bluuebunny/crossref_metadata_2025 huggingface dataset:
Quiescent period respiratory gating for PET/CT
Authors: Liu Chi , Alessio Adam , Pierce Larry , Thielemans Kris , Wollenweber Scott , Ganin Alexander , Kinahan Paul
Published: August 2010

Purpose:

To minimize respiratory motion artifacts, this work proposes quiescent period gating (QPG) methods that extract PET data from the end‐expiration quiescent period and form a single PET frame with reduced motion and improved signal‐to‐noise properties.

Methods:

Two QPG methods are proposed and evaluated. Histogram‐based quiescent period gating (H‐QPG) extracts a fraction of PET data determined by a window of the respiratory displacement signal histogram. Cycle‐based quiescent period gating (C‐QPG) extracts data with a respiratory displacement signal below a specified threshold of the maximum amplitude of each individual respiratory cycle. Performances of both QPG methods were compared to ungated and five‐bin phase‐gated images across 21 FDG‐PET/CT patient data sets containing 31 thorax and abdomen lesions as well as with computer simulations driven by 1295 different patient respiratory traces. Image quality was evaluated in terms of the lesion and the fraction of counts included in each gate as a surrogate for image noise.

Results:

For all the gating methods, image noise artifactually increases when the fraction of counts included in each gate is less than 50%. While simulation data show that H‐QPG is superior to C‐QPG, the H‐QPG and C‐QPG methods lead to similar quantification‐noise tradeoffs in patient data. Compared to ungated images, both QPG methods yield significantly higher lesion . Compared to five‐bin phase gating, the QPG methods yield significantly larger fraction of counts with similar improvement. Both QPG methods result in increased lesion for patients whose lesions have longer quiescent periods.

Conclusions:

Compared to ungated and phase‐gated images, the QPG methods lead to images with less motion blurring and an improved compromise between and fraction of counts. The QPG methods for respiratory motion compensation could effectively improve tumor quantification with minimal noise increase.
Dosimetric characterization of a multileaf collimator for a new four‐dimensional image‐guided radiotherapy system with a gimbaled x‐ray head, MHI‐TM2000a)
Authors: Nakamura Mitsuhiro , Sawada Akira , Ishihara Yoshitomo , Takayama Kenji , Mizowaki Takashi , Kaneko Shuji , Yamashita Mikiko , Tanabe Hiroaki , Kokubo Masaki , Hiraoka Masahiro
Published: August 2010

Purpose:

To present the dosimetric characterization of a multileaf collimator (MLC) for a new four‐dimensional image‐guided radiotherapy system with a gimbaled x‐ray head, MHI‐TM2000.

Methods:

MHI‐TM2000 has an x‐ray head composed of an ultrasmall linear accelerator guide and a system‐specific MLC. The x‐ray head can rotate along the two orthogonal gimbals (pan and tilt rotations) up to ±2.5°, which swings the beam up to ±41.9 mm in each direction from the isocenter on the isocenter plane perpendicular to the beam. The MLC design is a single‐focus type, has 30 pairs of 5 mm thick leaves at the isocenter, and produces a maximum field size of. Leaf height and length are 110 and 260 mm, respectively. Each leaf end is circular, with a radius of curvature of 370 mm. The distance that each leaf passes over the isocenter is 77.5 mm. Radiation leakage between adjacent leaves is minimized by an interlocking tongue‐and‐groove (T&G) arrangement with the height of the groove part 55 mm. The dosimetric characterizations including field characteristics, leaf position accuracy, leakage, and T&G effect were evaluated using a well‐commissioned 6 MV photon beam, EDR2 films (Kodak, Rochester, NY), and water‐equivalent phantoms. Furthermore, the field characteristics and leaf position accuracy were evaluated under conditions of pan or tilt rotation.

Results:

The differences between nominal and measured field sizes were within ±0.5 mm. Although the penumbra widths were greater with wider field size, the maximum width was even for the fully opened field. Compared to the results of field characteristics without pan or tilt rotation, the variation in field size, penumbra width, flatness, and symmetry was within ±1 mm/1% at the maximum pan or tilt rotational angle. The leaf position accuracy was , ranging from −0.3 to 0.2 mm at four gantry angles of 0°, 90°, 180°, and 270° with and without pan or tilt rotation. The interleaf leakage was up to 0.21%, whereas the intraleaf leakage was . T&G decreased the doses by 10.7%, on average.

Conclusions:

This study demonstrated that MHI‐TM2000 has the capability for high leaf position accuracy and low leakage, leading to highly accurate intensity‐modulated radiotherapy delivery. Furthermore, substantial changes in the dosimetric data on field characteristics and leaf position accuracy were not observed even at the maximum pan or tilt rotation.
A dose distribution evaluation technique using the k‐d tree for nearest neighbor searching
Authors: Yuan Jiankui , Chen Weimin
Published: August 2010

Purpose:

The authors propose an algorithm based on the k‐d tree for nearest neighbor searching to improve the calculation time for 2D and 3D dose distributions.

Methods:

The calculation method has been widely used for comparisons of dose distributions in clinical treatment plans and quality assurances. By specifying the acceptable dose and distance‐to‐agreement criteria, the method provides quantitative measurement of the agreement between the reference and evaluation dose distributions. The value indicates the acceptability. In regions where , the predefined criterion is satisfied and thus the agreement is acceptable; otherwise, the agreement fails. Although the concept of the method is not complicated and a quick naïve implementation is straightforward, an efficient and robust implementation is not trivial. Recent algorithms based on exhaustive searching within a maximum radius, the geometric Euclidean distance, and the table lookup method have been proposed to improve the computational time for multidimensional dose distributions. Motivated by the fact that the least searching time for finding a nearest neighbor can be an operation with a k‐d tree, where is the total number of the dose points, the authors propose an algorithm based on the k‐d tree for the evaluation in this work.

