Functional Nano/Microcapsules: Synthesis And Characterization

Microencapsulation is a technique by which solid, liquid or gaseous active ingredients are enclosed within a shell material for the purpose of shielding the active ingredient from surrounding environment. The product therefrom is valuable as an active ingredient carrier and controlled release vehicle. In this research, polymer micro/nanocapsules with enclosed aqueous solution were synthesized through O/W emulsion-solvent evaporation technique. Specifically a commercial textile dye was encapsulated in poly (methyl methacrylate) (PMMA) micro/nanocapsules for an innovation of textile dyeing. A variety of synthesis parameters were studied including concentration of polymer, amount of dye, amount of surfactant, volume of surfactant aqueous solution, solvent evaporation temperature, and stirring speed. The obtained PMMA/dye capsules had average diameters from hundreds of nanometers to tens of micrometers with encapsulation efficiency ranging from 58% to 76%. FTIR and DSC results further confirmed the capsule structure of PMMA/dye. This work demonstrated a promising approach to enclose solution of active reagent in polymer micro/nanocapsules with good encapsulation efficiency

Individualism as Habitus: Reframing the Relationship between Income Inequality and Health

Public health literature has demonstrated a negative effect of income inequality on a number of health outcomes. Researchers have attempted to explain this phenomenon, drawing on psychosocial and neo-materialist explanations. This paper argues, however, that these approaches fail to recognize the crucial role of culture, focusing specifically on the cultural value of individualism. Through a review of the literature and Pierre Bourdieu’s theory of practice as a theoretical framework, I provide support for the proposition that an ideology based in individualism is the context within which income inequality, social fragmentation, material deprivation, and consequently poor health outcomes are produced. I further offer recommendations for continued research into the role of cultural determinants in the income inequality-health relationship

Toxicity, growth regulatory and repellent activities of medicinal plant extracts on Musca domestica L. (Diptera: Muscidea)

Housefly, Musca domestica, is a major vector for many medical and veterinary pathogenic organisms. The development of naturally occurring insecticides, represent one of the most promising approachesfor their ecochemical control. Petroleum-ether extracts of Griffonia simplicifolia and Zanthoxylum xanthoxyloides were assessed for their toxicity, growth regulatory and repellency to the housefly. Percent mortality and index of repellency induced by the extracts against the insects were found to be dose-dependent. Seed extracts of G. simplicifolia and root extracts of Z. xanthoxyloides were the mosteffective as toxicants and repellents against the fly. The LD50 in 24 h topical application of seed extracts of G. simplicifolia and root extracts of Z. xanthoxyloides were 0.28 and 0.35 ìg, respectively. Seed extracts of G. simplicifolia evoked a very strong regulatory effect against the second larval instar of the housefly. The RD50 of crude extracts of G. simplicifolia and Z. xanthoxyloides against housefly ranged from 1.0 to 6.8 and 1.3 to 1.7 ìg cm–2, respectively. Extracts of the two plant species may be useful as insecticides for controlling the housefly and should be exploited as a component of integrated vector control strategies or could be useful in the search of new larvicidal naturalcompounds

Farmers’ perceptions of benefits and risks from wastewater irrigation in Accra, Ghana

As safe water sources become scarcer and more polluted, the use of wastewater in urban agriculture may produce many benefits but may also lead to crop and soil contamination and endanger farmers and consumers. To effectively manage wastewater use in agriculture, it is important to understand how stakeholders feel impacted by the practice.

Susceptibility status of Anopheles gambiae s.l. (Diptera: Culicidae) from cabbage growing areas associated with pyrethroid and organophosphate use in Accra, Ghana

Resistance in malaria vectors is likely to be caused by the massive use of insecticides in agriculture. Anopheles gambiae s.l. collected from breeding grounds in two cabbage growing areas within Accra were assessed for levels of resistance to 0.75% permethrin, 0.05% deltamethrin, 5% malathion and 4% DDT using standard WHO susceptibility test kits. Pyrethroid and organophosphate residue levels in soil and run-off water from these cabbage farms were determined and possible association between resistance and residue levels were established. Compared to thesusceptible ‘Kisumu’ strain, both Korle-Bu and Airport populations were highly resistant to DDT and gave resistance levels which were over nine-fold for permethrin and over 2.5-fold for deltamethrin. Both wild and susceptible populations showed full susceptibility to malathion. The S and M forms of A. gambiae s.s. were found to occur in sympatry in the two study sites with a higher frequency of S form in the Airport area. Toxicity testing of extracts of soil and run-off water from these cabbage farms, using brine shrimp lethality tests, showed high level of toxicity, indicativeof the presence of residues of insecticides. Differential fractionation of these extracts using solid phase extractor (SPE) suggests that the bulk of residues in these extracts may be pyrethroids and organophosphates. No correlation was observed between either residue levels or residual bioactivity in soil and run-off water, and resistance levels in A.gambiae s.l. populations, collected from breeding grounds within the farms under investigation. It is proposed that resistance in A. gambiae larvae in these breeding sites contaminated with agricultural insecticides may have occurred over time due to continuous exposure to sub-lethal doses

