Factor VII and the brain: time to get this research done!

Traumatic brain injury is the leading killer after trauma, in part because of coagulopathy. Factor VIIa may be a useful therapy in this setting, depending on the relative risk for thromboembolic complications. Kluger and coworkers recently conducted a retrospective review of patients with traumatic brain injury from a previous factor VIIa and trauma trial. It documents an encouragingly low rate of complications, and should provide a strong incentive to conduct a prospective study of factor VIIa in patients with severe traumatic brain injury

Geologic and Hydrologic Controls on Reservoir-Scale Variability in Formation-Water Compositions

Subsurface formation waters exhibit regional trends in measured chemistries, but the data also exhibit marked local variance that has not been adequately described or explained. An integrated study of chemical, petrologic, and fluid-pressure data from a well-characterized natural gas field in the Gulf Coast basin will allow us to determine reservoir-scale controls on chemical and diagenetic variability. Understanding the controls on chemistry can provide insight into fluid flow and rock-water interactions in similar geologic settings. Knowledge of solute distributions will aid in the assessment of compartmentalization within reservoirs and fluid communication between reservoirs. Such assessment is relevant not only to improved hydrocarbon exploitation but also to the safe injection of chemical wastes. Finally, understanding small-scale chemical changes would further the interpretation of regional variations in water chemistry, diagenetic facies, and fluid flow within the Cenozoic section of the Gulf Coast basin. This interpretation is potentially important in the study of hydrocarbon migration and entrapment. We propose to sample in detail formation waters from Stratton Field in Nueces and Kleberg Counties, Texas, in order to map and interpret chemical variations within and between individual reservoirs. The results of water analyses will be mapped with respect to facies and reservoir geometries and features such as faults in order to determine stratigraphic, structural, and hydraulic controls on chemical variability. Hydrochemical data will be compared with mineralogic analyses of core, and geochemical modeling will be conducted. Results will be assessed in terms of the extent of rock-water equilibration to determine plausible reaction and mixing sequences along flow paths.Bureau of Economic Geolog

Blood transfusion in critical care

Blood transfusion is frequent in critical care. Transfusion raises the mass of transfused blood components and is lifesaving in acute hemorrhage. In massive transfusion (>10 units of red blood cells), early attempts to restore coagulation function appear helpful. Transfusion in non-bleeding patients is largely prophylactic, is seldom evidence-based, and may be deleterious. In hemodynamically stable critical care patients, level I evidence suggests that a hemoglobin of >7 g/dL and platelet counts of >10,000/μL are well tolerated

Types and correlates of school non-attendance in students with autism spectrum disorders

School non-attendance in autism spectrum disorders (ASD) has received very little attention to date. The study aimed to provide a comprehensive description of school non-attendance in students with ASD. Through an online survey, parents of 486 children (mean age 11 years) reported on school attendance over one month, and reasons for instances of non-attendance. On average, students missed five days of school of a possible 23 days. Persistent non-attendance (absent on 10%+ of available sessions) occurred among 43% of students. School non-attendance was associated with child older age, not living in a two-parent household, parental unemployment and, especially, attending a mainstream school. School refusal accounted for 43% of non-attendance. School exclusion and school withdrawal each accounted for 9% of absences. Truancy was almost non-existent. Non-problematic absenteeism (mostly related to medical appointments and illness) accounted for 32% of absences. Non-problematic absenteeism was more likely among those with intellectual disability, school refusal was more likely among older students, and school exclusion was more likely among students from single-parent, unemployed, and well educated households. Findings suggest school non-attendance in ASD is a significant issue, and that it is important to capture detail about attendance patterns and reasons for school non-attendance

A retrospective analysis of clinical use of alirocumab in lipoprotein apheresis patients

