bluuebunny/crossref_metadata_2025 huggingface dataset:
Natural Resistance to Intracellular Infections
Authors: Jabado Nada , Jankowski Andrzej , Dougaparsad Samuel , Picard Virginie , Grinstein Sergio , Gros Philippe
Published: July 2002

Mutations at the natural resistance–associated macrophage protein 1 (Nramp1) locus cause susceptibility to infection with antigenically unrelated intracellular pathogens. Nramp1 codes for an integral membrane protein expressed in the lysosomal compartment of macrophages, and is recruited to the membrane of phagosomes soon after the completion of phagocytosis. To define whether Nramp1 functions as a transporter at the phagosomal membrane, a divalent cation-sensitive fluorescent probe was designed and covalently attached to a porous particle. The resulting conjugate, zymosan–FF6, was ingested by macrophages and its fluorescence emission was recorded in situ after phagocytosis, using digital imaging. Quenching of the probe by Mn2+ was used to monitor the flux of divalent cations across the phagosomal membrane in peritoneal macrophages obtained from Nramp1-expressing (+/+) and Nramp1-deficient (−/−) macrophages. Phagosomes from Nramp1+/+ mice extrude Mn2+ faster than their Nramp−/− counterparts. The difference in the rate of transport is eliminated when acidification of the phagosomal lumen is dissipated, suggesting that divalent metal transport through Nramp1 is H+ dependent. These studies suggest that Nramp1 contributes to defense against infection by extrusion of divalent cations from the phagosomal space. Such cations are likely essential for microbial function and their removal from the phagosomal microenvironment impairs pathogenesis, resulting in enhanced bacteriostasis or bactericidal activity.
Development of Allergic Inflammation in a Murine Model of Asthma Is Dependent on the Costimulatory Receptor Ox40
Authors: Jember Amha Gebre-Hiwot , Zuberi Riaz , Liu Fu-Tong , Croft Michael
Published: July 2002

Asthma is thought to result from an abnormal expansion of CD4 T cells reactive with airborne allergens, and pathology is controlled by several cytokines of the T helper type 2 (Th2) family. The exact molecules which are involved in generating allergen-reactive T cells are not clear. Studies with blocking reagents or knockout animals have shown that the CD28/B7 interaction partially controls development of allergic asthma in mouse models, but may not be the sole molecule involved. In this report, we have investigated the role of the tumor necrosis factor receptor family member OX40 in allergic inflammation using OX40-deficient mice. OX40 has been shown to participate in regulating clonal expansion and memory development of CD4 T cells and may synergize with CD28. Our studies demonstrate that OX40−/− mice, primed with the model allergen ovalbumin and challenged through the airways with aerosolized antigen, are severely impaired in their ability to generate a Th2 response characterized by high levels of interleukin (IL)-5, IL-4, and immunoglobulin E. Moreover, OX40−/− mice exhibit diminished lung inflammation, including an 80–90% reduction in eosinophilia and mucus production, less goblet cell hyperplasia, and significantly attenuated airway hyperreactivity. These studies highlight the potential importance of OX40 in development of allergic asthma and suggest that targeting OX40 may prove useful therapeutically.
Cd47-Signal Regulatory Protein α (Sirpα) Regulates Fcγ and Complement Receptor–Mediated Phagocytosis
Authors: Oldenborg Per-Arne , Gresham Hattie D. , Lindberg Frederik P.
Published: July 2002

In autoimmune hemolytic anemia (AIHA), circulating red blood cells (RBCs) opsonized with autoantibody are recognized by macrophage Fcγ and complement receptors. This triggers phagocytosis and elimination of RBCs from the circulation by splenic macrophages. We recently found that CD47 on unopsonized RBCs binds macrophage signal regulatory protein α (SIRPα), generating a negative signal that prevents phagocytosis of the unopsonized RBCs. We show here that clearance and phagocytosis of opsonized RBCs is also regulated by CD47-SIRPα. The inhibition generated by CD47-SIRPα interaction is strongly attenuated but not absent in mice with only residual activity of the phosphatase Src homology 2 domain–containing protein tyrosine phosphatase (SHP)-1, suggesting that most SIRPα signaling in this system is mediated by SHP-1 phosphatase activity. The macrophage phagocytic response is controlled by an integration of the inhibitory SIRPα signal with prophagocytic signals such as from Fcγ and complement receptor activation. Thus, augmentation of inhibitory CD47-SIRPα signaling may prevent or attenuate RBC clearance in AIHA.
A Dap12-Mediated Pathway Regulates Expression of Cc Chemokine Receptor 7 and Maturation of Human Dendritic Cells
Authors: Bouchon Axel , Hernández-Munain Cristina , Cella Marina , Colonna Marco
Published: July 2002

Gene targeting of the adaptor molecule DAP12 in mice caused abnormal distribution and impaired antigen presentation capacity of dendritic cells (DCs). However, the DAP12-associated receptors expressed on DCs and their functions have not been identified yet. Here we show that the triggering receptor expressed on myeloid cells-2 (TREM-2) is a cell surface receptor on human monocyte-derived DCs, which is associated with DAP12. TREM-2/DAP12 promotes upregulation of CC chemokine receptor 7, partial DC maturation, and DC survival through activation of protein tyrosine kinases and extracellular signal–regulated kinase. In contrast to Toll-like receptor-mediated signaling, TREM2/DAP12 stimulation is independent of nuclear factor-κB and p38 stress-activated protein kinase. This novel DC activation pathway may regulate DC homeostasis and amplify DC responses to pathogens, explaining the phenotype observed in DAP12-deficient mice.
Salmonella Pathogenicity Island 2 Mediates Protection of Intracellular Salmonella from Reactive Nitrogen Intermediates
Authors: Chakravortty Dipshikha , Hansen-Wester Imke , Hensel Michael
Published: July 2002

