Ab initio study of the elastic behavior of MgSiO3 ilmenite at high pressure

We investigate the athermal high pressure behavior of the elastic properties of MgSiO3 ilmenite up to 30 GPa using the ab initio pseudopotential method. Our results at zero pressure are in good agreement with single-crystal elasticity measurements. The elastic anisotropy is shown to decrease slightly under compression and hence to remain substantial (25 to 20% shear wave anisotropy and 16 to 10% longitudinal wave anisotropy) over the pressure regime studied. The directions of fastest and slowest wave propagation are found to change slightly with pressure as determined by the pressure dependence of c(14) and c(25). Comparisons with the elastic behavior of other deep transition zone phases such as ringwoodite and garnet show that ilmenite is likely to be the fastest and most anisotropic mineral in this region. Large contrasts (approximate to 10%) in velocities and densities between ilmenite and garnet are suggested to be significant for the interpretation of lateral structure in the transition zone

Law as Counterspeech

A growing body of work in free speech theory is interested in the nature of counterspeech, i.e. speech that aims to counteract the effects of harmful speech. Counterspeech is usually defined in opposition to legal responses to harmful speech, which try to prevent such speech from occurring in the first place. In this paper we challenge this way of carving up the conceptual terrain. Instead, we argue that our main classificatory division, in theorising responses to harmful speech, should be between pro-discursive and anti-discursive responses. Some legal responses to harmful speech, so we argue, make a positive discursive contribution in their own right. That is, legal restrictions on harmful speech can have a function that is importantly similar to speech that aims at countering the effects of harmful speech

Quantification of respiratory parameters in patients with temporal lobe epilepsy

Dysfunction affecting cardiac or pulmonary systems has been postulated as a major factor in sudden death in epilepsy (SUDEP). Whilst the majority of studies of cardiorespiratory function have focused on changes during seizures, here we investigate whether epilepsy influences basal respiratory parameters in patients with temporal lobe epilepsy (TLE) during the interictal period. Spirometry was performed in 10 females and 10 males. Measurements of Vital Capacity (VC), Forced Vital Capacity (FVC), Forced Expiratory Volume in the first second (FEV1) and ratios of FEV1 to FVC (FEV1/FVC) were obtained, and these values were analyzed as percentages of predicted values. None of the patients had chronic obstructive pulmonary disease and no significant alterations in respiratory function tests were found among these patients. No association between seizure frequency, antiepileptic drugs and SUDEP could be found in this study. Although the study did not identify any specific respiratory abnormality in TLE patients during the interictal period, re-evaluation of clinical data on pulmonary disorders in people with epilepsy should be better investigated

Partial Transphyseal Technique for Anterior Cruciate Ligament Reconstruction in Skeletally Immature Patients

With more and more children participating in competitive sports at younger and younger ages, we have seen an increase in the incidence and diagnosis of intrasubstance ruptures of the anterior cruciate ligament. As in adults, the instability of the ligaments predisposes children to a potential risk of meniscos and chondral injuries with consequent early degenerative alterations. The timely treatment of these injuries is crucial and the surgical technique depends directly on the patient’s physiological age. The authors present a clinical case of the complete rupture of the anterior cruciate ligament in a skeletally immature child, surgically treated by a partial transphyseal technique, with an excellent functional result

Polyvalent horse F(Ab`)2 snake antivenom: Development of process to produce polyvalent horse F(Ab`)2 antibodies anti-african snake venom

A method to obtain polyvalent anti-Bitis and polyvalent-anti-Naja antibodies was developed by immunizing horses with B. arietans, B. nasicornis, B. rhinoceros, N. melanoleuca and N. mossambicacrude venoms. Antibody production was followed by the ELISA method during the immunization procedure. Once the desired anti-venom antibody titers were attained, horses were bled and the immunoglobulins were separated from the sera by (NH4)2SO4 precipitation, cleaved with pepsin and filtered through a 30 kDa ultrafiltration membrane. F(ab´)2 fragments were further purified by Q-Fast Flow chromatography, concentrated by molecular ultrafiltration and sterilized by filtration through 0.22 m membranes. The resulting F(ab´)2 preparations were rich in intact L and in pieces of H IgG(T) chains, as demonstrated by electrophoresis and Western blot and exhibited high antibody titers, as assayed by the ELISA method. In addition, the preparations possess a significant capacity to neutralize the lethality of venoms, as estimated by ED50 determination in mouse assay and are free of toxic substances, pyrogen and bacterial or fungal contaminations

