bluuebunny/crossref_metadata_2025 huggingface dataset:
A graphical approach to assessing speech privacy and speech intrusion in offices
Authors: Conant David A.
Published: July 2012

Several very effective closed-form solutions for computing speech intelligibility and speech privacy have been available for designers since Kryters seminal work on articulation index (AI) in the early 1960s. Presented here is a unique graphical solution derived from many of these that lends itself remarkably well to visually assessing, for given room constants and source spectra, the relative contributions of noise insulation class and NC to both speech privacy and intrusion. A principal benefit of this graphical approach is the client’s much-improved grasp of the relative merits of current conditions versus alternate designs. Research faculty offices at MIT’s new Stata Center, presently in design by architect Frank O. Gehry, are discussed in a case study.
Acoustic identification of nine delphinid species in the eastern tropical Pacific Ocean
Authors: Oswald Julie N. , Barlow Jay , Norris Tom
Published: July 2012

Acoustic techniques have the potential to increase the reliability of cetacean species identification during shipboard surveys. The whistles of nine odontocete species were compared using data collected from a towed array and sonobuoys deployed during dolphin abundance surveys in the eastern tropical Pacific. Twelve variables were measured manually from spectrographic displays of each whistle (n=912). Multivariate discriminant function analysis (DFA) resulted in 49.9% of whistles being classified to the correct species. It was hypothesized that some whistles carry less species-specific information than others, therefore, groups of five whistles were averaged to reduce the effect of these ambiguous whistles. Correct classification increased to 65.4% when DFA was run on the averaged data set. A species identification decision tree that used 7 of the 12 whistle variables was constructed using nonparametric techniques (classification and regression trees) and resulted in 53.1% correct classification when applied to the original data set. Prior probabilities were added to the decision tree based on sighting rates for each species in the study area, resulting in 56.7% correct classification. The species identification decision tree provides a relatively simple acoustic method that can be used to augment conventional visual techniques.
Broadband barrel-stave flextensional transducers
Authors: Jones Dennis F.
Published: July 2012

Class III barrel-stave flextensional transducers are compact underwater sound sources that have broadband capabilities arising from close coupling between flexural and longitudinal vibrational modes. The electroacoustic performances of several of these transducers were measured at both the Defence Research Establishment Atlantic Acoustic Calibration Barge on Bedford Basin and the Seneca Lake Sonar Test Facility operated by the Naval Undersea Warfare Center Division Newport. Transmitting voltage response curves were obtained over the frequency range 0.5 to 20 kHz, and vertical directivity patterns at selected frequencies were plotted. A stress-limited source level of 204 dB//1μPa-m at 5 kHz was determined from high-power tests. Since the transducers were calibrated at water depths ranging from 15 to 107 m, the effects of hydrostatic pressure on the resonance frequencies were quantified. Recently, the Class III transducer was integrated into a battery-operated Broadband Acoustic Transmission System (BATS) which is currently being used for broadband sonar and marine mammal playback studies. A brief overview of the BATS hardware is presented. [Work supported in part by ONR.]
Analysis and optimal design and a class flextensional transducer
Authors: Roh Yongrae , Kang Kukjin
Published: July 2012

With the finite-element method, we analyzed variation of the sound pressure level and internal thermal distribution of a class flextensional transducer in relation to various design factors in its structures and material properties. The design factors included lengths of major and minor axes, thickness and height of a shell, length and width of a PZT stack, shape of an edge insert, thickness of a rubber coating, and all their material properties. Effects of each of the factors on the transducer performance were analyzed in a quantitative manner as a function of frequency. Based on the results, we determined the optimal structure of a class flextensional transducer that had 1-kHz resonance frequency, the maximum sound pressure level, and the minimum temperature rise in operation. The sound pressure by the optimal structure was higher than that of a basic structure by two times, and the temperature level in operation was lower by 20%. Results of the present work can be utilized to design class flextensional transducers of various resonance frequencies.
Finite scatterer volume corrections to multiple scattering theories
Authors: Photiadis Douglas
Published: July 2012

Multiple scattering theories used to describe random acoustic media usually assume the scatterers within the medium are pointlike and statistically independent from one another. The finite volume of the scatterers may, however, be relevant when the density of the scatterers is large. A general theoretical approach in the context of multiple scattering theory has been developed to account for this effect without introducing correlations between the scatterers. Employing this scheme, the effective wave speed, correlation length, and density of states have been evaluated for both two- and three-dimensional media and compared to point scatterer results. The corrections are found to be of the order of the fraction of the total volume occupied by the scatterers, and hence relevant to attempts to extend multiple scattering theories into the high density regime. Analytic results are obtained in both bulk acoustic and structural acoustic systems. [Research supported by ONR.]
Aircraft noise: Intolerability threshold of residents in a single-event-field study
Authors: Kastka Joachim , Faust Michael
Published: July 2012

