bluuebunny/crossref_metadata_2025 huggingface dataset:
Mutations in the Pseudomonas aeruginosa Needle Protein Gene
pscF
Confer Resistance to Phenoxyacetamide Inhibitors of the Type III Secretion System
Authors: Bowlin Nicholas O. , Williams John D. , Knoten Claire A. , Torhan Matthew C. , Tashjian Tommy F. , Li Bing , Aiello Daniel , Mecsas Joan , Hauser Alan R. , Peet Norton P. , Bowlin Terry L. , Moir Donald T.
Published: January 2014

The type III secretion system (T3SS) is a clinically important virulence mechanism in
Pseudomonas aeruginosa
that secretes and translocates effector toxins into host cells, impeding the host's rapid innate immune response to infection. Inhibitors of T3SS may be useful as prophylactic or adjunctive therapeutic agents to augment the activity of antibiotics in
P. aeruginosa
infections, such as pneumonia and bacteremia. One such inhibitor, the phenoxyacetamide MBX 1641, exhibits very responsive structure-activity relationships, including striking stereoselectivity, in its inhibition of
P. aeruginosa
T3SS. These features suggest interaction with a specific, but unknown, protein target. Here, we identify the apparent molecular target by isolating inhibitor-resistant mutants and mapping the mutation sites by deep sequencing. Selection and sequencing of four independent mutants resistant to the phenoxyacetamide inhibitor MBX 2359 identified the T3SS gene
pscF
, encoding the needle apparatus, as the only locus of mutations common to all four strains. Transfer of the wild-type and mutated alleles of
pscF
, together with its chaperone and cochaperone genes
pscE
and
pscG
, to a Δ
pscF P. aeruginosa
strain demonstrated that each of the single-codon mutations in
pscF
is necessary and sufficient to provide secretion and translocation that is resistant to a variety of phenoxyacetamide inhibitor analogs but not to T3SS inhibitors with different chemical scaffolds. These results implicate the PscF needle protein as an apparent new molecular target for T3SS inhibitor discovery and suggest that three other chemically distinct T3SS inhibitors interact with one or more different targets or a different region of PscF.
Comparative Analyses of a Cystic Fibrosis Isolate of Bordetella bronchiseptica Reveal Differences in Important Pathogenic Phenotypes
Authors: Sukumar Neelima , Nicholson Tracy L. , Conover Matt S. , Ganguly Tridib , Deora Rajendar
Published: January 2014

Bordetella bronchiseptica
is a Gram-negative bacterium that infects and causes disease in a wide variety of animals.
B. bronchiseptica
also infects humans, thereby demonstrating zoonotic transmission. An extensive characterization of human
B. bronchiseptica
isolates is needed to better understand the distinct genetic and phenotypic traits associated with these zoonotic transmission events. Using whole-genome transcriptome and CGH analysis, we report that a
B. bronchiseptica
cystic fibrosis isolate, T44625, contains a distinct genomic content of virulence-associated genes and differentially expresses these genes compared to the sequenced model laboratory strain RB50, a rabbit isolate. The differential gene expression pattern correlated with unique phenotypes exhibited by T44625, which included lower motility, increased aggregation, hyperbiofilm formation, and an increased
in vitro
capacity to adhere to respiratory epithelial cells. Using a mouse intranasal infection model, we found that although defective in establishing high bacterial burdens early during the infection process, T44625 persisted efficiently in the mouse nose. By documenting the unique genomic and phenotypic attributes of T44625, this report provides a blueprint for understanding the successful zoonotic potential of
B. bronchiseptica
and other zoonotic bacteria.
MELAS, an important consideration in the adult population presenting with unusual and recurrent stroke-like episodes
Authors: Corr Alison , Gaughan Maria , Moroney Joan , Looby Seamus
Published: January 2014

A 48-year-old man was admitted for workup of stroke-like symptoms and generalised tonic–clonic seizures. History and examination revealed that the patient had background diagnoses of type 2 diabetes mellitus, epilepsy and had suffered a temporal lobe infarct 3 years ago. The unusual presentation and physical findings, along with subsequent MRI findings led to a diagnosis of mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS). MELAS is a mitochondrial disorder typified by the aforementioned symptoms, and is typically diagnosed in the first two decades of life.
The ‘hidden’ SAPHO syndrome
Authors: Carr Frances
Published: January 2014

A 64-year-old woman presented to our clinic with a 4-year history of cognitive decline. The clinical examination revealed an incidental finding of the ‘SAPHO’ (Synovitis Acne Pustulosis Hyperostosis Osteitis) syndrome which was subsequently confirmed by diagnostic imaging. Owing to her classical presentation and her asymptomatic status she was managed conservatively with observation without any complication.
An uncommon complication of acute stroke thrombolysis
Authors: Allan Morven , Zachariah George , Kordzadeh Ali , Umachandran Velaitham
Published: January 2014

