Actinide 2-metallabiphenylenes that satisfy Hückel's rule.

Aromaticity and antiaromaticity, as defined by Hückel's rule, are key ideas in organic chemistry, and are both exemplified in biphenylene1-3-a molecule that consists of two benzene rings joined by a four-membered ring at its core. Biphenylene analogues in which one of the benzene rings has been replaced by a different (4n + 2) π-electron system have so far been associated only with organic compounds4,5. In addition, efforts to prepare a zirconabiphenylene compound resulted in the isolation of a bis(alkyne) zirconocene complex instead6. Here we report the synthesis and characterization of, to our knowledge, the first 2-metallabiphenylene compounds. Single-crystal X-ray diffraction studies reveal that these complexes have nearly planar, 11-membered metallatricycles with metrical parameters that compare well with those reported for biphenylene. Nuclear magnetic resonance spectroscopy, in addition to nucleus-independent chemical shift calculations, provides evidence that these complexes contain an antiaromatic cyclobutadiene ring and an aromatic benzene ring. Furthermore, spectroscopic evidence, Kohn-Sham molecular orbital compositions and natural bond orbital calculations suggest covalency and delocalization of the uranium f2 electrons with the carbon-containing ligand.

Yoga reduces performance anxiety in adolescent musicians.

CONTEXT: Professional musicians often experience high levels of stress, music performance anxiety (MPA), and performance-related musculoskeletal disorders (PRMDs). Given the fact that most professional musicians begin their musical training before the age of 12, it is important to identify interventions that will address these issues from an early age. OBJECTIVE: This study intended to replicate and expand upon adult research in this area by evaluating the effects of a yoga intervention on MPA and PRMDs in a population of adolescent musicians. The present study was the first to examine these effects. DESIGN: The research team assigned participants, adolescent musicians, into two groups. The intervention group (n = 84) took part in a 6-wk yoga program, and the control group (n = 51) received no treatment. The team evaluated the effects of the yoga intervention by comparing the scores of the intervention group to those of the control group on a number of questionnaires related to MPA and PRMDs. SETTING: The study was conducted at the Boston University Tanglewood Institute (BUTI). BUTI is a training academy for advanced adolescent musicians, located in Lenox, Massachusetts. PARTICIPANTS: Participants were adolescent, residential music students (mean age = 16 y) in a 6-wk summer program at the BUTI in 2007 and 2008. INTERVENTION: Participants in the yoga intervention group were requested to attend three, 60-min, Kripalustyle yoga classes each wk for 6 wk. OUTCOME MEASURES: MPA was measured using the Performance Anxiety Questionnaire (PAQ) and the Music Performance Anxiety Inventory for Adolescents (MPAI-A). PRMDs were measured using the Performance-Related Musculoskeletal Disorders Questionnaire (PRMD-Q). RESULTS • Yoga participants showed statistically significant reductions in MPA from baseline to the end of the program compared to the control group, as measured by several subscales of the PAQ and MPAI-A; however, the results for PRMDs were inconsistent. CONCLUSION: The findings suggest that yoga may be a promising way for adolescents to reduce MPA and perhaps even prevent it in the future. These findings also suggest a novel treatment modality that potentially might alleviate MPA and prevent the early disruption and termination of musical careers.

Evaluation of the mental health benefits of yoga in a secondary school: a preliminary randomized controlled trial.

The goal of this study was to evaluate potential mental health benefits of yoga for adolescents in secondary school. Students were randomly assigned to either regular physical education classes or to 11 weeks of yoga sessions based upon the Yoga Ed program over a single semester. Students completed baseline and end-program self-report measures of mood, anxiety, perceived stress, resilience, and other mental health variables. Independent evaluation of individual outcome measures revealed that yoga participants showed statistically significant differences over time relative to controls on measures of anger control and fatigue/inertia. Most outcome measures exhibited a pattern of worsening in the control group over time, whereas changes in the yoga group over time were either minimal or showed slight improvements. These preliminary results suggest that implementation of yoga is acceptable and feasible in a secondary school setting and has the potential of playing a protective or preventive role in maintaining mental health.

Serendipity strikes again--efficient preparation of lithium tetramethylcuprate(III) via rapid injection NMR.

Lithium tetramethylcuprate(III), Me(4)CuLi, the Cu(III) analog of the Gilman reagent, has been prepared in high yield from halo-Gilman reagents Me(2)CuLi.LiX (X = Cl, Br, I) and 2,3-dichloropropene and found to have surprising thermal stability. The cyano-Gilman reagent (X = CN) follows a different pathway.

