Activation by S-adenosylhomocysteine of norepinephrine and serotonin in vitro uptake in synaptosomal preparations from rat brain.

S-Adenosylhomocysteine (10(-7)-10(-5) M) activated norepinephrine (NE) and serotonin (5HT) in vitro uptake in synaptosomal preparations from rat brain, but did not affect dopamine (DA) uptake. When administered to rats (7 mg/kg i.p.), it has the same effect on in vitro NE and 5HT uptake. It did not affect NE and 5HT release.     

Systemic Analysis of the Brazilian Production Chain of Semiconductors: Graphic Representation and Leverage Points

The purpose of this article is to analyze systemically the Brazilian production chain of semiconductors. The specific objectives of this article are to represent the chain systemically and to identify key variables and leverage points that can increase the overall performance of the semiconductor industry. The research method is qualitative modelling. Eleven practitioners of the industry answered a questionnaire approaching various aspects of the semiconductor industry in Brazil. By a systemic approach, the complex behavior present in the industry was considered. By content analysis, we identified patterns in the speech of the respondents. Texts fragments allowed the identification of key themes and variables present in the system. The association among key variables and complex behavior helped to build a systemic structure, aimed at representing the main relationships in the system. From the systemic structure, eight leverage points were identified and discussed. The key implications of the findings are the damage that cheap imports make in the local market; the need of strong public policies that include more than tax reduction, but also local conditions, like clusters or technological parks, for the high-tech manufacture; and the promotion of conditions that stimulate private investment in the industry.     

Allosteric function and dysfunction of the prion protein

Transmissible spongiform encephalopathies (TSEs) are neurodegenerative diseases associated with progressive oligo- and multimerization of the prion protein (PrP^C), its conformational conversion, aggregation and precipitation. We recently proposed that PrP^C serves as a cell surface scaffold protein for a variety of signaling modules, the effects of which translate into wide-range functional consequences. Here we review evidence for allosteric functions of PrP^C, which constitute a common property of scaffold proteins. The available data suggest that allosteric effects among PrP^C and its partners are involved in the assembly of multi-component signaling modules at the cell surface, impose upon both physiological and pathological conformational responses of PrP^C, and that allosteric dysfunction of PrP^C has the potential to entail progressive signal corruption. These properties may be germane both to physiological roles of PrP^C, as well as to the pathogenesis of the TSEs and other degenerative/non-communicable diseases.     

De novo mutations in ATP1A3 cause alternating hemiplegia of childhood

Alternating hemiplegia of childhood (AHC) is a rare, severe neurodevelopmental syndrome characterized by recurrent hemiplegic episodes and distinct neurological manifestations. AHC is usually a sporadic disorder and has unknown etiology. We used exome sequencing of seven patients with AHC and their unaffected parents to identify de novo nonsynonymous mutations in ATP1A3 in all seven individuals. In a subsequent sequence analysis of ATP1A3 in 98 other patients with AHC, we found that ATP1A3 mutations were likely to be responsible for at least 74% of the cases; we also identified one inherited mutation in a case of familial AHC. Notably, most AHC cases are caused by one of seven recurrent ATP1A3 mutations, one of which was observed in 36 patients. Unlike ATP1A3 mutations that cause rapid-onset dystonia-parkinsonism, AHC-causing mutations in this gene caused consistent reductions in ATPase activity without affecting the level of protein expression. This work identifies de novo ATP1A3 mutations as the primary cause of AHC and offers insight into disease pathophysiology by expanding the spectrum of phenotypes associated with mutations in ATP1A3.     

Systemic Understanding of Coopetitive Behaviour in a Latin American Technological Park

The purpose of this article is to construct a systemic structure to explain the relations subjacent to the coopetitive behaviour observed in a Latin American technological park. The research method is qualitative modelling. The primary research technique is the in-depth interview with park experts. Systemic language organised the speeches. The systemic language uses symbols that represent the elements of a system, such as variables, relations, and feedback loops. Initially, we constructed two essential archetypes that describe how the need for coopetition emerged, triggered by failures in meeting customers´ demands and reduced sales. Then, we built an overall systemic structure relying on the essential archetypes, which explains how the coopetitive strategy emerged in the park. The main conclusion reached by the study is learning and public policies as desirable conditions; failure in meeting customers’ requirements as the trigger; and sustainability, knowledge and resource sharing, mitigation of risks and uncertainties, and increased sales by price reduction, as reinforcing feedback factors. The main contribution of the study is a systemic qualitative model that helps understanding how to implement or manage a coopetitive strategy in a network formed of companies mainly driven by technological factors.     

Nucleolar localization and circadian regulation of Per2S,a novel splicing variant of the Period 2 gene

In this work, we show for the first time that a second splicing variant of the core clock gene Period 2 (Per2), Per2S, is expressed at both the mRNA and protein levels in human keratinocytes and that it localizes in the nucleoli. Moreover, we show that a reversible perturbation of the nucleolar structure acts as a resetting stimulus for the cellular clock. Per2S expression and periodic oscillation upon dexamethasone treatment were assessed by qRT-PCR using specific primers. Western blot (WB) analysis using an antibody against the recombinant human PER2 (abRc) displayed an intense band at a molecular weight of ~55 kDa, close to the predicted size of Per2S, and a weaker band at the expected size of Per2 (~140 kDa). The antibody raised against PER2 pS662 (abS662), an epitope absent in PER2S, detected only the higher band. Immunolocalization studies with abRc revealed a peculiar nucleolar signal colocalizing with the nucleolar marker nucleophosmin, whereas with abS662 the signal was predominantly diffuse all over the nucleus and partially colocalized with abRc in the nucleolus. The analysis of cell fractions by WB confirmed the enrichment of PER2S and the presence of PER2 in the nucleolar compartment. Finally, a pulse (1 h) of actinomycin D (0.01 μg/ml) induced reversible nucleolar disruption, PER2S de-localization and circadian synchronization of clock and Per2S genes. Our work represents the first evidence that the Per2S splicing isoform is a clock component expressed in human cells localizing in the nucleolus. These results suggest a critical role for the nucleolus in the process of circadian synchronization in human keratinocytes.     

South American SLR stations monitoring ground displacement caused by the M8.8 Chilean earthquake of 2010

The M8.8 Chilean earthquake of February 27, 2010 caused a large surface displacement near its epicenter. Satellite Laser Ranging (SLR) station 7405, cooperatively operated by Germany and Chile about 130 km from the epicenter was affected by the earthquake. Another SLR station, No. 7406, operated jointly by the National Astronomical Observatories of the Chinese Academy of Sciences and San Juan University of Argentina, was about 600 km from the epicenter. Combining the observations of these two SLR stations with global SLR station observations, we calculate the geocentric coordinates of the two stations based on ITRF2000. The results show that the coordinates of the two stations have changed by varying degrees. SLR-7405 moved substantially towards the southwest with displacements of about 3.11, 0.52 and 0.49 m in X, Y, Z directions; the corresponding displacements for SLR-7406 are about 0.02, 0.03 and 0.02 m. This solution, as an independent result derived from SLR observations, could provide an essential external check for other positioning techniques such as GPS.