54 research outputs found
Differential postural effects of plantar-flexor muscles fatigue under normal, altered and improved vestibular and neck somatosensory conditions
The aim of the present study was to assess the effects of plantar-flexor
muscles fatigue on postural control during quiet standing under normal, altered
and improved vestibular and neck somatosensory conditions. To address this
objective, young male university students were asked to stand upright as still
as possible with their eyes closed in two conditions of No Fatigue and Fatigue
of the plantar-flexor muscles. In Experiment 1 (n=15), the postural task was
executed in two Neutral head and Head tilted backward postures, recognized to
degrade vestibular and neck somatosensory information. In Experiment 2 (n=15),
the postural task was executed in two conditions of No tactile and Tactile
stimulation of the neck provided by the application of strips of adhesive
bandage to the skin over and around the neck. Centre of foot pressure
displacements were recorded using a force platform. Results showed that (1) the
Fatigue condition yielded increased CoP displacements relative to the No
Fatigue condition (Experiment 1 and Experiment 2), (2) this destabilizing
effect was more accentuated in the Head tilted backward posture than Neutral
head posture (Experiment 1) and (3) this destabilizing effect was less
accentuated in the condition of Tactile stimulation than that of No tactile
stimulation of the neck (Experiment 2). In the context of the multisensory
control of balance, these results suggest an increased reliance on vestibular
and neck somatosensory information for controlling posture during quiet
standing in condition of altered ankle neuromuscular function
The TESS-Keck Survey. XI. Mass Measurements for Four Transiting Sub-Neptunes Orbiting K Dwarf TOI-1246
Multiplanet systems are valuable arenas for investigating exoplanet architectures and comparing planetary siblings. TOI-1246 is one such system, with a moderately bright K dwarf (V = 11.6, K = 9.9) and four transiting sub-Neptunes identified by TESS with orbital periods of 4.31, 5.90, 18.66, and 37.92 days. We collected 130 radial velocity observations with Keck/HIRES and TNG/HARPS-N to measure planet masses. We refit the 14 sectors of TESS photometry to refine planet radii (2.97 +/- 0.06 R (circle plus), 2.47 +/- 0.08 R (circle plus), 3.46 +/- 0.09 R (circle plus), and 3.72 +/- 0.16 R (circle plus)) and confirm the four planets. We find that TOI-1246 e is substantially more massive than the three inner planets (8.1 +/- 1.1 M (circle plus), 8.8 +/- 1.2 M (circle plus), 5.3 +/- 1.7 M (circle plus), and 14.8 +/- 2.3 M (circle plus)). The two outer planets, TOI-1246 d and TOI-1246 e, lie near to the 2:1 resonance (P (e)/P ( d ) = 2.03) and exhibit transit-timing variations. TOI-1246 is one of the brightest four-planet systems, making it amenable for continued observations. It is one of only five systems with measured masses and radii for all four transiting planets. The planet densities range from 0.70 +/- 0.24 to 3.21 +/- 0.44 g cm(-3), implying a range of bulk and atmospheric compositions. We also report a fifth planet candidate found in the RV data with a minimum mass of 25.6 +/- 3.6 M (circle plus). This planet candidate is exterior to TOI-1246 e, with a candidate period of 93.8 days, and we discuss the implications if it is confirmed to be planetary in nature
SexâSpecific Differences in Clinical Outcomes After Percutaneous Coronary Intervention: Insights from the TAILORâPCI Trial
Background TAILORâPCI (Tailored Antiplatelet Initiation to Lessen Outcomes due to decreased Clopidogrel Response After Percutaneous Coronary Intervention) studied genotypeâguided selection of antiplatelet therapy after percutaneous coronary intervention versus conventional therapy with clopidogrel. The presence of CYP2C19 lossâofâfunction alleles in patients treated with clopidogrel may be associated with increased risk for ischemic events. We report a prespecified sexâspecific analysis of genotyping and associated cardiovascular outcomes from this study. Methods and Results Associations between sex and major adverse cardiac events (MACE: cardiovascular death, myocardial infarction, stroke, stent thrombosis, and severe recurrent ischemia) and Bleeding Academic Research Consortium (BARC) bleeding at 12Â months were analyzed using Cox proportionalâhazards models. Among 5276 randomized patients, lossâofâfunction carriers were observed in â36% of both sexes, and >80% of carriers were heterozygotes. At 12Â months, after adjustment for baseline differences, risks of MACE (HR , 1.28 [0.97 to 1.68]; P=0.088) and BARC bleeding (hazard ratio [HR], 1.36 [0.91 to 2.05]; P=0.14) were comparable among women and men. There were no significant interactions between sex and treatment strategy for MACE interaction P value (Pint=0.59) or BARC bleeding (Pint=0.47) nor for sex and genotype (MACE Pint=0.15, and BARC bleeding Pint=0.60). Conclusions CYP2C19 lossâofâfunction alleles were present in â1 in 3 women and men. Women had similar adjusted risks of MACE and bleeding as men following percutaneous coronary intervention. Genotypeâguided therapy did not significantly reduce the risk of MACE or bleeding relative to conventional therapy for both sexes. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT01742117
Identifying the roles of amino acids, alcohols and 1,2-diamines as mediators in coupling of haloarenes to arenes
Coupling of haloarenes to arenes has been facilitated by a diverse range of organic additives in the presence of KO(t)Bu or NaO(t)Bu since the first report in 2008. Very recently, we showed that the reactivity of some of these additives (e.g., compounds 6 and 7) could be explained by the formation of organic electron donors in situ, but the role of other additives was not addressed. The simplest of these, alcohols, including 1,2-diols, 1,2-diamines, and amino acids are the most intriguing, and we now report experiments that support their roles as precursors of organic electron donors, underlining the importance of this mode of initiation in these coupling reactions
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