5 research outputs found
Improving the Performance of Cryogenic Calorimeters with Nonlinear Multivariate Noise Cancellation Algorithms
State-of-the-art physics experiments require high-resolution, low-noise, and
low-threshold detectors to achieve competitive scientific results. However,
experimental environments invariably introduce sources of noise, such as
electrical interference or microphonics. The sources of this environmental
noise can often be monitored by adding specially designed "auxiliary devices"
(e.g. microphones, accelerometers, seismometers, magnetometers, and antennae).
A model can then be constructed to predict the detector noise based on the
auxiliary device information, which can then be subtracted from the true
detector signal. Here, we present a multivariate noise cancellation algorithm
which can be used in a variety of settings to improve the performance of
detectors using multiple auxiliary devices. To validate this approach, we apply
it to simulated data to remove noise due to electromagnetic interference and
microphonic vibrations. We then employ the algorithm to a cryogenic light
detector in the laboratory and show an improvement in the detector performance.
Finally, we motivate the use of nonlinear terms to better model vibrational
contributions to the noise in thermal detectors. We show a further improvement
in the performance of a particular channel of the CUORE detector when using the
nonlinear algorithm in combination with optimal filtering techniques.Comment: 21 pages, 15 figures, 7 table
Demonstration of surface electron rejection with interleaved germanium detectors for dark matter searches
The following article appeared in Applied Physics Letters 103.16 (2013): 164105 and may be found at http://scitation.aip.org/content/aip/journal/apl/100/26/10.1063/1.4729825The SuperCDMS experiment in the Soudan Underground Laboratory searches for dark matter with a 9-kg array of cryogenic germanium detectors. Symmetric sensors on opposite sides measure both charge and phonons from each particle interaction, providing excellent discrimination between electron and nuclear recoils, and between surface and interior events. Surface event rejection capabilities were tested with two 210 Pb sources producing âŒ130 beta decays/hr. In âŒ800 live hours, no events leaked into the 8â115âkeV signal region, giving upper limit leakage fraction 1.7âĂâ10â5 at 90% C.L., corresponding toâ<â0.6 surface event background in the future 200-kg SuperCDMS SNOLAB experiment.This work is supported in part by the National Science Foundation (Grant Nos. AST-9978911, NSF-0847342, PHY-1102795,NSF-1151869, PHY-0542066, PHY-0503729, PHY-0503629, PHY-0503641, PHY-0504224, PHY-0705052,PHY-0801708, PHY-0801712, PHY-0802575, PHY-0847342, PHY-0855299, PHY-0855525, and PHY-1205898), by the Department of Energy (Contract Nos. DE-AC03-76SF00098, DE-FG02-92ER40701, DE-FG02-94ER40823,DE-FG03-90ER40569, DE-FG03-91ER40618, and DESC0004022),by NSERC Canada (Grant Nos. SAPIN 341314 and SAPPJ 386399), and by MULTIDARK CSD2009-00064 and FPA2012-34694. Fermilab is operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359, while SLAC is operated under Contract No. DE-AC02-76SF00515 with the United States Department of
Energy
Autoinflation Leading to Failure of Two-Piece Ambicor Implantable Penile Prosthesis: An Outcome from a Methodical Treatment of Recalcitrant Stuttering Priapism
Introduction. We present the case of a patient who received a two-piece Ambicor penile prosthesis for idiopathic recurrent âstutteringâ priapism refractory to other treatment options. The patient returned unable to deflate the device due to an interesting anatomically induced mechanical failure. Aims. To describe the method and findings of this inflatable prosthesis failure. Results. Prosthesis failure occurred due to restrictive corporal diameter and the unique characteristics of fluid reservoir location in the two-piece inflatable prosthesis. The patient was successfully converted to a semirigid prosthesis with resolution of the pain that was due to his prosthesis autoinflation. Conclusion. Stuttering priapism remains a challenging clinical problem. Penile implantation is a reasonable long-term solution in a patient refractory to less invasive options. In patients with fibrotic corpora, a malleable device should be considered (at least temporarily) if unable to dilate comfortably to 13âmm
DNA repair mechanisms in dividing and non-dividing cells
DNA damage created by endogenous or exogenous genotoxic agents can exist in multiple forms, and if allowed to persist, can promote genome instability and directly lead to various human diseases, particularly cancer, neurological abnormalities, immunodeficiency and premature aging. To avoid such deleterious outcomes, cells have evolved an array of DNA repair pathways, which carry out what is typically a multiple-step process to resolve specific DNA lesions and maintain genome integrity. To fully appreciate the biological contributions of the different DNA repair systems, one must keep in mind the cellular context within they operate. For example, the human body is composed of non-dividing and dividing cell types, including, in the brain, neurons and glial cells. We describe herein the molecular mechanisms of the different DNA repair pathways, and review their roles in non-dividing and dividing cells, with an eye towards how these pathways may regulate the development of neurological disease