943 resultados para Resource-based View of the Firm


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The enzyme tissue non-specific alkaline phosphatase (TNAP) belongs to the ectophosphatase family. It is present in large amounts in bone in which it plays a role in mineralization but little is known about its function in other tissues. Arguments are accumulating for its involvement in the brain, in particular in view of the neurological symptoms accompanying human TNAP deficiencies. We have previously shown, by histochemistry, alkaline phosphatase (AP) activity in monkey brain vessels and parenchyma in which AP exhibits specific patterns. Here, we clearly attribute this activity to TNAP expression rather than to other APs in primates (human and marmoset) and in rodents (rat and mouse). We have not found any brain-specific transcripts but our data demonstrate that neuronal and endothelial cells exclusively express the bone TNAP transcript in all species tested, except in mouse neurons in which liver TNAP transcripts have also been detected. Moreover, we highlight the developmental regulation of TNAP expression; this also acts during neuronal differentiation. Our study should help to characterize the regulation of the expression of this ectophosphatase in various cell types of the central nervous system.

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In 2009, the Nomenclature Committee on Cell Death (NCCD) proposed a set of recommendations for the definition of distinct cell death morphologies and for the appropriate use of cell death-related terminology, including 'apoptosis', 'necrosis' and 'mitotic catastrophe'. In view of the substantial progress in the biochemical and genetic exploration of cell death, time has come to switch from morphological to molecular definitions of cell death modalities. Here we propose a functional classification of cell death subroutines that applies to both in vitro and in vivo settings and includes extrinsic apoptosis, caspase-dependent or -independent intrinsic apoptosis, regulated necrosis, autophagic cell death and mitotic catastrophe. Moreover, we discuss the utility of expressions indicating additional cell death modalities. On the basis of the new, revised NCCD classification, cell death subroutines are defined by a series of precise, measurable biochemical features.

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During the past 20 years or so, more has become known about the properties of khat, its pharmacology, physiological and psychological effects on humans. However, at the same time its reputation of social and recreational use in traditional contexts has hindered the dissemination of knowledge about its detrimental effects in terms of mortality. This paper focuses on this particular deficit and adds to the knowledge-base by reviewing the scant literature that does exist on mortality associated with the trade and use of khat. We sought all peer-reviewed papers relating to deaths associated with khat. From an initial list of 111, we identified 15 items meeting our selection criteria. Examination of these revealed 61 further relevant items. These were supplemented with published reports, newspaper and other media reports. A conceptual framework was then developed for classifying mortality associated with each stage of the plant's journey from its cultivation, transportation, consumption, to its effects on the human body. The model is demonstrated with concrete examples drawn from the above sources. These highlight a number of issues for which more substantive statistical data are needed, including population-based studies of the physiological and psychological determinants of khat-related fatalities. Khat-consuming communities, and health professionals charged with their care should be more aware of the physiological and psychological effects of khat, together with the risks for morbidity and mortality associated with its use. There is also a need for information to be collected at international and national levels on other causes of death associated with khat cultivation, transportation, and trade. Both these dimensions need to be understood.

