1,802 research outputs found

    One size does not fit all… An economic development perspective on the asymmetric impact of Patents on R&D

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    Innovation is the building block of competitive advantages and thus economic policies are increasingly focused on creating stimulus to increase a country’s innovative performance and growth potential, namely through knowledge accumulation in general and R&D in particular. In this context, current policy trend seems to support the strengthening of Intellectual Property Rights (IPR), in particular, patent protection, with the argument that positive effects will emerge and would be extensive to all countries regardless their level of development. In this paper we question this “one size fits all” policy and assess how patent thicket affects knowledge productive investment taking into account countries’ development levels. Based on a panel of 95 countries over a ten-year period (1997-2006), our results show that patents have asymmetric impacts across countries development stages, evidencing pervious effects on technological leaders and positive ones on some laggards. Such evidence sustains that innovation policies be adjusted to countries development stages.growth models; R&D; patents; economic development

    Does Patenting negatively impact on R&D investment?An international panel data assessment

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    Although the conventional R&D-patents relationship is a long stand and relatively undisputed issue within the innovation literature, the reverse causality, in particular, the potential for a negative impact of patents over R&D has only recently received wide attention boosting interesting (mainly) theoretical debates. The macroeconomic perspective on this issue, however, remains largely unexplored. In fact, no evidence exists that ruled out the possibility of asymmetric effects of patents on R&D in accordance to the level of GDP in general, and to ‘convergence clubs’ in particular. Using panel data estimation methods on a sample of 88 countries, over an eight-year period (1996-2003), and controlling for clubs of convergence to account for differences on countries’ stages of economic development, we found mix support to the negativity of patent on R&D investment. The accumulated patents positively impact on R&D intensity for the set of less developed countries whereas no statistically significant effect emerges in the case of higher developed converge clubs; restricting the highest developed convergence club down to countries with a R&D intensity above 3%, the negativity reverse causality arises, corroborating the asymmetric impact of patents on R&D investment. We further demonstrate that albeit causality appears to be stronger in the most intuitive appealing traditional direction, evidence supports the theoretical conveyed double causality between R&D and Patent.Patents; R&D; panel data; convergence clubs

    Searching for clusters in tourism. A quantitative methodological proposal

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    The tourism industry is one of Europe’s leading employers, and for many regions highly dependent on tourists’ spending, innovation is the difference between growth and stagnation. Thus, at a regional level, tourism may function as a driving force of socioeconomic development and thus contribute to the demise of regional disparities. Such lever effect is usually associated to a geographical concentration abusively denominated of clusters. Most of the studies within the tourism industry identify clusters resorting to simplistic analyses of geographic location measures or experts’ opinions. These latter tend to neglect the essence of the cluster concept, namely the inter-linkages among regional actors. In the present paper, we propose a methodology to rigorously identify tourism clusters, stressing the importance of networks and cooperation between agents.Clusters; Tourism; Methodology

    Isoperimetric problems of the calculus of variations with fractional derivatives

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    In this paper we study isoperimetric problems of the calculus of variations with left and right Riemann-Liouville fractional derivatives. Both situations when the lower bound of the variational integrals coincide and do not coincide with the lower bound of the fractional derivatives are considered.Comment: Submitted 02-Oct-2009; revised 30-Jun-2010; accepted 10-May-2011; for publication in the journal Acta Mathematica Scienti

    Perceptions in Living Kidney Donation: What ProtagonistsThink and Feel

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    Abstract Background Although donor perceptions of donation have been evaluated in several programs, evaluation of associated recipients has not been as frequent. Purpose Our aim was to evaluate and compare after transplantation, donor and recipient perceptions of donation. Methods After transplantation 35 recipients and 45 donors completed a sociodemographic and a donation perception questionnaire. We applied the Fisher test to descriptive (absolute and relative frequency) data. Results 57.8% of donors were female and 62.9% of recipients male. 53.3% of donors were siblings, 44.5% parents, and 2.2% a daughter. Most recipients (71.9%) thought that the donation was the donors' initiative and 21.9% that it was suggested by medical team. 96.4% responded that it was the donor's wish that determined their decision; 51.4% had serious or some doubts about accepting the option, but for 48.6% it was an easy decision. Among the donors, 88.9% decided by themselves and 8.9% were asked for donation. For 91.1%, their wish was the main reason of the decision, but 8.9% felt a moral obligation; 77.8% thought it was an easy decision, and 17.8% hesitated a little 84.4% were not worried about their future health. Conclusions Altruistic motivations were predominant in both groups. Most recipients thought that the motivation for donation was self-determined, a finding that agreed with donor perceptions. Perceptions about the quality of and changes in emotional relationship were the same in both groups. Donors and recipients referred to the donation process as positive, but there were some negative emotions and perceptions

    Объем остаточной тиреоидной ткани и эффективность постоперационной радиойодтерапии больных с дифференцированными формами рака щитовидной железы

