Torsion-induced spin precession

We investigate the motion of a spinning test particle in a spatially-flat FRW-type space-time in the framework of the Einstein-Cartan theory. The space-time has a torsion arising from a spinning fluid filling the space-time. We show that for spinning particles with nonzero transverse spin components, the torsion induces a precession of particle spin around the direction of the fluid spin. We also show that a charged spinning particle moving in a torsion-less spatially-flat FRW space-time in the presence of a uniform magnetic field undergoes a precession of a different character.Comment: latex, 4 eps figure

Molecular and cytogenetic characterization of expanded B-cell clones from multiclonal versus monoclonal B-cell chronic lymphoproliferative disorders

Chronic antigen-stimulation has been recurrently involved in the earlier stages of monoclonal B-cell lymphocytosis, chronic lymphocytic leukemia and other B-cell chronic lymphoproliferative disorders. The expansion of two or more B-cell clones has frequently been reported in individuals with these conditions; potentially, such coexisting clones have a greater probability of interaction with common immunological determinants. Here, we analyzed the B-cell receptor repertoire and molecular profile, as well as the phenotypic, cytogenetic and hematologic features, of 228 chronic lymphocytic leukemia-like and non-chronic lymphocytic leukemia-like clones comparing multiclonal (n=85 clones from 41 cases) versus monoclonal (n=143 clones) monoclonal B-cell lymphocytosis, chronic lymphocytic leukemia and other B-cell chronic lymphoproliferative disorders. The B-cell receptor of B-cell clones from multiclonal cases showed a slightly higher degree of HCDR3 homology than B-cell clones from mono clonal cases, in association with unique hematologic (e.g. lower B-lymphocyte counts) and cytogenetic (e.g. lower frequency of cytogenetically altered clones) features usually related to earlier stages of the disease. Moreover, a subgroup of coexisting B-cell clones from individual multiclonal cases which were found to be phylogenetically related showed unique molecular and cytogenetic features: they more frequently shared IGHV3 gene usage, shorter HCDR3 sequences with a greater proportion of IGHV mutations and del(13q14.3), than other unrelated B-cell clones. These results would support the antigen-driven nature of such multiclonal B-cell expansions, with potential involvement of multiple antigens/epitopes

Stability of circular orbits of spinning particles in Schwarzschild-like space-times

Circular orbits of spinning test particles and their stability in Schwarzschild-like backgrounds are investigated. For these space-times the equations of motion admit solutions representing circular orbits with particles spins being constant and normal to the plane of orbits. For the de Sitter background the orbits are always stable with particle velocity and momentum being co-linear along them. The world-line deviation equations for particles of the same spin-to-mass ratios are solved and the resulting deviation vectors are used to study the stability of orbits. It is shown that the orbits are stable against radial perturbations. The general criterion for stability against normal perturbations is obtained. Explicit calculations are performed in the case of the Schwarzschild space-time leading to the conclusion that the orbits are stable.Comment: eps figures, submitted to General Relativity and Gravitatio

CLL-like B-lymphocytes are systematically present at very low numbers in peripheral blood of healthy adults

[EN] Chronic lymphocytic leukemia (CLL) is the most common type of leukemia in the Western world. The disease is typically diagnosed in adults >40 years old, who show an expansion (>5 × 109 cells per l) of clonal B-cells with a unique CD5+, CD23+, B-cell receptor (BCR)low immunophenotype in peripheral blood (PB) and bone marrow, frequently in association with involvement of other lymphoid tissues, disease symptoms and a heterogeneous clinical outcome. In parallel, monoclonal B-cell lymphocytosis (MBL), typically characterized by an expansion of clonal CLL-like B-cells (<5 × 109 cells per l), has been also frequently reported in otherwise asymptomatic subjects.1, 2 Increasing evidence suggests that this could represent a pre-leukemic condition, as CLL frequently develops in individuals with previous history of MBL, and MBL cases progress to CLL at a rate of 1% per year

Cognitive Learning Styles and Digital Equity: Searching for the Middle Way

This research is driven by a desire to understand the lifelong learner in the context of styles of learning and the emerging implications of technology enhanced learning for digital equity. Recognizing cognitive learning styles is the first step educators need to take in order to be most effective in working with students of diversity and bridging across formal and informal settings. Learning environments as a characterising feature of learning styles have undergone unprecedented change over the past decade with learning environments now blending physical and virtual space. To support the increasing diversity of learners pedagogy has to be fair, culturally responsive, equitable and relevant to the ‘virtual generation’. This in turn will inform our understanding of the ‘middle way’ in recognising cognitive learning styles , associated cultural context, and the implications to digital pedagogy equity

