10 resultados para creation of new knowledge
em BORIS: Bern Open Repository and Information System - Berna - Suiça
Resumo:
Many peptide hormone receptors are over-expressed in human cancer, permitting an in vivo targeting of tumors for diagnostic and therapeutic purposes. NPY receptors are novel and promising candidates in this field. Using in vitro receptor autoradiography, Y1 and Y2 receptors have been found to be expressed in breast carcinomas, adrenal gland and related tumors, renal cell carcinomas, and ovarian cancers in both tumor cells and tumor-associated blood vessels. Pathophysiologically, tumoral NPY receptors may be activated by endogenous NPY released from intratumoral nerve fibers or tumor cells themselves, and mediate NPY effects on tumor cell proliferation and tumoral blood supply. Clinically, tumoral NPY receptors may be targeted with NPY analogs coupled with adequate radionuclides or cytotoxic agents for a scintigraphic tumor imaging and/or tumor therapy.
Resumo:
Experimental models of tricuspid regurgitation (TR) are needed to study the percutaneous placement of prosthetic atrioventricular valves. The purpose of this study was to develop an appropriate simple and reproducible percutaneous experimental model for creation of tricuspid regurgitation. Tricuspid regurgitation was successfully created through papillary muscle avulsion using a guide-wire loop in seven sheep with regurgitation documented on right ventricular angiograms and a significant increase in heart rate and right atrial pressures. Acute onset of tricuspid regurgitation was poorly tolerated in one animal that died. Autopsy examinations showed avulsion of one papillary muscle in four animals and two papillary muscles in three animals.
Resumo:
PURPOSE: This study was conducted to create an animal model for thoracic aortic transection that is suitable for thoracic endograft research. MATERIALS AND METHODS: Percutaneous aortic transection creation was attempted in 12 sheep. A custom collapsible circumferential cutting device was inserted into the proximal descending thoracic aorta via a femoral approach with an 11-F delivery catheter. The device was deployed 2 cm distal to the left subclavian artery origin and rotated 20 times to create aortic transection. Aortic diameters, mean aortic pressures, and heart rates were tested for degrees of difference between measurements before and after the creation of transection. On necropsy, the extent of aortic damage was classified as none, nontransmural, or transmural, and aortic transection was classified as none, partial, or circumferential. RESULTS: On angiography, creation of transmural thoracic aortic transection was successful in 91.7% (11/12) of animals. Aortic transection was circumferential in 54.4% (6/11) of animals and partial in 45.6% (5/11) of animals. Mean aortic diameter was 19.6 +/- 3.4 mm (range 12-24 mm) pre-transection and 25.8 +/- 4.5 mm (range 17.8-33 mm) post-transection (P = .0003). Pre-transection, mean aortic pressure was 79 +/- 13.8 mmHg, and 64.6 +/- 15.8 mmHg 15 min post-transection (P = .041). Pre-transection, mean heart rate was 94.5 +/- 17.2 beats per minute (bpm), and 105.8 +/- 17.2 bpm 15 min post-transection (P = .0057). CONCLUSIONS: Thoracic aortic transection was successfully created percutaneously in most animals. The animals remained in hemodynamically stable condition for as long as 240 minutes after the creation of aortic injury. This percutaneous animal model is straightforward and may be of potential value for future thoracic endograft research.
Resumo:
It is often claimed that scientists can obtain new knowledge about nature by running computer simulations. How is this possible? I answer this question by arguing that computer simulations are arguments. This view parallels Norton’s argument view about thought experiments. I show that computer simulations can be reconstructed as arguments that fully capture the epistemic power of the simulations. Assuming the extended mind hypothesis, I furthermore argue that running the computer simulation is to execute the reconstructing argument. I discuss some objections and reject the view that computer simulations produce knowledge because they are experiments. I conclude by comparing thought experiments and computer simulations, assuming that both are arguments.
Resumo:
Roughly 90% of the gas-exchange surface is formed by alveolarization of the lungs. To the best of our knowledge, the formation of new alveoli has been followed in rats only by means of morphological description or interpretation of semiquantitative data until now. Therefore, we estimated the number of alveoli in rat lungs between postnatal days 4 and 60 by unambiguously counting the alveolar openings. We observed a bulk formation of new alveoli between days 4 and 21 (17.4 times increase from 0.8 to 14.3 millions) and a second phase of continued alveolarization between days 21 and 60 (1.3 times increase to 19.3 million). The (number weighted) mean volume of the alveoli decreases during the phase of bulk alveolarization from ∼593,000 μm(3) at day 4 to ∼141,000 μm(3) at day 21, but increases again to ∼298,000 μm(3) at day 60. We conclude that the "bulk alveolarization" correlates with the mechanism of classical alveolarization (alveolarization before the microvascular maturation is completed) and that the "continued alveolarization" follows three proposed mechanisms of late alveolarization (alveolarization after microvascular maturation). The biphasic pattern is more evident for the increase in alveolar number than for the formation of new alveolar septa (estimated as the length of the free septal edge). Furthermore, a striking negative correlation between the estimated alveolar size and published data on retention of nanoparticles was detected.
