991 resultados para Inherent chirality
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There is a broad consensus among economists that technologicalchange has been a major contributor to the productivity growth and, hence, to the growth of the material welfare in western industrialized countries at least over the last century. Paradoxically, this issue has not been the focal point of theoretical economics. At the same time, we have witnessed the rise of the importance of technological issues at the strategic management level of business firms. Interestingly, the research has not accurately responded to this challenge either. The tension between the overwhelming empirical evidence of the importance of technology and its relative omission in the research offers a challenging target for a methodological endeavor. This study deals with the question of how different theories cope with technology and explain technological change. The focusis at the firm level and the analysis concentrates on metatheoretical issues, except for the last two chapters, which examine the problems of strategic management of technology. Here the aim is to build a new evolutionary-based theoreticalframework to analyze innovation processes at the firm level. The study consistsof ten chapters. Chapter 1 poses the research problem and contrasts the two basic approaches, neoclassical and evolutionary, to be analyzed. Chapter 2 introduces the methodological framework which is based on the methodology of isolation. Methodological and ontoogical commitments of the rival approaches are revealed and basic questions concerning their ways of theorizing are elaborated. Chapters 3-6 deal with the so-called substantive isolative criteria. The aim is to examine how different approaches cope with such critical issues as inherent uncertainty and complexity of innovative activities (cognitive isolations, chapter 3), theboundedness of rationality of innovating agents (behavioral isolations, chapter4), the multidimensional nature of technology (chapter 5), and governance costsrelated to technology (chapter 6). Chapters 7 and 8 put all these things together and look at the explanatory structures used by the neoclassical and evolutionary approaches in the light of substantive isolations. The last two cpahters of the study utilize the methodological framework and tools to appraise different economics-based candidates in the context of strategic management of technology. The aim is to analyze how different approaches answer the fundamental question: How can firms gain competitive advantages through innovations and how can the rents appropriated from successful innovations be sustained? The last chapter introduces a new evolutionary-based technology management framework. Also the largely omitted issues of entrepreneurship are examined.
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Control applications of switched mode power supplies have been widely investigated. The main objective ofresearch and development (R&D) in this field is always to find the most suitable control method to be implemented in various DC/DC converter topologies. Inother words, the goal is to select a control method capable of improving the efficiency of the converter, reducing the effect of disturbances (line and load variation), lessening the effect of EMI (electro magnetic interference), and beingless effected by component variation. The main objective of this research work is to study different control methods implemented in switched mode power supplies namely (PID control, hysteresis control, adaptive control, current programmed control, variable structure control (VSC), and sliding mode control (SMC). The advantages and drawbacks of each control method are given. Two control methods, the PID and the SMC are selected and their effects on DC/DC (Buck, Boost, and Buck-Boost) converters are examined. Matlab/SimulinkTM is used to implement PID control method in DC/DC Buck converter and SMC in DC/DC (Buck, and Buck Boost) converters. For the prototype, operational amplifiers (op-amps) are used to implement PID control in DC/DC Buck converter. For SMC op-amps are implemented in DC/DC Buck converter and dSPACETM is used to control the DC/DC Buck-Boost converter. The SMC can be applied to the DC/DC (Buck, Boost, and Buck-Boost) converters. A comparison of the effects of the PID control and the SMC on the DC/DC Buck converter response in steady state, under line variations, load variations, and different component variations is performed. Also the Conducted RF-Emissions between the PID and SMC DC/DC Buck Converter are compared. The thesis shows that, in comparison with the PID control, the SMC provides better steady-state response, better dynamic response, less EMI, inherent order reduction, robustness against system uncertainty disturbances, and an implicit stability proof. Giving a better steady-state and dynamic response, the SMC is implemented in a DC/DC resonant converter. The half-wave zero current switching (HWZCS) DC/DC Buck converter is selected as a converter topology. A general guideline to select the tank component values, needed for the designing of a HWZCS DC/DC Buck, is obtained. The implementation of the SMC to a HWZCS DC/DC Buck converter is analysed. The converter response is investigated in the steady-state region and in the dynamic region.
