7,766 research outputs found
Nonexistence of large nuclei in the liquid drop model
We give a simplified proof of the nonexistence of large nuclei in the liquid
drop model and provide an explicit bound. Our bound is within a factor of 2.3
of the conjectured value and seems to be the first quantitative result.Comment: 3 pages; new version with improved bound and simplified proo
Kinetics of the photosubstitution of cis-bis(benzonitrile)dichloroplatinum(II) in chloroform
Under 254 nm irradiation cis-[Pt(C6H5CN)2Cl2] is converted to H2PtCl6. Absorption of light by both the metal complex and the solvent contribute to the first step of this process, suggested to form HPt(C6H5CN) Cl3. A linear dependence of the reaction rate on light intensity appears to rule out chlorination by trichloromethyl radicals. However, at higher light intensities a higher order dependence on intensity develops, and under 313 nm irradiation is dominant, and a reaction between trichloromethyl radical and the excited state complex is proposed to account for this
The Evaluation of Mefloquine Drug Repurposing on Acute Myeloid Leukemia
The aim of this study is to observe cell proliferation, cell viability, apoptosis, and autophagy on acute myeloid leukemia (AML) cell lines, NB4 and U937, with the drug repurposing of mefloquine (MQ). Methods such as the 3-(4,5-Dimethylthiazol-2-Yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay and trypan blue staining have shown a decrease in live cells with high concentrations of mefloquine. Using their average perspective IC50 values of MQ concentration, Western blotting was applied by means of apoptosis and autophagy markers to determine if the induction of apoptosis and inhibition of autophagy was present in MQ-treated AML cells. The experiment will be continued with more cell lines, drugs, and other means of protocol in order to contribute to cancer therapy.https://scholarscompass.vcu.edu/uresposters/1285/thumbnail.jp
A kinetic study of the photolysis of tris(2,4-pentanedionato)cobalt(III) and bis(2,4-pentanedionato)cobalt(II) in chloroform
Under 254nm irradiation in chloroform, Co(acac)3 (Hacac = 2,4-pentanedione) is converted to Co(acac)2 and then to CoCl2. The metal complex is the primary photoactive species in the photoreduction of Co(acac)3, but the photosubstitution of Co(acac)2 appears to occur primarily through absorption of light by the solvent, followed by a chain reaction in which chlorine atoms displace pentanedionyl radicals. The photosubstitution rate law is complex, and the apparent quantum yield (based on total light absorbed) varies with incident light intensity and Co(acac)2 concentration, reaching values as high as 16 under the conditions of this study. Referred only to the light absorbed by CHCL3, the highest quantum yield measured was 150. An observed partial inverse dependence of the photosubstitution rate on the initial concentration of Co(acac)2 is explained in terms of a mechanism in which the pentanedione product competes with Co(acac)2 for an intermediate
An assessment of the construct validity of environmental strategy measures
The natural resource-based view of the company is emerging as a dominant paradigm for understanding the intersection of strategic management and the natural environment. Companies that proactively incorporate a natural environment perspective into their enterprise strategies are said to have sustainable competitive advantages. However, defining and measuring environmental strategy has been challenging, with different approaches yielding inconsistent results. Many studies ignore the empirical difficulties of marrying the theoretical connection between the company's resource base and environmental strategy, and its impact on environmental company performance. In this paper, we apply an inductive approach to derive a measure of environmental strategy theoretically congruent with the natural resource-based-view of the firm. We assess its reliability and, using a multi-trait multi-method matrix, confirm the convergent and discriminant validities of this measure against other measures often used by researchers. We also establish predictive validity of our environmental strategy measure for environmental performance. We discuss the implications of the measure for future research and practice.environmental performance; environmental strategies; inductive study; measures;
Evaluating the Effects of a Teacher-Implemented Mindfulness-Based Intervention on Teacher Stress and Student Prosocial Behavior
High levels of teacher stress have a negative impact on teacher performance, maintenance, and student outcomes. Given the escalation in teacher stress levels, it is important to decrease teacher stress to improve their wellbeing. One intervention that has received growing attention in reducing teacher stress is mindfulness training. However, few studies have focused on teachers implementing mindfulness-based interventions (MBIs) both with themselves and with school-age children within their classrooms. Additionally, few studies have examined the fidelity, feasibility, and social validity of teacher-implemented MBIs in a classroom setting. Through a single-case multiple baseline design across four teachers, the current study evaluated the effects of an MBI consisting of self-practice and classroom-based implementation on teacher stress and students’ classroom behavior. The study also explored implementation fidelity and whether cultural adaptations to this MBI were socially valid for teachers. Results indicated that the MBI seemed to decrease teacher stress for 2 of the 4 teachers and improved coping abilities for 2 of 4 teachers. In addition, the MBI had small yet desirable effects on students’ academic engagement, respectful behavior, and disruptive behavior in the classroom. Teacher reports suggest that MBI self-practice and classroom-based implementation were conducted with high fidelity and had strong socially validity. Results have practical implications for informing future research related to using MBI to reduce teacher stress and improve students’ classroom behavior
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