908 resultados para put and call option


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We recently have introduced the term vasculogenic mimicry to describe the unique ability of aggressive melanoma tumor cells to form tubular structures and patterned networks in three-dimensional culture, which “mimics” embryonic vasculogenic networks formed by differentiating endothelial cells. In the current study, we address the biological significance of several endothelial-associated molecules (revealed by microarray analysis) with respect to expression and function in highly aggressive and poorly aggressive human cutaneous melanoma cell lines (established from the same patient). In a comparative analysis, CD31 was not expressed by any of the melanoma cell lines, whereas TIE-1 (tyrosine kinase with Ig and epidermal growth factor homology domains-1) was strongly expressed in the highly aggressive tumor cells with a low level of expression in one of the poorly aggressive cell lines. Vascular endothelial (VE)-cadherin was exclusively expressed by highly aggressive melanoma cells and was undetectable in the poorly aggressive tumor cells, suggesting the possibility of a vasculogenic switch. Down-regulation of VE-cadherin expression in the aggressive melanoma cells abrogated their ability to form vasculogenic networks and directly tested the hypothesis that VE-cadherin is critical in melanoma vasculogenic mimicry. These results highlight the plasticity of aggressive melanoma cells and call into question their possible genetic reversion to an embryonic phenotype. This finding could pose a significant clinical challenge in targeting tumor cells that may masquerade as circulating endothelial cells or other embryonic-like stem cells.

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The Mount Antero/White area is a popular prospecting area. Recent expansions in the recreation economy is drawing more visitors to the area. Consequently, visitors may be placing unsustainable pressures on the landscape. In order to help rectify this, the legal, ecological, geologic, aesthetic, recreational, historic, social, and economic character of the Antero/White area has been identified. Four feasible management alternatives have also been recognized. They are a) take no new management actions, b) prohibit motorized activities in the area, c) develop a mineralogical park, and d) a combination of options b and c. Option C has been defended, as it best balances the desires of area users with the underlying ecological and geological character of the area.

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We compared the costs incurred by families attending outpatient appointments at the Royal Children's Hospital (RCH) in Brisbane with those incurred by families who had a consultation via videoconference in their regional area. In each category 200 families were interviewed. The median time spent travelling for videoconferences was 30 min compared with 80 min for face-to-face appointments. Families interviewed in the outpatient department had travelled a median distance of 70 km, while those who had a videoconference at the local hospital had travelled only 20 km. It cost these families much more to attend an appointment at the RCH than to attend a videoconference. Ninety-six per cent of families (193) reported at least one of the following types of expense: 150 families had expenses related to parking (median A$10), 156 had fuel expenses (median A$10) and 122 reported costs related to meals purchased at the RCH (median A$10). Only 21 families who had their appointment via local videoconference reported any additional costs. Specialist appointments via videoconference were a more convenient and cheaper option for families living in regional areas of Queensland than the conventional method of attending outpatient appointments at the specialist hospital in Brisbane.

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Thesis (Ph.D.)--University of Washington, 2016-06

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Despite a considerable surge in herpetological research in Australia over the last couple of decades the Australian microhylid frogs (Cophixalus and Austrochaperina) remain relatively poorly known. Herein I present the results of extensive fieldwork and molecular, morphological and call analysis with the aim of resolving taxonomy, call variation and distributions, and increasing our understanding of breeding biology. Analysis of 943 base pairs of mitochondrial 16S rRNA and 12S rRNA provides a well supported phylogeny that is largely consistent with current taxonomy. Levels of divergence between species are substantial and significant phylogeographic structuring is evident in C. ornatus, C. neglectus and C. aenigma, sp. nov. The description of C. concinnus was based on a mixed collection of two species from Thornton Peak and a new species is described to resolve this. C. aenigma, sp. nov., is described from high-elevation (>750 m) rainforest across the Carbine, Thornton, Finnigan and Bakers Blue Mountain uplands, north-east Queensland. C. concinnus is redescribed as a highly distinct species restricted to rainforest and boulder fields at the summit of Thornton Peak (>1100 m). Despite protection in Daintree National Park in the Wet Tropics World Heritage Area, predictions of the impact of global warming suggest C. concinnus to be of very high conservation concern ( Critically Endangered, IUCN criteria). The mating call of two species ( C. mcdonaldi and C. exiguus) is described for the first time and high levels of call variation within C. ornatus, C. neglectus, C. hosmeri, C. aenigma and Austrochaperina fryi are presented. Such variation is often attributable to genetically divergent lineages, altitudinal variation and courtship; however, in some instances ( particularly within C. hosmeri) the source or function of highly distinct calls at a site remains obscure. Molecular, morphological and call analyses allow the clarification of species distributions, especially in the northern mountains of the Wet Tropics. Notes are presented on the breeding biology of C. aenigma, C. bombiens, C. concinnus, C. exiguus, C. infacetus, C. mcdonaldi, C. monticola, C. neglectus, C. ornatus and C. saxatilis, which are largely consistent with previous accounts: small terrestrial clutches usually attended by a male. Courtship behaviour in C. ornatus is described and the first records of multiple clutching in Australian microhylids are presented (for C. ornatus and C. infacetus).

