121 research outputs found

    Impacts of Climate Change on Maize and Beans Production and Compatibility of Adaptation Strategies in Pangani River Basin, Tanzania

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    Climate change present new development challenges particularly in Sub-Saharan countries where the majority of the population depend on climate-sensitive activities such as rain-fed agriculture. This necessitates for a need to focus on impacts of climate change and compatibility of adaptation as a way of providing sustainable solutions to reduce the vulnerability of the majority of poor Sub-Saharan communities. This study employed Ricardian approach to assess the impacts of temperature and rainfall variability on the net revenue from two main food crops (maize and beans) from Pangani River Basin produced primarily under rain fed agriculture. The study also employed the gross margin to assess the compatibility of irrigation adaptation strategy. The results indicate that increase in temperature and decrease in rainfall has decreased the net revenue from maize and beans production and raised rent for irrigated farms particularly in the middle and low altitudes of the basin. Increase in temperature has increased the net revenue from maize and beans production in the upper altitudes of basin. The results clearly demonstrate that climate change have affected the livelihood of the majority of the poor small scale farmers found in the middle and lower altitudes and improved that of farmers living in the upper. They also demonstrate that irrigation is a significant technique for adaptation to climate change in the basin

    Does Household Capital Mediate the Uptake of Agricultural Land, Crop, and Livestock Adaptations? Evidence From the Indo-Gangetic Plains (India)

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    Farmers in the Indo-Gangetic Plains produce much of the wheat and rice grown in India. However, food production and millions of farm-based livelihoods in this region will continue to be adversely affected by hydro-climatic change and variation, reduced land productivity, and declining groundwater levels. Thus, agricultural adaptations are essential for protecting and improving upon intersecting goals of food security, poverty alleviation, and wellbeing. Household “capital” (e.g., natural, human, financial, physical, and social) is commonly cited as an indicator of livelihood adaptability and innovation. We develop a series of mediated structural equation models to empirically evaluate the validity of capital as a suitable indicator for adaptation and adaptive capacity. These models assess the extent to which household capital mediates the relationship between over 1,000 socio-economically differentiated and randomly selected farm households, and their crop, livestock, and land management adaptations in the states of Haryana and Bihar. Central to our models is a single household capital variable, constructed by aggregating nearly 80 different measurements of households\u27 (i) physical/infrastructural capital, (ii) owned or accessed assets, (iii) livelihood diversity, (iv) ability to reach market or commercialize, (v) access to weather information, and (vi) social capital. We find household capital is a significant predictor in adopting crop, land management, and livestock-related adaptation strategies across both states. Second, and in certain cases, lower castes and less educated households engaged in fewer agricultural adaptations—an outcome mediated by their lower composition of capital. Further, and across almost all contexts, household capital mediated the effect of owning a greater proportion of land, and the higher uptake of agricultural adaptation activities. While improvements in any capital category can improve adoption, we recommend programs that improve (i) access to public and private agricultural infrastructure for lower castes; (ii) education and shared knowledge spaces for less-educated households; and (iii) the availability of low-interest loans and the more efficient legal transfer of land for agriculturalists owning a smaller proportion of their land. Through this novel and large-scale analysis of household data, we provide short-term and immediate recommendations for more equitable agricultural adaptation in this breadbasket region of northern India

    Silicosis and silicotuberculosis among respiratory hospital admissions: A cross-sectional survey in northern Tanzania

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    Background. There is little evidence describing respiratory disease among 40.5 million small-scale miners worldwide. Objectives. To describe the prevalence and clinical characteristics of adult respiratory inpatients with silicosis and silicotuberculosis in a tertiary hospital in Tanzania that serves a small-scale mining region. Methods. In this retrospective, cross-sectional survey, patient files from admissions between 2010 and 2020 were opportunistically selected and included if a respiratory diagnosis had been made. Results. Of 223 patients with respiratory conditions, 32 (14.3%; 95% confidence interval (CI) 10.0 - 19.6) were diagnosed with silicosis and 17 (7.6%; 95% CI 4.5 - 11.9) with silicotuberculosis. Mining was the most frequent occupation in those with silicosis (n=15/32; 46.9%) and silicotuberculosis (n=15/17; 88.2%). Of those with silicosis or silicotuberculosis, 26/49 (53.1%) were aged <45 years. Conclusion. Our study suggests that silicosis and silicotuberculosis are common among male and female respiratory inpatients with occupational exposure. The study highlights the role of occupational exposures in respiratory disease in developing economies

