76 resultados para History of Political Ideas
Resumo:
Principal Topic : According to Shane & Venkataraman (2000) entrepreneurship consists of the recognition and exploitation of venture ideas - or opportunities as they often called - to create future goods and services. This definition puts venture ideas is at the heart of entrepreneurship research. Substantial research has been done on venture ideas in order to enhance our understanding of this phenomenon (e.g. Choi & Shepherd, 2004; Shane, 2000; Shepherd & DeTienne, 2005). However, we are yet to learn what factors drive entrepreneurs' perceptions of the relative attractiveness of venture ideas, and how important different idea characteristics are for such assessments. Ruef (2002) recognized that there is an uneven distribution of venture ideas undertaken by entrepreneurs in the USA. A majority introduce either a new product/service or access a new market or market segment. A smaller percentage of entrepreneurs introduce a new method of production, organizing, or distribution. This implies that some forms of venture ideas are perceived by entrepreneurs as more important or valuable than others. However, Ruef does not provide any information regarding why some forms of venture ideas are more common than others among entrepreneurs. Therefore, this study empirically investigates what factors affect the attractiveness of venture ideas as well as their relative importance. Based on two key characteristics of venture ideas, namely venture idea newness and relatedness, our study investigates how different types and degrees of newness and relatedness of venture ideas affect their attractiveness as perceived by expert entrepreneurs. Methodology/Key : Propositions According to Schumpeter (1934) entrepreneurs introduce different types of venture ideas such as new products/services, new method of production, enter into new markets/customer and new method of promotion. Further, according to Schumpeter (1934) and Kirzner (1973) venture ideas introduced to the market range along a continuum of innovative to imitative ideas. The distinction between these two extremes of venture idea highlights an important property of venture idea, namely their newness. Entrepreneurs, in order to gain competitive advantage or above average returns introduce their venture ideas which may be either new to the world, new to the market that they seek to enter, substantially improved from current offerings and an imitative form of existing offerings. Expert entrepreneurs may be more attracted to venture ideas that exhibit high degree of newness because of the higher newness is coupled with increased market potential (Drucker, 1985) Moreover, certain individual characteristics also affect the attractiveness of venture idea. According to Shane (2000), individual's prior knowledge is closely associated with the recognition of venture ideas. Sarasvathy's (2001) Effectuation theory proposes a high degree of relatedness between venture ideas and the resource position of the individual. Thus, entrepreneurs may be more attracted to venture ideas that are closely aligned with the knowledge and/or resources they already possess. On the other hand, the potential financial gain (Shepherd & DeTienne, 2005) may be larger for ideas that are not close to the entrepreneurs' home turf. Therefore, potential financial gain is a stimulus that has to be considered separately. We aim to examine how entrepreneurs weigh considerations of different forms of newness and relatedness as well as potential financial gain in assessing the attractiveness of venture ideas. We use conjoint analysis to determine how expert entrepreneurs develop preferences for venture ideas which involved with different degrees of newness, relatedness and potential gain. This analytical method paves way to measure the trade-offs they make when choosing a particular venture idea. The conjoint analysis estimates respondents' preferences in terms of utilities (or part-worth) for each level of newness, relatedness and potential gain of venture ideas. A sample of 50 expert entrepreneurs who were awarded young entrepreneurship awards in Sri Lanka in 2007 is used for interviews. Each respondent is interviewed providing with 32 scenarios which explicate different combinations of possible profiles open them into consideration. Conjoint software (SPSS) is used to analyse data. Results and Implications : The data collection of this study is still underway. However, results of this study will provide information regarding the attractiveness of each level of newness, relatedness and potential gain of venture idea and their relative importance in a business model. Additionally, these results provide important implications for entrepreneurs, consultants and other stakeholders as regards the importance of different of attributes of venture idea coupled with different levels. Entrepreneurs, consultants and other stakeholders could make decisions accordingly.
