bluuebunny/crossref_metadata_2025 huggingface dataset:
Coat–protein–mediated resistance to tobacco mosaic virus: discovery mechanisms and exploitation
Authors: Beachy Roger N.
Published: July 2002

In 1986 we reported that transgenic plants which accumulate the coat protein of tobacco mosaic virus (TMV) are protected from infection by TMV, and by closely related tobamoviruses. The phenomenon is referred to as coat–protein–mediated resistance (CP–MR), and bears certain similarities to cross protection, a phenomenon described by plant pathologists early in this century. Our studies of CP–MR against TMV have demonstrated that transgenically expressed CP interferes with disassembly of TMV particles in the inoculated transgenic cell. However, there is little resistance to local, cell–to–cell spread of infection. CP–MR involves interaction between the transgenic CP and the CP of the challenge virus, and resistance to TMV is greater than to tobamoviruses that have CP genes more distantly related to the transgene. Using the known coordinates of the three–dimensional structure of TMV we developed mutant forms of CP that have stronger inter–subunit interactions, and confer increased levels of CP–MR compared with wild–type CP. Similarly, it is predicted that understanding the cellular and structural basis of CP–MR will lead to the development of variant CP transgenes that each can confer high levels of resistance against a range of tobamoviruses.
Investigating protein conformation–based inheritance and disease in yeast
Authors: Lindquist Susan , Krobitsch Sylvia , Li Liming , Sondheimer Neal
Published: July 2002

Our work supports the hypothesis that a protein can serve as an element of genetic inheritance. This protein–only mechanism of inheritance is propagated in much the same way as hypothesized for the transmission of the protein–only infectious agent in the spongiform encephalopathies; hence these protein factors have been called yeast prions. Our work has focused on [PSI+], a dominant cytoplasmically inherited factor that alters translational fidelity.This change in translation is produced by a self–perpetuating change in the conformation of the translation–termination factor, Sup35. Most recently, we have determined that new elements of genetic inheritance can be created by deliberate genetic engineering, opening prospects for new methods of manipulating heredity. We have also uncovered evidence that other previously unknown elements of protein–based inheritance are encoded in the yeast genome. Finally, we have begun to use yeast as a model system for studying human protein folding diseases, such as Huntington's disease. Proteins responsible for some of these diseases have properties uncannily similar to those that produce protein–based mechanisms of inheritance.
Structure of the 53BP1 BRCT region bound to p53 and its comparison to the Brca1 BRCT structure
Authors: Joo Woo S. , Jeffrey Philip D. , Cantor Sharon B. , Finnin Michael S. , Livingston David M. , Pavletich Nikola P.
Published: July 2002

Brca1 C-terminal (BRCT) domains are a common protein–protein interaction motif in proteins involved in the DNA damage response and DNA repair. The DNA-damage response protein 53BP1 has two BRCT domains that bind to the DNA-binding domain of p53. The 53BP1 tandem-BRCT region is homologous to the tandem-BRCT region of Brca1, which is involved in double-strand break repair and homologous recombination and which binds BACH1, a member of the DEAH helicase family. Here we report the structures of a human 53BP1–p53 complex and of the rat Brca1 BRCT repeats. The 53BP1–p53 structure shows that the two BRCT repeats are arranged tandemly and pack extensively through an interface that also involves the inter-repeat linker. The first BRCT repeat and the linker together bind p53 on a region that overlaps with the DNA-binding surface of p53 and involves p53 residues that are mutated in cancer and are important for DNA binding. Comparison with the structure of the tandem-BRCT region of Brca1 shows a remarkable conservation of the repeat arrangement and of the inter-BRCT repeat interface. Analysis of human BRCA1 tumor-derived mutations and conservation identifies a potential protein-binding site that we show through mutagenesis is involved in BACH1 binding. The BACH1-binding region of Brca1 consists of a unique insertion in the first BRCT repeat and the inter-repeat linker and is analogous to the region of 53BP1 that binds p53.
Quantitative analysis of factors affecting intraoperative precision and stability of optoelectronic and electromagnetic tracking systems
Authors: Wagner A. , Schicho K. , Birkfellner W. , Figl M. , Seemann R. , König F. , Kainberger Franz , Ewers R.
Published: July 2002

This study aims to provide a quantitative analysis of the factors affecting the actual precision and stability of optoelectronic and electromagnetic tracking systems in computer‐aided surgery under real clinical/intraoperative conditions. A “phantom‐skull” with five precisely determined reference distances between marker spheres is used for all measurements. Three optoelectronic and one electromagnetic tracking systems are included in this study. The experimental design is divided into three parts: (1) evaluation of serial‐ and multislice‐CT (computed tomography) images of the phantom‐skull for the precision of distance measurements by means of navigation software without a digitizer, (2) digitizer measurements under realistic intraoperative conditions with the factors OR‐lamp (radiating into the field of view of the digitizer) or/and “handling with ferromagnetic surgical instruments” (in the field of view of the digitizer) and (3) “point‐measurements” to analyze the influence of changes in the angle of inclination of the stylus axis. Deviations between reference distances and measured values are statistically investigated by means of analysis of variance. Computerized measurements of distances based on serial‐CT data were more precise than based on multislice‐CT data. All tracking systems included in this study proved to be considerably less precise under realistic OR conditions when compared to the technical specifications in the manuals of the systems. Changes in the angle of inclination of the stylus axis resulted in deviations of up to 3.40 mm (mean deviations for all systems ranging from 0.49 to 1.42 mm, variances ranging from 0.09 to 1.44 mm), indicating a strong need for improvements of stylus design. The electromagnetic tracking system investigated in this study was not significantly affected by small ferromagnetic surgical instruments.
Dissipation, fluctuations, and conservation laws
Authors: Grassia Paul
Published: July 2002

