Deprivation-induced plasticity of sensory cortical maps involves long-term potentiation (LTP) and depression (LTD) of cortical synapses, but how sensory deprivation triggers LTP and LTD in vivo is ...unknown. Here we tested whether spike timing-dependent forms of LTP and LTD are involved in this process. We measured spike trains from neurons in layer 4 (L4) and layers 2 and 3 (L2/3) of rat somatosensory cortex before and after acute whisker deprivation, a manipulation that induces whisker map plasticity involving LTD at L4-to-L2/3 (L4-L2/3) synapses. Whisker deprivation caused an immediate reversal of firing order for most L4 and L2/3 neurons and a substantial decorrelation of spike trains, changes known to drive timing-dependent LTD at L4-L2/3 synapses in vitro. In contrast, spike rate changed only modestly. Thus, whisker deprivation is likely to drive map plasticity by spike timing-dependent mechanisms.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
ABSTRACT
The Mef2B gene (myocyte enhancer factor 2B) encodes a transcription factor belonging to the MEF2 family that plays an important role in myogenesis by transcriptional regulation of genes ...involved in skeletal muscle growth and development. Despite the established importance of the Mef2 factors in the muscular growth and development, the temporal-spatial expression and biological function of Mef2B have not been reported in cattle. The aim of this study was to analyze the level of Mef2B expression in the developing longissimus dorsi muscle (LM) of 4 cattle breeds (Polish Holstein-Friesian HF, Limousine LIM, Hereford HER, Polish Red PR), differing in terms of meat production and utility type, at 6, 9, and 12 mo of age. The Mef2B genetic polymorphism and expression patterns in 6 tissues (heart, spleen, liver, semitendinosus muscle ST, gluteus medius muscle GM, and LM) were also investigated. The results showed that Mef2B mRNA was expressed at a high level in adult skeletal and cardiac muscles. Moreover, Mef2B expression was markedly greater in the GM than in the LM (P < 0.05) and ST (P < 0.01). An age-dependent and breed-specific comparison of Mef2B mRNA level in skeletal muscle of HF, LIM, HER, and PR bulls showed that age was significant differentiating factor of Mef2B transcript/protein abundance in the LM of HER and LIM (P < 0.001) compared to HF and PR, for which the differences in Mef2B mRNA level were not significant (P > 0.05). Regarding the breed effect on the Mef2B expression, significantly greater Mef2B mRNA/protein level was noticed in the LM of 9 and 12 mo-old HER than of LIM (P < 0.01), HF (P < 0.001), and PR (P < 0.001). Four novel SNP, namely, HQ591462:g.909A > G (promoter), JX065116:g.3867T > C (exon 7), JX065116:g.4359G > C (exon 8), and JX065116:g.4546G > A (3'UTR), were identified. We found that Mef2B 3'UTR variant, situated within the seed region of the miR-5187–3p and miR-6931–5p binding sites, was associated with the level of Mef2B mRNA/protein in LM of 12-mo-old HF bulls. In addition, we observed a significant association between some carcass quality traits, including meat and carcass fatness quality traits, and various Mef2B 3'UTR genotypes in the investigated population of HF cattle. Our finding provides new evidence of the Mef2B significant role in the postnatal muscle growth and development in cattle, and indicates that Mef2B can be a promising molecular marker for carcass quality-related traits in adult cattle.
The ALICE High-Level Trigger (HLT) has a large high-performance computing cluster at CERN whose main objective is to perform real-time analysis on the data generated by the ALICE experiment and scale ...it down to at-most 4GB/sec - which is the current maximum mass-storage bandwidth available. Data-flow in this cluster is controlled by a custom designed software framework. It consists of a set of components which can communicate with each other via a common control interface. The software framework also supports the creation of different configurations based on the detectors participating in the HLT. These configurations define a logical data processing “chain” of detector data-analysis components. Data flows through this software chain in a pipelined fashion so that several events can be processed at the same time. An instance of such a chain can run and manage a few thousand physics analysis and data-flow components. The HLT software and the configuration scheme used in the 2011 heavy-ion runs of ALICE, has been discussed in this contribution.
The High Level Trigger (HLT) system of the ALICE experiment is an online event filter and trigger system designed for input bandwidths of up to 25 GB/s at event rates of up to 1 kHz. The system is ...designed as a scalable PC cluster, implementing several hundred nodes. The transport of data in the system is handled by an object-oriented data flow framework operating on the basis of the publisher-subscriber principle, being designed fully pipelined with lowest processing overhead and communication latency in the cluster. In this paper, we report the latest measurements where this framework has been operated on five different sites over a global north-south link extending more than 10,000 km, processing a ldquoreal-timerdquo data flow.