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This project intertwines philosophical and historico-literary themes, taking as its starting point the concept of tragic consciousness inherent in the epoch of classicism. The research work makes use of ontological categories in order to describe the underlying principles of the image of the world which was created in philosophical and scientific theories of the 17th century as well as in contemporary drama. Using these categories brought Mr. Vilk to the conclusion that the classical picture of the world implied a certain dualism; not the Manichaean division between light and darkness but the discrimination between nature and absolute being, i.e. God. Mr. Vilk begins with an examination of the philosophical essence of French classical theatre of the XVII and XVIII centuries. The history of French classical tragedy can be divided into three periods: from the mid 17th to early 19th centuries when it triumphed all over France and exerted a powerful influence over almost all European countries; followed by the period of its rejection by the Romantics, who declared classicism to be "artificial and rational"; and finally our own century which has taken a more moderate line. Nevertheless, French classical tragedy has never fully recovered its status. Instead, it is ancient tragedy and the works of Shakespeare that are regarded to be the most adequate embodiment of the tragic. Consequently they still provoke a great number of new interpretations ranging from specialised literary criticism to more philosophical rumination. An important feature of classical tragedy is a system of rules and unities which reveals a hidden ontological structure of the world. The ontological picture of the dramatic world can be described in categories worked out by medieval philosophy - being, essence and existence. The first category is to be understood as a tendency toward permanency and stability (within eternity) connected with this or that fragment of dramatic reality. The second implies a certain set of permanent elements that make up the reality. And the third - existence - should be understood as "an act of being", as a realisation of permanently renewed processes of life. All of these categories can be found in every artistic reality but the accents put on one or another and their interrelations create different ontological perspectives. Mr. Vilk plots the movement of thought, expressed in both philosophical and scientific discourses, away from Aristotle's essential forms, and towards a prioritising of existence, and shows how new forms of literature and drama structured the world according to these evolving requirements. At the same time the world created in classical tragedy fully preserves another ontological paradigm - being - as a fundamental permanence. As far as the tragic hero's motivations are concerned this paradigm is revealed in the dedication of his whole self to some cause, and his oath of fidelity, attitudes which shape his behaviour. It may be the idea of the State, or personal honour, or something borrowed from the emotional sphere, passionate love. Mr. Vilk views the conflicting ambivalence of existence and being, duty as responsibility and duty as fidelity, as underlying the main conflict of classical tragedy of the 17th century. Having plotted the movement of the being/existence duality through its manifestations in 17th century tragedy, Mr. Vilk moves to the 18th century, when tragedy took a philosophical turn. A dualistic view of the world became supplanted by the Enlightenment idea of a natural law, rooted in nature. The main point of tragedy now was to reveal that such conflicts as might take place had an anti-rational nature, that they arose as the result of a kind of superstition caused by social reasons. These themes Mr. Vilk now pursues through Russian dramatists of the 18th and early 19th centuries. He begins with Sumarakov, whose philosophical thought has a religious bias. According to Sumarakov, the dualism of the divineness and naturalness of man is on the one hand an eternal paradox, and on the other, a moral challenge for humans to try to unite the two opposites. His early tragedies are not concerned with social evils or the triumph of natural feelings and human reason, but rather the tragic disharmony in the nature of man and the world. Mr Vilk turns next to the work of Kniazhnin. He is particularly keen to rescue his reputation from the judgements of critics who accuse him of being imitative, and in order to do so, analyses in detail the tragedy "Dido", in which Kniazhnin makes an attempt to revive the image of great heroes and city-founders. Aeneas represents the idea of the "being" of Troy, his destiny is the re-establishment of the city (the future Rome). The moral aspect behind this idea is faithfulness, he devotes himself to Gods. Dido is also the creator of a city, endowed with "natural powers" and abilities, but her creation is lacking internal stability grounded in "being". The unity of the two motives is only achieved through Dido's sacrifice of herself and her city to Aeneus. Mr Vilk's next subject is Kheraskov, whose peculiarity lies in the influence of free-mason mysticism on his work. This section deals with one of the most important philosophical assumptions contained in contemporary free-mason literature of the time - the idea of the trinitarian hierarchy inherent in man and the world: body - soul - spirit, and nature - law - grace. Finally, Mr. Vilk assess the work of Ozerov, the last major Russian tragedian. The tragedies which earned him fame, "Oedipus in Athens", "Fingal" and "Dmitri Donskoi", present a compromise between the Enlightenment's emphasis on harmony and ontological tragic conflict. But it is in "Polixene" that a real meeting of the Russian tradition with the age-old history of the genre takes place. The male and female characters of "Polixene" distinctly express the elements of "being" and "existence". Each of the participants of the conflict possesses some dominant characteristic personifying a certain indispensable part of the moral world, a certain "virtue". But their independent efforts are unable to overcome the ontological gap separating them. The end of the tragedy - Polixene's sacrificial self-immolation - paradoxically combines the glorification of each party involved in the conflict, and their condemnation. The final part of Mr. Vilk's research deals with the influence of "Polixene" upon subsequent dramatic art. In this respect Katenin's "Andromacha", inspired by "Polixene", is important to mention. In "Andromacha" a decisive divergence from the principles of the philosophical tragedy of Russian classicism and the ontology of classicism occurs: a new character appears as an independent personality, directed by his private interest. It was Katenin who was to become the intermediary between Pushkin and classical tragedy.

