Crossing barriers in planetesimal formation: The growth of mm-dust aggregates with large constituent grains

Collisions of mm-size dust aggregates play a crucial role in the early phases of planet formation. We developed a laboratory setup to observe collisions of dust aggregates levitating at mbar pressures and elevated temperatures of 800 K. We report on collisions between basalt dust aggregates of from 0.3 to 5 mm in size at velocities between 0.1 and 15 cm/s. Individual grains are smaller than 25 \mum in size. We find that for all impact energies in the studied range sticking occurs at a probability of 32.1 \pm 2.5% on average. In general, the sticking probability decreases with increasing impact parameter. The sticking probability increases with energy density (impact energy per contact area). We also observe collisions of aggregates that were formed by a previous sticking of two larger aggregates. Partners of these aggregates can be detached by a second collision with a probability of on average 19.8 \pm 4.0%. The measured accretion efficiencies are remarkably high compared to other experimental results. We attribute this to the rel. large dust grains used in our experiments, which make aggregates more susceptible to restructuring and energy dissipation. Collisional hardening by compaction might not occur as the aggregates are already very compact with only 54 \pm 1% porosity. The disassembly of previously grown aggregates in collisions might stall further aggregate growth. However, owing to the levitation technique and the limited data statistics, no conclusive statement about this aspect can yet be given. We find that the detachment efficiency decreases with increasing velocities and accretion dominates in the higher velocity range. For high accretion efficiencies, our experiments suggest that continued growth in the mm-range with larger constituent grains would be a viable way to produce larger aggregates, which might in turn form the seeds to proceed to growing planetesimals.Comment: 9 pages, 20 figure

Short-term leprosy forecasting from an expert opinion survey.

We conducted an expert survey of leprosy (Hansen's Disease) and neglected tropical disease experts in February 2016. Experts were asked to forecast the next year of reported cases for the world, for the top three countries, and for selected states and territories of India. A total of 103 respondents answered at least one forecasting question. We elicited lower and upper confidence bounds. Comparing these results to regression and exponential smoothing, we found no evidence that any forecasting method outperformed the others. We found evidence that experts who believed it was more likely to achieve global interruption of transmission goals and disability reduction goals had higher error scores for India and Indonesia, but lower for Brazil. Even for a disease whose epidemiology changes on a slow time scale, forecasting exercises such as we conducted are simple and practical. We believe they can be used on a routine basis in public health

Markers of bone and lipid metabolism with eslicarbazepine acetate monotherapy.

OBJECTIVE: To evaluate the impact of eslicarbazepine acetate (ESL) monotherapy on markers of bone and lipid metabolism. METHODS: We conducted a post-hoc analysis of data pooled from two Phase III, dose-blind, conversion-to-ESL (1600 mg and 1200 mg) monotherapy studies in patients with focal seizures. Laboratory measurements included lipids (total cholesterol [TC]; high-density lipoprotein cholesterol [HDL-C]; low-density lipoprotein cholesterol; and triglycerides) and markers of bone metabolism (alkaline phosphatase; 25-hydroxyvitamin D; osteocalcin; and parathyroid hormone [PTH]); measurements were taken at baseline, Week 18, and Month 12, and analyzed according to enzyme-inducing antiepileptic drugs (EIAEDs) use at baseline (+EIAED and -EIAED subgroups). RESULTS: Data from 337 treatment-compliant patients were used for the Week 18 analyses (+EIAED subgroup, n = 119; -EIAED subgroup, n = 218); data from 161 treatment-compliant patients were used for the Month 12 analyses (+EIAED subgroup, n = 53; -EIAED subgroup, n = 108). At baseline, alkaline phosphatase and PTH concentrations were higher in the + EIAED versus -EIAED subgroup. Changes from baseline in markers of bone turnover were generally insignificant, except for some elevation in alkaline phosphatase in the -EIAED subgroup (18 weeks and 12 months) and osteocalcin in both subgroups (18 weeks only). Regarding lipids, TC and HDL-C concentrations were higher in the + EIAED versus -EIAED subgroup at baseline. Concentrations of markers of lipid metabolism fell in the + EIAED group and rose in the -EIAED group, reaching very similar values that were intermediate between the -EIAED and + EIAED baseline values. CONCLUSIONS: Based on this retrospective analysis, ESL seems to have had only a modest and primarily clinically insignificant impact on plasma lipids. More prospective data are needed to definitively ascertain the effects of ESL on bone metabolism

Effects of adjunctive eslicarbazepine acetate on serum lipids in patients with partial-onset seizures: Impact of concomitant statins and enzyme-inducing antiepileptic drugs.

