Fermion propagators in space-time

The one- and the two-particle propagators for an infinite non-interacting Fermi system are studied as functions of space-time coordinates. Their behaviour at the origin and in the asymptotic region is discussed, as is their scaling in the Fermi momentum. Both propagators are shown to have a divergence at equal times. The impact of the interaction among the fermions on their momentum distribution, on their pair correlation function and, hence, on the Coulomb sum rule is explored using a phenomenological model. Finally the problem of how the confinement is reflected in the momentum distribution of the system's constituents is briefly addressed.Comment: 26 pages, 9 figures, accepted for publication on Phys. Rev.

Connecting scaling with short-range correlations

We reexamine several issues related to the physics of scaling in electron scattering from nuclei. A basic model is presented in which an assumed form for the momentum distribution having both long- and short-range contributions is incorporated in the single-particle Green function. From this one can obtain saturation of nuclear matter for an NN interaction with medium-range attraction and short-range repulsion, and can obtain the density-density polarization propagator and hence the electromagnetic response and scaling function. For the latter, the shape of the scaling function and how it approaches scaling as a function of momentum transfer are both explored.Comment: 24 pages, 15 figures. A reference has been corrected and update

Pion photoproduction on the nucleon in the quark model

We present a detailed quark-model study of pion photoproduction within the effective Lagrangian approach. Cross sections and single-polarization observables are investigated for the four charge channels, $\gamma p\to \pi^+ n$, $\gamma n\to \pi^- p$, $\gamma p\to \pi^0 p$, and $\gamma n\to \pi^0 n$. Leaving the $\pi N\Delta$ coupling strength to be a free parameter, we obtain a reasonably consistent description of these four channels from threshold to the first resonance region. Within this effective Lagrangian approach, strongly constrainted by the quark model, we consider the issue of double-counting which may occur if additional {\it t}-channel contributions are included.Comment: Revtex, 35 pages, 16 eps figures; version to appear on PR

Structurally Diverse Covalent Triazine-based Framework Materials for Photocatalytic Hydrogen Evolution from Water

A structurally diverse family of 39 covalent triazine-based framework materials (CTFs) are synthesized by Suzuki–Miyaura polycondensation and tested as hydrogen evolution photocatalysts using a high-throughput workflow. The two best-performing CTFs are based on benzonitrile and dibenzo[b,d]thiophene sulfone linkers, respectively, with catalytic activities that are among the highest for this material class. The activities of the different CTFs are rationalized in terms of four variables: the predicted electron affinity, the predicted ionization potential, the optical gap, and the dispersibility of the CTFs particles in solution, as measured by optical transmittance. The electron affinity and dispersibility in solution are found to be the best predictors of photocatalytic hydrogen evolution activity

Vibrational mating disruption against insect pests: five years of experimentation in the vineyard

The use of vibrational signals in agriculture is becoming an important research topic as a new method of behavioural manipulation of insect pests. Semiophysicals include mechanical signals that have the potential to become environmentally friendly alternatives to pesticides. Like pheromones, vibrations endowed with specific spectral and temporal characteristics, can interfere with the mating behaviour of pests, thus preventing population outbreaks and crop damage. This approach is called "vibrational mating disruption" (VMD) and can be applied to control leafhoppers, insects that rely almost exclusively on vibrational signals for mating. Laboratory and semi-field tests have demonstrated that a species-specific mechanical stimulus transmitted to a plant (i.e., grapevine) by means of mini-shakers, can cause the total interruption of mating. In the present contribution, we report the results of a long-term research conducted on two target species, the leafhoppers Scaphoideus titanus and Hebata vitis. Since 2017 a field-scale experiment has been launched by setting up the first world 'vibrational vineyard' in the Trentino region (Italy) to evaluate the VMD efficacy. Every summer, the population density of the two insects has been measured by visual counting of the nymphs on leaves and yellow sticky traps for the adults. The efficiency of the actuator prototypes was monitored using highly sensitive equipment (laser Doppler vibrometer and accelerometers) and the transmission of vibrations in the trellis system was evaluated with a numerical model of the vineyard. Overall, the vibrational mating disruption technique proved to be effective in reducing the population density of both S. titanus and H. vitis as long as the disruptive signal was transmitted on the leaves above an active threshold of ca. 15 μm/s of amplitude. The use of vibrations to control pests in vineyards seems to be a promising innovation. Next step will be the application of the method on large vine surface