A large particle moves through a sea of small particles. On the microscale, all particle collisions are elastic. However, on the macroscale, where only the large particle is properly resolved, dissipative forces and fluctuating random forces are observed. These forces are connected by a fluctuation–dissipation theorem proved in two different ways, first via statistical mechanics, and second from fundamental classical mechanical principles of momentum and energy conservation. The novel classical mechanics proof elucidates the relation between micro- and macroscale behaviors, and offers new insights into the physics behind the fluctuation–dissipation result.
Atomic polarization visualized
Authors: Rochester S. M. , Budker D.
Published: July 2002

A method of visualizing atomic polarization as a surface in three dimensions is described. The technique is used to illustrate the evolution of polarized atoms in external electric and magnetic fields. This can aid in the understanding of experiments involving the evolution of atomic polarization, such as optical rotation experiments and measurements of discrete symmetry violations in atomic systems.
Paradigms in Physics: A new upper-division curriculum
Authors: Manogue Corinne A. , Siemens Philip J. , Tate Janet , Browne Kerry , Niess Margaret L. , Wolfer Adam J.
Published: July 2002

We describe a new curriculum for the final two years of a B.S. program in Physics. Case studies in the junior year provide concrete examples or Paradigms as pillars to support systematic Capstone lectures in the senior year. In each of nine three-week Paradigms, the junior progresses from a descriptive lower-division understanding to an advanced analysis of a topic defined by phenomenon rather than discipline. Students generally view the new format with favor. They are better at visualization and make important connections among physics disciplines. Independent assessment is ongoing.
The mystery of the quantum cakes
Authors: Kwiat P. G. , Hardy L.
Published: July 2002

In an attempt to make the concept and consequences of quantum mechanical entanglement more accessible to the non-physicist, we present a simple “real-world” explanation of the proof of quantum mechanical nonlocality without the use of inequalities.
On approximating guided waves in plates with thin anisotropic coatings by means of effective boundary conditions
Authors: Niklasson A. Jonas , Datta Subhendu K. , Dunn Martin L.
Published: July 2002

In this paper, effective boundary conditions for elastic wave propagation in plates with thin coatings are derived. These effective boundary conditions are used to obtain an approximate dispersion relation for guided waves in an isotropic plate with thin anisotropic coating layers. The accuracy of the effective boundary conditions is investigated numerically by comparison with exact solutions for two different material systems. The systems considered consist of a metallic core with thin superconducting coatings. It is shown that for wavelengths long compared to the coating thickness there is excellent agreement between the approximate and exact solutions for both systems. Furthermore, numerical results presented might be used to characterize coating properties by ultrasonic techniques.
Linear prediction coding analysis and self-organizing feature map as tools to classify stress calls of domestic pigs (Sus scrofa)
Authors: Schön Peter-Christian , Puppe Birger , Manteuffel Gerhard
Published: July 2002

It is assumed that calls may give information about the inner (emotional) state of an animal. Hence, in the last years sound analysis has become an increasingly important tool for the interpretation of the behavior, the health condition, and the well-being of animals. A procedure was developed that allows the characterization, classification, and visualization of the cluster structures of stress calls of domestic pigs (Sus scrofa). Based on the acoustic model of the sound production the extraction of features from calls was performed with linear prediction coding (LPC). A vector-based self-organizing neuronal network was trained with the determined LPC coefficients, resulting in a feature map. The cluster structure of the calls was then visualized with a unified matrix and the neurons were labeled for their input origin. The basic applicability of the procedure was tested by using two examples which were of special interest for a possible evaluation of the normal farming practice. The procedure worked well both in discriminating individual piglets by their scream characteristics and in classifying pig stress calls vs other calls and noise occurring under normal farming conditions.
Social survey of community response to a step change in aircraft noise exposure
Authors: Fidell Sanford , Silvati Laura , Haboly Edward
Published: July 2002

Community response to a step change in aircraft noise exposure associated with the opening of a new runway at Vancouver International Airport was documented in two rounds of telephone interviews. One round of interviews was conducted 15 months prior to the start of operations on the new runway, while a second round of interviews was undertaken 21 months after the start of operations. The proportion of respondents who described themselves as “very” or “extremely” annoyed by aircraft noise in a residential area with increased aircraft noise exposure after the runway opening was markedly greater than that predictable from well-known dosage–response relationships. Analysis suggests that a good part of the “excess” annoyance is attributable to the net influence of nonacoustic factors.
Recognition of low-pass-filtered consonants in noise with normal and impaired high-frequency hearing
Authors: Horwitz Amy R. , Dubno Judy R. , Ahlstrom Jayne B.
Published: July 2002

