243 research outputs found
Testing Modified Dark Matter with Galaxy Clusters: Does Dark Matter know about the Cosmological Constant?
We discuss the possibility that the cold dark matter mass profiles contain
information on the cosmological constant, and that such information constrains
the nature of cold dark matter (CDM). We call this approach Modified Dark
Matter (MDM). In particular, we examine the ability of MDM to explain the
observed mass profiles of 13 galaxy clusters. Using general arguments from
gravitational thermodynamics, we provide a theoretical justification for our
MDM mass profile and successfully compare it to the NFW mass profiles both on
cluster and galactic scales. Our results suggest that indeed the CDM mass
profiles contain information about the cosmological constant in a non-trivial
way
Testing MONDian Dark Matter with Galactic Rotation Curves
MONDian dark matter (MDM) is a new form of dark matter quantum that naturally
accounts for Milgrom's scaling, usually associated with modified Newtonian
dynamics (MOND), and theoretically behaves like cold dark matter (CDM) at
cluster and cosmic scales. In this paper, we provide the first observational
test of MDM by fitting rotation curves to a sample of 30 local spiral galaxies
(z approximately 0.003). For comparison, we also fit the galactic rotation
curves using MOND, and CDM. We find that all three models fit the data well.
The rotation curves predicted by MDM and MOND are virtually indistinguishable
over the range of observed radii (~1 to 30 kpc). The best-fit MDM and CDM
density profiles are compared. We also compare with MDM the dark matter density
profiles arising from MOND if Milgrom's formula is interpreted as Newtonian
gravity with an extra source term instead of as a modification of inertia. We
find that discrepancies between MDM and MOND will occur near the center of a
typical spiral galaxy. In these regions, instead of continuing to rise sharply,
the MDM mass density turns over and drops as we approach the center of the
galaxy. Our results show that MDM, which restricts the nature of the dark
matter quantum by accounting for Milgrom's scaling, accurately reproduces
observed rotation curves.Comment: Preprint number IPMU13-0147. Accepted for publication in Ap
Zero temperature string breaking in lattice quantum chromodynamics
The separation of a heavy quark and antiquark pair leads to the formation of
a tube of flux, or "string", which should break in the presence of light
quark-antiquark pairs. This expected zero-temperature phenomenon has proven
elusive in simulations of lattice QCD. We study mixing between the string state
and the two-meson decay channel in QCD with two flavors of dynamical sea
quarks. We confirm that mixing is weak and find that it decreases at level
crossing. While our study does not show direct effects of internal quark loops,
our results, combined with unitarity, give clear confirmation of string
breaking.Comment: 20 pages, 7 figures. With small clarifications and two additions to
references. Submitted to Phys. Rev.
A regionally resolved inventory of High Mountain Asia surge-type glaciers, derived from a multi-factor remote sensing approach
This study was supported by the Strategic Priority Research Programs of the Chinese Academy of Sciences (grant nos. XDA20100300 and XDA19070202) and the Swiss National Science Foundation (200021E_177652/1) within the framework of the DFG Research Unit GlobalCDA (FOR2630).Knowledge about the occurrence and characteristics of surge-type glaciers is crucial due to the impact of surging on glacier melt and glacier-related hazards. One of the super-clusters of surge-type glaciers is High Mountain Asia (HMA). However, no consistent region-wide inventory of surge-type glaciers in HMA exists. We present a regionally resolved inventory of surge-type glaciers based on their behaviour across High Mountain Asia between 2000 and 2018. We identify surge-type behaviour from surface velocity, elevation and feature change patterns using a multi-factor remote sensing approach that combines yearly ITS_LIVE velocity data, DEM differences and very-high-resolution imagery (Bing Maps, Google Earth). Out of the ≈95000 glaciers in HMA, we identified 666 that show diagnostic surge-type glacier behaviour between 2000 and 2018, which are mainly found in the Karakoram (223) and the Pamir regions (223). The total area covered by the 666 surge-type glaciers represents 19.5% of the glacierized area in Randolph Glacier Inventory (RGI) V6.0 polygons in HMA. Only 68 glaciers were already identified as "surge type" in the RGI V6.0. We further validate 107 glaciers previously labelled as "probably surge type" and newly identify 491 glaciers, not previously reported in other inventories covering HMA. We finally discuss the possibility of self-organized criticality in glacier surges. Across all regions of HMA, the surge-affected area within glacier complexes displays a significant power law dependency with glacier length.Publisher PDFPeer reviewe