Environmental aircraft noise of an airpath crossing a residential area is defined by single discrete flight events. The aim of this study was to examine if there is a threshold of intolerability of disturbance for overflight levels, measured in dB(A) Lmax of overflight events. Twenty-five residents living under an airpath at Duesseldorf Airport participated in a field study for 8 days. The only instruction given to the residents, living in their homes under natural conditions, their normal way of life, was to press a button on a small portable computer when an overflight event produced intolerable acute noise disturbance. Within the time period of 8 days, the airport produced 2400 overflights on the route leading over the area, mean Leq day (16 h) was 72 db(A). The noise was measured continuously in 1-s interval periods; the mean Lmax was 83 db(A), and 80% of all events were positioned between 74 and 92 dB(A) Lmax. For each flight event the mean intolerability reponse of the residents was computed; 22% of all events were evaluated as intolerable. A nonlinear positive accelerated function was found to best describe the relationship between single-event Lmax and intolerabilty response of residents to the noise events. Referring to this dose-response function, the threshold of intolerability defined by 10% intolerability responses is given by 74 dB(A) Lmax. Stevens power function and the loudness concept are discussed in the context of the results.
Organization of human auditory cortex
Authors: Moore Jean K.
Published: July 2012

An essential factor in stimulus processing within the auditory cortex is the horizontal transmission of information from one cortical subdivision to another. The importance of transcortical connections is underscored by the developmental pattern of the human auditory cortex. In ontogeny, maturation occurs in horizontal strata, first in the marginal layer, then in the afferent axons to the deeper cortical layers, and last in the commissural and association axons of the superficial cortical layers. Because direct tract tracing studies are not conducted in humans, information as to the direction and extent of transcortical information flow comes from studies of evoked activity and neuronal projections in subhuman primates. These primate studies have developed the core-belt-parabelt model of organization of auditory cortex, with further transmission from the parabelt region to such higher level processing areas as the dorsolateral frontal cortex and the superior temporal sulcus. This framework of information transmission developed in primates fits well with the results of imaging studies in humans. In this hierarchical system, an issue of interest is the level at which processing of speech stimuli conveyed through the auditory channel converges with processing of speech stimuli received through the visual channel.
Subjective threshold of sound strength (G) due to level changes in the early sound field: Preliminary results
Authors: Hyde Jerald R.
Published: July 2012

Acoustical measurements and related subjective studies over the past two decades have shown that increased early reflections produce increased sound strength, G in concert auditoria. The temporal distribution of early reflected sound and the role of room geometry have been found to be important design related factors relating to both G and acoustical intimacy, and therefore to hall quality in general [J. R. Hyde, Proc. 16th ICA, Seattle, Paper 1aAA3 (1998)]. A listening test was devised to determine the threshold of perception of changes in loudness relative to changes in the level of the early sound field. The test setup consisted of direct and single-delay speaker channels in a semi-anechoic room, using brief samples of different styles of symphonic music. Subjects were asked to choose the louder of two paired samples of the same musical passage, played in rapid succession. Preliminary results from ‘‘unsophisticated’’ test subjects indicate that the perception threshold of loudness difference occurs when the total sound strength G varies by 1.0 dB due to the addition of a single early reflection at about −6 dB. Details and results of the experiment will be presented, and ideas for future work and test procedures will be solicited.
Subjective preference of initial time delay gap in a Javanese gamelan concert hall
Authors: Sarwono J. , Lam Y. W.
Published: July 2012

Several human subjects were involved in a subjective test using the paired comparison method to determine the preferred initial time delay gap (ITDG) for listening to Javanese gamelan music (gendhing) in a concert hall. To provide comparisons, acoustic measurements in several pendopos in Indonesia have also been carried out. Pendopo is an open-sided hall, where the Javanese gamelan is usually played. The measurements were conducted using the room impulse response method, with a maximum length sequences (MLS) signal as its sound source. The ITDG of four pendopos are presented in this paper. The results of subjective preference testing showed that there are preferences for short ITDG, although evidence for a single value of preference was not conclusive. These results agree with the ITDG from the room responses measured in the pendopos, which are not common concert halls but open-sided halls.
Case studies of two performing arts halls
Authors: Conant David A. , McGraw Thomas J.
Published: July 2012

A new 1600-seat multipurpose hall in Mesa, Arizona and a 1200-seat music-only concert hall in Pocatello, Idaho were recently designed employing CATT-Acoustic and laser pointer modeling techniques to optimize room shapes and surface properties. Unique challenges included the correct modeling of a multitude of singly curved and doubly curved room surfaces in critical upper volumes. Acoustical design results of the halls, especially with regard to the CATT-Acoustic computer models, will be presented.
Acoustical characteristics of old wooden churches in Serbia
Authors: Mijic Miomir , Sumarac-Pavlovic Dragana
Published: July 2012

There are more than 50 churches in the central part of Serbia built entirely of wood. These churches were all built at the beginning of the 19th century. This paper presents the results of acoustical measurements conducted in these places of worship. In addition, the analysis of acoustical properties of different architectural styles and constructions within the same category of churches is presented.
A benchmark fast-field program model for infrasound propagation
Authors: Talmadge Carrick L. , Gilbert Kenneth E.
Published: July 2012