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Understanding the relationships among testing environments is essential for better targeting cultivars to production environments. To identify patterns of cultivar, environment, cultivar-by-environment interactions, and opportunities for indirect selection for grain yield, a set of 25 spring wheat cultivars from China and the International Maize and Wheat Improvement Center (CIMMYT) was evaluated in nine environments in China and four management environments at CIMMYT in Cd. Obregon, Mexico, during two wheat seasons. Genetic background and original environment were the main factors influencing grain yield performance of the cultivars. Baviacora M 92, Xinchun 2 and Xinchun 6 showed relatively more stable and higher grain yields, whereas highly photoperiod sensitive cultivars Xinkehan 9, Kefeng 6 and Longmai 19 proved consistently inferior across environments, except in Harbin and Keshan, the two high latitude environments. Longmai 26, also from high latitude environments in the northeastern Heilongjiang province, was however probably not as photoperiodicly sensitive as other cultivars; from that region, and produced much higher grain yield and expressed a broader adaptation. None of the environments reported major diseases. Pattern analyses revealed that photoperiod response and planting option on beds were the two main factors underlying the observed interactions for grain yield. The production environment of planting on the flat in Mexico grouped together with Huhhot and Urumqi in both wheat seasons, indicating an indirect response to selection for grain yield in this CIMMYT managed environment could benefit the two Chinese environments. Both the environment of planting on the flat with Chinese Hejin and Yongning, and the three CIMMYT enviromnents planting on raised beds with Chinese Yongning grouped together only in one season, showing that repeatability may not be stable in this case.

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Based on data from 2091 call centre representatives working in 85 call centres in the UK, central assumptions of affective events theory (AET) are tested. AET predicts that specific features of work (e.g. autonomy) have an impact on the arousal of emotions and moods at work that, in turn, co-determine job satisfaction of employees. AET further proposes that job satisfaction is an evaluative judgement that mainly explains cognitive-based behaviour, whereas emotions and moods better predict affective-based behaviour. The results support these assumptions. A clear separation of key constructs (job satisfaction, positive and negative emotions) was possible. Moreover, correlations between several work features (e.g. supervisory support) and job satisfaction were, in part, mediated by work emotions, even when controlling for gender, age, call centre type (in-house versus outsourced centres) and call centre size. Predictions regarding consequences of satisfaction and affect were partly corroborated as continuance commitment was more strongly related to job satisfaction than to positive emotions. In addition, affective commitment and health complaints were related to both emotions and job satisfaction to the same extent. Thus, AET is a fruitful framework for explaining why and how specific management strategies used for designing work features influence important organizational attitudes and well-being of employees. © 2006 British Academy of Management.

