The relation between the general maxim of causality and the principle of uniformity in hume's theory of knowledge

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.

The principle of autonomy in Brazil: one needs to discuss it ...

The principle of patient autonomy is a cornerstone of bioethics. According to this concept, patients should be given the power to make decisions related to their treatment. It is an important component of modern medical ethics, which has received much interest in current literature. However, the rate of participation of patients and their willingness to participate are variable according to the cultural, social and family environments in which they are inserted. The aim of this paper is to promote a brief descriptive review on autonomy, the preferences of patients and the use of informed consent as an instrument for the exercise of autonomy in literature, and to stress the lack of debate, as well as the pressing need for discussion of these current issues nationwide.

Encapsulated specialty oils commercialized in São Paulo state, Brazil: evaluation of identity (fatty acid profile) and compliance of fatty acids and Vitamin E contents with nutrition labeling

Encapsulated specialty oils commercialized in São Paulo state, Brazil, were evaluated for their identity (fatty acids profile) and compliance with nutrition labeling (fatty acids and Vitamin E (alpha tocopherol) contents). Twenty one samples [flaxseed oil (6), evening primrose (5), safflower (8), borage (1), and black currant (1)] purchased from local markets or collected by the health surveillance agency were analyzed. The fatty acids and vitamin E contents were analyzed by gas chromatography with flame ionization detector and liquid chromatography with UV detector, respectively. Nine samples were adulterated (5 samples of safflower oil, 3 of flaxseed oil, and one of evening primrose). Among them, 3 flaxseed and 2 safflower oil samples were probably adulterated by the addition of soybean oil. Conjugated linoleic acid (CLA) was found in two safflower oils samples although the sale of oils with conjugated linoleic acid (CLA) is not permitted by the National Health Surveillance Agency in Brazil (ANVISA). Only two samples presented all values in compliance with nutrition labeling (one safflower oil sample and one borage oil sample). The results show that a continuous monitoring of encapsulated specialty oils commercialized in Brazil is necessary including a greater number of samples and sanitary surveillance.

Identity of care in a Psychosocial Care Center for Children and Adolescents who uses drugs

Objective To associate the territory of identity with the production of care within a PCC focusing on children and adolescents with drug abuse and their institutional identity. Method We used the “ process tracing methodology” in four research categories: focus groups, characterization of professionals, observing the everyday and interviewing two members of emblematic cases of the service. Results territory of identity of the institution, which operates the production of care is crossed by the difficulty of dealing with the complexity brought by the users and the performance of the PCC network. This paper is also permeated by different conceptions of care and small problematization of these issues in collective spaces of service. Conclusion The discussion in focus groups and other devices can be powerful resources to reframe the meaning of care and identity of collective service.

Histopathological aspects of Bovine Enzootic Hematuria in Brazil

The bladder lesions of 59 cattle, from the States of Rio de Janeiro, São Paulo, Minas Gerais, Espírito Santo, Rio Grande do Sul, Santa Catarina, Paraná and Amazon, affected by Bovine Enzootic Haematuria (BEH), were studied histologically. The objective of this study was to describe and reclassify neoplastic and non-neoplastic alterations not yet reported, according to the more complete current nomenclature used in human medicine. There was an almost complete identity with alterations observed in the bladder of man. Due to the occurrence of two or more neoplasms in the same animal, differences in the methodology and in the concept of classification, a more precise comparison was not possible. Coexistence of different types of epithelial and/or mesenchymal tumour growth was frequently seen. Rare neoplasms or differentiations not previously described were found in the bladder of some animals affected by BEH. These were trabecular carcinoma with Paneth cells differentiation, mesonephroid adenoma, mesonephroid adenocarcinoma, "signet ring" cell carcinoma, plasmocytoid carcinoma, chromophobe cell carcinoma and nested type of transitional cell carcinoma. Haemangiosarcomas originating from haemangiomas were also observed. This study also revealed the occurrence of many tumors with anaplasia and pronounced infiltrative features, but which did not metastasize. The elucidation of the cause of this "barrier against metastases" and its relationship with chemical carcinogenesis induced by the ptaquiloside, the active principle of bracken fern (Pteridium aquilinum), could be of interest to future research on the control ofneoplasia in man and animals.

Lethality of triatomines (Hemiptera: Reduviiae), vectors of Chagas' disease, feeding on blood baits containing synthetic insecticides, under laboratory conditions

A laboratory study was conducted to test the toxicity of synthetic insecticides added to defibrinated sheep blood kept at room temperature and offered as food to the following triatomine species: Triatoma infestans, Panstrongylus megistus, Triatoma vitticeps, Triatoma pseudomaculata, Triatoma brasiliensis and Rhodnius prolixus. The insecticides used, at a concentration of 1g/l, were: HCH, DDT, Malathion and Trichlorfon, and the lethalithy observed at the end of a 7-day period varied according to the active principle of each. HCH was the most effective by the oral route, killing 100% of the insects, except P. megistus (95.7%) and T. pseudomaculata (94.1%). Trichlorfon killed the insects at rates ranging from 71.8% (T. vitticeps) to 98% (R. prolixus). Malathion was slightly less efficient, killing the insects at rates from 56.8% (T. vitticeps) to 97% (T.brasiliensis). DDT was the least effective, with a killing rate of 10% (T. vitticeps) to 75% (T.brasiliensis). Since the tests were performed at room temperature, we suggest that baits of this type should be tried for the control of triatomines in the field.

