356 research outputs found
Optimizing floating guard ring designs for FASPAX N-in-P silicon sensors
FASPAX (Fermi-Argonne Semiconducting Pixel Array X-ray detector) is being
developed as a fast integrating area detector with wide dynamic range for time
resolved applications at the upgraded Advanced Photon Source (APS.) A burst
mode detector with intended \mbox{13 MHz} image rate, FASPAX will also
incorporate a novel integration circuit to achieve wide dynamic range, from
single photon sensitivity to x-rays/pixel/pulse. To achieve
these ambitious goals, a novel silicon sensor design is required. This paper
will detail early design of the FASPAX sensor. Results from TCAD optimization
studies, and characterization of prototype sensors will be presented.Comment: IEEE NSS-MIC 2015 Conference recor
From Beyond the Stars: Innovation and Inspiration in Meiji Japanese Art, 1868-1912
Design by Tom Wagner. Photography by the Kruizenga Art Museum, Tom Wagner, and Curatorial Assistance/WorldBridge Art, Inc. Produced by Storming the Castle Pictures (StCP) for the Kruizenga Art Museum as a catalogue for the exhibition, From Beyond the Stars, August 29 - December 16, 2017. Photographs, text and design copyright 2017 Hope College and Tom Wagner, no reproduction or use of any material, in whole or in part, without the written permission of Hope College.https://digitalcommons.hope.edu/kam_catalogs/1001/thumbnail.jp
Interventions to increase research publications in graduate medical education trainees: a systematic review.
Introduction: Competency-based educational models recommend trainee exposure to research, but the best methods for Graduate Medical Education (GME) programs to accomplish this have not been clarified. The objective of this study was to quantify published interventions to generate resident research and compare effectiveness among those interventions.
Material and methods: A systematic review of English-language articles of studies of GME programs was performed, describing resident research interventions and quantifying the number of publications as an outcome.
Results: The search produced 13,688 potentially relevant articles, and included 47 articles in the final synthesis. Publication effectiveness was calculated as publications per year. The top ten programs for publication effectiveness were compared to others for interventions chosen. Interventions were characterized as research director, protected time, research requirement, research mentor, curricula, research assistant, biostatistician, information technology support, research fund, pay-for-performance plans, and celebration of accomplishments. Total number of different interventions was not significantly associated with primary outcome (
Conclusions: Leadership interventions (directors, curricula) are associated with successful GME research efforts
Design and performance of the Fermilab Constant Fraction Discriminator ASIC
We present the design and performance characterization results of the novel
Fermilab Constant Fraction Discriminator ASIC (FCFD) developed to readout low
gain avalanche detector (LGAD) signals by directly using a constant fraction
discriminator (CFD) to measure signal arrival time. Silicon detectors with time
resolutions less than 30 ps will play a critical role in future collider
experiments, and LGADs have been demonstrated to provide the required time
resolution and radiation tolerance for many such applications. The FCFD has a
specially designed discriminator that is robust against amplitude variations of
the signal from the LGAD that normally requires an additional correction step
when using a traditional leading edge discriminator based measurement. The
application of the CFD directly in the ASIC promises to be more reliable and
reduces the complication of timing detectors during their operation. We will
present a summary of the measured performance of the FCFD for input signals
generated by internal charge injection, LGAD signals from an infrared laser,
and LGAD signals from minimum-ionizing particles. The mean time response for a
wide range of LGAD signal amplitudes has been measured to vary no more than 15
ps, orders of magnitude more stable than an uncorrected leading edge
discriminator based measurement, and effectively removes the need for any
additional time-walk correction. The measured contribution to the time
resolution from the FCFD ASIC is also found to be 10 ps for signals with charge
above 20 fC
Synergism between Porcine Reproductive and Respiratory
This study was conducted to investigate the effects of exposure to porcine reproductive and respiratory syndrome virus, Salmonella choleraesuis, and stress on young swine. Five-week-old segregated early weaned pigs were randomly assigned to one of eight treatments consisting of all possible combinations of three factors: S. choleraesuis (SC) on day zero, porcine reproductive and respiratory syndrome virus (PRRSV) on day three, and dexamethasone (DEX) on days three to seven. DEX was used as a proxy for stress. Treatment differences were seen in performance parameters, levels and duration of SC shedding, level and distribution of SC in tissues, clinical disease, and mortality. The results of this study provided evidence to support field observations that clinical outbreaks of PRRS are the result of interactions among concurrent infections and stressors
Improving management of a mid-Atlantic coastal barrier island through assessment of habitat condition
