47 resultados para Inter-relation of concepts
Resumo:
To estimate the populational fluctuation of Chrysomya Robineau-Desvoidy, 1830 species and the relation of populational abundance around, six wind oriented trap (WOT) were placed in three distinct ecological areas (urban, rural and wild) in Pelotas, Rio Grande do Sul, Brazil, from February/1993 to January/1995. The flies were weekly collected. Captured species were Chrysomya albiceps Wiedmann, 1819, C. megacephala Fabricius, 1794 and C. putoria Wiedmann, 1830 with respective abundance of 64.5%, 19.7% and 0.9%, representing a total of 85.0% of 409,920 specimens of Calliphoridae. The three species demonstrated similarity in the populational fluctuation, except in the abundance. The populational peak ocurred in autum when the temperature decreases. In the months of July to November no fly was collected, recomposing the population in December, when the temperature surpassed 20ºC.
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In Brazil simian malaria is widely spread, being frequent in the Amazon region (10% of primates infected) and even more in the forested coastal mountains of the Southeastern and Southern regions (35% and 18% infected, respectively), but absent in the semi-arid Northeast. Only two species of plasmoidia have been found: the quartan-like Plasmodium brasilianum and the tertian-like P. simium, but the possible presence of other species is not excluded. P. brasilianum is found in all enzootic foci, but P. simium was detected only on the coast of the Southeastern and Southern regions, between parallels 20-S and 30-S. Nearly all hosts are monkeys (family Cebidae, 28 species harbouring plasmodia out of 46 examined) and very rarely marmosets or tamarins (family Callitrichidae, I especies out of 16). P. brasilianum was present in all infected species, P. simium in only two. The natural vector in the Southeastern and Southern regions was found to be Anopheles cruzi, but has not been conclusively identified in the Amazon. One natural, accidental human infection due to P. simium was observed. There is no evidence of the relation of the simian to human malaria in the Southeastern and Southern regions, where human malaria was eradicated in spite of the high rates of monkeys infected, but in the Amazon recent serological studies by other workers, revealing high positivity for P. brasilianum/P. malariae antibodies in local indians, would suggest that among them malaria might be regarded as a zoonosis.
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The authors revalidate the genus Mepraia, described in 1940 by Mazza, Gajardo & Jörg. The genus is monotypic and represented by the species M. spinolai (Porter, 1934). Based on the characteres described below the authors considered the separation of the genus Triatoma Laporte, 1832 and the return of the genus Mepraia. Strongly alar polymorphism, the abdomen of female with connexivum like in genus Dipetalogaster Usinger 1939, seven testicular follicles, like in Triatoma, however with a different relation of lenghts; external male genitalia showing a big and foliar process of the conjunctiva, vesica with an arch-shape, struts and endosoma process absent.
Resumo:
Hermanlentia n. gen. of Tribe Triatomini, with a List of Species of Triatominae (Hemiptera, Reduviidae) - Hermanlentia n. gen. was established in the tribe Triatomini, based on differences of external morphology, phallic structures and chromatic characters of Triatoma matsunoi Fernandez-Loayza 1989, in relation to other species of Triatoma. The head is long with disproportionally small eyes 1:0,16; the relation of the head and the pronotum is 1: 0,4; and the coloration of the hemelytron is whitish. Characters of the male genitalia that distinguish the new genus are the articulatory apparatus with twice the size of the aedeagus, phallosoma with fingerlike apex, 1 + 1 dorsal conjuntive processes with the inner edge toothed, and absence of endosoma process and vesica
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Fractal mathematics has been used to characterize water and solute transport in porous media and also to characterize and simulate porous media properties. The objective of this study was to evaluate the correlation between the soil infiltration parameters sorptivity (S) and time exponent (n) and the parameters dimension (D) and the Hurst exponent (H). For this purpose, ten horizontal columns with pure (either clay or loam) and heterogeneous porous media (clay and loam distributed in layers in the column) were simulated following the distribution of a deterministic Cantor Bar with fractal dimension H" 0.63. Horizontal water infiltration experiments were then simulated using Hydrus 2D software. The sorptivity (S) and time exponent (n) parameters of the Philip equation were estimated for each simulation, using the nonlinear regression procedure of the statistical software package SAS®. Sorptivity increased in the columns with the loam content, which was attributed to the relation of S with the capillary radius. The time exponent estimated by nonlinear regression was found to be less than the traditional value of 0.5. The fractal dimension estimated from the Hurst exponent was 17.5 % lower than the fractal dimension of the Cantor Bar used to generate the columns.
