bluuebunny/crossref_metadata_2025 huggingface dataset:
Fast and continuous patterning on the surface of plastic fiber by using thermal roller imprint
Authors: Ohtomo Akihiro , Kokubo Mitsunori , Goto Hiroshi , Mekaru Harutaka , Takagi Hideki
Published: September 2012

The authors succeeded in producing high-speed continuous patterning on the surface of plastic fiber at a feeding speed of 20 m/min by using a system they developed employing thermal roller imprint methodology. In this method, a cylindrical mold with seamless microstructures formed on its surface was used, wherein a plastic fiber is pressed between the cylindrical mold and a backup roller and is then run for imprinting. Here, the movement of the cylindrical mold in the direction of space-change between the mold and the backup roller can be precisely controlled, and the press force during the imprinting can be measured by a load cell located beneath the backup roller. The cylindrical mold and the backup roller are heated up to 250 °C and are rotated synchronously, imparting a forward-linear motion to the plastic fiber and thereby making continuous patterning of microstructures possible. Since the press force feedback system during high-speed imprinting cannot be adequately controlled, the authors devised a scheme where the system memorizes the press positions corresponding to the rotating angles of the cylindrical mold at low feeding speed under a controlled press force. Here, the periodic variation of the center-to-center distance between the cylindrical mold and the backup roller can be measured at set intervals and, by using the memorized relationship between the rotational angle and press position, the position of the cylindrical mold is then moved. Finally, the authors imprinted 50 μm high microstructures onto the surface of the plastic optical fiber whose diameter was 250 μm. As a result, when the press position was fixed, the standard deviation of the press force was 6.86 N; however, this value dropped to 2.80 N when the improved control method was employed. The range of depth variation was 8.0 μm when the press position was fixed, and this number went down to 2.2 μm when the improved control method was employed.
Peroxide Promotes Survival
Authors: Wong Wei
Published: September 2012

In
Caenorhabditis elegans
, hydrogen peroxide can stimulate the transcriptional activation of genes involved in lipid biosynthesis.
Identification and Evaluation of Twin-Arginine Translocase Inhibitors
Authors: Vasil Michael L. , Tomaras Andrew P. , Pritchard Arthur E.
Published: September 2012

The twin-arginine translocase (TAT) in some bacterial pathogens, including
Pseudomonas aeruginosa
,
Burkholderia pseudomallei
, and
Mycobacterium tuberculosis
, contributes to pathogenesis by translocating extracellular virulence determinants across the inner membrane into the periplasm, thereby allowing access to the Xcp (type II) secretory system for further export in Gram-negative organisms, or directly to the outside surface of the cell, as in
M. tuberculosis
. TAT-mediated secretion appreciably contributes to virulence in both animal and plant models of bacterial infection. Consequently, TAT function is an attractive target for small-molecular-weight compounds that alone or in conjunction with extant antimicrobial agents could become novel therapeutics. The TAT-transported hemolytic phospholipase C (PlcH) of
P. aeruginosa
and its multiple orthologs produced by the above pathogens can be detected by an accurate and reproducible colorimetric assay using a synthetic substrate that detects phospholipase C activity. Such an assay could be an effective indicator of TAT function. Using carefully constructed recombinant strains to precisely control the expression of PlcH, we developed a high-throughput screening (HTS) assay to evaluate, in duplicate, >80,000 small-molecular-weight compounds as possible TAT inhibitors. Based on additional TAT-related functional assays, purified PlcH protein inhibition experiments, and repeat experiments of the initial screening assay, 39 compounds were selected from the 122 initial hits. Finally, to evaluate candidate inhibitors for TAT specificity, we developed a TAT titration assay that determines whether inhibition of TAT-mediated secretion can be overcome by increasing the levels of TAT expression. The compounds
N
-phenyl maleimide and Bay 11-7082 appear to directly affect TAT function based on this approach.
Importance of the Genetic Diversity within the Mycobacterium tuberculosis Complex for the Development of Novel Antibiotics and Diagnostic Tests of Drug Resistance
Authors: Köser Claudio U. , Feuerriegel Silke , Summers David K. , Archer John A. C. , Niemann Stefan
Published: September 2012

Despite being genetically monomorphic, the limited genetic diversity within the
Mycobacterium tuberculosis
complex (MTBC) has practical consequences for molecular methods for drug susceptibility testing and for the use of current antibiotics and those in clinical trials. It renders some representatives of MTBC intrinsically resistant against one or multiple antibiotics and affects the spectrum and consequences of resistance mutations selected for during treatment. Moreover, neutral or silent changes within genes responsible for drug resistance can cause false-positive results with hybridization-based assays, which have been recently introduced to replace slower phenotypic methods. We discuss the consequences of these findings and propose concrete steps to rigorously assess the genetic diversity of MTBC to support ongoing clinical trials.
Genome Sequence of Reyranella massiliensis, a Bacterium Associated with Amoebae
Authors: Pagnier Isabelle , Croce Olivier , Robert Catherine , Raoult Didier , La Scola Bernard
Published: September 2012

