Statistical Mechanics in the Extended Gaussian Ensemble

The extended gaussian ensemble (EGE) is introduced as a generalization of the canonical ensemble. The new ensemble is a further extension of the Gaussian ensemble introduced by J. H. Hetherington [J. Low Temp. Phys. {\bf 66}, 145 (1987)]. The statistical mechanical formalism is derived both from the analysis of the system attached to a finite reservoir and from the Maximum Statistical Entropy Principle. The probability of each microstate depends on two parameters $\beta$ and $\gamma$ which allow to fix, independently, the mean energy of the system and the energy fluctuations respectively. We establish the Legendre transform structure for the generalized thermodynamic potential and propose a stability criterion. We also compare the EGE probability distribution with the $q$-exponential distribution. As an example, an application to a system with few independent spins is presented.Comment: Revtex 4, 8 pages, 8 figure

Study Of Irradiated Bothropstoxin-1 With 60co Gamma Rays: Immune System Behavior

Ionizing radiation has been successfully employed to modify the immunological properties of biomolecules. Very promising results were obtained when crude animal venoms, as well as isolated toxins, were treated with 60Co gamma rays, yielding toxoids with good immunogenicity. The achievement of modified antigens with lower toxicity and preserved or improved immunogenicity can be very useful. Ionizing radiation has already been proven to be a powerful tool to attenuate snake venom toxicity without affecting, and even increasing, their immunogenic properties. However, little is known about the modifications that irradiated molecules undergo and even less about the immunological response that such antigens elicit. In the present work, we investigated the immunological behavior of bothropstoxin-1, a K49 phospholipase, before and after irradiation. Structural modifications of the toxin were analyzed by SDS-PAGE. Isogenic mice were immunized with either the native or the irradiated toxin. The circulating antibodies were isotyped and titrated by ELISA. According to our data, irradiation promoted structural modifications in the toxin characterized by higher molecular weight forms of proteins (aggregates and oligomers). The results also indicated that irradiated toxins were immunogenic and antibodies elicited by them were able to recognize the native toxin in ELISA. These findings suggest that irradiation of toxic proteins can promote significant modifications in their structures; however they still retain many of the original antigenic and immunological properties of native proteins. Also, our data indicate that irradiated proteins induce higher titers of IgG2a and IgG2b, suggesting that Th1 cells are predominantly involved in the immune response.152216225(1998) Secretaria Nacional de Ações Básicas de Saúde: Acidentes Ofídicos Contribuição Ao Estudo Da Morbidade, , Brasil. Ministério da Saúde. Brasília: Ministério da Saúde2 volsCupo, P., Azevedo-Marques, M.M., Menezes, J.B., Hering, S.E., Reações de hipersensibilidade imediata após uso intravenoso de soros antivenenos: Valor prognóstico dos testes de sensibilidade (1991) Rev Inst Med Trop São Paulo, 33 (2), pp. 115-122Abib, H., Laraba-Djebari, F., Effects of60Co gamma radiation on toxicity and hemorrhagic, myonecrotic, and edema-forming activities of Cerastes cerastes venom (2003) Can J Physiol Pharmacol, 81 (12), pp. 1125-1130Zamuner, S.R., Cruz-Höfling, M.A., Corrado, A.P., Hyslop, S., Rodrigues-Simioni, L., Comparison of the neurotoxic and myotoxic effects of Brazilian Bothrops venoms and their neutralization by commercial antivenom (2004) Toxicon, 44 (3), pp. 259-271Camey, K.U., Velarde, D.T., Sanchez, E.F., Pharmacological characterization and neutralization of the venoms used in the production of Bothropic antivenom in Brazil (2002) Toxicon, 40 (5), pp. 501-509. , DOI 10.1016/S0041-0101(01)00245-8, PII S0041010101002458Oshima-Franco, Y., Leite, G.B., Silva, G.H., Cardoso, D.F., Hyslop, S., Giglio, J.R., Cruz-Höfling, Ma., Rodrigues-Simioni, L., Neutralization of the pharmacological effects of bothropstoxin-1 from Bothrops jararacussu (jararacuçu) venom by crotoxin antiserum and heparin (2001) Toxicon, 39 (10), pp. 1477-1485Butler, J., Hoey, B.M., Swallow, A.J., Radiation chemistry (1987) Annu Rep Prog Chem, 83, pp. 129-175Garrison, W.M., Reaction mechanisms in the radiolysis of peptides, polypeptides, and proteins (1987) Chem Rev, 87 (2), pp. 381-398Grosh, D.S., Hoopywood, L.E., (1979) Biological Effects of Radiation. 