The ALICE High Level Trigger comprises a large computing cluster, dedicated interfaces and software applications. It allows on-line event reconstruction of the full data stream of the ALICE ...experiment at up to 25 GByte/s. The commissioning campaign has passed an important phase since the startup of the Large Hadron Collider in November 2009. The system has been transferred into continuous operation with focus on the event reconstruction and first simple trigger applications. The paper reports for the first time on the achieved event reconstruction performance in the ALICE central barrel region.
The Mef2B gene (myocyte enhancer factor 2B) encodes a transcription factor belonging to the MEF2 family that plays an important role in myogenesis by transcriptional regulation of genes involved in ...skeletal muscle growth and development. Despite the established importance of the Mef2 factors in the muscular growth and development, the temporal-spatial expression and biological function of Mef2B have not been reported in cattle. The aim of this study was to analyze the level of Mef2B expression in the developing longissimus dorsi muscle (LM) of 4 cattle breeds (Polish Holstein-Friesian HF, Limousine LIM, Hereford HER, Polish Red PR), differing in terms of meat production and utility type, at 6, 9, and 12 mo of age. The Mef2B genetic polymorphism and expression patterns in 6 tissues (heart, spleen, liver, semitendinosus muscle ST, gluteus medius muscle GM, and LM) were also investigated. The results showed that Mef2B mRNA was expressed at a high level in adult skeletal and cardiac muscles. Moreover, Mef2B expression was markedly greater in the GM than in the LM (P < 0.05) and ST (P < 0.01). An age-dependent and breed-specific comparison of Mef2B mRNA level in skeletal muscle of HF, LIM, HER, and PR bulls showed that age was significant differentiating factor of Mef2B transcript/protein abundance in the LM of HER and LIM (P < 0.001) compared to HF and PR, for which the differences in Mef2B mRNA level were not significant (P > 0.05). Regarding the breed effect on the Mef2B expression, significantly greater Mef2B mRNA/protein level was noticed in the LM of 9 and 12 mo-old HER than of LIM (P < 0.01), HF (P < 0.001), and PR (P < 0.001). Four novel SNP, namely, HQ591462:g.909A > G (promoter), JX065116:g.3867T > C (exon 7), JX065116:g.4359G > C (exon 8), and JX065116:g.4546G > A (3'UTR), were identified. We found that Mef2B 3'UTR variant, situated within the seed region of the miR-5187-3p and miR-6931-5p binding sites, was associated with the level of Mef2B mRNA/protein in LM of 12-mo-old HF bulls. In addition, we observed a significant association between some carcass quality traits, including meat and carcass fatness quality traits, and various Mef2B 3'UTR genotypes in the investigated population of HF cattle. Our finding provides new evidence of the Mef2B significant role in the postnatal muscle growth and development in cattle, and indicates that Mef2B can be a promising molecular marker for carcass quality-related traits in adult cattle.
Deformation analysis of any type of a deformable body includes geometrical analysis and physical interpretation. The ultimate goal of the geometrical analysis is to determine in the whole deformable ...object the displacement and strain fields in the space and time domains. Physical interpretation is to establish the relationship between the causative factors (loads) and the deformations. The latter may be obtained by deterministic modelling of deformations using, for example, finite element method (FEM). By comparing the geometrical and deterministic model of deformations, one can verify the designed behaviour of the deformable object. In addition, with properly designed monitoring surveys, one may also determine the actual deformation mechanism and explain causes of deformation in a case of unexpected behaviour of the investigated object. Thus, the role of deformation monitoring surveys becomes much broader than just the conventional determination of the geometrical status of the deformable object.
In this presentation two examples are given on the use of geodetic monitoring surveys in the
(a)
determination of effects of hydrological changes on ground subsidence in a potash mine in Canada and
(b)
verification of geomechanical parameters of a large earth dam in California during the filling up of the water reservoir.
The ALICE High Level Trigger combines and processes the full information from all major detectors in a large computer cluster. Data rate reduction is achieved by reducing the event rate by selecting ...interesting events (software trigger) and by reducing the event size by selecting sub-events and by advanced data compression. Reconstruction chains for the barrel detectors and the forward muon spectrometer have been benchmarked. The HLT receives a replica of the raw data via the standard ALICE DDL link into a custom PCI receiver card (HLT-RORC). These boards also provide a FPGA co-processor for data-intensive tasks of pattern recognition. Some of the pattern recognition algorithms (cluster finder, Hough transformation) have been re-designed in VHDL to be executed in the Virtex-4 FPGA on the HLT-RORC. HLT prototypes were operated during the beam tests of the TPC and TRD detectors. The input and output interfaces to DAQ and the data flow inside of HLT were successfully tested. A full-scale prototype of the dimuon-HLT achieved the expected data flow performance. This system was finally embedded in a GRID-like system of several distributed clusters demonstrating the scalability and fault-tolerance of the HLT.
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