. albicans, few is known about the role of C. glabrata in oral infection. Furthermore the use of denture acrylic surfaces is a prerequisite for adhesion and biofilm formation by Candida species in oral environment. Thus, the aim of this study was to examine the adhesion and biofilm formation ability by single and mixed C. glabrata and C. albicans species on acrylic in the presence of artificial saliva. Adhesion ability was quantified by colony forming units (CFUs) counting using CHROMagar medium and the total biomass quantified by crystal violet. Epifluorescence and confocal microscopy observations were used for examining the biofilm structure using species specific peptide nucleic acid (PNA) probe hybridisation. The results showed that C. glabrata had higher ability to adhere and form biofilms on acrylic comparatively to C. albicans. Additionally, co-culture studies showed that the presence of C. albicans did not affect the ability of C. glabrata to adhere to acrylic surface. Microscopy images are in accordance with CFUs and crystal violet staining results. The importance of recognising the occurrence of infections associated to mixed biofilms is highlighted by the results of this study and represents an area that should be considered by both diagnostic laboratories and clinicians