PURPOSE: To evaluate the effects of eslicarbazepine acetate (ESL) on lipid metabolism and to determine whether reduced statin exposure during ESL therapy has clinical consequences. SUBJECTS AND METHODS: We conducted a post-hoc analysis of pooled data for serum lipids (laboratory values) from three phase III, multicenter, randomized, double-blind, placebo-controlled trials of adjunctive ESL therapy (400, 800, or 1200 mg once daily) in patients with treatment-refractory partial-onset seizures. Changes from baseline in serum lipid levels were analyzed according to use of statins and/or enzyme-inducing antiepileptic drugs (EIAEDs) during the baseline period. KEY FINDINGS: In total, 426 and 1021 placebo- and ESL-treated patients, respectively, were included in the analysis. With regard to the changes from baseline in serum concentrations, there were statistically significant differences between the placebo and ESL 1200 mg QD groups, for both total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-C), but the effect sizes were small (+4.1 mg/dL and +1.8 mg/dL, respectively). A small but significant difference in low-density lipoprotein cholesterol (LDL-C; -5.0 mg/dL) was observed between the ESL 400 mg QD group and the placebo group. In patients not taking a concomitant EIAED, there were no changes with ESL 400 mg QD, but modest and statistically significant increases in cholesterol fractions (TC, LDL-C and HDL-C) with ESL 800 mg QD (/dL) and ESL 1200 mg QD (/dL). ESL had no consistent effect on lipids in patients taking a concomitant EIAED. In patients taking statins during baseline, there were no clinically relevant changes in serum lipids during use of ESL, although the subgroups were small. SIGNIFICANCE: These results suggest that ESL does not appear to have clinically significant effects on serum lipids, nor does the pharmacokinetic interaction between ESL and statins have an impact on serum lipid concentrations

Montana’s Bat Acoustic Surveillance Efforts: Pre-White-Nose Syndrome (Oral Presentation and Poster)

Montana’s bat species face a wide array of conservation issues that threaten the long-term viability of these populations. The potential arrival of White-Nose Syndrome (WNS) may be the single greatest threat as mortality has exceeded 95% for some bat populations in eastern North America. A collaborative effort was initiated in 2011 to document year-round spatial and temporal activity patterns of Montana’s bats prior to WNS arrival. In the last 4 years, we have deployed a network of over 60 Song Meter ultrasonic acoustic detector/recorder stations programmed to record bat passes from sunset to sunrise year-round. Through late December of 2014, these recording stations have resulted in more than 3.9 million full spectrum sound files containing more than 12.5 terabytes of information. Processing and automated analyses have been completed for all sound files and over 30,000 bat passes have been reviewed by hand using an updated Montana bat call characteristics key to definitively confirm the presence of species during each month of the year, identify the lowest temperatures at which individual bat species are active, and track overall bat activity, regardless of species, at each station. Highlights to-date include: 1421 new records of monthly species presence throughout the state, numerous first records of species’ activity during the fall, winter, and spring months, numerous first records of species in regions with previously limited bat survey effort, documentation of nightly activity patterns throughout the year and regular winter activity for a few resident species, and the year-round presence of species previously considered migratory

Montana’s Bat Acoustic Surveillance Efforts: an Update (Poster)

Montana’s bat species face a wide array of conservation issues that threaten their long-term viability.  A collaborative effort was initiated in 2011 to document year-round activity patterns of Montana’s bats prior to the arrival of White-nose Syndrome as mortality has exceeded 95% for some bat populations effected by this disease in eastern North America.  In the last 5 years, we have deployed a network of over 76 Song Meter ultrasonic acoustic detector/recorder stations programmed to record bat passes from sunset to sunrise year-round. Through late December 2015, these recording stations have resulted in more than 7.2 million full spectrum sound files containing nearly 13 terabytes of information. Processing and automated analyses have been completed for all sound files and over 43,000 bat passes have been reviewed by hand using an updated Montana bat call characteristics key to definitively confirm the presence of species during each month of the year, identify the lowest temperatures at which individual bat species are active, and track overall bat activity, regardless of species, at each station. Highlights to-date include: 2,104 new records of monthly species presence in various landscapes across the region, numerous first records of species’ activity during the fall, winter, and spring months, numerous first records of species in regions with previously limited survey effort, documentation of nightly activity patterns throughout the year, regular winter activity for a few resident species, the year-round presence of species previously considered migratory, and exciting patterns of activity relative to temperature, wind speed, barometric pressure, and moonlight

