bluuebunny/crossref_metadata_2025 huggingface dataset:
Centers for Disease Control and Prevention non-occupational noise campaign
Authors: Eichwald John
Published: June 2021

In February 2017, an intra-agency workgroup within the Centers for Disease Control and Prevention (CDC) National Center for Environmental Health (NCEH) launched a hearing loss campaign to increase awareness that excessive exposure to loud sounds outside of the working environment can lead to permanent noise-induced hearing loss (NIHL). The NCEH workgroup initiated research efforts and participated in activities to promote the prevention of NIHL from non-occupational noise exposures. This included the development of an online toolkit with infographics, videos, and other sharable media, several available in English and Spanish. Publication of CDC NIHL research has included peer-reviewed journals, partner articles and Morbidity and Mortality Weekly Report (MMWR) manuscripts. The CDC NIHL workgroup engages with various organizations and continues to analyze national data to prioritize public health needs in this area. CDC continues to develop communication materials, social media content, videos, and factsheets to support partners and other stakeholders. By providing evidence and education/health communication; through its partners CDC collaborates with other national efforts to increase awareness and behavioral change to prevent NIHL at home and in the community.
National data on noise exposure, hearing trouble, and protective behaviors in the United States
Authors: Themann Christa L.
Published: June 2021

Although exposure to hazardous noise is generally considered to be the major cause of preventable hearing loss among adults, the U.S. does not have a measurement-based surveillance system to track noise exposure. However, several national health survey systems collect self-reported noise exposure information as well as related data including self-rated and/or audiometrically-measured hearing trouble and self-reported hearing protection use. This presentation will provide estimates of exposure to loud noise from various sources among a nationally representative sample of U.S. adults based on data from the National Health Interview Survey and the National Health and Nutrition Examination Survey. Prevalence of self-reported and measured hearing impairment as well as tinnitus will also be reported and examined in relation to the various types and combinations of exposure. In addition, the frequency of hearing protector use and audiometric monitoring among individuals exposed to various types of noise will be examined to evaluate their possible influence on the prevalence of auditory symptoms and identify groups in particular need of targeted interventions. This presentation will provide a snapshot of the noise exposure problem in the U.S., illustrate its effects on hearing ability among U.S. adults, and highlight the most significant hearing-related public health needs.
Progress on the National Occupational Research Agenda for hearing loss prevention
Authors: Murphy William J. , Wells Lauraine L. , Matetic Rudy J. , Masterson Elizabeth , Azman Amanda S.
Published: June 2021

In 2019, the National Institute for Occupational Safety and Health, Hearing Loss Prevention (HLP) Cross-sector Council published the National Occupational Research Agenda (NORA) for Hearing Loss Prevention. The agenda consisted of five objectives: (1) provide input for policies and guidelines that will inform best practices for hearing loss prevention efforts; (2) develop effective, evidence-based education designed to improve hearing conservation program outcomes for exposed workers and management; (3) develop, commercialize, and widely implement noise control solutions on jobsites in key industries; (4) develop audiological tests for hearing loss prevention; and (5) improve occupational hearing loss surveillance. In this paper, these objectives will be reviewed with regards to progress that has been accomplished. The NORA HLP Cross-sector Council has focused on expanding awareness for noise awareness and developing guidance for hearing protector fit testing. While these efforts are more directed to preventing occupational noise-induced hearing loss, the principles carry over to preventing hearing loss outside of the occupational setting.
Radiation force fields formed by a standing surface acoustic wave in a viscous liquid layer lying on an elastic half-space
Authors: Zharkov Denis A. , Gusev Vladimir A.
Published: June 2021

The field of a surface acoustic wave in the system “viscous fluid layer—elastic substrate” is calculated taking into account the shear components in the fluid. On the basis of the dispersion equation, the velocity and attenuation of the surface wave are calculated. It is shown that for low-viscosity liquids the change in velocity is insignificant, but the shear components make the main contribution to the attenuation of the wave. The radiation pressure corresponding to a standing surface wave in a viscous fluid and acting on an element of its volume due to the nonlinearity of the equation of motion is calculated. It is shown that taking viscosity into account changes the spatial distribution of radiation pressure. In the presence of suspended particles in the liquid form, the attenuation of the wave causes an additional tendency to collect these particles in the center of the system. The shear components have significant radiation pressure gradients near the interface. They play a decisive role in the formation of ordered ensembles of particles at the last stage of the self-organization process. [The study was supported by the Russian Foundation for Basic Research under Project No. 20-02-00493-a.]
Broadband operation of acoustic collimated beam source
Authors: Huang Sincheng , Pantea Cristian , Chillara Vamshi K. , Greenhall John
Published: June 2021

