429 research outputs found

    The Null Decomposition of Conformal Algebras

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    We analyze the decomposition of the enveloping algebra of the conformal algebra in arbitrary dimension with respect to the mass-squared operator. It emerges that the subalgebra that commutes with the mass-squared is generated by its Poincare subalgebra together with a vector operator. The special cases of the conformal algebras of two and three dimensions are described in detail, including the construction of their Casimir operators.Comment: 31 page

    Direct and Indirect Effects of Child Abuse and Environmental Stress: A Lifecourse Perspective on Adversity and Depressive Symptoms

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    There is a great deal of evidence about the mental health implications of physical child abuse and environmental stressors, or hardships that people experience at the household and neighborhood level (e.g., neighborhood violence; economic hardship, substance abuse, or conflict among family members). Yet, studies often focus on either abuse or environmental stress, not both, or examine abuse and environmental stressors as a combined set of experiences. Less is known, therefore, about how child abuse and environmental stress might work as either distinct or interrelated risks to diminish mental health over time. In this longitudinal study, we used path analyses to examine the cumulative effects of physical child abuse and environmental stressors on adult depressive symptoms among a sample of children followed into adulthood (N = 356). The goal was to assess whether chronic physical child abuse remains an independent predictor of adult outcomes once we accounted for the cumulative effects of household and neighborhood stressors across the lifecourse. Cumulative measures of physical child abuse and environmental stress each independently predicted a higher likelihood of adult depressive symptoms (ß = .122, p \u3c .01 and ß = .283, p \u3c .001, respectively). After accounting for adolescent depressive symptoms, only cumulative environmental stressors independently predicted depressive symptoms (ß = .202, p \u3c .001). Tests of the indirect effect of cumulative environmental stress on the relationship between cumulative physical abuse and adult depressive symptoms were marginally statistically significant. Results add to literature that examines child abuse, adversity, and lifecourse perspectives on health. (PsycINFO Database Record (c) 2018 APA, all rights reserved

    Direct and Indirect Effects of Child Abuse and Environmental Stress: A Lifecourse Perspective on Adversity and Depressive Symptoms

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    There is a great deal of evidence about the mental health implications of physical child abuse and environmental stressors, or hardships that people experience at the household and neighborhood level (e.g., neighborhood violence; economic hardship, substance abuse, or conflict among family members). Yet, studies often focus on either abuse or environmental stress, not both, or examine abuse and environmental stressors as a combined set of experiences. Less is known, therefore, about how child abuse and environmental stress might work as either distinct or interrelated risks to diminish mental health over time. In this longitudinal study, we used path analyses to examine the cumulative effects of physical child abuse and environmental stressors on adult depressive symptoms among a sample of children followed into adulthood (N = 356). The goal was to assess whether chronic physical child abuse remains an independent predictor of adult outcomes once we accounted for the cumulative effects of household and neighborhood stressors across the lifecourse. Cumulative measures of physical child abuse and environmental stress each independently predicted a higher likelihood of adult depressive symptoms (ß = .122, p \u3c .01 and ß = .283, p \u3c .001, respectively). After accounting for adolescent depressive symptoms, only cumulative environmental stressors independently predicted depressive symptoms (ß = .202, p \u3c .001). Tests of the indirect effect of cumulative environmental stress on the relationship between cumulative physical abuse and adult depressive symptoms were marginally statistically significant. Results add to literature that examines child abuse, adversity, and lifecourse perspectives on health. (PsycINFO Database Record (c) 2018 APA, all rights reserved

    The Great Lakes Hydrography Dataset: Consistent, Binational Watersheds for the Laurentian Great Lakes Basin

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    Ecosystem‐based management of the Laurentian Great Lakes, which spans both the United States and Canada, is hampered by the lack of consistent binational watersheds for the entire Basin. Using comparable data sources and consistent methods, we developed spatially equivalent watershed boundaries for the binational extent of the Basin to create the Great Lakes Hydrography Dataset (GLHD). The GLHD consists of 5,589 watersheds for the entire Basin, covering a total area of approximately 547,967 km2, or about twice the 247,003 km2 surface water area of the Great Lakes. The GLHD improves upon existing watershed efforts by delineating watersheds for the entire Basin using consistent methods; enhancing the precision of watershed delineation using recently developed flow direction grids that have been hydrologically enforced and vetted by provincial and federal water resource agencies; and increasing the accuracy of watershed boundaries by enforcing embayments, delineating watersheds on islands, and delineating watersheds for all tributaries draining to connecting channels. In addition, the GLHD is packaged in a publically available geodatabase that includes synthetic stream networks, reach catchments, watershed boundaries, a broad set of attribute data for each tributary, and metadata documenting methodology. The GLHD provides a common set of watersheds and associated hydrography data for the Basin that will enhance binational efforts to protect and restore the Great Lakes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134077/1/jawr12435_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134077/2/jawr12435.pd