Thrombolysis with tissue plasminogen activator is a well-established treatment for acute ischaemic stroke. We report a case of an 87-year-old woman who developed an acute ischaemic limb, on the background of stroke thrombolysis, and underwent an embolectomy. A rare but serious complication, there are few reports of similar thromboembolic events, particularly in patients with known atrial fibrillation as presented in this case. Early recognition of this rare complication may prevent long-term, and at times fatal, complications.
Difficult to wean: think of the diaphragm
Authors: Suryanarayana Jandhyala , Varma Muralidhar , Vidyasagar Sudha , Vivek Ganapathiraman
Published: January 2014

A 65-year-old woman, treated for non-ST segment elevation myocardial infarction and unexplained type 2 respiratory failure, was referred to our hospital in view of difficulty in weaning off the ventilator. She was evaluated in detail for persistent hypercapnia. Ultrasound of the diaphragm showed minimal excursion of diaphragm while she was off the ventilator and fluoroscopy confirmed bilateral diaphragmatic palsy. As extensive radiological, immunological and microbiological workup ruled out other possible aetiologies, a diagnosis of idiopathic Bell's palsy of the diaphragm was made. She was treated with valacyclovir and steroids after which she gradually recovered and was weaned off the ventilator.
Implementation of an App-based neuromuscular training programme to prevent ankle sprains: a process evaluation using the RE-AIM Framework
Authors: Vriend Ingrid , Coehoorn Iris , Verhagen Evert
Published: January 2014

Background/aim

The contemporary electronic media is regarded as a practical tool in the dissemination of preventive measures and interventions. For this purpose an App (free of charge) was developed including an efficacious programme for the prevention of ankle sprain recurrences. This study evaluated the implementation effectiveness of this ‘Versterk je Enkel’ App.

Methods

The App was evaluated within its practical context using the Reach Effectiveness Adoption Implementation Maintenance (RE-AIM) Framework. The launch of the App was accompanied by a press release, website banners, as well as online and offline advertisements. Data for the evaluation of the App were objectively registered through Google analytics. Data were obtained in February 2013 based on 25 781 users resulting in follow-ups of 18 months (iOS version) and 15 months (Android version), respectively. Users questionnaires provided a qualitative view of the objectively assessed measures (n=82) to gain insight into the demographics of users, reasons to download, user experience and how the information was used.

Results

The App reached only 2.6% of the projected target population. User ratings for the App's relevancy, clarity, usefulness, appeal, information and reliability were high. App usage indicates that compliance with the embedded programme was low.

Conclusions

Although the App was well received by the users, targeted efforts are required to ensure proper uptake and usage of the App by the target population. This also holds true for eHealth and mHealth efforts aimed at athlete care and injury prevention in general.
Using quality improvement to optimise paediatric discharge efficiency
Authors: White Christine M , Statile Angela M , White Denise L , Elkeeb Dena , Tucker Karen , Herzog Diane , Warrick Stephen D , Warrick Denise M , Hausfeld Julie , Schondelmeyer Amanda , Schoettker Pamela J , Kiessling Pamela , Farrell Michael , Kotagal Uma , Ryckman Frederick C
Published: January 2014

Background

Bed capacity management is a critical issue facing hospital administrators, and inefficient discharges impact patient flow throughout the hospital. National recommendations include a focus on providing care that is timely and efficient, but a lack of standardised discharge criteria at our institution contributed to unpredictable discharge timing and lengthy delays. Our objective was to increase the percentage of Hospital Medicine patients discharged within 2 h of meeting criteria from 42% to 80%.

Methods

A multidisciplinary team collaborated to develop medically appropriate discharge criteria for 11 common inpatient diagnoses. Discharge criteria were embedded into electronic medical record (EMR) order sets at admission and could be modified throughout a patient's stay. Nurses placed an EMR time-stamp to signal when patients met all discharge goals. Strategies to improve discharge timeliness emphasised completion of discharge tasks prior to meeting criteria. Interventions focused on buy-in from key team members, pharmacy process redesign, subspecialty consult timeliness and feedback to frontline staff. A P statistical process control chart assessed the impact of interventions over time. Length of stay (LOS) and readmission rates before and after implementation of process measures were compared using the Wilcoxon rank-sum test.

Results

The percentage of patients discharged within 2 h significantly improved from 42% to 80% within 18 months. Patients studied had a decrease in median overall LOS (from 1.56 to 1.44 days; p=0.01), without an increase in readmission rates (4.60% to 4.21%; p=0.24). The 12-month rolling average census for the study units increased from 36.4 to 42.9, representing an 18% increase in occupancy.

Conclusions

Through standardising discharge goals and implementation of high-reliability interventions, we reduced LOS without increasing readmission rates.
Anticolorectal cancer activity of the omega-3 polyunsaturated fatty acid eicosapentaenoic acid
Authors: Cockbain Andrew J , Volpato Milene , Race Amanda D , Munarini Alessandra , Fazio Chiara , Belluzzi Andrea , Loadman Paul M , Toogood Giles J , Hull Mark A
Published: January 2014

Background

Oral administration of the omega-3 fatty acid eicosapentaenoic acid (EPA), as the free fatty acid (FFA), leads to EPA incorporation into, and reduced growth of, experimental colorectal cancer liver metastases (CRCLM).