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The last decade or so has witnessed the emergence of the national innovation system (NIS) phenomenon. Since then, many scholars have investigated NIS and its implementation in different countries. However, there are very few investigations into the relationship between the NIS of a country and its national innovation capacity. This paper aims to make a contribution in this area by examining the link that currently exists between these two topics. Whilst examining this relationship, we also explore internationalisation and technology transfer, being cognate areas that have been investigated during the same period. This follows our assertion that the link between NIS and national innovation capacity is the mechanism of internationalisation and technology transfer. The NIS approach was introduced in the late 1980s (see Freeman, 1987; Dosi et al., 1988) and further elaborated later (see Lundvall, 1992; Nelson, 1993; Edquist, 1997). In essence, a country?s NIS is a historically grown subsystem of the entire national economy consisting of organisations and institutions which play a major role in the innovative activity in the country. In the NIS approach, interactions within organisations as well as the interplay between organisations and institutions are of central importance. The NIS approach has been used to reveal the structure of the innovation processes and the main actors involved in them in industrialised and emerging countries. Although the national focus remains strong, it has been accompanied by studies seeking to analyse the notion of systems of innovation at an international level and at a sub-national scale (Archibugi et al., 1999). Dosi in the edition of Archibugi et al. (1999) argues that the general background of the discussion of national systems is the observation of non-random distributions across countries of: corporate capabilities; organisational forms; strategies; and ultimately revealed performances, in terms of production efficiency and inputs productivities, rates of innovation, rates of adoption/diffusion of innovation themselves, dynamics of market shares on the world markets, growth of income and employment. They also mention that there are several approaches to NIS. Nelson (1993) focuses upon the specificities of national institutions and policies supporting directly or indirectly innovation, diffusion and skills accumulation. Patel and Pavitt (1991) have stressed the links between the national patterns of technological accumulation and the competencies and innovative strategies of a few major national companies. Amable et al (1997) and Soskice (1993) and Zysman (1994) focus on the specifics of national institutions including, for example, the forms of organization, financial and labour markets, training institutions, forms of state intervention in the economy etc. However, the most common reference is by Lundvall (1992) who argues that the focus on the national level is associated with the fact that national economies vary according to their production system and their institutional framework and these differences are in turn strengthened by different historical experiences, language and culture. On the other hand, the national innovation capability consists of abilities to create and carry new technological possibilities through to economic practice. The term covers a wide range of activities from capability to invent to capability to innovate and to capability to improve existing technology beyond the original design parameters (Kim, 1997). The term innovation is often associated by many with technological change at international frontiers. However, technological capability is not the same as innovation capability. Technological capability refers to assimilation, use, adaptation, and change to existing technologies. It also enables the creation of new technologies and development of new products and processes in response to changing economic environments. It denotes operational command over knowledge (Kim, 1997). It is manifested not merely by the knowledge possessed, but, more important, by the uses to which that knowledge can be put and by the proficiency with which it is applied in the activities of investment and production and in the creation of new knowledge (Westphal et al., 1985). Therefore, the analytical framework that is used in this paper is based on the way a country derives from its NIS a national innovation capacity. There are two perspectives that are identified on this way. These are internationalisation and technology transfer. Even though NIS is not directly related to national innovation capacity, to achieve national innovation capacity from NIS, the country should have the ability for technology transfer. Technology transfer is a link between these two phenomena. On the other hand, internationalisation can be either the input or the output of the relationship between NIS and national innovation capability. If a company is investing in a country because of its national innovation capacity, this can be regarded as an input to the relationship between NIS and national innovation capacity. If this company is investigating the national innovation capacity of a country then, for its internationalisation, the national innovation capacity should be important, which in turn means this company is active in innovation and innovation is also an important success factor. The interrelationship between the investment of the company and the NIS of the country (assuming that the country is competent and competitive in technology transfer) will generate and improve that country?s national innovation capacity. This is the output of internationalisation from the relationship between NIS and national innovation capacity. When companies are evaluating whether to internationalise, they investigate certain factors in the countries in which they are considering to invest. The ability to transfer technology is dependent on ability to adopt a new technology and also on the learning derived from this technology. If countries wish to attract innovation related investment they need to show their ability to have a NIS and also the capability to transfer technology. Without the technology transfer capability, the NIS is not functioning. Therefore, companies that internationalise will investigate the factors common to NIS, technology transfer, and their business needs. Through this paper we will demonstrate this link though its mechanisms. Our research will be through extensive literature review and identifying relevant aspects of previous research carried out by the authors. It will investigate certain factors of different countries that are successful in attracting innovation related foreign direct investment. Through these, we will point out the factors that are important for the link and mechanisms of NIS and national innovation capability.

