Path-dependence, expectativas e regulação econômica : elementos de análise a partir de uma perspectiva pós-keynesiana

O artigo busca fazer uma relação entre a ocorrência de path-dependence, a natureza expectacional do investimento e as flutuações econômicas, a partir de um referencial pós-keynesiano de análise. Em um ambiente não-ergódico, a fim de que o sistema tenha uma relativa estabilidade no tempo, a regulação econômica requer muito mais do que simples ajustamentos incrementais. Tornam-se necessárias, e possíveis, modificações qualitativas do sistema econômico. Tais modificações são analisadas a partir do conceito de bifurcação.

Fiber average size and distribution dependence on the electrospinning parameters of poly(vinylidene fluoride trifluoroethylene)) membranes for biomedical applications

Poly(vinylidene fluoride-trifluoethylene) electrospun membranes were obtained from a blend of dimethylformamide (DMF) and methylethylketone (MEK) solvents. The inclusion of the MEK to the solvent system promotes a faster solvent evaporation allowing complete polymer crystallization during the jet travelling between the tip and the grounded collector. Several processing parameters were systematically changed to study their influence on fiber dimensions. Applied voltage and inner needle diameter do not have large influence on the electrospun fiber average diameter but in the fiber diameter distribution. On the other hand, the increase of the distance between the needle tip to collector results in fibers with larger average diameter. Independently on the processing conditions, all mats are produced in the electroactive phase of the polymer. Further, MC-3T3-E1cell adhesion was not inhibited by the fiber mats preparation, indicating their potential use for biomedical applications.

Temperature dependence of the electrical conductivity of vapor grown carbon nanofiber/epoxy composites with different filler dispersion levels

The influence of the dispersion of vapor grown carbon nanofibers (VGCNF) on the electrical properties of VGCNF/epoxy composites has been studied. A homogeneous dispersion of the VGCNF does not imply better electrical properties. The presence of well distributed clusters appears to be a key factor for increasing composite conductivity. It is also shown that the main conduction mechanism has an ionic nature for concentrations below the percolation threshold, while above the percolation threshold it is dominated by hopping between the fillers. Finally, using the granular system theory it is possible to explain the origin of conduction at low temperatures.

Carbon Nanofiber Type and Content Dependence of the Physical Properties of Carbon Nanofiber Reinforced Polypropylene Composites

The variation of the physical properties of four differ- ent carbon nanofibers (CNFs), based-polymer nano- composites incorporated in the same polypropylene (PP) matrix by twin-screw extrusion process was investigated. Nanocomposites fabricated with CNFs with highly graphitic outer layer revealed electrical isolation-to-conducting behaviors as function of CNF’s content. Nanocomposites fabricated with CNFs with an outer layer consisting on a disordered pyro- litically stripped layer, in contrast, revealed better mechanical performance and enhanced thermal sta- bility. Further, CNF’s incorporation into the polymer increased the thermal stability and the degree of crystallinity of the polymer, independently on the filler content and type. In addition, dispersion of the CNFs’ clusters in PP was analyzed by transmitted light opti- cal microscopy, and grayscale analysis (GSA). The results showed a correlation between the filler concentration and the variance, a parameter which measures quantitatively the dispersion, for all composites. This method indicated a value of 1.4 vol% above which large clusters of CNFs cannot be dispersed effectively and as a consequence only slight changes in mechanical performance are observed. Finally, this study establishes that for tailoring the physical properties of CNF based-polymer nanocomposites, both adequate CNFs structure and content have to be chosen.

Dependence relationship between the critical quality factors and social impact

This paper shows the results of the empirical study conducted in 186 tourist accommodation businesses in Spain certified under the "Q for Tourist Quality", own System Quality Management. It was raised with the purpose of analyzing the structure of the relationship between critical quality factors and results-social impact, how they operate and the level of their influence on obtaining these results within the company. Starting from a deep theoretical revision we propose a theoretical model together with the hypotheses to be tested, and we proceed to validation using the technique of Structural Equation Models. The results obtained show that companies wishing to improve their social impact should take into account that leadership is the most important factor to achieve it. Leadership indirectly affects the social impact through its influence on alliances and resources, quality policy/planning, personnel management and learning.

