975 resultados para Problems faced in the classical approach


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The importance of developing effective assays to diagnose, monitor and evaluate human lymphatic filariasis has been emphasized by the World Health Organization. Presently, few immunodiagnostics are available for filarial monitoring programmes. The Wuchereria bancrofti (Wb) SXP-1 parasite protein, with 84% homology to Brugia malayi (Bm) SXP-1, was found to be highly immunogenic. WbSXP-1 is one among the diagnostic candidate molecules that were used for developing a rapid-antibody-flow-through diagnostic kit for filariasis. Studies were initiated with the aim of developing monoclonal antibodies against recombinant WbSXP-1 and prospective applications for the detection of both circulating Wb and Bm antigens in serum samples from infected individuals. The monoclones 1A6C2 of subclass IgG1k, and 2A12F8 of class IgM, specifically detected Wb and Bm microfilaria isolated from patients and did not show cross-reactivity with other filarial recombinant antigens. We anticipate that this work will address the problems faced in the rapid diagnosis of human lymphatic filariasis in endemic areas in developing countries.

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The intent of this study is to provide formal apparatus which facilitates the investigation of problems in the methodology of science. The introduction contains several examples of such problems and motivates the subsequent formalism.

A general definition of a formal language is presented, and this definition is used to characterize an individual’s view of the world around him. A notion of empirical observation is developed which is independent of language. The interplay of formal language and observation is taken as the central theme. The process of science is conceived as the finding of that formal language that best expresses the available experimental evidence.

To characterize the manner in which a formal language imposes structure on its universe of discourse, the fundamental concepts of elements and states of a formal language are introduced. Using these, the notion of a basis for a formal language is developed as a collection of minimal states distinguishable within the language. The relation of these concepts to those of model theory is discussed.

An a priori probability defined on sets of observations is postulated as a reflection of an individual’s ontology. This probability, in conjunction with a formal language and a basis for that language, induces a subjective probability describing an individual’s conceptual view of admissible configurations of the universe. As a function of this subjective probability, and consequently of language, a measure of the informativeness of empirical observations is introduced and is shown to be intuitively plausible – particularly in the case of scientific experimentation.

The developed formalism is then systematically applied to the general problems presented in the introduction. The relationship of scientific theories to empirical observations is discussed and the need for certain tacit, unstatable knowledge is shown to be necessary to fully comprehend the meaning of realistic theories. The idea that many common concepts can be specified only by drawing on knowledge obtained from an infinite number of observations is presented, and the problems of reductionism are examined in this context.

A definition of when one formal language can be considered to be more expressive than another is presented, and the change in the informativeness of an observation as language changes is investigated. In this regard it is shown that the information inherent in an observation may decrease for a more expressive language.

The general problem of induction and its relation to the scientific method are discussed. Two hypotheses concerning an individual’s selection of an optimal language for a particular domain of discourse are presented and specific examples from the introduction are examined.

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Sustainable water use is seriously compromised in the North China Plain (NCP) due to the huge water requirements of agriculture, the largest use of water resources. An integrated approach which combines the ecosystem model with emergy analysis is presented to determine the optimum quantity of irrigation for sustainable development in irrigated cropping systems. Since the traditional emergy method pays little attention to the dynamic interaction among components of the ecological system and dynamic emergy accounting is in its infancy, it is hard to evaluate the cropping system in hypothetical situations or in response to specific changes. In order to solve this problem, an ecosystem model (Vegetation Interface Processes (VIP) model) is introduced for emergy analysis to describe the production processes. Some raw data, collected by investigating or observing in conventional emergy analysis, may be calculated by the VIP model in the new approach. To demonstrate the advantage of this new approach, we use it to assess the wheat-maize rotation cropping system at different irrigation levels and derive the optimum quantity of irrigation according to the index of ecosystem sustainable development in NCP. The results show, the optimum quantity of irrigation in this region should be 240-330 mm per year in the wheat system and no irrigation in the maize system, because with this quantity of irrigation the rotation crop system reveals: best efficiency in energy transformation (transformity = 6.05E + 4 sej/J); highest sustainability (renewability = 25%); lowest environmental impact (environmental loading ratio = 3.5) and the greatest sustainability index (Emergy Sustainability Index = 0.47) compared with the system in other irrigation amounts. This study demonstrates that application of the new approach is broader than the conventional emergy analysis and the new approach is helpful in optimizing resources allocation, resource-savings and maintaining agricultural sustainability.