2nd Ed., , New York: Academic PressNascimento, N.D., Seebart, C.S., Francis, B., Rogero, J.R., Kaiser, I.I., Influence of ionizing radiation on crotoxin: Biochemical and immunological aspects (1996) Toxicon, 34 (1), pp. 123-131. , DOI 10.1016/0041-0101(95)00111-5Delves, P.J., Roitt, I.M., The immune system. First of two parts (2000) New England Journal of Medicine, 343 (1), pp. 37-49. , DOI 10.1056/NEJM200007063430107Janeway, C.A., Travers, P., Walport, M., Shlomchik, M.J., (2002) Imunobiologia: O Sistema Imune Na Saúde e Na Doença, 767p. , Porto Alegre: Editora ArtMedSpencer, P.J., Aird, S.D., Boni-Mitake, M., Nascimento, N., Rogero, J.R., A single-step purification of bothropstoxin-1 (1998) Brazilian Journal of Medical and Biological Research, 31 (9), pp. 1125-1127Harlow, E., Lane, D., (1988) Antibodies. A Laboratory Manual, 726p. , New York: Cold Sprig Harbor LaboratoryVitaliano, S.N., Silva, D.A.O., Ferreira, R.A., Bevilacqua, E., Mineo, J.R., Avaliação dos níveis de anticorpos IgG anti-Toxoplasma gondii em lobos-guará (Chrysocyon brachyurus) por meio de ensaios imunoenzimáticos utilizando conjugados homólogos, heterólogos e de afinidade (2005) Horizonte Cient, 1, pp. 1-18Moon, S., Song, K.B., Effect of gamma-irradiation on the molecular properties of ovalbumin and ovomucoid and protection by ascorbic acid (2001) Food Chemistry, 74 (4), pp. 479-483. , DOI 10.1016/S0308-8146(01)00166-2, PII S0308814601001662Baptista, J.A., Spencer, P.J., Oliveira, J.E., Casare, M.S., Nascimento, N., Immune response against antigens irradiated with60Co gamma rays (2006) J Radioanal Nuclear Chem, 269 (3), pp. 565-569Brewer, J.M., Richmond, J., Alexander, J., The demonstration of an essential role for macrophages in the in vivo generation of IgG2a antibodies (1994) Clin Exp Immunol, 97 (1), pp. 164-171Sprent, J., Surh, C.D., T cell memory (2002) Annual Review of Immunology, 20, pp. 551-579. , DOI 10.1146/annurev.immunol.20.100101.15192

Economic models used in consequential life cycle assessment: a literature review

Réseau EcoSDThe construction sector is a key actor for achieving the sustainable development goals, particularly from an environmental point of view, due to the significant sector's contribution to energy consumption, greenhouse gas and pollutants emissions, waste generation, resources depletion etc. Life Cycle Assessment (LCA) is a multi-criteria tool to assess environmental impacts, preventing the impact transferring from one life cycle stage to another and thus is widely used to support decision-making. Consequential LCA (CLCA) can be particularly relevant for decisions involving non-marginal changes and may have an important role in supporting decision-makers of the construction sector by giving a wider comprehension of the environmental impacts associated with the changes caused by their decisions. Particularly when assessing large-scale consequences, it is recommended to couple an economic model to the CLCA methodology to assess the changes in the background system. Therefore, this research aims at reviewing the CLCA works applied to the construction sector and the use of economic models in CLCA for assessing non-marginal changes. For that, the review is divided in two parts: the first reviews the CLCA works and papers in the construction sector; and the second part reviews CLCA studies that assess non-marginal changes, regardless the activity or sector