People with high-frequency hearing loss often complain of difficulty understanding speech, particularly in noisy environments. The reduction in audible high-frequency speech information provides one explanation. In addition, high-frequency hearing loss may reduce the contribution from the “tails” of high-frequency auditory nerve fibers, resulting in diminished availability of lower frequency speech cues. This study was designed to determine if high-frequency hearing loss results in speech-understanding deficits beyond those accounted for by reduced high-frequency speech information. Recognition of speech, both low-pass filtered and unfiltered, was measured for subjects with normal hearing and those with hearing loss limited to high frequencies. Nonsense syllables were presented in three levels of noise that was spectrally shaped to match the long-term spectrum of the speech. Scores for subjects with impaired high-frequency hearing were significantly poorer than scores for subjects with normal hearing. In the case of the low-pass-filtered speech, performance differences between groups could not be attributed to differences in speech audibility, as high-frequency speech cues were absent for all subjects. These results are consistent with the hypothesis that high-frequency fibers encode useful low-frequency speech information.
A new hybrid passive–active noise absorption system
Authors: Beyene Samson , Burdisso Ricardo A.
Published: July 2002

A new hybrid passive–active system is developed for sound absorption over a wide frequency range. The system is comprised of a layer of absorbing material positioned at a distance from an active wall, leaving an air space. The motion of the active wall is based on a new control approach which consists of the minimization of the reflected wave within the airspace which modifies the layer’s back surface impedance so as to match the characteristic impedance of air. This technique is referred here as inducing an impedance-matching condition. Both numerical and experimental results of such a system are presented for normally incident planar waves. The hybrid passive–active system results in a high absorption coefficient of 0.8–1.0 over the frequency range 100–2000 Hz and is insensitive to system parameters such as air space depth and absorbing layer thickness.
Capped ceramic underwater sound projector
Authors: Tressler James F. , Cao Wenwu , Uchino Kenji , Newnham Robert E. , Hughes W. Jack
Published: July 2002

The cymbal-type transducer developed at the Materials Research Laboratory at Penn State Univ., which is similar to the ring/shell flextensional transducer, is currently being investigated as a shallow-water (<250 m) sound projector for the 10–75 kHz frequency range. The standard size cymbal transducer is 12.7 mm in diameter and approximately 2 mm in total thickness. It consists of a poled lead zirconate-titanate (PZT) disk capped symmetrically on each face by identical thin metal caps. Each cap is shaped with a cavity on its inner surface so that an air space exists between the PZT disk and the top of the cap. The size of the air space, the thickness of the cap, and the type of cap material all influence the operating performance and allowable operating depth of the device. Parameters necessary to characterize an underwater projector such as resonance frequency, mechanical Q, electroacoustic efficiency, transmit voltage response (TVR), and source level will be presented. Experimental data will be compared with values calculated from the Ansys■ finite-element program. Results from single elements as well as cymbal arrays (both potted and unpotted) will be shown. [This work was funded by the Office of Naval Research Contract No. N00014-96-1-1173.]
Sound-speed measurements in the surface-wave layer
Authors: Terrill Eric , Melville W. Kendall
Published: July 2002

Wave breaking at the surface of the ocean entrains bubbles, significantly modifying the phase speed and attenuation of acoustic waves propagating through the resulting two-phase medium. An autonomous buoy system was developed that directly measures sound speed at 3.33, 5, and 10 kHz at seven depths ranging from 0.7 to 7 m through the use of a travel-time technique. Simultaneous measurements at each depth are obtained at a 2-Hz rate, allowing observation of the unsteady sound-speed field from individual bubble injection events, as well as the calculation of mean sound speeds. The travel-time technique allows a direct measurement of the sound speed, eliminating the uncertainties common with inferring sound speeds from bubble population data. The sound speed buoy was deployed in the North Atlantic during the winter of 1993–94 as part of the Acoustic Surface Reverberation Experiment (ASREX). Our aim was to characterize the highly variable near-surface sound-speed field under varying environmental conditions. Forty-three days of data were obtained spanning several storm cycles with wind speeds and significant wave heights reaching 20 m/s and 8 m, respectively. During periods of intense wave breaking, average sound speeds below 1000 m/s were observed at the 0.7-m measurement depth while instantaneous sound speeds during individual events approached values as low as 300 m/s. Furthermore, the data suggest that the dispersive effects of bubbles may extend to frequencies as low as 5 kHz near the surface during storms. Strong correlations of the mean and rms sound speed with the overlying wind and wave fields were found.
Effects of stapedius-muscle contractions on the masking of auditory-nerve responses
Authors: Pang Xiao Dong , Guinan John J.
Published: July 2002

There has been little exploration of the mechanisms by which stapedius muscle contractions reduce the masking of responses to high-frequency sounds by low-frequency sounds. To fill this gap in knowledge, controlled stapedius contractions were elicited with direct shocks in anesthetized cats, and measurements were made of the effects of these contractions on the masking of single auditory-nerve fibers and on the attenuation of middle-ear transmission. The results show that the stapedius-induced reductions of masking can be much larger than the attenuations of low-frequency sound. With a 300-Hz band of masking noise centered at 500 Hz, and signal tones at 6 or 8 kHz, unmasking effects over 40 dB were observed for sounds 100 dB SPL or less. The data suggest that much larger unmasking might occur. The observed unmasking can be explained completely by a linear stapedius-induced attenuation of sound transmission through the middle ear and a nonlinear growth rate of masking for auditory-nerve fibers. No central effects are required. It is argued that the reduction of the upward spread of masking is probably one of the most important functions of the stapedius muscle.
Frequency specificity of the human auditory brainstem and middle latency responses to brief tones. II. Derived response analyses
Authors: Oates Peggy , Stapells David R.
Published: July 2002

