1,415 research outputs found
One size does not fit all… An economic development perspective on the asymmetric impact of Patents on R&D
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
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
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
Technological innovation in the traditional olive orchard management: advances and opportunities to the Northeastern region of Portugal
In Portugal, the olive orchard is the most representative agricultural crop and one of
the most impactful on the national economy. Therefore, a production structure accompanying the
technological advances in this field would be expected; however, such a structure has not yet been
realized, especially within traditional systems. Thus, taking northeastern Portugal as a case study,
where a great expression of traditional orchards is visible, the following aspects are addressed
within this paper: the region’s biophysical framework, the olive orchard’s environmental and socio-
economic importance and its current management practices and associated pressures. As a result
of that assessment, which demonstrates a low level of sustainability for traditional olive orchards,
mainly in terms of economic viability, the most effective and simple solution is to act appropriately
on factors that interfere with the crop yield, namely, irrigation and fertilization issues. With that
purpose, a multiscale precision oliviculture system is also presented that is being developed in order
to support decision making in traditional olive orchard management, aiming to obtain economically
efficient productions based on eco-friendly cultural practices. Throughout the entire process, it is
essential to ensure stakeholder engagement, in particular, olive growers, so that they recognize the
effectiveness of potential measures that may avoid the reconversion/abandonment of the traditional
olive production system.info:eu-repo/semantics/publishedVersio
How can a changing climate influence the productivity of traditional olive orchards? Regression analysis applied to a local case study in Portugal
Nowadays, the climate is undoubtedly one of the main threats to the sustainability of olive
orchards, especially in the case of rainfed traditional production systems. Local warming, droughts,
and extreme weather events are some of the climatological factors responsible for environmental
thresholds in relation to crops being exceeded. The main objective of this study was to investigate the
influence of microclimatic variability on the productivity of traditional olive orchards in a municipality
located in northeastern Portugal. For this purpose, official data on climate, expressed through agrobioclimatic
indicators, and olive productivity for a 21-year historical period (2000–2020) were used
to evaluate potential correlations. In addition, a comprehensive regression analysis involving the
dataset and the following modeling scenarios was carried out to develop regression models and
assess the resulting predictions: (a) Random Forest (RF) with selected features; (b) Ordinary Least-
Squares (OLS) with selected features; (c) OLS with correlation features; and (d) OLS with all features.
For the a and b scenarios, features were selected applying the Recursive Feature Elimination with
Cross-Validation (RFECV) technique. The best statistical performance was achieved considering
nonlinearity among variables (a scenario, R2 = 0.95); however, it was not possible to derive any
model given the underlying methodology to this scenario. In linear regression applications, the best
fit between model predictions and the real olive productivity was obtained when all the analyzed
agro-bioclimatic indicators were included in the regression (d scenario, R2 = 0.85). When selecting
only the most relevant indicators using RFECV and correlation techniques, moderate correlations
for the b and c regression scenarios were obtained (R2 of 0.54 and 0.49, respectively). Based on
the research findings, especially the regression models, their adaptability to other olive territories
with similar agronomic and environmental characteristics is suggested for crop management and
regulatory purposes.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for
financial support through national funds FCT/MCTES (PIDDAC) to CIMO (UIDB/00690/2020 and
UIDP/00690/2020) and SusTEC (LA/P/0007/2020). This work was carried out under the Project
“OleaChain: Competências para a sustentabilidade e inovação da cadeia de valor do olival tradicional
no Norte Interior de Portugal” (NORTE-06-3559-FSE-000188), an operation to hire highly qualified
human resources, funded by NORTE 2020 through the European Social Fund (ESF).info:eu-repo/semantics/publishedVersio
Isoperimetric problems of the calculus of variations with fractional derivatives
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
Enumeration and characterization of arsenic-tolerant diazotrophic bacteria in a long-term heavy-metal-contaminated soil
The abundance of arsenic-tolerant diazotrophic
bacteria was compared in a long-term contaminated
soil versus a non-contaminated one. In addition, the
characterization of tolerant diazotrophic bacteria was
carried out. Differences in the number of heterotrophic
N2 fixers were found between soils. Contaminated soil
showed a decrease in the microbial population size of
about 80%, confirming the great sensitivity of this
group of soil bacteria to metals. However, quantitative
analysis of the response to increased doses of arsenic
reveals that the proportion of the culturable diazotrophic
community tolerant to arsenic was identical for both
soils (contaminated and non-contaminated). Twentytwo
arsenic-tolerant diazotrophic isolates were obtained
and further characterized. 16S ribosomal DNA sequence
analysis revealed that these bacterial isolates
were distributed among four taxons (Actinobacteria,
Firmicutes, γ-Proteobacteria, and β-Proteobacteria).
