Pharmacological studies have led to a model in which the phytohormone abscisic acid (ABA) may be positively transduced via protein phosphatases of the type 1 (PP1) or type 2A (PP2A) families. However, pharmacological evidence also exists that PP1s or PP2As may function as negative regulators of ABA signaling. Furthermore, recessive disruption mutants in protein phosphatases that function in ABA signal transduction have not yet been identified. A guard cell-expressed PP2A gene, RCN1, which had been characterized previously as a molecular component affecting auxin transport and gravity response, was isolated. A T-DNA disruption mutation in RCN1 confers recessive ABA insensitivity to Arabidopsis. The rcn1 mutation impairs ABA-induced stomatal closing and ABA activation of slow anion channels. Calcium imaging analyses show a reduced sensitivity of ABA-induced cytosolic calcium increases in rcn1, whereas mechanisms downstream of cytosolic calcium increases show wild-type responses, suggesting that RCN1 functions in ABA signal transduction upstream of cytosolic Ca(2+) increases. Furthermore, rcn1 shows ABA insensitivity in ABA inhibition of seed germination and ABA-induced gene expression. The PP1 and PP2A inhibitor okadaic acid phenocopies the rcn1 phenotype in wild-type plants both in ABA-induced cytosolic calcium increases and in seed germination, and the wild-type RCN1 genomic DNA complements rcn1 phenotypes. These data show that RCN1 functions as a general positive transducer of early ABA signaling.
Fundamental studies of chemical reactions often draw molecular dynamics along a reaction coordinate in a calculated or suggested potential energy surface (PES) 1-5 . But fully mapping such dynamics experimentally, by following all nuclear motions in a timeresolved manner, that is the motions of wavepackets, is challenging and has not even been realized for the simple stereotypical bimolecular reaction 6-8 of A-B + C → A + B-C. Here we report such tracking of vibrational wavepacket trajectories during photo-induced bond formation in the gold trimer complex [Au(CN)2 -]3 in an aqueous solution, using femtosecond x-ray solution scattering (liquidography 9-12 ) at x-ray free electron lasers 13,14 . We find that the complex forms from an assembly of three monomers A, B and C clustered together through non-covalent interactions 15,16 and with the distance between A and B shorter than between B and C. Tracking of the wavepacket in three-dimensional nuclear coordinates (RAB, RBC, and RAC) reveals that within the first 60 fs after photoexcitation, a covalent bond forms between A and B to give A-B + C. The second covalent bond, between B and C, subsequently forms within 360 fs to give a linear and covalently-bonded trimer complex A-B-C. The trimer exhibits harmonic vibrations that we are also able to map, and unambiguously assign to specific normal modes using only the experimental data. More intense x-rays can in principle visualize the motion of not only highly-scattering atoms such as gold but also of lighter atoms such as carbon and nitrogen, which will open the door for the direct tracking of the atomic motions involved in many chemical reactions.The [Au(CN)2 -]3 complex has served as a valuable model system for studying photoinitiated processes in solution. Irradiation with ultraviolet light excites it from the ground state (S0) to the singlet state (S1), which within 20 fs undergoes intersystem crossing to reach a triplet excited state (T1') 18 . A further transition from T1' to another triplet excited state (T1) then occurs with a time constant of 1~2 ps, completing formation of covalent bonds and transformation of the complex from a bent to a linear structure 9,17,18 (see the Supplementary Information (SI) for details of the notations of electronic states).Formation of the bonds could involve any of the three possible candidate trajectories sketched in Fig. 1b. The equilibrium structure in the ground state determines the position of the
Disturbances in circadian rhythms have been suggested as a possible cause of bipolar disorder (BD). Included in this study were 31 mood episodes of 26 BD patients, and 18 controls. Circadian rhythms of BD were evaluated at admission, at 2-week intervals during hospitalization, and at discharge. All participants wore wrist actigraphs during the studies. Saliva and buccal cells were obtained at 8:00, 11:00, 15:00, 19:00, and 23:00 for two consecutive days. Collected saliva and buccal cells were used for analysis of the cortisol and gene circadian rhythm, respectively. Circadian rhythms had different phases during acute mood episodes of BD compared to recovered states. In 23 acute manic episodes, circadian phases were ~ 7 hour advanced (equivalent to ~ 17 hour delayed). Phases of 21 out of these 23 cases returned to normal by ~ 7 hour delay along with treatment, but two out of 23 cases returned to normal by ~ 17 hour advance. In three cases of mixed manic episodes, the phases were ~ 6–7 hour delayed. For five cases of depressive episodes, circadian rhythms phases were ~ 4–5 hour delayed. After treatment, circadian phases resembled those of healthy controls. Circadian misalignment due to circadian rhythm phase shifts might be a pathophysiological mechanism of BD.