Reyranella massiliensis
is an
Alphaproteobacterium
member of the class
Rhodospirillaceae
, growing in amoebae. We sequenced the genome of type strain 521
T
. It is composed of a 5,792,218-bp chromosome and encodes 5,675 protein-coding genes and 53 RNA genes, including 3 rRNA genes.
Draft Genome Sequence of Bacillus endophyticus 2102
Authors: Lee Yong-Jik , Lee Sang-Jae , Kim Sun Hong , Lee Sang Jun , Kim Byoung-Chan , Lee Han-Seung , Jeong Haeyoung , Lee Dong-Woo
Published: September 2012

Bacillus endophyticus
2102 is an endospore-forming, plant growth-promoting rhizobacterium isolated from a hypersaline pond in South Korea. Here we present the draft sequence of
B. endophyticus
2102, which is of interest because of its potential use in the industrial production of algaecides and bioplastics and for the treatment of industrial textile effluents.
Genome Sequence of the Methanotrophic Poly-β-Hydroxybutyrate Producer Methylocystis parvus OBBP
Authors: del Cerro Carlos , García Jesús M. , Rojas Antonia , Tortajada Marta , Ramón Daniel , Galán Beatriz , Prieto María A. , García José L.
Published: September 2012

Methylocystis parvus
OBBP is an obligate methylotroph considered the type species of the genus
Methylocystis
. Two
pmoCAB
particulate methane monooxygenase operons and one additional singleton
pmoC
paralog were identified in the sequence. No evidence of genes encoding soluble methane monooxygenase was found. Comparison of
M. parvus
OBBP and
Methylocystis
sp. strain Rockwell (ATCC 49242) suggests that both species should be taxonomically classified in different genera.
Genome Sequence of a Cold-Adaptable Sulfamethoxazole-Degrading Bacterium, Pseudomonas psychrophila HA-4
Authors: Jiang Benchao , Cui Di , Li Ang , Gai Zhonghui , Ma Fang , Yang Jixian , Ren Nanqi
Published: September 2012

Pseudomonas psychrophila
HA-4 is a cold-adaptable, sulfamethoxazole-degrading bacterium. The genes related to its cold adaptation mechanism and sulfamethoxazole metabolism were unknown. We present the draft genome of strain HA-4. It could provide further insight into the sulfamethoxazole-degrading mechanism of strain HA-4.
Cryptococcal Genotype Influences Immunologic Response and Human Clinical Outcome after Meningitis
Authors: Wiesner Darin L. , Moskalenko Oleksandr , Corcoran Jennifer M. , McDonald Tami , Rolfes Melissa A. , Meya David B. , Kajumbula Henry , Kambugu Andrew , Bohjanen Paul R. , Knight Joseph F. , Boulware David R. , Nielsen Kirsten
Published: September 2012

In sub-Saharan Africa, cryptococcal meningitis (CM) continues to be a predominant cause of AIDS-related mortality. Understanding virulence and improving clinical treatments remain important. To characterize the role of the fungal strain genotype in clinical disease, we analyzed 140Cryptococcusisolates from 111 Ugandans with AIDS and CM. Isolates consisted of 107 nonredundantCryptococcus neoformansvar.grubiistrains and 8C. neoformansvar.grubii/neoformanshybrid strains. Multilocus sequence typing (MLST) was used to characterize genotypes, yielding 15 sequence types and 4 clonal clusters. The largest clonal cluster consisted of 74 isolates. The results of Burst and phylogenetic analysis suggested that theC. neoformansvar.grubiistrains could be separated into three nonredundant evolutionary groups (Burst group 1 to group 3). Patient mortality was differentially associated with the different evolutionary groups (P= 0.04), with the highest mortality observed among Burst group 1, Burst group 2, and hybrid strains. Compared to Burst group 3 strains, Burst group 1 strains were associated with higher mortality (P= 0.02), exhibited increased capsule shedding (P= 0.02), and elicited a more pronounced Th2response duringex vivocytokine release assays with strain-specific capsule stimulation (P= 0.02). The results of these analyses suggest that cryptococcal strain variation can be an important determinant of human immune responses and mortality.

IMPORTANCECryptococcus neoformansis a common life-threatening human fungal pathogen that is responsible for an estimated 1 million cases of meningitis in HIV-infected patients annually. Virulence factors that are important in human disease have been identified, yet the impacts of the fungal strain genotype on virulence and outcomes of human infection remain poorly understood. Using an analysis of strain variation based onin vitroassays and clinical data from Ugandans living with AIDS and cryptococcal infection, we report that strain genotype predicts the type of immune response and mortality risk. These studies suggest that knowledge of the strain genotype during human infections could be used to predict disease outcomes and lead to improved treatment approaches aimed at targeting the specific combination of pathogen virulence and host response.
Thermoreversible gelation polymer as an embolic material for aneurysm treatment: a delivery device for dermal fibroblasts and basic fibroblast growing factor into experimental aneurysms in rats
Authors: Dobashi Hisashi , Akasaki Yasuharu , Yuki Ichiro , Arai Takao , Ohashi Hiroki , Murayama Yuichi , Takao Hiroyuki , Abe Toshiaki
Published: September 2012

Background

This study evaluates whether thermoreversible gelation polymer (TGP) can be used as a delivery device to deploy dermal fibroblasts and cytokines into experimental aneurysms in rats.