Results:

In the experiment, the authors found that the average k‐d tree construction time per reference point is, while the nearest neighbor searching time per evaluation point is proportional to , where is between 2 and 3 for two‐dimensional and three‐dimensional dose distributions, respectively.

Conclusions:

Comparing with other algorithms such as exhaustive search and sorted list, the k‐d tree algorithm for evaluation is much more efficient.
An investigation of 4D cone‐beam CT algorithms for slowly rotating scanners
Authors: Bergner Frank , Berkus Timo , Oelhafen Markus , Kunz Patrik , Pan Tinsu , Grimmer Rainer , Ritschl Ludwig , Kachelrieß Marc
Published: August 2010

Purpose:

To evaluate several algorithms for 4D cone‐beam computed tomography (4D CBCT) with slow rotating devices. 4D CBCT is used to perform phase‐correlated (PC) reconstructions of moving objects, such as breathing patients, for example. Such motion phase‐dependent reconstructions are especially useful for updating treatment plans in radiation therapy. The treatment plan can be registered more precisely to the motion of the tumor and, in consequence, the irradiation margins for the treatment, the so‐called planning target volume, can be reduced significantly.

Methods:

In the study, several algorithms were evaluated for kilovoltage cone‐beam CT units attached to linear particle accelerators. The reconstruction algorithms were the conventional PC reconstruction, the McKinnon–Bates (MKB) algorithm, the prior image constrained compressed sensing (PICCS) approach, a total variation minimization (ASD‐POCS) algorithm, and the autoadaptive phase correlation (AAPC) algorithm. For each algorithm, the same motion‐affected raw data were used, i.e., one simulated and one measured data set. The reconstruction results from the authors’ implementation of these algorithms were evaluated regarding their noise and artifact levels, their residual motion blur, and their computational complexity and convergence.

Results:

In general, it turned out that the residual motion blur was lowest in those algorithms which exclusively use data from a single motion phase. Algorithms using the image from the full data set as initialization or as a reference for the reconstruction were not capable of fully removing the motion blurring. The iterative algorithms, especially approaches based on total variation minimization, showed lower noise and artifact levels but were computationally complex. The conventional methods based on a single filtered backprojection were computationally inexpensive but suffered from higher noise and streak artifacts which limit the usability. In contrast, these methods showed to be less demanding and more predictable in their outcome than the total variation minimization based approaches.

Conclusions:

The reconstruction algorithms including at least one iterative step can reduce the 4D CBCT specific artifacts. Nevertheless, the algorithms that use the full data set, at least for initialization, such as MKB and PICCS in the authors’ implementation, are only a trade‐off and may not fully achieve the optimal temporal resolution. A predictable image quality as seen in conventional reconstruction methods, i.e., without total variation minimization, is a desirable property for reconstruction algorithms. Fast, iterative approaches such as the MKB can therefore be seen as a suitable tradeoff.
Feasibility of high temporal resolution breast DCE‐MRI using compressed sensing theory
Authors: Wang Haoyu , Miao Yanwei , Zhou Kun , Yu Yanming , Bao Shanglian , He Qiang , Dai Yongming , Xuan Stephanie Y. , Tarabishy Bisher , Ye Yongquan , Hu Jiani
Published: August 2010

Purpose:

To investigate the feasibility of high temporal resolution breast DCE‐MRI using compressed sensing theory.

Methods:

Two experiments were designed to investigate the feasibility of using reference image based compressed sensing (RICS) technique in DCE‐MRI of the breast. The first experiment examined the capability of RICS to faithfully reconstruct uptake curves using undersampled data sets extracted from fully sampled clinical breast DCE‐MRI data. An average approach and an approach using motion estimation and motion compensation (ME/MC) were implemented to obtain reference images and to evaluate their efficacy in reducing motion related effects. The second experiment, anin vitro phantom study, tested the feasibility of RICS for improving temporal resolution without degrading the spatial resolution.

Results:

For the uptake‐curve reconstruction experiment, there was a high correlation between uptake curves reconstructed from fully sampled data by Fourier transform and from undersampled data by RICS, indicating high similarity between them. The mean Pearson correlation coefficients for RICS with the ME/MC approach and RICS with the average approach were and , respectively. The comparisons of final reconstruction results between RICS with the average approach and RICS with the ME/MC approach suggested that the latter was superior to the former in reducing motion related effects. For the in vitro experiment, compared to the fully sampled method, RICS improved the temporal resolution by an acceleration factor of 10 without degrading the spatial resolution.

Conclusions:

The preliminary study demonstrates the feasibility of RICS for faithfully reconstructing uptake curves and improving temporal resolution of breast DCE‐MRI without degrading the spatial resolution.
A solid‐state amorphous selenium avalanche technology for low photon flux imaging applications
Authors: Wronski M. M. , Zhao W. , Reznik A. , Tanioka K. , DeCrescenzo G. , Rowlands J. A.
Published: August 2010

Purpose:

The feasibility of a practical solid‐state technology for low photon flux imaging applications was investigated. The technology is based on an amorphous selenium photoreceptor with a voltage‐controlled avalanche multiplication gain. If this photoreceptor can provide sufficient internal gain, it will be useful for an extensive range of diagnostic imaging systems.