Lethal effect of a bait for Rhodnius prolixus (Hemiptera: Reduviidae), the vector of Chagas' disease, containing hexachlorocyclohexane (HCH), under laboratory conditions

The lethal effect of a bait containing an aqueous hexachlorocyclohexane (HCH) suspension at the concentration of 1g/l and maintained at room temperature was studied in the laboratory over a period of 12 weeks. The suspension was placed in a latex bag hanging inside a 1000-ml beaker tightly covered with nylon netting, and left there with no changes for 85 days. Sixteen groups of R. prolixas bugs, consisting on average of 30 specimens each, were successively exposed to the bait and observed at different intervals for one week each. The mortality rate was 100% for all groups, except for the 16th, whose mortality rate was 96.7%. As the groups succeeded one another, mortality started to occur more rapidly and was more marked at the 6- and 24-h intervals. Later tests respectively started at 6:00 a.m. and 6:00 p.m. showed that diurnal and nocturnal periodicity in the offer of food had no effect on mortality. First- and 2nd- instar nymphs and adults male were more sensitive and 5th- instar nymphs were more resistant to the active principle of the bait.

The use of biodiversity as source of new chemical entities against defined molecular targets for treatment of malaria, tuberculosis, and T-cell mediated diseases: a review

The modern approach to the development of new chemical entities against complex diseases, especially the neglected endemic diseases such as tuberculosis and malaria, is based on the use of defined molecular targets. Among the advantages, this approach allows (i) the search and identification of lead compounds with defined molecular mechanisms against a defined target (e.g. enzymes from defined pathways), (ii) the analysis of a great number of compounds with a favorable cost/benefit ratio, (iii) the development even in the initial stages of compounds with selective toxicity (the fundamental principle of chemotherapy), (iv) the evaluation of plant extracts as well as of pure substances. The current use of such technology, unfortunately, is concentrated in developed countries, especially in the big pharma. This fact contributes in a significant way to hamper the development of innovative new compounds to treat neglected diseases. The large biodiversity within the territory of Brazil puts the country in a strategic position to develop the rational and sustained exploration of new metabolites of therapeutic value. The extension of the country covers a wide range of climates, soil types, and altitudes, providing a unique set of selective pressures for the adaptation of plant life in these scenarios. Chemical diversity is also driven by these forces, in an attempt to best fit the plant communities to the particular abiotic stresses, fauna, and microbes that co-exist with them. Certain areas of vegetation (Amazonian Forest, Atlantic Forest, Araucaria Forest, Cerrado-Brazilian Savanna, and Caatinga) are rich in species and types of environments to be used to search for natural compounds active against tuberculosis, malaria, and chronic-degenerative diseases. The present review describes some strategies to search for natural compounds, whose choice can be based on ethnobotanical and chemotaxonomical studies, and screen for their ability to bind to immobilized drug targets and to inhibit their activities. Molecular cloning, gene knockout, protein expression and purification, N-terminal sequencing, and mass spectrometry are the methods of choice to provide homogeneous drug targets for immobilization by optimized chemical reactions. Plant extract preparations, fractionation of promising plant extracts, propagation protocols and definition of in planta studies to maximize product yield of plant species producing active compounds have to be performed to provide a continuing supply of bioactive materials. Chemical characterization of natural compounds, determination of mode of action by kinetics and other spectroscopic methods (MS, X-ray, NMR), as well as in vitro and in vivo biological assays, chemical derivatization, and structure-activity relationships have to be carried out to provide a thorough knowledge on which to base the search for natural compounds or their derivatives with biological activity.

Characterization of anti-silencing factor 1 in Leishmania major

Anti-silencing factor 1 (ASF1) is a histone chaperone that contributes to the histone deposition during nucleosome assembly in newly replicated DNA. It is involved in chromatin disassembly, transcription activation and in the cellular response to DNA damage. In Leishmania major the ASF1 gene (LmASF1) is located in chromosome 20 and codes for a protein showing 67% of identity with the Trypanosoma brucei TbASF1a. Compared to orthologous proteins, LmASF1 conserves the main residues relevant for its various biological functions. To study ASF1 in Leishmania we generated a mutant overexpressing LmASF1 in L. major. We observed that the excess of LmASF1 impaired promastigotes growth rates and had no impact on cell cycle progress. Differently from yeast, ASF1 overproduction in Leishmania did not affect expression levels of genes located on telomeres, but led to an upregulation of proteins involved in chromatin remodelling and physiological stress, such as heat shock proteins, oxidoreductase activity and proteolysis. In addition, we observed that LmASF1 mutant is more susceptible to the DNA damaging agent, methyl methane sulphonate, than the control line. Therefore, our study suggests that ASF1 from Leishmania pertains to the chromatin remodelling machinery of the parasite and acts on its response to DNA damage.