Ecological Impacts of the Space Shuttle Program at John F. Kennedy Space Center, Florida
The Space Shuttle Program was one of NASAs first major undertakings to fall under the environmental impact analysis and documentation requirements of the National Environmental Policy Act of 1969 (NEPA). Space Shuttle Program activities at John F. Kennedy Space Center (KSC) and the associated Merritt Island National Wildlife Refuge (MINWR) contributed directly and indirectly to both negative and positive ecological trends in the region through the long-term, stable expenditure of resources over the 40 year program life cycle. These expenditures provided support to regional growth and development in conjunction with other sources that altered land use patterns, eliminated and modified habitats, and contributed to cultural eutrophication of the Indian River Lagoon. At KSC, most Space Shuttle Program related actions were conducted in previously developed facilities and industrial areas with the exception of the construction of the shuttle landing facility (SLF) and the space station processing facility (SSPF). Launch and operations impacts were minimal as a result of the low annual launch rate. The majority of concerns identified during the NEPA process such as potential weather modification, acid rain off site, and local climate change did not occur. Launch impacts from deposition of HCl and particulates were assimilated as a result of the high buffering capacity of the system and low launch and loading rates. Metals deposition from exhaust deposition did not display acute impacts. Sub-lethal effects are being investigated as part of the Resource Conservation and Recovery Act (RCRA) regulatory process. Major positive Space Shuttle Program effects were derived from the adequate resources available at the Center to implement the numerous environmental laws and regulations designed to enhance the quality of the environment and minimize impacts from human activities. This included reduced discharges of domestic and industrial wastewater, creation of stormwater management systems, remediation of past contamination sites, implementation of hazardous waste management systems, and creation of a culture of sustainability. Working with partners such as the USFWS and the St Johns River Water Management District (SJRWMD), wetlands and scrub restoration and management initiatives were implemented to enhance fish and wildlife populations at the Center. KSC remains the single largest preserve on the east coast of Florida in part due to NASAs commitment to stewardship. Ongoing Ecological Program projects are directed at development of information and knowledge to address future KSC management questions including the transition to a joint government and commercial launch facility, enhanced habitat management requirements for wetlands and scrub, potential impacts of emerging contaminants, and adaptation to climate change including projected sea level rise over the next 50-75 years
Supporting Learning and Teaching in Primary Education
The book is aimed at all those studying on Foundation Degrees in supporting primary and early years teaching and learning, and particularly those working at levels 4 and 5. It is written in an accessible style with a focus on work-based professional development and encourages critical reflection throughout. It starts with a discussion of reflective practice, and includes helpful guidance on developing effective study skills. Each chapter then focuses on a key topic in education, learning and development, considers any relevant policies and legislation, examines educational theories in relation to professional practice and provides concise case studies to contextualise the learning. It provides up-to-date and relevant material on supporting the new national curriculum, safeguarding, SEN and inclusion issues, and schools as organisations. It also covers the competencies for Higher Level Teaching Assistants
Global Oncology Research and Training Collaborations Led by the National Cancer Institute (NCI)–Designated Cancer Centers: Results From the 2018 NCI/ASCO Global Oncology Survey of NCI-Designated Cancer Centers
PURPOSE:
The National Cancer Institute (NCI)–Designated Cancer Centers (NDCCs) are active in global oncology research and training, leading collaborations that contribute to the evidence to support global cancer control. To better understand global oncology activities led by NDCCs, the National Cancer Institute Center for Global Health (NCI-CGH) collaborated with ASCO to conduct the 2018 NCI/ASCO Global Oncology Survey of NDCCs.
