Network diversity structure closeness and innovation of South African micro-entrepreneurs

This study qualitatively explores the embeddedness of the innovation process of South African microbusinesses by investigating how small local entrepreneurs in the Greater Johannesburg area utilise their social networks to source entrepreneurial value. A comparative grounded theory analysis enabled the original conceptualisation of Network Diversity Structure and formulates the central proposition that the network dimensions of diversity and closeness enable the innovation process among manufacturing microbusinesses more so than in service microbusinesses. Furthermore, the study proposes that both a structural and relational/experiential dimension of closeness, enables micro-entrepreneurs to create meaning and knowledge collaboratively with other entrepreneurs and actors. This socially facilitated process of exchanging ideas, information, and resources is central to the innovation process of firms traditionally limited by both their size and historical social institutions

Network diversity structure, closeness and innovation of South African micro-entrepreneurs

This study qualitatively explores the embeddedness of the innovation process of South African microbusinesses by investigating how small local entrepreneurs in the Greater Johannesburg area utilise their social networks to source entrepreneurial value. A comparative grounded theory analysis enabled the original conceptualisation of Network Diversity Structure and formulates the central proposition that the network dimensions of diversity and closeness enable the innovation process among manufacturing microbusinesses more so than in service microbusinesses. Furthermore, the study proposes that both a structural and relational/experiential dimension of closeness, enables micro-entrepreneurs to create meaning and knowledge collaboratively with other entrepreneurs and actors. This socially facilitated process of exchanging ideas, information, and resources is central to the innovation process of firms traditionally limited by both their size and historical social institutions

The Dialectics of the Blueberry Muffin: Towards a Philosophy of Love

This dissertation study was a process where I purposed my life in the personal, educational, and societal contexts within three periods in my life: high school, college, and graduate school. My conceptual framework draws on the writings of Paulo Freire and Martin Luther King Jr., bell hooks, Cornel West, and Maulana Karenga because their works seek to understand contradictions that limit human beings from living up to their human potential. Although their works are similar, they have different foci. Freire and Karenga's writings are driven by a humanist desire to human transformation, while King's, hooks', and West's works are rooted in a theological foundation for individual transformation. All of the scholars embed love within their writings, which they declare is essential to individuals working to assist in the development of a better world. For my methodology, I use autobiographical writing, which allowed me to reflect on my personal, educational, and societal contradiction within three periods in my life: high school, college, and graduate school. Upon reflecting on my life, I analyzed it using my conceptual framework. The result of my dissertation project was the creation of a philosophical framework I call Transconceptualization. This framework seeks to understand the self in the past and present in order to move beyond contradictions to live a new life in the present and future

Nisin inducible production of listeriolysin O in Lactococcus lactis NZ9000

<p>Abstract</p> <p>Background</p> <p><it>Listeria monocytogenes </it>is a well-characterized food-borne pathogen that infects pregnant women and immunocompromised individuals. Listeriolysin O (LLO) is the major virulence factor of the pathogen and is often used as a diagnostic marker for detection of <it>L. monocytogenes</it>. In addition, LLO represents a potent antigen driving T cell-mediated immunity during infection. In the present work, <it>Lactococcus lactis </it>NZ9000 was used as an expression host to hyper-produce LLO under inducible conditions using the NICE (NIsin Controlled Expression) system. We created a modified pNZ8048 vector encoding a six-His-tagged LLO downstream of the strong inducible PnisA promoter.</p> <p>Results</p> <p>The constructed vector (pNZPnisA:CYTO-LLO) was expressed in <it>L. lactis </it>NZ9000 and was best induced at mid-log phase with 0.2% v/v nisin for 4 h statically at 30°C. Purification of the His-tagged LLO was accomplished by Ni-NTA affinity chromatography and functionality was confirmed through haemolytic assays. Total LLO yield (measured as total protein content) was 4.43–5.9 mg per litre culture and the haemolytic activity was still detectable after 8 months of storage at 4°C.</p> <p>Conclusion</p> <p>The LLO production method described in this work provides an approach to efficient LLO production in the Gram-positive <it>Lactococcus </it>bacterium to yield a significant source of the protein for research and diagnostic applications. Expression of LLO in <it>L. lactis </it>has a number of benefits over <it>E. coli </it>which may facilitate both <it>in vivo </it>and <it>in vitro </it>applications of this system.</p

Network-based resources for the innovation process of South African micro-entrepreneurs: A conceptual framework

The paper explores the social networks of South African micro-entrepreneurs in order to understand the socially-embedded resources that micro-entrepreneurs apply towards their innovation process. The paper posits that the social capital embedded within the network of a micro-entrepreneur is activated by the demands of the innovation process to generate other forms of resources by which the innovation process is facilitated. Analysing empirical data collected via in-depth interviews of urban micro-entrepreneurs in the Johannesburg metropolitan area, the analysis conceptually organizes these various forms of socially embedded resources into an original framework referred to as Network Diversity Value (NDV). Two central dimensions frame NDV – the orientation of the innovation process and the form of the emerging resource. The interaction of these dimensions reveal a variety of network-based resources perceived as valuable, and suggest a greater degree of complexity and nuance in the South African micro-entrepreneur’s innovative process than that which common discourse conveys

