100 research outputs found

    Spatial period-multiplying instabilities of hexagonal Faraday waves

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    A recent Faraday wave experiment with two-frequency forcing reports two types of `superlattice' patterns that display periodic spatial structures having two separate scales. These patterns both arise as secondary states once the primary hexagonal pattern becomes unstable. In one of these patterns (so-called `superlattice-II') the original hexagonal symmetry is broken in a subharmonic instability to form a striped pattern with a spatial scale increased by a factor of 2sqrt{3} from the original scale of the hexagons. In contrast, the time-averaged pattern is periodic on a hexagonal lattice with an intermediate spatial scale (sqrt{3} larger than the original scale) and apparently has 60 degree rotation symmetry. We present a symmetry-based approach to the analysis of this bifurcation. Taking as our starting point only the observed instantaneous symmetry of the superlattice-II pattern presented in and the subharmonic nature of the secondary instability, we show (a) that the superlattice-II pattern can bifurcate stably from standing hexagons; (b) that the pattern has a spatio-temporal symmetry not reported in [1]; and (c) that this spatio-temporal symmetry accounts for the intermediate spatial scale and hexagonal periodicity of the time-averaged pattern, but not for the apparent 60 degree rotation symmetry. The approach is based on general techniques that are readily applied to other secondary instabilities of symmetric patterns, and does not rely on the primary pattern having small amplitude

    STAT1 activation in association with JAK2 exon 12 mutations

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    La inclusión de la perspectiva de género en la actividad jurisdiccional es una demanda sostenida de los colectivos feministas y de mujeres, dado que las sentencias tienen un poder performativo y envían un mensaje a la sociedad: “[…] tienen un poder individual y colectivo que impactan en la vida de las personas y conforman la identidad del poder judicial como un actor imprescindible en la construcción de un Estado democrático de derecho” (Suprema Corte de Justicia de la Nación, 2013:7). La incorporación de la perspectiva de género viene a garantizar la igualdad de posiciones (Kessler, 2014) entre mujeres y varones como una meta, trascendiendo la mera igualdad de oportunidades que hasta el presente se ha demostrado insuficiente para que las mujeres consigamos una ciudadanía plena. Al momento de incorporar la perspectiva de género en las sentencias, quienes juzgan deben tener presente en primer lugar, el impacto diferenciado de las normas en base al sexo de las personas. En segundo lugar, la interpretación y aplicación de las leyes en relación con (y en base a) estereotipos de género. Si, por ejemplo, quienes imparten justicia no tienen presentes los estereotipos de género vigentes detrás de las violaciones a los derechos humanos de las mujeres, si no los detectan ni cuestionan, entonces los reproducen. Tal como sostiene Scott (1996) el género es una categoría imprescindible para el análisis social. En tercer lugar, al momento del juzgamiento, se deben tener en cuenta las exclusiones legitimadas por la ley por pensar el mundo en términos binarios y androcéntricos; en cuarto lugar, la distribución no equitativa de recursos y poder que opera entre varones y mujeres en el marco de una organización social patriarcal, y, por último, el trato diferenciado por género legitimado por las propias leyes.Eje 3: Tramas violentas y espacios de exclusión.Instituto de Cultura Jurídic

    Role of ¿1-pyrroline-5-carboxylate dehydrogenase supports mitochondrial metabolism and host-cell invasion of Trypanosoma cruzi

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    Proline is crucial for energizing critical events throughout the life cycle of Trypanosoma cruzi, the etiological agent of Chagas disease. The proline breakdown pathway consists of two oxidation steps, both of which produce reducing equivalents as follows: the conversion of proline to ¿1-pyrroline-5-carboxylate (P5C), and the subsequent conversion of P5C to glutamate. We have identified and characterized the ¿1-pyrroline-5-carboxy- late dehydrogenase from T. cruzi (TcP5CDH) and report here on how this enzyme contributes to a central metabolic pathway in this parasite. Size-exclusion chromatography, two-dimen- sional gel electrophoresis, and small angle x-ray scattering analysis of TcP5CDH revealed an oligomeric state composed of two subunits of six protomers. TcP5CDH was found to complement a yeast strain deficient in PUT2 activity, confirming the enzyme’s functional role; and the biochemical parameters (Km, kcat, and kcat/Km) of the recombinant TcP5CDH were determined, exhibiting values comparable with those from T. cruzi lysates. In addition, TcP5CDH exhibited mitochondrial staining during the main stages of the T. cruzi life cycle. mRNA and enzymatic activity levels indicated the up-regulation (6-fold change) of TcP5CDH during the infective stages of the parasite. The participation of P5C as an energy source was also demonstrated. Overall, we propose that this enzymatic step is crucial for the viability of both replicative and infective forms of T. cruzi

    End-tidal carbon dioxide monitoring during bag valve ventilation: the use of a new portable device