Methods

The right common iliac artery of rats was surgically ligated and an experimental aneurysm was created by applying exogenous elastase. Seven days later, two aneurysms were harvested and used as controls (Group A), two were embolized with pure TGP (Group B), two were embolized with TGP and basic fibroblast growth factor (bFGF) (Group C) and two were embolized with TGP loaded with rat dermal fibroblasts (Group D). The aneurysms were also embolized with TGP mixed with dermal fibroblasts and bFGF at different concentrations (10 ng/ml: Group E (n=2), 100 ng/ml: Group F (n=2), 1000 ng/ml: Group G (n=2)). Each aneurysm sample was harvested after 7 days and histologic analyses were performed.

Results

The most advanced thrombus organization in the aneurysm, such as prominent fibroblast proliferation and collagen deposition, was observed in Groups E, F and G, although there was no noticeable difference between the groups. Moderate thrombus organization was seen in Group D and minimal thrombus organization was seen in Groups B and C.

Conclusions

TGP mixed with both dermal fibroblasts and bFGF induced the most advanced thrombus organization in the experimental aneurysms followed by TGP mixed only with dermal fibroblasts. TGP may be useful as a delivery device to deploy fibroblasts and cytokines into aneurysms.
Pervious concrete pavement performance modeling: an empirical approach in cold climates
Authors: Golroo Amir , Tighe Susan L.
Published: September 2012

Pervious concrete pavement (PCP) is an appropriate means to meet growing environmental demands. To apply pervious concrete as a pavement, its performance should be studied over its life span. This research aims to develop empirical performance models based on a proposed condition index through incorporation of integrated laboratory and field work. Since no condition index has been developed for PCP to date, first, a condition index is developed. The condition index is proposed as a combination of two indices: a surface distress index and a functional performance index. Two sources of data have been collected to develop performance models including panel rating and field investigations. Performance models are developed in two phases using regression analysis techniques. In phase I, performance models are presented as functions of a surface distress index and a functional performance index, while in phase II, performance models are correlated with pavement age and successfully validated.
Real-time travel time predictor for route guidance consistent with driver behavior
Authors: Xu Tian-dong , Hao Yuan , Peng Zhong-ren , Sun Li-jun
Published: September 2012

Providing reliable real-time travel time information is a critical challenge to all existing traffic routing systems. This study develops a new model for estimating and predicting real-time traffic conditions and travel times for variable message signs-based route guidance system. The proposed model is based on real-time limited detected traffic data, stochastic nonlinear macroscopic traffic flow model, and adaptive Kalman filtering theory. The method has the following main features: (1) real-time estimation and prediction of traffic conditions on a network level using limited traffic detectors, (2) travel time prediction in free flow and congested flow, and (3) prediction of drivers’ en-route diversion behavior. Field testing is conducted based on the Route Guidance Pilot Project sponsored by the National Science and Technology Ministry of China. The achieved testing results are satisfactory and have potential use for future works and field applications.
TRIPLE-HORIZON SPHERICALLY SYMMETRIC SPACETIME AND HOLOGRAPHIC PRINCIPLE
Authors: DYMNIKOVA IRINA
Published: September 2012

We present a family of spherically symmetric spacetimes, specified by the density profile of a vacuum dark energy, which have the same global structure as the de Sitter spacetime but the reduced symmetry which leads to a time-evolving and spatially inhomogeneous cosmological term. It connects smoothly two de Sitter vacua with different values of cosmological constant and corresponds to anisotropic vacuum dark fluid defined by symmetry of its stress–energy tensor which is invariant under the radial boosts. This family contains a special class distinguished by dynamics of evaporation of a cosmological horizon which evolves to the triple horizon with the finite entropy, zero temperature, zero curvature, infinite positive specific heat and infinite scrambling time. Nonzero value of the cosmological constant in the triple-horizon spacetime is tightly fixed by quantum dynamics of evaporation of the cosmological horizon.
COUNTERPARTY RISK PRICING: IMPACT OF CLOSEOUT AND FIRST-TO-DEFAULT TIMES
Authors: BRIGO DAMIANO , BUESCU CRISTIN , MORINI MASSIMO
Published: September 2012

In the absence of a universally accepted procedure for the credit valuation adjustment (CVA) calculation, we compare a number of different bilateral counterparty valuation adjustment (BVA) formulas. First we investigate the impact of the choice of the closeout convention used in the formulas. Important consequences on default contagion manifest themselves in a rather different way depending on which closeout formulation is used (risk-free or replacement), and on default dependence between the two entities in the deal. Second we compare the full bilateral formula with an approximation that is based on subtracting two unilateral credit valuation adjustment (UCVA) formulas. Although the latter might be attractive for its instantaneous implementation once one has a unilateral CVA system, it ignores the impact of the first-to-default time, when closeout procedures are ignited. We illustrate in a number of realistic cases both the contagion effect due to the closeout convention, and the CVA pricing error due to ignoring the first-to-default time.
DYNAMICAL HETEROGENEITIES IN A TWO-DIMENSIONAL DRIVEN GLASSY MODEL: CURRENT FLUCTUATIONS AND FINITE SIZE EFFECTS
Authors: TURCI FRANCESCO , PITARD ESTELLE
Published: September 2012

In this article, we demonstrate that in a transport model of particles with kinetic constraints, long-lived spatial structures are responsible for the blocking dynamics and the decrease of the current at strong driving field. Coexistence between mobile and blocked regions can be anticipated by a first-order transition in the large deviation function for the current. By a study of the system under confinement, we are able to study finite-size effects and extract a typical length between mobile regions.
LOCAL WAVELET TRANSFORM ON THE SMOOTH SURFACE OF ROTATION CLASS
Authors: WANG BAOQIN , WANG GANG , ZHOU XIAOHUI
Published: September 2012