Voltammetric oxidation of drugs of abuse III. Heroin and metabolites

The oxidative behavior of heroin in aqueous solution is reported. In order to identify its oxidation peaks, several metabolites, 6-monoacetylmorphine, 3-monoacetylmorphine and norheroin, were synthesized and their electrochemical behavior studied using differential pulse voltammetry. The anodic waves observed for heroin correspond to the oxidation of the tertiary amine group and its follow-up product (secondary amine), and to the oxidation of the phenolic group obtained from hydrolysis, at alkaline pHs, of the 3-acetyl group. The results enabled a new oxidative mechanism for heroin to be proposed in which a secondary amine, norheroin, and an aldehyde are obtained. The voltammetric behavior of 6-monoacetylmorphine and morphine was found to be similar demonstrating that the presence of an acetyl substituent on the 6-hydroxy group does not have a relevant influence on the peak potential of the wave resulting from oxidation of the 3-phenolic group.

Growth pressure dependence of Cu2ZnSnSe4 properties

In this work, we show a set of growth conditions, for the two step process, with which the growth of CZTSe is successful and reproducible. The properties of the best CTZSe thin films grown by this method were examined by SEM/EDS, XRD, Raman scattering, AFM/EFM, transmittance and reflectance measurements, photoluminescence (PL) measurements and hot point probe. A broad emission band was observed in the photoluminescence spectrum of the CZTSe thin film. The band gap energy was estimated to be around 1.05 eV at room temperature, using the transmittance and reflectance data, and CZTSe samples show p-type conductivity with the hot point probe. The different characterization techniques show that we could grow single phase CZTSe thin films with our optimized process conditions.

Risk of dependence associated with health, social support, and lifestyle

OBJECTIVE To analyze the prevalence of individuals at risk of dependence and its associated factors.METHODS The study was based on data from the Catalan Health Survey, Spain conducted in 2010 and 2011. Logistic regression models from a random sample of 3,842 individuals aged ≥ 15 years were used to classify individuals according to the state of their personal autonomy. Predictive models were proposed to identify indicators that helped distinguish dependent individuals from those at risk of dependence. Variables on health status, social support, and lifestyles were considered.RESULTS We found that 18.6% of the population presented a risk of dependence, especially after age 65. Compared with this group, individuals who reported dependence (11.0%) had difficulties performing activities of daily living and had to receive support to perform them. Habits such as smoking, excessive alcohol consumption, and being sedentary were associated with a higher probability of dependence, particularly for women.CONCLUSIONS Difficulties in carrying out activities of daily living precede the onset of dependence. Preserving personal autonomy and function without receiving support appear to be a preventive factor. Adopting an active and healthy lifestyle helps reduce the risk of dependence.

Long-term dependence in financial prices: evidence from the Belgian stock market returns

This article aims to contribute to the discussion of long-term dependence, focusing on the behavior of the main Belgian stock index. Non-parametric analyzes of the general characteristics of temporal frequency show that daily returns are non-ergodic and non-stationary. Therefore, we use the rescaled-range analysis (R/S) and the detrended fluctuation analysis (DFA), under the fractional Brownian motion approach, and we found slight evidence of long-term dependence. These results refute the random walk hypothesis with i.i.d. increments, which is the basis of the EMH in its weak form, and call into question some theoretical modeling of asset pricing. Other more localized complementary study, to identify the evolution of the degree of dependence over time windows, showed that the index has become less persistent from 2010. This may mean a maturing market by the extension of the effects of current financial crisis.