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The effectiveness of specialised nursing in breast cancer has received limited attention. This systematic literature review aims at (i) presenting and discussing role models of specialised nursing in the area of breast cancer and (ii) suggesting avenues for future research in this field. The ten studies included in the review differ with respect to the roles of specialised nurses as well as the measured outcome variables; thus, the comparability and generalisability of results are limited. Nevertheless, the review indicates that specialised nursing in breast cancer may contribute to improved physical and psycho-social well-being. In view of the limited comparability, the authors call for (i) a more uniform definition of models of specialised nursing in breast cancer care, as well as (ii) rigorous confirmatory studies to evaluate their effectiveness. These two aspects are pivotal in providing a reliable basis for future health care strategies.

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Thrombotic thrombocytopenic purpura (TTP) is a rare disease which responds well to plasma exchange treatment in the majority of patients. We report on a patient with acute TTP caused by severe autoantibody-mediated ADAMTS-13 deficiency, in whom remission was not achieved by initial treatment consisting of plasma exchange (PE), plasma infusion and corticosteroids, followed by vincristine and splenectomy. In view of the ongoing activity of TTP, treatment was initiated with rituximab, a chimaeric monoclonal antibody directed against the CD 20 antigen present on B lymphocytes. The patient received 4 weekly infusions of 375 mg/m2, each administered after the daily PE session and withholding PE until 48 hours later. Three weeks after the last infusion of rituximab a complete clinical and laboratory remission of this first episode of acute refractory TTP was documented. A concise review of the literature on the role of rituximab in patients with a first episode of acute plasma-refractory TTP suggests that rituximab in that situation may produce clinical remission in a significant proportion of patients, result in a lowered plasma requirement and avoid the complications of salvage immunosuppressive therapy. The use of rituximab in acute refractory TTP appears to be safe, with no excess infectious complications. We conclude that rituximab should be considered in TTP patients with acquired ADAMTS-13 deficiency who fail to respond clinically after 7-14 days of standard treatment with daily PE and glucocorticoids.

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The purpose of this investigation was to attempt to find some means of increasing the effective porosity and permeabil­ity of the producing sands of the Cut Bank Oil Field, with the hope that thereby the ultimate recovery of petroleum from this field may be increased. Although the percentage increase in production thus effected would undoubtedly be small, it would represent a substantial volume of petroleum in view of the great quantity of oil and gas present in this field.

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An acute injury to the triangular fibrocartilage complex (TFCC) with avulsion of the foveal attachment can produce distal radioulnar joint (DRUJ) instability. The avulsed TFCC is translated distally so the footprint will be bathed in synovial fluid from the DRUJ and will become covered in synovitis. If the TFCC fails to heal to the footprint, then persistent instability can occur. The authors describe a surgical technique indicated for the treatment of persistent instability of the DRUJ due to foveal detachment of the TFCC. The procedure utilizes a loop of palmaris longus tendon graft passed through the ulnar aspect of the TFCC and into an osseous tunnel in the distal ulna to reconstruct the foveal attachment. This technique provides stability of the distal ulna to the radius and carpus. We recommend this procedure for chronic instability of the DRUJ due to TFCC avulsion, but recommend that suture repair remain the treatment of choice for acute instability. An arthroscopic assessment includes the trampoline test, hook test, and reverse hook test. DRUJ ballottement under arthroscopic vision details the direction of instability, the functional tear pattern, and unmasks concealed tears. If the reverse hook test demonstrates a functional instability between the TFCC and the radius, then a foveal reconstruction is contraindicated, and a reconstruction that stabilizes the radial and ulnar aspects of the TFCC is required. The foveal reconstruction technique has the advantage of providing a robust anatomically based reconstruction of the TFCC to the fovea, which stabilizes the DRUJ and the ulnocarpal sag.