Design:

We performed a Phase II double-blind, randomised, placebo-controlled trial of EPA-FFA 2 g daily in patients undergoing liver resection surgery for CRCLM. The patients took EPA-FFA (n=43) or placebo (n=45) prior to surgery. The primary end-point was the CRCLM Ki67 proliferation index (PI). Secondary end-points included safety and tolerability of EPA-FFA, tumour fatty acid content and CD31-positive vascularity. We also analysed overall survival (OS) and disease-free survival (DFS).

Results

The median (range) duration of EPA-FFA treatment was 30 (12–65) days. Treatment groups were well matched with no significant difference in disease burden at surgery or preoperative chemotherapy. EPA-FFA treatment was well tolerated with no excess of postoperative complications. Tumour tissue from EPA-FFA-treated patients demonstrated a 40% increase in EPA content (p=0.0008), no difference in Ki67 PI, but reduced vascularity in ‘EPA-naïve’ individuals (p=0.075). EPA-FFA also demonstrated antiangiogenic activity in vitro. In the first 18 months after CRCLM resection, EPA-FFA-treated individuals obtained OS benefit compared with placebo, although early CRC recurrence rates were similar.

Conclusions

EPA-FFA therapy is safe and well tolerated in patients with advanced CRC undergoing liver surgery. EPA-FFA may have antiangiogenic properties. Remarkably, limited preoperative treatment may provide postoperative OS benefit. Phase III clinical evaluation of prolonged EPA-FFA treatment in CRCLM patients is warranted.

Trial Identifier:

ClinicalTrials.govNCT01070355.
Mitochondria: a multimodal hub of hypoxia tolerance
Authors: Pamenter Matthew E.
Published: January 2014

Decreased oxygen availability impairs cellular energy production and, without a coordinated and matched decrease in energy consumption, cellular and whole organism death rapidly ensues. Of particular interest are mechanisms that protect brain from low oxygen injury, as this organ is not only the most sensitive to hypoxia, but must also remain active and functional during low oxygen stress. As a result of natural selective pressures, some species have evolved molecular and physiological mechanisms to tolerate prolonged hypoxia with no apparent detriment. Among these mechanisms are a handful of responses that are essential for hypoxia tolerance, including (i) sensors that detect changes in oxygen availability and initiate protective responses; (ii) mechanisms of energy conservation; (iii) maintenance of basic brain function; and (iv) avoidance of catastrophic cell death cascades. As the study of hypoxia-tolerant brain progresses, it is becoming increasingly apparent that mitochondria play a central role in regulating all of these critical mechanisms. Furthermore, modulation of mitochondrial function to mimic endogenous neuroprotective mechanisms found in hypoxia-tolerant species confers protection against otherwise lethal hypoxic stresses in hypoxia-intolerant organs and organisms. Therefore, lessons gleaned from the investigation of endogenous mechanisms of hypoxia tolerance in hypoxia-tolerant organisms may provide insight into clinical pathologies related to low oxygen stress.
Efficacy Comparison of Korean Ginseng and American Ginseng on Body Temperature and Metabolic Parameters
Authors: Park Eun-Young , Kim Mi-Hwi , Kim Eung-Hwi , Lee Eun-Kyu , Park In-Sun , Yang Duck-Choon , Jun Hee-Sook
Published: January 2014

Ginseng has beneficial effects in cancer, diabetes and aging. There are two main varieties of ginseng: Panax ginseng (Korean ginseng) and Panax quinquefolius (American ginseng). There are anecdotal reports that American ginseng helps reduce body temperature, whereas Korean ginseng improves blood circulation and increases body temperature; however, their respective effects on body temperature and metabolic parameters have not been studied. We investigated body temperature and metabolic parameters in mice using a metabolic cage. After administering ginseng extracts acutely (single dose of 1000 mg/kg) or chronically (200 mg/kg/day for four weeks), core body temperature, food intake, oxygen consumption and activity were measured, as well as serum levels of pyrogen-related factors and mRNA expression of metabolic genes. Acute treatment with American ginseng reduced body temperature compared with PBS-treated mice during the night; however, there was no significant effect of ginseng treatment on body temperature after four weeks of treatment. VO 2, VCO 2, food intake, activity and energy expenditure were unchanged after both acute and chronic ginseng treatment compared with PBS treatment. In acutely treated mice, serum thyroxin levels were reduced by red and American ginseng, and the serum prostaglandin E2 level was reduced by American ginseng. In chronically treated mice, red and white ginseng reduced thyroxin levels. We conclude that Korean ginseng does not stimulate metabolism in mice, whereas a high dose of American ginseng may reduce night-time body temperature and pyrogen-related factors.
Effects of Furanodiene on 95-D Lung Cancer Cells: Apoptosis, Autophagy and G1 Phase Cell Cycle Arrest
Authors: Xu Wen-Shan , Li Ting , Wu Guo-Sheng , Dang Yuan-Ye , Hao Wen-Hui , Chen Xiu-Ping , Lu Jin-Jian , Wang Yi-Tao
Published: January 2014