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Two ectoparasitic ciliates, Trichodina fugu Imai et al., 1997 and T. jadranica Raabe, 1958, found on the gills and skin of the maricultured tiger puffer Takifugu rubripes on the China coast of the Yellow Sea, were studied using the dry silver nitrate method. Trichodina fugu is distinguished by its almost rod-shaped denticle blades. Trichodina jadranica is usually described as a small trichodinid with a clear central circle in the adhesive disc and with a low number of denticles. However, the data available suggest that the species is highly variable in morphometry and the Chinese population represents the largest in body size and denticle dimensions found to date. Based on the revision of T. jadranica, two major morphotypes, each represented by several populations are classified, differing in the shape of the blades, viz., distinctly curved and sickle-shaped with pointed distal ends (as in the classical T. jadranica) vs. less curved and more or less rectangle-like with rounded distal ends (as in T. domerguei gobii). Trichodina domerguei gobii Raabe,.1959, which was synonymised with T. jadranica, is thus elevated to species rank. Furthermore, Trichodina jadranica noblei Lom, 1970 has straight and stout blades with broadly rounded distal ends and is raised to species rank: T noblei Lom, 1970. Trichodina jadranica sensu Xu et al., 1995 shows high similarities in denticle shape and dimensions as well as the central granule pattern with T chlamydis Xu et al., 1999. Thus, it is synonymised with the latter species.

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Among the many issues that were raised in the White Book on National Security of the Republic of Poland (WBNSRP), there were also those related to the functioning of a Common Security and Defence Policy (CSDP). Its importance for the security of Poland was indicated, as well as the need on the part of EU Member States to broaden collaboration in the sphere of security and defence. The key problems occurring in the context of CSDP were also emphasised and their causes indicated. The aim of the article is to present the factors responsible for the weakening of CSDP effectiveness, ones taken into account in the White Book, and subsequently to present a Framework for their analysis in the light of further scholarship.

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The effect of fluctuations in the classical control parameters on the Berry phase of a spin 1/2 interacting with an adiabatically cyclically varying magnetic field is analyzed. It is explicitly shown that in the adiabatic limit dephasing is due to fluctuations of the dynamical phase.

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Purpose The aim of this work was to examine, for amorphous solid dispersions, how the thermal analysis method selected impacts on the construction of thermodynamic phase diagrams, and to assess the predictive value of such phase diagrams in the selection of optimal, physically stable API-polymer compositions. Methods Thermodynamic phase diagrams for two API/polymer systems (naproxen/HPMC AS LF and naproxen/Kollidon 17 PF) were constructed from data collected using two different thermal analysis methods. The “dynamic” method involved heating the physical mixture at a rate of 1 &[deg]C/minute. In the "static" approach, samples were held at a temperature above the polymer Tg for prolonged periods, prior to scanning at 10 &[deg]C/minute. Subsequent to construction of phase diagrams, solid dispersions consisting of API-polymer compositions representative of different zones in the phase diagrams were spray dried and characterised using DSC, pXRD, TGA, FTIR, DVS and SEM. The stability of these systems was investigated under the following conditions: 25 &[deg]C, desiccated; 25 &[deg]C, 60 % RH; 40 &[deg]C, desiccated; 40 &[deg]C, 60 % RH. Results Endset depression occurred with increasing polymer volume fraction (Figure 1a). In conjunction with this data, Flory-Huggins and Gordon-Taylor theory were applied to construct thermodynamic phase diagrams (Figure 1b). The Flory-Huggins interaction parameter (&[chi]) for naproxen and HPMC AS LF was + 0.80 and + 0.72, for the dynamic and static methods respectively. For naproxen and Kollidon 17 PF, the dynamic data resulted in an interaction parameter of - 1.1 and the isothermal data produced a value of - 2.2. For both systems, the API appeared to be less soluble in the polymer when the dynamic approach was used. Stability studies of spray dried solid dispersions could be used as a means of validating the thermodynamic phase diagrams. Conclusion The thermal analysis method used to collate data has a deterministic effect on the phase diagram produced. This effect should be considered when constructing thermodynamic phase diagrams, as they can be a useful tool in predicting the stability of amorphous solid dispersions.