Salmonella typhimurium causes an invasive disease in mice that has similarities to human typhoid. A type III protein secretion system encoded by Salmonella pathogenicity island 2 (SPI2) is essential for virulence in mice, as well as survival and multiplication within macrophages. Reactive nitrogen intermediates (RNI) synthesized by inducible nitric oxide synthase (iNOS) are involved in the control of intracellular pathogens, including S. typhimurium. We studied the effect of Salmonella infection on iNOS activity in macrophages. Immunofluorescence microscopy demonstrated efficient colocalization of iNOS with bacteria deficient in SPI2 but not wild-type Salmonella, and suggests that the SPI2 system interferes with the localization of iNOS and Salmonella. Furthermore, localization of nitrotyrosine residues in the proximity was observed for SPI2 mutant strains but not wild-type Salmonella, indicating that peroxynitrite, a potent antimicrobial compound, is excluded from Salmonella-containing vacuoles by action of SPI2. Altered colocalization of iNOS with intracellular Salmonella required the function of the SPI2-encoded type III secretion system, but not of an individual “Salmonella translocated effector.” Inhibition of iNOS increased intracellular proliferation of SPI2 mutant bacteria and, to a lesser extent, of wild-type Salmonella. The defect in systemic infection of a SPI2 mutant strain was partially restored in iNOS−/− mice. In addition to various strategies to detoxify RNI or repair damage due to RNI, avoidance of colocalization with RNI is important in adaptation of a pathogen to an intracellular life style.
A Dihydropyridine-sensitive Voltage-dependent Calcium Channel in the Sarcolemmal Membrane of Crustacean Muscle
Authors: Erxleben Christian , Rathmayer Werner
Published: July 2002

Single-channel currents through calcium channels in muscle of a marine crustacean, the isopod Idotea baltica, were investigated in cell-attached patches. Inward barium currents were strongly voltage-dependent, and the channels were closed at the cell's resting membrane potential. The open probability (Po) increased e-fold for an 8.2 mV (±2.4, n = 13) depolarization. Channel openings were mainly brief (<0.3 ms) and evenly distributed throughout 100-ms pulses. Averaged, quasimacroscopic currents showed fast activation and deactivation and did not inactivate during 100-ms test pulses. Similarly, channel activity persisted at steadily depolarized holding potentials. With 200 mM Ba2+ as charge carrier, the average slope conductance from the unitary currents between +30 and +80 mV, was 20 pS (±2.6, n = 12). The proportion of long openings, which were very infrequent under control conditions, was greatly increased by preincubation of the muscle fibers with the calcium channel agonist, the dihydropyridine Bay K8644 (10–100 μM). Properties of these currents resemble those through the L-type calcium channels of mammalian nerve, smooth muscle, and cardiac muscle cells.
Multi-Ion Mechanism for Ion Permeation and Block in the Cystic Fibrosis Transmembrane Conductance Regulator Chloride Channel
Authors: Linsdell Paul , Tabcharani Joseph A. , Hanrahan John W.
Published: July 2002

The mechanism of Cl− ion permeation through single cystic fibrosis transmembrane conductance regulator (CFTR) channels was studied using the channel-blocking ion gluconate. High concentrations of intracellular gluconate ions cause a rapid, voltage-dependent block of CFTR Cl− channels by binding to a site ∼40% of the way through the transmembrane electric field. The affinity of gluconate block was influenced by both intracellular and extracellular Cl− concentration. Increasing extracellular Cl− concentration reduced intracellular gluconate affinity, suggesting that a repulsive interaction occurs between Cl− and gluconate ions within the channel pore, an effect that would require the pore to be capable of holding more than one ion simultaneously. This effect of extracellular Cl− is not shared by extracellular gluconate ions, suggesting that gluconate is unable to enter the pore from the outside. Increasing the intracellular Cl− concentration also reduced the affinity of intracellular gluconate block, consistent with competition between intracellular Cl− and gluconate ions for a common binding site in the pore. Based on this evidence that CFTR is a multi-ion pore, we have analyzed Cl− permeation and gluconate block using discrete-state models with multiple occupancy. Both two- and three-site models were able to reproduce all of the experimental data with similar accuracy, including the dependence of blocker affinity on external Cl− (but not gluconate) ions and the dependence of channel conductance on Cl− concentration. The three-site model was also able to predict block by internal and external thiocyanate (SCN−) ions and anomalous mole fraction behavior seen in Cl−/SCN− mixtures.
A class of 3-dimensional manifolds with bounded first eigenvalue on 1-forms
Authors: Gentile Giovanni
Published: July 2002

Let

(
P
,
g
)

(P,g)

be the framebundle over an oriented,

C
∞

C^\infty

Riemannian surface

S
S

. Denote by

λ
−

1
,
1

(
P
,
g
)

\lambda -{1,1}(P,g)

the first nonzero eigenvalue of the Laplace operator acting on differential forms of degree 1. We prove that