For the smooth surface of rotation class M, the explicit construction of two local flattening maps p are given. By virtue of the inverse projection p-1, where the bijection projection p is the local flattening map from a two-dimensional smooth surface M of rotation class to a plane, the local wavelet transform on M can be generated from wavelet transform on a plane. For the two examples of the quadratic parameter rotation surface and parabolic general rotation surface, by using the two local flattening maps p respectively, the construction of the local dilation is systematically studied, and local wavelet transform of them is offered. We also show the local wavelet graphical representation on the quadratic parameter rotation surface and parabolic general rotation surface. Finally, the inverse transform formula of the local wavelet transform, that is, the reconstruction formula is also offered.
SUPERVISED REGULARIZATION LOCALITY-PRESERVING PROJECTION METHOD FOR FACE RECOGNITION
Authors: CHEN WEN-SHENG , WANG WEI , YANG JIAN-WEI , TANG YUAN YAN
Published: September 2012

Locality-preserving projection (LPP) is a promising manifold-based dimensionality reduction and linear feature extraction method for face recognition. However, there exist two main issues in traditional LPP algorithm. LPP does not utilize the class label information at the training stage and its performance will be affected for classification tasks. In addition, LPP often suffers from small sample size (3S) problem, which occurs when the dimension of input pattern space is greater than the number of training samples. Under this situation, LPP fails to work. To overcome these two limitations, this paper presents a novel supervised regularization LPP (SRLPP) approach based on a supervised graph and a new regularization strategy. It theoretically proves that regularization matrix [Formula: see text] approaches to the original one as the regularized parameter tends to zero. The proposed SRLPP method is subsequently applied to face recognition. The experiments are conducted on two publicly available face databases, namely ORL database and FERET database. Compared with some existing LDA-based and LPP-based linear feature extraction approaches, experimental results show that our SRLPP approach gives superior performance.
MULTIVARIATE CALIBRATION WITH SUPPORT VECTOR REGRESSION BASED ON RANDOM PROJECTION
Authors: CHEN SHOUYIN , PENG JIANGTAO
Published: September 2012

A multivariate calibration method with support vector regression based on random projection is proposed. The proposed algorithm reduces the dimensionality of high-dimensional spectral data by random projection, and then performs quantitative calibration using support vector regression. Support vector regression method can handle nonlinear regression which is usually encountered in spectral analysis. Moreover, model calculation and optimization on the projected data are relatively fast. A comparative study of the proposed method and partial least squares on four spectral datasets is presented. The proposed method allows drastic reduction in data size and computing time, while preserving the predict performance.
WAVELET-BASED ESTIMATION OF MODAL PARAMETERS OF A VEHICLE INVOLVED IN A FULL-SCALE IMPACT
Authors: PAWLUS WITOLD , KARIMI HAMID REZA , ROBBERSMYR KJELL G.
Published: September 2012

In this paper, a wavelet-based approach is presented for estimation of vehicle modal parameters. The acceleration of a colliding vehicle is measured in its center of gravity — this crash pulse contains detailed information about vehicle behavior throughout a collision. Three types of signal analysis are elaborated here: time domain analysis (i.e. description of kinematics of a vehicle in time domain), the frequency analysis (identification of the parameters of the crash pulse in frequency domain), and the time-frequency analysis, which comprises those techniques that study a signal in both the time and frequency domains simultaneously, using Morlet wavelet properties. The frequency components of the recorded crash pulse are identified by determining the ridge of the wavelet coefficients matrix. Having knowledge of the natural frequency of the signal, the damping factor for a given mode shape of the signal is estimated. In this work the major frequencies of the crash pulse are determined and the damping factor for the major mode shape is identified. The comparative analysis between the current method's outcome, the response of a model established previously by using different approach and the behavior of a real car is performed and reliability of the actual methods and tools is evaluated.
CONSTRUCTION OF SELF-DUAL RADICAL 2-CODES OF GIVEN DISTANCE
Authors: HANNUSCH CAROLIN , LAKATOS PIROSKA
Published: September 2012

We prove that for arbitrary n ∈ ℕ and [Formula: see text] and for a field K of characteristic 2 there exists an abelian group G of order 2n such that one of the powers of the radical of the group algebra K[G] is a (2n, 2n-1, 2d)-self-dual code. These codes are constructed for abelian groups G with decomposition [Formula: see text] where a1 ≥ 3 and si ≥ 0(1 ≤ i ≤ 3).
ON mRJ REACHABILITY IN TREES
Authors: DEB BISWAJIT , KAPOOR KALPESH , PATI SUKANTA
Published: September 2012