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A problem with a practical application of Varian.s Weak Axiom of Cost Minimization is that an observed violation may be due to random variation in the output quantities produced by firms rather than due to inefficiency on the part of the firm. In this paper, unlike in Varian (1985), the output rather than the input quantities are treated as random and an alternative statistical test of the violation of WACM is proposed. We assume that there is no technical inefficiency and provide a test of the hypothesis that an observed violation of WACM is merely due to random variations in the output levels of the firms being compared.. We suggest an intuitive approach for specifying a value of the variance of the noise term that is needed for the test. The paper includes an illustrative example utilizing a data set relating to a number of U.S. airlines.

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One component systems are treated from the point of view of the Gibbs' phase rule.

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The importance of race as a factor in mental health status has been a topic of controversy. This study reviews the history of research in this area and examines racial variances in the relationship between selected socio-demographic variables and general well-being. The study also examines the appropriateness of an additive versus an interactive statistical model for this investigation.^ The sample consists of 6,913 persons who completed the General Well-Being Schedules as administered in the detailed component of the first National Health and Nutrition Examination Survey (NHANES I) conducted by the National Center for Health Statistics between April, 1971 and October, 1975. The sampling design is a multistage, probability sample of clusters of persons in area based segments. Of the 6,913 persons, 873 are Black.^ Unlike other recent community based mental health studies, this study revealed significant differences between the general well-being of Blacks and Whites. Blacks continued to exhibit significantly lower levels of well-being even after adjustments were made for income, education, marital status, sex, age and place of residence. Statistical interaction was found between race and sex with Black females reporting lower levels of well-being than either Black or White males or their White female counterparts.^ The study includes a detailed review of the NHANES I sample design. It is shown that selected aspects of the design make it difficult to render appropriate national comparisons of Black-White differences. As a result conclusions pertaining to these differences based on NHANES I may be of questionable validity. ^

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This article presents and technically describes a new field spectro-goniometer system for the ground-based characterization of the surface reflectance anisotropy under natural illumination conditions developed at the Alfred Wegener Institute (AWI). The spectro-goniometer consists of a Manual Transportable Instrument platform for ground-based Spectro-directional observations (ManTIS), and a hyperspectral sensor system. The presented measurement strategy shows that the AWI ManTIS field spectro-goniometer can deliver high quality hemispherical conical reflectance factor (HCRF) measurements with a pointing accuracy of ±6 cm within the constant observation center. The sampling of a ManTIS hemisphere (up to 30° viewing zenith, 360° viewing azimuth) needs approx. 18 min. The developed data processing chain in combination with the software used for the semi-automatic control provides a reliable method to reduce temporal effects during the measurements. The presented visualization and analysis approaches of the HCRF data of an Arctic low growing vegetation showcase prove the high quality of spectro-goniometer measurements. The patented low-cost and lightweight ManTIS instrument platform can be customized for various research needs and is available for purchase.

