1,379 research outputs found
Kinetics and Mechanism of Hydrolysis of Benzimidazolylcarbamates
Synthesis of new 2-aminobenzimidazole-1-carbamates was accomplished by carbamoylation of 2-aminobenzimidazole using different substituted phenyl chloroformates.
The aqueous hydrolysis of the new compounds was examined in the pH range 1-13 at 25 oC. The evaluated kinetic parameters led to the conclusion that up to pH 4 reaction proceeds by a bimolecular attack of water to the N-protonated substrate. This is the first time this behavior
is described for carbamates, and can be ascribed to the higher basicity of the benzimidazolyl moiety when compared with the carbonyl oxygen. For higher values of pH, the results are consistent with a BAc2 mechanism with nucleophilic catalysis, but while between pH 4 and pH 7 water acts as the nucleophile, for pH> 7 the hydroxide ion is the acting species
Governance: Concepts And Emergence In Brazilian Education
The text discusses the polysemy of the term governance in different fields of knowledge, with a particular emphasis on the field of Education. Then, it discusses the state-of-the-art of governance in the education area, from an analytical-descriptive literature review based on content analysis. This paper analyzes governance in specialized literature by conducting a survey of the papers found in the databases of the Scientific Electronic Library Online and the Brazilian Digital Library of Theses and Dissertations during the period 2004-2015. The results indicate that the term governance has been increasingly used in discussions about changes in the state's role and the phases of educational public policies, by force of the public-private partnerships. However, there is also a need to broaden the debate on educational governance in Brazilian academic circles, in view of the limited number of studies identified.249393996
Evidence Of Competition Between Two Canopy Ant Species: Is Aggressive Behavior Innate Or Shaped By A Competitive Environment?
Competition occurs in all ecological communities, although it has not always been experimentally tested as a structuring force in the distribution of species. We tested the hypothesis that the aggressiveness exhibited by Camponotus rufipes changes according to the pressures of a competitive environment. This is a dominant species in the montane forest of the Itacolomi State Park, Brazil, where Camponotus sericeiventris does not occur. Using bait traps in a field site where both species occur, (Juiz de Fora site) we showed that C. sericeiventris was able to remove C. rufipes workers at the same bait. In the laboratory, we used dyadic encounters to test workers from both species taken from colonies found in areas where both occur and where only C. rufipes was found. Camponotus rufipes from Itacolomi fought significantly less and was killed during the first few minutes in 60% of the events. On the other hand, the workers that co-existed with C. sericeiventris in the field were more aggressive, but less efficient fighters than the latter. This investigation demonstrated existence of competition between C. rufipes and C. sericeiventris, and also the lower aggressiveness of C. rufipes' individuals that did not co-exist in the field with C. sericeiventris. © 2012 Ndia Barbosa do Esprito Santo et al.Hlldobler, B., Wilson, E.O., (1990) The Ants, , Cambridge, Mass, USA The Belknap Press of Harvard University PressMacArthur, R.H., Levins, R., The limiting similarity, convergence, and divergence of coexisting species (1967) American Naturalist, 101, pp. 377-385Gotelli, N.J., Ellison, A.M., Assembly rules for New England ant assemblages (2002) Oikos, 99 (3), pp. 591-599. , DOI 10.1034/j.1600-0706.2002.11734.xWilson, E.O., (1971) The Insect Societies, , Cambridge, Mass, USA Harvard University PressDavidson, D.W., Resource discovery versus resource domination in ants: A functional mechanism for breaking the trade-off (1998) Ecological Entomology, 23 (4), pp. 484-490. , DOI 10.1046/j.1365-2311.1998.00145.xRoom, P.M., The relative distribution of ant species in Ghanas cocoa farms (1971) Journal of Animal Ecolog, 40, pp. 735-751Leston, D., The ant mosaic, tropical tree crops and the limiting of pests and diseases (1973) Pest Articles and News Summaries, 19, pp. 311-341Leston, D., A neotropical ant mosaic (1978) Annals of the Entomological Society of America, 71, pp. 649-653Majer, J.D., Delabie, J.H.C., Smith, M.R.B., Arboreal ant community patterns in Brazilian