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    Резюме. У 210 больных с дифференцированными формами рака щитовидной железы изучено влияние массы участков остаточной ткани щитовидной железы (ОТЩЖ) на эффективность радиойодтерапии (РЙТ). Через 4–6 нед после хирургического лечения выполняли диагностическую сцинтиграфию с 70–80 МБк 131I, по данным которой на основании эллипсоидной модели рассчитывали объем ОТЩЖ. РЙТ проводили активностями 1,9–4,7 ГБк, контрольную сцинтиграфию выполняли через 4–6 мес. Эффективность первого курса РЙТ при объеме ОТЩЖ 1 см3 и менее составляла 88,9%, при объеме более 4 см3 — 69,3% (р < 0,05). Установлена достоверная корреляция между объемом ОТЩЖ и эффективностью первого курса РЙТ. При наличии нескольких участков ОТЩЖ эффективность РЙТ определяется не столько их количеством и суммарным объемом, сколько объемом каждого участка. Ключевые слова: дифференцированный рак щитовидной железы, тиреоидэктомия, радиойодтерапия, остаточная ткань щитовидной железы.Summary. The influence of the mass of the residual thyroid tissue (RTT) on the efficacy of radioiodine therapy (RT) was investigated in 210 patients with differentiated forms of thyroid cancer (DFTC). 4 to 6 weeks after surgery, diagnostic 131J scintigraphy (70–80 MBq) was applied. On the basis of data obtained, the RTT size was measured based on an ellipsoidal model. Activities applied in RT ranged between 1,9–4,7 GBq; control scintigraphy was performed in 4 to 6 months. The efficacy of the first RT course was 88,9% in patients with RTT of 1 cm3 or smaller and 69,3% in patients with RTT of 4 cm3 or larger (р<0,05). A significant correlation was found between the size of RTT and the efficacy of the first RT course. In cases where there were several RTT areas, the RT efficacy depended on the overall size of each area rather than on the number of such areas. Key Words: differentiated thyroid cancer, thyreoidectomy, radioiodine therapy, residual thyroid tissue

    Diagnóstico do estado nutritivo de uma plantação jovem de olival

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    Na Primavera de 2009 foi instalado em S. Pedro Vale do Conde, em Mirandela, um olival em duas densidades 4 x 1,35 m e 7 x 3,5 m. Na densidade 4 x 1,35 m foram instaladas três cultivares: Cobrançosa, Negrinha e Arbequina. Na densidade 7 x 3,5 m foram instaladas as cultivares: Cobrançosa, Madurai e Verdeal Transmontana. O olival foi instalado num solo franco-arenoso, com 1% de matéria orgânica e pH em água de 4,3. No Verão seguinte à instalação iniciou-se a monitorização do estado nutritivo das plantas através de análise foliar efetuada duas vezes ao ano, em julho e janeiro. A concentração de azoto nas folhas revelou elevada variação nas duas primeiras datas de amostragem, com estabilização dos valores na gama de concentrações adequadas a partir do segundo ano. Não foram registadas diferenças significativas entre cultivares. Os valores de fósforo e potássio revelaram-se com bastante variabilidade, com tendência para estabilizarem dentro da gama de concentrações adequadas. A concentração de cálcio nas folhas manteve-se abaixo do limite critico de deficiência refletindo o pH particularmente baixo do solo. Os valores de magnésio também se mantiveram baixos, frequentemente abaixo do limite de concentrações críticas de deficiência. O boro revelou elevada diferença entre as amostragens de Verão e de Inverno, aspeto característico deste elemento, com valores mais altos no Verão. A Madurai parece manter valores estatisticamente mais elevados que as restantes cultivares. Apesar da Importância da monitorização do estado nutritivo das plantas nas fases juvenis, a elevada variabilidade encontrada parece dificultar a definição da melhor estratégia de fertilização

    Reactive phenotypes after acute and chronic NK‐cell activation

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    J Biol Regul Homeost Agents. 2004 Jul-Dec;18(3-4):331-4. Reactive phenotypes after acute and chronic NK-cell activation. Lima M, Almeida J, Teixeira MA, Santos AH, Queirós ML, Fonseca S, Moura J, Gonçalves M, Orfão A, Pinto Ribeiro AC. Service of Clinical Hematology, Laboratory of Cytometry, Hospital Geral de Santo António, Porto, Portugal. [email protected] Abstract Several phenotypic changes have been shown to occur after NK-cell stimulation, involving molecules that have been proved to regulate NK-cell migration into tissues and NK-cell activation and proliferation as well as target cell recognition and killing. Here, we review the reactive phenotypes observed in vivo after acute and chronic NK-cell activation. PMID: 15786700 [PubMed - indexed for MEDLINE

    Does Simulated Spaceflight Modify Epigenetic Status During Bone Remodeling?

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    Little is known about the effects of spaceflight conditions on epigenetics. The term epigenetics describes changes to the genome that can affect expression of a gene without changes to the sequence of DNA. Epigenetic processes are thought to underlie cellular differentiation, where transcription of specific genes occurs in response to key stimuli, and may be heritable - passing from one cell to its daughter cell. We hypothesize that the mechanical environment during spaceflight, namely microgravity-induced weightlessness or exercise regulate gene expression in the osteoblast-lineage cells both to control bone formation by osteoblasts and bone resorption by osteoclasts, which continually shapes bone structure throughout life. Similarly we intend to evaluate how radiation regulates these same bone cell activity and differentiation related genes. We further hypothesize that the regulation in bone cell gene expression is at least partially controlled through epigenetic mechanisms of methylation or small non-coding RNA (microRNAs). We have acquired preliminary data suggesting that global genome methylation is modified in response to axial compression of the tibia - a model of exercise. We intend to pursue these hypotheses wherein we will evaluate changes in gene expression and, congruently, changes in epigenetic state in bones from mice subjected to the aforementioned conditions: hindlimb unloading to simulate weightlessness, axial compression of the tibia, or radiation exposure in order to gain insight into the role of epigenetics in spaceflight-induced bone loss
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