Resumo:
The urban waterfront may be regarded as the littoral frontier of human settlement. Typically, over the years, it advances, sometimes retreats, where terrestrial and aquatic processes interact and frequently contest this margin of occupation. Because most towns and cities are sited beside water bodies, many of these urban centers on or close to the sea, their physical expansion is constrained by the existence of aquatic areas in one or more directions from the core. It is usually much easier for new urban development to occur along or inland from the waterfront. Where other physical constraints, such as rugged hills or mountains, make expansion difficult or expensive, building at greater densities or construction on steep slopes is a common response. This kind of development, though technically feasible, is usually more expensive than construction on level or gently sloping land, however. Moreover, there are many reasons for developing along the shore or riverfront in preference to using sites further inland. The high cost of developing existing dry land that presents serious construction difficulties is one reason for creating new land from adjacent areas that are permanently or periodically under water. Another reason is the relatively high value of artificially created land close to the urban centre when compared with the value of existing developable space at a greater distance inland. The creation of space for development is not the only motivation for urban expansion into aquatic areas. Commonly, urban places on the margins of the sea, estuaries, rivers or great lakes are, or were once, ports where shipping played an important role in the economy. The demand for deep waterfronts to allow ships to berth and for adjacent space to accommodate various port facilities has encouraged the advance of the urban land area across marginal shallows in ports around the world. The space and locational demands of port related industry and commerce, too, have contributed to this process. Often closely related to these developments is the generation of waste, including domestic refuse, unwanted industrial by-products, site formation and demolition debris and harbor dredgings. From ancient times, the foreshore has been used as a disposal area for waste from nearby settlements, a practice that continues on a huge scale today. Land formed in this way has long been used for urban development, despite problems that can arise from the nature of the dumped material and the way in which it is deposited. Disposal of waste material is a major factor in the creation of new urban land. Pollution of the foreshore and other water margin wetlands in this way encouraged the idea that the reclamation of these areas may be desirable on public health grounds. With reference to examples from various parts of the world, the historical development of the urban littoral frontier and its effects on the morphology and character of towns and cities are illustrated and discussed. The threat of rising sea levels and the heritage value of many waterfront areas are other considerations that are addressed.
Resumo:
The individual-opportunity nexus emphasizes that both the characteristics of individuals and venture ideas have roles in the entrepreneurial process (Shane & Venkataraman, 2000). Following upon this assertion the present study examined whether the venture idea novelty and investment of resources can make an important part in the venture creation process. Data analysed for a sample of nascent entrepreneurs in Australia suggests that the novelty of venture ideas restricts the performance of nascent ventures. However, the more investment of time and money do not show a significant impact to the venture performance.
Resumo:
Molluscan larval ontogeny is a highly conserved process comprising three principal developmental stages. A characteristic unique to each of these stages is shell design, termed prodissoconch I, prodissoconch II and dissoconch. These shells vary in morphology, mineralogy and microstructure. The discrete temporal transitions in shell biomineralization between these larval stages are utilized in this study to investigate transcriptional involvement in several distinct biomineralization events. Scanning electron microscopy and X-ray diffraction analysis of P. maxima larvae and juveniles collected throughout post-embryonic ontogenesis, document the mineralogy and microstructure of each shelled stage as well as establishing a timeline for transitions in biomineralization. P. maxima larval samples most representative of these biomineralization distinctions and transitions were analyzed for differential gene expression on the microarray platform PmaxArray 1.0. A number of transcripts are reported as differentially expressed in correlation to the mineralization events of P. maxima larval ontogeny. Some of those isolated are known shell matrix genes while others are novel; these are discussed in relation to potential shell formation roles. This interdisciplinary investigation has linked the shell developments of P. maxima larval ontogeny with corresponding gene expression profiles, furthering the elucidation of shell biomineralization.
Resumo:
Haematopoiesis is the process by which a hierarchy of mature and progenitor blood cells are formed. These cell populations are all derived from multipotent haematopoietic stem cells (HSC), which reside in the bone marrow ‘niche’ of adult humans. Over the lifetime of a healthy individual, this HSC population replenishes between 1010-1011 blood cells on a daily basis. Dysregulation of this system can lead to a number of haematopoietic diseases, including aplastic anaemias and leukaemias, which result in, or require for disease resolution, bone marrow cell depletion. In 1956, E. Donnall Thomas demonstrated that haematopoiesis could be restored by transplanting bone marrow-derived cells from one man into his identical twin brother, who was suffering from advanced leukaemia. His success drew significant interest in academic research and medicine communities, and 12 years later, the first successful allogeneic transplant was performed. To this day, HSCs remain the most studied and characterised stem cell population. In fact, HSCs are the only stem cell population routinely utilised in the clinic. As such, HSCs function as a model system both for the biological investigation of stem cells, as well as for their clinical application. Herein, we briefly review HSC transplantation, strategies for the ex vivo cultivation of HSCs, recent clinical outcomes, and their impact on the future direction of HSC transplantation therapy.