Given a tree T, a configuration of T is denoted by [Formula: see text] which represents that there is a robot at the vertex u, a hole at the vertex v and obstacles in the remaining vertices of T. By an mRJ move we mean that the robot is moved from the vertex u to a vertex v having a hole by jumping over m obstacles along a path. The case m = 0 is a simple move of taking the robot from u to the adjacent vertex v with a hole. We investigate the problem of moving a robot from its initial position to all the other vertices using mRJ moves (for some fixed m) in addition to simple moves. A tree is said to be mRJ reachable if there exists a configuration from which it is possible to take the robot to any vertex of the tree using simple or mRJ moves. A connected graph is 1RJ reachable. However, for m ≥ 2 there exists graphs that are not mRJ reachable. We characterize 2RJ and 3RJ reachable trees and give bound for the diameter of mRJ reachable trees.
WILDSENSING
Authors: Dyo Vladimir , Ellwood Stephen A. , Macdonald David W. , Markham Andrew , Trigoni Niki , Wohlers Ricklef , Mascolo Cecilia , Pásztor Bence , Scellato Salvatore , Yousef Kharsim
Published: September 2012

The increasing adoption of wireless sensor network technology in a variety of applications, from agricultural to volcanic monitoring, has demonstrated their ability to gather data with unprecedented sensing capabilities and deliver it to a remote user. However, a key issue remains how to maintain these sensor network deployments over increasingly prolonged deployments. In this article, we present the challenges that were faced in maintaining continual operation of an automated wildlife monitoring system over a one-year period. This system analyzed the social colocation patterns of European badgers (
Meles meles
) residing in a dense woodland environment using a hybrid RFID-WSN approach. We describe the stages of the evolutionary development, from implementation, deployment, and testing, to various iterations of software optimization, followed by hardware enhancements, which in turn triggered the need for further software optimization. We highlight the main lessons learned: the need to factor in the maintenance costs while designing the system; to consider carefully software and hardware interactions; the importance of rapid prototyping for initial deployment (this was key to our success); and the need for continuous interaction with domain scientists which allows for unexpected optimizations.
AutoWitness
Authors: Guha Santanu , Plarre Kurt , Lissner Daniel , Mitra Somnath , Krishna Bhagavathy , Dutta Prabal , Kumar Santosh
Published: September 2012

We present AutoWitness, a system to deter, detect, and track personal property theft, improve historically dismal stolen property recovery rates, and disrupt stolen property distribution networks. A property owner embeds a small tag inside the asset to be protected, where the tag lies dormant until it detects vehicular movement. Once moved, the tag uses inertial sensor-based dead reckoning to estimate position changes, but to reduce integration errors, the relative position is reset whenever the sensors indicate the vehicle has stopped. The sequence of movements, stops, and turns are logged in compact form and eventually transferred to a server using a cellular modem after both sufficient time has passed (to avoid detection) and RF power is detectable (hinting cellular access may be available). Eventually, the trajectory data are sent to a server which attempts to match a path to the observations. The algorithm uses a Hidden Markov Model of city streets and Viterbi decoding to estimate the most likely path. The proposed design leverages low-power radios and inertial sensors, is immune to intransit cloaking, and supports post hoc path reconstruction. Our prototype demonstrates technical viability of the design; the volume market forces driving machine-to-machine communications will soon make the design economically viable.
A novel framework for energy-efficient data gathering with random coverage in wireless sensor networks
Authors: Choi Wook , Ghidini Giacomo , Das Sajal K.
Published: September 2012

In wireless sensor networks, different applications feature different requirements in terms of such performance metrics as sensing coverage and data reporting latency. In most applications, it is usually sufficient to provide a
Desired Sensing Coverage
(DSC) lower than full coverage at any instance with the guarantee that the whole area will eventually be covered within a specified delay bound. Due to the fact that these applications are also expected to run for longer periods of time and at the same time battery recharging and replacement are costly, energy consumption in wireless sensor networks should be minimized while achieving the application goals. In this article, we propose a novel framework for application-specific data gathering which exploits a trade-off between coverage and latency, thereby minimizing energy consumption and extending the network lifetime. The proposed energy-efficient, constant-time, randomized scheme, called
Coverage-Adaptive raNdom SEnsor sElection
(CANSEE), selects a subset of
k
sensors to report at each round so as to fulfill the application-specific requirement of desired sensing coverage and bounded latency, instead of always guaranteeing full coverage and minimum latency. We present a probabilistic model to estimate: (i) the connectivity of those selected
k
sensors and the number of additional sensors needed to guarantee connectivity; (ii) a lower bound on
k
in each round; and (iii) the probability of almost surely having
k
data reporters using the Chernoff bound. The immediate event detection capability achieved by the proposed CANSEE scheme is also analyzed to compare the performance of our framework with other data gathering schemes that allow 100% coverage. Simulation results demonstrate that our framework leads to a significant conservation of energy (and thus extended network lifetime) with a small trade-off between coverage and data reporting latency, yet providing the required data reporting capability.
Online privacy; replicating research results
Authors: Reed Daniel , Chi Ed H.
Published: September 2012

The
Communications
Web site, http://cacm.acm.org, features more than a dozen bloggers in the BLOG@CACM community. In each issue of
Communications
, we'll publish selected posts or excerpts.

twitter

Follow us on Twitter at http://twitter.com/blogCACM

http://cacm.acm.org/blogs/blog-cacm

Daniel Reed offers three ideas about the future of personal online information management. Ed H. Chi writes about replication of experiments and how experiments are often the beginning, rather than the end, of a scientific inquiry.
SP4
Authors: Gill Harjot , Lin Dong , Sarna Lohit , Mead Robert , Lee Kenton C.T. , Loo Boon Thau
Published: September 2012

