877 research outputs found
Tumor suppression by p53 in the absence of Atm.
Oncogenes can induce p53 through a signaling pathway involving p19/Arf. It was recently proposed that oncogenes can also induce DNA damage, and this can induce p53 through the Atm DNA damage pathway. To assess the relative roles of Atm, Arf, and p53 in the suppression of Ras-driven tumors, we examined susceptibility to skin carcinogenesis in 7,12-dimethylbenz(a)anthracene/12-O-tetradecanoylphorbol-13-acetate (TPA)-treated Atm- and p53-deficient mice and compared these results to previous studies on Arf-deficient mice. Mice with epidermal-specific deletion of p53 showed increased papilloma number and progression to malignant invasive carcinomas compared with wild-type littermates. In contrast, Atm-deficient mice showed no increase in papilloma number, growth, or malignant progression. gamma-H2AX and p53 levels were increased in both Atm(+/+) and Atm(-/-) papillomas, whereas Arf(-/-) papillomas showed much lower p53 expression. Thus, although there is evidence of DNA damage, signaling through Arf seems to regulate p53 in these Ras-driven tumors. In spontaneous and radiation-induced lymphoma models, tumor latency was accelerated in Atm(-/-)p53(-/-) compound mutant mice compared with the single mutant Atm(-/-) or p53(-/-) mice, indicating cooperation between loss of Atm and loss of p53. Although p53-mediated apoptosis was impaired in irradiated Atm(-/-) lymphocytes, p53 loss was still selected for during lymphomagenesis in Atm(-/-) mice. In conclusion, in these models of oncogene- or DNA damage-induced tumors, p53 retains tumor suppressor activity in the absence of Atm
Educators' Preparation to Teach, Perceived Teaching Presence, and Perceived Teaching Presence Behaviors in Blended and Online Learning Environments
Teaching in blended and online learning environments requires different pedagogical approaches than teaching in face-to-face learning environments. How educators are prepared to teach potentially impacts the quality of instruction provided in blended and online learning courses. Teaching presence is essential to achieving student learning outcomes, yet previous research has focused on student perceptions of teaching presence. Therefore, the purpose of this mixed methods convergent parallel study was to explore educators’ preparation to teach, perceived teaching presence, and perceived teaching presence behaviors in blended and online learning environments. The study was designed to examine the differences in educators’ perceived teaching presence and preparation to teach in blended and online learning environments. An adapted Community of Inquiry Survey Instrument was used to measure faculty perceptions of teaching presence. Results indicated a statistically significant difference between perceived teaching presence of facilitation for faculty that completed certification courses in preparation to teach in blended and online learning environments, as compared to faculty that only received on-the-job training. Qualitative responses to corresponding interview questions supported the findings. The findings of this study provide information to university educators and administrators supporting the importance of faculty preparation specific to teaching in blended and online learning environments.
Professional Behavior Attributes: A Survey of Occupational Therapy Faculty Perspectives
Professionalism in occupational therapy has been challenging to define due to differing values and behaviors across contexts and professions. There is a difference between how occupational therapy students and faculty view and comprehend professionalism suggesting that occupational therapists may not have an established sense of professionalism when entering the health care field for the first time. The study\u27s purpose was to examine occupational therapy faculty’s perceptions of essential professional behavior attributes that students should possess to succeed in occupational therapy practice. This study utilized a survey methodology to anonymously collect opinions from 150 occupational therapy faculty members across the United States regarding professional behavior attributes essential for entry-level occupational therapy education. Researchers found that the five most frequently observed professional behavior attributes in occupational therapy students were empathy, enthusiasm, being personable, having a positive attitude, and responsibility. The top seven most important professional behavior attributes were being clinically competent and ethical, having communication and interpersonal skills, and being adaptable, responsible, and empathetic. The results of this study indicate that occupational therapy faculty perceive that many vital attributes contribute to professionalism within the occupational therapy field and that teaching professionalism is an integral part of occupational therapy education. This study contributes to the current literature of defining professionalism within occupational therapy to better equip occupational therapy students entering into practice
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High-performance capillary electrophoresis of histones
A high performance capillary electrophoresis (HPCE) system has been developed for the fractionation of histones. This system involves electroinjection of the sample and electrophoresis in a 0.1M phosphate buffer at pH 2.5 in a 50 {mu}m {times} 35 cm coated capillary. Electrophoresis was accomplished in 9 minutes separating a whole histone preparation into its components in the following order of decreasing mobility; (MHP) H3, H1 (major variant), H1 (minor variant), (LHP) H3, (MHP) H2A (major variant), (LHP) H2A, H4, H2B, (MHP) H2A (minor variant) where MHP is the more hydrophobic component and LHP is the less hydrophobic component. This order of separation is very different from that found in acid-urea polyacrylamide gel electrophoresis and in reversed-phase HPLC and, thus, brings the histone biochemist a new dimension for the qualitative analysis of histone samples. 27 refs., 8 figs