Three decades ago Pierce [e.g., Pierce, Posey, and Iliff, J. Geophys. Res. 76, 5025 (1971)] developed an exact theory for acoustic wave propagation in a temperature- and wind-stratified atmosphere. The theory includes both the acousto-gravity wave component (i.e., the Lamb wave) and the effect of a vector wind that can vary with height in both magnitude and direction. In this paper, a fast-field program (FFP) is discussed which numerically integrates Pierce’s differential equations, thus eliminating the need to approximate the solutions with a normal-mode expansion. For a stratified atmosphere, the FFP solution can serve as a benchmark for testing parabolic equation (PE) solutions that include the Lamb wave and a vector wind. Pierce’s theory is outlined and a general numerical approach is given for solving the fundamental equations of the theory. The numerical solutions are compared with known solutions obtained by other methods, such as the parabolic equation and analytic models. [Work supported by the U.S. Army Space and Missile Defense Command.]
Acoustic pulse propagation over laterally inhomogeneous ground
Authors: Albert Donald G.
Published: July 2012

Measurements were conducted outdoors over paths having areas with vastly different ground properties to investigate the effect of acoustic wave interaction with inhomogeneous ground conditions. Acoustic pulses with a bandwidth of approximately 10 to 500 Hz were produced by blank pistol shots, and were digitally recorded after propagating horizontal distances of 30 to 150 m. A natural snow cover was used to control the ground properties. The first measurement was conducted over an undisturbed snow cover, a highly porous material with low acoustic impedance. Then, portions of the snow cover were removed by plowing and the measurements repeated. By removing the snow, a less porous, higher impedance frozen ground surface was introduced into the propagation path. The snow cover was removed in stages so that several different inhomogeneous ground conditions were sampled, and a final measurement was made with the snow cover entirely removed. Changes in the pulse waveforms were observed when only a small proportion of the propagation path was modified by plowing. The measurement results will be compared with existing theories. [Work supported by U.S. Army.]
Nonlinear scattering of crossed ultrasonic pulsed beams in the presence of turbulence: Doppler shift and spectral broadening effects
Authors: Korman Murray S.
Published: July 2012

The nonlinear scattering of two finite-amplitude mutually perpendicular crossed beams—interacting in the presence of turbulence—generates a sum frequency component that radiates outside the interaction region [Korman and Beyer, J. Acoust. Soc. Am. 84, 339–349 (1988); 85, 611–620 (1989)]. Theoretical results are now extended to predict the angular dependence of Doppler shift and spectral broadening when the incident primary wave components are plane wave pulses instead of continuous waves. Lighthill’s equation is used to find the scattered density ρs(x,t) at the sum frequency. Modeling isotropic turbulence that is stationary, homogeneous, Gaussian, and ‘‘locally frozen,’’ one obtains the ensembled average Fourier spectrum 〈|ρs(x,ω)|2〉=B∫ ∫dω′ dω″|a1(ω′)|2×|a2(ω″)|2W(|ω|−ω′−ω″)ninjΦij(K), where B=(ω2ρ01ρ02m⋅n/c3ρ0x)2(2πcS/|m|), ρ01, ρ02, and ρ0 represent amplitudes and ambient density, n01, n02, and n are incident and scattered unit vectors, m=n01+n02, S=unit area, a1,2(ω)=Fourier amplitude spectrum for each primary pulse, K=(|ω|n−ω′n01−ω″n02)/c, W(ω)=(1/2πKσ)×exp[−(ω−K⋅U)2/2K2σ2], Φij(K) is the turbulence energy spectrum tensor and U, σ, and c are the mean, rms turbulent velocity, and sound speed, respectively.
English phoneme and word recognition by non-native English speakers as a function of spectral resolution and English experience
Authors: Padilla Monica , Shannon Robert V.
Published: July 2012

Phoneme, word, and sentence recognition was measured in listeners whose first language was either Chinese or Spanish, with varying degrees of English proficiency. Listeners were divided into four categories: (a) fully bilingual, (b) extensive English exposure after the age of 5, (c) extensive exposure between the ages of 12 and 18, and (d) extensive English exposure after the age of 18. Speech was presented at a level of 70 dB A. Listening conditions included noise (SNR of 15, 10, 5, 0 and −5 dB) and reduced spectral information (2, 4, 6, 8, and 16 frequency bands). The model of Boothroyd and Nittrouer [J. Acoust. Soc. Am. 84, 101–114 (1998)] was applied to the data to assess the relative contributions of phonemic and lexical processing as a function of language experience. Preliminary data show that non-native listeners had more difficulty understanding words, sentences, and vowels but only a slight disadvantage for consonants. Surprisingly, English experience had less effect on word and sentence recognition than on vowel recognition. Significantly lower performance on vowel recognition was seen even for fully bilingual listeners with reduced spectral resolution.
Neural processes underlying perception of the English /r/–/l/ contrast by native Japanese speakers before and after identification training: An fMRI study
Authors: Tajima Keiichi , Callan Daniel E. , Callan Akiko M. , Kubo Rieko , Akahane-Yamada Reiko , Koyama Sachiko , Masaki Shinobu
Published: July 2012