λ

1
,
1

(
P
,
g
)
≤
c

\lambda _{1,1}(P,g)\le c

for all

(
P
,
g
)

(P,g)

with canonical metrics

g
g

of volume 1.
On generalized bisection of 𝑛-simplices
Authors: Horst Reiner
Published: July 2002

A generalized procedure of bisection of

n
n

–simplices is introduced, where the bisection point can be an (almost) arbitrary point at one of the longest edges. It is shown that nested sequences of simplices generated by successive generalized bisection converge to a singleton, and an exact bound of the convergence speed in terms of diameter reduction is given. For regular simplices, which mark the worst case, the edge lengths of each worst and best simplex generated by successive bisection are given up to depth

n
n

. For

n
=
2

n = 2

and

3
3

, the sequence of worst case diameters is provided until it is halved.
Development and validation of the predicted heat strain model
Authors: Malchaire J. , Piette A. , Kampmann B. , Mehnert P. , Gebhardt H. , Havenith G. , den Hartog E. , Holmer I. , Parsons K. , Alfano G. , Griefahn B.
Published: July 2002

Eight laboratories participated in a concerted research project on the assessment of hot working conditions. The objectives were, among others, to co-ordinate the work of the main European research teams in the field of thermal factors and to improve the methods available to assess the risks of heat disorders at the workplace, and in particular the “Required Sweat Rate” model as presented in International Standard ISO 7933 Standard (1989). The scientific bases of this standard were thoroughly reviewed and a revised model, called “Predicted Heat Strain” (PHS), was developed. This model was then used to predict the minute by minute sweat rates and rectal temperatures during 909 laboratory and field experiments collected from the partners. The Pearson correlation coefficients between observed and predicted values were equal to 0.76 and 0.66 for laboratory experiments and 0.74 and 0.59 for field experiments, respectively, for the sweat rates and the rectal temperatures. The change in sweat rate with time was predicted more accurately by the PHS model than by the required sweat rate model. This suggests that the PHS model would provide an improved basis upon which to determine allowable exposure times from the predicted heat strain in terms of dehydration and increased core temperature.
Detecting hypermutations in viral sequences with an emphasis on
G → A hypermutation
Authors: Rose Patrick P. , Korber Bette T.
Published: July 2002

Summary: This program compares sequence sets to a reference sequence, tallies G → A hypermutations, and presents the results in various tables and graphs, which include dinucleotide context, summaries of all observed nucleotide changes, and stop codons introduced by hypermutation.

Availability: www.hiv.lanl.gov/HYPERMUT/hypermut.html

Contact: pxr@t10.lanl.govor btk@t10.lanl.gov
Attention, self–regulation and consciousness
Authors:   The American Association for Research into Nervous and Mental Diseases, Posner M. I. , Rothbart M. K.
Published: July 2002

Consciousness has many aspects. These include awareness of the world, feelings of control over one's behaviour and mental state (volition), and the notion of a continuing self. Focal (executive) attention is used to control details of our awareness and is thus closely related to volition. Experiments suggest an integrated network of neural areas involved in executive attention. This network is associated with our voluntary ability to select among competing items, to correct error and to regulate our emotions. Recent neuroimaging studies suggest that these various functions involve separate areas of the anterior cingulate.

We have adopted a strategy of using marker tasks, shown to activate the brain area by imaging studies, as a means of tracing the development of attentional networks. Executive attention appears to develop first to regulate distress during the first year of life. During later childhood the ability to regulate conflict among competing stimuli builds upon the earlier cingulate anatomy to provide a means of cognitive control. During childhood the activation of cingulate structures relates both to the child's success on laboratory tasks involving conflict and to parental reports of self–regulation and emotional control. These studies indicate a start in understanding the anatomy, circuitry and development of executive attention networks that serve to regulate both cognition and emotion.
The future of organ transplantation: from the laboratory to the clinic
Authors: Calne R. Y.
Published: July 2002

This is a short review of tolerance from the point of view of the clinician. Various examples of tolerance occurring in patients and animal models that relate to the clinical experience are described. It is suggested that there may be different mechanisms by which tolerance is achieved, but from the patient's point of view operational tolerance is the goal, whereby, after a short induction procedure, the patient will maintain good function in the grafted organ indefinitely without maintenance immunosuppression. It is pointed out that such a goal may be difficult to achieve with any given protocol due to the enormous variation between donors and recipients of organ grafts of tissue matching, innate immune reactivity and susceptibility to disturbance of a tolerant state by infections or allergic reactions. Thus the case is made for prope or almost tolerance in which graft acceptance is maintained by a low, non–toxic dosage of maintenance immunosuppression that may not be required indefinitely.
“Weather” records: Musings on cold days after a long hot Indian summer
Authors: Schmittmann B. , Zia R. K. P.
Published: July 2002

We present a simple introduction to the statistics of extreme values. Motivated by a string of record high temperatures in December 1998, we consider the distribution, averages, and lifetimes for a simplified model of such “records.” Our data are sequences of independent random numbers all of which are generated from the same probability distribution. A remarkable universality emerges: A number of results, including the lifetime histogram, are universal, that is, independent of the underlying distribution.
Invariant operators for quadratic Hamiltonians
Authors: Andrews Mark
Published: July 2002

