1,009 research outputs found
Evidence for the existence of homolateral and contralateral projections from the substantia nigra to the subthalamic nucleus in the rat
Hemichorea/ballism is a rare neurological disorder but the crucial involvement of the subthalamic nucleus (STN) in its pathophysiology is appreciated since decades. The idiopathic Parkinsonâs disease is a common neurodegenerative disorder but the key role of the STN in the pathophysiological origin of the parkinsonian state became only recently evident. The STN was believed to exert an inhibitory, probably â GABA-mediated, effect on its projection nuclei, and this belief is one of the major reasons to overlook the involvement of the STN in the parkinsonian pathophysiology. It is now firmly established that the STN projection neurons are glutamatergic, excitatory, and heavily innervate by widely branching axons of the substantia nigra (SN), the internal pallidal segment (GPI), followed by the external pallidal segment (GPE) and the pedunculopontine tegmental nucleus (PPN)
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USP2a alters chemotherapeutic response by modulating redox
Cancer cells are characterized by altered ubiquitination of many proteins. The ubiquitin-specific protease 2a (USP2a) is a deubiquitinating enzyme overexpressed in prostate adenocarcinomas, where it exhibits oncogenic behavior in a variety of ways including targeting c-Myc via the miR-34b/c cluster. Here we demonstrate that USP2a induces drug resistance in both immortalized and transformed prostate cells. Specifically, it confers resistance to typically pro-oxidant agents, such as cisplatin (CDDP) and doxorubicin (Doxo), and to taxanes. USP2a overexpression protects from drug-induced oxidative stress by reducing reactive oxygen species (ROS) production and stabilizing the mitochondrial membrane potential (ÎΚ), thus impairing downstream p38 activation and triggering of apoptosis. The molecular mediator of the USP2a protective function is the glutathione (GSH). Through miR-34b/c-driven c-Myc regulation, USP2a increases intracellular GSH content, thus interfering with the oxidative cascade triggered by chemotherapeutic agents. In light of these findings, targeting Myc and/or miR-34b/c might revert chemo-resistance
Delay-induced rebounds in CO_{2} emissions and critical time-scales to meet global warming targets
While climate science debates are focused on the attainment of peak anthropogenic CO2 emissions and policy tools to reduce peak temperatures, the humanâenergyâclimate system can hold âreboundâ surprises beyond this peak. Following the second industrial revolution, global per capita CO_{2} emissions (c_{c}) experienced a punctuated growth of about 100% every 60âyears, mainly attributable to technological development and its global spread. A model of the humanâenergyâclimate system capable of reproducing past punctuated dynamics shows that rebounds in global CO_{2} emissions emerge due to delays intrinsic to the diffusion of innovations. Such intrinsic delays in the adoption and spread of lowâcarbon emitting technologies, together with projected population growth, upset the warming target set by the Paris Agreement. To avoid rebounds and their negative climate effects, model calculations show that the diffusion of climateâfriendly technologies must occur with lags oneâorder of magnitude shorter (i.e., âŒ6âyears) than the characteristic timescale of past punctuated growth in c_{c}. Radically new strategies to globally implement the technological advances at unprecedented rates are needed if the current emission goals are to be achieved
The Spaces of Social Services as Social Infrastructure: Insights From a PolicyâInnovation Project in Milan
The spatial organisation of social services has long been residual for both urban planning and social welfare policies in Italian cities. This often results in randomly chosen locations and poor design arrangements, which ignore the role that space might play in fostering social life and inclusion. The scarce relevance given to the topic both in research and implementation is connected to the historical evolution of social services in the country and the scant resources devoted to their provision. Basing itself on the debate on welfare spaces and social infrastructures and drawing on a collaborativeâresearch experience within an experimental policyâinnovation project developed in Milan, this article tackles the role of space in social services provision following three directions. Firstly, it analyses how, at the urban level, welfare innovations and the interplay between urban planning and welfare policies might contribute to reshaping the traditional physical structures of social services and their map to favour more inclusive patterns of access to local welfare. Secondly, it investigates the role of social services as social infrastructures in increasing accessibility, reducing stigmatisation, and interpreting in a more inclusive way the complex publicâprivate partnerships that allow welfare implementation nowadays. Finally, it discusses how, in the face of contemporary trends in the activation of welfare spaces, traditional urban planning tools are challenged in monitoring their increasingly dynamic distribution in the city. This highlights the need to develop innovative urban planning strategies and tools to effectively support decisionâmaking and design
K+ conductance of mechanically dissociated rat sensory neurones in long lerm cultures in a defined medium
LIDAR DERIVED SALT MARSH TOPOGRAPHY AND BIOMASS: DEFINING ACCURACY AND SPATIAL PATTERNS OF UNCERTAINTY
As valuable and vulnerable blue carbon ecosystems, salt marshes require adaptable and robust monitoring methods that span a range of spatiotemporal scales. The application of unmanned aerial vehicle (UAV) based remote sensing is a key tool in achieving this goal. Due to the particular characteristics of tidal wetlands, however, there are challenges in obtaining research and management relevant data with the requisite level of accuracy. In this study, the spatial patterns in uncertainty stemming from scan angle, binning method, vegetation structure and platform surface morphology are examined in the context of UAV light detection and ranging (LiDAR) derived digital elevation models (DEM). The results demonstrate that overlapping the UAV flight paths sufficiently to avoid sole reliance on LIDAR data with scan angles exceeding 15 degrees is advisable. Furthermore, the spatial arrangement of halophyte species and marsh morphology has a clear influence on DEM accuracy. The largest errors were associated with sudden structural transitions at the marsh channel boundaries. The DEMmean was found to be the most accurate for bare ground, while the DEMmin was the most accurate for channels and the middle to high marsh vegetation (MAEs = â0.01m). For the low to middle vegetation, all the trialled DEMs returned a similar magnitude of mean error (MAE = ±â0.03m). The accuracy difference between the two vegetation associations examined appears to be connected to variations in coverage, height and biomass. Overall, these findings reinforce the link between salt marsh biogeomorphic complexity and the spatial distribution and magnitude of LiDAR DEM erro
Optical and evaporative cooling of cesium atoms in the gravito-optical surface trap
We report on cooling of an atomic cesium gas closely above an evanescent-wave
atom mirror. At high densitities, optical cooling based on inelastic
reflections is found to be limited by a density-dependent excess temperature
and trap loss due to ultracold collisions involving repulsive molecular states.
Nevertheless, very good starting conditions for subsequent evaporative cooling
are obtained. Our first evaporation experiments show a temperature reduction
from 10muK down to 300nK along with a gain in phase-space density of almost two
orders of magnitude.Comment: 8 pages, 6 figures, submitted to Journal of Modern Optics, special
issue "Fundamentals of Quantum Optics V", edited by F. Ehlotzk
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