Neural processes underlying perception of difficult and easy English phonetic contrasts by native Japanese speakers are investigated using fMRI. Although difficult (/r/–/l/, /b/–/v/) and easy (/b/–/g/) contrasts likely involve similar neural processes, it is predicted that differences exist in specific brain regions (e.g., auditory association areas) as well as in functional connectivity underlying global brain processes involved with speech. We conducted feedback-based identification training of the /r/–/l/ contrast which has been shown to improve perceptual ability by Japanese [Lively et al., J. Acoust. Soc. Am. 96, 2076–2087 (1994)]. Improvements in perceptual ability are predicted to be marked by changes in the neural processes mentioned above. The /b/–/v/ contrast served as a control for which no perceptual training was given. Three experimental sessions were conducted: one for each of the contrasts. The stimuli consisted of 20 word pairs. Subjects were presented, via headphones, one stimulus every 7 s, during a 2-s silent interval between scans. A block design was employed in which five words were presented followed by five control stimuli (signal-correlated noise). The subjects’ task was to press a button to identify the phoneme perceived. Both fMRI and behavioral results are discussed in relation to the aforementioned predictions.
Investigating a computer-based method to measure school-age children’s ability to discriminate non-native speech contrasts
Authors: Pruitt Jesica C. , Pruitt John S. , Kuhl Patricia K. , Stevens Erica B.
Published: July 2012

Most studies of non-native speech perception have examined adult subject populations, as tests on infants, toddlers, and older children can be methodologically difficult to conduct. Direct application of methods used for adults in the assessment of children can be problematic. Such methods can be long, mentally fatiguing, and cognitively complex. In addition to task variables, stimuli which are difficult to perceive, such as non-native speech sounds, make such tests on children all the more difficult. The present study examines a new computer-based testing method specifically designed to test the discrimination of non-native speech sounds with 5- to 15-year-old children. The design uses an oddity task that presents non-native phoneme contrasts in a way that is engaging and motivating. For baseline comparison, discrimination data were obtained from 10 AE and 10 Hindi speaking adults using four phonetically different, natural CV Hindi speech contrasts and compared to identification data previously obtained from AE and Hindi adults using the same stimuli (Pruitt, 1995) implemented with a standard adult-testing protocol. Results from pilot testing with children and adults using this new computer-based method will be discussed and compared to the baseline identification and discrimination data. [Work supported by NICHD HD37954 to P. K. Kuhl.]
Influence of aging on perceptual learning of second-language phonetic contrasts
Authors: Kubo Rieko , Akahane-Yamada Reiko , Yamada Tsuneo
Published: July 2012

To examine the effect of aging on second-language (L2) learning, Japanese speakers of various ages, from 40s to 60s, were trained to identify American English /r/ and /l/ in a minimal pair identification task used in Lively et al. [J. Acoust. Soc. Am. 96, 2076–2087 (1994)]. Pretest–post-test design was administered in which the effect of the training was evaluated by the amount of improvement in accuracy from pretest to post-test. Surprisingly, most of the subjects, even in their 60s, improved significantly from pretest to post-test. When we analyzed the data by age group (40s, 50s, and 60s), each group improved 64% to 78%, 63% to 75%, and 61% to 64%, respectively, on average. In contrast, Yamada [J. Acoust. Soc. Am. 93, 4pSP8 (1993)] demonstrated that with the same training procedure of the same amount, Japanese adults around 20 years old improved from 60% to 85%, suggesting that the amount of improvement decreases by age. Taken together, we conclude that aging does interfere with the learning of new sounds, but not completely. Implications for the development of speech perception will be discussed.
New Paradigms in Type 2 Immunity
Authors: Pulendran Bali , Artis David
Published: July 2012

Insights into Type 2 Immunity

Different pathogens trigger characteristic immune responses. Although the immune responses against many bacteria, viruses, and fungi are relatively well understood, those against parasitic worms—termed type 2 responses—are much less so. Intriguingly, type 2 responses also mediate responses to allergens and allergic asthma.
Pulendran and Artis
(p.
431
) review progress in understanding the signals that trigger type 2 immunity and the cellular responses that these responses initiate.
Big Tobacco Indicts Itself
Golden Holocaust
Origins of the Cigarette Catastrophe and the Case for Abolition

by Robert N. Proctor

University of California Press, Berkeley, 2012. 772 pp. $49.95. £34.95. ISBN 9780520270169.
Authors: Brandon Thomas H.
Published: July 2012

Drawing on formerly secret industry records, Proctor explores how cigarettes became the most widely used drug on the planet—and argues for a ban on their manufacture and sale.
At Work to Save Lives
No Time to Lose
A Life in Pursuit of Deadly Viruses

by Peter Piot

Norton, New York, 2012. 415 pp. $28.95, C$31, £17.99. ISBN 9780393063165.
Authors: Tam Jerry C. H.
Published: July 2012

Piot's candid memoir of his path from early fieldwork on Ebola to founding director of UNAIDS highlights the challenges of "global health."
The Mind of a Male?
Authors: Chklovskii Dmitri B. , Bargmann Cornelia I.
Published: July 2012

A wiring diagram of neuronal circuits for mating behaviors in the male worm is anatomically reconstructed and analyzed.
HD6 Defensin Nanonets
Authors: Ouellette André J. , Selsted Michael E.
Published: July 2012

The human α-defensin 6 peptide fights infection in the human intestine by forming nanonets that entrap the microbial cells.
For China and Kazakhstan, No Meeting of the Minds on Water
Authors: Stone Richard
Published: July 2012

