TOI-836 : a super-Earth and mini-Neptune transiting a nearby K-dwarf

Funding: TGW, ACC, and KH acknowledge support from STFC consolidated grant numbers ST/R000824/1 and ST/V000861/1, and UKSA grant ST/R003203/1.We present the discovery of two exoplanets transiting TOI-836 (TIC 440887364) using data from TESS Sector 11 and Sector 38. TOI-836 is a bright (T = 8.5 mag), high proper motion (∼200 mas yr−1), low metallicity ([Fe/H]≈−0.28) K-dwarf with a mass of 0.68 ± 0.05 M⊙ and a radius of 0.67 ± 0.01 R⊙. We obtain photometric follow-up observations with a variety of facilities, and we use these data-sets to determine that the inner planet, TOI-836 b, is a 1.70 ± 0.07 R⊕ super-Earth in a 3.82 day orbit, placing it directly within the so-called ‘radius valley’. The outer planet, TOI-836 c, is a 2.59 ± 0.09 R⊕ mini-Neptune in an 8.60 day orbit. Radial velocity measurements reveal that TOI-836 b has a mass of 4.5 ± 0.9 M⊕, while TOI-836 c has a mass of 9.6 ± 2.6 M⊕. Photometric observations show Transit Timing Variations (TTVs) on the order of 20 minutes for TOI-836 c, although there are no detectable TTVs for TOI-836 b. The TTVs of planet TOI-836 c may be caused by an undetected exterior planet.Publisher PDFPeer reviewe

TOI-836: A super-Earth and mini-Neptune transiting a nearby K-dwarf

We present the discovery of two exoplanets transiting TOI-836 (TIC 440887364) using data from TESS Sector 11 and Sector 38. TOI-836 is a bright ($T = 8.5$ mag), high proper motion ($\sim\,200$ mas yr$^{-1}$), low metallicity ([Fe/H]$\approx\,-0.28$) K-dwarf with a mass of $0.68\pm0.05$ M$_{\odot}$ and a radius of $0.67\pm0.01$ R$_{\odot}$. We obtain photometric follow-up observations with a variety of facilities, and we use these data-sets to determine that the inner planet, TOI-836 b, is a $1.70\pm0.07$ R$_{\oplus}$ super-Earth in a 3.82 day orbit, placing it directly within the so-called 'radius valley'. The outer planet, TOI-836 c, is a $2.59\pm0.09$ R$_{\oplus}$ mini-Neptune in an 8.60 day orbit. Radial velocity measurements reveal that TOI-836 b has a mass of $4.5\pm0.9$ M$_{\oplus}$ , while TOI-836 c has a mass of $9.6\pm2.6$ M$_{\oplus}$. Photometric observations show Transit Timing Variations (TTVs) on the order of 20 minutes for TOI-836 c, although there are no detectable TTVs for TOI-836 b. The TTVs of planet TOI-836 c may be caused by an undetected exterior planet

TOI-836: A super-Earth and mini-Neptune transiting a nearby K-dwarf

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Effect of remote ischaemic conditioning on clinical outcomes in patients with acute myocardial infarction (CONDI-2/ERIC-PPCI): a single-blind randomised controlled trial.

BACKGROUND: Remote ischaemic conditioning with transient ischaemia and reperfusion applied to the arm has been shown to reduce myocardial infarct size in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI). We investigated whether remote ischaemic conditioning could reduce the incidence of cardiac death and hospitalisation for heart failure at 12 months. METHODS: We did an international investigator-initiated, prospective, single-blind, randomised controlled trial (CONDI-2/ERIC-PPCI) at 33 centres across the UK, Denmark, Spain, and Serbia. Patients (age >18 years) with suspected STEMI and who were eligible for PPCI were randomly allocated (1:1, stratified by centre with a permuted block method) to receive standard treatment (including a sham simulated remote ischaemic conditioning intervention at UK sites only) or remote ischaemic conditioning treatment (intermittent ischaemia and reperfusion applied to the arm through four cycles of 5-min inflation and 5-min deflation of an automated cuff device) before PPCI. Investigators responsible for data collection and outcome assessment were masked to treatment allocation. The primary combined endpoint was cardiac death or hospitalisation for heart failure at 12 months in the intention-to-treat population. This trial is registered with ClinicalTrials.gov (NCT02342522) and is completed. FINDINGS: Between Nov 6, 2013, and March 31, 2018, 5401 patients were randomly allocated to either the control group (n=2701) or the remote ischaemic conditioning group (n=2700). After exclusion of patients upon hospital arrival or loss to follow-up, 2569 patients in the control group and 2546 in the intervention group were included in the intention-to-treat analysis. At 12 months post-PPCI, the Kaplan-Meier-estimated frequencies of cardiac death or hospitalisation for heart failure (the primary endpoint) were 220 (8·6%) patients in the control group and 239 (9·4%) in the remote ischaemic conditioning group (hazard ratio 1·10 [95% CI 0·91-1·32], p=0·32 for intervention versus control). No important unexpected adverse events or side effects of remote ischaemic conditioning were observed. INTERPRETATION: Remote ischaemic conditioning does not improve clinical outcomes (cardiac death or hospitalisation for heart failure) at 12 months in patients with STEMI undergoing PPCI. FUNDING: British Heart Foundation, University College London Hospitals/University College London Biomedical Research Centre, Danish Innovation Foundation, Novo Nordisk Foundation, TrygFonden