    Exploring Electronic Waste Situation in Africa: A review

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    In recent years African countries are grappling with the increase of electronic waste (e-waste) which poses challenge to environment and human health. However, factors influencing electronic waste situation in Africa have not been explored and thus not well understood. To fill the gap, this paper aims at exploring e-waste situation in Africa and analysing factors influencing the situation.  To address the objective, a systematic literature review was adopted. Findings show that the amount of e-waste has been increasing in both developed and developing countries over time. Although there are common factors associated with the increase of e-waste, some factors are unique to Africa. These are: reduced cost of used items, taxi incentives for importation of electronic devices and increased use of ICT devices in various sectors.  Furthermore, findings show that developed and developing countries differ in terms of the risks posed by the e-waste and this difference is dependent on how e-waste is managed. Based on the findings, it can be concluded that the situation of e-waste in Africa is somehow different from developed world both in terms of the factors influencing the situation and ways of managing e-waste. In order to deal with e-waste situation, African countries need to improve awareness of their people, establish and capacitate institutions for dealing with e-waste and invest in technologies for managing e-waste

    A new ghost cell/level set method for moving boundary problems:application to tumor growth

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    In this paper, we present a ghost cell/level set method for the evolution of interfaces whose normal velocity depend upon the solutions of linear and nonlinear quasi-steady reaction-diffusion equations with curvature-dependent boundary conditions. Our technique includes a ghost cell method that accurately discretizes normal derivative jump boundary conditions without smearing jumps in the tangential derivative; a new iterative method for solving linear and nonlinear quasi-steady reaction-diffusion equations; an adaptive discretization to compute the curvature and normal vectors; and a new discrete approximation to the Heaviside function. We present numerical examples that demonstrate better than 1.5-order convergence for problems where traditional ghost cell methods either fail to converge or attain at best sub-linear accuracy. We apply our techniques to a model of tumor growth in complex, heterogeneous tissues that consists of a nonlinear nutrient equation and a pressure equation with geometry-dependent jump boundary conditions. We simulate the growth of glioblastoma (an aggressive brain tumor) into a large, 1 cm square of brain tissue that includes heterogeneous nutrient delivery and varied biomechanical characteristics (white matter, gray matter, cerebrospinal fluid, and bone), and we observe growth morphologies that are highly dependent upon the variations of the tissue characteristics—an effect observed in real tumor growth

    Intracoronary administration of autologous adipose tissue-derived stem cells improves left ventricular function, perfusion, and remodelling after acute myocardial infarction

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    Aims This study was designed to assess whether intracoronary application of adipose tissue-derived stem cells (ADSCs) compared with bone marrow-derived stem cells (BMSCs) and control could improve cardiac function after 30 days in a porcine acute myocardial infarction/reperfusion model. Methods and results An acute transmural porcine myocardial infarction was induced by inflating an angioplasty balloon for 180 min in the mid-left anterior descending artery. Two million cultured autologous stem cells were intracoronary injected through the central lumen of the inflated balloon catheter. Analysis of scintigraphic data obtained after 28 + 3 days showed that both absolute and relative perfusion defect decreased significantly after intracoronary administration of ADSCs or BMSCs (relative 30 or 31%, respectively), compared with carrier administration alone (12%, P ¼ 0.048). Left ventricular ejection fraction after 4 weeks increased significantly more after ADSC and BMSC administration than after carrier administration: 11.39 + 4.62 and 9.59 + 7.95%, respectively vs. 1.95 + 4.7%, P ¼ 0.02). The relative thickness of the ventricular wall in the infarction area after cell administration was significantly greater than that after carrier administration. The vascular density of the border zone also improved. The grafted cells co-localized with von Willebrand factor and alpha-smooth muscle actin and incorporated into newly formed vessels. Conclusion This is the first study to show that not only bone marrow-derived cells but also ADSCs engrafted in the infarct region 4 weeks after intracoronary cell transplantation and improved cardiac function and perfusion via angiogenesis