BACKGROUND: The previously published ODYSSEY ESCAPE trial demonstrated a significant reduction in the use of lipoprotein apheresis for heterozygous familial hypercholesterolemia (HeFH) patients when placed on alirocumab 150 mg every 2 weeks. In patients with HeFH who have consistently elevated levels of low-density lipoprotein cholesterol (LDL-C) despite maximally tolerated statin therapy, current lipid guidelines recommend apheresis. Although apheresis reduces LDL-C levels by 50%-75%, it must be repeated, as frequently as every 1-2 weeks. OBJECTIVE: To assess clinical experience with apheresis and alirocumab for patients in a real-world practice setting. METHODS: This retrospective review included patients from 5 apheresis centers who were treated with apheresis and had started alirocumab therapy. In addition to LDL-C levels, total cholesterol, high-density lipoprotein cholesterol (HDL-C), non-HDL-C, triglycerides, and particle numbers were evaluated if data were available. RESULTS: Eleven of the 25 (44%) patients discontinued apheresis completely after initiation of alirocumab therapy, having achieved LDL-C \u3c70 mg/dL or \u3e50% reduction from baseline levels. Among the 14 patients who remained on apheresis, seven decreased the frequency of apheresis sessions. No significant safety problems were reported. CONCLUSION: Alirocumab lowered LDL-C levels by an average of 55.5% in patients receiving apheresis for elevated LDL-C. Seventy-two percent of patients on alirocumab therapy discontinued or reduced the frequency of apheresis treatment. However, some patients continued to require apheresis due to elevated lipoprotein(a), extremely elevated LDL-C, or if alirocumab therapy was discontinued due to less than anticipated LDL-C reduction

Formalising the Continuous/Discrete Modeling Step

Formally capturing the transition from a continuous model to a discrete model is investigated using model based refinement techniques. A very simple model for stopping (eg. of a train) is developed in both the continuous and discrete domains. The difference between the two is quantified using generic results from ODE theory, and these estimates can be compared with the exact solutions. Such results do not fit well into a conventional model based refinement framework; however they can be accommodated into a model based retrenchment. The retrenchment is described, and the way it can interface to refinement development on both the continuous and discrete sides is outlined. The approach is compared to what can be achieved using hybrid systems techniques.Comment: In Proceedings Refine 2011, arXiv:1106.348

Multiple Distant Origins for Green Sea Turtles Aggregating off Gorgona Island in the Colombian Eastern Pacific

Mitochondrial DNA analyses have been useful for resolving maternal lineages and migratory behavior to foraging grounds (FG) in sea turtles. However, little is known about source rookeries and haplotype composition of foraging green turtle aggregations in the southeastern Pacific. We used mitochondrial DNA control region sequences to identify the haplotype composition of 55 green turtles, Chelonia mydas, captured in foraging grounds of Gorgona National Park in the Colombian Pacific. Amplified fragments of the control region (457 bp) revealed the presence of seven haplotypes, with haplotype (h) and nucleotide (π) diversities of h = 0.300±0.080 and π = 0.009±0.005 respectively. The most common haplotype was CMP4 observed in 83% of individuals, followed by CMP22 (5%). The genetic composition of the Gorgona foraging population primarily comprised haplotypes that have been found at eastern Pacific rookeries including Mexico and the Galapagos, as well as haplotypes of unknown stock origin that likely originated from more distant western Pacific rookeries. Mixed stock analysis suggests that the Gorgona FG population is comprised mostly of animals from the Galapagos rookery (80%). Lagrangian drifter data showed that movement of turtles along the eastern Pacific coast and eastward from distant western and central Pacific sites was possible through passive drift. Our results highlight the importance of this protected area for conservation management of green turtles recruited from distant sites along the eastern Pacific Ocean

A systematic variation of the stellar initial mass function in early-type galaxies

Much of our knowledge of galaxies comes from analysing the radiation emitted by their stars. It depends on the stellar initial mass function (IMF) describing the distribution of stellar masses when the population formed. Consequently knowledge of the IMF is critical to virtually every aspect of galaxy evolution. More than half a century after the first IMF determination, no consensus has emerged on whether it is universal in different galaxies. Previous studies indicated that the IMF and the dark matter fraction in galaxy centres cannot be both universal, but they could not break the degeneracy between the two effects. Only recently indications were found that massive elliptical galaxies may not have the same IMF as our Milky Way. Here we report unambiguous evidence for a strong systematic variation of the IMF in early-type galaxies as a function of their stellar mass-to-light ratio, producing differences up to a factor of three in mass. This was inferred from detailed dynamical models of the two-dimensional stellar kinematics for the large Atlas3D representative sample of nearby early-type galaxies spanning two orders of magnitude in stellar mass. Our finding indicates that the IMF depends intimately on a galaxy's formation history.Comment: 4 pages, 2 figures, LaTeX. Accepted for publication as a Nature Letter. More information about our Atlas3D project is available at http://purl.org/atlas3