15 resultados para Theory of electronic transport scattering mechanisms
em Scielo Saúde Pública - SP
Resumo:
The importance of interaction between Operations Management (OM) and Human Behavior has been recently re-addressed. This paper introduced the Reasoned Action Theory suggested by Froehle and Roth (2004) to analyze Operational Capabilities exploring the suitability of this model in the context of OM. It also seeks to discuss the behavioral aspects of operational capabilities from the perspective of organizational routines. This theory was operationalized using Fishbein and Ajzen (F/A) behavioral model and a multi-case strategy was employed to analyze the Continuous Improvement (CI) capability. The results posit that the model explains partially the CI behavior in an operational context and some contingency variables might influence the general relations among the variables involved in the F/A model. Thus intention might not be the determinant variable of behavior in this context.
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Theory building is one of the most crucial challenges faced by basic, clinical and population research, which form the scientific foundations of health practices in contemporary societies. The objective of the study is to propose a Unified Theory of Health-Disease as a conceptual tool for modeling health-disease-care in the light of complexity approaches. With this aim, the epistemological basis of theoretical work in the health field and concepts related to complexity theory as concerned to health problems are discussed. Secondly, the concepts of model-object, multi-planes of occurrence, modes of health and disease-illness-sickness complex are introduced and integrated into a unified theoretical framework. Finally, in the light of recent epistemological developments, the concept of Health-Disease-Care Integrals is updated as a complex reference object fit for modeling health-related processes and phenomena.
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This article presents a systematic framework for modeling several classes of illness-sickness-disease named as Holopathogenesis. Holopathogenesis is defined as processes of over-determination of diseases and related conditions taken as a whole, comprising selected facets of the complex object Health. First, a conceptual background of Holopathogenesis is presented as a series of significant interfaces (biomolecular-immunological, physiopathological-clinical, epidemiological-ecosocial). Second, propositions derived from Holopathogenesis are introduced in order to allow drawing the disease-illness-sickness complex as a hierarchical network of networks. Third, a formalization of intra- and inter-level correspondences, over-determination processes, effects and links of Holopathogenesis models is proposed. Finally, the Holopathogenesis frame is evaluated as a comprehensive theoretical pathology taken as a preliminary step towards a unified theory of health-disease.
Resumo:
ABSTRACT Heavy metals contained in electronic waste, if discarded improperly, can become bioavailable after vermicomposting, posing a risk to the environment. Small-scale vermicomposting experiments were carried out with printed circuit boards (PCBs) to investigate the migration of heavy metals (Cu, Pb, Zn, Ni, and Sn) to the final compost, as well as the mobility and bioavailability of these metals. High total levels of Pb, Sn and Cu in samples of manure with electronic waste (MEW) and vegetables with electronic waste (VEW) were detected. Based on the initial metal levels in the PCBs and their concentration in the resulting compost, the order of migration of these metals to the MEW and VEW samples was Sn (23.1 %)>Pb (18.4 %)>Ni (4.63 %)>Zn (0.46 %)>Cu (0.14 %) and Sn (24.3 %)>Pb (23.6 %)>Ni (11.33 %)>Zn (1.76 %)>Cu (0.60 %), respectively. Mobility and bioavailability of these metals in the compost were evaluated by three-stage sequential extraction, where F1 was the exchangeable fraction, F2 the organic fraction and F3 the residual fraction. The bioavailability factor (BF) was calculated by the ratio of the sum of fractions F1 and F2 divided by the total sum of the fractions (F1 + F2 + F3). The highest bioavailability factor (BF = 0.92) was found for Pb, the heavy metal considered the greatest environmental concern in this study, indicating the high mobility and the possibility of becoming bioavailable of this metal.
Resumo:
Local conditions in the past often limited opportunities for scholarly exchange. But now these limits are gone and the global workplace has replaced them. It is important to react to these changes. Every academic department must now adopt new methods and rethink processes. Another is the intense national and international debate about open access to scholarly knowledge. The Open Access Initiative shows that a change is taking place in the communication process. This change is also important for service departments within research institutions. Libraries, computer centers and related units have to ask themselves how to react appropriately to the new conditions. What services must be changed or redeveloped, and in what quality and quantity should they be offered? This article focuses on changes in the scholarly publication process. It describes both technological changes and the changes needed in people's attitudes.
Resumo:
A simple, four-step method for better introducing undergraduate students to the fundamentals of molecular orbital (MO) theory of the polyatomic molecules H2O, NH3, BH3 and SiH4 using group theory is reported. These molecules serve to illustrate the concept of ligand group orbitals (LGOs) and subsequent construction of MO energy diagrams on the basis of molecular symmetry requirements.
