2,804 research outputs found

    Opportunity development process in sustainability entrepreneurship

    Get PDF
    The concept of sustainability has become of major relevance in management literature and business education. It has crossed the boundaries of corporate social responsibility towards new perspectives that stress the necessity of a more holistic approach to entrepreneurial value creation. Although the field of sustainability entrepreneurship has advanced in proving a definition and description of its phenomenon, current literature has so far been unable to capture and explain, both conceptually and empirically, how and why particular individuals decide to pursue opportunities with social and environmental components concurrent with pursuing economic viability. This study tackles this challenge by examining the complex set of conditions that produce the different components of this particular opportunity development process, comprising the development of venture ideas, the organization of entrepreneurial actions and the formation of exchange relationships. Based on an inductive Fuzzy-set Qualitative Comparative Analysis of the opportunity process of 45 sustainable ventures, this study explores 13 different potential conditions for the above outcomes, upon which it identifies necessary conditions and sufficient configurations of conditions that lead to the integration of sustainability in the different stages of the opportunity process. The study provides refined knowledge and theoretical language on complex causation that facilitate the explanation of how this process unfolds based on the logic of necessity and sufficiency. It makes a broader contribution to both theorizing and research design in the study of entrepreneurial processes and outcomes by presenting a systematic and configurational view of entrepreneurial efforts and offering a basis for understanding the integration of sustainability in the development of venture opportunities

    Beyond Financial Performance and Corporate Greening: Mapping out the Research Field of Sustainability Entrepreneurship

    Get PDF
    Sustainability entrepreneurs are seen as key actors in facing contemporary structural problems and creating sustainable growth and wealth. They bring into being a new approach to business opportunities that resolves the dualistic divide between business ventures and altruistic endeavours, in favour of a new logic based on the creation of economic value beyond corporate boundaries while improving the social and ecological environments. Despite the recent surge of research interest on this topic, there remains a lack of understanding of the nature of this phenomenon. Therefore, there is a need to define boundaries, connect theoretical fields and provide deeper explanations of sustainability entrepreneurship beyond current approaches to corporate sustainability and social entrepreneurship. This paper seeks to address some of these issues by focusing on the distinctive importance of sustainability entrepreneurship within entrepreneurship research and developing a conceptual framework aimed at mapping out the field while at the same time adhering to empirical relevance. In doing so, we define sustainability entrepreneurship as the scholarly examination of how and by whom opportunities to create future goods and services are recognised, evaluated, and exploited, while improving the development of society, the economy and the environment, allowing future generations to meet their own needs. Based on this definition, we draw upon literature on entrepreneurship theory and sustainable development and propose three avenues for further research on this topic: theoretical and empirical definition of sustainability entrepreneurs, the process of development of sustainability-oriented venture opportunities and the interaction between institutions and sustainability entrepreneurship. Within each avenue we pose relevant research questions that are of both descriptive and explanatory nature, and aim to bring closer the conceptual and empirical aspects of sustainability entrepreneurship. Focusing on these dimensions and questions helps visualise and analyse currently disparate conditions, features, and outcomes of sustainability entrepreneurship, thus increasing the intensity and quality of future theoretical and empirical work

    Characteristics and racial variations of polypoidal choroidal vasculopathy in tertiary centers in the United States and United Kingdom

    Get PDF
    PURPOSE: To evaluate the characteristics and racial variations amongst patients with polypoidal choroidal vasculopathy (PCV) in the United States and the United Kingdom. METHODS: Fundus photos and indocyanine green angiography images were evaluated in a multicenter retrospective study to establish the diagnosis of PCV. Visual acuity (VA) was recorded in ETDRS letter count. RESULTS: Eighty eyes of 71 PCV patients (average age of 69.4 ± 10.4 years) were included in the analysis. Of the total 71 subjects, 46 (65%) were women, 33 (46.5%) were Blacks, 16 (22.5%) were Whites, 19 (26.8%) were Asians and 3 (4.2%) belonged to other races. The Black subgroup had vision gain of 3.5 letters. The White and Asian subgroups had vision loss of 13.1 and 3.5 letters, respectively. There was female predominance in Blacks (67%), Whites (69%), and Asians (58%). PCV was found to be a bilateral disease in 14 patients (20%). There was significant decrease of 7 letters with every decade increase in age (p = 0.005). Final VA was worse in males when compared to females (p = 0.042), and worse in Whites when compared to Blacks (p = 0.005). For every 10 letters worse in initial VA upon diagnosis with PCV, the final VA was worse by 6 letters (p < 0.001). The location of the polypoidal lesion within the macula was associated with significant decrease of 14 letters in BCVA (p = 0.02). The length of follow up was significantly associated with worse visual outcome (p = 0.012). Final VA had no significant correlation with the lens status, or the different treatment modalities. CONCLUSIONS: Based on our cohort from tertiary centers in the United States and United Kingdom, PCV is a bilateral disease in one-fifth of patients. It features a variable female predominance based on ethnicity. Increased age, worse vision upon initial presentation, longer follow up and macular location of the polyp were associated with worse visual outcome