This study investigated the frequency specificity of the auditory brainstem (ABR) and middle latency (MLR) responses to 500- and 2000-Hz brief tones using narrow-band derived response analyses of the responses recorded in high-pass masking noise [Oates and Stapells, J. Acoust. Soc. Am. 102, 3597–3608 (1997)]. Stimuli were linear- and exact-Blackman-gated tones presented at 80 dB ppe SPI. Cochlear contributions to ABR wave V-V′ and MLR wave Na-Pa were assessed by response amplitude profiles as a function of derived band center frequency. The largest amplitudes of waves V and Na-Pa occurred in the 500- and 707-Hz derived bands in response to the exact-Blackman- and linear-gated 500-Hz tones. The peak in the response amplitude profiles for wave V to both 2000-Hz stimuli was seen in the 2000-Hz derived band. For wave Na-Pa, the maxima in the amplitude profiles occurred in the 2000- and 1410-Hz derived bands for the exact-Blackman- and linear-gated tones. Smaller cochlear contributions to the ABR/MLR were also present at 0.5–1 octave above and below the nominal stimulus frequencies. The ABR/MLR to 500- and 2000-Hz 80 dB ppe SPL tones thus shows good frequency specificity, with no significant differences in the frequency specificity of: (1) ABR versus MLR; (2) these evoked potentials to 500- versus 2000-Hz tones; and (3) responses to exact-Blackman- versus linear-gated tones.
Ripple density resolution for various rippled-noise patterns
Authors: Supin Alexander Ya. , Popov Vladimir V. , Milekhina Olga N. , Tarakanov Mikhail B.
Published: July 2002

Ripple-density resolution was measured in normal humans using rippled noise with a phase-reversal test. The principle of the test was to find the highest ripple density at which an interchange of spectral peak and trough positions (the phase reversal) is detectable. Different rippled noise patterns were used: (i) either frequency-proportional or constant ripple spacing; (ii) various bandwidth; and (iii) either steep or shallow slopes of the spectrum envelope. When tested with frequency-proportional rippled noise, ripple-density resolution as expressed in relative units (the center frequency to ripple spacing ratio) little depended on frequency within a range of 1 to 8 kHz: from 11.4 at 1 kHz to 14.9 at 8 kHz, mean 13.1. These values were virtually independent on noise bandwidth. When tested with constant ripple spacing, the resolution was of similar values taking the relative ripple density at the lower part of the passband. Being measured by noise with steep spectral edges, the resolution was five units higher than it was for shallow-enveloped spectra, thus suggesting some edge effects at the spectrum boundaries. The resolution values obtained were about twice higher than those predicted by peripheral auditory filter tuning.
Correlated amplitude fluctuations of spontaneous otoacoustic emissions in six lizard species
Authors: van Dijk Pim , Manley Geoffrey A. , Gallo Lothar
Published: July 2002

Spontaneous otoacoustic emissions were recorded from 17 lizard ears (six species: Gerrhosaurus major, Iguana iguana, Basiliscus vittatus, Tupinambis teguixin, Varanus exanthematicus, and Cordylus tropidosternum). The spectrum of each recording contained multiple spectral peaks. For each peak, the envelope cross-correlation R(τ) with all other peaks from the same ear was computed. Of the total of 346 emission peak pairs, 58 (17%) showed a significant correlation. Thus like in humans, multiple emission peaks in lizards frequently interact. In the lizards, the cross-correlation was positive in 30 cases, and negative in 28 cases. The cross-correlation function peaked at either a positive (τpeak>0) or a negative (τpeak<0) delay time. Peak delays ranged from −3.7 ms to 6.2 ms with an average 0.2 ms (s.d. 1.8 ms). The range of observed peak delay values differs from that in human [average τpeak=11.0 ms (s.d. 22.1 ms)].
Acoustic investigation of objects in shallow water using FEM and BEM
Authors: von Estorff Otto
Published: July 2002

The acoustic behavior of a submerged object is strongly influenced by the existence of reflecting boundaries, namely the water surface or the bottom. Only in some rare cases can it be assumed that the water region is ‘‘infinite.’’ The present paper is related to the investigation of underwater objects in shallow water by means of numerical methods. These must be able to take into account fluid/structure interaction effects as well as different boundary conditions. In the suggested methodology, displacement-based finite elements for the structure are coupled to acoustic boundary elements for the fluid medium. An underwater plate and a submerged cylinder will be investigated in different parametric studies. It will be shown how the boundaries (surface, bottom) can be taken into account, and in which cases the effect of boundaries could be neglected. Moreover, the required computational resources as well as the applicability of different methods will be discussed.
Comparisons between computer simulations of room acoustical parameters and those measured in concert halls
Authors: Rindel Jens Holger , Shiokawa Hiroyoshi , Christensen Claus Lynge , Gade Anders Christian
Published: July 2002

A number of European concert halls were surveyed in 1989. In this paper comparisons are made between measured room acoustical parameters and those obtained from computer simulations on concert halls using the odeon program version 3.1. The key parameter compared with measured data is the reverberation time, and this is mainly used to adjust the absorption data of the surfaces in the computer model. But five additional parameters are calculated and compared with measured data as well. In order to determine the sensitivity of the computer model, comparisons are also made between the results obtained from computer simulations using models with a high geometrical fidelity and those from models with simplifications to geometry that are in better agreement with the laws of high-frequency modeling.
Effects of subglottal pressure variation on professional baritone singers’ voice sources
Authors: Sundberg Johan , Andersson Maria , Hultqvist Clara
Published: July 2002