Resumo:
The excitation energy transfer between chlorophylls in major and minor antenna complexes of photosystem II (PSII) was investigated using quantum Fourier transforms. These transforms have an important role in the efficiency of quantum algorithms of quantum computers. The equation 2n=N was used to make the connection between excitation energy transfers using quantum Fourier transform, where n is the number of qubits required for simulation of transfers and N is the number of chlorophylls in the antenna complexes.
Resumo:
Leibniz's conception of bodies seems to be a puzzling theory. Bodies are seen as aggregates of monads and as wellfounded phenomena. This has initiated controversy and unending discussions. The paper attempts to resolve the apparent inconsistencies by a new and formally spirited reconstruction of Leibniz's theory of monads and perception, on the one hand, and a (re-)formulation and precisation of his concept of preestablished harmony, on the other hand. Preestablished harmony is modelled basically as a covariation between the monadic and the ideal realm.
Resumo:
ABSTRACT When Hume, in the Treatise on Human Nature, began his examination of the relation of cause and effect, in particular, of the idea of necessary connection which is its essential constituent, he identified two preliminary questions that should guide his research: (1) For what reason we pronounce it necessary that every thing whose existence has a beginning should also have a cause and (2) Why we conclude that such particular causes must necessarily have such particular effects? (1.3.2, 14-15) Hume observes that our belief in these principles can result neither from an intuitive grasp of their truth nor from a reasoning that could establish them by demonstrative means. In particular, with respect to the first, Hume examines and rejects some arguments with which Locke, Hobbes and Clarke tried to demonstrate it, and suggests, by exclusion, that the belief that we place on it can only come from experience. Somewhat surprisingly, however, Hume does not proceed to show how that derivation of experience could be made, but proposes instead to move directly to an examination of the second principle, saying that, "perhaps, be found in the end, that the same answer will serve for both questions" (1.3.3, 9). Hume's answer to the second question is well known, but the first question is never answered in the rest of the Treatise, and it is even doubtful that it could be, which would explain why Hume has simply chosen to remove any mention of it when he recompiled his theses on causation in the Enquiry concerning Human Understanding. Given this situation, an interesting question that naturally arises is to investigate the relations of logical or conceptual implication between these two principles. Hume seems to have thought that an answer to (2) would also be sufficient to provide an answer to (1). Henry Allison, in his turn, argued (in Custom and Reason in Hume, p. 94-97) that the two questions are logically independent. My proposal here is to try to show that there is indeed a logical dependency between them, but the implication is, rather, from (1) to (2). If accepted, this result may be particularly interesting for an interpretation of the scope of the so-called "Kant's reply to Hume" in the Second Analogy of Experience, which is structured as a proof of the a priori character of (1), but whose implications for (2) remain controversial.
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In this paper, a systematic and quantitative view is presented for the application of the theory of constraints in manufacturing. This is done employing the operational research technique of mathematical programming. The potential of the theory of constraints in automated manufacturing is demonstrated.
Resumo:
This study was designed to evaluate the effect of different conditions of collection, transport and storage on the quality of blood samples from normal individuals in terms of the activity of the enzymes ß-glucuronidase, total hexosaminidase, hexosaminidase A, arylsulfatase A and ß-galactosidase. The enzyme activities were not affected by the different materials used for collection (plastic syringes or vacuum glass tubes). In the evaluation of different heparin concentrations (10% heparin, 5% heparin, and heparinized syringe) in the syringes, it was observed that higher doses resulted in an increase of at least 1-fold in the activities of ß-galactosidase, total hexosaminidase and hexosaminidase A in leukocytes, and ß-glucuronidase in plasma. When the effects of time and means of transportation were studied, samples that had been kept at room temperature showed higher deterioration with time (72 and 96 h) before processing, and in this case it was impossible to isolate leukocytes from most samples. Comparison of heparin and acid citrate-dextrose (ACD) as anticoagulants revealed that ß-glucuronidase and hexosaminidase activities in plasma reached levels near the lower normal limits when ACD was used. In conclusion, we observed that heparin should be used as the preferable anticoagulant when measuring these lysosomal enzyme activities, and we recommend that, when transport time is more than 24 h, samples should be shipped by air in a styrofoam box containing wet ice.
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This paper aims at shedding light on an obscure point in Kant's theory of the state. It discusses whether Kant's rational theory of the state recognises the fact that certain exceptional social situations, such as the extreme poverty of some parts of the population, could request institutional state support in order to guarantee the attainment of a minimum threshold of civil independence. It has three aims: 1) to show that Kant's Doctrine of Right can offer solutions for the complex relation between economics and politics in our present time; 2) to demonstrate the claim that Kant embraces a pragmatic standpoint when he tackles the social concerns of the state, and so to refute the idea that he argues for an abstract conception of politics; and 3) to suggest that a non-paternalistic theory of rights is not necessarily incompatible with the basic tenets of a welfare state.