    Characteristics of high-intensity groundwater abstractions from weathered crystalline bedrock aquifers in East Africa

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    Weathered crystalline bedrock aquifers sustain water supplies across the tropics, including East Africa. Although well yields are commonly <1 L s−1, more intensive abstraction occurs and provides vital urban and agricultural water supplies. The hydrogeological conditions that sustain such high abstraction from crystalline bedrock aquifers remain, however, poorly characterised. Five sites of intensive groundwater abstraction (multiple boreholes yielding several L s−1 or more) were investigated in Uganda and Tanzania. Analysis of aquifer properties data indicates that the sites have transmissivities of 10–1,000 m2 day−1, which is higher than generally observed in deeply weathered crystalline bedrock aquifers. At four of the five sites, weathered bedrock (saprolite) is overlain by younger superficial sediments, which provide additional storage and raise the water table within the underlying aquifer. Residence-time indicators suggest that: (1) abstracted water derives, in part, from modern recharge (within the last 10–60 years); and (2) intensive abstraction is sustained by recharge occurring over several decades. This range of encountered residence times indicates a degree of resilience to contemporary climate variability (e.g. short-term droughts), although the long-term sustainability of intensive abstractions remains uncertain. Evidence from one site in Tanzania (Makutapora) highlights the value of multi-decadal groundwater-level records in establishing the long-term viability of intensive groundwater abstraction, and demonstrates the influence of intra-decadal climate variability in determining the magnitude and frequency of recharge

    Eco arts exhibition by the Uakatakata (heatwave) artists group

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    Pacific cultures and societies are central to the USP mission, vision and values and a theme that permeates every aspect of the Strategic plan. Central to the positioning of the university as the international leader in Pacific Studies, Arts and Culture is the creation of an internally recognized centre for visual and performing arts and pacific heritage which will showcase and promote pacific talent in all areas of art. The idea of an innovative interdisciplinary program, such as the one described here, which draws upon creative expression, community experiences and academic research on climate change to support and underlie these goal

    Predicting drug pharmacokinetics and effect in vascularized tumors using computer simulation

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    In this paper, we investigate the pharmacokinetics and effect of doxorubicin and cisplatin in vascularized tumors through two-dimensional simulations. We take into account especially vascular and morphological heterogeneity as well as cellular and lesion-level pharmacokinetic determinants like P-glycoprotein (Pgp) efflux and cell density. To do this we construct a multi-compartment PKPD model calibrated from published experimental data and simulate 2-h bolus administrations followed by 18-h drug washout. Our results show that lesion-scale drug and nutrient distribution may significantly impact therapeutic efficacy and should be considered as carefully as genetic determinants modulating, for example, the production of multidrug-resistance protein or topoisomerase II. We visualize and rigorously quantify distributions of nutrient, drug, and resulting cell inhibition. A main result is the existence of significant heterogeneity in all three, yielding poor inhibition in a large fraction of the lesion, and commensurately increased serum drug concentration necessary for an average 50% inhibition throughout the lesion (the IC50 concentration). For doxorubicin the effect of hypoxia and hypoglycemia (“nutrient effect”) is isolated and shown to further increase cell inhibition heterogeneity and double the IC50, both undesirable. We also show how the therapeutic effectiveness of doxorubicin penetration therapy depends upon other determinants affecting drug distribution, such as cellular efflux and density, offering some insight into the conditions under which otherwise promising therapies may fail and, more importantly, when they will succeed. Cisplatin is used as a contrast to doxorubicin since both published experimental data and our simulations indicate its lesion distribution is more uniform than that of doxorubicin. Because of this some of the complexity in predicting its therapeutic efficacy is mitigated. Using this advantage, we show results suggesting that in vitro monolayer assays using this drug may more accurately predict in vivo performance than for drugs like doxorubicin. The nonlinear interaction among various determinants representing cell and lesion phenotype as well as therapeutic strategies is a unifying theme of our results. Throughout it can be appreciated that macroscopic environmental conditions, notably drug and nutrient distributions, give rise to considerable variation in lesion response, hence clinical resistance. Moreover, the synergy or antagonism of combined therapeutic strategies depends heavily upon this environment
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