Microglial clearance function: dependence on phenotypes

Dissertação para obtenção do Grau de Mestre em Genética Molecular e Biomedicina

Dependence of IVIM-DWI estimations on acquisition parameters

Dissertação para obtenção do Grau de Mestre em Engenharia Biomédica

Fossil fuel dependence and interfuel substitution in the electricity sector of Western European countries between 1990-2011

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Economics from the NOVA – School of Business and Economics

Association between the degree of physical impairment from leprosy and dependence in activities of daily living among the elderly in a health unit in the State of Minas Gerais

Introduction In addition to the common alterations and diseases inherent in the aging process, elderly persons with a history of leprosy are particularly vulnerable to dependence because of disease-related impairments. Objective determine whether physical impairment from leprosy is associated with dependence among the elderly. Methods An analytical cross-sectional study of elderly individuals with a history of leprosy and no signs of cognitive impairment was conducted using a database from a former leprosy colony-hospital. The patients were evaluated for dependence in the basic activities of daily living (BADL) and instrumental activities of daily living (IADL), respectively) and subjected to standard leprosy physical disability grading. Subsequently, descriptive and univariate analyses were conducted, the latter using Pearson's chi-squared test. Results A total of 186 elderly persons were included in the study. Of these individuals, 53.8% were women, 49.5% were older than 75 years of age, 93% had four or less years of formal education, 24.2% lived in an institution for the long-term care of the elderly (ILTC), and 18.3% had lower limb amputations. Among those evaluated, 79.8% had visible physical impairments from leprosy (grade 2), 83.3% were independent in BADL, and 10.2% were independent in IADL. There was a higher impairment grade among those patients who were IADL dependent (p=0.038). Conclusion s: The leprosy physical impairment grade is associated with dependence for IADL, creating the need for greater social support and systematic monitoring by a multidisciplinary team. The results highlight the importance of early diagnosis and treatment of leprosy to prevent physical impairment and dependence in later years.

Centrality and rapidity dependence of inclusive jet production in sNN=5.02 TeV proton-lead collisions with the ATLAS detector

Measurements of the centrality and rapidity dependence of inclusive jet production in sNN−−−√=5.02 TeV proton--lead (p+Pb) collisions and the jet cross-section in s√=2.76 TeV proton--proton collisions are presented. These quantities are measured in datasets corresponding to an integrated luminosity of 27.8 nb−1 and 4.0 pb−1, respectively, recorded with the ATLAS detector at the Large Hadron Collider in 2013. The p+Pb collision centrality was characterised using the total transverse energy measured in the pseudorapidity interval −4.9<η<−3.2 in the direction of the lead beam. Results are presented for the double-differential per-collision yields as a function of jet rapidity and transverse momentum (pT) for minimum-bias and centrality-selected p+Pb collisions, and are compared to the jet rate from the geometric expectation. The total jet yield in minimum-bias events is slightly enhanced above the expectation in a pT-dependent manner but is consistent with the expectation within uncertainties. The ratios of jet spectra from different centrality selections show a strong modification of jet production at all pT at forward rapidities and for large pT at mid-rapidity, which manifests as a suppression of the jet yield in central events and an enhancement in peripheral events. These effects imply that the factorisation between hard and soft processes is violated at an unexpected level in proton--nucleus collisions. Furthermore, the modifications at forward rapidities are found to be a function of the total jet energy only, implying that the violations may have a simple dependence on the hard parton--parton kinematics.

On the temperature dependence of the absorption cross section for black holes in string theory

We study the low frequency absorption cross section of spherically symmetric nonextremal d-dimensional black holes. In the presence of α′ corrections, this quantity must have an explicit dependence on the Hawking temperature of the form 1/TH. This property of the low frequency absorption cross section is shared by the D1-D5 system from type IIB superstring theory already at the classical level, without α′ corrections. We apply our formula to the simplest example, the classical d-dimensional Reissner-Nordstr¨om solution, checking that the obtained formula for the cross section has a smooth extremal limit. We also apply it for a d-dimensional Tangherlini-like solution with α′3 corrections.