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1. Introduction "The one that has compiled ... a database, the collection, securing the validity or presentation of which has required an essential investment, has the sole right to control the content over the whole work or over either a qualitatively or quantitatively substantial part of the work both by means of reproduction and by making them available to the public", Finnish Copyright Act, section 49.1 These are the laconic words that implemented the much-awaited and hotly debated European Community Directive on the legal protection of databases,2 the EDD, into Finnish Copyright legislation in 1998. Now in the year 2005, after more than half a decade of the domestic implementation it is yet uncertain as to the proper meaning and construction of the convoluted qualitative criteria the current legislation employs as a prerequisite for the database protection both in Finland and within the European Union. Further, this opaque Pan-European instrument has the potential of bringing about a number of far-reaching economic and cultural ramifications, which have remained largely uncharted or unobserved. Thus the task of understanding this particular and currently peculiarly European new intellectual property regime is twofold: first, to understand the mechanics and functioning of the EDD and second, to realise the potential and risks inherent in the new legislation in economic, cultural and societal dimensions. 2. Subject-matter of the study: basic issues The first part of the task mentioned above is straightforward: questions such as what is meant by the key concepts triggering the functioning of the EDD such as presentation of independent information, what constitutes an essential investment in acquiring data and when the reproduction of a given database reaches either qualitatively or quantitatively the threshold of substantiality before the right-holder of a database can avail himself of the remedies provided by the statutory framework remain unclear and call for a careful analysis. As for second task, it is already obvious that the practical importance of the legal protection providedby the database right is in the rapid increase. The accelerating transformationof information into digital form is an existing fact, not merely a reflection of a shape of things to come in the future. To take a simple example, the digitisation of a map, traditionally in paper format and protected by copyright, can provide the consumer a markedly easier and faster access to the wanted material and the price can be, depending on the current state of the marketplace, cheaper than that of the traditional form or even free by means of public lending libraries providing access to the information online. This also renders it possible for authors and publishers to make available and sell their products to markedly larger, international markets while the production and distribution costs can be kept at minimum due to the new electronic production, marketing and distributionmechanisms to mention a few. The troublesome side is for authors and publishers the vastly enhanced potential for illegal copying by electronic means, producing numerous virtually identical copies at speed. The fear of illegal copying canlead to stark technical protection that in turn can dampen down the demand for information goods and services and furthermore, efficiently hamper the right of access to the materials available lawfully in electronic form and thus weaken the possibility of access to information, education and the cultural heritage of anation or nations, a condition precedent for a functioning democracy. 3. Particular issues in Digital Economy and Information Networks All what is said above applies a fortiori to the databases. As a result of the ubiquity of the Internet and the pending breakthrough of Mobile Internet, peer-to-peer Networks, Localand Wide Local Area Networks, a rapidly increasing amount of information not protected by traditional copyright, such as various lists, catalogues and tables,3previously protected partially by the old section 49 of the Finnish Copyright act are available free or for consideration in the Internet, and by the same token importantly, numerous databases are collected in order to enable the marketing, tendering and selling products and services in above mentioned networks. Databases and the information embedded therein constitutes a pivotal element in virtually any commercial operation including product and service development, scientific research and education. A poignant but not instantaneously an obvious example of this is a database consisting of physical coordinates of a certain selected group of customers for marketing purposes through cellular phones, laptops and several handheld or vehicle-based devices connected online. These practical needs call for answer to a plethora of questions already outlined above: Has thecollection and securing the validity of this information required an essential input? What qualifies as a quantitatively or qualitatively significant investment? According to the Directive, the database comprises works, information and other independent materials, which are arranged in systematic or methodical way andare individually accessible by electronic or other means. Under what circumstances then, are the materials regarded as arranged in systematic or methodical way? Only when the protected elements of a database are established, the question concerning the scope of protection becomes acute. In digital context, the traditional notions of reproduction and making available to the public of digital materials seem to fit ill or lead into interpretations that are at variance with analogous domain as regards the lawful and illegal uses of information. This may well interfere with or rework the way in which the commercial and other operators have to establish themselves and function in the existing value networks of information products and services. 