Five professional operatic baritone singers’ voice-source characteristics were analyzed by means of inverse filtering of the flow signal as captured by a flow mask. The subjects sang a long sustained diminuendo, from loudest to softest, three times on the vowels [a:] and [æ:] at fundamental frequencies representing 25%, 50%, and 75% of their total pitch range as measured in semitones. During the diminuendos, they repeatedly inserted the consonant [p] so that associated subglottal pressures could be estimated from the oral pressure during the p-occlusions. Pooling the three takes of each condition, ten subglottal pressures, equidistantly spaced between highest and lowest, were selected for analysis. Sound-pressure levels (SPL), peak-to-peak glottal airflow, maximum flow declination rate, closed quotient, glottal dc flow, and the level difference between the two lowest partials of the source spectrum (H1–H2) were determined. All parameters except the glottal dc flow showed a systematic variation with subglottal pressure or the fractional excess pressure over threshold. The results are given in terms of equations representing the average across subjects for the relation between subglottal pressure and each of the mentioned voice-source parameters.
The estimation of signal-to-noise ratio in continuous speech for disordered voices
Authors: Qi Yingyong , Hillman Robert E. , Milstein Claudio
Published: July 2002

Presented is a method of estimating the signal-to-noise ratio (SNR) of continuous utterances for patients with various types of voice disorders that ranged in severity of dysphonia from mild to severe. The SNR is estimated based on the residual that is left after systematically removing the short- and long-term correlations that exist in the speech signal. Results indicate that the SNR is consistent with human perceptual judgments, particularly those that consistently differentiate close-to-normal versus highly disphonic voices.
Formants of children, women, and men: The effects of vocal intensity variation
Authors: Huber Jessica E. , Stathopoulos Elaine T. , Curione Gina M. , Ash Theresa A. , Johnson Kenneth
Published: July 2002

The purpose of this study was to investigate the formant frequencies and amplitudes of a wide age range of children and one group of adults at three sound pressure levels (SPLs). Subjects were ten females and ten males in the following age groups (in years): 4, 6, 8, 10, 12, 14, 16, 18, and adults. A sustained /ɑ/ was produced three times by each subject. Formant frequencies were obtained using linear predictive coding analysis. Formant amplitudes were measured from the highest amplitude harmonic in the area of each formant. In addition to following established trends previously published in other studies, it was hypothesized that the first formant frequency would increase with increasing intensity, that females would have higher formant frequencies than same aged males, and that women and children would have reduced formant amplitudes as compared to men. It was found that first formant frequency increased with intensity and changed as a function of age and sex. Second and third formant frequencies changed with age and sex. Formant amplitudes followed the trends set by the SPL differences and did not change as a function of age and sex. Results are discussed in terms of anatomic differences and SPL.
Transmission beam pattern and echolocation signals of a harbor porpoise (Phocoena phocoena)
Authors: Au Whitlow W. L. , Kastelein Ronald A. , Rippe Tineke , Schooneman Nicole M.
Published: July 2002

The transmission beam pattern of an echolocating harbor porpoise (Phocoena phocoena) was measured in both the vertical and horizontal planes. An array of seven Brüel and Kjaer 8103 hydrophones connected to an amplifier-line driver module was used to measure the beam patterns. The porpoise was trained to station in a hoop and echolocate a cylindrical target located at a range between 7 and 9 m while the array was located 2 m in front of the hoop. The 3-dB beamwidth in both the vertical and horizontal planes was the same at approximately 16 degrees and the beam was pointed toward the forward direction. The individual hydrophones in both the vertical and horizontal arrays measured signal waveforms that were similar throughout the 40-degree span of the array. The porpoise emitted signals with intervals that were 20 to 35 ms longer than the round trip travel time between the animal and the target. The average source level, peak frequency, and bandwidth were 157 dB, 128 kHz, and 16 kHz, respectively.
Limitations in using Golay codes for head-related transfer function measurement
Authors: Zahorik Pavel
Published: July 2002

Although the use of Golay codes has been recommended for measuring external-ear impulse responses [Zhou et al., J. Acoust. Soc. Am. 92, 1169–1171 (1992)], this report demonstrates a potential limitation that could arise in applications requiring probe stimulus excitation to last longer than a few hundreds of milliseconds. In such situations, artifacts in the measured impulse responses can result from using Golay codes if the system under evaluation is time variant. These impulse-response artifacts are demonstrated for measurements of human binaural impulse responses (equivalent to head-related transfer functions, or HRTFs) under conditions analogous to small head movements during the measurement procedure. A popular alternative impulse-response measurement technique using maximum-length sequences (MLSs) does not produce artifact-contaminated measurements under the same conditions.
The multipass rheometer
Authors: Mackley M. R. , Marshall R. T. J. , Smeulders J. B. A. F.
Published: July 2002