Blockade of Rho-associated kinase prevents inhibition of axon regeneration of peripheral nerves induced by anti-ganglioside antibodies

Neural Regeneration Research: Impact Factor 2022: 6.1Fil: Berardo, Andrés. Universidad Nacional de Córdoba, Córdoba, Argentina.Fil: Berardo, Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación Médica Mercedes y Martin Ferreyra. Laboratorio de Neurobiología, Argentina.Fil: Bacaglio, Cristian R. Universidad Nacional de Córdoba, Córdoba. Facultad de Ciencias Químicas. Departamento de Química Biológica, Argentina.Fil: Bacaglio, Cristian R. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones en Química Biológica de Córdoba, Argentina.Fil: Bacaglio, Cristian R. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación Médica Mercedes y Martin Ferreyra. Laboratorio de Neurobiología, Argentina.Fil: Báez, Bárbara B. Universidad Nacional de Córdoba, Córdoba. Facultad de Ciencias Químicas. Departamento de Química Biológica, Argentina.Fil: Báez, Bárbara B. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones en Química Biológica de Córdoba, Argentina.Fil: Báez, Bárbara B. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación Médica Mercedes y Martin Ferreyra. Laboratorio de Neurobiología, Argentina.Fil: Sambuelli, Rubén. Universidad Católica de Córdoba. Clínica Universitaria Reina Fabiola. Servicio de Anatomía Patológica, Argentina.Fil: Sheikh, Kazim A. University of Texas. Medical School at Houston. Department of Neurology, Texas, United States of America.Fil: Lopez, Pablo H. H. Universidad Nacional de Córdoba, Córdoba. Facultad de Ciencias Químicas. Departamento de Química Biológica, Argentina.Fil: Lopez, Pablo H. H. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones en Química Biológica de Córdoba, Argentina.Fil: Lopez, Pablo H. H. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación Médica Mercedes y Martin Ferreyra. Laboratorio de Neurobiología, Argentina.Anti-ganglioside antibodies are associated with delayed/poor clinical recovery in Guillain-Barrè syndrome, mostly related to halted axon regeneration. Crosslinking of cell surface gangliosides by anti-ganglioside antibodies triggers inhibition of nerve repair in in vitro and in vivo paradigms of axon regeneration. These effects involve the activation of the small GTPase RhoA/ROCK signaling pathways, which negatively modulate growth cone cytoskeleton, similarly to well stablished inhibitors of axon regeneration described so far. The aim of this work was to perform a proof of concept study to demonstrate the effectiveness of Y-27632, a selective pharmacological inhibitor of ROCK, in a mouse model of axon regeneration of peripheral nerves, where the passive immunization with a monoclonal antibody targeting gangliosides GD1a and GT1b was previously reported to exert a potent inhibitory effect on regeneration of both myelinated and unmyelinated fibers. Our results demonstrate a differential sensitivity of myelinated