143 research outputs found
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Venture capital contracting in theory and practice: Implications for entrepreneurship research
This article provides a comprehensive theoretical and empirical literature review of venture capital contracts. This outlines the differences between theoretical and practical uses of contract designs; that is, (1) how does the choice of securities give rise to different adverse selection problems in terms of attracting different types of entrepreneurial companies; how does the choice of securities in conjunction with cash flow and control rights provisions affect (2) the effort levels by the entrepreneur and the investor; and (3) ultimately affect entrepreneurial outcomes. This article highlights the major discrepancies between theory and practice and points out potential avenues for further research
Floating stones off El Hierro, Canary Islands: xenoliths of pre-island sedimentary origin in the early products of the October 2011 eruption
The eruption that started off the south coast of El Hierro, Canary Islands, in October 2011 has emitted intriguing eruption products found floating in the sea. These specimens appeared as floating volcanic "bombs" that have in the meantime been termed "restingolites" (after the close-by village of La Restinga) and exhibit cores of white and porous pumice-like material. Currently the nature and origin of these "floating stones" is vigorously debated among researchers, with important implications for the interpretation of the hazard potential of the ongoing eruption. The "restingolites" have been proposed to be either (i) juvenile high-silica magma (e.g. rhyolite), (ii) remelted magmatic material (trachyte), (iii) altered volcanic rock, or (iv) reheated hyaloclastites or zeolite from the submarine slopes of El Hierro. Here, we provide evidence that supports yet a different conclusion. We have collected and analysed the structure and composition of samples and compared the results to previous work on similar rocks found in the archipelago. Based on their high silica content, the lack of igneous trace element signatures, and the presence of remnant quartz crystals, jasper fragments and carbonate relicts, we conclude that "restingolites" are in fact xenoliths from pre-island sedimentary rocks that were picked up and heated by the ascending magma causing them to partially melt and vesiculate. They hence represent messengers from depth that help us to understand the interaction between ascending magma and crustal lithologies in the Canary Islands as well as in similar Atlantic islands that rest on sediment/covered ocean crust (e.g. Cape Verdes, Azores). The occurrence of these "restingolites" does therefore not indicate the presence of an explosive high-silica magma that is involved in the ongoing eruption
Acceptance, Prevalence and Indications for Robot-Assisted Laparoscopy - Results of a Survey Among Urologists in Germany, Austria and Switzerland
Background: Robotic-assisted laparoscopy (RAL) is being widely accepted in the field of urology as a replacement for conventional laparoscopy (CL). Nevertheless, the process of its integration in clinical routines has been rather spontaneous. Objective: To determine the prevalence of robotic systems (RS) in urological clinics in Germany, Austria and Switzerland, the acceptance of RAL among urologists as a replacement for CL and its current use for 25 different urological indications. Materials and Methods: To elucidate the practice patterns of RAL, a survey at hospitals in Germany, Austria and Switzerland was conducted. All surgically active urology departments in Germany (303), Austria (37) and Switzerland (84) received a questionnaire with questions related to the one-year period prior to the survey. Results: The response rate was 63%. Among the participants, 43% were universities, 45% were tertiary care centres, and 8% were secondary care hospitals. A total of 60 RS (Germany 35, Austria 8, Switzerland 17) were available, and the majority (68%) were operated under public ownership. The perception of RAL and the anticipated superiority of RAL significantly differed between robotic and non-robotic surgeons. For only two urologic indications were more than 50% of the procedures performed using RAL: pyeloplasty (58%) and transperitoneal radical prostatectomy (75%). On average, 35% of robotic surgeons and only 14% of non-robotic surgeons anticipated RAL superiority in some of the 25 indications. Conclusions: This survey provides a detailed insight into RAL implementation in Germany, Austria and Switzerland. RAL is currently limited to a few urological indications with a small number of high-volume robotic centres. These results might suggest that a saturation of clinics using RS has been achieved but that the existing robotic capacities are being utilized ineffectively. The possible reasons for this finding are discussed, and certain strategies to solve these problems are offered
RadioActive101-Learning through radio, learning for life: an international approach to the inclusion and non-formal learning of socially excluded young people
This article describes an original international approach to inclusion and non-formal learning of socially excluded young people, through participatory internet radio - RadioActive101. First, we critically discuss the social and digital exclusion of young people. We then describe our approach - that includes partic-ipatory action research methods that are influenced by the work of Dewey and Freire, and operate as a process of complex intervention. This supports the inclusive co-production of radio content in ways that support non-formal learning in two EU contexts – the UK and Portugal. We then summarise and compare a qualitative investigation of RadioActive101. This showed positive results, with important similarities and differences between the two contexts. Participants reported that RadioActive101 was motivating and contributed to the development of contemporary skills, and also stimulated improvements in psychosocial dimensions such as confidence (self-efficacy) and self-esteem. This investigation informed the development of an original recog-nition system for non-formal learning that maps EU Key Competences for Lifelong Learning to radio practic-es and activities that are recognised through electronic badges. Our final reflections emphasise that in order to support the non-formal learning of socially excluded young people we must foreground our attention to foster-ing psychosocial dimensions alongside developing contemporary competences
