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SUMMARY Background Human platelet antigens (HPAs) are alloantigens derived from polymorphisms in platelet-surface glycoproteins. The occurrence of alloantibodies against HPAs can lead to platelet destruction and subsequent thrombocytopenia. Brazilians have a high rate of racial admixture, and the knowledge of HPA polymorphisms in particular donors from north Brazil, who have a large Amerindian influence, is a relevant strategy to prevent alloimmunisation. Objective Our aim was investigate the HPA allele's frequencies in the Amazonas blood donors. Methods We performed HPA genotyping among 200 Amazonas blood donors by microarray for 11 HPA biallelic systems, including six of the most clinically significant systems (HPA-1 to -5 and -15) and five others (HPA-6 to -9 and -11) that have been also associated with alloimmunisation, amounting to 22 HPA alleles. Results The obtained allele frequencies were compared with data of 38 populations worldwide to determine the hierarchical relationship and estimated the probability of mismatch platelets. The allele frequencies were 0·862 for HPA-1 a, 0·137 for HPA-1 b, 0·852 for HPA-2 a, 0·147 for HPA-2 b, 0·665 for HPA-3 a, 0·335 for HPA-3 b, 0·995 for HPA-4 a, 0·005 for HPA-4 b, 0·892 for HPA-5 a, 0·107 for HPA-5 b, 0·997 for HPA-9 a, 0·005 for HPA-9 b, 0·502 for HPA-15 a and 0·497 for HPA-15 b. The incompatibility risks are higher for HPA-15 and HPA-3, followed by HPA-1, -2 and -5. Conclusion We found differences among populations worldwide, and it is interesting to note the indigenous and European influences in this region, reinforcing the heterogeneity in the ancestry of Brazilians. The results will be helpful in providing information for platelet transfusion to avoid alloimmunisation. [ABSTRACT FROM AUTHOR]

Several studies have reported that peak oxygen consumption (pVO2) is diminished after continuous flow (CF) LVAD support and recent data shows that pVO2 post LVAD predicts outcomes. It has been suggested that augmentation of native cardiac output (NCO) and not LVAD flow supports exercise. Using simultaneous metabolic and hemodynamic measures, we further studied the determinants of maximal exercise with the Heartmate 3 (HM3) LVAD. Subjects underwent maximal upright bicycle exercise testing utilizing a 10-15 W ramp protocol with hemodynamic measurements from a right heart and radial arterial catheter, and CPET testing with a metabolic cart (Metalyzer 3B, Cortex, Germany). Mid-point hemodynamics were acquired to plot pressure/flow relationships. NCO was calculated by subtracting LVAD flow from Fick cardiac output (FCO). Arterial lactate and regional tissue oxygenation (rSO2) with the NIRS SenSmart™ were also measured. Six HM3 subjects (43-76 yrs) were studied at least 12 weeks post implant, all were on at least 2 neurohormonal agents. All patients performed maximal exercise (RER 1.10-1.34). Most did not demonstrate chronotropic incompetence; achieving median 80.8 (63.5- 90.9) % of predicted heart rate. We saw robust oxygen extraction, with median peak A-VO2 difference 14.2 (10.5-15.8) mL/100mL with no change in rSO2 and median peak lactate 6.5 (3.5-9.9) mmol/L. However, 5/6 subjects achieved pVO2 ≤14 ml/kg/min. During exercise, there was minimal augmentation of LVAD flow (0.4-1.6 L/min) while NCO increased by 2.0-7.1 L/min. Mean pulmonary artery (mPA)/FCO relationships were available for 5 subjects (Fig.1), demonstrating abnormal rate of rise of mPA in all patients (slope 3.7-7.0, normal < 3). Neither chronotropic response nor peripheral extraction appeared to limit exercise. Steep rise in mPA suggests either impaired pulmonary vasoreactivity and or cardiac reserve may be the key determinants of exercise capacity during HM3 support. Further study will clarify these factors. [ABSTRACT FROM AUTHOR]

A paper representation of soil behaviour for transient studies is presented. Such representation is more accurate than the most common procedures of engineering practice and, in several conditions, lead to results with important differences. The proposed model takes into account the earth's conductivity and permittivity frequency dependence, which normally are not considered. One of the aspects covered in the paper is the importance of properly considering the earth's electromagnetic behaviour when calculating transmission line parameters. Some comparisons are presented for an actual 440kV three-phase transmission line in which the soil behaviour is represented through a unique real value of conductance (the normal approach) and through the proposed model. [ABSTRACT FROM AUTHOR]

We have carried out a statistical analysis of the kinematical behavior of small white-light transients (blobs) as tracers of the slow solar wind. The characterization of these faint white-light structures gives us insight on the origin and acceleration of the slow solar wind. The vantage observing points provided by the SECCHI and LASCO instruments on board the STEREO and SOHO spacecraft, respectively, allow us to reconstruct the 3D trajectories of these blob-like features and hence calculate their deprojected kinematical parameters. We have studied 44 blobs revealed in LASCO C2/C3 and SECCHI COR2 data from 2007 to 2008, a period within the solar minimum between Solar Cycles 23 and 24. We found that the blobs propagate along approximately constant position angles with accelerations from 1.40 to 15.34ms−2 between 3.42 R☉ and 14.80 R☉, their radial sizes ranging between 0.57 R☉ and 1.69 R☉. We also studied the global corona magnetic field morphology for a subset of blobs using a potential field source surface model for cases where blob detachments persist for two to five days. The study of localized blob releases indicates that these plasma structures start their transit at a distance of ∼3.40R☉ and their origin is connected either with the boundaries of weak coronal holes or with streamers at equatorial latitudes. [ABSTRACT FROM AUTHOR]

The Rubia Gallega cattle breed is the most important stock for beef production in Spain. A study about the influence of feeding systems on beef quality is needed. Comparison of the effect of a pasture finishing system and an indoors finishing system (maize silage and concentrate) on the meat quality and intramuscular fatty acid profile of Rubia Gallega steers (slaughter age 30 months) was determined using samples of Longissimus thoracis muscle. There were no differences between treatments in meat pH, drip loss, water holding capacity, cooking loss and muscle colour. Meat from pasture-fed steers was more tender than meat from indoors finished ones at 24 h post-mortem, but differences disappeared at 7 days. Subcutaneous fat of grass-fed steers showed higher yellowness at 24 h and 7 days post-mortem and lower brightness at 7 days post-mortem than indoors finished ones. Intramuscular fat of indoors finished steers presented higher concentrations of C18:2 and a less favourable ratio of n−6/n−3 polyunsaturated fatty acids than pasture finished steers. [Copyright &y& Elsevier]