Furanodiene (FUR) is a natural terpenoid isolated from Rhizoma Curcumae, a well-known Chinese medicinal herb that presents anti-proliferative activities in several cancer cell lines. Herein, we systematically investigated the effects of FUR on the significant processes of tumor progression with the relatively low concentrations in 95-D lung cancer cells. FUR concentration-dependently inhibited cell proliferation and blocked the cell cycle progressions in G1 phase by down-regulating the protein levels of cyclin D1 and CDK6, and up-regulating those of p21 and p27 in 95-D cells. FUR also affected the signaling molecules that regulate apoptosis in 95-D cells revealed by the down-regulation of the protein levels of full PARP, pro-caspase-7, survivin, and Bcl-2, and the up-regulation of cleaved PARP. Further studies showed that FUR enhanced the expression of light chain 3-II (LC3-II) in the protein level, indicating that autophagy is involved in this process. Besides, the adhesion ability of 95-D cells to matrigel and fibronectin was slightly inhibited after FUR treatment for 1 h in our experimental condition. FUR also slightly suppressed cell migration and invasion in 95-D cells according to the data from wound healing and Transwell assays, respectively. Taken together, FUR activated the signal molecules regulating G1 cell cycle arrest, apoptosis and autophagy, while slightly affecting the key steps of cell metastasis in 95-D lung cancer cells in the relatively low concentrations.
CHARGE-CONFINING GRAVITATIONAL ELECTROVACUUM SHOCK WAVE
Authors: GUENDELMAN EDUARDO , NISSIMOV EMIL , PACHEVA SVETLANA
Published: January 2014

In previous publications, we have extensively studied spherically symmetric solutions of gravity coupled to a nonstandard type of nonlinear electrodynamics containing a square-root of the ordinary Maxwell Lagrangian (the latter is known to yield quantum chromodynamic (QCD)-like confinement in a flat spacetime). A class of these solutions describe nonstandard black holes of Reissner–Nordström–(anti-)-de Sitter type with an additional constant radial vacuum electric field, in particular, a non-asymptotically flat Reissner–Nordström-type black hole. Here, we study the ultra-relativistic boost (Lousto–Sanchez extension of Aichelburg–Sexl) limit of the latter and show that, unlike the ordinary Reissner–Nordström case, we obtain a gravitational electrovacuum shock wave as a result of the persistence of the gauge field due to the "square-root" Maxwell Lagrangian term. Next, we show that this gravitational electrovacuum shock wave confines charged test particles (both massive and massless) within a finite distance from its front.
Continuity and Change in Party Politics in Japan, Taiwan and South Korea
Authors: HSIEH John Fuh-sheng
Published: January 2014

The 2012 elections in Japan, Taiwan and South Korea exhibit both long-term trends and short-term variations in each country's political landscape. All three societies are moving towards two-party competition lately, thanks mostly to the mixed-member majoritarian system adopted for legislative elections, despite the social cleavages that provide, to varying degrees, niches for small parties. The cleavage structure coupled with the electoral system largely explains the changing political landscape in these societies.
Growing Anti-Japanese Nationalistic Sentiments in China
Authors: LYE Liang Fook , WU Dan
Published: January 2014

Anti-Japanese nationalistic sentiments in China remain a bugbear in relations between China and Japan. Japan's nationalisation of the Diaoyu Islands elicited a Chinese public response targeted at things associated with Japan. In this instance, the potent mix of the islands dispute and historical issues between the two countries unleashed a wave of anti-Japanese sentiments that brought ties to a new low. Both sides are presently making an attempt to manage their differences.
Chinese Nationalism: National Pride and Attitudes Towards Others
Authors: SHAN Wei
Published: January 2014

Public opinion surveys show that Chinese citizens generally have a high level of national pride, indicating a strong sense of national identity. This identity varies across age cohorts, education and income levels, political affiliation, etc. The impression of Japan is negative, yet the younger, the more educated and the wealthier Chinese are more likely to be positive towards Japan. More than 80% agree that peaceful negotiation is the best means to resolving international conflicts.
The Middle Class and Politics in Hong Kong since the Handover
Authors: LAU Siu-kai
Published: January 2014

Since the handover, Hong Kong's middle-class has transformed from a self-confident and complacent social group to a group stricken by anxiety and discontent. These changes have brought about middle-class radicalism, “poisoned” Hong Kong's political atmosphere, deepened government-people conflict, and aggravated social and political friction. As the middle class still has vested interests in the existing institutional arrangements, middle-class instability is not likely to result in political turmoil in post-handover Hong Kong.
Can Abenomics Reinvigorate Japan's Economy?: A Preliminary Assessment
Authors: GODO Yoshihisa
Published: January 2014

After Japanese Prime Minster Shinzo Abe launched a new economic doctrine, which is often referred to as “Abenomics,” stock prices had risen dramatically till the first half of May 2013. A May 2013 public poll showed that Abenomics had worked well. Stock prices, however, have been volatile since then. This paper investigates the contents of Abenomics and considers whether Abenomics will rescue Japanese economy from its prolonged recession.
Insights to controls on dolomitization by means of reactive transport models applied to the Benicàssim case study (Maestrat Basin, eastern Spain)
Authors: Corbella M. , Gomez-Rivas E. , Martín-Martín J. D. , Stafford S. L. , Teixell A. , Griera A. , Travé A. , Cardellach E. , Salas R.
Published: January 2014