Validity of measures for chronic disease in African settings

Epidemiological Change and Chronic Disease in Sub-Saharan Africa offers new and critical perspectives on the causes and consequences of recent epidemiological changes in sub-Saharan Africa, particularly on the increasing incidence of so-called ‘non-communicable’ and chronic conditions. Historians, social anthropologists, public health experts and social epidemiologists present important insights from a number of African perspectives and locations to present an incisive critique of ‘epidemiological transition’ theory and suggest alternative understandings of the epidemiological change on the continent. Arranged in three parts, ‘Temporalities: Beyond Transition’, ‘Numbers and Categories’ and ‘Local Biologies and Knowledge Systems’, the chapters cover a broad range of subjects and themes, including the trajectory of maternal mortality in East Africa, the African smoking epidemic, the history of sugar consumption in South Africa, causality between infectious and non-communicable diseases in Ghana and Belize, the complex relationships between adult hypertension and paediatric HIV in Botswana, and stories of cancer patients and their families as they pursue treatment and care in Kenya. In all, the volume provides insights drawn from historical perspectives and from the African social and clinical experience to offer new perspectives on the changing epidemiology of sub-Saharan Africa that go beyond theories of ‘transition’. It will be of value to students and researchers in Global Health, Medical Anthropology and Public Health, and to readers with an interest in African Studies

Urbanicity, Social Capital, and Depression in Older Adults: An Analysis of Two African Countries

Depression is a significant contributor to global morbidity and mortality and is the primary cause of disability worldwide. Older adults are an age group that may be more vulnerable to depression due to a higher prevalence of many known risk factors. Moreover, evidence also suggests that living in urban locations can increase the risk of depression and other mental illnesses. Thus, as the world’s population continues to age and urbanize, the burden of depression could increase. However, very few studies on the links between urbanicity and depression in older adults have been conducted in low- and middle-income settings such as sub-Saharan Africa, despite its rapid urbanization and substantial increases in the size of its aging population. Through quantitative analyses of secondary data from the Ghana and South Africa samples of the World Health Organization (WHO) Study on Global AGEing and Adult Health (SAGE), this dissertation therefore sought to explore the relationship between urbanicity and depression among older adults in an African context. The study specifically used multivariable logistic regression to examine the association between current urban residence and depression in Ghanaian and South African older adults as well as whether urbanicity of residence across the life course was associated with depression in these populations. It also assessed the influence of urbanicity on the relationship between depression and social capital—a purported protective factor—through structural equation modeling. Results indicated that there was no significant association between urbanicity and depression based on current residence or life-course residence in either country. Additionally, urbanicity did not substantially modify the effects of social capital on depression in either nation, but urban-rural differences in the level and composition of social capital were observed. Moreover, while trust was associated with a lower risk of depression in South Africa overall, sociability and trust were associated with an increased risk of depression in Ghana. These findings provide some insight into the socio-contextual determinants of depression in Ghanaian and South African older adults and may help to inform decisions on the allocation of mental health resources as well as policies and interventions to address later-life depression in these populations

Global inequalities: the impact on health

This chapter discusses concepts of inequality and inequity in relation to health both within and between nations. It explores inequalities in health by characteristics, such as social class, gender, ethnicity, and the intersection of these. The chapter discusses the importance of the social gradient of health. It addresses competing explanations for health and social inequalities globally, including poverty and material deprivation, psychosocial factors, discrimination, and structural determinants of health. The ‘social gradient in health’ expresses the idea that health status is often patterned and that each successive increment in social position confers additional advantage. The way in which inequalities are measured, and the ethical priorities adopted for health interventions may impact our understanding, of whether inequalities are improving or worsening with time. Acknowledging social causation as an explanation for health inequalities, several possible mechanisms have been explored to explain how social conditions affect health

Introduction

Epidemiological Change and Chronic Disease in Sub-Saharan Africa offers new and critical perspectives on the causes and consequences of recent epidemiological changes in sub-Saharan Africa, particularly on the increasing incidence of so-called ‘non-communicable’ and chronic conditions. Historians, social anthropologists, public health experts and social epidemiologists present important insights from a number of African perspectives and locations to present an incisive critique of ‘epidemiological transition’ theory and suggest alternative understandings of the epidemiological change on the continent. Arranged in three parts, ‘Temporalities: Beyond Transition’, ‘Numbers and Categories’ and ‘Local Biologies and Knowledge Systems’, the chapters cover a broad range of subjects and themes, including the trajectory of maternal mortality in East Africa, the African smoking epidemic, the history of sugar consumption in South Africa, causality between infectious and non-communicable diseases in Ghana and Belize, the complex relationships between adult hypertension and paediatric HIV in Botswana, and stories of cancer patients and their families as they pursue treatment and care in Kenya. In all, the volume provides insights drawn from historical perspectives and from the African social and clinical experience to offer new perspectives on the changing epidemiology of sub-Saharan Africa that go beyond theories of ‘transition’. It will be of value to students and researchers in Global Health, Medical Anthropology and Public Health, and to readers with an interest in African Studies