An Apparent Paradox: Attenuation of Phenylephrine-mediated Calcium Mobilization and Hyperreactivity to Phenylephrine in Contralateral Carotid After Balloon Injury

Balloon catheter injury promotes hyperreactivity to phenylephrine (Phe) in the contralateral carotid. Phe-induced contraction involves calcium mobilization, a process that may be sensitive to reactive oxygen species. In this study, we investigated whether increased reactivity to Phe in the contralateral carotid is due to alterations in calcium mobilization by Phe and reactive oxygen species signaling. Concentration-response curves to Phe were obtained in control and contralateral arteries 4 days after balloon injury. Tiron did not modify E(max) to Phe in control arteries but reduced this parameter in the contralateral carotid to control levels. Moreover, immunofluorescence to dihydroethydine showed increased basal oxidative stress in the contralateral artery compared with control artery. Intracellular calcium mobilization by Phe in the contralateral artery was not different from control, but Phe-induced extracellular calcium mobilization was reduced in the contralateral artery compared with that in the control. These data were confirmed by confocal microscopy using Fluo 3-AM. Tiron and SC-236 increased Phe-induced calcium influx in the contralateral artery, which was similar to controls in the same conditions. However, catalase did not modify this response. Taken together, our results suggest that superoxide anions and prostanoids from cyclooxygenase-2 alter pathways downstream of alpha(1)-adrenoceptor activation in the contralateral carotid in response to injury. This results in reduced Phe-induced calcium influx, despite hyperreactivity to Phe.

Generation of nonground-state condensates and adiabatic paradox

The problem of resonant generation of nonground-state condensates is addressed aiming at resolving the seeming paradox that arises when one resorts to the adiabatic representation. In this picture, the eigenvalues and eigenfunctions of a time-dependent Gross-Pitaevskii Hamiltonian are also functions of time. Since the level energies vary in time, no definite transition frequency can be introduced. Hence no external modulation with a fixed frequency can be made resonant. Thus, the resonant generation of adiabatic coherent modes is impossible. However, this paradox occurs only in the frame of the adiabatic picture. It is shown that no paradox exists in the properly formulated diabatic representation. The resonant generation of diabatic coherent modes is a well defined phenomenon. As an example, the equations are derived, describing the generation of diabatic coherent modes by the combined resonant modulation of the trapping potential and atomic scattering length.

Development and Validation of a Mice liar Electrokinetic Chromatography Method for Quantitative Determination of Butenolides in Piper malacophyllum (C. Presl) C. DC.

Introduction - A large number of natural and synthetic compounds having butenolides as a core unit have been described and many of them display a wide range of biological activities. Butenolides from P. malacophyllum have presented potential antifungal activities but no specific, fast, and precise method has been developed for their determination. Objective - To develop a methodology based on micellar electrokinetic chromatography to determine butenolides in Piper species. Methodology - The extracts were analysed in an uncoated fused-silica capillaries and for the micellar system 20 mmol/L SDS, 20% (v/v) acetonitrile (ACN) and 10 mmol/L STB aqueous buffer at pH 9.2 were used. The method was validated for precision, linearity, limit of detection (LOD) and limit of quantitation (LOQ) and the standard deviations were determined from the standard errors estimated by the regression line. Results - A micellar electrokinetic chromatography (MEKC) method for determination of butenolides in extracts gave full resolution for 1 and 2. The analytical curve in the range 10.0-50.0 mu g/mL (r(2) = 0.999) provided LOD and LOQ for 1 and 2 of 2.1/6.3 and 1.1/3.5 mu g/mL, respectively. The RSD for migration times were 0.12 and 1.0% for peak area ratios with 100.0 +/- 1.4% of recovery. Conclusions - A novel high-performance MEKC method developed for the analysis of butenolides 1 and 2 in leaf extracts of P. malacophyllum allowed their quantitative determined within an analysis time shorter than 5 min and the results indicated CE to be a feasible analytical technique for the quantitative determination of butenolides in Piper extracts. Copyright (C) 2010 John Wiley & Sons, Ltd.