The motion of wave packets can be easily determined for any Hamiltonian that is quadratic in position and momentum, even if the coefficients of the terms in the Hamiltonian vary with time. The method is based on the existence of an invariant operator, linear in position and momentum, the coefficients of these operators being solutions of the corresponding classical system. This immediately yields a set of very simple wave packets whose evolution is easily determined, and whose magnitude has the same form as the energy eigenfunctions of the harmonic oscillator (i.e., Gaussian or Hermite–Gaussian). This set provides a complete basis for finding the evolution of any state and the exact propagator is readily determined. For the harmonic oscillator, this set includes coherent states, squeezed states, displaced number states, and squeezed number states as special cases. The following important properties hold for every quadratic Hamiltonian, no matter what time dependence is present in the Hamiltonian: (1) The motion of the centroid of any wave packet separates from that of any moments relative to the centroid. (2) Every detail of the evolution of the quantum system can be calculated from the solutions of the corresponding classical system. (3) Wave functions of Gaussian (or Hermite–Gaussian) form will retain that form as they evolve.
A human nonlinear cochlear filterbank
Authors: Lopez-Poveda Enrique A. , Meddis Ray
Published: July 2002

Some published cochlear filterbanks are nonlinear but are fitted to animal basilar membrane (BM) responses. Others, like the gammatone, are based on human psychophysical data, but are linear. In this article, a human nonlinear filterbank is constructed by adapting a computational model of animal BM physiology to simulate human BM nonlinearity as measured by psychophysical pulsation-threshold experiments. The approach is based on a dual-resonance nonlinear type of filter whose basic structure was modeled using animal observations. In modeling the pulsation threshold data, the main assumption is that pulsation threshold occurs when the signal and the masker produce comparable excitation, that is the same filter output, at the place of the BM best tuned to the signal frequency. The filter is fitted at a discrete number of best frequencies (BFs) for which psychophysical data are available for a single listener and for an average response of six listeners. The filterbank is then created by linear regression of the resulting parameters to intermediate BFs. The strengths and limitations of the resulting filterbank are discussed. Its suitability for simulating hearing-impaired cochlear responses is also discussed.
Sound transmission through a double leaf partition with edge flanking
Authors: Craik R. J. M. , Nightingale T. R. T. , Steel J. A.
Published: July 2002

Lightweight double leaf partitions are widely used and with proper design give good sound isolation. However, when these walls are used as party walls between dwellings, then precautions are necessary to prevent the transmission of fire and smoke. This is usually carried out by placing a firestop in the cavity. This firestop introduces flanking transmission paths reducing the airborne transmission loss of the wall. A simple model is developed which can predict vibration transmission across this type of structural connection. The structural vibration transmission loss can then be used with a more general statistical energy analysis model to give the sound transmission through the entire system. Predicted airborne transmission loss results for a variety of different materials are compared with measured results and good agreement is obtained.
Basilar-membrane responses to tones at the base of the chinchilla cochlea
Authors: Ruggero Mario A. , Rich Nola C. , Recio Alberto , Narayan S. Shyamla , Robles Luis
Published: July 2002

Basilar-membrane responses to single tones were measured, using laser velocimetry, at a site of the chinchilla cochlea located 3.5 mm from its basal end. Responses to low-level (<10–20 dB SPL) characteristic-frequency (CF) tones (9–10 kHz) grow linearly with stimulus intensity and exhibit gains of 66–76 dB relative to stapes motion. At higher levels, CF responses grow monotonically at compressive rates, with input–output slopes as low as 0.2 dB/dB in the intensity range 40–80 dB. Compressive growth, which is significantly correlated with response sensitivity, is evident even at stimulus levels higher than 100 dB. Responses become rapidly linear as stimulus frequency departs from CF. As a result, at stimulus levels >80 dB the largest responses are elicited by tones with frequency about 0.4–0.5 octave below CF. For stimulus frequencies well above CF, responses stop decreasing with increasing frequency: A plateau is reached. The compressive growth of responses to tones with frequency near CF is accompanied by intensity-dependent phase shifts. Death abolishes all nonlinearities, reduces sensitivity at CF by as much as 60–81 dB, and causes a relative phase lead at CF.
Factors affecting children’s speech communication in classrooms
Authors: Soli Sigfrid D. , Sullivan Jean A.
Published: July 2002

A child’s ability to hear and communicate with speech in the classroom is influenced by several factors, including talker characteristics (level, clarity, dialect), the acoustical environment (noise level, reverberance), and listener characteristics (hearing status, cognitive development, language level, exposure to English). This presentation will review and assess the relative contribution of each factor to the communication requirements of the classroom. An emphasis will be placed on the large individual differences in listener characteristics that are likely to exist in contemporary classrooms, and their impact on the requirements of the acoustic environment for effective speech communication. Recent findings from this laboratory and from other researchers that document the range of speech communication abilities in both difficult and easy listening conditions among school-age children will be reviewed. Finally, an initial proposal for acceptable levels of background noise and reverberance in classrooms based on these findings will be offered. The rationale for this proposal is that noise and reverberance levels must be low enough to allow children with a wide range of listener characteristics to communicate with speech easily and effectively in the classroom. [See NOISE-CON Proceedings for full paper.]
Performance of noise indices in air-conditioned landscaped office buildings
Authors: Tang S. K.
Published: July 2002