Montana’s Bat Acoustic Surveillance Efforts: Pre-White-Nose Syndrome (Oral Presentation and Poster)

Montana’s bat species face a wide array of conservation issues that threaten the long-term viability of these populations. The potential arrival of White-Nose Syndrome (WNS) may be the single greatest threat as mortality has exceeded 95% for some bat populations in eastern North America. A collaborative effort was initiated in 2011 to document year-round spatial and temporal activity patterns of Montana’s bats prior to WNS arrival. In the last 4 years, we have deployed a network of over 60 Song Meter ultrasonic acoustic detector/recorder stations programmed to record bat passes from sunset to sunrise year-round. Through late December of 2014, these recording stations have resulted in more than 3.9 million full spectrum sound files containing more than 12.5 terabytes of information. Processing and automated analyses have been completed for all sound files and over 30,000 bat passes have been reviewed by hand using an updated Montana bat call characteristics key to definitively confirm the presence of species during each month of the year, identify the lowest temperatures at which individual bat species are active, and track overall bat activity, regardless of species, at each station. Highlights to-date include: 1421 new records of monthly species presence throughout the state, numerous first records of species’ activity during the fall, winter, and spring months, numerous first records of species in regions with previously limited bat survey effort, documentation of nightly activity patterns throughout the year and regular winter activity for a few resident species, and the year-round presence of species previously considered migratory

The effect of aqueous alteration and metamorphism in the survival of presolar silicate grains in chondrites

Relatively small amounts (typically between 2-200 parts per million) of presolar grains have been preserved in the matrices of chondritic meteorites. The measured abundances of the different types of grains are highly variable from one chondrite to another, but are higher in unequilibrated chondrites that have experienced little or no aqueous alteration and/or metamorphic heating than in processed meteorites. A general overview of the abundances measured in presolar grains (particularly the recently identified presolar silicates) contained in primitive chondrites is presented. Here we will focus on the most primitive chondrite groups, as typically the highest measured abundances of presolar grains occur in primitive chondrites that have experienced little thermal metamorphism. Looking at the most aqueously altered chondrite groups, we find a clear pattern of decreasing abundance of presolar silicate grains with increasing level of aqueous alteration. We conclude that the measured abundances of presolar grains in altered chondrites are strongly biased by their peculiar histories. Scales quantifying the intensity of aqueous alteration and shock metamorphism in chondrites could correlate with the content in presolar silicates. To do this it would be required to infer the degree of destruction or homogenization of presolar grains in the matrices of primitive meteorites. To get an unbiased picture of the relative abundance of presolar grains in the different regions of the protoplanetary disk where first meteorites consolidated, future dedicated studies of primitive meteorites, IDPs, and collected materials from sample-return missions (like e.g. the planned Marco Polo) are urgently required.Comment: 15 pages, 3 figures, published in PASA as part of the Proceedings of the 2008 Torino Conference "The Origin of the Elements Heavier than Iron

Views of young people with chronic conditions on transition from pediatric to adult health services

PURPOSE: This study sought to identify and describe the views of young people with chronic conditions about the transition from pediatric to adult services. METHODS: Q methodology was used to identify young people’s views on transition. A set of 39 statements about transition was developed from an existing literature review and refined in consultation with local groups of young people. Statements were printed onto cards and a purposive sample of 44 young people with chronic health conditions was recruited, 41 remaining in the study. The young people were asked to sort the statement cards onto a Q-sort grid, according to their opinions from “strongly disagree” to “strongly agree.” Factor analysis was used to identify shared points of view (patterns of similarity between individual’s Q-sorts). RESULTS: Four distinct views on transition were identified from young people: (1) “a laid-back view of transition;” (2) “anxiety about transition;” (3) “wanting independence and autonomy during transition;” and (4) “valuing social interaction with family, peers, and professionals to assist transition.” CONCLUSIONS: Successful transition is likely to be influenced by how young people view the process. Discussing and understanding young people’s views and preferences about transition should help clinicians and young people develop personalized planning for transition as a whole, and more specifically the point of transfer, leading to effective and efficient engagement with adult care