Galectin-3-mediated glial crosstalk drives oligodendrocyte differentiation and (Re)myelination

Galectin-3 (Gal-3) is the only chimeric protein in the galectin family. Gal-3 structure comprises unusual tandem repeats of proline and glycine-rich short stretches bound to a carbohydrate-recognition domain (CRD). The present review summarizes Gal-3 functions in the extracellular and intracellular space, its regulation and its internalization and secretion, with a focus on the current knowledge of Gal-3 role in central nervous system (CNS) health and disease, particularly oligodendrocyte (OLG) differentiation, myelination and remyelination in experimental models of multiple sclerosis (MS). During myelination, microglia-expressed Gal-3 promotes OLG differentiation by binding glycoconjugates present only on the cell surface of OLG precursor cells (OPC). During remyelination, microglia-expressed Gal-3 favors an M2 microglial phenotype, hence fostering myelin debris phagocytosis through TREM-2b phagocytic receptor and OLG differentiation. Gal-3 is necessary for myelin integrity and function, as evidenced by myelin ultrastructural and behavioral studies from LGALS3-/- mice. Mechanistically, Gal-3 enhances actin assembly and reduces Erk 1/2 activation, leading to early OLG branching. Gal-3 later induces Akt activation and increases MBP expression, promoting gelsolin release and actin disassembly and thus regulating OLG final differentiation. Altogether, findings indicate that Gal-3 mediates the glial crosstalk driving OLG differentiation and (re)myelination and may be regarded as a target in the design of future therapies for a variety of demyelinating diseases.Fil: Thomas, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Biológica; ArgentinaFil: Pasquini, Laura Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Biológica; Argentin

The calculation of optical absorption spectra using linear-scaling density-functional theory

The goal of the work presented in this thesis was to develop and implement a method for calculating optical absorption spectra for large electronic systems within a linear-scaling density-functional theory (LS-DFT) formalism. The key feature of this method was the development of a scheme for optimizing a set of localized orbitals to accurately represent unoccupied Kohn-Sham states, which are not well represented by the localized orbital basis sets used for ground state LS-DFT calculations. Three different schemes were compared for the calculation of unoccupied states using a one-dimensional “toy model” and the most promising of these, based on the use of a projection operator, was implemented in a fully-functional LS-DFT code. Using the toy model, two methods for the calculation of band structures within a localized basis set were investigated and some of the features required by localized basis sets in order to produce accurate band structures were identified. The method was tested by the application to both molecular and extended systems, with calculations of densities of states, band structures and optical absorption spectra. The results for the smaller systems were validated by comparison with a cubic-scaling plane-wave density-functional theory code, with which excellent agreement was achieved. Additionally, the method was shown to be linear-scaling for a conjugated polymer for system sizes up to 1000 atoms. The use of the projection method was shown to be crucial for calculating the above results, as was the implementation of a momentum operator based formalism for the calculation of spectra. Finally, it was shown that the method can be used to identify the transitions responsible for particular peaks in the spectra and is sensitive enough to distinguish between spectra for systems with very similar structures, demonstrating the capabilities of the method to aid the interpretation of experimental results

A predictive model of criminality in civil psychiatric populations

Purpose The purpose of this paper is to develop a predictive model of criminal risk in civil psychiatric populations, by determining the relative impacts of psychopathy, drug use, impulsivity and intelligence on levels of criminality. Design/methodology/approach The sample consisted of 871 civil psychiatric patients, selected from the MacArthur Violence Risk Assessment Study, who had been diagnosed with a mental illness or personality disorder, and hospitalised less than 21 days. Each participant was administered the Hare Psychopathy Checklist Screening Version (PCL:SV), Barratt Impulsiveness Scale (BIS-11) and the Wechsler Adult Intelligence Scale (WAIS-R). In addition, information on background demographics, drug use and criminality was obtained via a self-report questionnaire. Findings Pearson correlations identified significant positive relationships between past arrests, psychopathy, impulsivity and drug use. Intelligence was negatively related to past arrests. Multiple regressions identified a significant main effect for Factor 2 psychopathy on past arrests when controlling for all covariates, but not for Factor 1 psychopathy, intelligence or impulsivity. Drug use and gender had small univariate effects. Research limitations/implications It is suggested that future research investigates the influence of specific mental disorders on different types of offending. Originality/value By investigating predictors of criminal behaviour in civil psychiatric patients, the present study makes valuable contributions to the research literature, enhancing our theoretical understanding of the relationships between psychopathy and criminality/recidivism. It also has notable implications in applied practice, for example in the development and refinement of risk assessment methods