Partial oxidation of methane and methanol on FeOx-, MoOx- and FeMoOx -SiO2 catalysts prepared by sol-gel method: A comparative study

FeOx-, MoOx and FeMoOx-SiO materials prepared by a sol-gel procedure have been evaluated as catalysts for the partial oxidation of methane and methanol. The effect of decreasing the pH of the synthesis gel on the chemical nature of FeOx and MoOx species has been investigated. Characterization results show that low pH improves the dispersion of metal oxide species present in SiO matrix. For FeOx/SiO materials, the presence of dispersed FeOx species (rather than bulk FeO) improves the selectivity to formaldehyde in the partial oxidation of methane and methanol. For FeMoOx/SiOx catalysts, dispersed species favor the selectivity to formaldehyde only for methane oxidation. In contrast, for bimetallic FeMoOx/SiOx system, a better dispersion does not improve the selectivity to the aldehyde in methanol oxidation. In spite of the fact that the activation temperature for methane oxidation is remarkably higher than that for methanol oxidation, catalytic results show that the most active and selective catalysts for the partial oxidation of methane are also the most effective materials for the partial oxidation of methanol.The authors would like to acknowledge the MINECO in Spain (CRTl2018-099668-B-C21 and MAT2017-84118-C2-1-R projects) and Universidad Nacional de Colombia and Colciencias in Colombia for funding projects. Authors are grateful to the SCSIE, University of Valencia, for providing HR-TEM facility

Human peripheral blood B-Cell compartments: A crossroad in B-cell traffic

A relatively high number of different subsets of B-cells are generated through the differentiation of early B-cell precursors into mature B-lymphocytes in the bone marrow (BM) and antigen-triggered maturation of germinal center B-cells into memory B-lymphocytes and plasmablasts in lymphoid tissues. These B-cell subpopulations, which are produced in the BM and lymphoid tissues, recirculate through peripheral blood (PB), into different tissues including mucosa and the BM, where long-livi

The diagnostic importance of species specific and cross-reactive components of Taenia solium, Echinococcus granulosus, and Hymenolepis nana Importância diagnóstica da reação cruzada espécie-específica de componentes da Taenia solium, Echinococcus granulosus e Hymenolepis nana

Sera from patients infected with Taenia solium, Hymenolepis nana and Echinococcus granulosus were tested against homologous and heterologous parasite antigens using an ELISA assay, and a high degree of cross-reactivity was verified. To identify polypeptides responsible for this cross reactivity, the Enzyme Linked Immunoelectro Transfer Blot (EITB) was used. Sera from infected patients with T.solium, H.nana, and E.granulosus were assessed against crude, ammonium sulphate precipitated (TSASP), and lentil-lectin purified antigens of T.solium and crude antigens of.H.nana and E.granulosus. Several bands, recognized by sera from patients with T.solium, H.nana, and E.granulosus infections, were common to either two or all three cestodes. Unique reactive bands in H.nana were noted at 49 and 66 K-Da and in E.granulosus at 17-21 K-Da and at 27-32 K-Da. In the crude cysticercosis extract, a specific non glycoprotein band was present at 61-67 K-Da in addiction to specific glycoprotein bands of 50, 42, 24, 21, 18, 14, and 13 K-Da. None of the sera from patients with H.nana or E.granulosus infection cross reacted with these seven glycoprotein bands considered specific for T.solium infection.<br>Soros de pacientes infectados com Taenia solium, Hymenolepis nana e Echinococcus granulosus foram testados contra antígenos parasitários homólogos e heterólogos usando o teste de ELISA e foi verificado alto grau de reatividade cruzada. Para identificar os polipetídeos responsáveis por esta reatividade cruzada foi utilizado o teste "Enzyme Linked Immunoelectro Transfer Blot (EITB)". Soros de pacientes infectados por T.solium, H.nana, e E.granulosus foram colocados em contato com precipitado de sulfato de amônia e antígenos não purificados de T.solium e os de H.nana e E.granulosus. Várias bandas reconhecidas pelos soros de pacientes com infecção por T.solium, H.nana e E.granulosus foram comuns a dois ou três destes cestódeos. Uma única banda foi notada em H.nana a 49 e 66K-Da e no E.granulosus a 17-21 K-Da e 27-32 K-Da. No extrato não purificado de cisticercose uma banda específica não glicoproteica estava presente a 61-67 K-Da além das bandas de glicoproteínas específicas de 50, 42, 24, 21, 18, 14 e 13 K-Da. Nenhum destes soros de pacientes com infecção por H.nana ou E.granulosus reagiu de forma cruzada com estas sete bandas de glicoproteína consideradas específicas à infecção por T.soliu