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The present work deals with the development of robust numerical tools for Isogeometric Analysis suitable for problems of solid mechanics in the nonlinear regime. To that end, a new solid-shell element, based on the Assumed Natural Strain method, is proposed for the analysis of thin shell-like structures. The formulation is extensively validated using a set of well-known benchmark problems available in the literature, in both linear and nonlinear (geometric and material) regimes. It is also proposed an alternative formulation which is focused on the alleviation of the volumetric locking pathology in linear elastic problems. In addition, an introductory study in the field of contact mechanics, in the context of Isogeometric Analysis, is also presented, with special focus on the implementation of a the Point-to-Segment algorithm. All the methodologies presented in the current work were implemented in a in-house code, together with several pre- and post-processing tools. In addition, user subroutines for the commercial software Abaqus were also implemented.

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Volatile organic compounds are a common source of groundwater contamination that can be easily removed by air stripping in columns with random packing and using a counter-current flow between the phases. This work proposes a new methodology for the column design for any particular type of packing and contaminant avoiding the necessity of a pre-defined diameter used in the classical approach. It also renders unnecessary the employment of the graphical Eckert generalized correlation for pressure drop estimates. The hydraulic features are previously chosen as a project criterion and only afterwards the mass transfer phenomena are incorporated, in opposition to conventional approach. The design procedure was translated into a convenient algorithm using C++ as programming language. A column was built in order to test the models used either in the design or in the simulation of the column performance. The experiments were fulfilled using a solution of chloroform in distilled water. Another model was built to simulate the operational performance of the column, both in steady state and in transient conditions. It consists in a system of two partial non linear differential equations (distributed parameters). Nevertheless, when flows are steady, the system became linear, although there is not an evident solution in analytical terms. In steady state the resulting system of ODE can be solved, allowing for the calculation of the concentration profile in both phases inside the column. In transient state the system of PDE was numerically solved by finite differences, after a previous linearization.

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Susan Nixon died in 1881 following a surgical error. Her surgeon, Dr W. E. Warren, excised a normal 7-month gravid uterus under the misapprehension that he was removing a tubular pregnancy. It is believed that Mrs Nixon was the first woman in Australia to have an abdominal hysterectomy and the second to have a live Caesarean section. The surgical misadventure that resulted in Mrs Nixon's death became a public scandal, which gained currency through both parliamentary debate and the popular press.

The purpose of referring to this case is to explore the mechanisms of accountability that surgeons faced in the 1880s − a decade of rapid change in the practice of surgery. The response of late nineteenth century society to surgical error and the resultant reaction of the medical profession have resonances that are relevant to surgeons practising today.


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Many scholars of Byzantine architecture have theorised about the reasons for church form and structure, with most relating them to sources in pagan architecture or local traditional construction methods (Krautheimer, Crowfoot, Ward-Perkins, Mango and Hill); to aspects of provincialism, regional independence or location peripheral to empire (Megaw, Delvoye, Wharton), or to environmental constraints such as frequent earthquakes (Curcic). But just as the wording of the various creeds and ecumenical statements responded to aspects of contemporary non-orthodox beliefs or "heresies", so did the theological debate inform the liturgical practices and consequently church planning. It could be expected that these responses would also be reflected in the architectural approach to form and symbolism. Thus a contextual typological framework is proposed, based on the association of different architectural approaches to church planning and form in the 4th to the 6th centuries with the contemporary doctrinal disputes over the true nature of Christ.