Methods:

The avalanche photoreceptor under investigation is referred to as HARP‐DRL. This is a novel concept in which a high‐gain avalanche rushing photoconductor (HARP) is integrated with a distributed resistance layer (DRL) and sandwiched between two electrodes. The avalanche gain and leakage current characteristics of this photoreceptor were measured.

Results:

HARP‐DRL has been found to sustain very high electric field strengths without electrical breakdown. It has shown avalanche multiplication gains as high as and a very low leakage current .

Conclusions:

This is the first experimental demonstration of a solid‐state amorphous photoreceptor which provides sufficient internal avalanche gain for photon counting and photon starved imaging applications.
Environment Matters
Authors: Hines Pamela J.
Published: August 2010

Muscle stem cells prefer a soft substrate.
In VitroMitochondrial Toxicity of Metacavir, a New Nucleoside Reverse Transcriptase Inhibitor for Treatment of Hepatitis B Virus
Authors: Zhang Pinghu , Zhang Luyong , Jiang Zhenzhou , Wang Tao , Chen Hongkui , Xiong Yating , Li Zhan
Published: August 2010

Therapy with nucleoside reverse transcriptase inhibitors (NRTIs) can be associated with mitochondrial toxicity.In vitrostudies have been used to predict the predisposition for and characterize the mechanisms causing mitochondrial toxicity. Metacavir (PNA) is a novel synthetic nucleoside analog for oral administration with potent and specific antiviral activity against hepatitis B virus (HBV). We assessed the potential for mitochondrial toxicity of PNA in long-term cultures of HepG2 hepatoma cells by measuring mitochondrial function (through lactate secretion), levels of mitochondrial DNA (mtDNA), and the activities of respiratory-chain complexes I to IV. Exposure of HepG2 cells to PNA at concentrations up to 50 μM for 15 days resulted in no deleterious effect on cell proliferation, levels of lactate or mtDNA, or enzyme activities of respiratory-chain complexes I to IV. In contrast, dideoxycytosine at 10 μM and zidovudine at 50 μM have significant effects on cell proliferation, levels of lactate and mtDNA, and enzyme activities of respiratory-chain complexes I to IV. However, PNA at a supratherapeutic concentration of 250 μM could result in significant alterations in the levels of mtDNA and the activities of respiratory-chain complex enzymes, revealing evidence of the potential mitochondrial toxicity of PNA. In summary, thesein vitroresults indicate that the potential for PNA to interfere with mitochondrial functions is low.
Should Moxifloxacin Be Used for the Treatment of Extensively Drug-Resistant Tuberculosis? An Answer from a Murine Model
Authors: Poissy Julien , Aubry Alexandra , Fernandez Christine , Lott Marie-Catherine , Chauffour Aurelie , Jarlier Vincent , Farinotti Robert , Veziris Nicolas
Published: August 2010

The prevalence of extensively drug-resistant tuberculosis (XDR-TB), defined as TB that is resistant to isoniazid, rifampin, fluoroquinolones, and aminoglycosides, is rising worldwide. The extent of
Mycobacterium tuberculosis
resistance to fluoroquinolones depends on the mutation in the DNA gyrase, the only target of fluoroquinolones. The MIC of moxifloxacin, the most active fluoroquinolone against
M. tuberculosis
, may be lower than its peak serum level for some ofloxacin-resistant strains of
Mycobacterium tuberculosis
. Therefore, if the MIC of moxifloxacin is lower than its peak serum level, it may be effective against XDR-TB. Our objective was to determine the efficacy of moxifloxacin in treating ofloxacin-resistant TB. We selected isogenic fluoroquinolone-resistant mutants of
M. tuberculosis
H37Rv
in vivo
. We infected Swiss mice with either wild-type H37Rv or one of three mutant strains with different MICs that are commonly seen in clinical practice. The MICs of the mutant strains ranged from below to above the peak moxifloxacin level seen in humans (3 μg/ml). Each mouse was treated with one of four moxifloxacin doses for 1 month. Moxifloxacin was effective against mutant strain GyrB D500N, with the lowest MIC (0.5 μg/ml), when the standard dose was doubled. Moxifloxacin reduced mortality in mice infected with mutant strain GyrA A90V with an intermediate MIC (2 μg/ml). However, it had no impact on the mutant strain GyrA D94G with the highest MIC (4 μg/ml). Our study underscores current WHO recommendations to use moxifloxacin when there is resistance to early-generation fluoroquinolones such as ofloxacin, restricting this recommendation to strains with moxifloxacin MICs of less than or equal to 2 μg/ml.
Reduced Expression of the
vca0421
Gene of
Vibrio cholerae
O1 Results in Innate Resistance to Ciprofloxacin
Authors: Okuda Jun , Hayashi Naoki , Wakahara Yuka , Gotoh Naomasa
Published: August 2010

A mini-Tn
5
insertion into a ciprofloxacin (CIP)-resistant mutant of
Vibrio cholerae
O1 revealed that overexpression of the
vca0421
gene, which encodes a hypothetical protein, in the CIP-resistant mutant carrying a mutation in the quinolone resistance-determining region (QRDR) of the
gyrA
gene causes sensitization to CIP. We propose a new intrinsic mechanism of resistance to fluoroquinolones due to the inherently reduced expression of the
vca0421
gene in
V. cholerae
O1.
Translocation of
Pseudomonas aeruginosa
from the Intestinal Tract Is Mediated by the Binding of ExoS to an Na,K-ATPase Regulator, FXYD3
Authors: Okuda Jun , Hayashi Naoki , Okamoto Masashi , Sawada Shinji , Minagawa Shu , Yano Yoshitaka , Gotoh Naomasa
Published: August 2010