Noise measurements and a questionnaire survey were carried out in air-conditioned landscaped offices in the present study in an attempt to find out what existing noise index gives the best correlation with the auditory sensation feeling of office workers. Results from statistical analyses show that the Equivalent Sound Pressure Level is the best among the 14 commonly used noise indices for this purpose. It is also found that the less commonly used Zwicker’s loudness level performs better than the commonly adopted Noise Criterion curves and Noise Rating curves in predicting auditory sensation of office workers in air-conditioned landscaped offices. The performance of the 14 noise indices in predicting auditory comfort are compared.
The perceptual prominence of fundamental frequency peaks
Authors: Gussenhoven C. , Repp B. H. , Rietveld A. , Rump H. H. , Terken J.
Published: July 2002

Five perception experiments were conducted that investigated how the perceived prominence of F0 maxima in accented syllables in Dutch is affected by the variation of F0 minima that is supposed to relate to variation in global pitch range. The purpose of the first two experiments was to test the predictions of a model in which the reference line is directly given by an interpolation between observable F0 minima. The results showed that the model was inadequate, and confirmed earlier research suggesting that the reference line is calculated in a less direct way. The next three experiments investigated the role of the F0 of the unaccented portions of speech at the beginning (“onset”) and at the end (“offset”) of the contour, and show that only the (low) onset is used to calibrate the reference line. The results also suggest that longer onsets affect the abstract reference more than do shorter onsets.
Context-independent dynamic information for the perception of coarticulated vowels
Authors: Jenkins James J. , Strange Winifred , Trent Sonja A.
Published: July 2002

Most investigators agree that the acoustic information for American English vowels includes dynamic (time-varying) parameters as well as static “target” information contained in a single cross section of the syllable. Using the silent-center (SC) paradigm, the present experiment examined the case in which the initial and final portions of stop consonant–vowel–stop consonant (CVC) syllables containing the same vowel but different consonants were recombined into mixed-consonant SC syllables and presented to listeners for vowel identification. Ten vowels were spoken in six different syllables, /bVb, bVd, bVt, dVb, dVd, dVt/, embedded in a carrier sentence. Initial and final transitional portions of these syllables were cross-matched in: (1) silent-center syllables with original syllable durations (silences) preserved (mixed-consonant SC condition) and (2) mixed-consonant SC syllables with syllable duration equated across the ten vowels (fixed duration mixed-consonant SC condition). Vowel-identification accuracy in these two mixed consonant SC conditions was compared with performance on the original SC and fixed duration SC stimuli, and in initial and final control conditions in which initial and final transitional portions were each presented alone. Vowels were identified highly accurately in both mixed-consonant SC and original syllable SC conditions (only 7%–8% overall errors). Neutralizing duration information led to small, but significant, increases in identification errors in both mixed-consonant and original fixed-duration SC conditions (14%–15% errors), but performance was still much more accurate than for initial and finals control conditions (35% and 52% errors, respectively). Acoustical analysis confirmed that direction and extent of formant change from initial to final portions of mixed-consonant stimuli differed from that of original syllables, arguing against a target+offglide explanation of the perceptual results. Results do support the hypothesis that temporal trajectories specifying “style of movement” provide information for the differentiation of American English tense and lax vowels, and that this information is invariant over the place of articulation and voicing of the surrounding stop consonants.
Effectiveness of spatial cues, prosody, and talker characteristics in selective attention
Authors: Darwin C. J. , Hukin R. W.
Published: July 2002

The three experiments reported here compare the effectiveness of natural prosodic and vocal-tract size cues at overcoming spatial cues in selective attention. Listeners heard two simultaneous sentences and decided which of two simultaneous target words came from the attended sentence. Experiment 1 used sentences that had natural differences in pitch and in level caused by a change in the location of the main sentence stress. The sentences’ pitch contours were moved apart or together in order to separate out effects due to pitch and those due to other prosodic factors such as intensity. Both pitch and the other prosodic factors had an influence on which target word was reported, but the effects were not strong enough to override the spatial difference produced by an interaural time difference of ±91 μs. In experiment 2, a large (±15%) difference in apparent vocal-tract size between the speakers of the two sentences had an additional and strong effect, which, in conjunction with the original prosodic differences overrode an interaural time difference of ±181 μs. Experiment 3 showed that vocal-tract size differences of ±4% or less had no detectable effect. Overall, the results show that prosodic and vocal-tract size cues can override spatial cues in determining which target word belongs in an attended sentence.
Radiated noise characteristics of a modern cargo ship
Authors: Arveson Paul T. , Vendittis David J.
Published: July 2002

Extensive measurements were made of the radiated noise of M/V OVERSEAS HARRIETTE, a bulk cargo ship (length 173 m, displacement 25 515 tons) powered by a direct-drive low-speed diesel engine—a design representative of many modern merchant ships. The radiated noise data show high-level tonal frequencies from the ship’s service diesel generator, main engine firing rate, and blade rate harmonics due to propeller cavitation. Radiated noise directionality measurements indicate that the radiation is generally dipole in form at lower frequencies, as expected. There are some departures from this pattern that may indicate hull interactions. Blade rate source level (174 dB re 1 μPa/m at 9 Hz, 16 knots) agrees reasonably well with a model of fundamental blade rate radiation previously reported by Gray and Greeley, but agreement for blade rate harmonics is not as good. Noise from merchant ships elevates the natural ambient by 20–30 dB in many areas; the effects of this noise on the biological environment have not been widely investigated.
An Experimental Study of a Nonlinear Material with Memory
Authors: Neis V. V. , Sackman J. L.
Published: July 2002