METHODS:
The 70 NDCCs received a two-part survey that focused on global oncology programs at NDCCs and non–National Institutes of Health (NIH)–funded global oncology projects with an international collaborator led by the NDCCs. Sixty-five NDCCs responded to the survey, and 57 reported non–NIH-funded global oncology projects. Data were cleaned, coded, and analyzed by NCI-CGH staff.
RESULTS:
Thirty NDCCs (43%) report having a global oncology program, and 538 non–NIH-funded global oncology projects were reported. Of the NDCCs with global oncology programs, 17 report that trainees complete rotations outside the United States, and the same number enroll trainees from low- and middle-income countries (LMICs). In addition, 147 (28%) of the non–NIH-funded projects focused on capacity building or training, the second highest category after research. Of the 30 top project collaborator countries, 17 were LMICs. Compared with the NCI-funded international grant portfolio, non–NIH-funded global oncology projects were more likely to focus on prevention (12% NCI-funded v 20% non–NIH-funded); early detection, diagnosis, and prognosis (23% v 30%); and cancer control, survivorship, and outcomes research (13% v 22%).
CONCLUSION:
This survey shows that there is a substantial amount of global oncology research and training supported by NDCCs, and much of this is happening in LMICs. Results of the 2018 Global Oncology Survey can be used to foster opportunities for NDCCs to work collaboratively on activities and to share their findings with relevant stakeholders in their LMIC collaborator countries
Landscape of Global Oncology Research and Training at National Cancer Institute-Designated Cancer Centers: Results of the 2018 to 2019 Global Oncology Survey.
PURPOSE: The National Cancer Institute (NCI)-Designated Cancer Centers (NDCCs) are active in global oncology research and training, leading collaborations to support global cancer control. To better understand global oncology activities led by NDCCs, the NCI Center for Global Health collaborated with ASCO to conduct the 2018/2019 NCI/ASCO Global Oncology Survey of NDCCs. METHODS: Seventy NDCCs received a two-part survey that focused on global oncology programs at NDCCs and non-National Institutes of Health (NIH)-funded global oncology projects with an international collaborator led by the NDCCs. Sixty-seven NDCCs responded to the survey. Data were coded and analyzed by NCI-Center for Global Health staff. RESULTS: Thirty-three NDCCs (47%) reported having a global oncology program, and 61 (87%) reported a collective total of 613 non-NIH-funded global oncology projects. Of the NDCCs with global oncology programs, 17 reported that trainees completed rotations outside the United States and the same number enrolled trainees from low- and middle-income countries (LMIC). Primary focus areas of non-NIH-funded projects were research (469 [76.5%]) and capacity building or training (197 [32.1%]). Projects included collaborators from 110 countries; 68 of these were LMIC. CONCLUSION: This survey shows that there is a substantial amount of global oncology research and training conducted by NDCCs and that much of this is happening in LMIC. Trends in these data reflect those in recent literature: The field of global oncology is growing, advancing scientific knowledge, contributing to building research and training capacity in LMIC, and becoming a recognized career path. Results of the 2018 Global Oncology Survey can be used to foster opportunities for NDCCs to work collaboratively on activities and to share their findings with relevant stakeholders in their LMIC collaborator countries
Exile Vol. I No. 1
SHORT STORIES
Louie, the Cab Driver by Lynn Herrick 5
Anna Dietrich by Jane Erb 13
Ground-Level Appointment by Keith Opdahl 15
Conveyor Belt by George Mahon 30
ESSAYS
The Examined Life Re-Examined by Doug James 10
Concerning Flem Snopes and Benjamin Franklin by David Schieber 24
Who Fathered the Footnote? by Diane Hostetler 28
POETRY
Carousel by Sally Falch 12
March and Yesterday by Midge Greenlee 23
Amusement Muse by John Miller 27
North Watch by John Hodges 27
Pursuit by James Bowman 32
Three Poems by Jean Duncan:
Venice 33
Innsbruck 34
Darmstadt 3
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