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Purpose: Current conceptualisations of strategic flexibility and its antecedents are theory-driven, which has resulted in a lack of consensus. To summarise this domain the paper aims to develop and present an a priori conceptual model of the antecedents and outcomes of strategic flexibility. Discussion and insights into the conceptual model, and the relationships specified, are made through a novel qualitative empirical approach. The implications for further research and a framework for further theoretical development are presented. Design/methodology/approach: An exploratory qualitative research design is used applying multiple data collection techniques in a branch network of a large regional retailer in the UK. The development of strategic options and the complex relationship to strategic flexibility is investigated. Findings: The number and type of strategic options developed by managers impact on the degree of strategic flexibility and also on the ability of the firm to achieve competitive differentiation. Additionally, the type of strategic option implemented by managers is dependent on the competitive situation faced at a local level. Evidence of managers' limited perception of competition was identified based on their spatial embeddedness. Research limitations/implications: A single, in-depth case study was used. The data gathered is rich and appropriate for the exploratory approach adopted here. However, generalisability of the findings is limited. Practical implications: Strategic flexibility is rooted in the ability of front-line mangers to develop and implement strategic options; this in turn facilitates competitive differentiation. Originality/value: The research presented is unique in this domain on two accounts. First, theory is developed by presenting an a priori conceptual model, and testing through in-depth qualitative data gathering. Second, insights into strategic flexibility are presented through an examination of managerial cognition, resources and strategic option generation using cognitive mapping and laddering technique. © Emerald Group Publishing Limited.

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The purpose of this study was to investigate the ontogeny of auditory learning via operant contingency in Northern bobwhite (Colinus virginianus ) hatchlings and possible interaction between attention, orienting and learning during early development. Chicks received individual 5 min training sessions in which they received a playback of a bobwhite maternal call at a single delay following each vocalization they emitted. Playback was either from a single randomly chosen speaker or switched back and forth semi-randomly between two speakers during training. Chicks were tested 24 hrs later in a simultaneous choice test between the familiar and an unfamiliar maternal call. It was found that day-old chicks showed a significant time-specific decrement in auditory learning when trained with delays in the range of 470–910 ms between their vocalizations and call playback only when training involved two speakers. Two-day-old birds showed an even more sustained disruption of learning than day-old chicks, whereas three-day-old chicks showed a pattern of intermittent interference with their learning when trained at such delays. A similar but less severe decrement in auditory learning was found when chicks were provided with motor training in which playback was contingent upon chicks entering and exiting one of two colored squares placed on the floor of the arena. Chicks provided with playback of the call at randomly chosen delays each time they vocalized exhibited large fluctuations in their responsivity to the auditory stimulus as a function of delay—fluctuations which were correlated significantly with measures of chick learning, particularly at two-days-of-age. When playback was limited to a single location chicks no longer showed a time-specific disruption of their learning of the auditory stimulus. Sequential analyses revealed several patterns suggesting that an attentional process similar or analogous to attentional blink may have contributed both to the observed fluctuations in chick responsivity to the auditory stimulus as a function of delay and to the time-specific learning deficit shown by chicks provided with two-speaker training. The study highlights that learning can be substantially modulated by processes of orienting and attention and has a number of important implications for research within cognitive neuroscience, animal behavior and learning.

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Global connectivity, for anyone, at anyplace, at anytime, to provide high-speed, high-quality, and reliable communication channels for mobile devices, is now becoming a reality. The credit mainly goes to the recent technological advances in wireless communications comprised of a wide range of technologies, services, and applications to fulfill the particular needs of end-users in different deployment scenarios (Wi-Fi, WiMAX, and 3G/4G cellular systems). In such a heterogeneous wireless environment, one of the key ingredients to provide efficient ubiquitous computing with guaranteed quality and continuity of service is the design of intelligent handoff algorithms. Traditional single-metric handoff decision algorithms, such as Received Signal Strength (RSS) based, are not efficient and intelligent enough to minimize the number of unnecessary handoffs, decision delays, and call-dropping and/or blocking probabilities. This research presented a novel approach for the design and implementation of a multi-criteria vertical handoff algorithm for heterogeneous wireless networks. Several parallel Fuzzy Logic Controllers were utilized in combination with different types of ranking algorithms and metric weighting schemes to implement two major modules: the first module estimated the necessity of handoff, and the other module was developed to select the best network as the target of handoff. Simulations based on different traffic classes, utilizing various types of wireless networks were carried out by implementing a wireless test-bed inspired by the concept of Rudimentary Network Emulator (RUNE). Simulation results indicated that the proposed scheme provided better performance in terms of minimizing the unnecessary handoffs, call dropping, and call blocking and handoff blocking probabilities. When subjected to Conversational traffic and compared against the RSS-based reference algorithm, the proposed scheme, utilizing the FTOPSIS ranking algorithm, was able to reduce the average outage probability of MSs moving with high speeds by 17%, new call blocking probability by 22%, the handoff blocking probability by 16%, and the average handoff rate by 40%. The significant reduction in the resulted handoff rate provides MS with efficient power consumption, and more available battery life. These percentages indicated a higher probability of guaranteed session continuity and quality of the currently utilized service, resulting in higher user satisfaction levels.