The applicability of a functional polynomial of third degree for the constitutive equation of a nonlinear viscoelastic polymer has been investigated. A method for the determination of the kernel functions appearing in the one-dimensional creep formulation has been discussed. Creep measurements of tension and compression in low density polyethylene under single step, two step, and three step loading histories are described. The analysis of this data has provided a basis for determination of the creep kernel functions. For the loading range used in the test, the Volterra-Fréchet multiple integral expansion of the constitutive functional of low density polyethylene has been found to be adequately represented by the three-term integral representation. A number of cases of general load histories was investigated. A close comparison between the experimental response to these loading histories and the response predicted by the three-term integral representation was obtained.
Acute Pulmonary Embolism
Authors: Freund Yonathan , Cohen-Aubart Fleur , Bloom Ben
Published: October 2022

Importance

Pulmonary embolism (PE) is characterized by occlusion of blood flow in a pulmonary artery, typically due to a thrombus that travels from a vein in a lower limb. The incidence of PE is approximately 60 to 120 per 100 000 people per year. Approximately 60 000 to 100 000 patients die from PE each year in the US.

Observations

PE should be considered in patients presenting with acute chest pain, shortness of breath, or syncope. The diagnosis is determined by chest imaging. In patients with a systolic blood pressure of at least 90 mm Hg, the following 3 steps can be used to evaluate a patient with possible PE: assessment of the clinical probability of PE, D-dimer testing if indicated, and chest imaging if indicated. The clinical probability of PE can be assessed using a structured score or using clinical gestalt. In patients with a probability of PE that is less than 15%, the presence of 8 clinical characteristics (age <50 years, heart rate <100/min, an oxygen saturation level of > 94%, no recent surgery or trauma, no prior venous thromboembolism event, no hemoptysis, no unilateral leg swelling, and no estrogen use) identifies patients at very low risk of PE in whom no further testing is needed. In patients with low or intermediate clinical probability, a D-dimer level of less than 500 ng/mL is associated with a posttest probability of PE less than 1.85%. In these patients, PE can be excluded without chest imaging. A further refinement of D-dimer threshold is possible in patients aged 50 years and older, and in patients with a low likelihood of PE. Patients with a high probability of PE (ie, >40% probability) should undergo chest imaging, and D-dimer testing is not necessary. In patients with PE and a systolic blood pressure of 90 mm Hg or higher, compared with heparin combined with a vitamin K antagonist such as warfarin followed by warfarin alone, direct oral anticoagulants such as apixaban, edoxaban, rivaroxaban, or dabigatran, are noninferior for treating PE and have a 0.6% lower rate of bleeding. In patients with PE and systolic blood pressure lower than 90 mm Hg, systemic thrombolysis is recommended and is associated with an 1.6% absolute reduction of mortality (from 3.9% to 2.3%).

Conclusions and Relevance

In the US, PE affects approximately 370 000 patients per year and may cause approximately 60 000 to 100 000 deaths per year. First-line therapy consists of direct oral anticoagulants such as apixaban, edoxaban, rivaroxaban, or dabigatran, with thrombolysis reserved for patients with systolic blood pressure lower than 90 mm Hg.
What Is Pulmonary Embolism?
Authors: Walter Kristin
Published: October 2022

This JAMA Patient Page describes pulmonary embolism signs and symptoms, risk factors, diagnosis, and treatment options.
Association of Hurried Communication and Low Patient Self‐Efficacy With Persistent Nonadherence to Lupus Medications
Authors: Barr Ann Cameron , Clowse Megan , Maheswaranathan Mithu , Eder Lena , Eudy Amanda M. , Criscione‐Schreiber Lisa G. , Rogers Jennifer L. , Sadun Rebecca E. , Doss Jayanth , Sun Kai
Published: October 2022

Objective

Medication nonadherence is common among patients with systemic lupus erythematosus (SLE), and adherence often fluctuates with time. Underrepresented racial minorities have disproportionately lower rates of medication adherence and more severe SLE manifestations. We aimed to identify modifiable factors associated with persistent medication nonadherence.

Methods

Patients taking ≥1 SLE medication were enrolled. Adherence data were obtained at baseline and at follow‐up roughly 1 year later using both self‐reported adherence and pharmacy refill data. Covariates included patient–provider interaction, patient self‐efficacy, and clinical factors. We compared characteristics of patients in 3 groups using the Kruskal‐Wallis H test: persistent nonadherence (low adherence by self‐report and refill rates at both time points); persistent adherence (high adherence by self‐report and refill rates at both time points); and inconsistent adherence (the remainder).

Results

Among 77 patients (median age 44 years, 53% Black, 96% female), 48% had persistent nonadherence. Compared with other adherence groups, patients with persistent nonadherence were younger and more likely to be Black, have lower income, take ≥2 SLE medications, have higher SLE‐related damage at baseline, and have higher physician global assessment of disease activity at follow‐up. Persistently nonadherent patients also rated more hurried communication with providers (particularly fast speech and difficult word choice) and had lower self‐efficacy in managing medications.

