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Search Results: 1 - 10 of 259210 matches for " Jo?o F.;Martins "
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Dating the Cart-Ruts of Terceira Island, Azores, Portugal  [PDF]
Félix Rodrigues, Joo Madruga, Nuno Martins, Fábio Cardoso
Archaeological Discovery (AD) , 2018, DOI: 10.4236/ad.2018.64014
Abstract: Unlike other cart ruts found elsewhere in the world, the Azorean cart-ruts, engraved on volcanic stone, at the middle of the Atlantic, raise many questions: How old are they? Who created them? Were they made during a short or long time? These mysteriously enigmatic parallel grooves are noticed on the hard volcanic rock of the nine Azorean Islands in several locations. Recent scientific evidences have provided some support to the hypothesis of human presence in the Azores Islands before Portuguese settlement during the 15th century. Are the Azorean cart-ruts pre-Portuguese? Here we try to establish a chronology for the cart-ruts of Terceira Island, Azores, Portugal, using a historical approach, a geological approach and also a 14C dating approach, the last one obtained by dating a placic horizon found in the grooves of the cart-ruts named “Passage of the Beasts”, which indicates the presence of human activity in the island at least during the 11th century, or probably before. The date obtained is consistent with another date achieved through similar methods for a man-made basin in the same island and is also consistent with the historiographical records.
Trimetazidine and Cellular Response in Cardiopulmonary Bypass*  [PDF]
Gerez Fernandes Martins, Aristarco G. de Siqueira Filho, Joo Bosco de F. Santos, Claudio Roberto Cavalcanti Assun??o, Alberto Valência, Gerez Martins
World Journal of Cardiovascular Surgery (WJCS) , 2013, DOI: 10.4236/wjcs.2013.35035
Abstract: Background: Organic cellular inflammatory response constitutes a pathophysiological mechanism present in all Coronary Artery Bypass Graftings (CABGs). In this aspect, the organism brings forth its defenses through answers that involve cellular components. Objectives: To evaluate, in a randomized double-blind prospective study, controlled with placebo, the effects of trimetazidine (Tmz) on cellular response, analyzed through the variation of leukocytes, neutrophils and monocytes. Patients and Method: 30 patients were randomly selected to be studied, with no more than a mild ventricular dysfunction, and divided into two groups (Tmz and placebo) stratified by echocardiography and receiving medication/placebo in a 60 mg/day dose. The samples of leukocytes, neutrophils and monocytes were obtained in the pre-operatory day without medication, at surgery day with 12 to 15 days of medication/placebo, with 5 minutes after the aortic declamping, and within 12, 24 and 48 hours after surgery. Results: The leukocytes and neutrophils levels have decreased significantly in the treated group when compared to the control group, in all analyzed moments (p = 0.012; p = 0.005). Conclusions and Clinical Implications: Trimetazidine has proved to reduce significantly the levels of total leukocytes and neutrophils in patients submitted to CABG.
Physiologic Basis and Pathophysiologic Implications of the Diastolic Properties of the Cardiac Muscle
Jo o Ferreira-Martins,Adelino F. Leite-Moreira
Journal of Biomedicine and Biotechnology , 2010, DOI: 10.1155/2010/807084
Abstract: Although systole was for long considered the core of cardiac function, hemodynamic performance is evenly dependent on appropriate systolic and diastolic functions. The recognition that isolated diastolic dysfunction is the major culprit for approximately fifty percent of all heart failure cases imposes a deeper understanding of its underlying mechanisms so that better diagnostic and therapeutic strategies can be designed. Risk factors leading to diastolic dysfunction affect myocardial relaxation and/or its material properties by disrupting the homeostasis of cardiomyocytes as well as their relation with surrounding matrix and vascular structures. As a consequence, slower ventricular relaxation and higher myocardial stiffness may result in higher ventricular filling pressures and in the risk of hemodynamic decompensation. Thus, determining the mechanisms of diastolic function and their implications in the pathophysiology of heart failure with normal ejection fraction has become a prominent field in basic and clinical research.
Potencial da erva daninha Waltheria americana (Sterculiaceae) no manejo integrado de pragas e polinizadores: visitas de abelhas e vespas
Macedo, Joo F.;Martins, Rogério P.;
Anais da Sociedade Entomológica do Brasil , 1998, DOI: 10.1590/S0301-80591998000100004
Abstract: the potential of the weed waltheria americana for integrated management of pollinators and pests was evaluated by quantifying bee and wasp richness and amount of visitation to its flowers. observations were made in two patches of the weed at the campus of the universidade federal de minas gerais, belo horizonte, mg. production of flowers, visitor richness and frequency of visits were estimated by inspecting 20 plants in each patch every month. we recorded a total of 37 bee and 72 wasp species. there was a significant correlation between the number of species and number of visits of wasps with the number of flowers for one of the sites. a large proportion of the bee and wasp species recorded at each site were found only one month of the year, or only a single day. only two species of predatory wasp, ammophila gracilis lepeletier, 1845, and bicyrtes angulata smith, 1856, visited the weed during all 12 months of the study. augochloropsis callichroa cockcrell, 1900, was the most frequent bee, occurring during 9 months. waltheria americana is a very succesful colonizer of cultivated lands and disturbed habitats, and by virtue of the nectar supply it offers to a large variety of bees and wasps it can be suggested as an aid in integrated pollination and pest management programs.