We propose the demonstration of SP4, a software-based programmable packet processing platform that supports (1) stateful packet processing useful for analyzing traffic flows with session semantics, (2) uses a task-stealing architecture that automatically leverages multi-core processing capabilities in a load-balanced manner without the need for explicit performance profiling, and (3) a declarative language for rapidly specifying and composing new packet processing functionalities from reusable modules. Our demonstration showcases the use of SP4 for performing high-throughput analysis of traffic traces for a variety of applications, such as filtering out unwanted traffic and detection of DDoS attacks using machine learning based analysis.
Reviving delay-based TCP for data centers
Authors: Lee Changhyun , Jang Keon , Moon Sue
Published: September 2012

With the rapid growth of data centers, minimizing the queueing delay at network switches has been one of the key challenges. In this work, we analyze the shortcomings of the current TCP algorithm when used in data center networks, and we propose to use latency-based congestion detection and rate-based transfer to achieve ultra-low queueing delay in data centers.
The only constant is change
Authors: Xie Di , Ding Ning , Hu Y. Charlie , Kompella Ramana
Published: September 2012

In multi-tenant datacenters, jobs of different tenants compete for the shared datacenter network and can suffer poor performance and high cost from varying, unpredictable network performance. Recently, several virtual network abstractions have been proposed to provide explicit APIs for tenant jobs to specify and reserve virtual clusters (VC) with both explicit VMs and required network bandwidth between the VMs. However, all of the existing proposals reserve a fixed bandwidth throughout the entire execution of a job.

In the paper, we first profile the traffic patterns of several popular cloud applications, and find that they generate substantial traffic during only 30%-60% of the entire execution, suggesting existing simple VC models waste precious networking resources. We then propose a fine-grained virtual network abstraction, Time-Interleaved Virtual Clusters (TIVC), that models the time-varying nature of the networking requirement of cloud applications. To demonstrate the effectiveness of TIVC, we develop Proteus, a system that implements the new abstraction. Using large-scale simulations of cloud application workloads and prototype implementation running actual cloud applications, we show the new abstraction significantly increases the utilization of the entire datacenter and reduces the cost to the tenants, compared to previous fixed-bandwidth abstractions.
CarSpeak
Authors: Kumar Swarun , Shi Lixin , Ahmed Nabeel , Gil Stephanie , Katabi Dina , Rus Daniela
Published: September 2012

This paper introduces CarSpeak, a communication system for autonomous driving. CarSpeak enables a car to query and access sensory information captured by other cars in a manner similar to how it accesses information from its local sensors. CarSpeak adopts a content-centric approach where information objects -- i.e., regions along the road -- are first class citizens. It names and accesses road regions using a multi-resolution system, which allows it to scale the amount of transmitted data with the available bandwidth. CarSpeak also changes the MAC protocol so that, instead of having nodes contend for the medium, contention is between road regions, and the medium share assigned to any region depends on the number of cars interested in that region.

CarSpeak is implemented in a state-of-the-art autonomous driving system and tested on indoor and outdoor hardware testbeds including an autonomous golf car and 10 iRobot Create robots. In comparison with a baseline that directly uses 802.11, CarSpeak reduces the time for navigating around obstacles by 2.4x, and reduces the probability of a collision due to limited visibility by 14x.
Demo
Authors: Suresh Lalith , Schulz-Zander Julius , Merz Ruben , Feldmann Anja
Published: September 2012

We present a demo of Odin, an SDN framework to program enterprise wireless local area networks (WLANs). Enterprise WLANs need to support a wide range of services and functionalities. This includes authentication, authorization and accounting, policy, mobility and interference management, and load balancing. WLANs also exhibit unique challenges. In particular, access point (AP) association decisions are not made by the infrastructure, but by clients. In addition, the association state machine combined with the broadcast nature of the wireless medium requires keeping track of a large amount of state changes. To this end, Odin builds on a light virtual AP abstraction that greatly simplifies client management. Odin does not require any client side modifications and its design supports WPA2 Enterprise. With Odin, a network operator can implement enterprise WLAN services as network applications.
A smart pre-classifier to reduce power consumption of TCAMs for multi-dimensional packet classification
Authors: Ma Yadi , Banerjee Suman
Published: September 2012

Ternary Content-Addressable Memories (TCAMs) has become the industrial standard for high-throughput packet classification. However, one major drawback of TCAMs is their high power consumption, which is becoming critical with the boom of data centers, the growing classifiers and the deployment of IPv6. In this paper, we propose a practical and efficient solution which introduces a smart pre-classifier to reduce power consumption of TCAMs for multi-dimensional packet classification. We reduce the dimension of the problem through the pre-classifier which pre-classifies a packet on two header fields, source and destination IP addresses. We then return to the high dimension problem where only a small portion of a TCAM is activated and searched for a given packet. The smart pre-classifier is built in a way such that a given packet matches at most one entry in the pre-classifier, which make commodity TCAMs sufficient to implement the pre-classifier. Furthermore, each rule is stored only once in one of the TCAM blocks, which avoids rule replication. The presented solution uses commodity TCAMs, and the proposed algorithms are easy to implement. Our scheme achieves a median power reduction of 91% and an average power reduction of 88% on real and synthetic classifiers respectively.
ShadowStream
Authors: Tian Chen , Alimi Richard , Yang Yang Richard , Zhang David
Published: September 2012

