2,484 research outputs found
Nuclear Astrophysics in Storage Rings
Nuclear reaction cross sections are usually very small in typical
astrophysical environments. It has been one of the major challenges of
experimental nuclear astrophysics to assess the magnitude of these cross
sections in the laboratory. For a successful experiment high luminosity beams
are needed. Increasing the target width, one also increases the reaction
yields. But, this is of limited use due to multiple scattering in the target.
Storage rings are a very good way to overcome these difficulties. In principle,
they can be tuned to large luminosities, and have the advantage of crossing the
interaction region many times per second (typically one million/s),
compensating low density internal gas targets, or low reaction rates in
beam-beam collisions. Storage rings are also ideal tools for precise
measurements of masses and beta-decay lifetimes of nuclei of relevance for
astrophysics.Comment: 14 pages, LaTeX, figures available upon reques
Understanding the Internal Forces on Post Operation Implants Using the Hip Joint Motion Simulator
In the United States, 18 of every 100 patients that receive hip replacement surgery need a secondary procedure due to implant wear or total hip displacement. This number remains high due to the lack of a good way for doctors to fully understand what is happening to their patient\u27s prosthetics during their lives after surgery. Our machine will fill this need as a more reliable source of data collection for the forces acting on a hip implant after surgery. The hip joint simulator will apply cyclical loading and motion profiles that can mimic the actions of walking, jogging, and running providing a clear picture of the effects of everyday life on a prosthetic. The team\u27s focus will be on developing and testing the simulation machine while the sponsor of the project will take the final prototype and implement an energy harvesting device of his own design into the loading apparatus of the simulator. This device will be used to understand the relationship between the loading applied by the machine and the electrical output the loading can produce. The team expects to gather the loading and motion data for multiple gait cycles and produce graphs depicting the forces and moments acting on an actual hip implant. Supplying a more complete understanding of the day-to-day life of a hip replacement patient post-op. This data will be used to prove the design\u27s use and functionality while also providing greater insight into the biomechanical understanding of the hip joint
Effectiveness of a Faculty Development Program in Fostering Interprofessional Education Competencies
AbstractBackground: To determine the effectiveness of a faculty development program offered to clinical faculty in fostering interprofessional education competencies.Methods and Findings: A pre-post randomized control group design was used in which only one of two cohorts of clinical faculty received an interprofessional educational intervention. Both cohorts then facilitated case-based interprofessional education sessions for student learners. A variety of outcome measures were used to assess differences between groups in terms of knowledge, skills, and attitudes related to interprofessional education and practice. No significant differences were noted between the control and intervention groups.Conclusions: The use of a pre-post randomized control group design to measure effectiveness of an educational intervention should be considered to demonstrate the impact of educational interventions
Frizzled-7 is required for Wnt signaling in gastric tumours with and without Apc mutations
A subset of patients with gastric cancer have mutations in genes that participate in or regulate Wnt signaling at the level of ligand (Wnt) receptor (Fzd) binding. Moreover, increased Fzd expression is associated with poor clinical outcome. Despite these findings, there are no in vivo studies investigating the potential of targeting Wnt receptors for treating gastric cancer, and the specific Wnt receptor transmitting oncogenic Wnt signaling in gastric cancer is unknown. Here, we use inhibitors of Wnt/Fzd (OMP-18R5/vantictumab) and conditional gene deletion to test the therapeutic potential of targeting Wnt signaling in preclinical models of intestinal-type gastric cancer and ex vivo organoid cultures. Pharmacologic targeting of Fzd inhibited the growth of gastric adenomas in vivo. We identified Fzd7 to be the predominant Wnt receptor responsible for transmitting Wnt signaling in human gastric cancer cells and mouse models of gastric cancer, whereby Fzd7-deficient cells were retained in gastric adenomas but were unable to respond to Wnt signals and consequently failed to proliferate. Genetic deletion of Fzd7 or treatment with vantictumab was sufficient to inhibit the growth of gastric adenomas with or without mutations to Apc. Vantictumab is currently in phase Ib clinical trials for advanced pancreatic, lung, and breast cancer. Our data extend the scope of patients that may benefit from this therapeutic approach as we demonstrate that this drug will be effective in treating patients with gastric cancer regardless of APC mutation status
Concert recording 2019-04-01
[Track 1]. Glory to God -- [Track 2]. Morning tide -- [Track 3]. Name -- [Track 4]. Light from below -- [Track 5]. Demented dances. I. Erratic polka II. Waltz in limbo III. Grandiose gigue
S17(0) Determined from the Coulomb Breakup of 83 MeV/nucleon 8B
A kinematically complete measurement was made of the Coulomb dissociation of
8B nuclei on a Pb target at 83 MeV/nucleon. The cross section was measured at
low relative energies in order to infer the astrophysical S factor for the
7Be(p,gamma)8B reaction. A first-order perturbation theory analysis of the
reaction dynamics including E1, E2, and M1 transitions was employed to extract
the E1 strength relevant to neutrino-producing reactions in the solar interior.
By fitting the measured cross section from Erel = 130 keV to 400 keV, we find
S17(0) = 17.8 (+1.4, -1.2) eV b
Standard Neutrino Spectrum from B-8 Decay
We present a systematic evaluation of the shape of the neutrino energy
spectrum produced by beta-decay of B. We place special emphasis on
determining the range of uncertainties permitted by existing laboratory data
and theoretical ingredients (such as forbidden and radiative corrections). We
review and compare the available experimental data on the
BBe decay chain. We analyze the theoretical and
experimental uncertainties quantitatively. We give a numerical representation
of the best-fit (standard-model) neutrino spectrum, as well as two extreme
deviations from the standard spectrum that represent the total (experimental
and theoretical) effective deviations. Solar neutrino experiments
that are currently being developed will be able to measure the shape of the
B neutrino spectrum above about 5 MeV. An observed distortion of the B
solar neutrino spectrum outside the range given in the present work could be
considered as evidence, at an effective significance level greater than three
standard deviations, for physics beyond the standard electroweak model. We use
the most recent available experimental data on the Gamow--Teller strengths in
the system to calculate the B neutrino absorption cross section on
chlorine: ~cm (
errors). The chlorine cross section is also given as a function of the neutrino
energy. The B neutrino absorption cross section in gallium is cm ( errors).Comment: Revised version, to appear in Phys. Rev.
The medical student
The Medical Student was published from 1888-1921 by the students of Boston University School of Medicine
- âŠ