879 resultados para Ability of innovation
Resumo:
Centrifugal countercurrent distribution (CCCD) in an aqueous two-phase system (TPS) is a resolute technique revealing sperm heterogeneity and for the estimation of the fertilizing potential of a given semen sample. However, separated sperm subpopulations have never been tested for their fertilizing ability yet. Here, we have compared sperm quality parameters and the fertilizing ability of sperm subpopulations separated by the CCCD process from ram semen samples maintained at 20 degrees C or cooled down to 5 degrees C. Total and progressive sperm motility was evaluated by computer-assisted analysis using a CASA system and membrane integrity was evaluated by flow cytometry by staining with CFDA/Pl. The capacitation state, staining with chlortetracycline, and apoptosis-related markers, such as phosphatidylserine (PS) translocation detected with Annexin V. and DNA damage detected by the TUNEL assay, were determined by fluorescence microscopy. Additionally, the fertilizing ability of the fractionated subpopulations was comparative assessed by zona binding assay (ZBA). CCCD analysis revealed that the number of spermatozoa displaying membrane and DNA alterations was higher in samples chilled at 5 degrees C than at 20 degrees C. which can be reflected in the displacement to the left of the CCCD profiles. The spermatozoa located in the central and right chambers (more hydrophobic) presented higher values (P<0.01) of membrane integrity, lower PS translocation (P<0.05) and DNA damage (P<0.001) than those in the left part of the profile, where apoptotic markers were significantly increased and the proportion of viable non-capacitated sperm was reduced. We have developed a new protocol to recover spermatozoa from the CCCD fractions and we proved that these differences were related with the fertilizing ability determined by ZBA, because we found that the number of spermatozoa attached per oocyte was significantly higher for spermatozoa recovered from the central and right chambers, in both types of samples. This is the first time, to our knowledge that sperm recovered from a two-phase partition procedure are used for fertilization assays. These results open up new possibilities for using specific subpopulations of sperm for artificial insemination or in vitro fertilization, not only regarding better sperm quality but also certain characteristics such as subpopulations enriched in spermatozoa bearing X or Y chromosome that we have already isolated or any other feature. (C) 2011 Elsevier B.V. All rights reserved.
Resumo:
This study determined the ability of psychrotrophic Clostridium strains isolated from vacuum-packaged beefs and abattoir environments to cause 'blown-pack' spoilage of vacuum-packaged beef stored at 2 and 15 degrees C. The influence of shrinking temperatures (83, 84 and 87 degrees C) and vacuum pressure (6 and 9 mbar) on the occurrence of such spoilage as well as the effects of simulated transportation (500 km) on the integrity of packages was determined. At 15 degrees C and 2 degrees C, twelve and six strains caused 'blown-pack' spoilage, respectively. The combination of vacuum pressure (9 mbar) combined with shrinking temperature (87 degrees C) retarded the occurrence of spoilage. The simulated transportation under the experimental conditions did not affect the integrity of packages. More studies that assess the factors that may contribute for the occurrence of 'blown-pack' spoilage should be performed to avoid the occurrence of such spoilage during its shelf-life. (C) 2012 Elsevier Ltd. All rights reserved.
Resumo:
Background: The most frequent and malignant brain cancer is glioblastoma multiforme (GBM). In gliomas, tumor progression and poor prognosis are associated with the tumorigenic ability of the cells. U87MG cells (wild-type p53) are known to be tumorigenic in nude mice, but T98G cells (mutant p53) are not tumorigenic. We investigated the proteomic profiling of these two cell lines in order to gain new insights into the mechanisms that may be involved in tumorigenesis. Results: We found 24 differentially expressed proteins between T98G and U87MG cells. Gene Ontology supports the notion that over-representation of differentially expressed proteins is involved in glycolysis, cell migration and stress oxidative response. Among those associated with the glycolysis pathway, TPIS and LDHB are up-regulated in U87MG cells. Measurement of glucose consumption and lactate production suggests that glycolysis is more effective in U87MG cells. On the other hand, G6PD expression was 3-fold higher in T98G cells and this may indicate a shift to the pentose-phosphate pathway. Moreover, GRP78 expression was also three-fold higher in T98G than in U87MG cells. Under thapsigargin treatment both cell lines showed increased GRP78 expression and the effect of this agent was inversely correlated to cell migration. Quantitative RT-PCR and immunohistochemistry of GRP78 in patient samples indicated a higher level of expression of GRP78 in grade IV tumors compared to grade I and non-neoplastic tissues, respectively. Conclusions: Taken together, these results suggest an important role of proteins involved in key functions such as glycolysis and cell migration that may explain the difference in tumorigenic ability between these two glioma cell lines and that may be extrapolated to the differential aggressiveness of glioma tumors.
