Relation between the properties of the kilohertz quasi-periodic oscillations and spectral parameters in 4U 1636−-53

We investigate the relation between the parameters of the energy spectrum and the frequency and amplitude of the kilohertz quasi-periodic oscillations (kHz QPOs) in the low-mass X-ray binary 4U 1636$-$53. We fit the $3-180$-keV spectrum of this source with a model that includes a thermal Comptonisation component. We show that the frequencies of both kHz QPOs follow the same relation as a function of the parameters of this spectral component, except for a systematic frequency shift, whereas the rms fractional amplitude of each QPO follows a different relation with respect to those same parameters. This implies that, while the dynamical mechanism that sets the frequencies of the QPO can be the same for both kHz QPOs, the radiative mechanisms that set the amplitudes of the lower and the upper kHz QPO are likely different. We discuss the implications of these results to the modelling of the kHz QPOs and the possibility that the lower kHz QPO reflects a resonance between the Comptonising medium and the photons from the accretion disc and/or the neutron star surface.Comment: 7 pages, 4 figures, 2 tables. Accepted for publication in MNRA

Effect of dsRNA on Mesangial Cell Synthesis of Plasminogen Activator Inhibitor Type 1 and Tissue Plasminogen Activator

Background/Aims: Viral infections are a major problem worldwide and many of them are complicated by virally induced glomerulonephritides. Progression of kidney disease to renal failure is mainly attributed to the development of renal fibrosis characterized by the accumulation of extracellular matrix components in the mesangial cell compartment and the glomerular basement membrane. Plasminogen activator inhibitor type 1 (PAI-1) and tissue plasminogen activator (t-PA) are major regulators of plasmin generation and play an important role in generation and degradation of glomerular extracellular matrix components. Viral receptors expressed by mesangial cells (MC) are known to be key mediators in immune-mediated glomerulonephritis. We investigated the effect of stimulation of the viral receptors toll-like receptor 3 (TLR3) and retinoic acid-inducible gene I (RIG-I) on the expression of PAI-1 and t-PA. Methods: Expression of PAI-1 and t-PA in immortalized human MC stimulated with polyriboinosinic: polyribocytidylic acid {[}poly(I:C)] RNA and cytokines were analyzed by real-time RT-PCR and ELISA. Results: Incubation of MC with poly(I:C) RNA to activate the viral receptors TLR3 and RIG-I upregulates the expression of PAI-1 and t-PA. Knockdown of viral receptors with specific siRNA abolishes the induction of PAI-1 and t-PA. Conclusion: For the first time a link between the activation of viral receptors on MC and potentially causative agents in the development of glomerulosclerosis and tubulointerstitial fibrosis is shown. The progression of inflammatory processes to glomerulosclerosis can be postulated to be directly enhanced by viral infection. Copyright (C) 2009 S. Karger AG, Base

A more cooperative EU policy towards MERCOSUR? The case of foreign direct investment (1980-2000)

In the light of the negotiations of the bi-regional framework agreement between the European Union and MERCOSUR signed in 1995, this paper inquires whether the European Union foreign policy towards MERCOSUR has become more cooperative in the last decades, and offers an explanation to this question based in a case-study regarding foreign direct investment.À luz das negociações do tratado quadro birregional entre a União Europeia e o Mercosul assinado em 1995, este artigo explora em que medida a política externa da União Europeia relativamente ao Mercosul se tem tornado mais cooperativa nas últimas décadas, e fornece uma explicação baseada num estudo de caso que envolve o investimento estrangeiro directo

Relation between spectral changes and the presence of the lower kHz QPO in the neutron-star low-mass X-ray binary 4U 1636-53

We fitted the $3-180$-keV spectrum of all the observations of the neutron-star low-mass X-ray binary 4U 1636$-$53 taken with the {\it Rossi X-ray Timing Explorer} using a model that includes a thermal Comptonisation component. We found that in the low-hard state the power-law index of this component, $\Gamma$, gradually increases as the source moves in the colour-colour diagram. When the source undergoes a transition from the hard to the soft state $\Gamma$ drops abruptly; once the source is in the soft state $\Gamma$ increases again and then decreases gradually as the source spectrum softens further. The changes in $\Gamma$, together with changes of the electron temperature, reflect changes of the optical depth in the corona. The lower kilohertz quasi-periodic oscillation (kHz QPO) in this source appears only in observations during the transition from the hard to the soft state, when the optical depth of the corona is high and changes depends strongly upon the position of the source in the colour-colour diagram. Our results are consistent with a scenario in which the lower kHz QPO reflects a global mode in the system that results from the resonance between, the disc and/or the neutron-star surface, and the Comptonising corona.Comment: 9 pages, 6 figures. Accepted for publication in MNRA