As live streaming networks grow in scale and complexity, they are becoming increasingly difficult to evaluate. Existing evaluation methods including lab/testbed testing, simulation, and theoretical modeling, lack either scale or realism. The industrial practice of gradually-rolling-out in a testing channel is lacking in controllability and protection when experimental algorithms fail, due to its passive approach. In this paper, we design a novel system called ShadowStream that introduces evaluation as a built-in capability in production Internet live streaming networks. ShadowStream introduces a simple, novel, transparent embedding of experimental live streaming algorithms to achieve safe evaluations of the algorithms during large-scale, real production live streaming, despite the possibility of large performance failures of the tested algorithms. ShadowStream also introduces transparent, scalable, distributed experiment orchestration to resolve the mismatch between desired viewer behaviors and actual production viewer behaviors, achieving experimental scenario controllability. We implement ShadowStream based on a major Internet live streaming network, build additional evaluation tools such as deterministic replay, and demonstrate the benefits of ShadowStream through extensive evaluations.
Deletion of Rab GAP AS160 modifies glucose uptake and GLUT4 translocation in primary skeletal muscles and adipocytes and impairs glucose homeostasis
Authors: Lansey Melissa N. , Walker Natalie N. , Hargett Stefan R. , Stevens Joseph R. , Keller Susanna R.
Published: September 2012

Tight control of glucose uptake in skeletal muscles and adipocytes is crucial to glucose homeostasis and is mediated by regulating glucose transporter GLUT4 subcellular distribution. In cultured cells, Rab GAP AS160 controls GLUT4 intracellular retention and release to the cell surface and consequently regulates glucose uptake into cells. To determine AS160 function in GLUT4 trafficking in primary skeletal muscles and adipocytes and investigate its role in glucose homeostasis, we characterized AS160 knockout (AS160−/−) mice. We observed increased and normal basal glucose uptake in isolated AS160−/−adipocytes and soleus, respectively, while insulin-stimulated glucose uptake was impaired and GLUT4 expression decreased in both. No such abnormalities were found in isolated AS160−/−extensor digitorum longus muscles. In plasma membranes isolated from AS160−/−adipose tissue and gastrocnemius/quadriceps, relative GLUT4 levels were increased under basal conditions and remained the same after insulin treatment. Concomitantly, relative levels of cell surface-exposed GLUT4, determined with a glucose transporter photoaffinity label, were increased in AS160−/−adipocytes and normal in AS160−/−soleus under basal conditions. Insulin augmented cell surface-exposed GLUT4 in both. These observations suggest that AS160 is essential for GLUT4 intracellular retention and regulation of glucose uptake in adipocytes and skeletal muscles in which it is normally expressed. In vivo studies revealed impaired insulin tolerance in the presence of normal (male) and impaired (female) glucose tolerance. Concurrently, insulin-elicited increases in glucose disposal were abolished in all AS160−/−skeletal muscles and liver but not in AS160−/−adipose tissues. This suggests AS160 as a target for differential manipulation of glucose homeostasis.
Detection ofSalmonellaspp.,Candida albicans,Aspergillusspp., and Antimicrobial Residues in Raw and Processed Cow Milk from Selected Smallholder Farms of Zimbabwe
Authors: Mhone Tryness Anastazia , Matope Gift , Saidi Petronella Tapiwa
Published: September 2012

A cross-sectional study was conducted to detect the presence ofSalmonellaspp.,Candida albicans,Aspergillusspp., and antimicrobial residues in raw milk (n=120) and processed cow milk (n=20) from smallholder dairy farms from three sites in Zimbabwe. Culture and isolation ofSalmonellaspp.,C. albicans, andAspergillusspp. were performed using selective media, while antimicrobial residues were detected by a dye reduction test. NoSalmonella, butC. albicans(17.5%; 21/120),Aspergillusspp. (0.8%; 1/120), and antimicrobial residues (2.5%; 3/120) were detected from raw milk.C. albicanswas isolated from all three sites, whileAspergillusspp. and antimicrobial residues were detected from sites 1 and 3, respectively. From processed milk, onlyC. albicans(5%) was isolated whileAspergillusspp. and antimicrobial residues were not detected. These results suggested low prevalence ofSalmonellaspp. andAspergillusspp. and a relatively high prevalence ofC. albicansin raw milk from the smallholder farms. The potential public health risks ofC. albicansand the detected antimicrobial residues need to be considered. Thus, educating farmers on improving milking hygiene and storage of milk and establishing programmes for monitoring antimicrobial residues may help to improve the safety of milk from smallholder farms.
Leading from the Middle: Replication of a Re-Engagement Program for Veterans with Mental Disorders Lost to Follow-Up Care
Authors: Goodrich David E. , Bowersox Nicholas W. , Abraham Kristen M. , Burk Jeffrey P. , Visnic Stephanie , Lai Zongshan , Kilbourne Amy M.
Published: September 2012