Kazakh scientists warn that low river flows from China could harm agriculture and aquatic ecosystems; bilateral talks are only treading water.
Protective Immunity Conferred by the C-Terminal Fragment of Recombinant Pasteurella multocida Toxin
Authors: Lee Jeongmin , Kang Hae-Eun , Woo Hee-Jong
Published: July 2012

Pasteurella multocidaserogroup D, producingP. multocidatoxin (PMT), is a causative pathogen of progressive atrophic rhinitis (PAR) in swine. To evaluate the protective immunity and vaccination efficacy of the truncated form of PMT, a C-terminal form of recombinant PMT (designated PMT2.3; amino acid residues 505 to 1285 of PMT) was expressed in anEscherichia coliexpression system, and the humoral and cellular immune responses to PMT2.3 were investigated. PMT2.3 vaccination in mice led to high levels of the anti-PMT antibody with a high neutralizing antibody titer. PMT2.3 also induced a cellular immune response to PMT, as demonstrated by the lymphocyte proliferation assay. Furthermore, strong protection against a homologous challenge withP. multocidawas also observed in mice vaccinated with PMT2.3. In PMT2.3 vaccination in swine, high levels of serum antibody titers were observed in offspring from sows vaccinated with PMT2.3. Offspring from sows vaccinated with PMT2.3 or toxoid showed a good growth performance as depicted by mean body weight at the time of sacrifice, as well as in average daily gain in the postweaning period. Low levels of pathological lesions in turbinate atrophy and pneumonia were also observed in these offspring. Therefore, we consider PMT2.3—in the truncated and nontoxic recombinant PMT form—to be an attractive candidate for a subunit vaccine against PAR induced byP. multocidainfection.
Characterization of a Therapeutic Model of Inhalational Anthrax Using an Increase in Body Temperature in New Zealand White Rabbits as a Trigger for Treatment
Authors: Comer Jason E. , Ray Bryan D. , Henning Lisa N. , Stark Gregory V. , Barnewall Roy E. , Mott Jason M. , Meister Gabriel T.
Published: July 2012

The development of an appropriate animal therapeutic model is essential to assess the potential efficacy of therapeutics for use in the event of a
Bacillus anthracis
exposure. We conducted a natural history study that showed New Zealand White rabbits exhibited a significant increase in body temperature (SIBT), changes in hematologic parameters, and increases in C-reactive protein and succumbed to disease with an average time to death of approximately 73 h following aerosol challenge with
B. anthracis
Ames spores. The SIBT was used as a trigger to treat with a fully human monoclonal antibody directed at protective antigen (PA). Ninety percent (9/10) of the treated rabbits survived the lethal inhalational challenge of
B. anthracis
. Further characterization investigated the protective window of opportunity for anti-PA antibody administration up to 12 h post-onset of SIBT. Eighty-three percent (5/6) of the rabbits treated at SIBT and 100% (6/6) of those treated at 6 h after SIBT survived challenge. Only 67% (4/6) of the rabbits treated at 12 h after SIBT survived. The increase in body temperature corresponded with both bacteremia and antigenemia (PA in the blood), indicating that SIBT is a suitable trigger to initiate treatment in a therapeutic model of inhalational anthrax.
A DNA-Based Candidate HIV Vaccine Delivered viaIn VivoElectroporation Induces CD4 Responses toward the α4β7-Binding V2 Loop of HIV gp120 in Healthy Volunteers
Authors: Kopycinski Jakub , Cheeseman Hannah , Ashraf Ambreen , Gill Dilbinder , Hayes Peter , Hannaman Drew , Gilmour Jill , Cox Josephine H. , Vasan Sandhya
Published: July 2012

Administration of a clade C/B′ candidate HIV-1 DNA vaccine, ADVAX, byin vivoelectroporation (EP) was safe and more immunogenic than intramuscular administration without EP. The breadth and specificity of T-cell responses to full-length Env were mapped. Responses to multiple Env regions were induced, with most focusing on V3/C4 and V2 regions, including the α4β7 integrin-binding domain. The breadth of responses induced by this DNA vaccine regimen was comparable to that of viral-vectored vaccine regimens.
Puberty is associated with increased deterioration of renal function in patients with CKD: data from the ItalKid Project
Authors: Ardissino Gianluigi , Testa Sara , Daccò Valeria , Paglialonga Fabio , Viganò Sara , Felice-Civitillo Cristina , Battaglino Francesco , Bettinelli Alberto , Bordugo Andrea , Cecchetti Valeria , De Pascale Salvatore , La Manna Angela , Li Volti Salvatore , Maringhini Silvio , Montini Giovanni , Pennesi Marco , Peratoner Leopoldo
Published: July 2012

Objective

To analyse the timing of end stage renal disease in children with chronic kidney disease (CKD).

Design

A population-based cohort study.

Setting

A nationwide registry (ItalKid Project) collecting information on all patients with CKD aged <20 years.

Patients

935 children with CKD secondary to renal hypodysplasia with or without urologic malformation. In a subgroup of patients (n=40) detailed pubertal staging was analysed in relation to CKD progression.