cocoa farms (1994) Biotropica, 26 (1), pp. 73-83Holldobler, B., Lumsden, C.J., Territorial strategies in ants (1980) Science, 210 (4471), pp. 732-739Savolainen, R., Vepsalainen, K., A competition hierarchy among boreal ants: Impact on resource partitioning and community structure (1988) Oikos, 51 (2), pp. 135-155Del-Claro, K., Oliveira, P.S., Ant-homoptera interactions in a neotropical savanna: The honeydew-producing treehopper, Guayaquila xiphias (Membracidae), and its associated ant fauna on Didymopanax vinosum (Araliaceae) (1999) Biotropica, 31 (1), pp. 135-144Orr, M.R., Dahlsten, D.L., Benson, W.W., Ecological interactions among ants in the genus Linepithema, their phorid parasitoids, and ant competitors (2003) Ecological Entomology, 28 (2), pp. 203-210. , DOI 10.1046/j.1365-2311.2003.00506.xFonseca, R.C., Diehl, E., Riqueza de formigas (Hymenoptera: Formicidae) epigéicas em povoamentos de Eucalyptus spp. (Myrtaceae) de diferentes idades no Rio Grande do Sul, Brasil (2004) Revista Brasileira de Entomologia, 48, pp. 95-100Peternelli, E.F.O., Della Lucia, T.M.C., Martins, S.V., Espécies de formigas que interagem com sementes de Mabea fistulifera Mart. (Euphorbiaceae) (2004) Revista Rvore, 28, pp. 733-738Lutinski, J.A., Garcia, F.R.M., Anlise faunstica de Formicidae (Hymenoptera: Apocrita) em ecossistema degradado no municpio de Chapec, Santa Catarina (2005) Biotemas, 18, pp. 73-86Santos, M.S., Louzada, J.N.C., Dias, N., Zanetti, R., Delabie, J.H.C., Nascimento, I.C., Litter ants richness (Hymenoptera, Formicidae) in remnants of a semi-deciduous forest in the Atlantic rain forest, Alto do Rio Grande region, Minas Gerais, Brazil (2006) Iheringia - Serie Zoologia, 96 (1), pp. 95-101. , http://www.scielo.br/pdf/isz/v96n1/a17v96n1.pdf, DOI 10.1590/S0073-47212006000100017Esprito Santo, N.B., (2008) Assembléia de Formigas Do Parque Estadual Do Itacolomi (MG) e Relaes Intra- E Interespecficas Entre Espécies Dominantes, M.S. Thesis, , Ps-Graduao em Comportamento e Biologia Animal/Departamento de Biologia Animal/Universidade Federal de Juiz de ForaYamamoto, M., Del-Claro, K., Natural history and foraging behavior of the carpenter ant Camponotus sericeiventris Guérin, 1838 (Formicinae, Campotonini) in the Brazilian tropical savanna (2008) Acta Ethologica, 11 (2), pp. 55-65Campos, R.I., Scares, J.P., Martins, R.P., Ribeiro, S.P., Effect of habitat structure on ant assemblages (Hymenoptera: Formicidae) associated to two pioneer tree species (2006) Sociobiology, 47 (3), pp. 721-738Fujaco, M.A.G., (2007) Influncia Dos Diferentes Tipos de Substrato e Geomorfologia Na Distribuio Espacial e Arquitetnica Do Gnero Eremanthus No Parque Estadual Do Itacolomi, Ouro Preto/MG, M.S. Thesis, , Ps-Graduao em Evoluo Crustal e Recursos Naturais/Departamento de Geologia/Universidade Federal de Ouro PretoBanco de Dados Climticos do BrasilEmbrapa Monitoramento por Satélite e EsalqUSP, , 2007, http://www.bdclima.cnpm.embrapa.br/resultados/balanco.php?UF=spCOD= 450Altmann, J., Observational study of behavior: Sampling methods (1974) Behaviour, 49 (34), pp. 227-267Ribeiro, S.P., Soares, J.P., Campos, R.I., Martins, R.P., Insect herbivores species associated to pioneer tree species: Contrasting within forest and ecotone canopy habitats (2008) Revista Brasileira de Zoocincias, 10, pp. 237-248Lopes, J.F.S., Hughes, W.O.H., Camargo, R.S., Forti, L.C., Larval isolation and brood care in Acromyrmex leaf-cutting ants (2005) Insectes Sociaux, 52 (4), pp. 333-338. , DOI 10.1007/s00040-005-0816-yErrard, C., Hefetz, A., Label familiarity and discriminatory ability of ants reared in mixed groups (1997) Insectes Sociaux, 44 (3), pp. 189-198. , DOI 10.1007/s000400050040Santos, J.C., Del-Claro, K., Ecology and behaviour of the weaver ant Camponotus (Myrmobrachys) senex (2009) Journal of Natural History, 43 (2324), pp. 1423-1435Ferreira Brando, C.R., Sequential ethograms along colony development of Odontomachus affinis Guérin (Hymenoptera, Formicidae, Ponerinae) (1983) Insectes Sociaux, 30 (2), pp. 193-203Santos, J.C., Yamamoto, M., Oliveira, F.R., Del-Claro, K., Behavioral repertory of the weaver ant Camponotus (Myrmobrachys) senex (Hymenoptera: Formicidae) (2005) Sociobiology, 46 (1), pp. 27-37Wilson, E.O., (1975) Sociobiology, , Cambridge, Mass, USA Belknap Press of Harvard University PressLangen, T.A., Tripet, F., Nonacs, P., The red and the black: Habituation and the dear-enemy phenomenon in two desert Pheidole ants (2000) Behavioral Ecology and