958 research outputs found
Social and alternative banking: project selection and monitoring after the New Basel Capital Accord
Any economic activity calls for the exercise of moral judgement. There are some economic activities that actively promote collective benefit as a primary or secondary aim, and there are others that aim to increase the value of a firm. Investment decisions always have collective impact, but collective returns may be ignored or considered less important in company management if the objective is the maximisation of shareholder wealth. The allocative function exercised by banks in their credit activity may take this into account. Some banks nowadays focus on social profile, while others integrate the traditional approach with this new sensibility. But unfortunately banking regulations governing stability and soundness of the financial system make no mention of the social profile. The New Basel Capital Accord was an opportunity to recognise that bank's objectives may not consist only of the maximisation of shareholder wealth. But it was a missed opportunity, in that it gave advantages to traditional commercial banks and not to banks focussing on collective goals. This paper puts forward proposals for integrating the Basel II framework with profiles of collective bank credit policy. Social credit evaluation methods could help to identify those ethical banks which are more successful in meeting collective objectives. A sustainable credit appraisal methodology could have been examined by the Basel Committee and could have incentivated sustainable banking by giving it specific advantages.social banking, alternative banking, socially responsible investing, investments appraisal, Basel II, new capital accord
Soluble CD40 ligand can replace the normal T cell-derived CD40 ligand signal to B cells in T cell-dependent activation
We have constructed a soluble chimeric fusion protein between the mouse CD8 alpha chain and the mouse CD40 T cell ligand. This protein binds to both human and mouse B cells. By itself it induced a modest degree of B cell proliferation, but together with anti-immunoglobulin (anti-Ig) antibody it greatly stimulated B cell proliferation, as determined by both [3H]thymidine uptake and increase in cell numbers. These data are evidence that the CD40 ligand on T cells provides a signal that drives B cell proliferation. This signal is synergistic with that delivered by anti-Ig antibody
Thermally stimulated H emission and diffusion in hydrogenated amorphous silicon
We report first principles ab initio density functional calculations of
hydrogen dynam- ics in hydrogenated amorphous silicon. Thermal motion of the
host Si atoms drives H diffusion, as we demonstrate by direct simulation and
explain with simple models. Si-Si bond centers and Si ring centers are local
energy minima as expected. We also describe a new mechanism for break- ing Si-H
bonds to release free atomic H into the network: a fluctuation bond center
detachment (FBCD) assisted diffusion. H dynamics in a-Si:H is dominated by
structural fluctuations intrinsic to the amorphous phase not present in the
crystal.Comment: 4 pages, 5 figures, In press EPL (Jun. 2007
Factors Responsible for the Stability and the Existence of a Clean Energy Gap of a Silicon Nanocluster
We present a critical theoretical study of electronic properties of silicon
nanoclusters, in particular the roles played by symmetry, relaxation, and
hydrogen passivation on the the stability, the gap states and the energy gap of
the system using the order-N [O(N)] non-orthogonal tight-binding molecular
dynamics and the local analysis of electronic structure.Comment: 26 pages including figure
Variable domain N-linked glycosylation and negative surface charge are key features of monoclonal ACPA: implications for B-cell selection
Autoreactive B cells have a central role in the pathogenesis of rheumatoid
arthritis (RA), and recent findings have proposed that anti-citrullinated
protein autoantibodies (ACPA) may be directly pathogenic. Herein, we
demonstrate the frequency of variable-region glycosylation in single-cell
cloned mAbs. A total of 14 ACPA mAbs were evaluated for predicted N-linked
glycosylation motifs in silico and compared to 452 highly-mutated mAbs from RA
patients and controls. Variable region N-linked motifs (N-X-S/T) were
strikingly prevalent within ACPA (100%) compared to somatically hypermutated
(SHM) RA bone marrow plasma cells (21%), and synovial plasma cells from
seropositive (39%) and seronegative RA (7%). When normalized for SHM, ACPA
still had significantly higher frequency of N-linked motifs compared to all
studied mAbs including highly-mutated HIV broadly-neutralizing and
malaria-associated mAbs. The Fab glycans of ACPA-mAbs were highly sialylated,
contributed to altered charge, but did not influence antigen binding. The
analysis revealed evidence of unusual B-cell selection pressure and
SHM-mediated decreased in surface charge and isoelectric point in ACPA. It is
still unknown how these distinct features of anti-citrulline immunity may have
an impact on pathogenesis. However, it is evident that they offer selective
advantages for ACPA+ B cells, possibly also through non-antigen driven
mechanisms
Symbionts do not affect the mating incompatibility between the Brazilian-1 and Peruvian morphotypes of the Anastrepha fraterculus cryptic species complex