Da estratégia individual à ação coletiva: grupos de suporte e gênero no contexto da gestão da diversidade

Este artigo trata da formação de grupo de suporte no marco das políticas de diversidade empresarial. São escassas as pesquisas que abordem essa prática de gestão da diversidade. Visando a contribuir para o preenchimento dessa lacuna, o trabalho analisa um Comitê de Mulheres, a fim de compreender de que forma ele é influenciado pela política de diversidade formatada pela direção da organização e a influencia. Foi realizado um estudo de caso etnográfico em uma corporação transnacional cuja sede no Brasil está localizada em São Paulo. Os resultados apontam para um paradoxo. Por um lado, o Comitê analisado representa um processo de emancipação, sinalizando para práticas gerenciais mais inclusivas e participativas. Por outro, notou-se a presença de mecanismos de controle, uma vez que há um esforço da direção da empresa em disciplinar o seu funcionamento.

Sublimação e pulsão de morte: a desfusão pulsional

Com o advento do segundo dualismo pulsional freudiano, surge uma série de mudanças no entendimento da sublimação. Essa passa a se apresentar como a causa por excelência da desfusão das pulsões, o que nos leva a um paradoxo: ao mesmo tempo em que a sublimação é a base da cultura, ela é também causa da destrutividade no seio dessa mesma cultura. A pulsão de morte resultante da desfusão das pulsões, por sua vez, teria consequências tanto em cada indivíduo quanto na cultura como um todo, tal como o que se observa em relação ao primado da imagem na sociedade contemporânea. Este artigo busca discutir alguns dos efeitos da pulsão de morte desfusionada, entendida como resultado da sublimação, principalmente no que tange à sublimação implicada na criação literária.

Entre a frieza, o cálculo e a "vida loka": violência e sofrimento no trajeto de um adolescente em cumprimento de medida socioeducativa

O conceito de sofrimento social caracteriza-se pela compreensão das situações de aflição e dor como experiências sociais e não como problemas individuais. Este trabalho analisa a natureza social e política do sofrimento de um adolescente em cumprimento de medida socioeducativa. Inspirado na abordagem de Veena Das, o artigo se apóia em "carne" e discurso para problematizar a relação entre cidadania e segmentos juvenis discriminados, que se manifesta nas ambiguidades das práticas institucionais presentes no fluxo de execução de medidas socioeducativas. O artigo analisa as contradições entre o objetivo institucional de evitar a reincidência de atos infracionais, auxiliando o adolescente a tornar-se um cidadão autônomo, e as narrativas e expressões corporais dos adolescentes durante o cumprimento das medidas. A trajetória aqui descrita leva ao reconhecimento de que o trânsito da medida de internação para as medidas em meio aberto se dá sob a tensão entre o discurso institucional de reorganizar a vida escolar, familiar e comunitária e a experiência cotidiana dos adolescentes, que segue marcada pela constante ameaça policial e pela privação de acessos a bens públicos. O cumprimento de medidas socioeducativas acaba por reforçar entre os adolescentes a aflição de serem socialmente tidos como suspeitos e fugitivos e, consequentemente, a incorporação de um lugar social particular, o de membro do "mundo do crime". O desempenho na vida cotidiana de um "estilo bandido" revela formas de resposta ao discurso dominante no sistema socioeducativo, contexto que indica o paradoxo do Estado brasileiro, que garante uma democracia formal enquanto viola direitos civis.

Gênero, saúde materna e o paradoxo perinatal

Nos últimos 20 anos, houve uma melhoria de praticamente todos os indicadores da saúde materna no Brasil, assim como grande ampliação do acesso aos serviços de saúde. Paradoxalmente, não há qualquer evidência de melhoria na mortalidade materna. Este texto tem como objetivo trazer elementos para a compreensão deste paradoxo, através do exame dos modelos típicos de assistência ao parto, no SUS e no setor privado. Analisaremos as propostas de mudança para uma assistência mais baseada em evidências sobre a segurança destes modelos, sua relação com os direitos das mulheres, e com os conflitos de interesse e resistências à mudança dos modelos. Examinamos os pressupostos de gênero que modulam a assistência e os vieses de gênero na pesquisa neste campo, expressos na superestimação dos benefícios da tecnologia, e na subestimação ou na negação dos desconfortos e efeitos adversos das intervenções. Crenças da cultura sexual não raro são tidas como explicações 'científicas' sobre o corpo, a parturição e a sexualidade, e se refletem na imposição de sofrimentos e riscos desnecessários, nas intervenções danosas à integridade genital, e na negação do direito a acompanhantes. Esta 'pessimização do parto' é instrumental para favorecer, por comparação, o modelo da cesárea de rotina. Por fim, discutimos como o uso da categoria gênero pode contribuir para promover direitos e mudanças institucionais, como no caso dos acompanhantes no parto