Partially dolomitized carbonate rocks of the Middle East and North America host large hydrocarbon reserves. The origin of some of these dolomites has been attributed to a hydrothermal mechanism. The Benicàssim area (Maestrat Basin, eastern Spain) constitutes an excellent field analogue for fault-controlled stratabound hydrothermal dolomitization: dolostone geobodies are well exposed and extend over several kilometres away from seismic-scale faults. This work investigates the main controls on the formation of stratabound versus massive dolomitization in carbonate sequences by means of two-dimensional (2D) reactive transport models applied to the Benicàssim case study. Simulation results suggest that the dolomitization capacity of Mg-rich fluids reaches a maximum at temperatures around 100 °C and a minimum at 25 °C (studied temperature range: 25–150 °C). It takes of the order of hundreds of thousands to millions of years to completely dolomitize kilometre-long limestone sections, with solutions flowing laterally through strata at velocities of metres per year (m/a). Permeability differences of two orders of magnitude between layers are required to form stratabound dolomitization. The kilometre-long stratabound dolostone geobodies of Benicàssim must have formed under a regime of lateral flux greater than metres per year over about a million years. As long-term dolomitization tends to produce massive dolostone bodies not seen at Benicàssim, the dolomitizing process there must have been limited by the availability of fluid volume or the flow-driving mechanism. Reactive transport simulations have proven a useful tool to quantify aspects of the Benicàssim genetic model of hydrothermal dolomitization.
Simulating flow through forward sediment model stratigraphies: insights into climatic control of reservoir quality in isolated carbonate platforms
Authors: Whitaker F. F. , Felce G. P. , Benson G.S. , Amour F. , Mutti M. , Smart P. L.
Published: January 2014

Whilst sophisticated multiphase fluid flow models are routinely employed to understand behaviour of oil and gas reservoirs, high-resolution data describing the three-dimensional (3D) distribution of rock characteristics is rarely available to populate models. We present a new approach to developing a quantitative understanding of the effect of individual controls on the distribution of petrophysical properties and their impact on fluid flow. This involves simulating flow through high-detail permeability architectures generated by forward modelling of the coupled depositional–diagenetic evolution of isolated platforms using CARB3D
+
. This workflow is exemplified by an investigation of interactions between subsidence and climate, and their expression in spatial variations in reservoir quality in an isolated carbonate platform of similar size and subsidence history to the Triassic Latemar Platform.

Dissolutional lowering during subaerial exposure controls platform-top graininess via platform top hydrodynamics during the subsequent transgression. Dissolved carbonate is reprecipitated as cements by percolating meteoric waters. However, associated subsurface meteoric dissolution generates significant secondary porosity under a more humid climate. Slower subsidence enhances diagenetic overprinting during repeated exposure events. Single-phase streamline simulations show how early diagenesis develops more permeable fairways within the finer-grained condensed units that can act as thief zones for flow from the grainier but less diagenetically altered cyclic units.
Suffix Array Construction in External Memory Using D-Critical Substrings
Authors: Nong Ge , Chan Wai Hong , Zhang Sen , Guan Xiao Feng
Published: January 2014

We present a new suffix array construction algorithm that aims to build, in external memory, the suffix array for an input string of length
n
measured in the magnitude of tens of Giga characters over a constant or integer alphabet. The core of this algorithm is adapted from the framework of the original internal memory SA-DS algorithm that samples fixed-size d-critical substrings. This new external-memory algorithm, called EM-SA-DS, uses novel cache data structures to construct a suffix array in a sequential scanning manner with good data spatial locality: data is read from or written to disk sequentially. On the assumed external-memory model with RAM capacity
Ω
((
nB
)
0.5
), disk capacity
O
(
n
), and size of each I/O block
B
, all measured in log
n
-bit words, the I/O complexity of EM-SA-DS is
O
(
n
/
B
). This work provides a general cache-based solution that could be further exploited to develop external-memory solutions for other suffix-array-related problems, for example, computing the longest-common-prefix array, using a modern personal computer with a typical memory configuration of 4GB RAM and a single disk.
Collaborative localization in visual sensor networks
Authors: Karakaya Mahmut , Qi Hairong
Published: January 2014

Collaboration in visual sensor networks is essential not only to compensate for the limitations of each sensor node but also to tolerate inaccurate information generated by faulty sensors. This article focuses on the design of a collaborative target localization algorithm that is resilient to sensor faults. We first develop a distributed solution to fault-tolerant target localization based on a so-called
certainty map
. To tolerate potential sensor faults, a voting mechanism is adopted and a threshold value needs to be specified which is the key to the realization of the distributed solution. Analytical study is conducted to derive the lower and upper bounds for the threshold such that the probability of faulty sensors negatively impacts the localization performance is less than a small value. Second, we focus on the detection and correction of one type of sensor faults, error in camera orientation. We construct a generative image model in each camera based on the detected target location to estimate camera's orientation, detect inaccuracies in camera orientations and correct them before they cascade. Based on results obtained from both simulation and real experiments, we show that the proposed method is effective in localization accuracy as well as fault detection and correction performance.
Distributed data association in smart camera networks using belief propagation
Authors: Wan Jiuqing , Liu Li
Published: January 2014