Intergenerational family support for ‘Generation Rent’:The family home for socially disengaged young people
This paper critically discusses the concept of intergenerational family support in housing for young people. Recognizing increased difficulties faced by the younger generation in the housing market, this paper highlights that support from older family members is increasingly important. Nonetheless, it is critiqued that the role of the family home has been largely ignored in the current ‘generation rent’ discourse. By drawing on recent youth studies debates, this paper argues living in the family home could be an important form of support in housing, especially for marginalized youth. This paper presents insights from qualitative studies in Hong Kong and Scotland and analyses interview accounts of socially disengaged young people. It reflects how remaining at the family home could be interpreted as intergenerational support, and further elicits complexities in expectations, negotiations and emotions involved. This analysis offers new evidence and a more nuanced perspective of intergenerational family support in housing research
The use of a biphasic calcium phosphate in a maxillary sinus floor elevation procedure: a clinical, radiological, histological, and histomorphometric evaluation with 9- and 12-month healing times
Decrease in thyroid adenoma associated (THADA) expression is a marker of dedifferentiation of thyroid tissue
<p>Abstract</p> <p>Background</p> <p><it>Thyroid adenoma associated (THADA) </it>has been identified as the target gene affected by chromosome 2p21 translocations in thyroid adenomas, but the role of THADA in the thyroid is still elusive. The aim of this study was to quantify <it>THADA </it>gene expression in normal tissues and in thyroid hyper- and neoplasias, using real-time PCR.</p> <p>Methods</p> <p>For the analysis <it>THADA </it>and 18S rRNA gene expression assays were performed on 34 normal tissue samples, including thyroid, salivary gland, heart, endometrium, myometrium, lung, blood, and adipose tissue as well as on 85 thyroid hyper- and neoplasias, including three adenomas with a 2p21 translocation. In addition, <it>NIS </it>(<it>sodium-iodide symporter</it>) gene expression was measured on 34 of the pathological thyroid samples.</p> <p>Results</p> <p>Results illustrated that <it>THADA </it>expression in normal thyroid tissue was significantly higher (<it>p </it>< 0.0001, exact Wilcoxon test) than in the other tissues. Significant differences were also found between non-malignant pathological thyroid samples (goiters and adenomas) and malignant tumors (<it>p </it>< 0.001, Wilcoxon test, t approximation), anaplastic carcinomas (ATCs) and all other samples and also between ATCs and all other malignant tumors (<it>p </it>< 0.05, Wilcoxon test, t approximation). Furthermore, in thyroid tumors <it>THADA </it>mRNA expression was found to be inversely correlated with <it>HMGA2 </it>mRNA. <it>HMGA2 </it>expression was recently identified as a marker revealing malignant transformation of thyroid follicular tumors. A correlation between <it>THADA </it>and <it>NIS </it>has also been found in thyroid normal tissue and malignant tumors.</p> <p>Conclusions</p> <p>The results suggest <it>THADA </it>being a marker of dedifferentiation of thyroid tissue.</p
Syndromes with congenital brittle bones
BACKGROUND: There is no clear definition of osteogenesis imperfecta (OI). The most widely used classification of OI divides the disease in four types, although it has been suggested that there may be at least 12 forms of OI. These forms have been named with numbers, eponyms or descriptive names. Some of these syndromes can actually be considered congenital forms of brittle bones resembling OI (SROI). DISCUSSION: A review of different syndromes with congenital brittle bones published in the literature is presented. Syndromes are classified in "OI" (those secondary to mutations in the type I pro-collagen genes), and "syndromes resembling OI" (those secondary to mutations other that the type I pro-collagen genes, identified or not). A definition for OI is proposed as a syndrome of congenital brittle bones secondary to mutations in the genes codifying for pro-collagen genes (COL1A1 and COL1A2). SUMMARY: A debate about the definition of OI and a possible clinical and prognostic classification are warranted
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The Transformation of Citizenship in Complex Societies
The main purpose of this paper is to propose a theoretical framework for understanding the transformation of citizenship in complex societies. To this end, the paper is divided into six sections. The first section elucidates the main reasons for the renaissance of the concept of citizenship in the contemporary social sciences. The second section argues that a comprehensive sociological theory of citizenship needs to account for the importance of four dimensions: the content, the type, the conditions, and the arrangements of citizenship. The third section suggests that in order to understand the sociological significance of T.H. Marshall’s account of legal, political, and social rights we need to explore the particular historical contexts in which citizenship rights became ideologically and institutionally relevant. The fourth section offers some critical reflections on the main shortcomings of the Marshallian approach to citizenship. The fifth section draws an analogy between the transformation of social movements and the transformation of citizenship. The sixth section sheds light on the fact that contemporary citizenship studies are confronted with a curious paradox: the differentiation of citizenship has led to both the relativistic impoverishment and the pluralistic enrichment of contemporary accounts of ‘the social’ and ‘the political’.The paper concludes by arguing that, under conditions of late modernity, the state’s capacity to gain political legitimacy increasingly depends on its ability to confront the normative challenges posed by the ubiquity of societal complexity
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