398 research outputs found
Electron trapping optical data storage system and applications
A new technology developed at Optex Corporation out-performs all other existing data storage technologies. The Electron Trapping Optical Memory (ETOM) media stores 14 gigabytes of uncompressed data on a single, double-sided 130 mm disk with a data transfer rate of up to 120 megabits per second. The disk is removable, compact, lightweight, environmentally stable, and robust. Since the Write/Read/Erase (W/R/E) processes are carried out photonically, no heating of the recording media is required. Therefore, the storage media suffers no deleterious effects from repeated W/R/E cycling. This rewritable data storage technology has been developed for use as a basis for numerous data storage products. Industries that can benefit from the ETOM data storage technologies include: satellite data and information systems, broadcasting, video distribution, image processing and enhancement, and telecommunications. Products developed for these industries are well suited for the demanding store-and-forward buffer systems, data storage, and digital video systems needed for these applications
Estimating the Causal Effect of Lower Tidal Volume Ventilation on Survival in Patients with Acute Lung Injury
Acute lung injury (ALI) is a condition characterized by acute onset of severe hypoxemia and bliateral pulmonary infiltrates. ALI patients typically require mechanical ventilation in an intensive care unit. Low tidal volume ventilation (LTVV), a time-varying dynamic treatment regime, has been recommended as an effective ventilation strategy. This recommendation was based on the results of the ARMA study, a randomized clinical trial designed to compare low vs. high tidal volume strategies (ARDSNetwork, 2000) . After publication of the trial, some critics focused on the high non-adherence rates in the LTVV arm suggesting that non-adherence occurred because treating physicians felt that deviating from the prescribed regime would improve patient outcomes. In this paper, we seek to address this controversy by estimating the survival distribution in the counterfactual setting where all patients assigned to LTVV followed the regime. Our estimation strategy is based on Robins’s (1986) G-computation formula and fully Bayesian multiple imputation to handle intermittent missing data
Continuous virus filtration: An existing technology with a promising future
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Using Task-fMRI to Explore the Relationship Between Lifetime Cannabis Use and Cognitive Control in Individuals With First-Episode Schizophrenia
While continued cannabis use and misuse in individuals with schizophrenia is associated with a variety of negative outcomes, individuals with a history of use tend to show higher cognitive performance compared to non-users. While this is replicated in the literature, few studies have used task-based functional magnetic resonance imaging (fMRI) to evaluate whether the brain networks underpinning these cognitive features are similarly impacted. Forty-eight first-episode individuals with schizophrenia (FES) with a history of cannabis use (FES + CAN), 28 FES individuals with no history of cannabis use (FES-CAN), and 59 controls (CON) performed the AX-Continuous Performance Task during fMRI. FES+CAN showed higher cognitive control performance (d'-context) compared to FES-CAN (P < .05, ηp 2 = 0.053), and both FES+CAN (P < .05, ηp 2 = 0.049) and FES-CAN (P < .001, ηp 2 = 0.216) showed lower performance compared to CON. FES+CAN (P < .05, ηp 2 = 0.055) and CON (P < 0.05, ηp 2 = 0.058) showed higher dorsolateral prefrontal cortex (DLPFC) activation during the task compared to FES-CAN, while FES+CAN and CON were not significantly different. Within the FES+CAN group, the younger age of initiation of cannabis use was associated with lower IQ and lower global functioning. More frequent use was also associated with higher reality distortion symptoms at the time of the scan. These data are consistent with previous literature suggesting that individuals with schizophrenia and a history of cannabis use have higher cognitive control performance. For the first time, we also reveal that FES+CAN have higher DLPFC brain activity during cognitive control compared to FES-CAN. Several possible explanations for these findings are discussed
Decline of Monarch Butterflies Overwintering in Mexico- Is the Migratory Phenomenon at Risk?
1.During the 2009-2010 overwintering season and following a 15-year downward trend, the total area in Mexico occupied by the eastern North American population of overwintering monarch butterflies reached an all-time low. Despite an increase, it remained low in 2010-2011. 2. Although the data set is small, the decline in abundance is statistically significant using both linear and exponential regression models. 3. Three factors appear to have contributed to reduce monarch abundance: degradation of the forest in the overwintering areas; the loss of breeding habitat in the United States due to the expansion ofGM herbicide-resistant crops, with consequent loss of milkweed host plants, as well as continued land development; and severe weather. 4. This decline calls into question the long-term survival of the monarchs' migratory phenomeno
Superstring in a pp-wave background at finite temperature - TFD approach
A thermodynamical analysis for the type IIB superstring in a pp-wave
background is considered. The thermal Fock space is built and the temperature
SUSY breaking appears naturally by analyzing the thermal vacuum. All the
thermodynamical quantities are derived by evaluating matrix elements of
operators in the thermal Fock space. This approach seems to be suitable to
study thermal effects in the BMN correspondence context.Comment: 15 pages, revtex4, references added, typos correcte
Universality Class of Two-Offspring Branching Annihilating Random Walks
We analyze a two-offspring Branching Annihilating Random Walk ( BAW)
model, with finite annihilation rate. The finite annihilation rate allows for a
dynamical phase transition between a vacuum, absorbing state and a non-empty,
active steady state. We find numerically that this transition belongs to the
same universality class as BAW's with an even number of offspring, ,
and that of other models whose dynamic rules conserve the parity of the
particles locally. The simplicity of the model is exploited in computer
simulations to obtain various critical exponents with a high level of accuracy.Comment: 10 pages, tex, 4 figures uuencoded, also available upon reques
Axial symmetries in lattice QCD with Kaplan fermions
This paper develops in detail a lattice definition of QCD based on the chiral
defect fermions recently introduced by Kaplan. The revised version provides
missing technical details in the proof that non-singlet axial symmetries become
exact in the limit of an infinite fifth dimension. Also several minor errors
are corrected.Comment: LaTeX, 29 p
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