Conclusion

Potential avenues to improve medication adherence include optimizing patient–provider communication, specifically avoiding difficult vocabulary and fast speech, and enhancing patient self‐efficacy, particularly among younger Black patients with lower income who are at higher risk for nonadherence.
Evaluation of Financial and Nonfinancial Conflicts of Interest and Quality of Evidence Underlying Psoriatic Arthritis Clinical Practice Guidelines: Analysis of Personal Payments From Pharmaceutical Companies and Authors’ Self‐Citation Rate in Japan and the United States
Authors: Mamada Hanano , Murayama Anju , Kamamoto Sae , Kaneda Yudai , Yoshida Makoto , Sugiura Sota , Yamashita Erika , Kusumi Eiji , Saito Hiroaki , Sawano Toyoaki , Tanimoto Tetsuya , Vassar Matt , Ozieranski Piotr , Ozaki Akihiko
Published: October 2022

Objective

To assess financial conflicts of interest (COI) and nonfinancial COI among psoriatic arthritis (PsA) clinical practice guideline (CPG) authors in Japan and the US, and to evaluate the quality of evidence and strength of recommendations of PsA CPGs.

Methods

We performed a retrospective analysis using payment data from major Japanese pharmaceutical companies and the US Open Payments Database from 2016 to 2018. All authors of PsA CPGs issued by the Japanese Dermatological Association (JDA) and American College of Rheumatology (ACR) were included.

Results

Of 23 CPG authors in Japan, 21 (91.3%) received at least 1 payment, with a combined total of $3,335,413 between 2016 and 2018. Regarding 25 US authors, 21 (84.0%) received at least 1 payment, with a combined total of $4,081,629 during the same period. The 3‐year combined mean ± SD payment per author was $145,018 ± $114,302 in Japan and $162,825 ± $259,670 in the US. A total of 18 authors (78.3%) of the JDA PsA CPG and 12 authors (48.0%) of the ACR PsA CPG had undisclosed financial COI worth $474,663 and $218,501, respectively. The percentage of citations with at least 1 CPG author relative to total citations was 3.4% in Japan and 33.6% in the US. In sum, 71.4% and 88.8% of recommendations for PsA in the JDA and ACR were supported by low or very low quality of evidence.

Conclusion

More rigorous cross‐checking of information disclosed by pharmaceutical companies and self‐reported by physicians and more stringent and transparent COI policies are necessary.
Organic Ligand‐Free ZnO Quantum Dots for Efficient and Stable Perovskite Solar Cells
Authors: Chavan Rohit D. , Wolska‐Pietkiewicz Małgorzata , Prochowicz Daniel , Jędrzejewska Maria , Tavakoli Mohammad Mahdi , Yadav Pankaj , Hong Chang Kook , Lewiński Janusz
Published: October 2022

Zinc oxide (ZnO) is a promising electron‐transport layer (ETL) in thin‐film photovoltaics. However, the poor chemical compatibility between commonly used sol–gel‐derived ZnO nanostructures and organo–metal halide perovskites makes it highly challenging to obtain efficient and stable perovskite solar cells (PSCs). Here, a novel approach is reported for low‐temperature processed pure ZnO ETLs for planar heterojunction PSCs based on ZnO quantum dots (QDs) stabilized by dimethyl sulfoxide (DMSO) as easily removable solvent molecules. With no need for the ETL doping or surface modification, the champion PSC comprising the mixed‐cation and mixed‐halide Cs5(MA0.17FA0.83)95Pb(I0.83Br0.17)3 absorber layer reaches a maximum power conversion efficiency of 20.05%, which is significantly higher than that obtained for a reference device based on a standard sol–gel‐derived ZnO nanostructured layer (17.78%). Thus, along with the observed better operational stability in ambient conditions and elevated temperature, the champion device achieves the state‐of‐the‐art performance among reported non‐passivated pure ZnO ETL‐based PSCs. The improved photovoltaic performance is attributed to both a higher uniformity of the surface morphology and a lower defects density of films based on the organometallic‐derived QDs that are likely to ensure the enhanced stability of the ZnO/perovskite interface.
Binder‐Free Wood Converted Carbon for Enhanced Water Desalination Performance
Authors: He Rui , Neupane Manish , Zia Akhter , Huang Xiaozhou , Bowers Crystal , Wang Min , Lu Jun , Yang Yingchao , Dong Pei
Published: October 2022

The design and synthesis of high‐performance and economical carbon electrodes play a critical role in developing energy‐efficient water desalination technologies. As a sustainable approach, low‐cost and abundant biomass materials are promising candidates to prepare porous carbon for capacitive deionization. In this study, binder‐free porous carbon sheets are successfully prepared using natural balsa, pine, and basswood by thermal carbonization and treated by chemical activation. The carbon electrode materials converted from balsa and pine exhibit a comparable salt adsorption performance by capacitive deionization due to the extensive surface area, substantial electrical property, and superior hydrophilic performance. The following activation treatment of the balsa‐converted carbon further enhances the surface and electrical properties and benefits the desalination performance. The salt adsorption capacity of the activated balsa electrode exhibits 12.45 mg g−1. Additionally, 19.52 mg g−1 Pb2+ and 20.06 mg g−1 Cr3+ heavy metal adsorption capacity is also observed with the activated balsa electrode in 100 mg L−1 PbCl2 and 50 mg L−1 CrCl3, respectively. To the best of authors’ knowledge, this is the highest NaCl adsorption capacity performance reported thus far by using pure wood converted carbon as the electrode, and these promising results indicate that activated balsa is an extraordinary material for water desalination.
High‐Energy‐Density Supercapacitors Based on High‐Areal‐Specific‐Capacity Ti3C2Tx and a Redox‐Active Organic‐Molecule Hybrid Electrode
Authors: Zhang Haoxiang , Wang Le , Xing Xinxin , Zhao Shuai , Wang Kai , Liu Shengzhong (Frank)
Published: October 2022