4. International sphere After the expiry of the implementation period for the European Community Directive on legal protection of databases, the goals of the Directive must have been consolidated into the domestic legislations of the current twenty-five Member States within the European Union. On one hand, these fundamental questions readily imply that the problemsrelated to correct construction of the Directive underlying the domestic legislation transpire the national boundaries. On the other hand, the disputes arisingon account of the implementation and interpretation of the Directive on the European level attract significance domestically. Consequently, the guidelines on correct interpretation of the Directive importing the practical, business-oriented solutions may well have application on European level. This underlines the exigency for a thorough analysis on the implications of the meaning and potential scope of Database protection in Finland and the European Union. This position hasto be contrasted with the larger, international sphere, which in early 2005 does differ markedly from European Union stance, directly having a negative effect on international trade particularly in digital content. A particular case in point is the USA, a database producer primus inter pares, not at least yet having aSui Generis database regime or its kin, while both the political and academic discourse on the matter abounds. 5. The objectives of the study The above mentioned background with its several open issues calls for the detailed study of thefollowing questions: -What is a database-at-law and when is a database protected by intellectual property rights, particularly by the European database regime?What is the international situation? -How is a database protected and what is its relation with other intellectual property regimes, particularly in the Digital context? -The opportunities and threats provided by current protection to creators, users and the society as a whole, including the commercial and cultural implications? -The difficult question on relation of the Database protection and protection of factual information as such. 6. Dsiposition The Study, in purporting to analyse and cast light on the questions above, is divided into three mainparts. The first part has the purpose of introducing the political and rationalbackground and subsequent legislative evolution path of the European database protection, reflected against the international backdrop on the issue. An introduction to databases, originally a vehicle of modern computing and information andcommunication technology, is also incorporated. The second part sets out the chosen and existing two-tier model of the database protection, reviewing both itscopyright and Sui Generis right facets in detail together with the emergent application of the machinery in real-life societal and particularly commercial context. Furthermore, a general outline of copyright, relevant in context of copyright databases is provided. For purposes of further comparison, a chapter on the precursor of Sui Generi, database right, the Nordic catalogue rule also ensues. The third and final part analyses the positive and negative impact of the database protection system and attempts to scrutinize the implications further in the future with some caveats and tentative recommendations, in particular as regards the convoluted issue concerning the IPR protection of information per se, a new tenet in the domain of copyright and related rights.
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Invasive species are an excellent opportunity to think about the nature society desires, particularly in the face of global changes. Nature and human views of nature are rapidly evolving; our approach to bio- logical invasions through biosecurity institutions and land management policies must evolve in tandem with these changes. We review three dimensions that are insufficiently addressed. First, biological inva- sions are culturally shaped and interpreted. Humans play a major role in the movement and nurturing of alien life, and esthetics, perception, and emotion are deeply implicated in the management of invasive species. What people fear or regret with invasive species are not their effects on nature per se, but their effects on a particular desired nature, and policymaking must reflect this. Second, biological invasions are not restricted to negative impacts. Invasions take place in landscapes where many natural condi- tions have been altered, so policy tools must recognize that invasive species are a functional, structural, and compositional part of transformed ecosystems. In some cases, native species benefit from changes in resource availability caused by invasions or from protections provided by an invasive plant. Finally, invasive species can help ecosystems and people to adapt to global change by maintaining ecosystem processes such as productivity, carbon storage, and nutrient cycling in a context of climate change or land cover transformations. While recognition is growing among ecologists that novel, invaded ecosystems have value, and while the on-the-ground application of biosecurity policies has of necessity adjusted to local contexts and other agendas, invasion biology could aid policymaking by better addressing the three complexities inherent in the three dimensions highlighted above.