One of the fundamental requirements for visual surveillance with smart camera networks is the correct association of camera's observations with the tracks of objects under tracking. Most of the current systems work in a centralized manner in that the observations on all cameras need to be transmitted to a central server where some data association algorithm is running. Recently some works have been shown for distributed data association based solely on appearance observation. However, how to perform distributed association inference using both appearance and spatio-temporal information is still unclear. In this article, we present a novel method for estimating the posterior distribution of the label of each observation, indicating which of the objects it comes from, based on belief propagation between neighboring cameras. We develop distributed forward and backward inference algorithms for online and offline application, respectively, and further extend the algorithms to the case of unreliable detection. We also incorporate the proposed inference algorithms into distributed EM framework to simultaneously solve the problem of data association and appearance model learning in a completely distributed manner. The proposed method is verified on artificial data and on real world observations collected by a camera networks in an office building.
Low-complexity scalable distributed multicamera tracking of humans
Authors: Gruenwedel Sebastian , Jelaca Vedran , Nino-Castaneda Jorge Oswaldo , Hese Peter van , Cauwelaert Dimitri van , Haerenborgh Dirk van , Veelaert Peter , Philips Wilfried
Published: January 2014

Real-time tracking of people has many applications in computer vision, especially in the domain of surveillance. Typically, a network of cameras is used to solve this task. However, real-time tracking remains challenging due to frequent occlusions and environmental changes. Besides, multicamera applications often require a trade-off between accuracy and communication load within a camera network. In this article, we present a real-time distributed multicamera tracking system for the analysis of people in a meeting room. One contribution of the article is that we provide a
scalable
solution using smart cameras. The system is scalable because it requires a very small communication bandwidth and only light-weight processing on a “fusion center” which produces final tracking results. The fusion center can thus be cheap and can be duplicated to increase reliability.

In the proposed decentralized system all low level video processing is performed on smart cameras. The smart cameras transmit a compact high-level description of moving people to the fusion center, which fuses this data using a Bayesian approach. A second contribution in our system is that the camera-based processing takes feedback from the fusion center about the most recent locations and motion states of tracked people into account. Based on this feedback and background subtraction results, the smart cameras generate a best hypothesis for each person.

We evaluate the performance (in terms of precision and accuracy) of the tracker in indoor and meeting scenarios where individuals are often occluded by other people and/or furniture. Experimental results are presented based on the tracking of up to 4 people in a meeting room of 9 m by 5 m using 6 cameras. In about two hours of data, our method has only 0.3 losses per minute and can typically measure the position with an accuracy of 21 cm. We compare our approach to state-of-the-art methods and show that our system performs at least as good as other methods. However, our system is capable to run in real-time and therefore produces instantaneous results.
Calibrating a wide-area camera network with non-overlapping views using mobile devices
Authors: Kuo Thomas , Ni Zefeng , Sunderrajan Santhoshkumar , Manjunath B. S.
Published: January 2014

In a wide-area camera network, cameras are often placed such that their views do not overlap. Collaborative tasks such as tracking and activity analysis still require discovering the network topology including the extrinsic calibration of the cameras. This work addresses the problem of calibrating a fixed camera in a wide-area camera network in a global coordinate system so that the results can be shared across calibrations. We achieve this by using commonly available mobile devices such as smartphones. At least one mobile device takes images that overlap with a fixed camera's view and records the GPS position and 3D orientation of the device when an image is captured. These sensor measurements (including the image, GPS position, and device orientation) are fused in order to calibrate the fixed camera. This article derives a novel maximum likelihood estimation formulation for finding the most probable location and orientation of a fixed camera. This formulation is solved in a distributed manner using a consensus algorithm. We evaluate the efficacy of the proposed methodology with several simulated and real-world datasets.
Radio diversity for reliable communication in sensor networks
Authors: Kusy Branislav , Abbott David , Richter Christian , Huynh Cong , Afanasyev Mikhail , Hu Wen , Brünig Michael , Ostry Diethelm , Jurdak Raja
Published: January 2014

Radio connectivity in wireless sensor networks is highly intermittent due to unpredictable and time-varying noise and interference patterns in the environment. Because link qualities are not predictable prior to deployment, current deterministic solutions to unreliable links, such as increasing network density or transmission power, require overprovisioning of network resources and do not always improve reliability.