A estrutura da guilda de abelhas e vespas visitantes florais de Waltheria americana L. (Sterculiaceae)
Macedo, Joo F.;Martins, Rogério P.;
Anais da Sociedade Entomológica do Brasil , 1999, DOI: 10.1590/S0301-80591999000400005
Abstract: the number of flowers produced by the weed waltheria americana l (sterculiaceae) and the number of flowering dicot species were quantified in two sites at the campus of the universidade federal de minas gerais, to evaluate their seasonal relative importance as a source of nectar and pollen to a guild of 72 species of wasps and 37 species of bees. differences between the average number of flowering dicot species between the dry and rainy seasons were found in only one of the sites. a significant difference in the number of flowers produced by w. americana between the two seasons was found in only one of the sites. only the number of wasps visiting w. americana varied between seasons. seasonal variation in guild composition was observed in one of the sites and only the bees showed a strong variation in species composition along the year. there was a positive correlation between the number of flowering dicot species and both the number of bee visits, and the number of flowers of w. americana. however, there were no differences between seasons in the average of visits. on the other hand, there was no correlation between the number of wasp visits to w. americana and either the number of flowers of w. americana or the number of other flowering dicot species in one site. on average, wasps visit w. americana more frequently in the rainy season than in the dry one in one of the sites, but the inverse occurred in the other site. the daily flower visitation of wasps and bees was most intense, and similar, between nine and 13 h. because w. americana flowers year round and is a source of nectar for bees and wasps, its management could be important to maintain the diversity of bees and wasps in disturbed areas or agroecosystems, thus supporting insects which may act as pollinators and biological control agents, respectively.
Os efeitos da desmaterializa??o das rela??es bancárias devido ao uso do Internet ?Banking? e do marketing relacional
Proen?a,Joo F.; Silva,Marta Martins;
Revista Portuguesa e Brasileira de Gest?o , 2008,
Abstract: the new technologies? evolution has introduced new business methods that allow companies to adapt to the emergent ways of interaction with clients. these innovations are particularly evident in banking. the present challenge in this sector is the dematerialization of customer relationships from the numerous new information and communication technologies available in the market, which allows clients to satisfy almost all their needs with minimum human intervention. this paper analyses the impact of the internet banking (ib) in relationships between the banks and their clients. the research was done in portugal and has identified three factors related with the use of ib which strengthen the relationship between the parts: the intensity of ib use, the diversity of access location sand the diversity of applications.
Os efeitos da desmaterializa o das rela es bancárias devido ao uso do Internet Banking e do marketing relacional Los efectos de la des materialización de las relaciones bancarias debido al uso del Internet Banking y del Marketing Relacional The dematerialisation effects on banking relationships due to the Internet and relationships marketing us
Joo F. Proen?a,Marta Martins Silva
Revista Portuguesa e Brasileira de Gest?o , 2008,
Abstract: A constante evolu o das novas tecnologias de informa o e comunica o introduz no mercado empresarial a necessidade de desenvolver métodos de gest o que permitam às empresas adaptar-se às formas emergentes de interac o com clientes. O caso do sector bancário é uma área que exemplifica essa situa o. A desmaterializa o das rela es resultante das inúmeras novas tecnologias disponíveis no mercado, entre as quais o Internet Banking (IB), permite a satisfa o de quase todas as necessidades do cliente com interven o humana mínima. Este trabalho analisa o impacto da utiliza o do IB na rela o entre os bancos e os seus clientes particulares. A investiga o foi realizada em Portugal e identifica três factores da utiliza o do IB que refor am a rela o entre as partes: a intensidade de uso do IB, a diversidade de locais de acesso e a diversidade de opera es realizadas via IB. La constante evolución de las nuevas tecnologías de la información y comunicación introduce en el mer-cado empresarial una necesidad de desarrollar nuevos métodos de gestión que permitan a las empresas adaptarse alas nuevas formas emergentes de interacción con sus clientes. El sector bancario es un sector que ejemplifica esa situación. La des materialización de las relaciones resultantes de las nuevas tecnologías disponibles en el mercado, entre las cuales se encuentra el Internet Banking permite la satisfacción de casi todas las necesidades del cliente con una intervención humana mínima. Este trabajo analiza el impacto en la utilización del Internet Banking en la relación entre los bancos y sus clientes particulares. La investigación fue realizada en Portugal e identifica tres factores en la utilización del Internet Banking que refuerzan la relación entre las partes: la intensidad del uso del Internet Banking, la diversidad de locales de acceso y la diversidad de operaciones realizadas vía Internet Banking. The new technologies’ evolution has introduced new business methods that allow companies to adapt to the emergent ways of interaction with clients. These innovations are particularly evident in banking. The present challenge in this sector is the dematerialization of customer relationships from the numerous new information and communication technologies available in the market, which allows clients to satisfy almost all their needs with minimum human intervention. This paper analyses the impact of the Internet Banking (IB) in relationships between the banks and their clients. The research was done in Portugal and has identified three factors related with the use of IB which stre