    THE HIGH CADENCE TRANSIENT SURVEY (HITS). I. SURVEY DESIGN AND SUPERNOVA SHOCK BREAKOUT CONSTRAINTS

    Get PDF
    Indexación: Web of Science; Scopus.We present the first results of the High Cadence Transient Survey (HiTS), a survey for which the objective is to detect and follow-up optical transients with characteristic timescales from hours to days, especially the earliest hours of supernova (SN) explosions. HiTS uses the Dark Energy Camera and a custom pipeline for image subtraction, candidate filtering and candidate visualization, which runs in real-time to be able to react rapidly to the new transients. We discuss the survey design, the technical challenges associated with the real-time analysis of these large volumes of data and our first results. In our 2013, 2014, and 2015 campaigns, we detected more than 120 young SN candidates, but we did not find a clear signature from the short-lived SN shock breakouts (SBOs) originating after the core collapse of red supergiant stars, which was the initial science aim of this survey. Using the empirical distribution of limiting magnitudes from our observational campaigns, we measured the expected recovery fraction of randomly injected SN light curves, which included SBO optical peaks produced with models from Tominaga et al. (2011) and Nakar & Sari (2010). From this analysis, we cannot rule out the models from Tominaga et al. (2011) under any reasonable distributions of progenitor masses, but we can marginally rule out the brighter and longer-lived SBO models from Nakar & Sari (2010) under our best-guess distribution of progenitor masses. Finally, we highlight the implications of this work for future massive data sets produced by astronomical observatories, such as LSST.http://iopscience.iop.org/article/10.3847/0004-637X/832/2/155/meta;jsessionid=76BDFFFE378003616F6DBA56A9225673.c4.iopscience.cld.iop.or

    A pseudo-randomised clinical trial of in situ gels of fluconazole for the treatment of oropharngeal candidiasis

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Oropharyngeal candidasis is a common opportunistic infection seen in immunocompromised patients. Fluconazole has a broad spectrum antifungal activity including a wide variety of <it>candida </it>species. Aim of the present investigation was to formulate and find out the relative efficacy of <it>in situ </it>gels of fluconazole.</p> <p>Method</p> <p>The <it>in situ </it>gels were prepared using polymers which exhibited sol-to-gel phase transition due to change in specific physico-chemical parameters, such as ion triggered system using gellan gum (0.5% w/v) along with sodium carboxylmethylcellulose (0.35%w/v). The study design was bicenter, 'pseudo-randomised, single blind trial conducted in Mangalore., India, which includes 15 HIV positive patients, 15 patients with partial or completes dentures, and 15 patients who were treated with (active control) fluconazole tablets 100 mg/day for 14 days. Severity of disease was scored clinically before treatment and at clinical evaluations on day 3, 7, 14, 18, 21, 35, and 42. Semiquantitative microbiological cultures of oral swabs were also obtained on same days.</p> <p>Results</p> <p>All patients had mycological documented oropharyngeal candidiasis and were treated with fluconazole (0.5%w/v) <it>in situ </it>gels for 14 days Severity of disease was scored clinically before treatment and at different predetermined time intervals along with semi quantitative culture of oral swabs. The clinical response rate showed 97% cure after 14 days in the treated with <it>in situ </it>gel. In comparison, the control group treated with fluconazole tablets showed 85% improvement in symptoms of oral candidiasis. The patients suffering from HIV infection showed relapse in oral candidiasis at the end of 21 days. The patients having oral candidiasis due to partial or complete dentures showed complete recovery and were free from signs and symptoms of oral candidiasis.</p> <p>Conclusions</p> <p>The <it>in situ </it>gel formulation of fluconazole was well tolerated with no severe adverse reaction and offers a better alternative to tablet formulation in the treatment of oropharyngeal candidasis.</p> <p>Trial registration</p> <p>Current Controlled Trails <a href="http://www.controlled-trials.com/ISRCTN90634047">ISRCTN90634047</a></p