Comprehensiveness in child healthcare teaching in Undergraduate Nursing: perspective of teachers

This qualitative study analyzed, from the teacher’s perspective, if the principle of comprehensiveness is included in child healthcare teaching in nursing education. The participants were 16 teachers involved in teaching child healthcare in eight undergraduate nursing programs. Data collection was performed through interviews that were submitted to thematic content analysis. The theory in teaching incorporates comprehensive care, as it is based on children’s epidemiological profile, child healthcare policies and programs, and included interventions for the promotion/prevention/rehabilitation in primary health care, hospitals, daycare centers and preschools. The comprehensive conception of health-disease process allows for understanding the child within his/her family and community. However, a contradiction exists between what is proposed and what is practiced, because the teaching is fragmented, without any integration among disciplines, with theory dissociated from practice, and isolated practical teaching that compromises the incorporation of the principle of comprehensiveness in child healthcare teaching.

Antioxidant protection of statins in acute kidney injury induced by sepsis

Objective Evaluating the effect of preconditioning with simvastatin in acute kidney injury induced by sepsis. Method Male adult Wistar rats were divided into the following groups: SHAM (control); SHAM+Statin (0.5 mg/kg simvastatin, orally); Sepsis (cecal puncture ligation – CPL); Sepsis+Statin. Physiological parameters, peritoneal fluid culture, renal function, oxidative metabolites, severity of acute kidney injury and animal survival were evaluated. Results The treatment with simvastatin in induced sepsis showed elevation of creatinine clearance with attenuation of generation of oxidative metabolites, lower severity of acute kidney injury and reduced mortality. Conclusion This investigation confirmed the renoprotection with antioxidant principle of the simvastatin in acute kidney injury induced by sepsis in an experimental model.

The role of primary care in the prevention and control of healthcare associated infections

Little research has been conducted to date on the role of primary health care (PHC) in the prevention of healthcare associated infections (HCAIs). The present article is a theoretical study of the principle of primum non nocere and aims to promote reflection on the role of PHC in HCAI prevention with emphasis on practical recommendations. The indirect and direct roles of PHC in HCAI prevention are debated in light of this guiding principle. With respect to the indirect role of PHC, we discuss the issues of hospital-centrism and ambulatory care-sensitive conditions. The article outlines a number of challenges faced by health services related to PHC’s direct role in HCAI prevention, highlights seven key components of HCAI prevention programmes within the PHC sphere and provides practical recommendations for HCAI control and prevention.


Fuzzy logic applied to the modeling of water dynamics in an Oxisol in northeastern Brazil

Modeling of water movement in non-saturated soil usually requires a large number of parameters and variables, such as initial soil water content, saturated water content and saturated hydraulic conductivity, which can be assessed relatively easily. Dimensional flow of water in the soil is usually modeled by a nonlinear partial differential equation, known as the Richards equation. Since this equation cannot be solved analytically in certain cases, one way to approach its solution is by numerical algorithms. The success of numerical models in describing the dynamics of water in the soil is closely related to the accuracy with which the water-physical parameters are determined. That has been a big challenge in the use of numerical models because these parameters are generally difficult to determine since they present great spatial variability in the soil. Therefore, it is necessary to develop and use methods that properly incorporate the uncertainties inherent to water displacement in soils. In this paper, a model based on fuzzy logic is used as an alternative to describe water flow in the vadose zone. This fuzzy model was developed to simulate the displacement of water in a non-vegetated crop soil during the period called the emergency phase. The principle of this model consists of a Mamdani fuzzy rule-based system in which the rules are based on the moisture content of adjacent soil layers. The performances of the results modeled by the fuzzy system were evaluated by the evolution of moisture profiles over time as compared to those obtained in the field. The results obtained through use of the fuzzy model provided satisfactory reproduction of soil moisture profiles.

The history of the rectilinear diameter law

The formulation of the so-called law of rectilinear diameter for the determination of the critical volume of substances in the concluding decades of the nineteenth century became in a very useful and acceptably exact alternative tool for researchers in the field of critical phenomena. Its corresponding original expression, and even those of its early few modifications, were so mathematically simple that their use did not limit to exclusively contribute to remove the by then experimental obstacle for the estimating of this critical parameter, but also extended along several decades in the increasing applications of the principle of corresponding states.

True believers: the recption of Descartes's meditations by Malebranche and Huet

Both Nicholas Malebranche and Pierre-Daniel Huet were at first positively influenced by Descartes's Meditations, and both came to perceive shortcomings in that work. With respect to mind-body dualism, Malebranche attempted to strengthen Descartes's position by jettisoning clarity and distinctness basing it instead on a principle of intentionality. Huet jettisoned the whole position in favor of skepticism. The source of their different responses lay in their different estimations of Descartes's integrity.