and unmyelinated axons to the pro-regenerative effect of Y-27632. Treatment with a total dosage of 9 mg/kg of Y-27632 resulted in a complete prevention of anti-GD1a/GT1b monoclonal antibody-mediated inhibition of axon regeneration of unmyelinated fibers to skin and the functional recovery of mechanical cutaneous sensitivity. In contrast, the same dose showed toxic effects on the regeneration of myelinated fibers. Interestingly, scale down of the dosage of Y-27632 to 5 mg/kg resulted in a significant although not complete recovery of regenerated myelinated axons exposed to anti-GD1a/GT1b monoclonal antibody in the absence of toxicity in animals exposed to only Y-27632. Overall, these findings confirm the in vivo participation of RhoA/ROCK signaling pathways in the molecular mechanisms associated with the inhibition of axon regeneration induced by anti-GD1a/GT1b monoclonal antibody. Our findings open the possibility of therapeutic pharmacological intervention targeting RhoA/Rock pathway in immune neuropathies associated with the presence of anti-ganglioside antibodies and delayed or incomplete clinical recovery after injury in the peripheral nervous system.info:eu-repo/semantics/publishedVersionFil: Berardo, Andrés. Universidad Nacional de Córdoba, Córdoba, Argentina.Fil: Berardo, Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación Médica Mercedes y Martin Ferreyra. Laboratorio de Neurobiología, Argentina.Fil: Bacaglio, Cristian R. Universidad Nacional de Córdoba, Córdoba. Facultad de Ciencias Químicas. Departamento de Química Biológica, Argentina.Fil: Bacaglio, Cristian R. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones en Química Biológica de Córdoba, Argentina.Fil: Bacaglio, Cristian R. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación Médica Mercedes y Martin Ferreyra. Laboratorio de Neurobiología, Argentina.Fil: Báez, Bárbara B. Universidad Nacional de Córdoba, Córdoba. Facultad de Ciencias Químicas. Departamento de Química Biológica, Argentina.Fil: Báez, Bárbara B. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones en Química Biológica de Córdoba, Argentina.Fil: Báez, Bárbara B. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación Médica Mercedes y Martin Ferreyra. Laboratorio de Neurobiología, Argentina.Fil: Sambuelli, Rubén. Universidad Católica de Córdoba. Clínica Universitaria Reina Fabiola. Servicio de Anatomía Patológica, Argentina.Fil: Sheikh, Kazim A. University of Texas. Medical School at Houston. Department of Neurology, Texas, United States of America.Fil: Lopez, Pablo H. H. Universidad Nacional de Córdoba, Córdoba. Facultad de Ciencias Químicas. Departamento de Química Biológica, Argentina.Fil: Lopez, Pablo H. H. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones en Química Biológica de Córdoba, Argentina.Fil: Lopez, Pablo H. H. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación Médica Mercedes y Martin Ferreyra. Laboratorio de Neurobiología, Argentina