Galectin-1 in myelin repair

Galectin-1 (Gal-1) is a member of a highly conserved family of animal lectins which binds to the common disaccharide [Galβ(1-4)-GlcNAc] on both N- and O-glycans decorating cell surface glycoconjugates. Current evidence supports a role for Gal-1 in the pathophysiology of multiple sclerosis (MS), one of the most prevalent chronic inflammatory diseases, as approximately one third of MS patients generate high titres of anti-Gal-1 antibodies. Four different lesion types have been described in MS: pattern-1 and -2 lesions are thought to be mediated by the autoimmune response, while pattern-3 and -4 lesions are considered primary oligodendropathy. The first two types are experimentally simulated in mice by experimental autoimmune encephalomyelitis (EAE), while the second two are mimicked by toxic models such as cuprizone (CPZ) or lysolecithin (LPC) administration. Studies in EAE models have demonstrated that Gal-1 is highly expressed in the acute phase of the disease and that its deficiency leads to severe inflammation-induced neurodegeneration [1]. Regarding its mechanism of action,Fil: Rinaldi, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; ArgentinaFil: Thomas, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; ArgentinaFil: Pasquini, Laura Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; Argentin

The meditative mind: a comprehensive meta-analysis of MRI studies

Over the past decade mind and body practices, such as yoga and meditation, have raised interest in different scientific fields; in particular, the physiological mechanisms underlying the beneficial effects observed in meditators have been investigated. Neuroimaging studies have studied the effects of meditation on brain structure and function and findings have helped clarify the biological underpinnings of the positive effects of meditation practice and the possible integration of this technique in standard therapy. The large amount of data collected thus far allows drawing some conclusions about the neural effects of meditation practice. In the present study we used activation likelihood estimation (ALE) analysis to make a coordinate-based meta-analysis of neuroimaging data on the effects of meditation on brain structure and function. Results indicate that meditation leads to activation in brain areas involved in processing self-relevant information, self-regulation, focused problem-solving, adaptive behavior, and interoception. Results also show that meditation practice induces functional and structural brain modifications in expert meditators, especially in areas involved in self-referential processes such as self-awareness and self-regulation. These results demonstrate that a biological substrate underlies the positive pervasive effect of meditation practice and suggest that meditation techniques could be adopted in clinical populations and to prevent disease

Safety, Security and Socio-Economic Wellbeing in Somaliland

This report documents the findings from a study on the relationship between safety/security and socio-economic wellbeing in Somaliland. The study was conducted for the Danish Demining Group (DDG) and Geneva International Centre for Humanitarian Demining in twelve of DDG's project sites. It is based on a quantitative survey of 378 households and qualitative focus group interviews. Findings suggest a high degree of correlation between improvements in safety and security, many associated with the community safety work of DDG, and socio-economic benefits to communities. Reported benefits include fewer conflicts, more secure communities at night, fewer accidents involving small arms and explosive remnants of war, and better community-police relations. These are perceived to have contributed to improvements in access to markets, lengthening hours that businesses can remain open, improved opportunities for participating in savings activities, and generally increased household incomes. Recommendations for maximizing the benefits of improved security for socio-economic gains are provided

Inflation targeting and product market deregulation : [Version Januar 2012]

I evaluate the effect of inflation targeting on inflation and how it interacts with product market deregulation during the disinflationary process in the 1990s. Using a sample of 21 OECD countries, I show that, after controlling for product market deregulation, the effect of inflation targeting is quantitatively important and statistically significant. Moreover, product market deregulation also matters in particular in countries that adopted an inflation targeting regime. I propose a New Keynesian Phillips curve with an explicit role for market deregulation to rationalize the empirical evidence

A declarative characterization of different types of multicomponent tree adjoining grammars

Multicomponent Tree Adjoining Grammars (MCTAG) is a formalism that has been shown to be useful for many natural language applications. The definition of MCTAG however is problematic since it refers to the process of the derivation itself: a simultaneity constraint must be respected concerning the way the members of the elementary tree sets are added. This way of characterizing MCTAG does not allow to abstract away from the concrete order of derivation. In this paper, we propose an alternative definition of MCTAG that characterizes the trees in the tree language of an MCTAG via the properties of the derivation trees (in the underlying TAG) the MCTAG licences. This definition gives a better understanding of the formalism, it allows a more systematic comparison of different types of MCTAG, and, furthermore, it can be exploited for parsing