THE RELEVANCE OF SUBSIDIARY INITIATIVES FOR BRAZILIAN MULTINATIONALS

The put-pose of this paper is to analyze relationship patterns between headquarters and subsidiaries of Brazilian Multinationals Enterprises (BrMNEs). The key construct for that investigation is Subsidiary Initiative, which comprises Subsidiary Entrepreneurial Orientation, Autonomy, Integration, Local Competitive Context and Business Network. A survey was carried out in a sample of 65 subsidiaries of 29 BrMNEs. The main outcome is that subsidiaries are highly integrated and receive Entrepreneurial Orientation from Headquarters (HQs), but Initiative is limited. Actually, the main determinants of subsidiary's initiatives are Local Context and Business Networking in the host country. This apparent paradox may be explained by what we call 'rebellious subsidiaries', which take initiatives based on their business environment and connections, regardless of their HQs' directions or delegation of autonomy.

Finite-size particles, advection, and chaos: A collective phenomenon of intermittent bursting

We consider finite-size particles colliding elastically, advected by a chaotic flow. The collisionless dynamics has a quasiperiodic attractor and particles are advected towards this attractor. We show in this work that the collisions have dramatic effects in the system's dynamics, giving rise to collective phenomena not found in the one-particle dynamics. In particular, the collisions induce a kind of instability, in which particles abruptly spread out from the vicinity of the attractor, reaching the neighborhood of a coexisting chaotic saddle, in an autoexcitable regime. This saddle, not present in the dynamics of a single particle, emerges due to the collective particle interaction. We argue that this phenomenon is general for advected, interacting particles in chaotic flows.

Observation of Two-Source Interference in the Photoproduction Reaction AuAu -> AuAu rho(0)

In ultraperipheral relativistic heavy-ion collisions, a photon from the electromagnetic field of one nucleus can fluctuate to a quark-antiquark pair and scatter from the other nucleus, emerging as a rho(0). The rho(0) production occurs in two well-separated (median impact parameters of 20 and 40 F for the cases considered here) nuclei, so the system forms a two-source interferometer. At low transverse momenta, the two amplitudes interfere destructively, suppressing rho(0) production. Since the rho(0) decays before the production amplitudes from the two sources can overlap, the two-pion system can only be described with an entangled nonlocal wave function, and is thus an example of the Einstein-Podolsky-Rosen paradox. We observe this suppression in 200 GeV per nucleon-pair gold-gold collisions. The interference is 87%+/- 5%(stat.)+/- 8%(syst.) of the expected level. This translates into a limit on decoherence due to wave function collapse or other factors of 23% at the 90% confidence level.

Protecting a quantum state from environmental noise by an incompatible finite-time measurement

We show that measurements of finite duration performed on an open two-state system can protect the initial state from a phase-noisy environment, provided the measured observable does not commute with the perturbing interaction. When the measured observable commutes with the environmental interaction, the finite-duration measurement accelerates the rate of decoherence induced by the phase noise. For the description of the measurement of an observable that is incompatible with the interaction between system and environment, we have found an approximate analytical expression, valid at zero temperature and weak coupling with the measuring device. We have tested the validity of the analytical predictions against an exact numerical approach, based on the superoperator-splitting method, that confirms the protection of the initial state of the system. When the coupling between the system and the measuring apparatus increases beyond the range of validity of the analytical approximation, the initial state is still protected by the finite-time measurement, according with the exact numerical calculations.

Disorders of apoptosis: Mechanisms for autoimmunity in primary immunodeficiency diseases

A number of primary immunodeficiency diseases represent a paradox of immunodeficiency and autoimmunity. In this minireview, we present basic concepts of apoptosis and disorder of apoptosis as one of the mechanisms to explain such a paradox between immunodeficiency and autoimmunity, which is exemplified by autoimmune lympho-proliferative syndrome (ALPS).