Main outcome measures

Kidney survival (KS) was estimated using renal replacement therapy (RRT) as the end-point. Puberty was staged by identifying the pubertal growth spurt.

Results

A non-linear decline in the probability of KS was observed, with a steep decrease during puberty: the probability of RRT was estimated to be 9.4% and 51.8% during the first and second decades of life, respectively. A break-point in the KS curve was identified at 11.6 and 10.9 years of age in male and female patients, respectively.

Conclusions

The present analysis suggests that puberty is associated with increased deterioration of renal function in CKD. The mechanism(s) underlying this unique and specific (to children) pattern of progression have not yet been identified, but it may be that sex hormones play a role in this puberty-related progression of CKD.
A rare but severe pulmonary side effect of cetuximab in two patients
Authors: Achermann Yvonne , Frauenfelder Thomas , Obrist Stefan , Zaugg Kathrin , Corti Natasha , Günthard Huldrych F
Published: July 2012

Cetuximab is a monoclonal antibody that treats malignant disease by inhibiting epidermal growth factor receptor. Many common adverse events have been reported and include skin rashes, infusion reactions, gastrointestinal complaints and headache. Up to now, cetuximab-associated pulmonary toxicity has been rarely reported in the literature. The present report describes two cases with probable interstitial pneumonitis 5–6 weeks after commencing treatment with chemotherapy combined with cetuximab. One patient recovered and the second patient died due to gastrointestinal bleeding 3 weeks after an initial response to steroids.
How reliable and safe is full-body low-dose radiography (LODOX Statscan) in detecting foreign bodies ingested by adults?
Authors: Mantokoudis Georgios , Hegner Simone , Dubach Patrick , Bonel Harald Marcel , Senn Pascal , Caversaccio Marco Domenico , Exadaktylos Aristomenis K
Published: July 2012

Objective

Foreign body ingestion is common and potentially lethal. This study evaluates the use of low-dose Statscans (LODOX) in emergency departments.

Design

This comparative cross-sectional study retrospectively assessed 28 289 digital chest x-rays and 2301 LODOX scans performed between 2006 and 2010 at a tertiary emergency centre. The radiographic appearance, image quality and location of ingested foreign bodies were evaluated in standard digital chest and LODOX radiography. The mean irradiation (μSv) and cumulative mean radiation dose per patient with the ingested foreign body were calculated according to literature-based data, together with the sensitivity and specificity for each modality.

Results

A total of 62 foreign bodies were detected in 39 patients, of whom 19 were investigated with LODOX and 20 with conventional digital chest radiography. Thirty-three foreign bodies were located in the two upper abdominal quadrants, 21 in the lower quadrants—which are not visible on conventional digital chest radiography—seven in the oesophagus and one in the bronchial system. The sensitivity and specificity of digital chest radiography were 44.4% and 94.1%, respectively, and for the LODOX Statscan 90% and 100%, respectively. The calculated mean radiation dose for LODOX investigations was 184 μS, compared with 524 μS for digital chest radiography.

Conclusions

LODOX Statscan is superior to digital chest radiography in the diagnostic work-up of ingested foreign bodies because it makes it possible to enlarge the field of view to the entire body, has higher sensitivity and specificity, and reduces the radiation dose by 65%.
Transport with ongoing resuscitation: a comparison between manual and mechanical compression
Authors: Gässler Holger , Ventzke Marc-Michael , Lampl Lorenz , Helm Matthias
Published: July 2012

Aim

In special circumstances it may be necessary to transport out-of-hospital cardiac arrest patients with ongoing resuscitation to the hospital. External mechanical chest compression devices could be an alternative for these resuscitations. The study compares manual chest compression with external mechanical devices and a semiautomatic device in transport conditions using a resuscitation manikin.

Methods

Manual chest compressions were compared with LUCAS 2, AutoPulse and animax mono devices using the Ambu Man Wireless MegaCode manikin (10 series each). The measurements were performed in a standard ambulance vehicle during transport on a predefined track of 5.0 km.

Results

Mean compression frequencies in the manual group (117±18 min−1) and in the animax mono group (115±10 min−1) were significantly higher than in the LUCAS 2 group (100 min−1, p=0.02) and the AutoPulse group (80 min−1, p<0.01). Both mechanical devices worked absolutely constantly. Only the animax mono group reached with 51.2 mm the recommended compression depth. The quality of manual compressions decreased considerably during braking or change manoeuvres while the mechanical devices continued to work constantly.

Conclusions

During a patient transport with ongoing resuscitation, external mechanical compression devices may be a good alternative to manual compression because they increase the safety of the rescuer and patient. Yet, in this study only animax mono reached the guideline specifications regarding chest compressions' frequency and depth. Concerning constancy, the mechanical devices work reliably and more independently from motion influences. Further studies are necessary to evaluate the effectiveness of these devices in patient transport.
Induction of a shorter compression phase is correlated with a deeper chest compression during metronome-guided cardiopulmonary resuscitation: a manikin study
Authors: Chung Tae Nyoung , Bae Jinkun , Kim Eui Chung , Cho Yun Kyung , You Je Sung , Choi Sung Wook , Kim Ok Jun
Published: July 2012

Objectives

Recent studies have shown that there may be an interaction between duty cycle and other factors related to the quality of chest compression. Duty cycle represents the fraction of compression phase. We aimed to investigate the effect of shorter compression phase on average chest compression depth during metronome-guided cardiopulmonary resuscitation.