Resumo:
A common training plan in general internal medicine was a brave enterprise started in 2011 in accordance with the common objectives of the Swiss Society of General Medicine and the Swiss Society of Internal Medicine. The next challenge will be the dissolution of the two Societies and therefore the creation of an unique new association in 2015. This is an extraordinary opportunity to bring together the specific qualities of each association and to create a new society. Issues, objectives and secondary benefits expected from the creation of the largest national society of a medical discipline are explored as a joint discussion in this article.
Resumo:
The twenty-first century has seen a further dramatic increase in the use of quantitative knowledge for governing social life after its explosion in the 1980s. Indicators and rankings play an increasing role in the way governmental and non-governmental organizations distribute attention, make decisions, and allocate scarce resources. Quantitative knowledge promises to be more objective and straightforward as well as more transparent and open for public debate than qualitative knowledge, thus producing more democratic decision-making. However, we know little about the social processes through which this knowledge is constituted nor its effects. Understanding how such numeric knowledge is produced and used is increasingly important as proliferating technologies of quantification alter modes of knowing in subtle and often unrecognized ways. This book explores the implications of the global multiplication of indicators as a specific technology of numeric knowledge production used in governance. Combination of insights from anthropology of law, history of science, science and technology studies, sociology of quantification, economics and geography will appeal to those who are uncomfortable with the separation between 'theoretical' and 'empirical' approaches and with the current weakness of critique that address the main trends shaping the relations between capitalism, markets, law and democracy Theoretical discussion of the nature and historical formation of quantification will appeal to those who ask questions such as, 'What is new or different about our contemporary reliance on quantitative knowledge?' Groundbreaking empirical case studies uncover the social work and politics that often go into the making of indicators and explore the far-reaching effects and impacts of these numerical representations in specific settings
Resumo:
Endogenous development is defined as development that values primarily locally available resources and the way people organized themselves for that purpose. It is a dynamic and evolving concept that also embraces innovations and complementation from other than endogenous sources of knowledge; however, only as far as they are based on mutual respect and the recognition of cultural and socioeconomic self-determination of each of the parties involved. Experiences that have been systematized in the context of the BioAndes Program are demonstrating that enhancing food security and food sovereignty on the basis of endogenous development can be best achieved by applying a ‘biocultural’ perspective: This means to promote and support actions that are simultaneously valuing biological (fauna, flora, soils, or agrobiodiversity) and sociocultural resources (forms of social organization, local knowledge and skills, norms, and the related worldviews). In Bolivia, that is one of the Latin-American countries with the highest levels of poverty (79% of the rural population) and undernourishment (22% of the total population), the Program BioAndes promotes food sovereignty and food security by revitalizing the knowledge of Andean indigenous people and strengthening their livelihood strategies. This starts by recognizing that Andean people have developed complex strategies to constantly adapt to highly diverse and changing socioenvironmental conditions. These strategies are characterized by organizing the communities, land use and livelihoods along a vertical gradient of the available eco-climatic zones; the resulting agricultural systems are evolving around the own sociocultural values of reciprocity and mutual cooperation, giving thus access to an extensive variety of food, fiber and energy sources. As the influences of markets, competition or individualization are increasingly affecting the life in the communities, people became aware of the need to find a new balance between endogenous and exogenous forms of knowledge. In this context, BioAndes starts by recognizing the wealth and potentials of local practices and aims to integrate its actions into the ongoing endogenous processes of innovation and adaptation. In order to avoid external impositions and biases, the program intervenes on the basis of a dialogue between exogenous, mainly scientific, and indigenous forms of knowledge. The paper presents an analysis of the strengths and weaknesses of enhancing endogenous development through a dialogue between scientific and indigenous knowledge by specifically focusing on its effects on food sovereignty and food security in three ‘biocultural’ rural areas of the Bolivian highlands. The paper shows how the dialogue between different forms of knowledge evolved alongside the following project activities: 1) recuperation and renovation of local seeds and crop varieties (potato – Solanum spp., quinoa – Chenopodium quinoa, cañahua – Chenopodium pallidicaule); 2) support for the elaboration of community-based norms and regulations for governing access and distribution of non-timber forest products, such as medicinal, fodder, and construction plants; 3) revitalization of ethnoveterinary knowledge for sheep and llama breeding; 4) improvement of local knowledge about the transformation of food products (sheep-cheese, lacayote – Cucurbita sp. - jam, dried llama meat, fours of cañahua and other Andean crops). The implementation of these activities fostered the community-based livelihoods of indigenous people by complementing them with carefully and jointly designed innovations based on internal and external sources of knowledge and resources. Through this process, the epistemological and ontological basis that underlies local practices was made visible. On this basis, local and external actors started to jointly define a renewed concept of food security and food sovereignty that, while oriented in the notions of well being according to a collectively re-crafted world view, was incorporating external contributions as well. Enabling and hindering factors, actors and conditions of these processes are discussed in the paper.