Objectives. Persons with mental disorders experience functional impairments and premature mortality. Limited continuity of care may contribute to disparities in this group. We describe the replication of an evidence-based outreach program (Re-Engage) to reconnect Veterans with mental disorders into care who have dropped out of services.Methods. Using the Enhanced Replicating Effective Programs framework, population-based registries were used to identify Veterans lost-to-care, and providers used this information to determine Veteran disposition and need for care. Providers recorded Veteran preferences, health status, and care utilization, and formative process data was collected to document implementation efforts.Results. Among Veterans who dropped out of care(n=126), the mean age was 49 years, 10% were women, and 29% were African-American. Providers determined that 39% of Veterans identified for re-engagement were deceased, hospitalized, or ineligible for care. Of the remaining 68 Veterans, outreach efforts resulted in contact with 20, with 7 returning to care. Providers averaged 14.2 hours over 4 months conducting re-engagement services and reported that gaining facility leadership support and having service agreements for referrals were essential for program implementation.Conclusions. Population-level, panel management strategies to re-engage Veterans with mental disorders are potentially feasible if practices are identified to facilitate national rollout.
Pediatric Influenza-Associated Deaths in New York State: Death Certificate Coding and Comparison to Laboratory-Confirmed Deaths
Authors: Hoefer Dina , Cherry Bryan , Kacica Marilyn , McClamroch Kristi , Kilby Kimberly
Published: September 2012

Introduction. Surveillance for laboratory-confirmed influenza-associated deaths in children is used to monitor the severity of influenza at the population level and to inform influenza prevention and control policies. The goal of this study was to better estimate pediatric influenza mortality in New York state (NYS). Methods. Death certificate data were requested for all passively reported deaths and any pneumonia and influenza (P&I) coded pediatric deaths occurring between October 2004 and April 2010, excluding New York City (NYC) residents. A matching algorithm and capture-recapture analysis were used to estimate the total number of influenza-associated deaths among NYS children. Results. Thirty-four laboratory-confirmed influenza-associated pediatric deaths were reported and 67 death certificates had a P&I coded death; 16 deaths matched. No laboratory-confirmed influenza-associated death had a pneumonia code and no pneumonia coded deaths had laboratory evidence of influenza infection in their medical record. The capture-recapture analysis estimated between 38 and 126 influenza-associated pediatric deaths occurred in NYS during the study period. Conclusion. Passive surveillance for influenza-associated deaths continues to be the gold standard methodology for characterizing influenza mortality in children. Review of death certificates can complement but not replace passive reporting, by providing better estimates and detecting any missed laboratory-confirmed deaths.
RIT with Y90-Ibritumomab Tiuxetan in Follicular Non-Hodgkin Lymphoma: Evaluation of Recent Outcomes in a Single Institution
Authors: Andrade Campos Marcio Miguel , Montes Limón Anel E. , Grasa Jose María , Lievano Paola , Baringo Teresa , Giraldo Pilar
Published: September 2012

Background. Based on historical data we reviewed our hospital clinical database to analyse our updated information and therapy outcomes of follicular non-Hodgkin lymphoma (F-NHL) patients treated with90Y-Ibritumomab tiuxetan.Patients and Methods. Between 2005 and 2011, 56 F-NHL patients were included in a clinical protocol conducted by a multidisciplinary team and treated in the same centre. All patients received 0.3 or 0.4 mCi/kg IV (88%) of90Y-IT; response evaluation was performed 12 weeks after.Results. M/F 44.6%/55.4%, mean age 61.45 years (30–85); ECOG 0-1 96.9%. According to FLIPI score, distribution were good: 58.5%, intermediate: 29.2%, and poor: 12.3%. Previous therapies: >2: 40% (26). ORR was 94.6% (53/56). CR: 85.7%; CR according to previous disease: relapsed disease: 90% (27/30), refractory disease: 42.85% (3/7), consolidation with CR: 92.85% (13/14), and consolidation with PR: 100% (5/5). Global PR and NR were 8.9% (5) and 5.3% (3), respectively. Mean OS 63.86 months with a mean follow-up time of 57 months (2–73). Mean TTP: 52.65 months (95% CI: 43.83–61.48). Median OS and TTP were not achieved. No hospital submissions or deaths were registered.Conclusions. This study confirms the safety and high efficacy of90Y-IT in F-NHL patients, RIT in early stage of disease could improve outcomes.
Clinical Studies on Treatment of Earthquake-Caused Posttraumatic Stress Disorder Using Electroacupuncture
Authors: Wang Yu , Hu You-ping , Wang Wen-chun , Pang Ri-zhao , Zhang An-ren
Published: September 2012

The objective of this study was to assess the efficacy and safety of electroacupuncture in 138 patients with earthquake-caused PTSD using Randomized Controlled Trials (RCTs). 138 cases enrolled were randomly assigned to an electro-acupuncture group and a paroxetine group. The electro-acupuncture group was treated by scalp electro-acupuncture on Baihui (GV 20), Sishencong (EX-HN 1), Shenting (GV 24), and Fengchi (GB 20), and the paroxetine group was treated with simple oral administration of paroxetine. The efficacy and safety of the electro-acupuncture on treatment of 69 PTSD patients were evaluated using Clinician-Administered PTSD Scale (CAPS), Hamilton Depression Scale (HAMD), Hamilton Anxiety Scale (HAMA), and Treatment Emergent Symptom Scale (TESS) according to clinical data. The total scores of CAPS, HAMD, and HAMA in the two groups after treatment showed significant efficacy compared to those before treatment. The comparison of reduction in the scores of CAPS, HAMD, and HAMA between the two groups suggested that the efficacy in the treated group was better than that in the paroxetine group. The present study suggested that the electro-acupuncture and paroxetine groups have significant changes in test PTSD, but the electro-acupuncture 2 group was more significant.