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This article discusses the challenges of irregular migration for the security of the EU. They are analyzed starting with the European Security Strategy 2003, and the Report on its Implementation, 2008, and notes many failures: The EU Members did not follow the directives adopted in Brussels, the mismanagement of migration and asylum policies, and numerous actions that can be characterized or described as improvised, scattered or irresponsible. The 2016 Global Strategy recognizes these failures and call attention to the European leaders to reconsider how the EU functions and operates, suggesting the need for greater unity and cooperation to achieve a more effective migration policy. However, the article points out that practically all of the sections of the new Strategy dealing with migration were already embodied in previous Strategies, and stress that in parallel with the publication of the 2016 Global Strategy, actions are already undertaken, such as the EU readmission agreements signed with several important third countries of origin.

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This book investigates the complex, sometimes fraught relationship between phenomenology and the natural sciences. The contributors attempt to subvert and complicate the divide that has historically tended to characterize the relationship between the two fields. Phenomenology has traditionally been understood as methodologically distinct from scientific practice, and thus removed from any claim that philosophy is strictly continuous with science. There is some substance to this thinking, which has dominated consideration of the relationship between phenomenology and science throughout the twentieth century. However, there are also emerging trends within both phenomenology and empirical science that complicate this too stark opposition, and call for more systematic consideration of the inter-relation between the two fields. These essays explore such issues, either by directly examining meta-philosophical and methodological matters, or by looking at particular topics that seem to require the resources of each, including imagination, cognition, temporality, affect, imagery, language, and perception.

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Traditional decision making research has often focused on one's ability to choose from a set of prefixed options, ignoring the process by which decision makers generate courses of action (i.e., options) in-situ (Klein, 1993). In complex and dynamic domains, this option generation process is particularly critical to understanding how successful decisions are made (Zsambok & Klein, 1997). When generating response options for oneself to pursue (i.e., during the intervention-phase of decision making) previous research has supported quick and intuitive heuristics, such as the Take-The-First heuristic (TTF; Johnson & Raab, 2003). When generating predictive options for others in the environment (i.e., during the assessment-phase of decision making), previous research has supported the situational-model-building process described by Long Term Working Memory theory (LTWM; see Ward, Ericsson, & Williams, 2013). In the first three experiments, the claims of TTF and LTWM are tested during assessment- and intervention-phase tasks in soccer. To test what other environmental constraints may dictate the use of these cognitive mechanisms, the claims of these models are also tested in the presence and absence of time pressure. In addition to understanding the option generation process, it is important that researchers in complex and dynamic domains also develop tools that can be used by `real-world' professionals. For this reason, three more experiments were conducted to evaluate the effectiveness of a new online assessment of perceptual-cognitive skill in soccer. This test differentiated between skill groups and predicted performance on a previously established test and predicted option generation behavior. The test also outperformed domain-general cognitive tests, but not a domain-specific knowledge test when predicting skill group membership. Implications for theory and training, and future directions for the development of applied tools are discussed.

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It is often argued that managers representing shareholders' interests tend to undertake risky projects because equity resembles a call option on a firm's assets. However, this conclusion is not generally true when bankruptcy risk is explicitly modelled. This paper compares the relative strength of the agency cost and the bankruptcy risk in determining managerial choice of cash-flow volatility in a continuous-time framework. Assume the existing debt has covenants which preclude additional borrowing and that bankruptcy is triggered when the cash balance hits zero, I show that for low levels of debt, shareholders prefer to minimize cash-flow volatility I also work out the critical face value of the debt above which shareholders are risk-seeking rather than risk-avoiding In short, bankruptcy costs being borne by equity mitigates shareholders' desire for risk.