Two-divisibility of the coefficients of certain weakly holomorphic modular forms

We study a canonical basis for spaces of weakly holomorphic modular forms of weights 12, 16, 18, 20, 22, and 26 on the full modular group. We prove a relation between the Fourier coefficients of modular forms in this canonical basis and a generalized Ramanujan tau-function, and use this to prove that these Fourier coefficients are often highly divisible by 2.Comment: Corrected typos. To appear in the Ramanujan Journa

A reference relative time-scale as an alternative to chronological age for cohorts with long follow-up

Background: Epidemiologists have debated the appropriate time-scale for cohort survival studies; chronological age or time-on-study being two such time-scales. Importantly, assessment of risk factors may depend on the choice of time-scale. Recently, chronological or attained age has gained support but a case can be made for a ‘reference relative time-scale’ as an alternative which circumvents difficulties that arise with this and other scales. The reference relative time of an individual participant is the integral of a reference population hazard function between time of entry and time of exit of the individual. The objective here is to describe the reference relative time-scale, illustrate its use, make comparison with attained age by simulation and explain its relationship to modern and traditional epidemiologic methods. Results: A comparison was made between two models; a stratified Cox model with age as the time-scale versus an un-stratified Cox model using the reference relative time-scale. The illustrative comparison used a UK cohort of cotton workers, with differing ages at entry to the study, with accrual over a time period and with long follow-up. Additionally, exponential and Weibull models were fitted since the reference relative time-scale analysis need not be restricted to the Cox model. A simulation study showed that analysis using the reference relative time-scale and analysis using chronological age had very similar power to detect a significant risk factor and both were equally unbiased. Further, the analysis using the reference relative time-scale supported fully-parametric survival modelling and allowed percentile predictions and mortality curves to be constructed. Conclusions: The reference relative time-scale was a viable alternative to chronological age, led to simplification of the modelling process and possessed the defined features of a good time-scale as defined in reliability theory. The reference relative time-scale has several interpretations and provides a unifying concept that links contemporary approaches in survival and reliability analysis to the traditional epidemiologic methods of Poisson regression and standardised mortality ratios. The community of practitioners has not previously made this connection

Community-based intervention packages for reducing maternal and neonatal morbidity and mortality and improving neonatal outcomes

Background: While maternal, infant and under-five child mortality rates in developing countries have declined significantly in the past two to three decades, newborn mortality rates have reduced much more slowly. While it is recognised that almost half of the newborn deaths can be prevented by scaling up evidence-based available interventions such as tetanus toxoid immunisation to mothers, clean and skilled care at delivery, newborn resuscitation, exclusive breastfeeding, clean umbilical cord care, management of infections in newborns, many require facility based and outreach services. It has also been stated that a significant proportion of these mortalities and morbidities could also be potentially addressed by developing community-based packages interventions which should also be supplemented by developing and strengthening linkages with the local health systems. Some of the recent community-based studies of interventions targeting women of reproductive age have shown variable impacts on maternal outcomes and hence it is uncertain if these strategies have consistent benefit across the continuum of maternal and newborn care.Objectives: To assess the effectiveness of community-based intervention packages in reducing maternal and neonatal morbidity and mortality, and improving neonatal outcomes.Search strategy: We searched The Cochrane Pregnancy and Childbirth Group\u27s Trials Register (January 2010), World Bank\u27s JOLIS (12 January 2010), BLDS at IDS and IDEAS database of unpublished working papers (12 January 2010), Google and Google Scholar (12 January 2010). Selection criteria: All prospective randomised and quasi-experimental trials evaluating the effectiveness of community-based intervention packages in reducing maternal and neonatal mortality and morbidities, and improving neonatal outcomes.Data collection and analysis: Two review authors independently assessed trial quality and extracted the data.Main results:The review included 18 cluster-randomised/quasi-randomised trials, covering a wide range of interventional packages, including two subsets from one trial. We incorporated data from these trials using generic inverse variance method in which logarithms of risk ratio estimates were used along with the standard error of the logarithms of risk ratio estimates. Our review did not show any reduction in maternal mortality (risk ratio (RR) 0.77, 95% confidence interval (CI) 0.59 to 1.02, random-effects (10 studies, n = 144,956), I(2) 39%, P value 0.10. However, significant reduction was observed in maternal morbidity (RR 0.75, 95% CI 0.61 to 0.92, random-effects (four studies, n = 138,290), I(2) 28%, neonatal mortality (RR 0.76, 95% CI 0.68 to 0.84, random-effects (12 studies, n = 136,425), I(2) 69%, P value \u3c 0.001), stillbirths (RR 0.84, 95% CI 0.74 to 0.97, random-effects (11studies, n = 113,821), I(2) 66%, P value 0.001) and perinatal mortality (RR 0.80, 95% CI 0.71 to 0.91, random-effects (10 studies, n = 110,291), I(2) 82%, P value \u3c 0.001) as a consequence of implementation of community-based interventional care packages. It also increased the referrals to health facility for pregnancy related complication by 40% (RR 1.40, 95% CI 1.19 to 1.65, fixed-effect (two studies, n = 22,800), I(2) 0%, P value 0.76), and improved the rates of early breastfeeding by 94% (RR 1.94, 95% CI 1.56 to 2.42, random-effects (six studies, n = 20,627), I(2) 97%, P value \u3c 0.001). We assessed our primary outcomes for publication bias, but observed no such asymmetry on the funnel plot.Authors\u27Conclusion:Our review offers encouraging evidence of the value of integrating maternal and newborn care in community settings through a range of interventions which can be packaged effectively for delivery through a range of community health workers and health promotion groups. While the importance of skilled delivery and facility-based services for maternal and newborn care cannot be denied, there is sufficient evidence to scale up community-based care through packages which can be delivered by a range of community-based workers

