20,688 research outputs found
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
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
Unbounded entanglement in nonlocal games
Quantum entanglement is known to provide a strong advantage in many two-party
distributed tasks. We investigate the question of how much entanglement is
needed to reach optimal performance. For the first time we show that there
exists a purely classical scenario for which no finite amount of entanglement
suffices. To this end we introduce a simple two-party nonlocal game ,
inspired by Lucien Hardy's paradox. In our game each player has only two
possible questions and can provide bit strings of any finite length as answer.
We exhibit a sequence of strategies which use entangled states in increasing
dimension and succeed with probability for some .
On the other hand, we show that any strategy using an entangled state of local
dimension has success probability at most . In addition,
we show that any strategy restricted to producing answers in a set of
cardinality at most has success probability at most .
Finally, we generalize our construction to derive similar results starting from
any game with two questions per player and finite answers sets in which
quantum strategies have an advantage.Comment: We have removed the inaccurate discussion of infinite-dimensional
strategies in Section 5. Other minor correction
Quiet No More: Philadelphia Confronts the Cost of Employee Benefits
Examines the financial difficulties Philadelphia's pension and healthcare benefits system faces due the stock market decline and rising healthcare costs in comparison with those of nine other cities' systems. Analyzes proposed restructuring plans
On Income Inequality and Green Preferences
We derive conditions on individual preferences and technology that give rise to a negative correlation between income inequality and environmental protection. We present a class of models (which captures a static model as well as an overlapping-generations model) in which individuals differ in earning abilities, and where a majority elected representative takes decisions over a pollution tax and a redistributive tax. We show that, if private consumption goods and the environment are non-inferior goods, then if the decisive individual has lower ability than the average, she will prefer a higher redistributive tax and a lower pollution tax.Environmental policy, redistribution, inequality, political economy
Inequality, Environmental Protection and Growth
We analyze how, in representative democracies, income distribution influences the stringency of environmental policy and economic growth. Individuals (who differ in abilities) live for two periods, working when young and owning capital when old. Externalities are caused by a polluting factor. The revenue from pollution taxation, as well as capital-income taxation, is redistributed lump-sum to the old. The fiscal decision, at each point in time, is taken by a majority elected representative. In politico-economic equilibrium, more inequality (in terms of the skewness of the distribution) yields a lower pollution tax, a larger capital tax, and lower growth.Environmental policy, redistribution, inequality, political economy, growth.
Multi-View Video Packet Scheduling
In multiview applications, multiple cameras acquire the same scene from
different viewpoints and generally produce correlated video streams. This
results in large amounts of highly redundant data. In order to save resources,
it is critical to handle properly this correlation during encoding and
transmission of the multiview data. In this work, we propose a
correlation-aware packet scheduling algorithm for multi-camera networks, where
information from all cameras are transmitted over a bottleneck channel to
clients that reconstruct the multiview images. The scheduling algorithm relies
on a new rate-distortion model that captures the importance of each view in the
scene reconstruction. We propose a problem formulation for the optimization of
the packet scheduling policies, which adapt to variations in the scene content.
Then, we design a low complexity scheduling algorithm based on a trellis search
that selects the subset of candidate packets to be transmitted towards
effective multiview reconstruction at clients. Extensive simulation results
confirm the gain of our scheduling algorithm when inter-source correlation
information is used in the scheduler, compared to scheduling policies with no
information about the correlation or non-adaptive scheduling policies. We
finally show that increasing the optimization horizon in the packet scheduling
algorithm improves the transmission performance, especially in scenarios where
the level of correlation rapidly varies with time
Asbestos Neglect: Why Asbestos Exposure Deserves Greater Policy Attention
While many public health threats are now widely appreciated by the public, the risks from asbestos exposure remain poorly understood, even in high-risk groups. This article makes the case that asbestos exposure is an important, ongoing global health threat, and argues for greater policy efforts to raise awareness of this threat. It also proposes the extension of asbestos bans to developing countries and increased public subsidies for asbestos testing and abatement
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