Enteritis eosinofílica idiopática en una vaca lechera de Antioquia

RESUMEN La Enteritis Eosinofílica Idiopática (EEI) es una enfermedad de causa desconocida, reportada en los humanos y en varias especies animales. En el bovino se ha aceptado desde 1998 como una entidad poco común, con escasos reportes a nivel mundial. En este estudio se documenta una vaca que presentó inflamación intestinal de curso crónico, diagnosticada como EEI con base en el análisis de los hallazgos clínicos, histopatológicos y la exclusión de otras enfermedades intestinales. Esta comunicación constituye el primer reporte en Colombia de esta condición en el bovino y tiene como objetivo describir los hallazgos clínicos y anatomopatológicos encontrados y discutir sus posibles causas y mecanismos de enfermedad. Debido a que no se identificaron agentes infecciosos en el caso estudiado y a que la vaca presentó concomitantemente neoplasias, se postula como mecanismo de enfermedad más probable, el síndrome hipereosinofilia paraneoplásica

Determinants of intensive insulin therapeutic regimens in patients with type 1 diabetes: data from a nationwide multicenter survey in Brazil

Background: To evaluate the determinants of intensive insulin regimens (ITs) in patients with type 1 diabetes (T1D).Methods: This multicenter study was conducted between December 2008 and December 2010 in 28 public clinics in 20 Brazilian cities. Data were obtained from 3,591 patients (56.0% female, 57.1% Caucasian). Insulin regimens were classified as follows: group 1, conventional therapy (CT) (intermediate human insulin, one to two injections daily); group 2 (three or more insulin injections of intermediate plus regular human insulin); group 3 (three or more insulin injections of intermediate human insulin plus short-acting insulin analogues); group 4, basal-bolus (one or two insulin injections of long-acting plus short-acting insulin analogues or regular insulin); and group 5, basal-bolus with continuous subcutaneous insulin infusion (CSII). Groups 2 to 5 were considered IT groups.Results: We obtained complete data from 2,961 patients. Combined intermediate plus regular human insulin was the most used therapeutic regimen. CSII was used by 37 (1.2%) patients and IT by 2,669 (90.2%) patients. More patients on IT performed self-monitoring of blood glucose and were treated at the tertiary care level compared to CT patients (p < 0.001). the majority of patients from all groups had HbA1c levels above the target. Overweight or obesity was not associated with insulin regimen. Logistic regression analysis showed that economic status, age, ethnicity, and level of care were associated with IT (p < 0.001).Conclusions: Given the prevalence of intensive treatment for T1D in Brazil, more effective therapeutic strategies are needed for long term-health benefits.Farmanguinhos/Fundacao Oswaldo Cruz/National Health MinistryBrazilian Diabetes SocietyFundacao do Amparo a Pesquisa do Estado do Rio de JaneiroConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ Estado Rio de Janeiro, Unit Diabet, BR-20551030 Rio de Janeiro, BrazilBaurus Diabet Assoc, São Paulo, BrazilFed Univ São Paulo State, Diabet Unit, São Paulo, BrazilFed Univ Hosp Porto Alegre, Porto Alegre, BrazilUniv Hosp São Paulo, Diabet Unit, São Paulo, BrazilUniv Fed Rio de Janeiro, Rio de Janeiro, BrazilUniv Fed Ceara, Fortaleza, Ceara, BrazilSanta Casa Misericordia, Belo Horizonte, MG, BrazilSanta Casa Misericordia São Paulo, São Paulo, BrazilUniv Fed Amazonas, Manaus, Amazonas, BrazilHosp Geral de Bonsucesso, Rio de Janeiro, BrazilHosp Univ Clementino Fraga Filho IPPMG, Rio de Janeiro, BrazilUniv Hosp São Paulo, São Paulo, BrazilFac Ciencias Med Santa Casa São Paulo, São Paulo, BrazilUniv São Paulo, Inst Crianca, Hosp Clin, São Paulo, BrazilUniv São Paulo, Fac Med Ribeirao Preto, Hosp Clin, Ribeirao Preto, BrazilAmbulatorio Fac Estadual Med Sao Jose Rio Preto, Ribeirao Preto, BrazilEscola Paulista Med, Ctr Diabet, Ribeirao Preto, BrazilClin Endocrinol Santa Casa Belo Horizonte, Belo Horizonte, MG, BrazilUniv Estadual Londrina, Londrina, BrazilUniv Fed Parana, Hosp Clin, Porto Alegre, RS, BrazilInst Crianca Com Diabet Rio Grande Sul, Rio Grande Do Sul, RS, BrazilGrp Hosp Conceicao, Inst Crianca Com Diabet, Porto Alegre, RS, BrazilHosp Univ Santa Catarina, Florianopolis, SC, BrazilInst Diabet Endocrinol Joinville, Joinville, BrazilHosp Reg Taguatinga, Brasilia, DF, BrazilHosp Geral Goiania, Goiania, Go, BrazilCtr Diabet & Endocrinol Estado Bahia, Goiania, Go, BrazilUniv Fed Maranhao, Sao Luis, BrazilCtr Integrado Diabet & Hipertensao Ceara, Fortaleza, Ceara, BrazilUniv Fed Sergipe, Aracaju, BrazilHosp Univ Alcides Carneiro, Campina Grande, BrazilHosp Univ Joao de Barros Barreto, Belem, Para, BrazilFed Univ São Paulo State, Diabet Unit, São Paulo, BrazilUniv Hosp São Paulo, Diabet Unit, São Paulo, BrazilUniv Hosp São Paulo, São Paulo, BrazilEscola Paulista Med, Ctr Diabet, Ribeirao Preto, BrazilWeb of Scienc