1,397 research outputs found
Quantum fields, dark matter and non-standard Wigner classes
The Elko field of Ahluwalia and Grumiller is a quantum field for massive
spin-1/2 particles. It has been suggested as a candidate for dark matter. We
discuss our attempts to interpret the Elko field as a quantum field in the
sense of Weinberg. Our work suggests that one should investigate quantum fields
based on representations of the full Poincar\'e group which belong to one of
the non-standard Wigner classes.Comment: 6 pages. Submitted to proceedings of Dark2009, Christchurch, New
Zealand, January 200
Deformations of spacetime and internal symmetries
Algebraic deformations provide a systematic approach to generalizing the
symmetries of a physical theory through the introduction of new fundamental
constants. The applications of deformations of Lie algebras and Hopf algebras
to both spacetime and internal symmetries are discussed. As a specific example
we demonstrate how deforming the classical flavor group to the quantum
group (a Hopf algebra) and taking into account
electromagnetic mass splitting within isospin multiplets leads to new and
exceptionally accurate baryon mass sum rules that agree perfectly with
experimental data.Comment: 5th International Conference on New Frontiers in Physics, Crete,
Greece, July 6-14, 201
Seedling Emergence from Seed Banks in Ludwigia hexapetala-Invaded Wetlands: Implications for Restoration
Soil seed banks play a critical role in the maintenance of wetland plant communities and contribute to revegetation following disturbances. Analysis of the seed bank can therefore inform restoration planning and management. Emergence from seed banks may vary in response to hydrologic conditions and sediment disturbances. To assess the community-level impact of exotic Ludwigia hexapetala on soil seed banks, we compared differences in species composition of standing vegetation among invaded and non-invaded wetlands and the degree of similarity between vegetation and soil seed banks in northern California. To determine potential seed bank recruitment of L. hexapetala and associated plant species, we conducted a seedling emergence assay in response to inundation regime (drawdown vs. flooded) and sediment depth (surface vs. buried). Plant species richness, evenness, and Shannon’s H’ diversity were substantially lower in standing vegetation at L. hexapetala invaded sites as compared to non-invaded sites. Over 12 months, 69 plant taxa germinated from the seed banks, including L. hexapetala and several other exotic taxa. Seedling density varied among sites, being the highest (10,500 seedlings m−2) in surface sediments from non-invaded sites subjected to drawdown treatments. These results signal the need for invasive plant management strategies to deplete undesirable seed banks for restoration success
Medical Specialty Camp Alumni Perceptions of Outcomes and Experiences
Summertime can be an important time of year for youth development. During summer, children and youth can experience belonging, develop meaningful relationships, and engage in interest-driven learning (NASEM, 2019). For example, Richmond et al. (2019) found that camp, home, work, school, sports, and church contributed to important and useful skills and traits for youth. Specifically, they found that camp was a primary learning setting for developing affinity for nature, how to live with peers, leisure skills, a willingness to try new things, independence, being present, and empathy and compassion whereas school and home were primary learning settings for other outcomes such as appreciation for differences, perseverance, leadership, and emotion regulation. Warner and Sibthorp (2022) shared similar findings where camp was one of several enriching options for youth during summertime and recommended that camp professionals consider how camp programming fits within the broader landscape of summertime activities including vacation, home, arts, and summer school
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Association between domains of quality of life and patients with klinefelter syndrome: a systematic review.
Klinefelter syndrome (KS) is the second-most prevalent chromosomal disorder in men, though late diagnosis is very common and 50-75% of men remain undiagnosed. Evidence suggests that men with KS have impaired Quality of Life (QoL) but research on how the diagnosis of KS is associated with different QoL domains and what factors influence patients' QoL is limited. This study aimed to provide a systematic review of the published evidence on factors that influence QoL in men with KS. DESIGN: Systematic review and meta-analysis with narrative synthesis. METHODS: Medline, Cochrane, Embase, Psychinfo, CINAHL, BASE and relevant publication reference lists were searched in January 2021. Eligible studies included RCTs, cohort studies, cross-sectional studies and epidemiology studies on KS and its effect on QoL and all domains of WHOQOL-100. Clinical studies with no date restriction published in English were included. RESULTS: Thematic analysis was completed on thirteen studies, with a meta-analysis of intelligence quotient (IQ) completed on seven studies. Twelve out of 13 studies suggested that KS negatively affected QoL outcomes and KS was associated with impairments in physical, psychological, level independence and social relationship domains of WHOQOL-100. Meta-analysis suggested men with KS have significantly lower full-scale Intelligence Quotient versus controls (P <0.00001). CONCLUSIONS: This is the first evidence synthesis of QoL in men with KS. Current evidence suggests that combined physical and psychological impairments affect men with KS who also experience impairments in relationships and independence in society. Further research is needed to identify factors that influence QoL in men with KS
HKT Geometry and Fake Five Dimensional Supergravity
Recent results on the relation between hyper-Kahler geometry with torsion and
solutions admitting Killing spinors in minimal de sitter supergravity are
extended to more general supergravity models with vector multiplets.Comment: 14 pages, latex. Minor typos corrected, references adde
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