749 research outputs found
Thin shell implies spectral gap up to polylog via a stochastic localization scheme
We consider the isoperimetric inequality on the class of high-dimensional
isotropic convex bodies. We establish quantitative connections between two
well-known open problems related to this inequality, namely, the thin shell
conjecture, and the conjecture by Kannan, Lovasz, and Simonovits, showing that
the corresponding optimal bounds are equivalent up to logarithmic factors. In
particular we prove that, up to logarithmic factors, the minimal possible ratio
between surface area and volume is attained on ellipsoids. We also show that a
positive answer to the thin shell conjecture would imply an optimal dependence
on the dimension in a certain formulation of the Brunn-Minkowski inequality.
Our results rely on the construction of a stochastic localization scheme for
log-concave measures.Comment: 33 page
Consolidating and Dispatching Truck Shipments of Mobil Heavy Petroleum Products
Interfaces, 25, pp. 1-17.Mobil Oil Coporation consolidates and dispatches truck shipments of heavy petroleum products-lubricants in packages and in bulk from 10 lubricant plants nationwide. It dispatches hundreds of orders daily either individually or as consolidated truckloads, using a very nonhomogeneous fleet of Mobil controlled and contract vehicles and common carriers..
Magnetic resonance detects changes in phosphocholine associated with Ras activation and inhibition in NIH 3T3 cells
Ras is frequently mutated in cancer, and novel therapies are being developed to target Ras signalling. To identify non-invasive surrogate markers of Ras activation and inhibition, we used31P magnetic resonance spectroscopy (MRS) and investigated NIH 3T3 cells compared to a mutant ras transfected counterpart. The MR spectra indicated that phosphocholine (PC) levels increased significantly from 3 ± 2 fmol cell−1in NIH 3T3 cells to 13 ± 4  fmol cell−1in the transfected cells. The PC/NTP ratio increased significantly from 0.3 ± 0.1 to 0.7 ± 0.3. This could not be explained by either a faster proliferation rate or by alterations in cell cycle distribution. Both cell lines were treated with simvastatin, 17-AAG and R115777, agents which inhibit Ras signalling. Cell proliferation was inhibited in both cell lines. The spectrum of NIH 3T3 cells was not affected by treatment. In contrast, in the ras transfected cells growth inhibition was associated with an average 35 ± 5% drop in PC levels and a comparable drop in PC/NTP. Thus the MRS visible increase in phosphocholine is associated with Ras activation, and response to treatment is associated with partial reversal of phosphocholine increase in ras transfected cells. MRS might therefore be a useful tool in detecting Ras activation and its inhibition following targeted therapies. © 2001 Cancer Research Campaign http://www.bjcancer.co
Automated Security Analysis of IoT Software Updates
IoT devices often operate unsupervised in ever-changing environments for several years. Therefore, they need to be updated on a regular basis. Current approaches for software updates on IoT, like the recent SUIT proposal, focus on granting integrity and confidentiality but do not analyze the content of the software update, especially the IoT application which is deployed to IoT devices. To this aim, in this paper, we present IoTAV, an automated software analysis framework for systematically verifying the security of the applications contained in software updates w.r.t. a given security policy. Our proposal can be adopted transparently by current IoT software updates workflows. We prove the viability of IoTAV by testing our methodology on a set of actual RIOT OS applications. Experimental results indicate that the approach is viable in terms of both reliability and performance, leading to the identification of 26 security policy violations in 31 real-world RIOT applications
Scissors mode of trapped dipolar gases
We study the scissors modes of dipolar boson and fermion gases trapped in a
spherically symmetric potential. We use the harmonic oscillator states to solve
the time-dependent Gross-Pitaevskii equation for bosons and the time-dependent
Hartree-Fock equation for fermions. It is pointed out that the scissors modes
of bosons and fermions can be of quite different nature
Standardization for oncologic head and neck surgery
The inherent variability in performing specific surgical procedures for head and neck cancer remains a barrier for accurately assessing treatment outcomes, particularly in clinical trials. While non-surgical modalities for cancer therapeutics have evolved to become far more uniform, there remains the challenge to standardize surgery. The purpose of this review is to identify the barriers in achieving uniformity and to highlight efforts by surgical groups to standardize selected operations and nomenclature. While further improvements in standardization will remain a challenge, we must encourage surgical groups to focus on strategies that provide such a level.Peer reviewe
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