Resumo:
Listeria monocytogenes is a pathogen capable of adhering to many surfaces and forming biofilms, which may explain its persistence in food processing environments. This study aimed to genetically characterise L monocytogenes isolates obtained from bovine carcasses and beef processing facilities and to evaluate their adhesion abilities. DNA from 29 L monocytogenes isolates was subjected to enzymatic restriction digestion (Ascii and Apal), and two clusters were identified for serotypes 4b and 112a, with similarities of 48% and 68%. respectively. The adhesion ability of the isolates was tested considering: inoculum concentration, culture media, carbohydrate source, NaCl concentration, incubation temperature, and pH. Each isolate was tested at 10(8) CFU mL(-1) and classified according to its adhesion ability as weak (8 isolates). moderate (17) or strong (4). The isolates showed higher adhesion capability in non-diluted culture media, media at pH 7.0, incubation at 25 degrees C and 37 degrees C, and media with NaCl at 5% and 7%. No relevant differences were observed for adhesion ability with respect to the carbohydrate source. The results indicated a wide diversity of PFGE profiles of persistent L monocytogenes isolates, without relation to their adhesion characteristics. Also, it was observed that stressing conditions did not enhance the adhesion profile of the isolates. (C) 2012 Elsevier Ltd. All rights reserved.
Resumo:
In this study we compared the microleakage of conventional glass ionomer cement (GIC) restorations following the use of different methods of root caries removal. In vitro root caries were induced in 75 human root dentin samples that were divided in five groups of 15 each according to the method used for caries removal: in group 1 spherical carbide burs at low speed were used, in group 2 a hand-held excavator was used, and in groups 3 to 5 an Er,Cr:YSGG laser was used at 2.25 W, 40.18 J/cm(2) (group 3), 2.50 W, 44.64 J/cm(2) (group 4) and 2.75 W, 49.11 J/cm(2) (group 5). The air/water cooling during irradiation was set to 55%/65% respectively. All cavities were filled with GIC. Five samples from each group were evaluated by scanning electron microscopy (SEM) and the other ten samples were thermocycled and submitted to a microleakage test. The data obtained were compared by ANOVA followed by Fisher's test (pa parts per thousand currency sign0.05). Group 4 showed the lowest microleakage index (56.65 6.30; p < 0.05). There were no significant differences among the other groups. On SEM images samples of groups 1 and 2 showed a more regular interface than the irradiated samples. Demineralized dentin below the restoration was observed, that was probably affected dentin. Group 4 showed the lowest microleakage values compared to the other experimental groups, so under the conditions of the present study the method that provided the lowest microleakage was the Er,Cr:YSGG laser with a power output of 2.5 W yielding an energy density of 44.64 J/cm(2).
Resumo:
Trabajo para el doctorado oficial de perspectivas científicas sobre el turismo y la dirección de empresas turísticas, de la Facultad de Economía, Empresa y Turismo de la ULPGC.