Methods

Senior medical students performed 12 sets of chest compressions following the guiding sounds, with three down-stroke patterns (normal, fast and very fast) and four rates (80, 100, 120 and 140 compressions/min) in random sequence. Repeated-measures analysis of variance was used to compare the average chest compression depth and duty cycle among the trials.

Results

The average chest compression depth increased and the duty cycle decreased in a linear fashion as the down-stroke pattern shifted from normal to very fast (p<0.001 for both). Linear increase of average chest compression depth following the increase of the rate of chest compression was observed only with normal down-stroke pattern (p=0.004).

Conclusions

Induction of a shorter compression phase is correlated with a deeper chest compression during metronome-guided cardiopulmonary resuscitation.
Assignment problem in content distribution networks
Authors: Bateni Mohammadhossein , Hajiaghayi Mohammadtaghi
Published: July 2012

In a
Content Distribution Network (CDN)
, there are
m
servers storing the data; each of them has a specific bandwidth. All the requests from a particular client should be assigned to one server because of the routing protocol used. The goal is to minimize the total cost of these assignments—cost of each is proportional to the distance between the client and the server as well as the request size—while the load on each server is kept below its bandwidth limit. When each server also has a setup cost, this is an
unsplittable hard-capacitated facility location problem
. As much attention as facility location problems have received, there has been no nontrivial approximation algorithm when we have hard capacities (i.e., there can only be one copy of each facility whose capacity cannot be violated) and demands are unsplittable (i.e., all the demand from a client has to be assigned to a single facility). We observe it is NP-hard to approximate the cost to within any bounded factor in this case. Thus, for an arbitrary constant ϵ>0, we relax the capacities to a 1+ϵ factor. For the case where capacities are
almost uniform
, we give a bicriteria
O
(log
n
, 1+ϵ)-approximation algorithm for general metrics and a (1+ϵ, 1+ϵ)-approximation algorithm for tree metrics. A bicriteria (α,β)-approximation algorithm produces a solution of cost at most α times the optimum, while violating the capacities by no more than a β factor. We can get the same guarantees for nonuniform capacities if we allow quasipolynomial running time. In our algorithm, some clients
guess
the facility they are assigned to, and facilities
decide
the size of the clients they serve. A straightforward approach results in exponential running time. When costs do not satisfy metricity, we show that a 1.5 violation of capacities is necessary to obtain any approximation.

It is worth noting that our results generalize bin packing (zero connection costs and facility costs equal to one), knapsack (single facility with all costs being zero), minimum makespan scheduling for related machines (all connection costs being zero), and some facility location problems.
Santa claus meets hypergraph matchings
Authors: Asadpour Arash , Feige Uriel , Saberi Amin
Published: July 2012

We consider the restricted assignment version of the problem of max-min fair allocation of indivisible goods, also known as
the Santa Claus problem
. There are
m
items and
n
players. Every item has some nonnegative value, and every player is interested in only some of the items. The goal is to distribute the items to the players in a way that maximizes the minimum of the sum of the values of the items given to any player. It was previously shown via a nonconstructive proof that uses the Lovász local lemma that the integrality gap of a certain configuration LP for the problem is no worse than some (unspecified) constant. This gives a polynomial-time algorithm to estimate the optimum value of the problem within a constant factor, but does not provide a polynomial-time algorithm for finding a corresponding allocation.

We use a different approach to analyze the integrality gap. Our approach is based upon local search techniques for finding perfect matchings in certain classes of hypergraphs. As a result, we prove that the integrality gap of the configuration LP is no worse than 1/4. Our proof provides a local search algorithm which finds the corresponding allocation, but is nonconstructive in the sense that this algorithm is not known to converge to a local optimum in a polynomial number of steps.
Entropy, triangulation, and point location in planar subdivisions
Authors: Collette Sébastien , Dujmović Vida , Iacono John , Langerman Stefan , Morin Pat
Published: July 2012

A data structure is presented for point location in connected planar subdivisions when the distribution of queries is known in advance. The data structure has an expected query time that is within a constant factor of optimal. More specifically, an algorithm is presented that preprocesses a connected planar subdivision
G
of size
n
and a query distribution
D
to produce a point location data structure for
G
. The expected number of point-line comparisons performed by this data structure, when the queries are distributed according to
D
, is H˜ +
O
(H˜
1/2
+1) where H˜=H˜(
G,D
) is a lower bound on the expected number of point-line comparisons performed by any linear decision tree for point location in
G
under the query distribution
D
. The preprocessing algorithm runs in
O
(
n
log
n
) time and produces a data structure of size
O
(
n
). These results are obtained by creating a Steiner triangulation of
G
that has near-minimum entropy.
Improving differential evolution algorithm by synergizing different improvement mechanisms
Authors: Ali Musrrat , Pant Millie , Abraham Ajith
Published: July 2012

