Background: Since the spread of Corona Virus Disease 19 most African countries have embarked on a system of either total or partial lockdown and have used it as a tool for curbing the spread of COVID-19. This study examines whether lockdown can be of help and whether it is any of the public health policies that can bring massive and tremendous change to health systems and general economy of African countries using it as a way of intervention to curb the spread of COVID-19. Method:The researchers reviewed some literature about world economies with Google as the main search tool. They also listened to press conferences, editorial reviews from the African Union, World Bank, International Monetary Fund, and the World Health Organization. Interviews were also done through phone calls, questions asked via emails to some of the world's leading epidemiologists, infectious disease specialists in the United States of America, Europe, Africa, and some of the listed countries in their work.Results: After a careful study and analysis of countries like Hong Kong, South Korea, Japan, Singapore, Taiwan who did not really make lock down as a major measure in fighting the COVID-19 disease still saw a stable economy, a drastic containment of the pandemic, few deaths and more recoveries as compared to countries in Africa like south Africa which is the worst affected African country,

The bond mechanism between concrete and steel is an important input parameter in the design of reinforced concrete elements. The reuse of waste materials as aggregates in concrete has led to the discovery of different types of concrete with unique bond characteristics. This paper reports on the bond characteristics of concrete produced from waste automobile tire chips and palm kernel shell aggregates and deformed mild steel rebars. A total of 125 concrete cubes (150 x 150 x 150mm) with metal inserts were cast from 21 concrete mixes with varied content of PKS and waste automobile tire aggregates. Pullout test was carried out to evaluate the strength of the bond mechanism between the steel and the various concrete mixes. The results revealed that bond strength decreased with increasing PKS and tire content. Moreover, increasing the bar size and embedment length reduced the bond stress. The ratio of the bond stress and compressive strength was found to be averagely 63.88%. Regarding the bond failure mechanism, it was identified that failure of the specimen occurred through either rebar pullout or tensile splitting of the concrete. Based on the results obtained, it was concluded that PKS and tire can be used as partial replacement of granite aggregates in concrete since the resultant concrete can develop adequate bond with steel bars in structural applications.

Introduction: Outpatient parenteral antibiotic treatment (OPAT) is associated with shorter length of hospital stay and reduced cost. Yet, patients discharged home on OPAT are at risk of hospital readmissions due to adverse events and complications. Although the impact of a multidisciplinary approach to readmission has been assessed by previous studies, addition of an innovative technology has not been evaluated for OPAT. This study examines the impact of a multidisciplinary approach including automated voice calls on 30-day readmissions of OPAT patients. Methods: A post-discharge transitional care process (PDTCP) targeting OPAT patients was implemented in fall 2016. This process included an automated telephone patient engagement service and coordination among pharmacy, nursing, medicine, and social work personnel. The patients on OPAT received automated telephone calls at 2, 9, 16, 28, and 40 days post-discharge to ensure medication availability and adherence and to circumvent issues that would otherwise result in an emergency room visit or readmission to the hospital. Results: A total 429 voice calls were made to 148 patients from November 8, 2016 to February 28, 2019. Overall, 61% (n = 90/148) of the patients were successfully reached by the automated voice system. The patients who were reached by the automated voice system were less likely to be readmitted than those not reached (18.9% vs 41.4%; relative risk (RR) 0.46, 95% CI 0.27-0.77, P = .003). Conclusion: Our study demonstrated that a multidisciplinary approach involving the use of automated telephone calls was associated with decreased hospital readmissions.

Measurements of nanoparticle size distributions are crucial for many advanced applications. Detection efficiency often scales non-linearly with diameter and this diminishes the accuracy of determinations in a range smaller than tens of nanometers.As a result, the accurate classification of broadly distributed systems requires very large numbers of measurements. This presents a problem for conventional techniques, which are labour intensive, and so have low throughput. Progress in many areas of nanotechnology requires a faster, lower-cost and more accurate measure of particle size distributions, particularly for diameters smaller than 20 nm. Here, we present a tailored interferometric microscope system, combined with a high-speed image-processing strategy, optimized for real-time particle tracking that determines accurate size distributions in nominal 5, 10 and 15 nm colloidal gold nanoparticle systems by automatically sensing and classifying thousands of single particles in solution at rates as high as 4,000 particles per minute. We demonstrate this method by sensing the irreversible binding of gold nanoparticles to poly-D-lysine functionalized coverslips. Variations in the single particle signal as a function of mass and time show clear evidence for the presence of diffusion-limited transport that most affects larger particles in solution.

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. Boston University African Studies Center andBoard of Trustees, Boston University are collaborating with JSTOR to digitize, preserve and extend access to The International Journal of African Historical Studies. All use subject to JSTOR Terms and Conditions 570 BOOK REVIEWS A POLITICAL GEOGRAPHY OF AFRICA. By E. Amano Boateng. Cambridge: Cambridge University Press, 1978. Pp. xlx, 292; 34 figures.The need for a good scholarly treatment of the political geography of the continent with the largest number of states is undoubtedly great. Unfortunately this isn't it. Instead Boateng gives us an unimaginative, dull, and sometimes incoherent rehash of African political history from secondary sources. In the first chapter, devoted to the meaning and scope of political geography, Boateng informs us that "we may define political geography as the study of those aspects of the geography of politically organized areas which are relevant to the existence and effective functioning of the area concerned as political entities both internally and in their external relationships" (p. 6). He follows this by the statement that "our principal concern must be with the territorial rather than with the purely political aspects" (p. 7). Earlier he has drawn attention to the fact that the subject includes consideration of all political entities, including the internal hierarchy of administrative areas (p. 5), that relationships among territories are strongly conditioned by existing means of transport and communication (pp. 5-6), and that the reduction and elimination of conflict must engage the attention of political geographers (p. 6).His is a fair description of a subje6t notably difficult to define. Within the scope outlined, geographers clearly have much to contribute to the scholarly discussion of African politics, especially since other social scientists frequently appear unconcerned if not oblivious to spatial relationships. Unfortunately Boateng does not take his own prescription, and we lear very little about territorial history, transport, or internal political structures.Boateng uses his second chapter to introduce us to a number of concepts and terms, what he calls the "elements of political geography." Thus we learn about the importance of accessibility (p. 11), which has a specific quantifiable meaning to geographers. We are introduced to the concepts of "enclave, exclave, glacis," and "corridor" (p. 11, and fig. 1). He provides a mathematical compactness formula for the relationship of size and shape of areas