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The advent of new advances in mobile computing has changed the manner we do our daily work, even enabling us to perform collaborative activities. However, current groupware approaches do not offer an integrating and efficient solution that jointly tackles the flexibility and heterogeneity inherent to mobility as well as the awareness aspects intrinsic to collaborative environments. Issues related to the diversity of contexts of use are collected under the term plasticity. A great amount of tools have emerged offering a solution to some of these issues, although always focused on individual scenarios. We are working on reusing and specializing some already existing plasticity tools to the groupware design. The aim is to offer the benefits from plasticity and awareness jointly, trying to reach a real collaboration and a deeper understanding of multi-environment groupware scenarios. In particular, this paper presents a conceptual framework aimed at being a reference for the generation of plastic User Interfaces for collaborative environments in a systematic and comprehensive way. Starting from a previous conceptual framework for individual environments, inspired on the model-based approach, we introduce specific components and considerations related to groupware.
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El proceso de repoblación forestal es bastante complejo, ya que implica numerosos factores, cada uno de los cuales debe ser comprendido de forma individual, y conocidas sus relaciones con otros factores con los cuales interactúa. La forma de evaluar de manera integral el resultado de estos factores es mediante el control de calidad. La respuesta de la planta en una estación particular va a depender de la capacidad de respuesta a unas condiciones ambientales limitantes, y de la forma en como esas condiciones limitan su supervivencia y crecimiento, o bien pueden ser modificadas para mejorar su arraigo. Las actividades culturales propias de las repoblaciones (ej. proceimiento de preparación, control de la vegetación, cuidados culturales, etc.) van a influir de manera directa en el éxito de la misma. La adecuada ejecución y el control de las mismas van a permitir mejorar el éxito de las repoblaciones, pero también ayudan a identificar las causas de las perdidas producidas y, por tanto, corregir defectos que condicionan su éxito final.
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Signal transduction systems mediate the response and adaptation of organisms to environmental changes. In prokaryotes, this signal transduction is often done through Two Component Systems (TCS). These TCS are phosphotransfer protein cascades, and in their prototypical form they are composed by a kinase that senses the environmental signals (SK) and by a response regulator (RR) that regulates the cellular response. This basic motif can be modified by the addition of a third protein that interacts either with the SK or the RR in a way that could change the dynamic response of the TCS module. In this work we aim at understanding the effect of such an additional protein (which we call ‘‘third component’’) on the functional properties of a prototypical TCS. To do so we build mathematical models of TCS with alternative designs for their interaction with that third component. These mathematical models are analyzed in order to identify the differences in dynamic behavior inherent to each design, with respect to functionally relevant properties such as sensitivity to changes in either the parameter values or the molecular concentrations, temporal responsiveness, possibility of multiple steady states, or stochastic fluctuations in the system. The differences are then correlated to the physiological requirements that impinge on the functioning of the TCS. This analysis sheds light on both, the dynamic behavior of synthetically designed TCS, and the conditions under which natural selection might favor each of the designs. We find that a third component that modulates SK activity increases the parameter space where a bistable response of the TCS module to signals is possible, if SK is monofunctional, but decreases it when the SK is bifunctional. The presence of a third component that modulates RR activity decreases the parameter space where a bistable response of the TCS module to signals is possible.
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Native plants and animals are a natural heritage threatened by one of the six greatest extinction events in Earth's history. Humans, through habitat transformation, exploitation, and species introductions, are driving this extinction event. To turn this tide, Speziale et al. (2014) suggest reducing human dependence on non-native species by increasing the use, harvest, planting, and raising of native species, thereby increasing their cultural and economic value. The search for new or under-appreciated uses of native species is laudable, especially if it helps protect them and contributes to local cultural diversity. Such efforts are arguably an inherent trait of human curiosity and entrepreneurship and are a central platform of popular movements such as slow foods and native gardening. However, Speziale et al.'s hypothesis - that using native species can protect them - is less simple than they suggest. We refute the idea of nativism that underpins Speziale et al.'s proposal and makes it poorly defensible and considered the unaddressed consequences of the proposal for people and for conservation.
