856 research outputs found
Distributed state verification in the smart grid using physical attestation
A cyber process in a distributed system can fabricate its internal state in its communications with its peers. These state fabrications can cause other processes in the distributed system to make incorrect control decisions. Cyber-physical systems have a unique advantage in the detection of falsified states because processes typically have observable effects on a shared physical infrastructure. This physical infrastructure acts as a high-integrity message channel that broadcasts changes in individual process states. The objective of this research is to demonstrate that there are cases where physical feedback from the shared infrastructure can be used to detect state fabrications. To that end, this work introduces a distributed security mechanism called physical attestation that detects state fabrications in the future smart grid. Graph theory is used to prove that physical attestation works in general smart grid topologies, and the theory is supported with experimental results obtained from a smart grid test bed --Abstract, page iii
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Catalyzed Gasoline Particulate Filters Reduce Secondary Organic Aerosol Production from Gasoline Direct Injection Vehicles
The
effects of photochemical aging on exhaust emissions from two
light-duty vehicles with gasoline direct injection (GDI) engines equipped
with and without catalyzed gasoline particle filters (GPFs) were investigated
using a mobile environmental chamber. Both vehicles with and without
the GPFs were exercised over the LA92 drive cycle using a chassis
dynamometer. Diluted exhaust emissions from the entire LA92 cycle
were introduced to the mobile chamber and subsequently photochemically
reacted. It was found that the addition of catalyzed GPFs will significantly
reduce tailpipe particulate emissions and also provide benefits in
gaseous emissions, including nonmethane hydrocarbons (NMHC). Tailpipe
emissions composition showed important changes with the use of GPFs
by practically eliminating black carbon and increasing the fractional
contribution of organic mass. Production of secondary organic aerosol
(SOA) was reduced with GPF addition, but was also dependent on engine
design which determined the amount of SOA precursors at the tailpipe.
Our findings indicate that SOA production from GDI vehicles will be
reduced with the application of catalyzed GPFs through the mitigation
of reactive hydrocarbon precursors
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Physical, chemical, and toxicological characteristics of particulate emissions from current technology gasoline direct injection vehicles
Patient recruitment into clinical studies of solid malignancies during the COVID-19 pandemic in a tertiary cancer center
Background and purpose: To analyze clinical trial activities and patient recruitment numbers into prospective clinical studies for solid malignancies during the COVID-19 pandemic in a tertiary cancer center.
Materials and methods: Patient recruitment numbers in prospective clinical studies of solid malignancies were retrospectively analyzed for the years 2019 – 2021 at the Comprehensive Cancer Center Zurich (CCCZ). Changes in recruitment numbers were tested for association with organ-specific subunits, as well as organizational and treatment-related trial characteristics. To assess differences between categorical variables, Chi-squared test was used. For uni- and multivariate analysis, Cox proportional hazards were calculated.
Results: In 2019, there were a total of 107 studies (registry trials, clinical phase I-III trials, and translational studies) recruiting 304 patients at the CCCZ. During the COVID-19 pandemic in 2020 and 2021, there were 120 and 125 active trials with a total recruitment of 355 and 666 patients, respectively. No significant differences between the subunits and study characteristics in changes of patient recruitment in clinical phase I-III trials were identified when the year prior to the COVID-19 pandemic (2019) was compared to the first year of the pandemic (2020) and to 2020-2021.