Yoga ameliorates performance anxiety and mood disturbance in young professional musicians.

Yoga and meditation can alleviate stress, anxiety, mood disturbance, and musculoskeletal problems, and can enhance cognitive and physical performance. Professional musicians experience high levels of stress, performance anxiety, and debilitating performance-related musculoskeletal disorders (PRMDs). The goal of this controlled study was to evaluate the benefits of yoga and meditation for musicians. Young adult professional musicians who volunteered to participate in a 2-month program of yoga and meditation were randomized to a yoga lifestyle intervention group (n = 15) or to a group practicing yoga and meditation only (n = 15). Additional musicians were recruited to a no-practice control group (n = 15). Both yoga groups attended three Kripalu Yoga or meditation classes each week. The yoga lifestyle group also experienced weekly group practice and discussion sessions as part of their more immersive treatment. All participants completed baseline and end-program self-report questionnaires that evaluated music performance anxiety, mood, PRMDs, perceived stress, and sleep quality; many participants later completed a 1-year followup assessment using the same questionnaires. Both yoga groups showed a trend towards less music performance anxiety and significantly less general anxiety/tension, depression, and anger at end-program relative to controls, but showed no changes in PRMDs, stress, or sleep. Similar results in the two yoga groups, despite psychosocial differences in their interventions, suggest that the yoga and meditation techniques themselves may have mediated the improvements. Our results suggest that yoga and meditation techniques can reduce performance anxiety and mood disturbance in young professional musicians.

Preparation of sigma- and pi-allylcopper(III) intermediates in SN2 and SN2' reactions of organocuprate(I) reagents with allylic substrates.

The first pi-allyl complexes of CuIII have been prepared and characterized by using rapid injection nuclear magnetic resonance spectroscopy (RI-NMR). The prototype, (eta3-allyl)dimethylcopper(III), was prepared by injection of allyl chloride into a THF-d8 solution of iodo-Gilman reagent, Me2CuLi.LiI (A), spinning in the probe of an NMR spectrometer at -100 degreesC. A sigma-allyl ate complex, lithium (eta1-allyl)trimethylcuprate(III), was prepared in high yield by including 1 equiv of tributylphosphine in the reaction mixture or by using allyl acetate as the substrate. Cyano ate complex, lithium cis-(eta1-allyl)cyanodimethylcuprate(III) was obtained in high yield by injecting allyl chloride or allyl acetate into the cyano-Gilman reagent, Me2CuLi.LiCN (B), in THF-d8 at -100 degrees C. Reactions of A with allylic substrates show a definite dependence on leaving group (chloride vs acetate), whereas those of B do not. Moreover, these reagents have different regioselectivities, which in the case of A vary with temperature. Finally, the exclusive formation of cis-cyano sigma-allyl CuIII intermediates in both the 1,4-addition of B to alpha-enones and its SN2alpha reaction with allylic substrates now makes sense in terms of pi-allyl intermediates in both cases, thus unifying the mechanisms of these two kinds of conjugate addition.

Neutral organocopper(III) complexes.

Neutral organocopper(III) complexes have been prepared from organocuprate(I) reagents and alkyl halides in the presence of certain strongly electron donating ligands.

Effects of a yoga lifestyle intervention on performance-related characteristics of musicians: a preliminary study.

BACKGROUND: Previous research has suggested that yoga and meditation practices are effective in stress management, alleviating anxiety and musculoskeletal problems and improving mood and cognitive and physical performance. Musicians experience a number of challenges in their profession including high levels of stress, performance anxiety and performance-related musculoskeletal conditions. Yoga and meditation techniques are therefore potentially useful practices for professional musicians. MATERIAL/METHODS: Musicians enrolled in a prestigious 2-month summer fellowship program were invited to participate in a regular yoga and meditation program at a yoga center during the course of the program. The 10 participants in the yoga program completed baseline and end-program questionnaires evaluating performance-related musculoskeletal conditions, performance anxiety, mood and flow experience. Fellows not participating in the yoga program were recruited to serve as controls and completed the same assessments (N=8). RESULTS: The yoga participants showed some improvements relative to control subjects on most measures, with the relative improvement in performance anxiety being the greatest. CONCLUSIONS: The results from this preliminary study suggest that yoga and meditation may be beneficial as a routine practice to reduce performance anxiety in musicians.