Hemispheric symptoms and carotid plaque echomorphology

AbstractPurpose: In patients with carotid bifurcation disease, the risk of stroke mainly depends on the severity of the stenosis, the presenting hemispheric symptom, and, as recently suggested, on plaque echodensity. We tested the hypothesis that asymptomatic carotid plaques and plaques of patients who present with different hemispheric symptoms are related to different plaque structure in terms of echodensity and the degree of stenosis. Methods: Two hundred sixty-four patients with 295 carotid bifurcation plaques (146 symptomatic, 149 asymptomatic) causing more than 50% stenosis were examined with duplex scanning. Thirty-six plaques were associated with amaurosis fugax (AF), 68 plaques were associated with transient ischemic attacks (TIAs), and 42 plaques were associated with stroke. B-mode images were digitized and normalized using linear scaling and two reference points, blood and adventitia. The gray scale median (GSM) of blood was set to 0, and the GSM of the adventitia was set to 190 (gray scale range, black = 0; white = 255). The GSM of the plaque in the normalized image was used as the objective measurement of echodensity. Results: The mean GSM and the mean degree of stenosis, with 95% confidence intervals, for plaques associated with hemispheric symptoms were 13.3 (10.6 to 16) and 80.5 (78.3 to 82.7), respectively; and for asymptomatic plaques, the mean GSM and the mean degree of stenosis were 30.5 (26.2 to 34.7) and 72.2 (69.8 to 74.5), respectively. Furthermore, in plaques related to AF, the mean GSM and the mean degree of stenosis were 7.4 (1.9 to 12.9) and 85.6 (82 to 89.2), respectively; in those related to TIA, the mean GSM and the mean degree of stenosis were 14.9 (11.2 to 18.6) and 79.3 (76.1 to 82.4), respectively; and in those related to stroke, the mean GSM and the mean degree of stenosis were 15.8 (10.2 to 21.3) and 78.1 (73.4 to 82.8), respectively. Conclusion: Plaques associated with hemispheric symptoms are more hypoechoic and more stenotic than those associated with no symptoms. Plaques associated with AF are more hypoechoic and more stenotic than those associated with TIA or stroke or those without symptoms. Plaques causing TIA and stroke have the same echodensity and the same degree of stenosis. These findings confirm previous suggestions that hypoechoic plaques are more likely to be symptomatic than hyperechoic ones. They support the hypothesis that the pathophysiologic mechanism for AF is different from that for TIA and stroke. (J Vasc Surg 2000;31:39-49.

Use of HIV Case Surveillance System to Design and Evaluate Site-Randomized Interventions in an HIV Prevention Study: HPTN 065

Introduction: Modeling studies suggest intensified HIV testing, linkage-to-care and antiretroviral treatment to achieve viral suppression may reduce HIV transmission and lead to control of the epidemic. To study implementation of strategy, population-level data are needed to monitor outcomes of these interventions. US HIV surveillance systems are a potential source of these data. Methods: HPTN065 (TLC-Plus) Study is evaluating the feasibility of a test, linkage-to-care, and treat strategy for HIV prevention in two intervention communities - the Bronx, NY, and Washington, DC. Routinely collected laboratory data on diagnosed HIV cases in the national HIV surveillance system were used to select and randomize sites, and will be used to assess trial outcomes. Results: To inform study randomization, baseline data on site-aggregated study outcomes was provided from HIV surveillance data by New York City and Washington D.C. Departments of Health. The median site rate of linkage-to-care for newly diagnosed cases was 69% (IQR 50%-86%) in the Bronx and 54% (IQR 33%-71%) in Washington, D.C. In participating HIV care sites, the median site percent of patients with viral suppression (<400 copies/mL) was 57% (IQR 53%-61%) in the Bronx and 64% (IQR 55%-72%) in Washington, D.C. Conclusions: In a novel use of site-aggregated surveillance data, baseline data was used to design and evaluate site randomized studies for both HIV test and HIV care sites. Surveillance data have the potential to inform and monitor sitelevel health outcomes in HIV-infected patients