17 resultados para international cooperation, partnership

em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP)


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Background: The cattle tick, Rhipicephalus (Boophilus) microplus, economically impact cattle industry in tropical and subtropical regions of the world. The morphological and genetic differences among R. microplus strains have been documented in the literature, suggesting that biogeographical and ecological separation may have resulted in boophilid ticks from America/Africa and those from Australia being different species. To test the hypothesis of the presence of different boophilid species, herein we performed a series of experiments to characterize the reproductive performance of crosses between R. microplus from Australia, Africa and America and the genetic diversity of strains from Australia, Asia, Africa and America. Results: The results showed that the crosses between Australian and Argentinean or Mozambican strains of boophilid ticks are infertile while crosses between Argentinean and Mozambican strains are fertile. These results showed that tick strains from Africa (Mozambique) and America (Argentina) are the same species, while ticks from Australia may actually represent a separate species. The genetic analysis of mitochondrial 12S and 16S rDNA and microsatellite loci were not conclusive when taken separately, but provided evidence that Australian tick strains were genetically different from Asian, African and American strains. Conclusion: The results reported herein support the hypothesis that at least two different species share the name R. microplus. These species could be redefined as R. microplus (Canestrini, 1887) (for American and African strains) and probably the old R. australis Fuller, 1899 (for Australian strains), which needs to be redescribed. However, experiments with a larger number of tick strains from different geographic locations are needed to corroborate these results.

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In geophysics and seismology, raw data need to be processed to generate useful information that can be turned into knowledge by researchers. The number of sensors that are acquiring raw data is increasing rapidly. Without good data management systems, more time can be spent in querying and preparing datasets for analyses than in acquiring raw data. Also, a lot of good quality data acquired at great effort can be lost forever if they are not correctly stored. Local and international cooperation will probably be reduced, and a lot of data will never become scientific knowledge. For this reason, the Seismological Laboratory of the Institute of Astronomy, Geophysics and Atmospheric Sciences at the University of Sao Paulo (IAG-USP) has concentrated fully on its data management system. This report describes the efforts of the IAG-USP to set up a seismology data management system to facilitate local and international cooperation.

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In this paper, we determine the lower central and derived series for the braid groups of the sphere. We are motivated in part by the study of Fadell-Neuwirth short exact sequences, but the problem is important in its own right. The braid groups of the 2-sphere S(2) were studied by Fadell, Van Buskirk and Gillette during the 1960s, and are of particular interest due to the fact that they have torsion elements (which were characterised by Murasugi). We first prove that for all n epsilon N, the lower central series of the n-string braid group B(n)(S(2)) is constant from the commutator subgroup onwards. We obtain a presentation of Gamma(2)(Bn(S(2))), from which we observe that Gamma(2)(B(4)(S(2))) is a semi-direct product of the quaternion group Q(8) of order 8 by a free group F(2) of rank 2. As for the derived series of Bn(S(2)), we show that for all n >= 5, it is constant from the derived subgroup onwards. The group Bn(S(2)) being finite and soluble for n <= 3, the critical case is n = 4 for which the derived subgroup is the above semi-direct product Q(8) (sic) F(2). By proving a general result concerning the structure of the derived subgroup of a semi-direct product, we are able to determine completely the derived series of B(4)(S(2)) which from (B(4)(S(2)))(4) onwards coincides with that of the free group of rank 2, as well as its successive derived series quotients.

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This work aimed to study the in vitro colonic fermentation profile of unavailable carbohydrates of two different kinds of unripe banana flour and to evaluate their postprandial glycemic responses. The unripe banana mass (UBM), obtained from the cooked pulp of unripe bananas (Musa acuminata, Nanico variety), and the unripe banana starch (UBS), obtained from isolated starch of unripe banana, plantain type (Musa paradisiaca) in natura, were studied. The fermentability of the flours was evaluated by different parameters, using rat inoculum, as well as the glycemic response produced after the ingestion by healthy volunteers. The flours presented high concentration of unavailable carbohydrates, which varied in the content of resistant starch, dietary fiber and indigestible fraction (IF). The in vitro colonic fermentation of the flours was high, 98% for the UBS and 75% for the UBM when expressed by the total amount of SCFA such as acetate, butyrate and propionate in relation to lactulose. The increase in the area under the glycemic curve after ingestion of the flours was 90% lower for the UBS and 40% lower for the UBM than the increase produced after bread intake. These characteristics highlight the potential of UBM and UBS as functional ingredients. However, in vivo studies are necessary in order to evaluate the possible benefic effects of the fermentation on intestinal health.