Differential Evolution (DE) is a well-known Evolutionary Algorithm (EA) for solving global optimization problems. Practical experiences, however, show that DE is vulnerable to problems like slow and/or premature convergence. In this article we propose a simple and modified DE framework, called MDE, which is a fusion of three recent modifications in DE: (1) Opposition-Based Learning (OBL); (2) tournament method for mutation; and (3) single population structure. These features have a specific role which helps in improving the performance of DE. While OBL helps in giving a good initial start to DE, the use of the tournament best base vector in the mutation phase helps in preserving the diversity. Finally the single population structure helps in faster convergence. Their synergized effect balances the exploitation and exploration capabilities of DE without compromising with the solution quality or the convergence rate. The proposed MDE is validated on a set of 25 standard benchmark problems, 7 nontraditional shifted benchmark functions proposed at the special session of CEC2008, and three engineering design problems. Numerical results and statistical analysis show that the proposed MDE is better than or at least comparable to the basic DE and several other state-of-the art DE variants.
First step towards automatic correction of firewall policy faults
Authors: Chen Fei , Liu Alex X. , Hwang Jeehyun , Xie Tao
Published: July 2012

Firewalls are critical components of network security and have been widely deployed for protecting private networks. A firewall determines whether to accept or discard a packet that passes through it based on its policy. However, most real-life firewalls have been plagued with policy faults, which either allow malicious traffic or block legitimate traffic. Due to the complexity of firewall policies, manually locating the faults of a firewall policy and further correcting them are difficult. Automatically correcting the faults of a firewall policy is an important and challenging problem. In this article, we first propose a fault model for firewall policies including five types of faults. For each type of fault, we present an automatic correction technique. Second, we propose the first systematic approach that employs these five techniques to automatically correct all or part of the misclassified packets of a faulty firewall policy. Third, we conducted extensive experiments to evaluate the effectiveness of our approach. Experimental results show that our approach is effective to correct a faulty firewall policy with three of these types of faults.
RelaxDHT
Authors: Legtchenko Sergey , Monnet Sébastien , Sens Pierre , Muller Gilles
Published: July 2012

DHT-based P2P systems provide a fault-tolerant and scalable means to store data blocks in a fully distributed way. Unfortunately, recent studies have shown that if connection/disconnection frequency is too high, data blocks may be lost. This is true for most of the current DHT-based systems' implementations. To deal with this problem, it is necessary to build more efficient replication and maintenance mechanisms. In this article, we study the effect of churn on PAST, an existing DHT-based P2P system. We then propose solutions to enhance churn tolerance and evaluate them through discrete event simulation.
Machine learning and algorithms; agile development
Authors: Langford John , Ortega Ruben
Published: July 2012

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

twitter

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

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

John Langford poses questions about the direction of research for machine learning and algorithms. Ruben Ortega shares lessons about agile development practices like Scrum.
Cosmic simulations
Authors: Kanipe Jeff
Published: July 2012

With the help of supercomputers, scientists are now able to create models of large-scale astronomical events.
Multitier programming in Hop
Authors: Serrano Manuel , Berry Gérard
Published: July 2012

A first step toward programming 21
st
-century applications.
The loss of location privacy in the cellular age
Authors: Wicker Stephen B.
Published: July 2012

How to have the best of location-based services while avoiding the growing threat to personal privacy.
Process mining
Authors: Van Der Aalst Wil
Published: July 2012

Using real event data to X-ray business processes helps ensure conformance between design and reality.
Quantum money
Authors: Aaronson Scott , Farhi Edward , Gosset David , Hassidim Avinatan , Kelner Jonathan , Lutomirski Andrew
Published: July 2012

Imagine money you can carry and spend without a trace.
Spreadsheet data manipulation using examples
Authors: Gulwani Sumit , Harris William R. , Singh Rishabh
Published: July 2012

Millions of computer end users need to perform tasks over large spreadsheet data, yet lack the programming knowledge to do such tasks automatically. We present a
programming by example
methodology that allows end users to automate such repetitive tasks. Our methodology involves designing a domain-specific language and developing a synthesis algorithm that can learn programs in that language from user-provided examples. We present instantiations of this methodology for particular domains of tasks: (a) syntactic transformations of strings using restricted forms of regular expressions, conditionals, and loops, (b) semantic transformations of strings involving lookup in relational tables, and (c) layout transformations on spreadsheet tables. We have implemented this technology as an add-in for the Microsoft Excel Spreadsheet system and have evaluated it successfully over several benchmarks picked from various Excel help forums.
The Underlying Event in Hadronic Collisions
Authors: Field Rick
Published: July 2012

I review studies of the underlying event (UE) in hadronic collisions, dating from the first CDF studies in 2000 to the latest LHC findings and surprises. I explain the CDF quantum chromodynamics (QCD) Monte Carlo model tunes and describe how well the Tevatron tunes did at predicting the behavior of the UE at the LHC. In a very short time, the LHC experiments collected a large amount of data at 900 GeV and 7 TeV that can be used to study the UE in great detail. I review the LHC UE results and compare them with one another, with the Tevatron results, and with some of the LHC QCD Monte Carlo model tunes. I also explain the relationship between minimum bias collisions and the UE and discuss new techniques for studying the UE (i.e., techniques beyond the traditional approach).