33 resultados para Neumann problem
Resumo:
The tick-bird relationship of 56 specimens of birds (Passeriformes and Columbiformes) collected in the city of Curitiba, State of Paraná, between 1990 and 1995, among which 102 specimens of Ixodes (Multidentatus) auritulus were found and analyzed. New host records were also produced including the first report of I. auritulus on a Columbiformes bird in Brazil.
Resumo:
Variation between aeropile numbers of the right and left peritrematic plate in male and female Anocentor nitens (Neumann, 1897) is reported from a site in Brazil. From January to December 1998, 146 males and 247 females of A. nitens were recovered from Equus caballus L. in Silva Jardim District, State of Rio de Janeiro. Asymmetry of numbers of aeropiles between right and left plates occurred in 83.6% of the males and 82.2% of the females. Differences in the number of aeropiles between the sexes were not significant. Quantitative variation of aeropiles was correlated to the period of recovery, with significant asymmetry detected in August-September and November-December, mainly in males. Results suggest an adaptation, especially in the male ticks, that expresses itself as greater variation in the number of aeropiles in some periods of the year.
Resumo:
Chagas disease or American trypanosomiasis is, together with geohelminths, the neglected disease that causes more loss of years of healthy life due to disability in Latin America. Chagas disease, as determined by the factors and determinants, shows that different contexts require different actions, preventing new cases or reducing the burden of disease. Control strategies must combine two general courses of action including prevention of transmission to prevent the occurrence of new cases (these measures are cost effective), as well as opportune diagnosis and treatment of infected individuals in order to prevent the clinical evolution of the disease and to allow them to recuperate their health. All actions should be implemented as fully as possible and with an integrated way, to maximise the impact. Chagas disease cannot be eradicated due because of the demonstrated existence of infected wild triatomines in permanent contact with domestic cycles and it contributes to the occurrence of at least few new cases. However, it is possible to interrupt the transmission ofTrypanosoma cruziin a large territory and to eliminate Chagas disease as a public health problem with a dramatic reduction of burden of the disease.
Resumo:
Some people cannot buy products without first touching them, believing that doing so will create more assurance and information and reduce uncertainty. The international consumer marketing literature suggests an instrument to measure consumers' necessity for pohysical contact, called Need for Touch (NFT). This paper analyzes whether the Need for Touch structure is empirically consistent. Based on a literature review, we suggest six hypotheses in order to assess the nomological, convergent, and discriminant validity of the phenomenon. Departing from these, data supported four assumptions in the predicted direction. Need for Touch was associated with Need for Input and with Need for Cognition. Need for Touch was not associated with traditional marketing channels. The results also showed the dual characterization of Need for Touch as a bi-dimensional construct. The moderator effect indicated that when the consumer has a higher (vs. lower) Need for Touch autotelic score, the experiential motivation for shopping played a more (vs. less) important role in impulsive motivation. Our Study 3 supports the NFT structure and shows new associations with the need for unique products and dependent decisions.
Resumo:
This study aimed at analyzing nipple trauma resulted from breastfeeding based on dermatological approach. Two integrative reviews of literature were conducted, the first related to definitions, classification and evaluation methods of nipple trauma and another about validation studies related to this theme. In the first part were included 20 studies and only one third defined nipple trauma, more than half did not defined the nipple’s injuries reported, and each author showed a particular way to assess the injuries, without consensus. In the second integrative review, no validation study or algorithm related to nipple trauma resulted from breastfeeding was found. This fact demonstrated that the nipple’s injuries mentioned in the first review did not go through validation studies, justifying the lack of consensus identified as far as definition, classification and assessment methods of nipple trauma.
Resumo:
A partir de teleógina de Amblyomma nodosum Neumann, 1899, removida de Tamandua tetradactyla (Linnaeus, 1758) foram obtidas posturas que originaram larvas, em condições de laboratório. Um total de 219 larvas foi examinado em microscopia de luz, com objetiva de imersão e microscopia de confocal com varredura a laser. Buscou-se analisar a variação do número das cerdas internas dos lados direito e esquerdo, no fundo da cápsula do Órgão de Haller, com intuito de utilizá-las como um parâmetro quetotáxico na diagnose específica. A média do número de cerdas foi 5,06±0, 71, com valores limites da amplitude de 4-11.
Resumo:
A neural network procedure to solve inverse chemical kinetic problems is discussed in this work. Rate constants are calculated from the product concentration of an irreversible consecutive reaction: the hydrogenation of Citral molecule, a process with industrial interest. Simulated and experimental data are considered. Errors in the simulated data, up to 7% in the concentrations, were assumed to investigate the robustness of the inverse procedure. Also, the proposed method is compared with two common methods in nonlinear analysis; the Simplex and Levenberg-Marquardt approaches. In all situations investigated, the neural network approach was numerically stable and robust with respect to deviations in the initial conditions or experimental noises.
Resumo:
Methane combustion was studied by the Westbrook and Dryer model. This well-established simplified mechanism is very useful in combustion science, for computational effort can be notably reduced. In the inversion procedure to be studied, rate constants are obtained from [CO] concentration data. However, when inherent experimental errors in chemical concentrations are considered, an ill-conditioned inverse problem must be solved for which appropriate mathematical algorithms are needed. A recurrent neural network was chosen due to its numerical stability and robustness. The proposed methodology was compared against Simplex and Levenberg-Marquardt, the most used methods for optimization problems.