ObjectiveThe purpose of this study was to evaluate the applicability of data obtained from a wearable activity tracker (Fitbit Charge HR) to medical research. This was performed by comparing the wearable activity tracker (Fitbit Charge HR) with actigraphy (Actiwatch 2) for sleep evaluation and circadian rest-activity rhythm measurement.MethodsSixteen healthy young adults (female participants, 62.5%; mean age, 22.8 years) wore the Fitbit Charge HR and the Actiwatch 2 on the same wrist; a sleep log was recorded over a 14-day period. We compared the sleep variables and circadian rest-activity rhythm measures with Wilcoxon signed-rank tests and Spearman's correlations.ResultsThe periods and acrophases of the circadian rest-activity rhythms and the sleep start times did not differ and correlated significantly between the Fitbit Charge HR and the Actiwatch 2. The Fitbit Charge HR tended to overestimate the sleep durations compared with the Actiwatch 2. However, the sleep durations showed high correlation between the two devices for all days.ConclusionWe found that the Fitbit Charge HR showed high accuracy in sleep evaluation and circadian rest-activity rhythm measurement when compared with actigraphy for healthy young adults. The results suggest that the Fitbit Charge HR could be applicable on medical research as an alternative tool to actigraphy for sleep evaluation and measurement of the circadian rest-activity rhythm.
Neutral gold clusters, Au (n = 2-8), were optimized using coupled cluster singles and doubles with perturbative triples (CCSD(T)) with a triple-ζ-level basis set to develop reliable reference values for their structural and energy parameters in order to assess the performance of density functionals. The performance of 44 density functional theory (DFT) methods for calculating molecular structures and relative energies is assessed with respect to CCSD(T). In addition, their performance when calculating vertical ionization potentials (vIPs) of Au (n = 2-8) is also assessed by comparison with experimental values. The revTPSS functional shows good performance for calculating both the structural and energy properties of Au (n = 2-8), whereas B3P86 shows a remarkable performance in calculating the vIPs. The quadruple-ζ-level valence basis set is necessary for obtaining accurate energy values in CCSD(T) calculations.
Background: The increased prevalence of obesity has led to increases in the prevalence of chronic diseases worldwide. There is interest whether probiotics have an effect on obesity, but the effectiveness and safety of only a few probiotics for the treatment of obesity have been reported. The purpose of this study was to investigate whether ingestion of Lactobacillus sakei (CJLS03) derived from kimchi causes weight loss in people with obesity. Methods: This randomized, double-blind, placebo-controlled, clinical trial involved 114 adults with a body mass index (BMI) ≥25 kg/m 2 who were assigned randomly to a CJLS03 or placebo group. The groups received two allocations of either 5×10 9 colonyforming units of CJLS03/allocation or the equivalent vehicle for 12 weeks. Demographic and biochemical parameters, and body composition including fat and muscle mass were measured at baseline and after 12 weeks. Changes in body fat, weight, and waist circumference were compared between the two treatment groups. Adverse events were monitored during study period. Results: Body fat mass decreased by 0.2 kg in the CJLS03 group and increased by 0.6 kg in the placebo group (0.8 kg difference, P=0.018). After the 12 weeks, waist circumference was 0.8 cm smaller in the CJLS03 group than in the placebo group (P=0.013). BMI and body weight did not change after the 12 weeks. Adverse events were mild and did not differ between the two groups. Conclusion: These data suggest that L. sakei (CJLS03) might help people with obesity reduce body fat mass without serious side effects (ClinicalTrials.gov: NCT03248414).
Seasonal affective disorder (SAD) is a condition of seasonal mood changes characterized by recurrent depression in autumn or winter that spontaneously remits in spring or summer. Evidence has suggested that circadian gene variants contribute to the pathogenesis of SAD. In this study, we investigated polymorphisms in the CLOCK, ARNTL, and NPAS2 genes in relation to seasonal variation in 507 healthy young adults. Seasonal variations were assessed with the Seasonality Pattern Assessment Questionnaire. The prevalence of SAD was 12.0% (winter-type 9.3%, summer-type 2.8%). No significant difference was found between the groups in the genotype distribution of ARNTL rs2278749 and NPAS2 rs2305160. The T allele of CLOCK rs1801260 was significantly more frequent in seasonals (SAD + subsyndromal SAD) compared with non-seasonals (p = 0.020, odds ratio = 1.89, 95% confidence interval = 1.09-3.27). Global seasonality score was significantly different among genotypes of CLOCK rs1801260, but not among genotypes of ARNTL rs2278749 and NPAS2 rs2305160. However, statistical difference was observed in the body weight and appetite subscales among genotypes of ARNTL rs2278749 and in the body weight subscale among genotypes of NPAS2 rs2305160. There was synergistic interaction between CLOCK rs1801260 and ARNTL rs2278749 on seasonality. To our knowledge, this study is the first to reveal an association between the CLOCK gene and seasonal variations in mood and behavior in the Korean population. Although we cannot confirm previous findings of an association between SAD and the ARNTL and NPAS2 genes, these genes may influence seasonal variations through metabolic factors such as body weight and appetite. The interaction of the CLOCK and ARNTL genes contributes to susceptibility for SAD.
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