The intestinal tract is considered the most important reservoir of
Pseudomonas aeruginosa
in intensive care units (ICUs). Gut colonization by
P. aeruginosa
underlies the development of invasive infections such as gut-derived sepsis. Intestinal colonization by
P. aeruginosa
is associated with higher ICU mortality rates. The translocation of endogenous
P. aeruginosa
from the colonized intestinal tract is an important pathogenic phenomenon. Here we identify bacterial and host proteins associated with bacterial penetration through the intestinal epithelial barrier. We first show by comparative genomic hybridization analysis that the
exoS
gene, encoding the type III effector protein, ExoS, was specifically detected in a clinical isolate that showed higher virulence in silkworms following midgut injection. We further show using a silkworm oral infection model that
exoS
is required both for virulence and for bacterial translocation from the midgut to the hemolymph. Using a bacterial two-hybrid screen, we show that the mammalian factor FXYD3, which colocalizes with and regulates the function of Na,K-ATPase, directly binds ExoS. A pulldown assay revealed that ExoS binds to the transmembrane domain of FXYD3, which also interacts with Na,K-ATPase. Na,K-ATPase controls the structure and barrier function of tight junctions in epithelial cells. Collectively, our results suggest that ExoS facilitates
P. aeruginosa
penetration through the intestinal epithelial barrier by binding to FXYD3 and thereby impairing the defense function of tight junctions against bacterial penetration.
Role of
Porphyromonas gingivalis
Phosphoserine Phosphatase Enzyme SerB in Inflammation, Immune Response, and Induction of Alveolar Bone Resorption in Rats
Authors: Bainbridge Brian , Verma Raj K. , Eastman Christie , Yehia Bilal , Rivera Mercedes , Moffatt Catherine , Bhattacharyya Indraneel , Lamont Richard J. , Kesavalu Lakshmyya
Published: August 2010

Porphyromonas gingivalis
secretes a serine phosphatase enzyme, SerB, upon contact with gingival epithelial cells
in vitro
. The SerB protein plays a critical role in internalization and survival of the organism in epithelial cells. SerB is also responsible for the inhibition of interleukin-8 (IL-8) secretion from gingival epithelial cells infected with
P. gingivalis
. This study examined the ability of a
P. gingivalis
SerB mutant to colonize the oral cavity and induce gingival inflammation, immune responses, and alveolar bone resorption in a rat model of periodontal disease. Both
P. gingivalis
ATCC 33277 and an isogenic ΔSerB mutant colonized the oral cavities of rats during the 12-week experimental period. Both of the strains induced significant (
P
< 0.05) systemic levels of immunoglobulin G (IgG) and isotypes IgG1, IgG2a, and IgG2b, indicating the involvement of both T helper type 1 (Th1) and Th2 responses to infection. Both strains induced significantly (
P
< 0.05) higher levels of alveolar bone resorption in infected rats than in sham-infected control rats. However, horizontal and interproximal alveolar bone resorption induced by the SerB mutant was significantly (
P
< 0.05) lower than that induced by the parental strain. Rats infected with the ΔSerB mutant exhibited significantly higher levels of apical migration of the junctional epithelium (
P
< 0.01) and polymorphonuclear neutrophil (PMN) recruitment (
P
< 0.001) into the gingival tissues than rats infected with the wild type. In conclusion, in a rat model of periodontal disease, the SerB phosphatase of
P. gingivalis
is required for maximal alveolar bone resorption, and in the absence of SerB, more PMNs are recruited into the gingival tissues.
Adhesion, Invasion, and Agglutination Mediated by Two Trimeric Autotransporters in the Human Uropathogen
Proteus mirabilis
Authors: Alamuri Praveen , Löwer Martin , Hiss Jan A. , Himpsl Stephanie D. , Schneider Gisbert , Mobley Harry L. T.
Published: August 2010

Fimbriae of the human uropathogen
Proteus mirabilis
are the only characterized surface proteins that contribute to its virulence by mediating adhesion and invasion of the uroepithelia. PMI2122 (AipA) and PMI2575 (TaaP) are annotated in the genome of strain HI4320 as trimeric autotransporters with “adhesin-like” and “agglutinating adhesin-like” properties, respectively. The C-terminal 62 amino acids (aa) in AipA and 76 aa in TaaP are homologous to the translocator domains of YadA from
Yersinia enterocolitica
and Hia from
Haemophilus influenzae
. Comparative protein modeling using the Hia three-dimensional structure as a template predicted that each of these domains would contain four antiparallel beta sheets and that they formed homotrimers. Recombinant AipA and TaaP were seen as ∼28 kDa and ∼78 kDa, respectively, in
Escherichia coli
, and each also formed high-molecular-weight homotrimers, thus supporting this model.
E. coli
synthesizing AipA or TaaP bound to extracellular matrix proteins with a 10- to 60-fold-higher level of affinity than the control strain. Inactivation of
aipA
in
P. mirabilis
strains significantly (
P
< 0.01) reduced the mutants' ability to adhere to or invade HEK293 cell monolayers, and the functions were restored upon complementation. A 51-aa-long invasin region in the AipA passenger domain was required for this function.
E. coli
expressing TaaP mediated autoagglutination, and a
taaP
mutant of
P. mirabilis
showed significantly (
P
< 0.05) more reduced aggregation than HI4320. Gly-247 in AipA and Gly-708 in TaaP were indispensable for trimerization and activity. AipA and TaaP individually offered advantages to
P. mirabilis
in a murine model. This is the first report characterizing trimeric autotransporters in
P. mirabilis
as afimbrial surface adhesins and autoagglutinins.
Socioeconomic impact of road traffic injuries in West Africa: exploratory data from Nigeria
Authors: Juillard Catherine , Labinjo Mariam , Kobusingye Olive , Hyder Adnan A
Published: August 2010