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Background: Addressing human rights issues brings forth ethical and political responsibilities for occupational therapists and requires new epistemological and educational approaches. The way occupational therapists have faced these challenges has depended upon historical, cultural and social contexts. Aim and method: By means of literature review and historical analysis, this paper reflects on how occupational therapists have dealt with human matters issues and on the contemporary changes within the profession. Results and discussion: The paper portrays how Latin American occupational therapists have engaged in social transformation by choosing not to transform ethical and political problems into technical matters. Taking into account experiences and views from South Africa, Brazil and Chile, the paper outlines the importance of developing political literacy and interdisciplinary professional/postprofessional education to prepare the new generation of occupational therapists to engage in social transformation. Addressing issues of invisibility and lack of access to human rights, the paper reflects on the need of developing conceptual tools and strategies for change, and discusses the transformations being produced in contemporary occupational therapy. Conclusion: Occupational therapists and scientists need to be attentive to human rights issues. They also need to answer the call for interconnectedness in the present-day complex societies, and engage in networking and a cross-bordering dialogue. Nevertheless, although necessary and welcome, international cooperation requires a permanent exercise of cultural sensitivity, political awareness and self-awareness.

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Cancers of the upper aerodigestive tract [(UADT): oral cavity, pharynx, larynx and oesophagus] have high incidence rates in some parts of South America. Alterations in the TP53 gene are common in these cancers. In our study, we have estimated the prevalence and patterns of TP53 mutations (exons 4-10) in 236 UADT tumours from South America in relation to lifestyle risk factors, such as tobacco smoking and alcohol drinking. Moreover, we have conducted a pilot study of EGFR mutations (exons 18-21) in 45 tumours from the same population. TP53 mutation prevalence was high: 59% of tumours were found to carry mutant TP53. We found an association between TP53 mutations and tobacco smoking and alcohol drinking. The mutation rate increased from 38% in never-smokers to 66% in current smokers (P-value for trend = 0.09). G:C > T:A transversions were found only in smokers (15%). Alcohol drinkers carried more G:C > A:T transitions (P = 0.08). Non-exposed individuals were more probable to carry G:C > A:T transitions at CpG sites (P = 0.01 for never-smokers and P < 0.001 for never-drinkers). EGFR mutations were found in 4% of cases. Inactivation of TP53 by mutations is a crucial molecular event in the UADT carcinogenesis and it is closely related to exposure to lifestyle risk factors. EGFR mutations do not appear to be a common event in UADT carcinogenesis in this population.

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In this study, we describe the first survey in Thailand of Trypanosoma theileri, a widespread and prevalent parasite of cattle that is transmitted by tabanid flies. Investigation of 210 bovine blood samples of Thai cattle from six farms by hematocrit centrifuge technique (HCT) revealed 14 samples with trypanosomes morphologically compatible to T. theileri. Additional animals were positive for T. theileri by PCR based on the Cathepsin L-like sequence (TthCATL-PCR) despite negative by HCT, indicating cryptic infections. Results revealed a prevalence of 26 +/- 15% (95% CI) of T. theileri infection. Additionally, 12 samples positive for T. theileri were detected in cattle from other 11 farms. From a total of 30 blood samples positive by HCT and/or PCR from 17 farms, seven were characterized to evaluate the genetic polymorphism of T. theileri through sequence analysis of PCR-amplified CATL DNA sequences. All CATL sequences of T. theileri from Thai cattle clustered with sequences of the previously described phylogenetic lineages TthI and TthII, supporting only two major lineages of T. theileri in cattle around the world. However, 11 of the 29 CATL sequences analyzed showed to be different, disclosing an unexpectedly large polymorphic genetic repertoire, with multiple genotypes of T. theileri not previously described in other countries circulating in Thai cattle. (C) 2011 Elsevier B.V. All rights reserved.

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This paper presents an overview of the results obtained during the Joint Experiments organized in the framework of the IAEA Coordinated Research Project on `Joint Research Using Small Tokamaks` that have been carried out on the tokamaks CASTOR at IPP Prague, Czech Republic (2005), T-10 at RRC `Kurchatov Institute`, Moscow, Russia (2006), and the most recent one at ISTTOK at IST, Lisbon, Portugal, in 2007. Experimental programmes were aimed at diagnosing and characterizing the core and the edge plasma turbulence in a tokamak in order to investigate correlations between the occurrence of transport barriers, improved confinement, electric fields and electrostatic turbulence using advanced diagnostics with high spatial and temporal resolution. On CASTOR and ISTTOK, electric fields were generated by biasing an electrode inserted into the edge plasma and an improvement of the global particle confinement induced by the electrode positive biasing has been observed. Geodesic acoustic modes were studied using heavy ion beam diagnostics on T-10 and ISTTOK and correlation reflectometry on T-10. ISTTOK is equipped with a gallium jet injector and the technical feasibility of gallium jets interacting with plasmas has been investigated in pulsed and ac operation. The first Joint Experiments have clearly demonstrated that small tokamaks are suitable for broad international cooperation to conduct dedicated joint research programmes. Other activities within the IAEA Coordinated Research Project on Joint Research Using Small Tokamaks are also overviewed.