Sociobiology, 48 (4), pp. 285-292Delsinne, T., Roisin, Y., Leponce, M., Spatial and temporal foraging overlaps in a Chacoan ground-foraging ant assemblage (2007) Journal of Arid Environments, 71 (1), pp. 29-44. , DOI 10.1016/j.jaridenv.2007.02.007, PII S0140196307000705Carroll, C.R., Janzen, D.H., Ecology of foraging by ants (1973) Annual Review of Ecology and Systematics, 4, pp. 231-257Byk, J., Del-Claro, K., Nectar- and pollen-gathering Cephalotes ants provide no protection against herbivory: A new manipulative experiment to test ant protective capabilities (2010) Acta Ethologica, 13 (1), pp. 33-38Jaffé, K., Snchez, C., On the nestmate-recognition system and territorial marking behaviour in the ant Camponotus rufipes (1984) Insectes Sociaux, 31 (3), pp. 302-315Lucas, C., (2002) Tude des Bases Chimiques et Comportamentales de la Formation du Visa Colonial Chez les Ponérines du Genre Pachycondyla, Thse Docteur, , Paris, France Biologie du Comportement, Universit Paris XIHlldobler, B., Wilson, E.O., The multiple recruitment systems of the african weaver ant Oecophylla longinoda (Latreille) (Hymenoptera: Formicidae) (1978) Behavioral Ecology and Sociobiology, 3 (1), pp. 19-60Hlldobler, B., Territoriality among Oecophylla (1979) National Geographic Society Research Reports, 1977, pp. 369-372Hlldobler, B., Territorial behavior in the green tree ant (Oecophylla smaragdina) (1983) Biotropica, 15, pp. 241-250De Vita, J., Mechanisms of interference and foraging among colonies of the harvester ant Pogonomyrmex californcus in the Mojave Desert (1979) Ecology, 60, pp. 729-73
Peripheral nerve injury and axonotmesis: State of the art and recent advances
Peripheral nerve lesions are frequent occurrences in both human and animal patients, leading to important physiological and labor complications that affect the quality of life of those who suffer the injury. More severe injuries are often associated with poor nerve regeneration and inadequate functional recovery, even with early medical and surgical interventions. Peripheral nerve crush lesions are frequent and, therefore, an experimental lesion paradigm widely used in researches involving nerve injury models and therapies for its resolution. In recent years, many studies have focused on innovative approaches to peripheral nerve treatment after crush injuries with more or less success. This review addresses the theme of peripheral nerve injury, with a special focus on the axonotmesis lesion, its etiology, pathophysiological mechanisms, methods of functional evaluation and regenerative processes, therapeutic options and corresponding recent advances
Cross-Correlation Studies with CMB Polarization Maps
The free-electron population during the reionized epoch rescatters CMB
temperature quadrupole and generates a now well-known polarization signal at
large angular scales. While this contribution has been detected in the
temperature-polarization cross power spectrum measured with WMAP data, due to
the large cosmic variance associated with anisotropy measurements at tens of
degree angular scales only limited information related to reionization, such as
the optical depth to electron scattering, can be extracted. The inhomogeneities
in the free-electron population lead to an additional secondary polarization
anisotropy contribution at arcminute scales. While the fluctuation amplitude,
relative to dominant primordial fluctuations, is small, we suggest that a
cross-correlation between arcminute scale CMB polarization data and a tracer
field of the high redshift universe, such as through fluctuations captured by
the 21 cm neutral Hydrogen background or those in the infrared background
related to first proto-galaxies, may allow one to study additional details
related to reionization. For this purpose, we discuss an optimized higher order
correlation measurement, in the form of a three-point function, including
information from large angular scale CMB temperature anisotropies in addition
to arcminute scale polarization signal related to inhomogeneous reionization.
We suggest that the proposed bispectrum can be measured with a substantial
signal-to-noise ratio and does not require all-sky maps of CMB polarization or
that of the tracer field. A measurement such as the one proposed may allow one
to establish the epoch when CMB polarization related to reionization is
generated and to address if the universe was reionized once or twice.Comment: 13 pages, 7 figures; Version in press with Phys. Rev.