We propose a new dual-radio network architecture to improve communication reliability in wireless sensor networks. Specifically, we show that radio transceivers operating at well-separated frequencies and spatially separated antennas offer robust communication, high link diversity, and better interference mitigation. We derive the optimal parameters for the dual-transceiver setup from frequency and space diversity in theory. We observe that frequency diversity holds the most benefits as long as the antennas are sufficiently separated to prevent coupling. Our experiments on an indoor/outdoor testbed confirm the theoretical predictions and show that radio diversity can significantly improve end-to-end delivery rates and network stability at only a small increase in energy cost over a single radio. Simulation experiments further validate the improvements in multiple topology configurations, but also reveal that the benefits of radio diversity are coupled to the number of available routing paths to the destination.
Failure detection in wireless sensor networks
Authors: Kamal Abu Raihan M. , Bleakley Chris J. , Dobson Simon
Published: January 2014

Wireless Sensor Network (WSN) technology has recently moved out of controlled laboratory settings to real-world deployments. Many of these deployments experience high rates of failure. Common types of failure include node failure, link failure, and node reboot. Due to the resource constraints of sensor nodes, existing techniques for fault detection in enterprise networks are not applicable. Previously proposed WSN fault detection algorithms either rely on periodic transmission of node status data or inferring node status based on passive information collection. The former approach significantly reduces network lifetime, while the latter achieves poor accuracy in dynamic or large networks. Herein, we propose Sequence-Based Fault Detection (SBFD), a novel framework for network fault detection in WSNs. The framework exploits in-network packet tagging using the Fletcher checksum and server-side network path analysis to efficiently deduce the path of all packets sent to the sink. The sink monitors the extracted packet paths to detect persistent path changes which are indicative of network failures. When a failure is suspected, the sink uses control messages to check the status of the affected nodes. SBFD was implemented in TinyOS on TelosB motes and its performance was assessed in a testbed network and in TOSSIM simulation. The method was found to achieve a fault detection accuracy of 90.7% to 95.0% for networks of 25 to 400 nodes at the cost of 0.164% to 0.239% additional control packets and a 0.5% reduction in node lifetime due to in-network packet tagging. Finally, a comparative study was conducted with existing solutions.
Analysis of a prioritized contention model for multimedia wireless sensor networks
Authors: Donmez Mehmet Yunus , Isik Sinan , Ersoy Cem
Published: January 2014

Emerging multimedia applications for sensor networks require the co-existence of different types of traffic with different QoS provisions in terms of latency and throughput. Prioritization-based service differentiation mechanisms are applied in all layers of communication to satisfy the QoS requirements of each traffic class. The prioritization in the contention is one of these differentiation methods applied in the medium access layer. In this article, we propose an analytical model for the contention latencies and energy expenditures of different classes in a prioritized contention structure with uniform backoff scheme. The contention window is divided into three partitions which are allocated for the use of only high-priority, both priorities, and only low-priority classes. We further generalize the model for binary exponential backoff schemes and for more than two priority classes. In the analysis, we explore the optimum sizes of these partitions in terms of contention latency and the total energy expenditure for each priority class. Our model is also useful for the evaluation of various recent contention prioritization schemes in WSNs.
Accessibility Evaluation of Classroom Captions
Authors: Kushalnagar Raja S. , Lasecki Walter S. , Bigham Jeffrey P.
Published: January 2014

Real-time captioning enables deaf and hard of hearing (DHH) people to follow classroom lectures and other aural speech by converting it into visual text with less than a five second delay. Keeping the delay short allows end-users to follow and participate in conversations. This article focuses on the fundamental problem that makes real-time captioning difficult: sequential keyboard typing is much slower than speaking. We first surveyed the audio characteristics of 240 one-hour-long captioned lectures on YouTube, such as speed and duration of speaking bursts. We then analyzed how these characteristics impact caption generation and readability, considering specifically our human-powered
collaborative captioning
approach. We note that most of these characteristics are also present in more general domains. For our caption comparison evaluation, we transcribed a classroom lecture in real-time using all three captioning approaches. We recruited 48 participants (24 DHH) to watch these classroom transcripts in an eye-tracking laboratory. We presented these captions in a randomized, balanced order. We show that both hearing and DHH participants preferred and followed collaborative captions better than those generated by automatic speech recognition (ASR) or professionals due to the more consistent
flow
of the resulting captions. These results show the potential to reliably capture speech even during sudden bursts of speed, as well as for generating “enhanced” captions, unlike other human-powered captioning approaches.
Center wheel for success
Authors: Kamp Poul-Henning
Published: January 2014

"Not invented here" syndrome is not unique to the IT world.
Provenance in sensor data management
Authors: Hensley Zachary , Sanyal Jibonananda , New Joshua
Published: January 2014

A cohesive, independent solution for bringing provenance to scientific research.
Establishing a nationwide CS curriculum in New Zealand high schools
Authors: Bell Tim
Published: January 2014

Providing students, teachers, and parents with a better understanding of computer science and programming.
Digital platforms
Authors: Ceccagnoli Marco , Forman Chris , Huang Peng , Wu D. J.
Published: January 2014

Assessing the benefits and challenges of knowledge spillovers.
Ready technology
Authors: Andriole Stephen J.
Published: January 2014

Fast-tracking emerging business technologies.
Cost-Aware Collaborative Filtering for Travel Tour Recommendations
Authors: Ge Yong , Xiong Hui , Tuzhilin Alexander , Liu Qi
Published: January 2014