Background

Road traffic injuries (RTIs) are increasingly contributing to the burden of disease in sub-Saharan Africa, yet little is known about the economic consequences and disability associated with them.

Objective

To explore cost and disability consequences of RTIs in Nigeria.

Design

A population-based survey using two-stage stratified cluster sampling.

Subject/setting

Information on care-seeking choice, cost of treatment, ability to work, reduction in earnings, and disability were collected on 127 subjects who had suffered an RTI, of 3082 study subjects in seven Nigerian states.

Outcome measures

Univariate analysis was used to estimate frequency of disability, types of care sought, and trends for work lost, functional ability and cost of treatment. Unadjusted bivariate analysis was performed to explore care-seeking, cost of care, and work lost among disabled and non-disabled people.

Results

RTIs resulted in disability for 29.1% of subjects, while 13.5% were unable to return to work. Of the disabled people, 67.6% were unable to perform activities of daily living, 16.7% consequently lost their jobs, and 88.6% had a reduction in earnings. Private physician and hospital treatment were the most common forms of initial treatment sought, but traditional treatment was the most common second form of care sought. Average direct costs of informal and formal treatment were US$6.65 and US$35.64, respectively. Disabled people were more likely to seek formal care (p=0.003) and be unable to work (p=0.002).

Conclusions

Economic and functional ramifications must be included in the spectrum of consequences of RTIs to fully appreciate the extent of the burden of disease, implying that health systems should not only address the clinical consequences of RTIs, but the financial ones as well.
Decline in hospitalisations due to dog bite injuries in Catalonia, 1997–2008. An effect of government regulation?
Authors: Villalbí Joan R , Cleries Montse , Bouis Susana , Peracho Víctor , Duran Julia , Casas Conrad
Published: August 2010

Objective

To analyse population-based data on hospitalisation caused by dog bite injuries after changes in legal regulations on dog ownership, including breed-specific regulations.

Design

Descriptive study.

Setting

Hospitals in Catalonia (Spain), 1997–2008.

Subjects

Persons hospitalised with injuries caused by dog bites.

Results

There has been a significant decline in hospitalisation caused by injuries from dog bites from 1.80/100 000 in 1997–9 to 1.11/100 000 in 2006–8, after the enactment of stricter regulations on dog ownership in 1999 and 2002. The magnitude of this change is significant (−38%), and has been greatest in less urban settings.

Conclusions

Government regulations were associated with a sizable decrease in injuries caused by dog bites in Catalonia. More evaluative studies in this field may provide criteria to focus future regulations and other preventive interventions.
Horse-related facial injuries: the perceptions and experiences of riding schools
Authors: Meredith Lydia , Antoun Joseph S
Published: August 2010

This study aimed to investigate the perceptions and experiences of New Zealand horse riding schools with regard to horse-related facial injuries. All the riding schools listed in the New Zealand electronic phonebook directory were surveyed by post. The survey questions covered riding schools' perceptions of rider profile, general and facial injury patterns and safety equipment used. The face was perceived to be the most common injury site by only 4% of respondents. Helmets were enforced in only 35% of the schools during unmounted activities. Nearly half the schools did not enforce any safety equipment for unmounted equestrians. Falls were perceived to be the most common cause of facial injury (41%), ahead of horse kicks (9%). Poor handling was cited as the most likely cause for horse kick-related injuries (67%). In summary, riding schools did not perceive the face to be among the most common horse-related injury sites. Safety protocols were generally directed towards mounted equestrians.
PROPERTIES OF THE SUPERCONDUCTING GAP RATIO IN THE VAN HOVE SCENARIO OF HIGH-Tc OXIDES
Authors: BECHLAGHEM A. , BOURBIE D.
Published: August 2010

The superconducting gap ratio R = 2Δ(0)/kBTc has been studied in the context when the Fermi level is close to the van Hove singularity. In this approach, we consider the interaction is related to the phonons at low temperature but at high temperature, it is relevant to the magnetic excitations. Our results show that the superconducting gap ratio R takes large values in qualitative agreement with experimental data.
Kyoto prize and other CS awards
Authors: Rosenberger Jack
Published: August 2010

László Lovász, Vinton G. Cerf, and other researchers are honored for their contributions to computer science.
Return at risk
Authors: Armour Phillip G.
Published: August 2010

Calculating the likely true cost of projects.
Principles of the law of software contracts
Authors: Hillman Robert A. , O'Rourke Maureen A.
Published: August 2010

An overview of a new set of legal principles for software contracts developed by the American Law Institute.
Discussing cyber attack
Authors: Denning Peter J. , Denning Dorothy E.
Published: August 2010