Analysis of the influence of pharmacotherapy on the quality of life of seniors with osteoarthritis
AbstractAimsThis study aimed to assess the influence of pharmacotherapy on health-related quality of life of elderly with ostheoarthritis.MethodsLongitudinal study involving 91 older adults from both genders (Age: 70.36±5.57 years) from EELO project with self-reported knee or hip ostheoartritis, confirmed by radiographic analysis. Data regarding pharmacotherapy was assessed by a structured questionnaire and the quality of life was analyzed by SF-36 questionnaire at the initial moment and two years thereafter. All domains from quality of life were grouped in physical and mental components for further data analysis.ResultsA statistically significant decline in both physical and mental components of quality of life was observed (Wilcoxon test, p<0.05). However, it was observed a slighted decline in physical components in group treated with chondroitin/glucosamine when compared to other groups, according to Kruskal–Wallis test (p=0.007). On the other hand, it was not observed any influence of pharmacological treatment on mental components of health-related quality of life (p>0.05).ConclusionsTreatment with condroitin/glucosamin contributes to a lower decline in physical component while it had no influence on mental component of health-related quality of life in older adults with ostheoartritis
Reproducibility of peak power output during a 10-s cycling maximal effort using different sampling rates
Density and well width dependences of the effective mass of twodimensional holes in (100) GaAs quantum wells measured by cyclotron resonance at microwave frequencies
Cyclotron resonance at microwave frequencies is used to measure the band mass
(m_b) of the two-dimensional holes (2DH's) in carbon-doped (100)
GaAs/AlxGa1-xAs heterostructures. The measured m_b shows strong dependences on
both the 2DH density(p) and the GaAs quantum well width (W). For a fixed W, in
the density range (0.4x10^11 to 1.1x10^11 cm^-2) studied here, m_b increases
with p, consistent with previous studies of the 2DHs on the (311)A surface. For
a fixed p = 1.1x10^11 cm^-2, mb increases from 0.22 m_e at W = 10 nm to 0.50
m_e at W = 30 nm, and saturates around 0.51 m_e for W > 30 nm.Comment: to appear in Solid State Communication
Observing the First Stars and Black Holes
The high sensitivity of JWST will open a new window on the end of the
cosmological dark ages. Small stellar clusters, with a stellar mass of several
10^6 M_sun, and low-mass black holes (BHs), with a mass of several 10^5 M_sun
should be directly detectable out to redshift z=10, and individual supernovae
(SNe) and gamma ray burst (GRB) afterglows are bright enough to be visible
beyond this redshift. Dense primordial gas, in the process of collapsing from
large scales to form protogalaxies, may also be possible to image through
diffuse recombination line emission, possibly even before stars or BHs are
formed. In this article, I discuss the key physical processes that are expected
to have determined the sizes of the first star-clusters and black holes, and
the prospect of studying these objects by direct detections with JWST and with
other instruments. The direct light emitted by the very first stellar clusters
and intermediate-mass black holes at z>10 will likely fall below JWST's
detection threshold. However, JWST could reveal a decline at the faint-end of
the high-redshift luminosity function, and thereby shed light on radiative and
other feedback effects that operate at these early epochs. JWST will also have
the sensitivity to detect individual SNe from beyond z=10. In a dedicated
survey lasting for several weeks, thousands of SNe could be detected at z>6,
with a redshift distribution extending to the formation of the very first stars
at z>15. Using these SNe as tracers may be the only method to map out the
earliest stages of the cosmic star-formation history. Finally, we point out
that studying the earliest objects at high redshift will also offer a new
window on the primordial power spectrum, on 100 times smaller scales than
probed by current large-scale structure data.Comment: Invited contribution to "Astrophysics in the Next Decade: JWST and
Concurrent Facilities", Astrophysics & Space Science Library, Eds. H.
Thronson, A. Tielens, M. Stiavelli, Springer: Dordrecht (2008
Measurements of the SUSY Higgs self-couplings and the reconstruction of the Higgs potential
We address the issue of the reconstruction of the scalar potential of a
two-Higgs doublet model having in mind that of the MSSM.
We first consider the general CP conserving dim-4 effective potential. To
fully reconstruct this potential, we show that even if all the Higgs masses and
their couplings to the standard model particles are measured one needs not only
to measure certain trilinear Higgs self-couplings but some of the quartic
couplings as well. We also advocate expressing the Higgs self couplings in the
mass basis. We show explicitly, that in the so-called decoupling limit, the
most easily accessible Higgs self-couplings are given in terms of the Higgs
mass while all other dependencies on the parameters of the general effective
potential are screened. This helps also easily explain how, in the
MSSM, the largest radiative corrections which affect these self couplings are
reabsorbed by using the corrected Higgs mass. We also extend our analysis to
higher order operators in the effective Higgs potential. While the above
screening properties do not hold, we argue that these effects must be small and
may not be measured considering the foreseen poor experimental precision in the
extraction of the SUSY Higgs self-couplings.Comment: 25 pages, 3 figure
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