Elastic constants and anisotropy of forsterite at high pressure

We have determined from first principles the athermal elastic constant tensor of Mg2SiO4 forsterite with the plane wave pseudopotential method over a wide range of pressure (0-100 GPa) that encompasses the full range over which forsterite has been observed experimentally. The computed elastic constants are in excellent agreement with experimental data up to the maximum pressure of the experiments (16 GPa). We calculate the single-crystal elastic anisotropy from the elastic constants. We find that the anisotropy is strong (azimuthal P- and S-wave anisotropy: 25 % and 20 %, respectively, polarization anisotropy: 15 %), in agreement with experiment, and that it depends weakly on pressure over the range 0-25 GPa, in contrast to the behavior of other silicates and oxides

Rupture of a Congenital Aneurysm of the Non-Coronary Sinus of Valsalva Into the Right Atrium

Apresenta-se o caso de um doente avaliado por sopro cardíaco contínuo, em que o estudo ecocardiográfico permitiu diagnosticar ruptura de aneurisma congénito do seio de Valsalva (SV) para a aurícula direita. Os autores fazem uma breve revisão sobre os aspectos clínicos desta patologia

Echocardiographic Variables Predictive of Appropriate Therapies for Ventricular Tachyarrhythmia in Patients Undergoing Combined Cardiac Resynchronization Therapy

INTRODUCTION: The significant risk of sudden arrhythmic death in patients with congestive heart failure and electromechanical ventricular dyssynchrony has led to increased use of combined cardiac resynchronization therapy defibrillator (CRT-D) devices. OBJECTIVES: To evaluate the echocardiographic variables in patients undergoing CRT-D that predict the occurrence of appropriate therapies (AT) for ventricular tachyarrhythmia. METHODS: We analyzed 38 consecutive patients (mean age 60 +/- 12 years, 63% male) with echocardiographic evaluation before and 6 months after CRT-D implantation. Patients with AT were identified in a mean follow-up of 471 +/- 323 days. A standard echocardiographic study was performed including tissue Doppler imaging (TDI). Responders were defined as patients with improvement in NYHA class of 25%. RESULTS: The responder rate was 74%, and the reverse remodeling rate was 55%. AT occurred in 21% of patients, who presented with greater left ventricular end-diastolic internal diameter (LVEDD) before implantation (86 +/- 8 vs. 76 +/- 11 mm, p = 0.03) and at 6 months (81 +/- 8 vs. 72 +/- 14 mm, p = 0.08), and increased left ventricular end-systolic internal diameter (66 +/- 14 vs. 56 +/- 14 mm, p = 0.03) and lower ejection fraction (24 +/- 6 vs. 34 +/- 14%, p = 0.08) at 6 months. In the group with AT, the responder rate was lower (38 vs. 83%, p = 0.03), without significant differences in reverse remodeling (38% for the AT group vs. 60%, p = 0.426) or in the other variables. By univariate analysis, predictors of AT were LVEDD before implantation and E' after implantation. Age, gender, ischemic etiology, use of antiarrhythmic drugs, reverse remodeling and the other echocardiographic parameters did not predict AT. In multivariate logistic regression analysis, both LVEDD before implantation (OR 1.24, 95% CI 1.04-1.48, p = 0.019) and postimplantation E' (OR 0.27, 95% CI 0.09-0.76, p = 0.014) remained as independent predictors of AT. CONCLUSIONS: In patients undergoing CRT-D, episodes of ventricular tachyarrhythmia occur with high incidence, independently of echocardiographic response, with LVEDD before implantation and E' after implantation as the only independent predictors of AT in the medium-term. These results highlight the importance of combined devices with defibrillation capability