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    <p>Abstract</p> <p>Background</p> <p>For healthcare providers in the prehospital setting, bag-valve mask (BVM) ventilation could be as efficacious and safe as endotracheal intubation. To facilitate the evaluation of efficacious ventilation, capnographs have been further developed into small and convenient devices able to provide end- tidal carbon dioxide (ETCO<sub>2</sub>). The aim of this study was to investigate whether a new portable device (EMMA™) attached to a ventilation mask would provide ETCO<sub>2 </sub>values accurate enough to confirm proper BVM ventilation.</p> <p>Methods</p> <p>A prospective observational trial was conducted in a single level-2 centre. Twenty-two patients under general anaesthesia were manually ventilated. ETCO<sub>2 </sub>was measured every five minutes with the study device and venous PCO<sub>2 </sub>(PvCO<sub>2</sub>) was simultaneously measured for comparison. Bland- Altman plots were used to compare ETCO<sub>2, </sub>and PvCO<sub>2</sub>.</p> <p>Results</p> <p>The patients were all hemodynamically and respiratory stable during anaesthesia. End-tidal carbon dioxide values were corresponding to venous gases during BVM ventilation under optimal conditions. The bias, the mean of the differences between the two methods (device versus venous blood gases), for time points 1-4 ranges from -1.37 to -1.62.</p> <p>Conclusion</p> <p>The portable device, EMMA™ is suitable for determining carbon dioxide in expired air (kPa) as compared to simultaneous samples of PvCO<sub>2</sub>. It could therefore, be a supportive tool to asses the BVM ventilation in the demanding prehospital and emergency setting.</p

    Prognostic implications of coronary calcification in patients with obstructive coronary artery disease treated by percutaneous coronary intervention: A patient-level pooled analysis of 7 contemporary stent trials

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    Objective To investigate the long- Term prognostic implications of coronary calcification in patients undergoing percutaneous coronary intervention for obstructive coronary artery disease. Methods Patient-level data from 6296 patients enrolled in seven clinical drug-eluting stents trials were analysed to identify in angiographic images the presence of severe coronary calcification by an independent academic research organisation (Cardialysis, Rotterdam, The Netherlands). Clinical outcomes at 3-years follow-up including all-cause mortality, death-myocardial infarction (MI), and the composite end-point of all-cause death-MI- Any revascularisation were compared between patients with and without severe calcification. Results Severe calcification was detected in 20% of the studied population. Patients with severe lesion calcification were less likely to have undergone complete revascularisation (48% vs 55.6%, p<0.001) and had an increased mortality compared with those without severely calcified arteries (10.8% vs 4.4%, p<0.001). The event rate was also high in patients with severely calcified lesions for the combined end-point death-MI (22.9% vs 10.9%; p<0.001) and death-MI- Any revascularisation (31.8% vs 22.4%; p<0.001). On multivariate Cox regression analysis, including the Syntax score, the presence of severe coronary calcification was an independent predictor of poor prognosis (HR: 1.33 95% CI 1.00 to 1.77, p=0.047 for death; 1.23, 95% CI 1.02 to 1.49, p=0.031 for death-MI, and 1.18, 95% CI 1.01 to 1.39, p=0.042 for death-MI- Any revascularisation), but it was not associated with an increased risk of stent thrombosis. Conclusions Patients with severely calcified lesions have worse clinical outcomes compared to those without severe coronary calcification. Severe coronary calcification appears as an independent predictor of worse prognosis, and should be considered as a marker of advanced atherosclerosis

    EFFECT OF CORTISOL TREATMENT ON HORMONAL RELATIONSHIPS IN CONGENITAL ADRENAL HYPERPLASIA

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    The temporal relationship between administration of cortisol and serum 17Α-hydroxyprogesterone was investigated in five patients aged 9-19 years with congenital adrenal hyperplasia due to 21-hydroxylase deficiency. There was marked variability in the 17Α-hydroxyprogesterone response (determined hourly for 24 h) of individual patients to administration of cortisol. Mean concentration was less than 0.030 Μmol/l in one patient but 0.519Μ mol/l in another. Levels were higher in all patients while off treatment, and were greatest in those with salt-losing adrenal hyperplasia. Growth hormone secretion was not suppressed by treatment with cortisol. Withdrawal of cortisol for 3 days resulted in a significant decrease in the mean serum FSH/LH ratio and a rise in serum testosterone in all subjects. Episodic release of gonadotrophins persisted in the adolescent patients.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75713/1/j.1365-2265.1977.tb02002.x.pd

    Toward a 21st-century health care system: Recommendations for health care reform

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    The coverage, cost, and quality problems of the U.S. health care system are evident. Sustainable health care reform must go beyond financing expanded access to care to substantially changing the organization and delivery of care. The FRESH-Thinking Project (www.fresh-thinking.org) held a series of workshops during which physicians, health policy experts, health insurance executives, business leaders, hospital administrators, economists, and others who represent diverse perspectives came together. This group agreed that the following 8 recommendations are fundamental to successful reform: 1. Replace the current fee-for-service payment system with a payment system that encourages and rewards innovation in the efficient delivery of quality care. The new payment system should invest in the development of outcome measures to guide payment. 2. Establish a securely funded, independent agency to sponsor and evaluate research on the comparative effectiveness of drugs, devices, and other medical interventions. 3. Simplify and rationalize federal and state laws and regulations to facilitate organizational innovation, support care coordination, and streamline financial and administrative functions. 4. Develop a health information technology infrastructure with national standards of interoperability to promote data exchange. 5. Create a national health database with the participation of all payers, delivery systems, and others who own health care data. Agree on methods to make de-identified information from this database on clinical interventions, patient outcomes, and costs available to researchers. 6. Identify revenue sources, including a cap on the tax exclusion of employer-based health insurance, to subsidize health care coverage with the goal of insuring all Americans. 7. Create state or regional insurance exchanges to pool risk, so that Americans without access to employer-based or other group insurance could obtain a standard benefits package through these exchanges. Employers should also be allowed to participate in these exchanges for their employees' coverage. 8. Create a health coverage board with broad stakeholder representation to determine and periodically update the affordable standard benefit package available through state or regional insurance exchanges
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