This article describes the technical performance and initial results for a new, two-piston, ‘‘multipass rheometer.’’ Fluid is contained within a capillary by two servo-hydraulically controlled pistons. Both steady flow and oscillatory data can be obtained from the device with mean pressure as an independent adjustable variable. Steady and oscillatory data are presented for a silicone oil and a viscoelastic solution and certain data are compared with results obtained from a Rheometrics RDS-II mechanical spectrometer or with literature data. The results show that the multipass rheometer is capable of extending the experimental ranges of many conventional rheometers, particularly in terms of pressure control, high shear rates, and multiple, successive flow measurements.
Reporting of Race and Hispanic Ethnicity in Breast Cancer Studies From the National Cancer Database
Authors: Bazan Jose G. , Obeng-Gyasi Samilia , Gamez Mauricio E.
Published: August 2022

This cohort study characterizes the inclusion of Hispanic ethnicity or ethnoracial categories in breast cancer studies from the National Cancer Database.
Association of PD-L1 Expression and Other Variables With Benefit From Immune Checkpoint Inhibition in Advanced Gastroesophageal Cancer
Authors: Yoon Harry H. , Jin Zhaohui , Kour Oudom , Kankeu Fonkoua Lionel Aurelien , Shitara Kohei , Gibson Michael K. , Prokop Larry J. , Moehler Markus , Kang Yoon-Koo , Shi Qian , Ajani Jaffer A.
Published: August 2022

Importance

Approval by the US Food and Drug Administration of immune checkpoint inhibition (ICI) for advanced gastroesophageal cancer (aGEC) irrespective of PD-L1 status has generated controversy. Exploratory analyses from individual trials indicate a lack of meaningful benefit from ICI in patients with absent or low PD-L1 expression; however, analysis of a single variable while ignoring others may not consider the instability inherent in exploratory analyses.

Objective

To systematically examine the predictive value of tissue-based PD-L1 status compared with that of other variables for ICI benefit in aGEC to assess its stability.

Data Sources

MEDLINE, Embase, Scopus, Web of Science, Cochrane Central Register (2000-2022).

Study Selection, Data Extraction, and Synthesis

Randomized clinical trials (RCTs) were included of adults with aGEC (adenocarcinoma [AC] or squamous cell carcinoma [SCC]) randomized to anti−PD-1 or PD-L1−containing treatment vs standard of care (SOC). Study screening, data abstraction, and bias assessment were completed independently by 2 reviewers. Of 5752 records screened, 26 were assessed for eligibility; 17 trials were included in the analysis.

Main Outcomes and Measures

The prespecified primary end point was overall survival. The mean hazard ratio (HR) for ICI vs SOC was calculated (random-effects model). Predictive values were quantified by calculating the ratio of mean HRs between 2 levels of each variable.

Results

In all, 17 RCTs (9 first line, 8 after first line) at low risk of bias and 14 predictive variables were included, totaling 11 166 participants (5067 with SCC, 6099 with ACC; 77.6% were male and 22.4% were female; 59.5% of patients were younger than 65 years, 40.5% were 65 years or older). Among patients with SCCs, PD-L1 tumor proportion score (TPS) was the strongest predictor of ICI benefit (HR, 0.60 [95% CI, 0.53-0.68] for high TPS; and HR, 0.84 [95% CI, 0.75-0.95] for low TPS), yielding a predictive value of 41.0% favoring high TPS (vs ≤16.0% for other variables). Among patients with AC, PD-L1 combined positive score (CPS) was the strongest predictor (after microsatellite instability high status) of ICI benefit (HR, 0.73 [95% CI, 0.66-0.81] for high CPS; and HR, 0.95 [95% CI, 0.84-1.07] for low CPS), yielding a predictive value of 29.4% favoring CPS-high (vs ≤12.9% for other variables). Head-to-head analyses of trials containing both levels of a variable and/or having similar design generally yielded consistent results.

Conclusions and Relevance

Tissue-based PD-L1 expression, more than any variable other than microsatellite instability-high, identified varying degrees of benefit from ICI-containing therapy vs SOC among patients with aGEC in 17 RCTs.
Association of Neoadjuvant Pembrolizumab for Oral Cavity Squamous Cell Carcinoma With Adverse Events After Surgery in Treatment-Naive Patients
Authors: Tang Alice L. , O’Neil Thomas , McDermott Sean , Tripathi Siddhant , Tikhtman Raisa , Mark Jonathan R. , Patil Yash , Tabangin Meredith , Altaye Mekibib , Wise-Draper Trisha M. , Zender Chad A.
Published: August 2022

Importance

Pembrolizumab, a monoclonal antibody targeting programmed cell death 1, is currently approved by the US Food and Drug Administration for recurrent or metastatic head and neck squamous cell carcinoma (HNSCC). The potential neoadjuvant role of programmed cell death 1 inhibitors in primary surgical management of HNSCC and effects on surgical outcomes are poorly understood.

Objective

To evaluate the incidence of postoperative adverse events in treatment-naive patients with advanced oral cavity cancer receiving neoadjuvant pembrolizumab when compared with matched controls, as part of a window-of-opportunity multi-institutional clinical trial assessing neoadjuvant pembrolizumab for locally advanced HNSCC.

Design, Setting, and Participants

This retrospective cohort study at a single tertiary academic institution included treatment-naive patients with local regionally advanced oral cavity squamous cell carcinoma (OCSCC) who were undergoing surgical resection.

Exposures

Patients with local regionally advanced resectable OCSCC who received neoadjuvant pembrolizumab were retrospectively reviewed for postoperative adverse events. Controls were matched by age, race, smoking status, and overall cancer stage based on historical data at the same institution. Matched-cohort analysis was performed using a McNemar test to assess differences between the groups.