Hepatotoxicity of a Cannabidiol-rich cannabis extract in the mouse model
© 2019 Xide Ye et al. Gastrodia elata Blume belongs to the Orchidaceae family. G. elata is often processed when used in traditional Chinese medicine (TCM). In the current study, a traditional processing method, known as Jianchang Bang, was applied. Steamed and dried (S&D) G. elata was processed with ginger juice for up to 5 days (GEP5D). An UHPLC-MS/MS combined with a chemometric method was developed for the analysis of processed G. elata along with the raw material as well as steamed and dried G. elata. As a result, the primary marker compounds were identified with the aid of TOF-MS and MS/MS analyses. Compared with the raw material of G. elata with GEP5D, three new parishin-type compounds were identified according to their retention time, accurate mass, and fragmentation patterns. The chromatographic peak areas for marker compounds, including S-(gastrodin)-glutathione, S-(4-hydroxybenzylamine)-glutathione, and parishin-type compounds, changed significantly. This result indicated that by applying the Jianchang Bang method, changes in chemical composition in G. elata contents were observed. The study also demonstrated that chemometric analysis is helpful in understanding the processing mechanism and will provide scientific support for the clinical application of G. elata
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Studies of alternative nuclear technologies
This report is a summary of tasks performed for the U.S. Arms Control and Disarmament Agency under Contract AC7NC114. The work is directly related to the Agency effort to examine potential alternative fuel cycles that might enhance uranium resource utilization, minimize plutonium production, and reduce the weapons proliferation risk from spent fuel reprocessing or early introduction of fast breeder reactors. Reported herein are summaries of various inter-related task assignments, including: fuel utilization in current light water reactors operating with the uranium fuel cycle; alternate fuel cycles, including the use of denatured fuel in LWRs and of the spectral shift concept for reactivity control; fuel utilization in high temperature graphite moderated reactors using the denatured fuel cycle; fuel utilization in heavy water reactors (CANDU type), including the use of enriched fuel, denatured fuel, and recycle of plutonium and U-233; the tandem fuel cycle (recovery of spent fuel and further irradiation in a CANDU type reactor); issues in the utilization of denatured fuel in LWRs; preliminary conceptual evaluation of a heavy water moderated reactor suitable for use in the United States
Risk Factors for Nipah Virus Encephalitis in Bangladesh1
Patients in Goalando were likely infected by direct contact with fruit bats or their secretions, rather than through contact with an intermediate host
Safety and molecular-toxicological implications of cannabidiol-rich cannabis extract and methylsulfonylmethane co-administration
© 2020 by the authors. Cannabidiol (CBD) is a biologically active, non-psychotropic component of Cannabis sativa whose popularity has grown exponentially in recent years. Besides a wealth of potential health benefits, ingestion of CBD poses risks for a number of side effects, of which hepatotoxicity and CBD/herb-drug interactions are of particular concern. Here, we investigated the interaction potential between the cannabidiol-rich cannabis extract (CRCE) and methylsulfonylmethane (MSM), a popular dietary supplement, in the mouse model. For this purpose, 8-week-old male C57BL6/J mice received MSM-containing water (80 mg/100 mL) ad libitum for 17 days. During the last three days of treatment, mice received three doses of CRCE administered in sesame oil via oral gavage (123 mg/kg/day). Administration of MSM alone did not result in any evidence of liver toxicity and did not induce expression of mouse cytochrome P450 (CYP) enzymes. Administration of CRCE did produce significant (p \u3c 0.05) increases in Cyp1a2, Cyp2b10, Cyp2c29, Cyp3a4, Cyp3a11, Cyp2c65, and Cyp2c66 messenger RNA, however, this effect was not amplified by MSM/CRCE cotreatment. Similarly, no evidence of liver toxicity was observed in MSM/CRCE dosed mice. In conclusion, short-term MSM/CRCE co-administration did not demonstrate any evidence of hepatotoxicity in the mouse model
More than words: The influence of affective content and linguistic style matches in online reviews on conversion rates
Customers increasingly rely on other consumers' reviews to make purchase decisions online. New insights into the customer review phenomenon can be derived from studying the semantic content and style properties of verbatim customer reviews to examine their influence on online retail sites' conversion rates. The authors employ text mining to extract changes in affective content and linguistic style properties of customer book reviews on Amazon.com. A dynamic panel data model reveals that the influence of positive affective content on conversion rates is asymmetrical, such that greater increases in positive affective content in customer reviews have a smaller effect on subsequent increases in conversion rate. No such tapering-off effect occurs for changes in negative affective content in reviews. Furthermore, positive changes in affective cues and increasing congruence with the product interest group's typical linguistic style directly and conjointly increase conversion rates. These findings suggest that managers should identify and promote the most influential reviews in a given product category, provide instructions to stimulate reviewers to write powerful reviews, and adapt the style of their own editorial reviews to the relevant product category
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