Dysregulation of renal transient receptor potential melastatin 6/7 but not paracellin-1 in aldosterone-induced hypertension and kidney damage in a model of hereditary hypomagnesemia

Rationale Hyperaldosteronism, important in hypertension, is associated with electrolyte alterations, including hypomagnesemia, through unknown mechanisms. Objective To test whether aldosterone influences renal Mg(2+) transporters, (transient receptor potential melastatin (TRPM) 6, TRPM7, paracellin-1) leading to hypomagnesemia, hypertension and target organ damage and whether in a background of magnesium deficiency, this is exaggerated. Methods and results Aldosterone effects in mice selectively bred for high-normal (MgH) or low (MgL) intracellular Mg(2+) were studied. Male MgH and MgL mice received aldosterone (350 mu g/kg per day, 3 weeks). SBP was elevated in MgL. Aldosterone increased blood pressure and albuminuria and increased urinary Mg(2+) concentration in MgH and MgL, with greater effects in MgL. Activity of renal TRPM6 and TRPM7 was lower in vehicle-treated MgL than MgH. Aldosterone increased activity of TRPM6 in MgH and inhibited activity in MgL. TRPM7 and paracellin-1 were unaffected by aldosterone. Aldosterone-induced albuminuria in MgL was associated with increased renal fibrosis, increased oxidative stress, activation of mitogen-activated protein kinases and nuclear factor-NF-kappa B and podocyte injury. Mg(2+) supplementation (0.75% Mg(2+)) in aldosterone-treated MgL normalized plasma Mg(2+), increased TRPM6 activity and ameliorated hypertension and renal injury. Hence, in a model of inherited hypomagnesemia, TRPM6 and TRPM7, but not paracellin-1, are downregulated. Aldosterone further decreased TRPM6 activity in hypomagnesemic mice, a phenomenon associated with hypertension and kidney damage. Such effects were prevented by Mg(2+) supplementation. Conclusion Amplified target organ damage in aldosterone-induced hypertension in hypomagnesemic conditions is associated with dysfunctional Mg(2+)-sensitive renal TRPM6 channels. Novel mechanisms for renal effects of aldosterone and insights into putative beneficial actions of Mg(2+), particularly in hyperaldosteronism, are identified. J Hypertens 29: 1400-1410 (C) 2011 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.

Climate perspective on the large-scale circulation associated with the transition of the first South Atlantic hurricane

The landfall of Cyclone Catarina on the Brazilian coast in March 2004 became known as the first documented hurricane in the South Atlantic Ocean, promoting a new view oil how large-scale features can contribute to tropical transition. The aim of this paper is to put the large-scale circulation associated with Catarina`s transition in climate perspective. This is discussed in the light of a robust pattern of spatial correlations between thermodynamic and dynamic variables of importance for hurricane formation. A discussion on how transition mechanisms respond to the present-day circulation is presented. These associations help in understanding why Catarina was formed in a region previously thought to be hurricane-free. Catarina developed over a large-scale area of thermodynamically favourable air/sea temperature contrast. This aspect explains the paradox that such a rare system developed when the sea surface temperature was slightly below average. But, although thermodynamics played an important role, it is apparent that Catarina would not have formed without the key dynamic interplay triggered by a high latitude blocking. The blocking was associated with an extreme positive phase of the Southern Annular Mode (SAM) both hemispherically and locally, and the nearby area where Catarina developed is found to be more cyclonic during the positive phase of the SAM. A conceptual model is developed and a `South Atlantic index` is introduced as a useful diagnostic of potential conditions leading to tropical transition in the area, where large-scale indices indicate trends towards more favourable atmospheric conditions for tropical cyclone formation. Copyright (c) 2008 Royal Meteorological Society

Autoimmunity in common variable immunodeficiency

immunodeficiency (CVID), the most common symptomatic primary immunodeficiency in adulthood. Different authors report high prevalences of autoimmune diseases in CVID, and several mechanisms have been proposed to explain this apparent paradox. Genetic predisposition, under current surveillance, innate and adaptive immunity deficiencies leading to persistent/recurrent infections, variable degrees of immune dysregulation, and possible failure in central and peripheral mechanisms of tolerance induction or maintenance may all contribute to increased autoimmunity. Conclusions Data on the clinical/immunological profile of affected patients and treatment are available mostly concerning autoimmune cytopenias, the most common autoimmune diseases in CVID. Treatment is based on conventional alternatives, in association with short experience with new agents, including rituximab and infliximab. Benefits of early immunoglobulin substitutive treatment and hypothetical premature predictors of autoimmunity are discussed as potential improvements to CVID patients` follow-up.