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Background: In Argentina, abortion has been decriminalized under certain circumstances since the enactment of the Penal Code in 1922. Nevertheless, access to abortion under this regulatory framework has been extremely limited in spite of some recent changes. This article reports the findings of the first phase of an operations research study conducted in the Province of Santa Fe, Argentina, regarding the implementation of the local legal and safe abortion access policy. Methods: The project combined research and training to generate a virtuous circle of knowledge production, decision-making, and the fostering of an informed healthcare policy. The project used a pre-post design of three phases: baseline, intervention, and evaluation. It was conducted in two public hospitals. An anonymous self-administered questionnaire (n = 157) and semi-structured interviews (n = 27) were applied to gather information about tacit knowledge about the regulatory framework; personal opinions regarding abortion and its decriminalization; opinions on the requirements needed to carry out legal abortions; and service’s responses to women in need of an abortion. Results: Firstly, a fairly high percentage of health care providers lack accurate information on current legal framework. This deficit goes side by side with a restrictive understanding of both health and rape indications. Secondly, while a great majority of health care providers support abortion under the circumstances consider in the Penal Code, most of them are reluctant towards unrestricted access to abortion. Thirdly, health care providers’ willingness to perform abortions is noticeably low given that only half of them are ready to perform an abortion when a woman’s life is at risk. Willingness is even lower for each of the other current legal indications. Conclusions: Findings suggest that there are important challenges for the implementation of a legal abortion policy. Results of the study call for specific strategies targeting health care providers in order to better inform about current legal abortion regulations and to sensitize them about abortion social determinants. The interpretation of the current legal framework needs to be broadened in order to reflect a comprehensive view of the health indication, and stereotypes regarding women’s sexuality and abortion decisions need to be dismantled.

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An investigation of ~1-m.y.-old dikes and lavas from the north wall of the Hess Deep Rift (2°15'N, 101°30'W) collected during Alvin expeditions provides a detailed view of the evolution of fast spreading oceanic crust. The study area encompasses 25 km of an east-west flow line, representing ~370,000 years of crustal accretion at the East Pacific Rise. Samples analyzed exhibit depleted incompatible trace element abundances and ratios [(La/Sm)N < 1]. Indices of fractionation (MgO), and incompatible element ratios (La/Sm, Nb/Ti) show no systematic trends along flow line. Rather, over short (<4 m) and long (~25 km) distances, significant variations are observed in major and trace element concentrations and ratios. Modeling of these variations attests to the juxtaposition of dikes of distinct parental magma compositions. These findings, combined with studies of segmentation of the subaxial magma chamber and lateral magma transport in dikes along rift-dominated systems, suggest a more realistic model of the magmatic system underlying the East Pacific Rise relative to the commonly assumed twodimensional model. In this model, melts from a heterogeneous mantle feed distinct portions of a segmented axial magma reservoir. Dikes emanating from these distinct reservoirs transport magma along axis, resulting in interleaved dikes and host lavas with different evolutionary histories. This model suggests the use of axial or flow line lava compositions to infer the evolution of axial magma chambers should be approached with caution because dikes may never erupt lava or may transport magma significant distances along axis and erupt lavas far from their axial magma chamber of origin.

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In view of the drastic growth in the Canadian Inuit population, the rising costs of living, the missing job and income alternatives and the high unemployment rate in the arctic, efforts are being made to make use of the muskox populations in order to provide additional sources of food and/or revenue. The present paper attempts to review the course of muskox utilization in the Canadian Arctic and to tentatively assess its present as weIl as its future economic importance. Starting with the pre-European status of muskoxen in Canada, the drastic reduction in numbers resulting from the combined efforts of hide traders, whalers and expedition parties in the 19th and early 20th centuries, the impact of the legal protection and the recovery since 1917 are being described. Establishing muskox farms with semi-domesticated herds failed in Canada in the 1970's. Since 1969, though, increasing numbers of animals have been allotted to many Inuit communities, and despite the fact that most of the animals were primarily used for subsistence purposes, some communities could reserve part of their quotas for trophy (sport) hunters. While controlled sustainable subsistence and trophy hunts may eventually be carried out over the whole muskox range, including recently colonized northern Quebec, commercial harvesting for meat, hides and wool, introduced in 1981, will at least for some time be restricted to Banks and Victoria islands which at present show 78 % of the Canadian muskox population and 94 % of the overall quota.