High-Speed Tracking with Kernelized Correlation Filters
Joo F. Henriques,Rui Caseiro,Pedro Martins,Jorge Batista
Computer Science , 2014, DOI: 10.1109/TPAMI.2014.2345390
Abstract: The core component of most modern trackers is a discriminative classifier, tasked with distinguishing between the target and the surrounding environment. To cope with natural image changes, this classifier is typically trained with translated and scaled sample patches. Such sets of samples are riddled with redundancies -- any overlapping pixels are constrained to be the same. Based on this simple observation, we propose an analytic model for datasets of thousands of translated patches. By showing that the resulting data matrix is circulant, we can diagonalize it with the Discrete Fourier Transform, reducing both storage and computation by several orders of magnitude. Interestingly, for linear regression our formulation is equivalent to a correlation filter, used by some of the fastest competitive trackers. For kernel regression, however, we derive a new Kernelized Correlation Filter (KCF), that unlike other kernel algorithms has the exact same complexity as its linear counterpart. Building on it, we also propose a fast multi-channel extension of linear correlation filters, via a linear kernel, which we call Dual Correlation Filter (DCF). Both KCF and DCF outperform top-ranking trackers such as Struck or TLD on a 50 videos benchmark, despite running at hundreds of frames-per-second, and being implemented in a few lines of code (Algorithm 1). To encourage further developments, our tracking framework was made open-source.
Differential Effects of Methyl-4-Phenylpyridinium Ion, Rotenone, and Paraquat on Differentiated SH-SY5Y Cells
Joo Barbosa Martins,Maria de Lourdes Bastos,Félix Carvalho,Joo Paulo Capela
Journal of Toxicology , 2013, DOI: 10.1155/2013/347312
Abstract:
Differential Effects of Methyl-4-Phenylpyridinium Ion, Rotenone, and Paraquat on Differentiated SH-SY5Y Cells
Joo Barbosa Martins,Maria de Lourdes Bastos,Félix Carvalho,Joo Paulo Capela
Journal of Toxicology , 2013, DOI: 10.1155/2013/347312
Abstract: Paraquat (PQ), a cationic nonselective bipyridyl herbicide, has been used as neurotoxicant to modulate Parkinson’s disease in laboratory settings. Other compounds like rotenone (ROT), a pesticide, and 1-methyl-4-phenylpyridinium ion (MPP+) have been widely used as neurotoxicants. We compared the toxicity of these three neurotoxicants using differentiated dopaminergic SH-SY5Y human cells, aiming to elucidate their differential effects. PQ-induced neurotoxicity was shown to be concentration and time dependent, being mitochondrial dysfunction followed by neuronal death. On the other hand, cells exposure to MPP+ induced mitochondrial dysfunction, but not cellular lyses. Meanwhile, ROT promoted both mitochondrial dysfunction and neuronal death, revealing a biphasic pattern. To further elucidate PQ neurotoxic mechanism, several protective agents were used. SH-SY5Y cells pretreatment with tiron (TIR) and 2-hydroxybenzoic acid sodium salt (NaSAL), both antioxidants, and Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME), a nitric oxide synthase inhibitor, partially protected against PQ-induced cell injury. Additionally, 1-(2-[bis(4-fluorophenyl)methoxy]ethyl)-4-(3-phenyl-propyl)piperazine (GBR 12909), a dopamine transporter inhibitor, and cycloheximide (CHX), a protein synthesis inhibitor, also partially protected against PQ-induced cell injury. In conclusion, we demonstrated that PQ, MPP+, and ROT exerted differential toxic effects on dopaminergic cells. PQ neurotoxicity occurred through exacerbated oxidative stress, with involvement of uptake through the dopamine transporter and protein synthesis. 1. Introduction Parkinson’s disease (PD) is considered the second most common neurodegenerative disorder worldwide, affecting 0.5 to 1% of the population aged between 65 and 69 years and 1 to 3% of the population over 80 years [1]. PD develops from a loss of nigrostriatal neuromelanin-containing dopaminergic neurons, whose cell bodies lay in the substantia nigra pars compacta (SNpc) [2]. This nigrostriatal pathway is essential for a normal motor function and movement control. PD is thought to have a multifactorial etiology, frequently including genetic and environmental factors [2, 3]. Several neurotoxic chemicals to dopaminergic neurons leading to PD-like symptoms have been used to study this disease. The synthetic compounds 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and 1-methyl-4-phenyl-4-propionoxy-piperidine (MPPP) were the first to be associated with PD symptoms, as described by Langston and Ballard [4]. MPTP enters the blood-brain barrier and is
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