    An Electronic Analog of Synthetic Genetic Networks

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    An electronic analog of a synthetic genetic network known as the repressilator is proposed. The repressilator is a synthetic biological clock consisting of a cyclic inhibitory network of three negative regulatory genes which produces oscillations in the expressed protein concentrations. Compared to previous circuit analogs of the repressilator, the circuit here takes into account more accurately the kinetics of gene expression, inhibition, and protein degradation. A good agreement between circuit measurements and numerical prediction is observed. The circuit allows for easy control of the kinetic parameters thereby aiding investigations of large varieties of potential dynamics

    Creating Cartoons to Promote Leadership Skills and Explore Leadership Qualities

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    This document describes a strategy for increasing student leadership and creativity skills through the creation of cartoons. Creating cartoons engages students in divergent thinking and cognitive processes, such as perception, recall, and mental processing. When students create cartoons focused on a particular topic, they are making connections to their already developed schema by representing the idea or concept in a unique way. The cartoons presented in this report were created by an education professor, graduate students, preservice teachers, and third grade students. Many of the cartoons focus on the seven leadership skills articulated in Steven Covey’s “Leader in Me” program. These skills include be proactive; begin with the end in mind; put first things first; think win-win; seek first to understand, then to be understood; and synergize. The seventh leadership habit, which Covey calls sharpen the saw, promotes self-care and health. Supplementary leadership concepts are presented in additional cartoons with the following themes: active development of leadership skills, leaders are creative problem solvers, schools need to promote creativity and problem-solving, leaders should make good decisions, service learning promotes leadership, parents and communities can help, leaders need to be able to express themselves well, the vision of a leader, leaders care about others, persistence in the face of challenges, and confidence is a leadership trait. The Appendix contains 213 full-color leadership-themed cartoons, many of which employ humor, wordplay, and other creative strategies

    Olsalazine-Based Metal–Organic Frameworks as Biocompatible Platforms for H_2 Adsorption and Drug Delivery

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    The drug olsalazine (H_4olz) was employed as a ligand to synthesize a new series of mesoporous metal–organic frameworks that are expanded analogues of the well-known M_2(dobdc) materials (dobdc^4– = 2,5-dioxido-1,4-benzenedicarboxylate; M-MOF-74). The M_2(olz) frameworks (M = Mg, Fe, Co, Ni, and Zn) exhibit high surface areas with large hexagonal pore apertures that are approximately 27 Å in diameter. Variable temperature H_2 adsorption isotherms revealed strong adsorption at the open metal sites, and in situ infrared spectroscopy experiments on Mg_2(olz) and Ni_2(olz) were used to determine site-specific H_2 binding enthalpies. In addition to its capabilities for gas sorption, the highly biocompatible Mg_2(olz) framework was also evaluated as a platform for the delivery of olsalazine and other encapsulated therapeutics. The Mg_2(olz) material (86 wt % olsalazine) was shown to release the therapeutic linker through dissolution of the framework under simulated physiological conditions. Furthermore, Mg_2(olz) was used to encapsulate phenethylamine (PEA), a model drug for a broad class of bioactive compounds. Under simulated physiological conditions, Mg_2(olz)(PEA)_2 disassembled to release PEA from the pores and olsalazine from the framework itself, demonstrating that multiple therapeutic components can be delivered together at different rates. The low toxicity, high surface areas, and coordinatively unsaturated metal sites make these M_2(olz) materials promising for a range of potential applications, including drug delivery in the treatment of gastrointestinal diseases

    Olsalazine-Based Metal–Organic Frameworks as Biocompatible Platforms for H_2 Adsorption and Drug Delivery

    Get PDF
    The drug olsalazine (H_4olz) was employed as a ligand to synthesize a new series of mesoporous metal–organic frameworks that are expanded analogues of the well-known M_2(dobdc) materials (dobdc^4– = 2,5-dioxido-1,4-benzenedicarboxylate; M-MOF-74). The M_2(olz) frameworks (M = Mg, Fe, Co, Ni, and Zn) exhibit high surface areas with large hexagonal pore apertures that are approximately 27 Å in diameter. Variable temperature H_2 adsorption isotherms revealed strong adsorption at the open metal sites, and in situ infrared spectroscopy experiments on Mg_2(olz) and Ni_2(olz) were used to determine site-specific H_2 binding enthalpies. In addition to its capabilities for gas sorption, the highly biocompatible Mg_2(olz) framework was also evaluated as a platform for the delivery of olsalazine and other encapsulated therapeutics. The Mg_2(olz) material (86 wt % olsalazine) was shown to release the therapeutic linker through dissolution of the framework under simulated physiological conditions. Furthermore, Mg_2(olz) was used to encapsulate phenethylamine (PEA), a model drug for a broad class of bioactive compounds. Under simulated physiological conditions, Mg_2(olz)(PEA)_2 disassembled to release PEA from the pores and olsalazine from the framework itself, demonstrating that multiple therapeutic components can be delivered together at different rates. The low toxicity, high surface areas, and coordinatively unsaturated metal sites make these M_2(olz) materials promising for a range of potential applications, including drug delivery in the treatment of gastrointestinal diseases
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