Differences in Competitive Ability between Plants from Nonnative and Native Populations of a Tropical Invader Relates to Adaptive Responses in Abiotic and Biotic Environments

<div><p>The evolution of competitive ability of invasive plant species is generally studied in the context of adaptive responses to novel biotic environments (enemy release) in introduced ranges. However, invasive plants may also respond to novel abiotic environments. Here we studied differences in competitive ability between <i>Chromolaena odorata</i> plants of populations from nonnative versus native ranges, considering biogeographical differences in both biotic and abiotic environments. An intraspecific competition experiment was conducted at two nutrient levels in a common garden. In both low and high nutrient treatments, <i>C. odorata</i> plants from nonnative ranges showed consistently lower root to shoot ratios than did plants from native ranges grown in both monoculture and competition. In the low nutrient treatment, <i>C. odorata</i> plants from nonnative ranges showed significantly lower competitive ability (competition-driven decreases in plant height and biomass were more), which was associated with their lower root to shoot ratios and higher total leaf phenolic content (defense trait). In the high nutrient treatment, <i>C. odorata</i> plants from nonnative ranges showed lower leaf toughness and cellulosic contents (defense traits) but similar competitive ability compared with plants from native ranges, which was also associated with their lower root to shoot ratios. Our results indicate that genetically based shifts in biomass allocation (responses to abiotic environments) also influence competitive abilities of invasive plants, and provide a first potential mechanism for the interaction between range and environment (environment-dependent difference between ranges).</p></div

Differences in biomass between <i>Chromolaena odorata</i> plants of the populations from native versus nonnative ranges.

<p>Panels A and B were for plants grown in monoculture, and panels C and D were for plants grown in competition. Panels A and C were for plants grown at low nutrient level, and panels B and D were for plants grown at high nutrient level. Narrow bars depict means and SE for each population; two thicker bars in the center are means and SE for all populations from each range. * indicates significant difference between ranges at each nutrient level according to one-way nested ANCOVA (<i>P</i><0.05; Tables S2, S4 in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0071767#pone.0071767.s001" target="_blank">File S1</a>).</p

Differences in leaf toughness and phenolics between <i>Chromolaena odorata</i> plants of the populations from native versus nonnative ranges.

<p>Panels A and C were for plants grown at low nutrient level (monoculture), and panels B and D were for plants grown at high nutrient level (monoculture). Narrow bars depict means and SE for each population; two thicker bars in the center are means and SE for all populations from each range. * indicates significant difference between ranges at each nutrient level according to one-way nested ANOVA (<i>P</i><0.05; Tables S3, S5 in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0071767#pone.0071767.s001" target="_blank">File S1</a>).</p

Differences in leaf cellulose and hemicellulose between <i>Chromolaena odorata</i> plants of the populations from native versus nonnative ranges.

<p>Panels A and C were for plants grown under low nutrient level (monoculture), and panels B and D were for plants grown under high nutrient level (monoculture). Narrow bars depict means and SE for each population; two thicker bars in the center are means and SE for all populations from each range. * indicates significant difference between ranges at each nutrient level according to one-way nested ANOVA (<i>P</i><0.05; Tables S3, S5 in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0071767#pone.0071767.s001" target="_blank">File S1</a>).</p

Differences in height between <i>Chromolaena odorata</i> plants of the populations from native versus nonnative ranges.

<p>Panels A and B were for plants grown in monoculture, and panels C and D were for plants grown in competition. Panels A and C were for plants grown at low nutrient level, and panels B and D were for plants grown at high nutrient level. Narrow bars depict means and SE for each population; two thicker bars in the center are means and SE for all populations from each range. * indicates significant difference between ranges at each nutrient level according to one-way nested ANCOVA (<i>P</i><0.05; Tables S2, S4 in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0071767#pone.0071767.s001" target="_blank">File S1</a>).</p

Differences in root to shoot ratios between <i>Chromolaena odorata</i> plants of the populations from native versus nonnative ranges.

<p>Panels A and B were for plants grown in monoculture, and panels C and D were for plants grown in competition. Panels A and C were for plants grown at low nutrient level, and panels B and D were for plants grown at high nutrient level. Narrow bars depict means and SE for each population; two thicker bars in the center are means and SE for all populations from each range. * indicates significant difference between ranges at each nutrient level according to one-way nested ANCOVA (<i>P</i><0.05; Tables S2, S4 in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0071767#pone.0071767.s001" target="_blank">File S1</a>).</p