Resumo:
If the mental can affect, or be affected by, the physical, then the mental must itself be physical. Otherwise the physical world would not be explanatorily closed. But it is closed. There are reasons to hold that materialism (in both its reductive and non-reductive varieties) is false. So how are we to explain the apparent responsiveness of the physical to the mental and vice versa? The only possible solution seems to be this: physical objects are really projections or isomorphs of objects whose essential properties are mental. (A slightly less accurate way of putting this would be to say: the constitutive - i.e. the non-structural and non-phenomenal - properties of physical objects are mental, i.e. are such as we are used to encountering only in "introspection".) The chair, qua thing that I can know through sense perception, and through hypotheses based strictly thereupon, is a kind of shadow of an object that is exactly like it, except that this other objects essential properties are mental. This line of thought, though radically counterintuitive, explains the apparent responsiveness of the mental to the physical, and vice versa, without being open to any of the criticisms to which materialism, dualistic interaction ism, and epiphenomenalism are open.
Resumo:
The prevailing undergraduate medical training process still favors disconnection and professional distancing from social needs. The Brazilian Ministries of Education and Health, through the National Curriculum Guidelines, the Incentives Program for Changes in the Medical Curriculum (PROMED), and the National Program for Reorientation of Professional Training in Health (PRO-SAÚDE), promoted the stimulus for an effective connection between medical institutions and the Unified National Health System (SUS). In accordance to the new paradigm for medical training, the Centro Universitário Serra dos Órgãos (UNIFESO) established a teaching plan in 2005 using active methodologies, specifically problem-based learning (PBL). Research was conducted through semi-structured interviews with third-year undergraduate students at the UNIFESO Medical School. The results were categorized as proposed by Bardin's thematic analysis, with the purpose of verifying the students' impressions of the new curriculum. Active methodologies proved to be well-accepted by students, who defined them as exciting and inclusive of theory and practice in medical education.
Resumo:
In this paper I am concerned with the problem of applying the notion of rigidity to general terms. In Naming and Necessity, Kripke has clearly suggested that we should include some general terms among the rigid ones, namely, those common nouns semantically correlated with natural substances, species and phenomena, in general, natural kinds -'water', 'tiger', 'heat'- and some adjectives -'red', 'hot', 'loud'. However, the notion of rigidity has been defined for singular terms; after all, the notion that Kripke has provided us with is the notion of a rigid designator. But general terms do not designate single individuals: rather, they apply to many of them. In sum, the original concept of rigidity cannot be straightforwardly applied to general terms: it has to be somehow redefined in order to make it cover them. As is known, two main positions have been put forward to accomplish that task: the identity of designation conception, according to which a rigid general term is one that designates the same property or kind in all possible worlds, and the essentialist conception, which conceives of a rigid general term as an essentialist one, namely, a term that expresses an essential property of an object. My purpose in the present paper is to defend a particular version of the identity of designation conception: on the proposed approach, a rigid general term will be one that expresses the same property in all possible worlds and names the property it expresses. In my opinion, the position can be established on the basis of an inference to the best explanation of our intuitive interpretation and evaluation, relative to counterfactual circumstances, of statements containing different kinds of general terms, which is strictly analogous to our intuitive interpretation and evaluation, relative to such circumstances, of statements containing different kinds of singular ones. I will argue that it is possible to offer a new solution to the trivialization problem that is thought to threaten all versions of the identity of designation conception of rigidity. Finally, I will also sketch a solution to the so-called 'over-generalization and under-generalization problems', both closely related to the above-mentioned one.
Resumo:
This work presents a formulation of the contact with friction between elastic bodies. This is a non linear problem due to unilateral constraints (inter-penetration of bodies) and friction. The solution of this problem can be found using optimization concepts, modelling the problem as a constrained minimization problem. The Finite Element Method is used to construct approximation spaces. The minimization problem has the total potential energy of the elastic bodies as the objective function, the non-inter-penetration conditions are represented by inequality constraints, and equality constraints are used to deal with the friction. Due to the presence of two friction conditions (stick and slip), specific equality constraints are present or not according to the current condition. Since the Coulomb friction condition depends on the normal and tangential contact stresses related to the constraints of the problem, it is devised a conditional dependent constrained minimization problem. An Augmented Lagrangian Method for constrained minimization is employed to solve this problem. This method, when applied to a contact problem, presents Lagrange Multipliers which have the physical meaning of contact forces. This fact allows to check the friction condition at each iteration. These concepts make possible to devise a computational scheme which lead to good numerical results.
Resumo:
This paper deals with the use of the conjugate gradient method of function estimation for the simultaneous identification of two unknown boundary heat fluxes in parallel plate channels. The fluid flow is assumed to be laminar and hydrodynamically developed. Temperature measurements taken inside the channel are used in the inverse analysis. The accuracy of the present solution approach is examined by using simulated measurements containing random errors, for strict cases involving functional forms with discontinuities and sharp-corners for the unknown functions. Three different types of inverse problems are addressed in the paper, involving the estimation of: (i) Spatially dependent heat fluxes; (ii) Time-dependent heat fluxes; and (iii) Time and spatially dependent heat fluxes.