Photorechargeable supercapacitors are perfect energy storage devices, particularly for solar cells that output electricity only during sunshine hours. The lower energy density of supercapacitors is due to fewer redox‐active sites, poor electrolyte accessibility at the electrodes, and charge loss during charge transfer from solar cells to the supercapacitor. Here, an electrolyte‐accessible organic–inorganic hybrid electrode with synergistic pseudocapacitance of Ti3C2Tx and high theoretical specific capacity CO active centers to enhance the energy density of the supercapacitor is proposed. Density functional theory (DFT) calculations show that the covalent cross‐linking of organic molecules changes the charge density redistribution of Ti3C2Tx, enhances ion absorption and storage, and increases the energy density of the supercapacitors. Based on these DFT calculation results, hybrid electrodes are successfully prepared using p‐phenylene diisocyanate to covalently cross‐link pseudocapacitors Ti3C2Tx with anthraquinone such as 1‐hydroxyanthraquinone (HA) or 1‐amino‐4‐bromoanthraquinone‐2‐sodium sulfonate (ABS). The Ti3C2Tx‐HA hybrid electrodes exhibit high areal specific capacity (2532.5 mF cm−2), excellent ion absorption storage capability, and long‐term stability. The asymmetric supercapacitor yields a decent area specific capacity (1686.72 mF cm−2 at 0.25 mA cm−2) and energy density (599.72 mWh cm−2 at a power density of 200 mW cm−2). These high‐energy‐density supercapacitors are coupled with perovskite solar cells to prepare photorechargeable supercapacitors with fast energy storage.
Machine‐Learning Spectral Indicators of Topology
Authors: Andrejevic Nina , Andrejevic Jovana , Bernevig B. Andrei , Regnault Nicolas , Han Fei , Fabbris Gilberto , Nguyen Thanh , Drucker Nathan C. , Rycroft Chris H. , Li Mingda
Published: October 2022

Topological materials discovery has emerged as an important frontier in condensed matter physics. While theoretical classification frameworks have been used to identify thousands of candidate topological materials, experimental determination of materials’ topology often poses significant technical challenges. X‐ray absorption spectroscopy (XAS) is a widely used materials characterization technique sensitive to atoms’ local symmetry and chemical bonding, which are intimately linked to band topology by the theory of topological quantum chemistry (TQC). Moreover, as a local structural probe, XAS is known to have high quantitative agreement between experiment and calculation, suggesting that insights from computational spectra can effectively inform experiments. In this work, computed X‐ray absorption near‐edge structure (XANES) spectra of more than 10 000 inorganic materials to train a neural network (NN) classifier that predicts topological class directly from XANES signatures, achieving F1 scores of 89% and 93% for topological and trivial classes, respectively is leveraged. Given the simplicity of the XAS setup and its compatibility with multimodal sample environments, the proposed machine‐learning‐augmented XAS topological indicator has the potential to discover broader categories of topological materials, such as non‐cleavable compounds and amorphous materials, and may further inform field‐driven phenomena in situ, such as magnetic field‐driven topological phase transitions.
Spatial Nonreciprocal Transmission and Optical Bistability Based on Millimeter‐Scale Suspended Metasurface
Authors: Sang You , Xu Jipeng , Liu Ken , Chen Wei , Xiao Yong , Zhu Zhihong , Liu Ning , Zhang Jianfa
Published: October 2022

When light interacts with microscopic objects at the micro‐ and nano‐scale, the momentum exchange between photons and objects can be very significant. While the optical radiation pressure at the same level is usually too weak to change the mechanical state of macro‐scale objects at millimeter scale or beyond. Suspended metasurfaces with excellent mechanical and optical properties are ideal candidates for light‐matter interactions. Here, without sound insulation conditions, the spatial optical nonreciprocity based on an optomechanical system with a 2 mm × 2 mm × 110 nm Si3N4 suspended metasurface at the telecom wavelength is demonstrated, with peak wavelength shift up to 1.1 pm, which is about 4.0 times of the full width at half maximum, together with optical bistability at only about 10 W cm−2 input intensities, which is more than 4 orders of magnitude lower than traditional nonlinear optical mechanism. This work may pave new avenues for spatially nonreciprocal devices and bistable devices, and benefit the applications such as precision sensing, cavity quantum optomechanics, and all‐optical switching.
Sustainable Thermoelectric Materials Predicted by Machine Learning
Authors: Chernyavsky Dmitry , van den Brink Jeroen , Park Gyu‐Hyeon , Nielsch Kornelius , Thomas Andy
Published: October 2022

Using datasets from several sources, a list of more than 450 materials is generated and related them with their thermoelectric properties. This is obtained by generating a set of features using only the molecular formula. Subsequently, a machine learning algorithm classifies the materials in specific, binary classes, for example, possessing high or low Seebeck coefficients or electrical conductivity. After adjusting the threshold values and grouping the materials into clusters, the thermoelectric performance of more than 25k materials is predicted. Finally, the results are filtered to obtain only the sustainable materials, that is, neither toxic nor critical, (ideally) inexpensive, and isotropic with regard to their transport properties to simplify the preparation procedure.