Cyber attack---the other side of cyber defense---deserves a more open discussion than it has been getting.
Future Internet architecture
Authors: Rexford Jennifer , Dovrolis Constantine
Published: August 2010

Should researchers focus on designing new network architectures or improving the current Internet?
Erlang
Authors: Armstrong Joe
Published: August 2010

The same component isolation that made it effective for large distributed telecom systems makes it effective for multicore CPUs and networked applications.
Confronting the myth of rapid obsolescence in computing research
Authors: Sjøberg Dag I. K.
Published: August 2010

Computing research ages more slowly than research in other scientific disciplines, supporting the call for parity in funding.
Privacy integrated queries
Authors: McSherry Frank
Published: August 2010

Privacy Integrated Queries (PINQ) is an extensible data analysis platform designed to provide unconditional privacy guarantees for the records of the underlying data sets. PINQ provides analysts with access to records through an SQL-like declarative language (LINQ) amidst otherwise arbitrary C# code. At the same time, the design of PINQ's analysis language and its careful implementation provide formal guarantees of
differential privacy
for any and all uses of the platform. PINQ's guarantees require no trust placed in the expertise or diligence of the analysts, broadening the scope for design and deployment of privacy-preserving data analyses, especially by privacy nonexperts.
MEDiSN
Authors: Ko Jeonggil , Lim Jong Hyun , Chen Yin , Musvaloiu-E Rvăzvan , Terzis Andreas , Masson Gerald M. , Gao Tia , Destler Walt , Selavo Leo , Dutton Richard P.
Published: August 2010

Staff shortages and an increasingly aging population are straining the ability of emergency departments to provide high quality care. At the same time, there is a growing concern about hospitals' ability to provide effective care during disaster events. For these reasons, tools that automate patient monitoring have the potential to greatly improve efficiency and quality of health care. Towards this goal, we have developed
MEDiSN
, a wireless sensor network for monitoring patients' physiological data in hospitals and during disaster events. MEDiSN comprises
Physiological Monitors
(PMs), which are custom-built, patient-worn motes that sample, encrypt, and sign physiological data and
Relay Points
(RPs) that self-organize into a multi-hop wireless backbone for carrying physiological data. Moreover, MEDiSN includes a back-end server that persistently stores medical data and presents them to authenticated GUI clients. The combination of MEDiSN's two-tier architecture and optimized rate control protocols allows it to address the compound challenge of reliably delivering large volumes of data while meeting the application's QoS requirements. Results from extensive simulations, testbed experiments, and multiple pilot hospital deployments show that MEDiSN can scale from tens to at least five hundred PMs, effectively protect application packets from congestive and corruptive losses, and deliver medically actionable data.
Looking at near-duplicate videos from a human-centric perspective
Authors: Oliveira Rodrigo De , Cherubini Mauro , Oliver Nuria
Published: August 2010

Popular content in video sharing websites (e.g., YouTube) is usually replicated via identical copies or near-duplicates. These duplicates are usually studied because they pose a threat to site owners in terms of wasted disk space, or privacy infringements. Furthermore, this content might potentially hinder the users' experience in these websites. The research presented in this article focuses around the central argument that there is no agreement on the technical definition of what these near-duplicates are, and, more importantly, there is no strong evidence that users of video sharing websites would like this content to be removed. Most scholars define near-duplicate video clips (NDVC) by means of non-semantic features (e.g., different image/audio quality), while a few also include semantic features (i.e., different videos of similar content). However, it is unclear what features contribute to the human perception of near-duplicate videos. The findings of four large scale online surveys that were carried out in the context of our research confirm the relevance of both types of features. Some of our findings confirm the adopted definitions of NDVC whereas other findings are surprising: Near-duplicate videos with different image quality, audio quality, or with/without overlays were perceived as NDVC. However, the same could not be verified when videos differed by more than one of these features at the same time. With respect to semantics, it is yet unclear the exact role that it plays in relation to the features that make videos alike. From a user's perspective, participants preferred in most cases to see only one of the NDVC in the search results of a video search query and they were more tolerant to changes in the audio than in the video tracks. Based on all these findings, we propose a new user-centric NDVC definition and present implications for how duplicate content should be dealt with by video sharing Web sites.
Project SAGE, a half-century on
Authors: King John Leslie
Published: August 2010

John Leslie King's interest in history was evident at the first CSCW conference in 1986. His review of 15 years of research with technology to support real-time collocated interaction, then called Group Decision Support Systems, revealed that we sometimes learn more slowly from experience than we could. In this article, he describes the little-known system that pioneered real-time human-computer interaction in the 1950s, created the computing profession, and trained hundreds of its earliest practitioners.---Jonathan Grudin
Network-aware, energy-conscious, fair service for real-time applications on multiprocessor SoC
Authors: Chantem Thidapat , Hu X. Sharon , Poellabauer Christian , Yi Jun , Zhang Liqiang
Published: August 2010

We consider systems consisting of wireless nodes that execute CPU intensive applications on multiprocessor systemon- a-chip (MPSoC) and must transmit packets over the network in a timely manner. Existing methods do not consider packet deadlines in conjunction with energy and real-time task performance, making it hard to predict system behavior. We present an energy-aware adaptive CPU scheduling algorithm to maximize the number of packet deadlines met in a fair manner and discuss future work.
Finding an upper bound on the increase in execution time due to contention on the memory bus in COTS-based multicore systems
Authors: Andersson Björn , Easwaran Arvind , Lee Jinkyu
Published: August 2010