The South American fruit fly, Anastrepha fraterculus, is clearly undergoing a speciation process. Among others, two of their morphotypes, the Brazilian-1 and Peruvian, have accumulated differences in pre- and post-zygotic mechanisms resulting in a degree of reproductive isolation. Both harbor a different strain of Wolbachia, which is a widespread endosymbiotic bacterium among many invertebrates producing a range of reproductive effects. In this paper, we studied the role of this bacterium as one of the factors involved in such isolation process. Infected and cured laboratory colonies were used to test pre- and post-zygotic effects, with special emphasis in uni- and bi-directional cytoplasmic incompatibility (CI). We showed that Wolbachia is the only known reproductive symbiont present in these morphotypes. Wolbachia reduced the ability for embryonic development in crosses involving cured females and infected males within each morphotype (uni-directional CI). This inhibition showed to be more effective in the Peruvian morphotype. Bi-directional CI was not evidenced, suggesting the presence of compatible Wolbachia strains. We conclude that Wolbachia is not directly involved in the speciation process of these morphotypes. Other mechanisms rather than CI should be explored in order to explain the reduced mating compatibility between the Brazilian-1 and Peruvian morphotypes.Instituto de BiotecnologĂaFil: Devescovi, Francisco. Instituto Nacional de TecnologĂa Agropecuaria (INTA). Instituto de AgrobiotecnologĂa y BiologĂa Molecular; Argentina. Instituto Nacional de TecnologĂa Agropecuaria (INTA). Instituto de GenĂ©tica. Laboratorio de GenĂ©tica de Insectos de Importancia EconĂłmica; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Conte, Claudia Alejandra. Instituto Nacional de TecnologĂa Agropecuaria (INTA). Instituto de GenĂ©tica. Laboratorio de GenĂ©tica de Insectos de Importancia EconĂłmica; ArgentinaFil: Augustinos, Antonios A. Vienna International Centre. Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture. Insect Pest Control Laboratory; AustriaFil: Cancio Martinez, Elena I. Vienna International Centre. Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture. Insect Pest Control Laboratory; AustriaFil: Segura, Diego Fernando. Instituto Nacional de TecnologĂa Agropecuaria (INTA). Instituto de AgrobiotecnologĂa y BiologĂa Molecular; Argentina. Instituto Nacional de TecnologĂa Agropecuaria (INTA). Instituto de GenĂ©tica. Laboratorio de GenĂ©tica de Insectos de Importancia EconĂłmica; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Caceres, Carlos. Vienna International Centre. Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture. Insect Pest Control Laboratory; AustriaFil: Lanzavecchia, Silvia Beatriz. Instituto Nacional de TecnologĂa Agropecuaria (INTA). Instituto de GenĂ©tica "Ewald A. Favret"; ArgentinaFil: Bourtzis, Kostas. Vienna International Centre. Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture. Insect Pest Control Laboratory; Austri
Complete analysis of the B-cell response to a protein antigen, from in vivo germinal centre formation to 3-D modelling of affinity maturation
Somatic hypermutation of immunoglobulin variable region genes occurs within germinal centres (GCs) and is the process responsible for affinity maturation of antibodies during an immune response. Previous studies have focused almost exclusively on the immune response to haptens, which may be unrepresentative of epitopes on protein antigens. In this study, we have exploited a model system that uses transgenic B and CD4<sup>+</sup> T cells specific for hen egg lysozyme (HEL) and a chicken ovalbumin peptide, respectively, to investigate a tightly synchronized immune response to protein antigens of widely differing affinities, thus allowing us to track many facets of the development of an antibody response at the antigen-specific B cell level in an integrated system <i>in</i> <i>vivo</i>. Somatic hypermutation of immunoglobulin variable genes was analysed in clones of transgenic B cells proliferating in individual GCs in response to HEL or the cross-reactive low-affinity antigen, duck egg lysozyme (DEL). Molecular modelling of the antibody–antigen interface demonstrates that recurring mutations in the antigen-binding site, selected in GCs, enhance interactions of the antibody with DEL. The effects of these mutations on affinity maturation are demonstrated by a shift of transgenic serum antibodies towards higher affinity for DEL in DEL-cOVA immunized mice. The results show that B cells with high affinity antigen receptors can revise their specificity by somatic hypermutation and antigen selection in response to a low-affinity, cross-reactive antigen. These observations shed further light on the nature of the immune response to pathogens and autoimmunity and demonstrate the utility of this novel model for studies of the mechanisms of somatic hypermutation
Exceptionally potent human monoclonal antibodies are effective for prophylaxis and therapy of tetanus in mice