Advances in tourism economics have enabled us to collect massive amounts of travel tour data. If properly analyzed, this data could be a source of rich intelligence for providing real-time decision making and for the provision of travel tour recommendations. However, tour recommendation is quite different from traditional recommendations, because the tourist’s choice is affected directly by the travel costs, which includes both financial and time costs. To that end, in this article, we provide a focused study of cost-aware tour recommendation. Along this line, we first propose two ways to represent user cost preference. One way is to represent user cost preference by a two-dimensional vector. Another way is to consider the uncertainty about the cost that a user can afford and introduce a Gaussian prior to model user cost preference. With these two ways of representing user cost preference, we develop different cost-aware latent factor models by incorporating the cost information into the probabilistic matrix factorization (PMF) model, the logistic probabilistic matrix factorization (LPMF) model, and the maximum margin matrix factorization (MMMF) model, respectively. When applied to real-world travel tour data, all the cost-aware recommendation models consistently outperform existing latent factor models with a significant margin.
Evaluation as a service for information retrieval
Authors: Lin Jimmy , Efron Miles
Published: January 2014

How can we run large-scale, community-wide evaluations of information retrieval systems if we lack the ability to distribute the document collection on which the task is based? This was the challenge we faced in the TREC Microblog tracks over the past few years. In this paper, we present a novel evaluation methodology we dub "evaluation as a service", which was implemented at TREC 2013 to address restrictions on data redistribution. The basic idea is that instead of distributing the document collection, we (the track organizers) provided a service API "in the cloud" with which participants could accomplish the evaluation task. We outline advantages as well as disadvantages of this evaluation methodology, and discuss how the approach might be extended to other evaluation scenarios.
Asian summer school in information access (ASSIA 2013)
Authors: Joho Hideo , Kando Noriko , Sakai Tetsuya , Seki Yohei , Sugimoto Shigeo
Published: January 2014

The first Asian Summer School in Information Access (ASSIA 2013) was held between 22nd and 24th June, 2013 in Tsukuba, Japan. The summer school offered 9 lectures in Information Retrieval, Web Search, and related topics, along with two panel discussions and a poster session. This reports a successful international summer school in Asia attracting a total of 63 participants from the range of countries in Asia, Europe, and North America.
ENRICH 2013
Authors: Lawless Séamus , Agosti Maristella , Conlan Owen , Clough Paul
Published: January 2014

On August 1st, 2013 the First Workshop on the Exploration, Navigation and Retrieval of Information in Cultural Heritage (ENRICH 2013) was held as part of the SIGIR 2013 conference in Dublin, Ireland. An invited talk was given by Prof. Jaap Kamps. There were 3 full papers and 3 short papers presented in addition to a poster and demonstration session. Finally, there was a lively discussion on determining the research roadmap for this specialist area of IR research. This contribution discusses the events of the workshop and outlines future directions for the community.
The second workshop of the european network for work information (ENWI)
Authors: Borlund Pia , Mandl Thomas , Womser-Hacker Christa
Published: January 2014

The second workshop of ENWI was held in Malmö, Sweden, June 12-13, 2013. ENWI is the European Network for Work Information which intends to establish a group of researchers who share a common interest in the study of workplace information practices. The better understanding of people and their tasks, and how information is part of their work is a primary goal of ENWI. Furthermore, the design and study of better technology tools supporting information practices and knowledge work is also in the focus of the network. The second workshop strengthened the network by identifying common terminology research issues and joint projects.
Report on the Scottish informatics and computing science alliance's information retrieval workshop (IRFest)
Authors: Halvey Martin , Azzopardi Leif
Published: January 2014

The 1st Scottish Information Retrieval Workshop took place in May, 2013 in Glasgow. The focus of the workshop was on bringing together IR researchers from the various Scottish universities in order to facilitate more awareness and increased interaction. The scientific program included a minute madness session, research talks, demos and posters. The keynote was delivered by Prof. Arjen de Vries who provided an overview of the problems, opportunities and challenges of finding strategic information within the enterprise.
Living analytics methods for the social web
Authors: Diaz-Aviles Ernesto
Published: January 2014

The collective effervescence of social media production has been enjoying a great deal of success in recent years. The hundred of millions of users who are actively participating in the Social Web are exposed to ever-growing amounts of sites, relationships, and information.

This work contributes state-of-the-art methods and techniques to the emerging field of
Living Analytics
, whose main goal is to capture people interactions in real-time and to analyze these data in order to relieve information overload. We introduce intelligent filtering approaches that exploit social interactions, multidimensional relationships, metadata, and other data becoming ubiquitous in the social web, in order to discover and recommend the most relevant and attractive information that meets users' individual needs. In particular, the contributions of this work fall into mainly two categories.

(i)
Recommender Systems
: We present novel algorithms that advance the state-of-the-art in Online Collaborative Filtering. Moreover, we propose an approach based on Swarm Intelligence to directly optimize ranking functions for item recommendations. New approaches to address the cold-start problem in social recommender systems are also part of our contributions. In addition, we also offer a personalized ranking algorithm for Epidemic Intelligence.

(ii)
Collective Intelligence
: Our contributions in the field of computational social science are twofold. First, we explore how social media streams can be exploited for Epidemic Intelligence and show its potential for early warning detection and outbreak analysis and control. Second, we show how the real-time nature of social media streams can be leveraged to take the pulse of political emotions.

In total, the methods and studies included in this work constitute an analytics toolbox to help understand and analyze the social web.