Main Outcomes and Measures

Incidence of adverse events following surgical resection of advanced OCSCC within 30 days of surgery and on continued follow-up.

Results

A total of 64 patients (32 as part of the prospective clinical trial and 32 as controls; mean [SD] age, 59.6 [10.3] years; 28 [44%] women) were included in the analysis. Postoperative adverse events in the 32 patients receiving pembrolizumab included lymphedema (n = 20 [63%]), trismus (n = 7 [22%]), return to operating room (n = 7 [22%]), wound infection (n = 7 [22%]), fistula (n = 6 [19%]), wound dehiscence (n = 4 [13%]), flap failure (n = 3 [9%]), and hematoma (n = 2 [6%]). The matched control group demonstrated similar complication rates without considerable differences, except for trismus (n = 16 [50%]), which was greater by a difference of 28.1% (95% CI, 5.6%-50.6%) in the control group.

Conclusions and Relevance

This cohort study examined surgical complications among patients with local regionally advanced OCSCC treated with neoadjuvant pembrolizumab and found that serious adverse events were similar to those in patients who underwent standard-of-care treatment. This suggests that there is no increased perioperative morbidity in the use of preoperative treatment with immunotherapy. Further prospective studies are needed to validate these findings for oral cavity cancer and other subsites of the head and neck.
The ubiquitin–proteasome system and autophagy mutually interact in neurotoxin‐induced dopaminergic cell death models of Parkinson's disease
Authors: Jang Hye Ji , Chung Kwang Chul
Published: August 2022

Precise control of the two major proteolysis systems [i.e. ubiquitin–proteasome system (UPS) and autophagy–lysosomal pathway (ALP)] is important for proper cell function. Here, we explored whether UPS and ALP affect each other in two neurotoxin‐based cell death models of Parkinson's disease. Monitoring UPS and ALP activity using their specific reporter plasmids revealed that treatment with the neurotoxin MPP+or the neurotoxin 6‐OHDA decreased proteasome activity in dopaminergic MN9D cells. Interestingly, ALP inhibition relieved or potentiated the decrease in proteasome activity induced by the two toxins. Moreover, suppression of proteasome activity promoted 6‐OHDA‐induced excessive autophagic flux, potentiating ALP dysregulation. In contrast, MPP+‐induced impairment of ALP was alleviated by proteasome inhibition. These findings suggest a dynamic interplay between UPS and ALP operating in MN9D cells under two distinct toxin‐mediated cell death pathways.
The effects of experience and uncertainty on hypothesis generation and testing in threat assessment
Authors: Leins Drew A. , Zimmerman Laura A. , Vowels Christopher L.
Published: August 2022

This study explored the decision‐making processes of soldiers as they evaluated scenarios containing information offering various levels of certainty. Soldiers with different levels of experience read scenarios that presented potential threats and then identified the priority threat, their confidence in this identification, and the cues they used to identify priority threats. Soldiers then searched for additional scenario‐relevant information and modified their reports if their assessments changed. Compared with inexperienced soldiers, experienced soldiers reported a greater number of priority threats and informative cues and were more likely to search additional topics that matched details in their initial assessments. High certainty scenarios yielded more identified threats, more cues, and higher confidence in initial reports. Soldiers' initial assessments rarely changed after additional information searches, but when they did, they were associated with low initial confidence.
Tuning the Mechanical and Electric Properties of Conjugated Polymer Semiconductors: Side‐Chain Design Based on Asymmetric Benzodithiophene Building Blocks
Authors: Liu Deyu , Lei Yusheng , Ji Xiaozhou , Wu Yilei , Lin Yangju , Wang Yunfei , Zhang Song , Zheng Yu , Chen Yuelang , Lai Jian‐Cheng , Zhong Donglai , Cheng Hao‐Wen , Chiong Jerika A. , Gu Xiaodan , Gam Sangah , Yun Youngjun , Tok Jeffrey B.‐H. , Bao Zhenan
Published: August 2022

Understanding molecular design rules for stretchable polymer semiconductors is important for enabling next generation stretchable electronic circuits. To simultaneously improve both electrical properties and mechanical stretchability, a design strategy is reported in introducing conjugated rigid fused‐rings with bulky side groups in semiconducting polymers. In this work, the understanding of this design concept is improved by systematically investigating the effect of different types of bulky side groups asymmetrically substituted on conjugated polymer semiconductor backbones. Specifically, four types of side groups are investigated, including naphthalene (NaPh), biphenyl (PhPh), thienylphenyl (ThPh), and alkylphenyl (C4Ph), asymmetrically substituted on benzodithiophene units, namely asy‐BDT. With the four types of side groups installed on BDT‐containing conjugated polymers in an asymmetrical fashion, it is observed that they reduced the polymer chain aggregation and film crystallinity, hence improving the film stretchability. Furthermore, the fully conjugated polymer backbone allows maintenance of good charge carrier mobilities. Specifically, polymer PDPP‐C4Ph (with C4Ph side groups) shows the highest mobility in the fully stretchable transistor and maintained its mobility even after being subjected to hundreds of stretching‐releasing cycles at 25% strain. Overall, the results provide anunderstanding of the use of asymmetrically substituted fused‐ring conjugated polymer structures to tune mechanical and charge transport properties.
Anomalous Thermal Transport Driven by Electron–Phonon Coupling in 2D Semiconductor h‐BP
Authors: Zhou Zizhen , Yang Xiaolong , Fu Huixia , Wang Rui , Lu Xu , Wang Guoyu , Zhou Xiaoyuan
Published: August 2022