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In soils under no-tillage (NT), the continuous crop residue input to the surface layer leads to carbon (C) accumulation. This study evaluated a soil under NT in Ponta Grossa (State of Paraná, Brazil) for: 1) the decomposition of black oat (Avena strigosa Schreb.) residues, 2) relation of the biomass decomposition effect with the soil organic carbon (SOC) content, the particulate organic carbon (POC) content, and the soil carbon stratification ratio (SR) of an Inceptisol. The assessments were based on seven samplings (t0 to t6) in a period of 160 days of three transects with six sampling points each. The oat dry biomass was 5.02 Mg ha-1 at t0, however, after 160 days, only 17.8 % of the initial dry biomass was left on the soil surface. The SOC in the 0-5 cm layer varied from 27.56 (t0) to 30.07 g dm-3 (t6). The SR increased from 1.33 to 1.43 in 160 days. There was also an increase in the POC pool in this period, from 8.1 to 10.7 Mg ha-1. The increase in SOC in the 0-5 cm layer in the 160 days was mainly due to the increase of POC derived from oat residue decomposition. The linear relationship between SOC and POC showed that 21 % of SOC was due to the more labile fraction. The results indicated that the continuous input of residues could be intensified to increase the C pool and sequestration in soils under NT.
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This article presents the basic ideas that oriented the elaboration of the new Chemistry Curriculum for the High Schools in the State of Minas Gerais, Brazil. The main features of traditional Brazilian Chemistry Curriculum are critically discussed, namely, the excessive number of concepts, the overemphasis in procedures and rituals instead of chemical principles and the lack of relationship between the concepts and the social, technological and environmental contexts. Trying to overcome these features, the proposed curriculum deals with a fewer number of concepts, clearly related in a conceptual structure, opening space to a balanced emphasis on phenomena, theory and representation, and on conceptual and contextual aspects of chemical knowledge.
Resumo:
The contextualized understanding of concepts in Chemistry by students from other areas is a challenging task. In this experiment, the synthesis of biodiesel is done by base catalyzed transesterification of refined soy oil with methanol at room temperature and common glassware found in any chemistry laboratory. The proposal permits introducing several concepts, such as that of emulsion, viscosity and catalysis to illustrate an activity based on an actual problem. In this didactic approach, some common problems of biodiesel production, such as soap formation and phase separation, are introduced into the procedure in order to raise questions and motivate the students to participate in the experimental work and stimulate reflections about critical aspects of biodiesel production. This experiment was carried out in the first semester of 2006, in experimental general chemistry taken by physics and agricultural, civil and chemical engineering students of UNICAMP.
Resumo:
Principal component analysis (PCA) is a chemometric method that allows for the extraction of chemical information that would otherwise be impossible to determine. Teaching chemometrics to undergraduates can contribute to the overall professional development and training of new teachers, whose profiles have been gaining attention due to the current demand for data interpretation. In this study, a didactic experiment involving PCA is proposed. Spectrophotometry was used in the ultraviolet-visible (UV-Vis) region to assess the behavior of anthocyanins extracted from red cabbage at different pH values. The results suggest the possible separation of anthocyanin structures into three distinct groups, according to their chemical characteristics displayed in acid, neutral, and basic media. The objective is to develop educational materials targeted to undergraduate courses, which encompass a larger number of concepts and introduce instrumental techniques currently being employed in both academic research and the industrial sector. Specifically, the proposed experiment introduces concepts related to spectrophotometry in the UV-Vis range and the PCA chemometric method. The materials used are easily accessible, and UV-Vis spectroscopy equipment is less expensive in comparison with other spectroscopy methods.
Resumo:
Infection by Sugarcane yellow leaf virus (ScYLV) causes severe leaf symptoms in sugarcane (Saccharum spp.) hybrids, which indicate alterations in its photosynthetic apparatus. To gain an overview of the physiological status of infected plants, we evaluated chlorophyll a fluorescence and gas exchange assays, correlating the results with leaf metabolic surveys, i.e., photosynthetic pigments and carbohydrate contents. When compared to healthy plants, infected plants showed a reduction in potential quantum efficiency for photochemistry of photosystem (PSII) and alterations in the filling up of the plastoquinone (PQ) pool. They also showed reduction in the CO2 net exchange rates, probably as a consequence of impaired quantum yield. In addition, reductions were found in the contents of photosynthetic leaf pigments and in the ratio chlorophyll a/chlorophyll b (chla/chlb). Carbohydrate content in the leaves was increased as a secondary effect of the ScYLV infection. This article discusses the relation of virus replication and host defense responses with general alterations in the photosynthetic apparatus and in the metabolism of infected plants.
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Russell's theory of memory as acquaintance with the past seems to square uneasily with his definition of acquaintance as the converse of the relation of presentation of an object to a subject. We show how the two views can be made to cohere under a suitable construal of 'presentation', which has the additional appeal of bringing Russell's theory of memory closer to contemporary views on direct reference and object-dependent thinking than is usually acknowledged. The drawback is that memory as acquaintance with the past falls short of fulfilling Russell's requirement that knowledge by acquaintance be discriminating knowledge - a shortcoming shared by contemporary externalist accounts of knowledge from memory.
