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Rockville, MD, United States

Parris G.E.,Montgomery College
Dose-Response | Year: 2015

This manuscript proposes a hypothesis to explain the U-shaped dose-response observed for angiostatin and other high-molecular-weight drugs in various anti-cancer bio-assays. The dose-response curves for angiostatin and endostatin (measured as suppression of tumor growth) go through an optimum (i.e., minimum tumor growth) and then becomes less effective at higher doses. The literature suggests that at lower doses the primary action of these high-molecular-weight drugs is to counteract the angiogenic effects of vascular endothelial growth factor (VEGF). To do this, the drugs must pass out of the blood vessel and enter the extra-cellular matrix (ECM) where VEGF induces the growth and fusion of tip cells. Ironically, VEGF actually facilitates access of the drugs to the ECM by making the vascular endothelium leaky. At higher doses, the high-molecular-weight drugs seem to reverse VEGF-induced permeability of the endothelium. Thus, at high dose rates, it is hypothesized that the drugs are not able to enter the ECM and block the angiogenic effects of VEGF there. As a result, high doses of the drugs do not suppress vascularization of the tumor or tumor growth. Moreover, if the permeability of the vessels is suppressed, the VEGF released by the stroma is concentrated in the ECM where it amplifies the angiogenic activity around the tumor. © The Author(s) 2015.

Li Z.,Institute for Bioscience and Biotechnology Research | Kelman L.M.,Montgomery College | Kelman Z.,Institute for Bioscience and Biotechnology Research | Kelman Z.,U.S. National Institute of Standards and Technology
Biochemical Society Transactions | Year: 2013

DNA replication plays an essential role in all life forms. Research on archaeal DNA replication began approximately 20 years ago. Progress was hindered, however, by the lack of genetic tools to supplement the biochemical and structural studies. This has changed, however, and genetic approaches are now available for several archaeal species. One of these organisms is the thermophilic euryarchaeon Thermococcus kodakarensis. In the present paper, the recent developments in the biochemical, structural and genetic studies on the replication machinery of T. kodakarensis are summarized. © 2013 Biochemical Society.

Eliasson A.H.,Montgomery College | Eliasson A.H.,U.S. Army | Lettieri C.J.,U.S. Army
Sleep and Breathing | Year: 2010

Purpose: Prior studies have placed emphasis on the need for adequate total sleep time for student performance. We sought to investigate the relative importance of total sleep time compared to the timing of sleep and wakefulness for academic performance. Methods: We performed a questionnaire-based survey of college students in October 2007. The questionnaire gathered detailed information on sleep habits including naps, reasons for missing sleep, academic performance, study habits, time spent working outside of school, and stimulant use. Results: Compared to those with the lowest academic performance, students with the highest performance had significantly earlier bedtimes (p=0.05) and wake times (p=0.008). Napping tended to be more common among high performers (p=0.07). Of importance, there were no significant differences in total sleep time with or without naps, weekend sleep habits, study time, gender, race, reasons for staying up at night, nor in use of caffeinated beverages, over-the-counter stimulant pills, or use of prescription stimulants. Conclusions: Timing of sleep and wakefulness correlated more closely with academic performance than total sleep time and other relevant factors. These findings have important implications for programs intended to improve academic performance by targeting sleep habits of students. © 2009 US Government.

Yoon Y.-H.,DATA Incorporated | Yi H.-Y.,DATA Incorporated | Thomson P.C.,Montgomery College
Alcoholism: Clinical and Experimental Research | Year: 2011

Background: Hispanics have much higher cirrhosis mortality rates than non-Hispanic Blacks and Whites. Although heavy alcohol use and hepatitis C virus (HCV) infection are two major risk factors for cirrhosis, no studies have systematically assessed the contribution of alcohol- and HCV-related cirrhosis deaths to the total cirrhosis mortality for Hispanics as a whole and its variations across Hispanic subgroups. To fill this gap, this study presents the latest data on total cirrhosis mortality as well as its component alcohol- and HCV-related cirrhosis mortality for all Hispanics and for Hispanic subgroups. Methods: The multiple-cause approach was used to analyze data from the U.S. Multiple Cause of Death Data Files for 28,432 Hispanics and 168,856 non-Hispanic Whites (as a comparison group) who died from cirrhosis as the underlying or a contributing cause during 2000-2004. Four major Hispanic subgroups were defined by national origin or ancestry, including Mexicans, Puerto Ricans, Cubans, and Other Hispanics. The cirrhosis deaths were divided into four distinctive cause-of-death categories: alcohol-related, HCV-related, both alcohol- and HCV-related, and neither alcohol- nor HCV-related. Age-adjusted total cirrhosis death rates and percentage shares of the cause-specific categories were compared across Hispanic subgroups and non-Hispanic Whites. Results: Compared with non-Hispanic Whites, all Hispanic subgroups except Cubans had much higher cirrhosis mortality. The age-adjusted total cirrhosis death rates were twice as high for Puerto Ricans and Mexicans as for non-Hispanic Whites. Alcohol-related and HCV-related cirrhosis death rates also were higher for most Hispanic subgroups than for non-Hispanic Whites. Conclusions: Heavy alcohol use and hepatitis C viral infection are two important factors contributing to the high cirrhosis mortality among Hispanics. However, their relative contributions to total cirrhosis mortality varied by gender and Hispanic subgroup. This information is useful for targeted prevention and intervention efforts to address the excessive cirrhosis mortality in the Hispanic population. © 2010 by the Research Society on Alcoholism. No claim to original U.S. government works.

Agency: NSF | Branch: Standard Grant | Program: | Phase: ROBERT NOYCE SCHOLARSHIP PGM | Award Amount: 1.18M | Year: 2016

The goal of this Noyce Teacher Scholarship and Stipend project is to increase the pool of highly qualified STEM teachers in central Maryland. Faculty from Montgomery Colleges STEM divisions as well as the School of Education will work with Montgomery County Public Schools to support two strands of development: the first will include the recruitment and support of 39 STEM professionals as they transition into STEM teaching positions, the second will expand outreach to encourage undergraduate STEM majors to transfer to STEM teacher preparation programs at regional four-year institutions. The alternative teacher preparation program for career changers involves intensive pre-service training and a teaching internship flowed by a year-long residency. The project will integrate a variety of elements to address challenges faced by students enrolled in this rigorous course of study, including (a) orientation materials that address the time commitment, (b) increased assessment and feedback to students designed to bolster their self-efficacy and personal confidence, and (c) assignment to field placements with peer partners.

The key aspects of the project are designed to respond to an analysis of barriers for transfer students enrollment in STEM majors after leaving Montgomery College and the retention of career changers in their alternative teacher preparation program, which was supported by a Noyce Capacity Building award. For community college transfers, a comprehensive plan has been designed to align coursework between Montgomery College and regional 4-year institutions; a strategy meant to strengthen the pool of STEM majors who will be attracted to teaching. For the scholarship recipients (career changers) everything from the selection process, during which applicants will be pre-screened using results of the Haberman Star Teacher Pre-Screener Assessment to determine if their mindsets are compatible with teaching in high-needs schools, to the training activities are designed to graduate STEM teachers who are both confident and resilient. Formative and summative evaluation will include the results of assessment of the surveys of program participants, internship supervisors, and mentor teachers and principals as well as teacher performance during the resident year. Surveys and interviews will also be used to assess self-efficacy of the participants and to identify their best-perceived supports. Program activities and outcomes will be disseminated through the meetings of the National Association of Community College Teacher Education Programs and the National Center for Education Information, among others. Manuscripts will be submitted to the Journal of STEM Education and the Journal of the National Association for Alternative Certification.

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