The electron–phonon coupling (EPC) in semiconductors is typically much weaker than phonon–phonon scattering and its effect on lattice thermal conductivity κl has long been considered negligible. Herein, using first‐principle calculations, it is discovered that the EPC can be significant or even dominant over the intrinsic phonon–phonon scattering via doping in 2D semiconductor hexagonal boron phosphorus (h‐BP). Filling electron pocket till van Hove singularity gradually strengthens the EPC and consequently diminishes the room‐temperature κl by 25% and 80% for monolayer and bilayer h‐BP, respectively. Strikingly, at high doping levels, the EPC drives phonon transport in bilayer h‐BP to an anomalous regime where κl becomes nearly temperature (T) independent deviated from the intrinsic 1/T trend. This distinctive behavior is governed by the joint effects of horizontal mirror symmetry breaking, and weak phonon–phonon scattering stemming from the predominance of normal processes. Further considering electronic contributions, the abnormal T‐independent thermal conductivity is still reserved, thereby facilitating the experimental exploration of EPC effect on κl. This study unveils the exotic thermal transport phenomenon in one‐atom‐thick 2D semiconductors and offers a unique avenue to manipulate heat flow by externally controlling the EPC, which calls for future experimental verification.
Combined Corner‐Sharing and Edge‐Sharing Networks in Hybrid Nanocomposite with Unusual Lattice‐Oxygen Activation for Efficient Water Oxidation
Authors: Zhang Haijuan , Gao Yongxin , Xu Hengyue , Guan Daqin , Hu Zhiwei , Jing Chao , Sha Yuchen , Gu Yuxing , Huang Yu‐Cheng , Chang Yu‐Chung , Pao Chi‐Wen , Xu Xiaomin , Lee Jyh‐Fu , Chin Yi‐Ying , Lin Hong‐Ji , Chen Chien‐Te , Chen Yuhui , Guo Youmin , Ni Meng , Zhou Wei , Shao Zongping
Published: August 2022

Corner‐sharing and edge‐sharing networks are the two most important material genomes. Inspired by the efficient electron transport capacity of corner‐sharing structures and the low steric hindrance of edge‐sharing units, an attempt is made to exert both merits by combining these two networks. Here, a unique self‐assembled hybrid SrCo0.55Fe0.5O3‐δ nanorod composed of a corner‐sharing SrCo0.5Fe0.5O3‐δ phase and edge‐sharing Co3O4 structure is synthesized through a Co‐site enrichment method, which exhibits the low overpotentials of 310 and 290 mV at 10 mA cm–2 for oxygen‐evolving reaction in 0.1 m and 1.0 m KOH, respectively. This efficiency is attributed to the high Co valence with strong CoO covalence and the short distance between CoCo/Fe metal active sites in hybrid nanorods, realizing a synergistic benefit. Combined multiple operando/ex situ characterizations and computational studies show that the edge‐sharing units in hybrid nanorods can help facilitate the deprotonation step of lattice oxygen mechanism (LOM) while the corner‐sharing motifs can accelerate the electron transport during LOM processes, triggering an unusual lattice‐oxygen activation. This methodology of combining important material structural genomes can offer meaningful insights and guidance for various catalytic applications.
Transformable ECM Deprivation System Effectively Suppresses Renal Cell Carcinoma by Reversing Anoikis Resistance and Increasing Chemotherapy Sensitivity
Authors: Wang Lu , Li Cong , Wang Jiaqi , Yang Guang , Lv Yulin , Fu Bo , Jian Lingrui , Ma Jinpeng , Yu Jiaao , Yang Zongzheng , Wu Peng , Li Guangbin , Liu Xiao , Kang Zhijian , Wang Ziqi , Wang Lei , Wang Hao , Xu Wanhai
Published: August 2022

Extracellular matrix (ECM) is crucial in various biological functions during tumor progression, including induction of anoikis resistance and cell adhesion‐mediated drug resistance (CAM‐DR). Fibronectin (FN) is a vital ECM component with direct regulatory effects on ECM‐mediated anoikis resistance and CAM‐DR, making it an attractive and innovative therapeutic target for depriving ECM in tumor tissue. Herein, an ECM deprivation system (EDS) is developed based on FN targeting self‐assembly peptide for constructing nanofibers in the ECM of renal cell carcinoma (RCC), which contributes to: i) targeting and recognizing FN to form nanofibers for long‐term retention in ECM, ii) reversing anoikis resistance via arresting the FN signaling pathway, and iii) serving as a drug‐loading platform for sensitizing chemotherapy by ameliorating CAM‐DR. The results reveal that EDS significantly reverses anoikis resistance of RCC cells by inhibiting the phosphorylation of FAK, a positive regulator of the FN signaling pathway. Meanwhile, EDS serves as a chemotherapy‐sensitizer of cancer, exerting significant synergistic effects with doxorubicin (DOX). In vivo validation experiments show that EDS effectively suppresses metastasis and tumor growth with chemotherapy resistance. Collectively, the innovative EDS notably inhibits the tumor‐promoting effect of ECM and may provide a novel approach for suppressing ECM and enhancing chemo‐drug sensitivity.