HUMERAL RETROVERSION IN OVERHEAD THROWING ATHLETES

The purpose of this study was to compare the dominant shoulder humeral retroversion of handball and volleyball players and a control group to understand if throwers show the same behaviour concerning humeral torsion. The dominant shoulder of 33 subjects (11 volleyball players, 11 handball players and 11 non-athletes) was submitted to a shoulder semiaxial radiograph in order to identify the humeral retroversion angle. Handball players showed significantly (p=0.03) less humeral retroversion than volleyball players which could be related with less external rotation range-of-motion found on previous studies. Volleyball players presented more retroversion angle, so more external rotation, allowing the correct alignment of the articular surfaces and glenohumeral stability, being able to have a cocking phase with more amplitude achieving maximal performance

Shoulder morphofunctional adaptations on overhead-throwing athletes : implications for physiotherapy throwing-shoulder examination.

Doutoramento em Motricidade Humana, especialidade de Ciências da Fisioterapia.The overhead throwing motion is a highly skilled movement, particularly demanding to the shoulder due to high strength levels and/or acceleration applied to the hand and by the elevated degree of control and precision required to position the arm in space. The shoulders of those involved in repeated forceful overhead throwing, the overhead-throwing athletes, undergo a range of neural, soft tissues and skeletal adaptations that could be described as, the “overhead-throwing shoulder adaptive pattern” (OTSAP). The main goal of overall studies in this thesis was to characterize the dominant overhead-throwing shoulder adaptive pattern of non-symptomatic overhead throwing athletes, comparing with a non-athletic population. Additionally, while comparing volleyball and team-handball players, we looked for specific sport-related components of the OTSAP. Knowledge on OTSAP is important for those involved on training, but also for sport physiotherapist during shoulder functional assessment. Some components of the OTSAP could be mistaken by injury signs or risk factors. Structural (osseous) and functional changes were identified on the dominant shoulder of volleyball and team-handball players. Some were similar of those described in baseball players, and others were sport-related. Thus, the OTSAP should be considered by the physiotherapist during overhead-throwing shoulder assessment. RESUMO:O movimento de lançamento é altamente especializado e particularmente exigente para o ombro devido aos excessivos níveis de carga/aceleração aplicados. Atletas cujos ombros estão envolvidos em movimentos repetidos de lançamento, consideram-se, na literatura anglo-saxónica, atletas “overhead”. Estes são sujeitos a um conjunto de adaptações neurais, tecidulares e ósseas que podem ser descritas como, o “padrão de adaptação do ombro do atleta overhead” (PAOAO). O principal objetivo da tese foi caracterizar o padrão de adaptação do ombro dominante, não sintomático, dos atletas “overhead”, comparando-os com não atletas. Adicionalmente, comparando voleibolistas e andebolistas, procurou-se encontrar componentes específicos da modalidade praticada inerentes ao PAOAO. O conhecimento detalhado deste PAOAO é crucial para os intervenientes em processos de treino, e para o fisioterapeuta responsável por uma avaliação detalhada do ombro, sob pena de alguns dos componentes do PAOAO serem erroneamente considerados como sinais de lesão ou fatores de risco. Foram identificadas alterações estruturais e funcionais no ombro dominante de voleibolistas e andebolistas. Algumas são similares às encontradas em jogadores de beisebol, enquanto outras estão diretamente relacionadas com a prática desportiva específica. Assim, este PAOAO deverá ser tido em consideração pelo fisioterapeuta aquando da avaliação do ombro do atleta “overhead”.FCT - Fundação para a Ciência e a Tecnologi

On the essence and initiality of conflicts

Understanding conflicts between transformations and rules is an important topic in algebraic graph transformation. A conflict occurs when two transformations are not parallel independent, that is, when after applying one of them the other can no longer occur. We contribute to this research thread by proposing a new characterization of the root causes of conflicts, called “conflict essences”. By exploiting a recently proposed characterization of parallel independence we easily show that the conflict essence of two transformations is empty iff they are parallel independent. Furthermore we show that conflict essences are smaller than the “conflict reasons” previously proposed, and that they uniquely determine the so-called “initial conflicts”. All results hold in categories of Set-valued functors, which include the categories of graphs and typed graphs, and several of them hold in the more general adhesive categories