5,449 research outputs found
Kinetics and Products of the Acid-Catalyzed Ring-Opening of Atmospherically Relevant Butyl Epoxy Alcohols
Epoxydiols are produced in the gas phase from the photo-oxidation of isoprene in the absence of significant mixing ratios of nitrogen oxides (NO_x). The reactive uptake of these compounds onto acidic aerosols has been shown to produce secondary organic aerosol (SOA). To better characterize the fate of isoprene epoxydiols in the aerosol phase, the kinetics and products of the acid-catalyzed ring-opening reactions of four hydroxy-substituted epoxides were studied by nuclear magnetic resonance (NMR) techniques. Polyols and sulfate esters are observed from the ring-opening of the epoxides in solutions of H_2SO_4/Na_2SO_4. Likewise, polyols and nitrate esters are produced in solutions of HNO_3/NaNO_3. In sulfuric acid, the rate of acid-catalyzed ring-opening is dependent on hydronium ion activity, sulfate ion, and bisulfate. The rates are much slower than the nonhydroxylated equivalent epoxides; however, the hydroxyl groups make them much more water-soluble. A model was constructed with the major channels for epoxydiol loss (i.e., aerosol-phase ring-opening, gas-phase oxidation, and deposition). In the atmosphere, SOA formation from epoxydiols will depend on a number of variables (e.g., pH and aerosol water content) with the yield of ring-opening products varying from less than 1% to greater than 50%
Domestic Support for the U.S. Rice Sector and the WTO: Implications of the 2002 Farm Act
The U.S. rice sector is expected to receive some of the largest relative support under the 2002 Farm Act. USDA's rice baseline model is used to compute marketing loan benefits, while direct payments and counter-cyclical payments are estimated from endogenous prices and exogenous policy parameters. Alternative scenarios of reduced marketing loan benefits suggest that projected annual average sector revenue could decline by 4 to 27 percent.Agricultural and Food Policy,
Anti-CTLA-4 (CD 152) monoclonal antibody-induced autoimmune interstitial nephritis
Targeted immune-modulating agents are entering clinical practice in many specialties, providing novel therapeutic possibilities but introducing new potential toxicities. We present the first reported case, to our knowledge, of immune-mediated nephritis following the administration of Tremelimumab (CP-675, 206), an anti-cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) monoclonal antibody. High-dose steroid therapy led to a rapid improvement in renal function, avoiding the need for renal replacement therapy.Peer reviewe
The Origin and Universality of the Stellar Initial Mass Function
We review current theories for the origin of the Stellar Initial Mass
Function (IMF) with particular focus on the extent to which the IMF can be
considered universal across various environments. To place the issue in an
observational context, we summarize the techniques used to determine the IMF
for different stellar populations, the uncertainties affecting the results, and
the evidence for systematic departures from universality under extreme
circumstances. We next consider theories for the formation of prestellar cores
by turbulent fragmentation and the possible impact of various thermal,
hydrodynamic and magneto-hydrodynamic instabilities. We address the conversion
of prestellar cores into stars and evaluate the roles played by different
processes: competitive accretion, dynamical fragmentation, ejection and
starvation, filament fragmentation and filamentary accretion flows, disk
formation and fragmentation, critical scales imposed by thermodynamics, and
magnetic braking. We present explanations for the characteristic shapes of the
Present-Day Prestellar Core Mass Function and the IMF and consider what
significance can be attached to their apparent similarity. Substantial
computational advances have occurred in recent years, and we review the
numerical simulations that have been performed to predict the IMF directly and
discuss the influence of dynamics, time-dependent phenomena, and initial
conditions.Comment: 24 pages, 6 figures. Accepted for publication as a chapter in
Protostars and Planets VI, University of Arizona Press (2014), eds. H.
Beuther, R. S. Klessen, C. P. Dullemond, Th. Hennin
Competency-based training in the supervision of relational telemental supervision
Supervision has long been considered essential to developing effective mental health practice, especially among COAMFTE accredited training programs. But with telemental health rapidly being accepted as a standard treatment medium for couple and family therapy, there is little guidance about how to supervise clinicians who are engaged in telemental health practice. This paper presents an important step toward increasing the effectiveness of the supervision of therapists who are delivering relational therapies online through the identification of relational competencies unique to this delivery medium. These competencies have been adopted and integrated into a COAMFTE accredited master\u27s degree program that has been providing training in telemental health since 2008. The competencies are described, and supervision strategies that can be utilized and developmentally assessed throughout the program will be detailed
COLLABORATIVE CARE AT A DISTANCE: STUDENT THERAPISTS’ EXPERIENCES OF LEARNING AND DELIVERING RELATIONALLY FOCUSED TELEMENTAL HEALTH
There is mounting evidence that telemental health is an effective delivery method for treating a variety of mental, emotional, behavioral, and relational health problems. While many of the therapeutic skills leading to the effectiveness of face-to-face treatments are transferable, the effectiveness of telemental health requires unique skills. The purpose of this phenomenological study was to determine the experience of learning how to use videoconferencing to deliver relationally focused mental health care. Participants included 10 graduates of a COAMFTE-accredited master’s degree program emphasizing training in telemental health. Each student had practicum placements that required videoconferencing to deliver relationally based psychotherapy. Analysis of interview data revealed (a) personal reservations about distance delivery; (b) the importance of scaffolding student learning through curriculum, supervision, and mental health-care delivery protocols; (c) the technological barriers associated with this delivery method; and (d) overcoming technological barriers through intentionality
A Knock-In Mouse Model for the R120G Mutation of αB-Crystallin Recapitulates Human Hereditary Myopathy and Cataracts
An autosomal dominant missense mutation in αB-crystallin (αB-R120G) causes cataracts and desmin-related myopathy, but the underlying mechanisms are unknown. Here, we report the development of an αB-R120G crystallin knock-in mouse model of these disorders. Knock-in αB-R120G mice were generated and analyzed with slit lamp imaging, gel permeation chromatography, immunofluorescence, immunoprecipitation, histology, and muscle strength assays. Wild-type, age-matched mice were used as controls for all studies. Both heterozygous and homozygous mutant mice developed myopathy. Moreover, homozygous mutant mice were significantly weaker than wild-type control littermates at 6 months of age. Cataract severity increased with age and mutant gene dosage. The total mass, precipitation, and interaction with the intermediate filament protein vimentin, as well as light scattering of αB-crystallin, also increased in mutant lenses. In skeletal muscle, αB-R120G co-aggregated with desmin, became detergent insoluble, and was ubiquitinated in heterozygous and homozygous mutant mice. These data suggest that the cataract and myopathy pathologies in αB-R120G knock-in mice share common mechanisms, including increased insolubility of αB-crystallin and co-aggregation of αB-crystallin with intermediate filament proteins. These knock-in αB-R120G mice are a valuable model of the developmental and molecular biological mechanisms that underlie the pathophysiology of human hereditary cataracts and myopathy
4-Ď€-Photocyclization of 1,2-Dihydropyridazines: An Approach to Bicyclic 1,2-Diazetidines with Rich Synthetic Potential.
The 4-Ď€-photocyclization of a range of 1,2-dihydropyridazines is described, generating bicyclic 1,2-diazetidines in high yields on multigram scale. The key bicyclic 1,2-diazetidines are versatile synthetic intermediates and were easily converted into a range of novel derivatives, including functionalized 1,2-diazetidines, cyclobutenes, cyclobutanes, and 1,3-dienes
- …