Conclusions: Despite healthcare systems around the world have experienced significant disruption due to the COVID-19 pandemic, data from our tertiary cancer center showed that clinical trial activities were maintained at a high level during the pandemic
Effects of driving conditions on secondary aerosol formation from a GDI vehicle using an oxidation flow reactor
A comprehensive study on the effects of photochemical aging on exhaust emissions from a vehicle equipped with a gasoline direct injection engine when operated over seven different driving cycles was assessed using an oxidation flow reactor. Both primary emissions and secondary aerosol production were measured over the Federal Test Procedure (FTP), LA92, New European Driving Cycle (NEDC), US06, and the Highway Fuel Economy Test (HWFET), as well as over two real-world cycles developed by the California Department of Transportation (Caltrans) mimicking typical highway driving conditions. We showed that the emissions of primary particles were largely depended on cold-start conditions and acceleration events. Secondary organic aerosol (SOA) formation also exhibited strong dependence on the cold-start cycles and correlated well with SOA precursor emissions (i.e., non-methane hydrocarbons, NMHC) during both cold-start and hot-start cycles (correlation coefficients 0.95–0.99), with overall emissions of ∼68–94 mg SOA per g NMHC. SOA formation significantly dropped during the hot-running phases of the cycles, with simultaneous increases in nitrate and ammonium formation as a result of the higher nitrogen oxide (NOx) and ammonia emissions. Our findings suggest that more SOA will be produced during congested, slow speed, and braking events in highways.acceptedVersionPeer reviewe
DREADD agonist 21 is an effective agonist for muscarinic-based DREADDs in vitro and in vivo
Chemogenetic tools such as designer receptors exclusively activated by designer drugs (DREADDs) are routinely used to modulate neuronal and non-neuronal signaling and activity in a relatively noninvasive manner. The first generation of DREADDs were templated from the human muscarinic acetylcholine receptor family and are relatively insensitive to the endogenous agonist acetylcholine but instead are activated by clozapine-N-oxide (CNO). Despite the undisputed success of CNO as an activator of muscarinic DREADDs, it has been known for some time that CNO is subject to a low rate of metabolic conversion to clozapine, raising the need for alternative chemical actuators of muscarinic-based DREADDs. Here we show that DREADD agonist 21 (C21) (11-(1-piperazinyl)-5H-dibenzo[b,e][1,4]diazepine) is a potent and selective agonist at both excitatory (hM3Dq) and inhibitory (hM4Di) DREADDs and has excellent bioavailability, pharmacokinetic properties, and brain penetrability. We also show that C21-induced activation of hM3Dq and hM4Di in vivo can modulate bidirectional feeding in defined circuits in mice. These results indicate that C21 represents an alternative to CNO for in vivo studies where metabolic conversion of CNO to clozapine is a concern
Treatment of Chronic Fatigue Syndrome: Findings, Principles and Strategies
Chronic fatigue syndrome (CFS) is a debilitating condition characterized by serious medically unexplained mental and physical fatigue. The high prevalence and both direct and indirect health costs of CFS patients represent a huge problem for contemporary health care. Moreover, the prognosis of CFS, even when treated, is often poor. In this paper, we first critically review current evidence based treatments of CFS. Second, we discuss the growing insights into the etiopathogenesis of CFS, and the need to translate and integrate these insights into future treatments. In particular, we formulate a pragmatic and empirically testable treatment approach, tailored to the individual needs of patients, which aims at restoring the mental and physical equilibrium of CFS patients by trying to bring about sustained life style changes
The Mice at play in the CALIFA survey: A case study of a gas-rich major merger between first passage and coalescence
We present optical integral field spectroscopy (IFS) observations of the
Mice, a major merger between two massive (>10^11Msol) gas-rich spirals NGC4676A
and B, observed between first passage and final coalescence. The spectra
provide stellar and gas kinematics, ionised gas properties and stellar
population diagnostics, over the full optical extent of both galaxies. The Mice
provide a perfect case study highlighting the importance of IFS data for
improving our understanding of local galaxies. The impact of first passage on
the kinematics of the stars and gas has been significant, with strong bars
likely induced in both galaxies. The barred spiral NGC4676B exhibits a strong
twist in both its stellar and ionised gas disk. On the other hand, the impact
of the merger on the stellar populations has been minimal thus far: star
formation induced by the recent close passage has not contributed significantly
to the global star formation rate or stellar mass of the galaxies. Both
galaxies show bicones of high ionisation gas extending along their minor axes.
In NGC4676A the high gas velocity dispersion and Seyfert-like line ratios at
large scaleheight indicate a powerful outflow. Fast shocks extend to ~6.6kpc
above the disk plane. The measured ram pressure and mass outflow rate
(~8-20Msol/yr) are similar to superwinds from local ULIRGs, although NGC4676A
has only a moderate infrared luminosity of 3x10^10Lsol. Energy beyond that
provided by the mechanical energy of the starburst appears to be required to
drive the outflow. We compare the observations to mock kinematic and stellar
population maps from a merger simulation. The models show little enhancement in
star formation during and following first passage, in agreement with the
observations. We highlight areas where IFS data could help further constrain
the models.Comment: 23 pages, 13 figures, accepted to A&A. A version with a complete set
of high resolution figures is available here:
http://www-star.st-and.ac.uk/~vw8/resources/mice_v8_astroph.pd
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