Resumo:
From the institutional point of view, the legal system of IPR (intellectual property right, hereafter, IPR) is one of incentive institutions of innovation and it plays very important role in the development of economy. According to the law, the owner of the IPR enjoy a kind of exclusive right to use his IP(intellectual property, hereafter, IP), in other words, he enjoys a kind of legal monopoly position in the market. How to well protect the IPR and at the same time to regulate the abuse of IPR is very interested topic in this knowledge-orientated market and it is the basic research question in this dissertation. In this paper, by way of comparing study and by way of law and economic analyses, and based on the Austrian Economics School’s theories, the writer claims that there is no any contradiction between the IPR and competition law. However, in this new economy (high-technology industries), there is really probability of the owner of IPR to abuse his dominant position. And with the characteristics of the new economy, such as, the high rates of innovation, “instant scalability”, network externality and lock-in effects, the IPR “will vest the dominant undertakings with the power not just to monopolize the market but to shift such power from one market to another, to create strong barriers to enter and, in so doing, granting the perpetuation of such dominance for quite a long time.”1 Therefore, in order to keep the order of market, to vitalize the competition and innovation, and to benefit the customer, in EU and US, it is common ways to apply the competition law to regulate the IPR abuse. In Austrian Economic School perspective, especially the Schumpeterian theories, the innovation/competition/monopoly and entrepreneurship are inter-correlated, therefore, we should apply the dynamic antitrust model based on the AES theories to analysis the relationship between the IPR and competition law. China is still a developing country with relative not so high ability of innovation. Therefore, at present, to protect the IPR and to make good use of the incentive mechanism of IPR legal system is the first important task for Chinese government to do. However, according to the investigation reports,2 based on their IPR advantage and capital advantage, some multinational companies really obtained the dominant or monopoly market position in some aspects of some industries, and there are some IPR abuses conducted by such multinational companies. And then, the Chinese government should be paying close attention to regulate any IPR abuse. However, how to effectively regulate the IPR abuse by way of competition law in Chinese situation, from the law and economic theories’ perspective, from the legislation perspective, and from the judicial practice perspective, there is a long way for China to go!
Resumo:
Introduction. Neutrophil Gelatinase-Associated Lipocalin (NGAL) belongs to the family of lipocalins and it is produced by several cell types, including renal tubular epithelium. In the kidney its production increases during acute damage and this is reflected by the increase in serum and urine levels. In animal studies and clinical trials, NGAL was found to be a sensitive and specific indicator of acute kidney injury (AKI). Purpose. The aim of this work was to investigate, in a prospective manner, whether urine NGAL can be used as a marker in preeclampsia, kidney transplantation, VLBI and diabetic nephropathy. Materials and methods. The study involved 44 consecutive patients who received renal transplantation; 18 women affected by preeclampsia (PE); a total of 55 infants weighing ≤1500 g and 80 patients with Type 1 diabetes. Results. A positive correlation was found between urinary NGAL and 24 hours proteinuria within the PE group. The detection of higher uNGAL values in case of severe PE, even in absence of statistical significance, confirms that these women suffer from an initial renal damage. In our population of VLBW infants, we found a positive correlation of uNGAL values at birth with differences in sCreat and eGFR values from birth to day 21, but no correlation was found between uNGAL values at birth and sCreat and eGFR at day 7. systolic an diastolic blood pressure decreased with increasing levels of uNGAL. The patients with uNGAL <25 ng/ml had significantly higher levels of systolic blood pressure compared with the patients with uNGAL >50 ng/ml ( p<0.005). Our results indicate the ability of NGAL to predict the delay in functional recovery of the graft. Conclusions. In acute renal pathology, urinary NGAL confirms to be a valuable predictive marker of the progress and status of acute injury.
Resumo:
Precision Agriculture (PA) and the more specific branch of Precision Horticulture are two very promising sectors. They focus on the use of technologies in agriculture to optimize the use of inputs, so to reach a better efficiency, and minimize waste of resources. This important objective motivated many researchers and companies to search new technology solutions. Sometimes the effort proved to be a good seed, but sometimes an unfeasible idea. So that PA, from its birth more or less 25 years ago, is still a “new” management, interesting for the future, but an actual low adoption rate is still reported by experts and researchers. This work aims to give a contribution in finding the causes of this low adoption rate and proposing a methodological solution to this problem. The first step was to examine prior research about Precision Agriculture adoption, by ex ante and ex post approach. It was supposed as important to find connections between these two phases of a purchase experience. In fact, the ex ante studies dealt with potential consumer’s perceptions before a usage experience occurred, therefore before purchasing a technology, while the ex post studies described the drivers which made a farmer become an end-user of PA technology. Then, an example of consumer research is presented. This was an ex ante research focused on pre-prototype technology for fruit production. This kind of research could give precious information about consumer acceptance before reaching an advanced development phase of the technology, and so to have the possibility to change something with the least financial impact. The final step was to develop the pre-prototype technology that was the subject of the consumer acceptance research and test its technical characteristics.
