1. Exotic invasive plants can have strong effects on native communities. Centaurea maculosa, a forb that is native to Eurasia, has created near-monocultures in many parts of its invaded range in ...western North America and produces the root exudate (±)-catechin. Controlled laboratory experiments suggest that the phytotoxic effects of (±)-catechin may be stronger on some North American species than on some European species. 2. We conducted experiments in the field in two different years in the native (Romania) and invaded (MT, USA) ranges of C. maculosa, testing the effects of (±)-catechin on species that co-occur with C. maculosa in both ranges. 3. (±)-Catechin reduced the growth of native plant species in Montana in both years, although there was some variability between species in the effect of (±)-catechin on leaf growth in 2005. There was no effect of (±)-catechin on plants in Romania. 4. This first in situ test of the novel weapons hypothesis supports the notion that novel biochemical constituents of some invasive species may contribute to their success. 5. Synthesis. In addition to providing information useful for understanding invasions, our results indicate that some species in the native range of C. maculosa may be adapted to its particular biochemical traits, raising the possibility that interactions among plant species may be affected by a common evolutionary history.
Clinical trials have demonstrated safety and efficacy of intravenous (IV) onasemnogene abeparvovec (OA) in patients with spinal muscular atrophy (SMA) weighing <8.5 kg. SMART is a phase 3b study to ...evaluate the safety, tolerability, and efficacy of IV OA over 52 weeks for patients weighing ≥8.5 to ≤21 kg. We present interim results representing 6 months of follow-up data. Of 24 enrolled patients, 7, 8, and 9 were in the 8.5–13 kg, >13–17 kg, and >17–21 kg weight groups, respectively. 19 discontinued prior nusinersen; 2 discontinued prior risdiplam; 3 were treatment-naïve. No study withdrawals or deaths have occurred. All patients had ≥1 TEAE; 14 (58%) had ≥1 SAE; 7 (29%) had SAEs related to OA. 20/24 patients had hepatic events. The majority were asymptomatic transaminase increases and 21 reported ALT increases (2 Grade 2; 14 Grade 3; 5 Grade 4). Grade 1 transaminase elevations were ongoing in 18/24. No bilirubin elevations or Hy's law cases were observed. Prophylactic steroids were used over a median of 168.5 days. Transient asymptomatic thrombocytopenia occurred in 17/24 patients. 20/24 patients had platelet count decreases; all resolved with no reported bleeding events. 3/24 patients (13%) had cardiac AEs (all unrelated to OA). No events of thrombotic microangiopathy or dorsal root ganglionopathy were observed. Frequency/severity of AEs were similar across weight groups. Motor function (RULM, HFMSE, and motor milestones) was maintained in most patients. Mean (SD) change from baseline at Week 26 was 3.2 (4.1) and 2.3 (2.7) for HFMSE and RULM, respectively. By Week 26, 3/24 patients had achieved new motor milestones (2 received prior DMT; 1 was treatment-naïve). The safety profile of OA was similar across weight groups. Frequency of asymptomatic aminotransferase elevations and thrombocytopenia are notable findings in this interim analysis. Most patients demonstrated maintenance of motor function, suggesting clinical benefit of IV OA for heavier patients with SMA.
Rate coefficients for the dehydration of isobutanol have been determined experimentally from comparative rate single pulse shock tube measurements and calculated via multistructural transition state ...theory (MS-TST). They are represented by the Arrhenius expression, k(isobutanol → isobutene + H2O)experimental = 7.2 × 1013 exp(−35300 K/T) s–1. The theoretical work leads to the high pressure rate expression, k(isobutanol → isobutene + H2O)theory = 3.5 × 1013 exp(−35400 K/T) s–1. Results are thus within a factor of 2 of each other. The experimental results cover the temperature range 1090–1240 K and pressure range 1.5–6 atm, with no discernible pressure effects. Analysis of these results, in combination with earlier single pulse shock tube work, made it possible to derive the governing factors that control the rate coefficients for alcohol dehydration in general. Alcohol dehydration rate constants depend on the location of the hydroxyl group (primary, secondary, and tertiary) and the number of available H-atoms adjacent to the OH group for water elimination. The position of the H-atoms in the hydrocarbon backbone appears to be unimportant except for highly substituted molecules. From these correlations, we have derived k(isopropanol → propene + H2O) = 7.2 × 1013 exp(−33000 K/T) s–1. Comparison of experimental determination with theoretical calculations for this dehydration, and those for ethanol show deviations of the same magnitude as for isobutanol. Systematic differences between experiments and theoretical calculations are common.
Gaia Data Release 1 van Leeuwen, F; Evans, D W; De Angeli, F ...
Astronomy and astrophysics (Berlin),
03/2017, Letnik:
599
Journal Article
Recenzirano
Odprti dostop
Context. This paper presents an overview of the photometric data that are part of the first Gaia data release. Aims. The principles of the processing and the main characteristics of the Gaia ...photometric data are presented. Methods. The calibration strategy is outlined briefly and the main properties of the resulting photometry are presented. Results. Relations with other broadband photometric systems are provided. The overall precision for the Gaia photometry is shown to be at the milli-magnitude level and has a clear potential to improve further in future releases.
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