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BACKGROUND: Pain assessment in mechanically ventilated patients is challenging, because nurses need to decode pain behaviour, interpret pain scores, and make appropriate decisions. This clinical reasoning process is inherent to advanced nursing practice, but is poorly understood. A better understanding of this process could contribute to improved pain assessment and management. OBJECTIVE: This study aimed to describe the indicators that influence expert nurses' clinical reasoning when assessing pain in critically ill nonverbal patients. METHODS: This descriptive observational study was conducted in the adult intensive care unit (ICU) of a tertiary referral hospital in Western Switzerland. A purposive sample of expert nurses, caring for nonverbal ventilated patients who received sedation and analgesia, were invited to participate in the study. Data were collected in "real life" using recorded think-aloud combined with direct non-participant observation and brief interviews. Data were analysed using deductive and inductive content analyses using a theoretical framework related to clinical reasoning and pain. RESULTS: Seven expert nurses with an average of 7.85 (±3.1) years of critical care experience participated in the study. The patients had respiratory distress (n=2), cardiac arrest (n=2), sub-arachnoid bleeding (n=1), and multi-trauma (n=2). A total of 1344 quotes in five categories were identified. Patients' physiological stability was the principal indicator for making decision in relation to pain management. Results also showed that it is a permanent challenge for nurses to discriminate situations requiring sedation from situations requiring analgesia. Expert nurses mainly used working knowledge and patterns to anticipate and prevent pain. CONCLUSIONS: Patient's clinical condition is important for making decision about pain in critically ill nonverbal patients. The concept of pain cannot be assessed in isolation and its assessment should take the patient's clinical stability and sedation into account. Further research is warranted to confirm these results.
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Els autors reflexionen sobre la representativitat dels dialectalismes inclosos en algunes obres lexicogràfiques catalanes, atenent als problemes que es deriven de la selecció lèxica pròpiament dita i de l'abast semàntic d'aquestes unitats. S'hi afegeixen, alhora, aspectes inherents al component lèxic, com ara la variació interna o externa a què està sotmès. Els exemples adduïts provenen en gran part de la recerca duta a terme per a l'elaboració del Diccionari de la pronúncia del català nord-occidental (lleidatà).
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In spite of recent advances in describing the health outcomes of exposure to nanoparticles (NPs), it still remains unclear how exactly NPs interact with their cellular targets. Size, surface, mass, geometry, and composition may all play a beneficial role as well as causing toxicity. Concerns of scientists, politicians and the public about potential health hazards associated with NPs need to be answered. With the variety of exposure routes available, there is potential for NPs to reach every organ in the body but we know little about the impact this might have. The main objective of the FP7 NanoTEST project ( www.nanotest-fp7.eu ) was a better understanding of mechanisms of interactions of NPs employed in nanomedicine with cells, tissues and organs and to address critical issues relating to toxicity testing especially with respect to alternatives to tests on animals. Here we describe an approach towards alternative testing strategies for hazard and risk assessment of nanomaterials, highlighting the adaptation of standard methods demanded by the special physicochemical features of nanomaterials and bioavailability studies. The work has assessed a broad range of toxicity tests, cell models and NP types and concentrations taking into account the inherent impact of NP properties and the effects of changes in experimental conditions using well-characterized NPs. The results of the studies have been used to generate recommendations for a suitable and robust testing strategy which can be applied to new medical NPs as they are developed.
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Psychophysical studies suggest that humans preferentially use a narrow band of low spatial frequencies for face recognition. Here we asked whether artificial face recognition systems have an improved recognition performance at the same spatial frequencies as humans. To this end, we estimated recognition performance over a large database of face images by computing three discriminability measures: Fisher Linear Discriminant Analysis, Non-Parametric Discriminant Analysis, and Mutual Information. In order to address frequency dependence, discriminabilities were measured as a function of (filtered) image size. All three measures revealed a maximum at the same image sizes, where the spatial frequency content corresponds to the psychophysical found frequencies. Our results therefore support the notion that the critical band of spatial frequencies for face recognition in humans and machines follows from inherent properties of face images, and that the use of these frequencies is associated with optimal face recognition performance.