Human monoclonal antibodies were used here to study the mechanism of neuron intoxication by tetanus neurotoxin and to evaluate them as a safe preventive and therapeutic substitute of hyperimmune sera for tetanus in mice. By screening memory B cells of immune donors, we selected two monoclonal antibodies specific for tetanus neurotoxin with exceptionally high neutralizing activities, which were extensively characterized both structurally and functionally. We found that these antibodies interfere with the binding and translocation of the neurotoxin into neurons by interacting with two epitopes, whose definition pinpoints crucial events in the cellular pathogenesis of tetanus. This information explains the unprecedented neutralization ability of these antibodies, which were found to be exceptionally potent in preventing experimental tetanus when injected in mice long before the neurotoxin. Moreover, their Fab derivatives neutralized tetanus neurotoxin in post-exposure experiments, suggesting their potential therapeutic use via intrathecal injection. As such, these human monoclonal antibodies, as well as their Fab derivatives, meet all requirements for being considered for prophylaxis and therapy of human tetanus and are ready for clinical trials
Age-performance and intensity of grooming behavior toward Varroa destructor in resistant and susceptible Apis mellifera colonies
Grooming behavior confers resistance to honey bees against Varroa destructor, being of interest to social immunity studies and breeding programs. The objective of this study was to characterize at the individual level the grooming behavior of mite-resistant (R) and susceptible (S) A. mellifera stocks from Argentina. Assays were performed in experimental arenas by applying two treatments to nurse bees: (1) placing a V. destructor mite on the bee’s thorax and (2) touching the bee with a paintbrush. Grooming reactions were recorded on bees from both stocks at the ages of 6, 10, and 14 days after emergence. R bees exhibited lower time of first response against the mite, performed more cleaning attempts, and used all their legs with a higher probability compared to S bees. The same pattern was evident when younger and older bees from the R stock were compared. The results demonstrate that bee age and genetic origin are critical factors of grooming behavior in honey bees.Fil: Russo, Romina Maria. Instituto Nacional de TecnologĂa Agropecuaria. Centro de InvestigaciĂłn en Ciencias Veterinarias y AgronĂłmicas. Instituto de AgrobiotecnologĂa y BiologĂa Molecular. Grupo Vinculado Instituto de GenĂ©tica "Ewald A. Favret" al Iabimo | Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de AgrobiotecnologĂa y BiologĂa Molecular. Grupo Vinculado Instituto de GenĂ©tica "Ewald A. Favret" al Iabimo; ArgentinaFil: Landi, Lucas. Instituto Nacional de TecnologĂa Agropecuaria. Centro de InvestigaciĂłn de Recursos Naturales. Instituto de Recursos BiolĂłgicos; ArgentinaFil: Muntaabski, Irina. Instituto Nacional de TecnologĂa Agropecuaria. Centro de InvestigaciĂłn en Ciencias Veterinarias y AgronĂłmicas. Instituto de AgrobiotecnologĂa y BiologĂa Molecular. Grupo Vinculado Instituto de GenĂ©tica "Ewald A. Favret" al Iabimo | Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de AgrobiotecnologĂa y BiologĂa Molecular. Grupo Vinculado Instituto de GenĂ©tica "Ewald A. Favret" al Iabimo; ArgentinaFil: Liendo, MarĂa Clara. Instituto Nacional de TecnologĂa Agropecuaria. Centro de InvestigaciĂłn en Ciencias Veterinarias y AgronĂłmicas. Instituto de AgrobiotecnologĂa y BiologĂa Molecular. Grupo Vinculado Instituto de GenĂ©tica "Ewald A. Favret" al Iabimo | Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de AgrobiotecnologĂa y BiologĂa Molecular. Grupo Vinculado Instituto de GenĂ©tica "Ewald A. Favret" al Iabimo; ArgentinaFil: Pietronave, Hernán Pablo. Instituto Nacional de TecnologĂa Agropecuaria. Centro Regional Santa Fe. EstaciĂłn Experimental Agropecuaria Reconquista; ArgentinaFil: Merke, Julieta. Instituto Nacional de TecnologĂa Agropecuaria. Centro Regional Santa Fe. EstaciĂłn Experimental Agropecuaria Rafaela; ArgentinaFil: RodrĂguez, Graciela A.. Instituto Nacional de TecnologĂa Agropecuaria. Centro Regional Buenos Aires Sur. EstaciĂłn Experimental Agropecuaria Hilario Ascasubi; ArgentinaFil: Palacio, MarĂa A.. Universidad Nacional de Mar del Plata; Argentina. Instituto Nacional de TecnologĂa Agropecuaria; ArgentinaFil: Basilio, Alicia Mabel. Universidad de Buenos Aires. Facultad de Agronomia. Departamento de ProducciĂłn Animal. Cátedra de Avicultura, Cunicultura y Apicultura; ArgentinaFil: Lanzavecchia, Silvia Beatriz. Instituto Nacional de TecnologĂa Agropecuaria. Centro de InvestigaciĂłn en Ciencias Veterinarias y AgronĂłmicas. Instituto de AgrobiotecnologĂa y BiologĂa Molecular. Grupo Vinculado Instituto de GenĂ©tica "Ewald A. Favret" al Iabimo | Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de AgrobiotecnologĂa y BiologĂa Molecular. Grupo Vinculado Instituto de GenĂ©tica "Ewald A. Favret" al Iabimo; ArgentinaFil: Scannapieco, Alejandra Carla. Instituto Nacional de TecnologĂa Agropecuaria. Centro de InvestigaciĂłn en Ciencias Veterinarias y AgronĂłmicas. Instituto de AgrobiotecnologĂa y BiologĂa Molecular. Grupo Vinculado Instituto de GenĂ©tica "Ewald A. Favret" al Iabimo | Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de AgrobiotecnologĂa y BiologĂa Molecular. Grupo Vinculado Instituto de GenĂ©tica "Ewald A. Favret" al Iabimo; Argentin
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