66 research outputs found
Vector dark matter in supercooled Higgs portal models
We consider extensions of the Standard Model by a hidden sector consisting of
a gauge field coupled with a scalar field. Assuming the absence of dimensionful
parameters in the tree level potential, radiative symmetry breaking will make
the hidden sector gauge field massive and induce the electroweak scale of the
Standard Model. We consider separately dark sector gauge groups
and , and focus on probing the models with a combination of
direct detection experiments and gravitational wave observatories. We find that
recent dark matter direct detection results significantly constrain the
parameter space of the models where they can account for the observed dark
matter relic density via freeze-out. The gravitational wave signals originating
from strongly first order electroweak phase transition in these models can be
probed in future gravitational wave observatories such as LISA. We show how the
projected results compliment direct detection experiments and can help probe
parameter space near the neutrino floor of direct detection.Comment: 18 pages, 5 figure
The Arctic in the twenty-first century: changing biogeochemical linkages across a paraglacial landscape of Greenland
The Kangerlussuaq area of southwest Greenland encompasses diverse ecological, geomorphic, and climate gradients that function over a range of spatial and temporal scales. Ecosystems range from the microbial communities on the ice sheet and moisture-stressed terrestrial vegetation (and their associated herbivores) to freshwater and oligosaline lakes. These ecosystems are linked by a dynamic glacio-fluvial-aeolian geomorphic system that transports water, geological material, organic carbon and nutrients from the glacier surface to adjacent terrestrial and aquatic systems. This paraglacial system is now subject to substantial change because of rapid regional warming since 2000. Here, we describe changes in the eco- and geomorphic systems at a range of timescales and explore rapid future change in the links that integrate these systems. We highlight the importance of cross-system subsidies at the landscape scale and, importantly, how these might change in the near future as the Arctic is expected to continue to warm
PO-0875: Patient specific scatter distributions in CBCT imaging calculated by Monte Carlo simulations
This paper proposes a hybrid software-hardware high-resolution projection system for 3D imaging based on fringe projection. The proposed solution combines the advantages of a digital projection with those of an analogue one. It is programmable and allows a high projection rate by avoiding mechanical displacements in the projection system. Moreover, it does not suffer from the limitations of digital systems such as the presence of inter-pixel gaps and limited resolution. The proposed projection system is relatively inexpensive to build since it is composed of a simple arrangement off-the-shelf components. The system is a combination of a low-resolution digital device such as a DMD, LCoS or LCD, some optical components and software to generate the fringe patterns. A prototype of a 3D scanner based on the proposed projection system is used to asses the fitness of the proposed technology.Peer reviewed: YesNRC publication: Ye
PO-0875: Patient specific scatter distributions in CBCT imaging calculated by Monte Carlo simulations
Evidence of a Monoclonal Origin for Bilateral Serous Tubal Intraepithelial Neoplasia.
Serous tubal intraepithelial carcinoma (STIC) is found in 10% to 60% of cases of tuboovarian high-grade serous carcinoma (HGSC) and is presumed to be the site of origin, linking many HGSCs to the fallopian tube. Bilateral STIC is present in ∼20% of cases. Because clonal Tp53 mutations are a defining feature of HGSC, including their associated STICs, we analyzed 4 cases of bilateral serous tubal intraepithelial neoplasia (STIN), including STIC and Tp53-mutated serous tubal intraepithelial lesions (STILs), associated with HGSC to determine whether they contained the same or different p53 mutations. Extracted DNA from STINs, concurrent HGSCs and control tissues was analyzed for mutations in all exons of Tp53. Sequencing was successful in 3 of the 4 cases, and an identical Tp53 mutation was detected in the HGSC and bilateral STINs in 2 of these 3 cases. One STIN was morphologically a STIL. These findings confirm that a subset of bilateral STINs share the same Tp53 mutation, implying that at least one of the STINs is an intraepithelial metastasis from either the contralateral STIN or HGSC. This study complements others addressing the multiple origins of STIN in the setting of existing HGSC. It further underscores the fact that potential overlap in biologic behavior between STILs and STICs as well as timing and direction of metastatic spread has yet to be resolved
Regional variation in green-up timing along a caribou migratory corridor: Spatial associations with snowmelt and temperature
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