Most genera recovered from the contaminated soil were
also found in the uncontaminated soi
Co-gasification of glycerol/fat mixtures in a downflow fixed bed reactor: Preliminary results
The aim of this work was to assess the technical viability of glycerol/fat co-gasification. The gasification performance was
studied in a downflow fixed bed reactor using steam as oxidizing agent. Tests were performed with a mixture of 10% of fat
and 52% of water, and the effect of temperature was evaluated in the 800 oC to 950 oC range. Samples of dry gas from the
gasifier were collected and analysed by gas chromatography in order to determine the CO, CO2, CH4 and H2 content. The
results revealed that the co-gasification of glycerol/fat mixtures seems to be a feasible technical option. Best results of the
gasification parameters were obtained at the highest tested temperature, 950 ◦C.This work was supported by Portugal 2020 [POCI-01-0145-FEDER-024067] and Fundação para a Ciência e
Tecnologia [SFRH/BD/137913/2018].info:eu-repo/semantics/publishedVersio
Fatores prognósticos em câncer de cólon localmente avançado tratado com ressecção extendida
The impact of clinical, pathologic, and surgical variables on the postoperative morbidity, mortality, and survival of patients undergoing extended resections of colon carcinoma were evaluated. METHODS: The medical records of 95 patients who underwent extended resections for colon carcinoma between 1953 and 1996 were reviewed. In all cases, in addition to colectomy, 1 or more organs and/or structures were resected en bloc due to a macroscopically based suspicion of tumor invasion. The clinical, pathologic, and surgical parameters were analyzed. Overall survival rates were analyzed according to the method of Kaplan and Meier. Multivariate analysis was performed using the Cox proportional hazards model. RESULTS: Eighty-six patients were treated by curative surgeries and the remaining by palliative resections. Invasion of the organs and/or adjacent structures and regional lymph nodes was found microscopically in 48 and 31 patients, respectively. The median follow-up without postoperative mortality was 47.7 months. The 5-year overall survival rates was 52.6%. The 5-year overall survival rates for patients undergoing curative and palliative surgeries was 58.3% and 0%, respectively. The mean survival time in the palliative surgery group was 3.1 months. Multivariate analysis showed that Karnofsky performance status was strongly related to the risk of postoperative complications (P = .01), and postoperative deaths were associated with the type of surgery and Karnofsky performance status at the time of admission (P = .001). CONCLUSIONS: Some patients with locally advanced colon adenocarcinomas undergoing extended resections have a 5-year overall survival rates of 58.3%. Patients could benefit from palliative-intent procedures, but these measures should cautiously be indicated and avoided in patients with low Karnofsky performance status due to high rates of postoperative mortality and poor survival.Foi avaliado o impacto de variáveis clínicas, patológicas e cirúrgicas na morbidade e mortalidade pós operatórias de pacientes submetidos à ressecção extendida de carcinoma do cólon. MÉTODOS: Prontuários médicos de 95 pacientes submetidos á ressecção extendida de carcinoma de cólon entre os anos de 1953 e 1996 foram revisados. Em todos os casos, além de colectomia, um ou mais órgãos e/ou estruturas foram ressecados em bloco devido á suspeição de invasão tumoral macroscópica. As variáveis clínicas, patológicas e cirúrgicas foram analizadas. As taxas de sobrevida global foram analizadas de acordo com o método de Kaplan and Meier. A análise multivariada foi realizada empregando-se o modelo de risco proporcional de Cox. RESULTADOS: Oitenta e seis pacientes foram tratados com cirurgia curativa e o restante com ressecção paliativa. Invasão microscópica de órgãos e/ou estruturas adjacentes e linfonodos regionais foi encontrada em 48 e 31 pacientes respectivamente. O tempo de seguimento mediano, sem mortalidade pós operatória, foi de 47.7 meses. A taxa de sobrevida global em 5 anos foi de 52.6%. A taxa de sobrevida global para pacientes submetidos à cirurgia curativa e paliativa foi de 58.3% e zero, respectivamente. A sobrevida mediana no grupo de pacientes com cirurgia paliativa foi de 3.1 meses. A análise multivariada mostrou que a performance status de Karnofsky fortemente correlacionou com risco de complicações pós operatórias (p=0.01), e que o risco de morte pós operatória estava associada com o tipo de cirurgia e a performance status de Karnofsky na admissão (p=0.001) CONCLUSÕES: Pacientes com adenocarcinoma de cólon localmente avançados submetidos à ressecção extendida têm taxa de sobrevida global em 5 anos de 58.3% Este tipo de cirurgia pode ser empregada com intuito paliativo, mas deve ter indicação criteriosa e ser evitada em pacientes com baixa performance status de Karnofsky devido às altas taxas de mortalidade pós operatória e baixa sobrevida
Объем остаточной тиреоидной ткани и эффективность постоперационной радиойодтерапии больных с дифференцированными формами рака щитовидной железы
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
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