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Motivated in part by the study of Fadell-Neuwirth short exact sequences, we determine the lower central and derived series for the braid groups of the finitely-punctured sphere. For n >= 1, the class of m-string braid groups B(m)(S(2)\{x(1), ... , x(n)}) of the n-punctured sphere includes the usual Artin braid groups B(m) (for n = 1), those of the annulus, which are Artin groups of type B (for n = 2), and affine Artin groups of type (C) over tilde (for n = 3). We first consider the case n = 1. Motivated by the study of almost periodic solutions of algebraic equations with almost periodic coefficients, Gorin and Lin calculated the commutator subgroup of the Artin braid groups. We extend their results, and show that the lower central series (respectively, derived series) of B(m) is completely determined for all m is an element of N (respectively, for all m not equal 4). In the exceptional case m = 4, we obtain some higher elements of the derived series and its quotients. When n >= 2, we prove that the lower central series (respectively, derived series) of B(m)(S(2)\{x(1), ... , x(n)}) is constant from the commutator subgroup onwards for all m >= 3 (respectively, m >= 5). The case m = 1 is that of the free group of rank n - 1. The case n = 2 is of particular interest notably when m = 2 also. In this case, the commutator subgroup is a free group of infinite rank. We then go on to show that B(2)(S(2)\{x(1), x(2)}) admits various interpretations, as the Baumslag-Solitar group BS(2, 2), or as a one-relator group with non-trivial centre for example. We conclude from this latter fact that B(2)(S(2)\{x(1), x(2)}) is residually nilpotent, and that from the commutator subgroup onwards, its lower central series coincides with that of the free product Z(2) * Z. Further, its lower central series quotients Gamma(i)/Gamma(i+1) are direct sums of copies of Z(2), the number of summands being determined explicitly. In the case m >= 3 and n = 2, we obtain a presentation of the derived subgroup, from which we deduce its Abelianization. Finally, in the case n = 3, we obtain partial results for the derived series, and we prove that the lower central series quotients Gamma(i)/Gamma(i+1) are 2-elementary finitely-generated groups.

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Let M -> B, N -> B be fibrations and f(1), f(2): M -> N be a pair of fibre-preserving maps. Using normal bordism techniques we define an invariant which is an obstruction to deforming the pair f(1), f(2) over B to a coincidence free pair of maps. In the special case where the two fibrations axe the same and one of the maps is the identity, a weak version of our omega-invariant turns out to equal Dold`s fixed point index of fibre-preserving maps. The concepts of Reidemeister classes and Nielsen coincidence classes over B are developed. As an illustration we compute e.g. the minimal number of coincidence components for all homotopy classes of maps between S(1)-bundles over S(1) as well as their Nielsen and Reidemeister numbers.

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In this paper, we determine the lower central and derived series for the braid groups of the projective plane. We are motivated in part by the study of Fadell-Neuwirth short exact sequences, but the problem is interesting in its own right. The n-string braid groups B(n)(RP(2)) of the projective plane RP(2) were originally studied by Van Buskirk during the 1960s. and are of particular interest due to the fact that they have torsion. The group B(1)(RP(2)) (resp. B(2)(RP(2))) is isomorphic to the cyclic group Z(2) of order 2 (resp. the generalised quaternion group of order 16) and hence their lower central and derived series are known. If n > 2, we first prove that the lower central series of B(n)(RP(2)) is constant from the commutator subgroup onwards. We observe that Gamma(2)(B(3)(RP(2))) is isomorphic to (F(3) X Q(8)) X Z(3), where F(k) denotes the free group of rank k, and Q(8) denotes the quaternion group of order 8, and that Gamma(2)(B(4)(RP(2))) is an extension of an index 2 subgroup K of P(4)(RP(2)) by Z(2) circle plus Z(2). As for the derived series of B(n)(RP(2)), we show that for all n >= 5, it is constant from the derived subgroup onwards. The group B(n)(RP(2)) being finite and soluble for n <= 2, the critical cases are n = 3, 4. We are able to determine completely the derived series of B(3)(RP(2)). The subgroups (B(3)(RP(2)))((1)), (B(3)(RP(2)))((2)) and (B(3)(RP(2)))((3)) are isomorphic respectively to (F(3) x Q(8)) x Z(3), F(3) X Q(8) and F(9) X Z(2), and we compute the derived series quotients of these groups. From (B(3)(RP(2)))((4)) onwards, the derived series of B(3)(RP(2)), as well as its successive derived series quotients, coincide with those of F(9). We analyse the derived series of B(4)(RP(2)) and its quotients up to (B(4)(RP(2)))((4)), and we show that (B(4)(RP(2)))((4)) is a semi-direct product of F(129) by F(17). Finally, we give a presentation of Gamma(2)(B(n)(RP(2))). (C) 2011 Elsevier Inc. All rights reserved.