Resumo:
The ratite moa (Aves: Dinornithiformes) were a speciose group of massive graviportal avian herbivores that dominated the New Zealand (NZ) ecosystem until their extinction �600 years ago. The phylogeny and evolutionary history of this morphologically diverse order has remained controversial since their initial description in 1839. We synthesize mitochondrial phylogenetic information from 263 subfossil moa specimens from across NZ with morphological, ecological, and new geological data to create the first comprehensive phylogeny, taxonomy, and evolutionary timeframe for all of the species of an extinct order. We also present an important new geological/paleogeographical model of late Cenozoic NZ, which suggests that terrestrial biota on the North and South Island landmasses were isolated for most of the past 20–30 Ma. The data reveal that the patterns of genetic diversity within and between differentmoaclades reflect a complex history following a major marine transgression in the Oligocene, affected by marine barriers, tectonic activity, and glacial cycles. Surprisingly, the remarkable morphological radiation of moa appears to have occurred much more recently than previous early Miocene (ca. 15 Ma) estimates, and was coincident with the accelerated uplift of the Southern Alps just ca. 5–8.5 Ma. Together with recent fossil evidence, these data suggest that the recent evolutionary history of nearly all of the iconic NZ terrestrial biota occurred principally on just the South Island.
Resumo:
Cockatoos are the distinctive family Cacatuidae, a major lineage of the order of parrots (Psittaciformes) and distributed throughout the Australasian region of the world. However, the evolutionary history of cockatoos is not well understood. We investigated the phylogeny of cockatoos based on three mitochondrial and three nuclear DNA genes obtained from 16 of 21 species of Cacatuidae. In addition, five novel mitochondrial genomes were used to estimate time of divergence and our estimates indicate Cacatuidae diverged from Psittacidae approximately 40.7 million years ago (95% CI 51.6–30.3 Ma) during the Eocene. Our data shows Cacatuidae began to diversify approximately 27.9 Ma (95% CI 38.1–18.3 Ma) during the Oligocene. The early to middle Miocene (20–10 Ma) was a significant period in the evolution of modern Australian environments and vegetation, in which a transformation from mainly mesic to xeric habitats (e.g., fire-adapted sclerophyll vegetation and grasslands) occurred. We hypothesize that this environmental transformation was a driving force behind the diversification of cockatoos. A detailed multi-locus molecular phylogeny enabled us to resolve the phylogenetic placements of the Palm Cockatoo (Probosciger aterrimus), Galah (Eolophus roseicapillus), Gang-gang Cockatoo (Callocephalon fimbriatum) and Cockatiel (Nymphicus hollandicus), which have historically been difficult to place within Cacatuidae. When the molecular evidence is analysed in concert with morphology, it is clear that many of the cockatoo species’ diagnostic phenotypic traits such as plumage colour, body size, wing shape and bill morphology have evolved in parallel or convergently across lineages.
Resumo:
This paper focuses on the turning point experiences that worked to transform the researcher during a preliminary consultation process to seek permission to conduct of a small pilot project on one Torres Strait Island. The project aimed to learn from parents how they support their children in their mathematics learning. Drawing on a community research design, a consultative meeting was held with one Torres Strait Islander community to discuss the possibility of piloting a small project that focused on working with parents and children to learn about early mathematics processes. Preliminary data indicated that parents use networks in their community. It highlighted the funds of knowledge of mathematics that exist in the community and which are used to teach their children. Such knowledges are situated within a community’s unique histories, culture and the voices of the people. “Omei” tree means the Tree of Wisdom in the Island community.