Contention on the memory bus in COTS based multicore systems is becoming a major determining factor of the execution time of a task. Analyzing this extra execution time is non-trivial because (i) bus arbitration protocols in such systems are often undocumented and (ii) the times when the memory bus is requested to be used are not explicitly controlled by the operating system scheduler; they are instead a result of cache misses. We present a method for finding an upper bound on the extra execution time of a task due to contention on the memory bus in COTS based multicore systems. This method makes no assumptions on the bus arbitration protocol (other than assuming that it is work-conserving).
Multiprocessor real-time scheduling considering concurrency and urgency
Authors: Lee Jinkyu , Easwaran Arvind , Shin Insik , Lee Insup
Published: August 2010

It has been widely studied how to schedule realtime tasks on multiprocessor platforms. Several studies find optimal scheduling policies for implicit deadline task systems, but it is hard to understand how each policy utilizes the two important aspects of scheduling real-time tasks on multiprocessors: inter-job concurrency and job urgency. In this paper, we introduce a new scheduling policy that considers these two properties. We prove that the policy is optimal for the special case when the execution time of all tasks are equally one and deadlines are implicit, and observe that the policy is a new concept in that it is not an instance of Pfair or ERfair. It remains open to find a scheduliability condition for general task systems under our scheduling policy.
Globally distributed teams
Authors: Garrison Gary , Wakefield Robin L. , Xu Xiaobo , `Kim Sang Hyun
Published: August 2010

Globally distributed teams are becoming more common among organizations that seek to maximize knowledge creation and innovation for competitive advantage. Although they are becoming widely used among global organizations, distributed teams are creating an environment replete in cultural and functional diversity. Whereas synergy among members is desired, diversity is likely to hinder team cohesion and individual performance. Our study models and empirically tests the effect of perceptions of diversity on trust, cohesion, and individual performance in actual globally distributed teams. The results indicate that individual productivity is negatively influenced by the extent of diversity within a team; however, this liability may be restrained if an environment of trust is encouraged and team cohesion develops.
Who is out there?
Authors: Heart Tsipi
Published: August 2010

Software as a Service (SaaS) is a relatively new organizational application sourcing alternative, offering organizations the option to access applications--via the Internet--that are remotely hosted on offsite servers instead of installing equivalent applications in-house, thus presumably saving costs. Although SaaS has been offered since the late 1990s, so far it has not become a dominant sourcing alternative for organizational core applications, in spite of the fact that most leading IT companies now offer remotely-hosted organization-wide applications. This study conceptualized and empirically tested a model of the effects of the perceived risk of SaaS and trust in the SaaS vendor community on the organizational intention to adopt SaaS at this early stage of the SaaS market. Three novel, risk-related constructs were developed: perceived risk of SaaS, perceived risk of systems unavailability, and perceived risk of data insecurity. Likewise, three new trust-related constructs were also conceived: trust in the SaaS vendor community, perceived capabilities and perceived reputation of the SaaS vendor community. An empirical test of the model demonstrated the negative effect of perceived risk and the positive effects of trust in, and the reputation of, the SaaS vendor community, on the intention to adopt SaaS. Trust in the SaaS vendor community was also found to strongly affect all three risk concepts.
Preliminary design of future reconfigurable IMA platforms
Authors: Bieber Pierre , Noulard Eric , Pagetti Claire , Planche Thierry , Vialard Francois
Published: August 2010

The next generation of IMA platforms should include reconfiguration capabilities in order to limit the effect of hardware failures on aircraft operational reliability. In this paper, we investigate architecture principles for such platforms and propose adequate reconfiguration services. A preliminary analysis of the design feasibility and its contribution to operational reliability is performed. The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7 / 2007-2013) under Grant Agreement no ACP7-GA-2008-211439.
Model driven code generation for critical and adaptative embedded systems
Authors: Borde Etienne , Feiler Peter H. , Haïk Grégory , Pautet Laurent
Published: August 2010

Implementing adaptative systems requires to make the trade off of (i) the adaptation promptness, (ii) the amount of interferences due to adaptation, and (iii) the guarantee of data ows consistency. Furthermore, implementing critical systems requires to respect design constraints that enable to improve its determinism.

In this paper, we propose a design methodology that helps to make the adaptation trade off while respecting the critical systems design specificities. We then illustrate the usage of this methodology on an industrial use-case, using a component-based framework that generates the adaptation code. Lastly, we present and discuss the associated experimental results, and show the relative benefits of using the one or the other mode switch protocol.
The Lyapunov Stability for the Linear and Nonlinear Damped Oscillator with Time‐Periodic Parameters
Authors: Chu Jifeng , Xia Ting
Published: August 2010

Let a(t), b(t) be continuous T‐periodic functions with . We establish one stability criterion for the linear damped oscillator x′′ + b(t)x′ + a(t)x = 0. Moreover, based on the computation of the corresponding Birkhoff normal forms, we present a sufficient condition for the stability of the equilibrium of the nonlinear damped oscillator x′′ + b(t)x′ + a(t)x + c(t)x2n−1 + e(t, x) = 0, where n ≥ 2, c(t) is a continuous T‐periodic function, e(t, x) is continuous T‐periodic in t and dominated by the power x2n in a neighborhood of x = 0.
No Difference in Transverse Abdominis Activation Ratio between Healthy and Asymptomatic Low Back Pain Patients during Therapeutic Exercise
Authors: Gorbet Nathaniel , Selkow Noelle M. , Hart Joseph M. , Saliba Susan
Published: August 2010