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Let M be a compact, connected non-orientable surface without boundary and of genus g >= 3. We investigate the pure braid groups P,(M) of M, and in particular the possible splitting of the Fadell-Neuwirth short exact sequence 1 -> P(m)(M \ {x(1), ..., x(n)}) hooked right arrow P(n+m)(M) (P*) under right arrow P(n)(M) -> 1, where m, n >= 1, and p* is the homomorphism which corresponds geometrically to forgetting the last m strings. This problem is equivalent to that of the existence of a section for the associated fibration p: F(n+m)(M) -> F(n)(M) of configuration spaces, defined by p((x(1), ..., x(n), x(n+1), ..., x(n+m))) = (x(1), ..., x(n)). We show that p and p* admit a section if and only if n = 1. Together with previous results, this completes the resolution of the splitting problem for surface pure braid groups. (C) 2009 Elsevier B.V. All rights reserved.

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We classify the ( finite and infinite) virtually cyclic subgroups of the pure braid groups P(n)(RP(2)) of the projective plane. The maximal finite subgroups of P(n)(RP(2)) are isomorphic to the quaternion group of order 8 if n = 3, and to Z(4) if n >= 4. Further, for all n >= 3, the following groups are, up to isomorphism, the infinite virtually cyclic subgroups of P(n)(RP(2)): Z, Z(2) x Z and the amalgamated product Z(4)*(Z2)Z(4).

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The first one-pot synthesis of neutral and electron-rich [hydroxy(tosyloxy)iodo]arenes (HTIBs) from iodine and arenes is presented, thereby avoiding the need for expensive iodine(III) precursors. A large set of including a polyfluorinated analogue, can be obtained from the corresponding aryl iodide under the same conditions. The reaction proceeds under mild conditions, without excess reagents, and is fast and high-yielding. Together, the two presented routes give access to a wide range of HTIBs, which are useful reagents in a variety of synthetic transformations.

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Three water-insoluble, micelle-anchored flavylium salts, 7-hydroxy-3-octyl-flavylium chloride, 4`-hexyl-7-hydroxyflavylium chloride, and 6-hexyl-7-hydroxy-4-methyl-flavylium chloride, have been employed to probe excited-state prototropic reactions in micellar sodium dodecyl sulfate (SDS). In SDS micelles, the fluorescence decays of these three flavylium salts are tetraexponential functions in the pH range from 1.0 to 4.6 at temperatures from 293 to 318 K. The four components of the decays are assigned to Four kinetically coupled excited species in the micelle: specifically, promptly deprotonable (AH(+)*) and nonpromptly deprotonable (AH(h)(+)*) orientations of the acid in the micelle. the base-proton geminate pair (A*center dot center dot center dot H(+)), and the free conjugate base (A*). The initial prompt deprotonation to form the germinate pair occurs at essentially the same rate (k(d) similar to 6-7 x 10(10) s(-1)) for all three photoacids. Recombination of the germinate pair is similar to 3-fold faster than the rate of proton escape from the pair (k(rec) similar to 3 x 10(10) s(-1) and k(diss) similar to 1 x 10(10) s(-1)), corresponding to an intrinsic recombination efficiency of the pair of similar to 75%. Finally, the reprotonation of the short-lived free A* (200-350 ps, depending oil the photoacid) has two components, only one of which depends oil the proton concentration in the intermicellar aqueous phase. Ultrafast transfer of the proton to water and substantial compartmentalization of the photogenerated proton at the micelle surface Oil the picosecond time scale strongly suggest preferential transfer of the proton to preformed hydrogen-bonded water bridges between the photoacid and the anionic headgroups. This localizes the proton in the vicinity of the excited base much more efficiently than ill bulk water, resulting ill the predominance of geminate re reprotonation at the micelle surface.