Metal Surface Energy: Persistent Cancellation of Short-Range Correlation Effects beyond the Random-Phase Approximation

The role that non-local short-range correlation plays at metal surfaces is investigated by analyzing the correlation surface energy into contributions from dynamical density fluctuations of various two-dimensional wave vectors. Although short-range correlation is known to yield considerable correction to the ground-state energy of both uniform and non-uniform systems, short-range correlation effects on intermediate and short-wavelength contributions to the surface formation energy are found to compensate one another. As a result, our calculated surface energies, which are based on a non-local exchange-correlation kernel that provides accurate total energies of a uniform electron gas, are found to be very close to those obtained in the random-phase approximation and support the conclusion that the error introduced by the local-density approximation is small.Comment: 5 pages, 1 figure, to appear in Phys. Rev.

From Linear to Nonlinear Response in Spin Glasses: Importance of Mean-Field-Theory Predictions

Deviations from spin-glass linear response in a single crystal Cu:Mn 1.5 at % are studied for a wide range of changes in magnetic field, $\Delta H$. Three quantities, the difference $TRM-(MFC-ZFC)$, the effective waiting time, $t_{w}^{eff}$, and the difference $TRM(t_{w})-TRM(t_{w}=0)$ are examined in our analysis. Three regimes of spin-glass behavior are observed as $\Delta H$ increases. Lines in the $(T,\Delta H)$ plane, corresponding to ``weak'' and ``strong'' violations of linear response under a change in magnetic field, are shown to have the same functional form as the de Almeida-Thouless critical line. Our results demonstrate the existence of a fundamental link between static and dynamic properties of spin glasses, predicted by the mean-field theory of aging phenomena.Comment: 9 pages, 10 figure

A utilização da modelagem ambiental para sistematização do conhecimento tácito: identificação de corredores preferenciais para linhas de transmissão de energia elétrica

A necessidade de expansão do setor elétrico requer o aprimoramento constante das formas de projetar e executar empreendimentos como linhas de transmissão de energia elétrica. Embora, a disseminação de tecnologias de geoinformação estejam auxiliando a modernização desse processo, um dos grandes desafios é preservar o conhecimento acumulado ao longo dos anos de desenvolvimento de projetos. Os padrões de execução de projetos passados podem ser encontrados nas paisagens em que os mesmos foram executados. A hipótese avaliada neste trabalho é a possibilidade de empregar geotecnologia para extrair o conhecimento tácito através de padrões de execução de projetos lineares desenvolvidos no passado por meio da análise da paisagem, e utilizar tais informações em um processo de analise multicriterial para auxiliar a modelagem novos corredores de transmissão de energia. Este procedimento representa a oportunidade de estabelecer termos comparativos e parametrizados para interfacear às novas tecnologias e ganho de produtividade para modernizar o planejamento do setor de distribuição de energia. A investigação se apóia na análise multitemporal. Para tanto, a elaboração de um modelo espacialmente explícito e dinâmico faz-se necessária visando reconhecer não só o padrão espacial de ocorrência do fenômeno, mas também a sua variação na história. O presente trabalho emprega metodologias robustas, como Peso de Evidências e Least Costly Pathpara estudar o padrão espacial da localização de linhas de transmissão de energia na paisagem. Os resultados demonstram a viabilidade do uso de geoprocessamento e análise da paisagem, bem como a possibilidade de identificação de variáveis de caráter geográfico não consideradas nas tratativas normativas do setor, além de indicarem os locais de preferência para locação destes empreendimentos