    Interleukin 7 from Maternal Milk Crosses the Intestinal Barrier and Modulates T- Cell Development in Offspring

    Get PDF
    Background Breastfeeding protects against illnesses and death in hazardous environments, an effect partly mediated by improved immune function. One hypothesis suggests that factors within milk supplement the inadequate immune response of the offspring, but this has not been able to account for a series of observations showing that factors within maternally derived milk may supplement the development of the immune system through a direct effect on the primary lymphoid organs. In a previous human study we reported evidence suggesting a link between IL-7 in breast milk and the thymic output of infants. Here we report evidence in mice of direct action of maternally-derived IL-7 on T cell development in the offspring. Methods and Findings  We have used recombinant IL-7 labelled with a fluorescent dye to trace the movement in live mice of IL-7 from the stomach across the gut and into the lymphoid tissues. To validate the functional ability of maternally derived IL- 7 we cross fostered IL-7 knock-out mice onto normal wild type mothers. Subsets of thymocytes and populations of peripheral T cells were significantly higher than those found in knock-out mice receiving milk from IL-7 knock-out mothers. Conclusions/Significance Our study provides direct evidence that interleukin 7, a factor which is critical in the development of T lymphocytes, when maternally derived can transfer across the intestine of the offspring, increase T cell production in the thymus and support the survival of T cells in the peripheral secondary lymphoid tissue

    Parity-Violating Electron Scattering from 4He and the Strange Electric Form Factor of the Nucleon

    Full text link
    We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from ^4He at an average scattering angle = 5.7 degrees and a four-momentum transfer Q^2 = 0.091 GeV^2. From these data, for the first time, the strange electric form factor of the nucleon G^s_E can be isolated. The measured asymmetry of A_PV = (6.72 +/- 0.84 (stat) +/- 0.21 (syst) parts per million yields a value of G^s_E = -0.038 +/- 0.042 (stat) +/- 0.010 (syst), consistent with zero

    A competitive integration model of exogenous and endogenous eye movements

    Get PDF
    We present a model of the eye movement system in which the programming of an eye movement is the result of the competitive integration of information in the superior colliculi (SC). This brain area receives input from occipital cortex, the frontal eye fields, and the dorsolateral prefrontal cortex, on the basis of which it computes the location of the next saccadic target. Two critical assumptions in the model are that cortical inputs are not only excitatory, but can also inhibit saccades to specific locations, and that the SC continue to influence the trajectory of a saccade while it is being executed. With these assumptions, we account for many neurophysiological and behavioral findings from eye movement research. Interactions within the saccade map are shown to account for effects of distractors on saccadic reaction time (SRT) and saccade trajectory, including the global effect and oculomotor capture. In addition, the model accounts for express saccades, the gap effect, saccadic reaction times for antisaccades, and recorded responses from neurons in the SC and frontal eye fields in these tasks. © The Author(s) 2010

    An unusual presentation of Castleman's Disease:a case report

    Get PDF
    BACKGROUND: Castleman's disease (CD), a rare condition of uncertain etiology, involves a massive proliferation of lymphoid tissues and typically presents as mediastinal masses. We describe a patient with CD who presented with diffuse adenopathy involving the inguinal, paratracheal, retroperitoneal, axillary, and pelvic regions. CASE PRESENTATION: Case report describing presentation, work-up, management and clinical course of a patient with Castleman's disease in the setting of a county hospital in metropolitan area. Patient was treated with chemotherapeutic agents. CONCLUSIONS: To our knowledge, this represents the first case of CD involving an HIV-positive patient with a negative Human Herpes Virus (HHV-8) viral panel. Because patients with similar clinical histories are at high risk for the development of non-Hodgkin's lymphoma and Kaposi sarcoma, regular medical surveillance is recommended
    corecore