Resumo:
OBJECTIVE: To evaluate the relation of medical research, with the participation of prominent plastic surgeon in Congress.METHODS: We reviewed the scientific programs of the last 3 Brazilian Congress of Surgery, were selected 21 Brazilian plástic surgeons invited to serve as panelists or speakers in roundtable sessions in the last 3 congresses (Group 1). We randomly selected and paired by other members (associates) of the Brazilian Society of Plastic Surgery, with no participation in congress as speaker (Group 2). We conducted a search for articles published in journals indexed in Medline, Lilacs and SciELO for all doctors selected during the entire academic career and the last 5 years from March 2007 until March 2012. We assessed the research activity through the simple counting of the number of publications in indexed journals for each professional. The number of publications groups was compared.RESULTS: articles produced throughout career: Group 1- 639 articles (average of 30.42 items each). Group 2- 79 articles (mean 3.95 articles each). Difference between medias: p <0.001.CONCLUSION: The results demonstrate that the Brazilian Society of Plastic Surgery seeking professionals with a greater number of publications and journals of higher impact. This approach encourages new members to pursue a higher qualification, and give security to congressmen, they can rely on the existence of a technical criterion in the choice of speakers.
Resumo:
PURPOSE: The objective of this study was to investigate the relationship between overactive bladder syndrome and anxiety in older women.METHODS: Of the 198 older women who were invited, 29 were excluded and 166 were then divided into two groups according to the Advanced Questionnaire of Overactive Bladder (OAB-V8): one group with overactive bladder symptoms (OAB-V8≥8) and the other without the symptoms of an overactive bladder (OAB-V8<8). The purpose was to conduct a frequency analysis and to investigate the relation of the social demographic data and anxiety in the two groups. The Beck Anxiety Inventory (BAI) was used to evaluate the level of anxiety. The Kolmogorov-Smirnov test was used to determine the distribution of the data. The differences between the two groups for the continuous variables were analyzed by the Mann-Whitney U test, the differences for the categorical variables were analyzed by the Chi-Square test and the association between the continuous variables was analyzed by the Spearman Correlation test. The tests were two-tailed with a confidence level of 5%.RESULTS: Overall, the frequency of an overactive bladder was present in 117 (70.5%) of the participants. The body mass index (BMI) of the group with overactive bladder symptoms was significantly higher than the BMI of those without these symptoms (p=0.001). A higher prevalence of mild, moderate and severe anxiety was observed among older women with overactive bladder symptoms. In addition, the overactive bladder symptoms group presented a positive low correlation with anxiety symptoms (r=0.345) and with BMI (r=0.281). There was a small correlation between BMI and anxiety symptoms (r=0.164).CONCLUSIONS: Overactive bladder syndrome was prevalent among older women and the existence of these symptoms was linked to the presence of mild, moderate and/or severe anxiety symptoms.
Resumo:
At the present time, protein folding is an extremely active field of research including aspects of biology, chemistry, biochemistry, computer science and physics. The fundamental principles have practical applications in the exploitation of the advances in genome research, in the understanding of different pathologies and in the design of novel proteins with special functions. Although the detailed mechanisms of folding are not completely known, significant advances have been made in the understanding of this complex process through both experimental and theoretical approaches. In this review, the evolution of concepts from Anfinsen's postulate to the "new view" emphasizing the concept of the energy landscape of folding is presented. The main rules of protein folding have been established from in vitro experiments. It has been long accepted that the in vitro refolding process is a good model for understanding the mechanisms by which a nascent polypeptide chain reaches its native conformation in the cellular environment. Indeed, many denatured proteins, even those whose disulfide bridges have been disrupted, are able to refold spontaneously. Although this assumption was challenged by the discovery of molecular chaperones, from the amount of both structural and functional information now available, it has been clearly established that the main rules of protein folding deduced from in vitro experiments are also valid in the cellular environment. This modern view of protein folding permits a better understanding of the aggregation processes that play a role in several pathologies, including those induced by prions and Alzheimer's disease. Drug design and de novo protein design with the aim of creating proteins with novel functions by application of protein folding rules are making significant progress and offer perspectives for practical applications in the development of pharmaceuticals and medical diagnostics.
Resumo:
Karl Popper versus Theodor Adorno: Lessons from a historical confrontation. In 1961, during the Congress of the German Society of Sociology, two great theoretical references of the XX century faced in a historical debate about the logic of the social sciences. In addition to methodological issues strict sense, the confrontation became known as a debate between positivism and dialectic. The article first deals with the theoretical trajectories of Popper and Adorno and the relation of their theories with their political and ideological certainties. On one hand, the trajectory of the Popperian epistemology is examined, its contributions and vigorous attacks on Marx in what he called 'poverty of historicism" and false predictive Marxist world, and, on the other hand, the role of Adorno in the Frankfurt School, his criticism of totalitarianism and the defense of a critical emancipatory reason. The article also deals with the confrontation itself, the exposure of Popper's twenty-seven theses that culminate with the situation logic and the method of the economy as exemplary for the social sciences and Adorno's critical perspective of sociology and society as non-separable objects. In conclusion we show how the articulation of theory with the weltanschauung of each author helps to clarify the terms of the debate and how the confrontation contributed unequivocally to the dynamics of scientific progress and for the critical history of the ideas.