Dysfunction of the transverse abdominis (TrA) has been associated with LBP. Several therapeutic exercises are prescribed to help target the TrA. Rehabilitative ultrasound imaging (RUSI) is used to capture activation of the TrA during exercise. The purpose was to examine TrA activation during the ADIM and quadruped exercises between healthy and nonsymptomatic LBP patients. We instructed the subjects how to perform the exercises and measured muscle thickness of the TrA at rest and during the exercises using RUSI. This allowed us to calculate TrA activation ratio during these exercises. We found no significant differences between activation ratios of the two groups during either exercise; however TrA activation during the ADIM was higher than the quadruped exercise. These exercises were capable of activating the TrA, which may be in part due to the verbal instruction they received. These exercises could be used during prevention or rehabilitation programs, since the TrA is activated.
Identification of Myocardial Damage in Systemic Sclerosis: A Nuclear Cardiology Approach
Authors: Nakajima Kenichi , Matsuo Shinro , Hasegawa Minoru , Kinuya Seigo , Takehara Kazuhiko
Published: August 2010

Myocardial involvement is an important prognostic factor in patients with systemic sclerosis, and early diagnosis and staging of the disease have been sought after. Since myocardial damage is characterized by connective tissue disease, including fibrosis and diffuse vascular lesions or microcirculation, nuclear myocardial perfusion imaging has been a promising option for evaluating myocardial damages in early stages. In addition to the conventional stress-rest perfusion imaging, the current use of quantitative electrocardiographic gated imaging has contributed to more precise evaluation of cardiac perfusion, ventricular wall motion, and diastolic function, all of which have enhanced diagnostic ability of evaluating myocardial dysfunction. Abnormal sympathetic imaging with Iodine-123 metaiodobenzylguanidine might be another option for identifying myocardial damage. This paper deals with approaches from nuclear cardiology to detect perfusion and functional abnormality as an early sign of myocardial involvement as well as possible prognostic values in patients with abnormal imaging results. The role of nuclear cardiology in the era of multiple imaging modalities is discussed.
Polyisoprene Nanoparticles Prepared by Polymerization in Microemulsion
Authors: Apolinar Y. , Ramos L. F. , Saade H. , Díaz de León R. , López R. G.
Published: August 2010

Batch polymerization of isoprene was carried out at 25∘C in a normal microemulsion stabilized with sodium dodecyl sulfate and initiated with the redox couple tert‐butyl hydroperoxide/tetraethylene‐pentamine. Characterization by transmission electronic microscopy showed that polyisoprene nanoparticles with number‐average diameter close to 20 nm were obtained. The low molecular weights obtained, as determined by gel permeation chromatography, were probably due to chain scission as inferred from the oxidative ambient at which polymerization was carried out. Microstructure calculated from infrared spectroscopy data indicates that the obtained polyisoprene contains around 80% total 1,4 units, which is in accordance with its glass transition temperature (−60.8∘C) determined by differential scanning calorimetry.
Short-Term Evaluation in Growing Rats of Diet ContainingBacillus thuringiensisCry1Ia12 Entomotoxin: Nutritional Responses and Some Safety Aspects
Authors: Guimarães Luciane Mourão , Farias Davi Felipe , Muchagata Relinda Campos Carvalho , de Magalhães Mariana Quezado , Campello Cláudio Cabral , Rocha Thales Lima , Vasconcelos Ilka Maria , Carvalho Ana Fontenele Urano , Mulinari Fernanda , Grossi-de-Sa Maria Fátima
Published: August 2010

The Cry1Ia12 entomotoxin from a BrazilianBacillus thuringiensisstrain is currently being expressed in cotton cultivars to confer resistance to insect-pests. The present study aimed to assess the effects of a diet containing Cry1Ia12 protein on growing rats. A test diet containing egg white and Cry1Ia12 (0.1% of total protein) as a protein source was offered to rats for ten days. In addition, an acute toxicity bioassay was performed in rats with a single oral dose of the entomotoxin (12 mg/animal). No adverse effects were observed in the animals receiving the test diet when compared to those receiving a control diet (egg white). The analysed parameters included relative dry weight of internal organs, duodenum histology, blood biochemistry, and nutritional parameters. The results of the acute toxicity test showed no mortality or behaviour alteration. Thus, Cry1Ia12 toxin at the tested concentration does not cause deleterious effects on growing rats when incorporated in the diet for 10 days.
Klein Tunneling of Light in Fiber Bragg Gratings
Authors: Longhi Stefano
Published: August 2010

A photonic analogue of Klein tunneling (KT), that is, of the exotic property of relativistic electrons to
pass a large repulsive and sharp potential step, is proposed for pulse propagation in a nonuniform
fiber Bragg grating with an embedded chirped region. KT can be simply observed as the opening of
a transmission window inside the grating stop band, provided that the impressed chirp is realized
over a length of the order of the analogue of the Compton wavelength.
Exact Solutions to KdV6 Equation by Using a New Approach of the Projective Riccati Equation Method
Authors: Gómez S Cesar A. , Salas Alvaro H. , Frias Bernardo Acevedo
Published: August 2010

We study a new integrable KdV6 equation from the point of view of its exact solutions by using an improved computational method. A new approach to the projective Riccati equations method is implemented and used to construct traveling wave solutions for a new integrable system, which is equivalent to KdV6 equation. Periodic and soliton solutions are formally derived. Finally, some conclusions are given.