AbstractTo achieve desired environmental outcomes, environmental condition and trends need to be rigorously measured and communicated to resource managers, scientists, and a broader general audience. However, there is often a disconnect between responsive ecosystem monitoring and decision making for strategic long-term management. This project demonstrates how historical monitoring data can be synthesized and used for future planning and decision making, thereby closing the management feedback cycle. This study linked disparate datasets, collected for a variety of purposes and across multiple temporal and spatial scales, in order to assess and quantify current habitat conditions. The results inform integrated resource management decision-making at Assateague Island National Seashore (Maryland and Virginia, USA) by using ecological reference conditions to identify monitoring needs, areas of high vulnerability, and areas with potential for improved management. The approach also provides a framework that can be applied in the future to assess the effectiveness of these management decisions on the condition of island habitats, and is a replicable demonstration of incorporating diverse monitoring datasets into an adaptive management cycle
Battery Health Quantification for TDRS Spacecraft by Using Signature Discriminability Measurement
The NASA/GSFC Space Network Project Office (SN) currently operates a constellation of ten geosynchronous TDRS spacecraft launched over the past 30 years. The SN project collects up to 16.5 Gigabytes of telemetry every month. Generally, the spacecraft health and functionality are obtained by the use of real-time telemetry data for the multiple spacecraft subsystems, which are transmitted to the main ground station at the White Sands Complex in Las Cruces, NM. Recently, the SN has instituted a program of Big Data to analyze the large amounts of data using a variety of tools including Machine Learning, Artificial Intelligence, development of training sets, and a variety of mathematical modeling tools. The goal is to improve spacecraft management and obtain a more accurate prediction of the spacecraft end of life. The combination of these efforts with those of the Aerospace Corporation, which has a contract with the SN to produce yearly reliability estimates for the TDRS fleet, will be performed. This paper presents a new concept called telemetry quality quantification (TQQ) and discusses the progress that has been made in battery performance estimation for the second-generation TDRS spacecraft using a signature discriminability measures (SDM) algorithm combined with the Aerospace Corp. battery life estimation models. This activity is important because many of the TDRS fleet of spacecraft have exceeded their on-orbit design lifetime and, therefore, NASA must carefully manage the spacecraft to continue operations while avoiding an end-of-mission scenario that leaves a non-functioning spacecraft in geosynchronous orbit
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A vertically integrated pixel readout device for the Vertex Detector at the International Linear Collider
3D-Integrated Circuit technology enables higher densities of electronic circuitry per unit area without the use of nanoscale processes. It is advantageous for mixed mode design with precise analog circuitry because processes with conservative feature sizes typically present lower process dispersions and tolerate higher power supply voltages, resulting in larger separation of a signal from the noise floor. Heterogeneous wafers (different foundries or different process families) may be combined with some 3D integration methods, leading to the optimization of each tier in the 3D stack. Tracking and vertexing in future High-Energy Physics (HEP) experiments involves construction of detectors composed of up to a few billions of channels. Readout electronics must record the position and time of each measurement with the highest achievable precision. This paper reviews a prototype of the first 3D readout chip for HEP, designed for a vertex detector at the International Linear Collider. The prototype features 20 x 20 {micro}m{sup 2} pixels, laid out in an array of 64 x 64 elements and was fabricated in a 3-tier 0.18 {micro}m Fully Depleted SOI CMOS process at MIT-Lincoln Laboratory. The tests showed correct functional operation of the structure. The chip performs a zero-suppressed readout. Successive submissions are planned in a commercial 3D bulk 0.13 {micro}m CMOS process to overcome some of the disadvantages of an FDSOI process
Mutations in pericentrin cause Seckel syndrome with defective ATR-dependent DNA damage signaling
Large brain size is one of the defining characteristics of modern humans. Seckel syndrome (MIM 210600), a disorder of markedly reduced brain and body size, is associated with defective ATR-dependent DNA damage signaling. Only a single hypomorphic mutation of ATR has been identified in this genetically heterogeneous condition. We now report that mutations in the gene encoding pericentrin (PCNT)--resulting in the loss of pericentrin from the centrosome, where it has key functions anchoring both structural and regulatory proteins--also cause Seckel syndrome. Furthermore, we find that cells of individuals with Seckel syndrome due to mutations in PCNT (PCNT-Seckel) have defects in ATR-dependent checkpoint signaling, providing the first evidence linking a structural centrosomal protein with DNA damage signaling. These findings also suggest that other known microcephaly genes implicated in either DNA repair responses or centrosomal function may act in common developmental pathways determining human brain and body size
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