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Abstract
A current doctrine in the dynamometric approach to determine lateralization of hand function states that in 10% of cases, the non-dominant hand will be stronger than the dominant hand. In this study, a novel MRI based modelling approach was applied to the first dorsal introsseus muscle (FDI), to determine whether the 10% rule may be applied to the FDI and may be partially explained by the arrangement of the anatomical components of the FDI.

Methods
Initially the force generated by the thumb segment during an isometric pushing task in the horizontal plane was measured from 25 strongly right-handed young males. Nine of these participants then had structural magnetic resonance imaging (sMRI) of the thumb and index osseous compartment. A modelling technique was developed to extract the muscle data and quantify the muscle line of action onto to the first metacarpal bone segment in order to quantify the muscle force at the point of momentary rotation – equilibrium.

Results
Eight of 25 subjects exhibited stronger force from the left hand. Six out of nine subjects from the MRI possessed significantly greater angles of attachment of the index osseous compartment on the left (non-dominant) hand. These six subjects also generated greater maximal isometric forces from the FDI of the left side. There was a significantly greater muscle volume for the right FDI muscle as compared to the left as measured from the reconstructed MRI slice data.

Conclusions
The calculated force produced by the muscle is related to the angle of attachment of the muscle to bone in the index osseous compartment. The MRI findings indicate that the 10% rule may be anatomically and biomechanically explained.

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The main objective of this article is to test the hypothesis that utility preferences that incorporate asymmetric reactions between gains and losses generate better results than the classic Von Neumann-Morgenstern utility functions in the Brazilian market. The asymmetric behavior can be computed through the introduction of a disappointment (or loss) aversion coefficient in the classical expected utility function, which increases the impact of losses against gains. The results generated by both traditional and loss aversion utility functions are compared with real data from the Brazilian market regarding stock market participation in the investment portfolio of pension funds and individual investors.

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The pion electromagnetic form factor is calculated with a light-front quark model. The plus and minus components of the electromagnetic current are used to calculate the electromagnetic form factor in the the Breit frame with two models for the q (q) over bar vertex. The light-front constituent quark model describes very well the hadronic wave functions for pseudo-scalar and vector particles. Symmetry problems arising in the light-front approcah are solved by the pole dislocation method. The results are compared with new experimental data and with other quark models.

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The time evolution of the matter produced in high energy heavy-ion collisions seems to be well described by relativistic viscous hydrodynamics. In addition to the hydrodynamic degrees of freedom related to energy-momentum conservation, degrees of freedom associated with order parameters of broken continuous symmetries must be considered because they are all coupled to each other. of particular interest is the coupling of degrees of freedom associated with the chiral symmetry of QCD. Quantum and thermal fluctuations of the chiral fields act as noise sources in the classical equations of motion, turning them into stochastic differential equations in the form of Ginzburg-Landau-Langevin (GLL) equations. Analytic solutions of GLL equations are attainable only in very special circumstances and extensive numerical simulations are necessary, usually by discretizing the equations on a spatial lattice. However, a not much appreciated issue in the numerical simulations of GLL equations is that ultraviolet divergences in the form of lattice-spacing dependence plague the solutions. The divergences are related to the well-known Rayleigh-Jeans catastrophe in classical field theory. In the present communication we present a systematic lattice renormalization method to control the catastrophe. We discuss the implementation of the method for a GLL equation derived in the context of a model for the QCD chiral phase transition and consider the nonequilibrium evolution of the chiral condensate during the hydrodynamic flow of the quark-gluon plasma.