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Conflicts are inherent to the human condition, as they are for all living beings. Disputes about resources or access to mating partners are among the most common causes of conflict. Conflict is herein defined as a struggle or contest between individuals or parties, and may involve a variety of aggressive behaviours. In humans, aggressiveness, violence and conflicts, including individual predisposal to conflict resolution, have traditionally been said to have deep cultural roots, but recent research in both neuroscience and genetics has shown the influence of genes on such complex behavioural traits. In this paper, recent data on the genetic aspects of these interrelated behaviours will be put together, including the effects of particular genes, the influence of stress and gender on gene regulation, and gene-environment interactions, all of which may influence biological predisposal to conflict resolution. Other genetically influenced behavioural aspects involved in conflicts and conflict resolution, such as sociability, will also be discussed. The importance of taking into account genetic and biological data to provide strategies for conflict resolution will be highlighted.
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Electrical impedance tomography (EIT) allows the measurement of intra-thoracic impedance changes related to cardiovascular activity. As a safe and low-cost imaging modality, EIT is an appealing candidate for non-invasive and continuous haemodynamic monitoring. EIT has recently been shown to allow the assessment of aortic blood pressure via the estimation of the aortic pulse arrival time (PAT). However, finding the aortic signal within EIT image sequences is a challenging task: the signal has a small amplitude and is difficult to locate due to the small size of the aorta and the inherent low spatial resolution of EIT. In order to most reliably detect the aortic signal, our objective was to understand the effect of EIT measurement settings (electrode belt placement, reconstruction algorithm). This paper investigates the influence of three transversal belt placements and two commonly-used difference reconstruction algorithms (Gauss-Newton and GREIT) on the measurement of aortic signals in view of aortic blood pressure estimation via EIT. A magnetic resonance imaging based three-dimensional finite element model of the haemodynamic bio-impedance properties of the human thorax was created. Two simulation experiments were performed with the aim to (1) evaluate the timing error in aortic PAT estimation and (2) quantify the strength of the aortic signal in each pixel of the EIT image sequences. Both experiments reveal better performance for images reconstructed with Gauss-Newton (with a noise figure of 0.5 or above) and a belt placement at the height of the heart or higher. According to the noise-free scenarios simulated, the uncertainty in the analysis of the aortic EIT signal is expected to induce blood pressure errors of at least ± 1.4 mmHg.
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Guava response to liming and fertilization can be monitored by tissue testing. Tissue nutrient signature is often diagnosed against nutrient concentration standards. However, this approach has been criticized for not considering nutrient interactions and to generate numerical biases as a result of data redundancy, scale dependency and non-normal distribution. Techniques of compositional data analysis can control those biases by balancing groups of nutrients, such as those involved in liming and fertilization. The sequentially arranged and orthonormal isometric log ratios (ilr) or balances avoid numerical bias inherent to compositional data. The objectives were to relate tissue nutrient balances with the production of "Paluma" guava orchards differentially limed and fertilized, and to adjust the current patterns of nutrient balance with the range of more productive guava trees. It was conducted one experiment of 7-yr of liming and three experiments of 3-yr with N, P and K trials in 'Paluma' orchards on an Oxisol. Plant N, P, K, Ca and Mg were monitored yearly. It was selected the [N, P, K | Ca, Mg], [N, P | K], [N | P] and [Ca | Mg] balances to set apart the effects of liming (Ca-Mg) and fertilizers (N-K) on macronutrient balances. Liming largely influenced nutrient balances of guava in the Oxisol while fertilization was less influential. The large range of guava yields and nutrient balances allowed defining balance ranges and comparing them with the critical ranges of nutrient concentration values currently used in Brazil and combined into ilr coordinates.