Resumo:
Human activities strongly influence environmental processes, and while human domination increases, biodiversity progressively declines in ecosystems worldwide. High genetic and phenotypic variability ensures functionality and stability of ecosystem processes through time and increases the resilience and the adaptive capacity of populations and communities, while a reduction in functional diversity leads to a decrease in the ability to respond in a changing environment. Pollution is becoming one of the major threats in aquatic ecosystem, and pharmaceutical and personal care products (PPCPs) in particular are a relatively new group of environmental contaminants suspected to have adverse effects on aquatic organisms. There is still a lake of knowledge on the responses of communities to complex chemical mixtures in the environment. We used an individual-trait-based approach to assess the response of a phytoplankton community in a scenario of combined pollution and environmental change (steady increasing in temperature). We manipulated individual-level trait diversity directly (by filtering out size classes) and indirectly (through exposure to PPCPs mixture), and studied how reduction in trait-diversity affected community structure, production of biomass and the ability of the community to track a changing environment. We found that exposure to PPCPs slows down the ability of the community to respond to an increasing temperature. Our study also highlights how physiological responses (induced by PPCPs exposure) are important for ecosystem processes: although from an ecological point of view experimental communities converged to a similar structure, they were functionally different.
Resumo:
The original 'Örebro Musculoskeletal Pain Questionnaire' (original-ÖMPQ) has been shown to have limitations in practicality, factor structure, face and content validity. This study addressed these concerns by modifying its content producing the 'Örebro Musculoskeletal Screening Questionnaire' (ÖMSQ). The ÖMSQ and original-ÖMPQ were tested concurrently in acute/subacute low back pain working populations (pilot n = 44, main n = 106). The ÖMSQ showed improved face and content validity, which broadened potential application, and improved practicality with two-thirds less missing responses. High reliability (0.975, p < 0.05, ICC: 2.1), criterion validity (Spearman's r = 0.97) and internal consistency (α = 0.84) were achieved, as were predictive ability cut-off scores from ROC curves (112-120 ÖMSQ-points), statistically different ÖMSQ scores (p < 0.001) for each outcome trait, and a strong correlation with recovery time (Spearman's, r = 0.71). The six-component factor structure reflected the constructs originally proposed. The ÖMSQ can be substituted for the original-ÖMPQ in this population. Further research will assess its applicability in broader populations.
Resumo:
The Gaussian-2, Gaussian-3, Complete Basis Set-QB3, and Complete Basis Set-APNO methods have been used to calculate geometries of neutral clusters of water, (H2O)n, where n = 2–6. The structures are in excellent agreement with those determined from experiment and those predicted from previous high-level calculations. These methods also provide excellent thermochemical predictions for water clusters, and thus can be used with confidence in evaluating the structures and thermochemistry of water clusters.
Resumo:
The PM3 semiempirical quantum-mechanical method was found to systematically describe intermolecular hydrogen bonding in small polar molecules. PM3 shows charge transfer from the donor to acceptor molecules on the order of 0.02-0.06 units of charge when strong hydrogen bonds are formed. The PM3 method is predictive; calculated hydrogen bond energies with an absolute magnitude greater than 2 kcal mol-' suggest that the global minimum is a hydrogen bonded complex; absolute energies less than 2 kcal mol-' imply that other van der Waals complexes are more stable. The geometries of the PM3 hydrogen bonded complexes agree with high-resolution spectroscopic observations, gas electron diffraction data, and high-level ab initio calculations. The main limitations in the PM3 method are the underestimation of hydrogen bond lengths by 0.1-0.2 for some systems and the underestimation of reliable experimental hydrogen bond energies by approximately 1-2 kcal mol-l. The PM3 method predicts that ammonia is a good hydrogen bond acceptor and a poor hydrogen donor when interacting with neutral molecules. Electronegativity differences between F, N, and 0 predict that donor strength follows the order F > 0 > N and acceptor strength follows the order N > 0 > F. In the calculations presented in this article, the PM3 method mirrors these electronegativity differences, predicting the F-H- - -N bond to be the strongest and the N-H- - -F bond the weakest. It appears that the PM3 Hamiltonian is able to model hydrogen bonding because of the reduction of two-center repulsive forces brought about by the parameterization of the Gaussian core-core interactions. The ability of the PM3 method to model intermolecular hydrogen bonding means reasonably accurate quantum-mechanical calculations can be applied to small biologic systems.