A low-frequency acoustic collimated beam (ACCObeam) source was recently developed by our team using the radial mode excitation of a piezoelectric disc. It relies on lateral clamping of the piezoelectric disc to produce a collimated sound beam while minimizing unwanted side lobes that occur for a free disc. ACCObeam has previously been explored and characterized for operation at the radial resonance frequencies; however, high-resolution ultrasound imaging requires broadband signals. We explore the characteristics of the broadband beam profile of ACCObeam. This requires beam profile characterization at multiple frequencies, typically incurring long measurement times. We investigate the possibility of characterizing beam profiles at multiple frequencies by exciting the ACCObeam with a broadband waveform such as a linear chirp or a Gaussian pulse. Subsequent post-processing can extract the beam profile for any specific frequency. In this talk, we present ACCObeam broadband measurements and compare them with both fixed-frequency measurements as well as numerical simulation. We also discuss the important parameters that affect the quality of beam profile characterization.
Acoustic manipulation of metallic particles for improved in-field material analysis
Authors: Davis Eric S. , Junghans Ann , Chavez Craig A. , Hakoda Christopher , Pantea Cristian
Published: June 2021

In-field material analysis is an important area of analysis, having the great advantage that the analytical measurement is performed at the site where the material is located, leading to faster and more informed decision making. This turns out to be very important for some very specific materials, such as high explosives or chemical/bio warfare agents, especially if the area to be inspected was thoroughly cleaned. The latter makes sample collection extremely difficult. However, regardless of how clean a surface is, trace amounts of the material of interest are still left behind. A combination of optical and acoustical methods that leads to improved detection efficiencies is presented. Surface-enhanced Raman spectroscopy (SERS) is a surface-sensitive technique that greatly enhances the Raman scattering by factors up to 1015, leading to detection down to the single molecule level. This technique requires very careful substrate preparation as well as very large spectroscopy equipment, which are not viable for infield analysis. In order to adapt SERS for in-field analysis, acoustic manipulation of metallic particles is used. Aggregation of particles on the surface of interest leads toa strong Raman enhancement factor, which will allow for much less sensitive handheld Raman instruments to be used in the field. Currently, preliminary results have achieved 103 enhancement, with much higher enhancement possible.
A noninvasive approach for temperature determination in confined Cyclotol
Authors: Pantea Cristian , Greenhall John , Zerkle David K. , Davis Eric S. , Chavez Craig A. , Broilo Robert M. , Zucker Jonathan M. , Shofner William S. , Blog Sarah L. , Vaughan Larry D.
Published: June 2021

Cyclotol is a melt-castable high explosive consisting of a mixture of RDX and TNT (75:25 wt. %). While used in conventional military applications, it can also be encountered in some types of IEDs (Improvised Explosive Devices). It is related to the more common Comp B (60:40 wt. %), and in the present work it was chosen as a case-study for noninvasive temperature determination in confined high explosives. An acoustics-based approach was used, based on (i) a collimated low-frequency acoustic beam, (ii) travel-time measurements of sound propagating along multiple paths, and (iii) sound speed-temperature inversion. Experiments were performed in a hermetically sealed cylindrical container with a volume of about 2 l, filled with casted Cyclotol. The container boundary temperature was varied between room temperature and ignition temperature. The experimentally determined acoustic temperature was in good agreement with other means of temperature measurements and finite-element modeling of temperature evolution in casted Cyclotol.
Applied hearing aids and signal processing for aural (re-)habilitation
Authors: Holt Rachael F.
Published: June 2021

Students who complete undergraduate aural (re-)habilitation courses in the speech and hearing science are generally interested in going into speech-language pathology, and in lower numbers, audiology, healthcare or education. A fundamental concept that students learn in this course is the applied relation among speech acoustics, signal processing, and hearing loss. I have incorporated an in-class hearing aid laboratory to provide students with the opportunity to (1) handle hearing aids, understand their components and accessories; (2) troubleshoot basic problems with hearing aids (e.g., dead battery, acoustic feedback) that they might encounter in clinical or educational settings (e.g., therapy session, classroom, nursing home, etc.); and (3) listen to hearing aids to determine what speech frequency ranges are influenced when settings are changed and how this relates to a listener’s hearing loss and their access to the speech spectrum. The lab is carried out in small groups with both current hearing aids and older models that allow students to change the frequency spectrum without a computer (e.g., screw sets that adjust the gain in specific frequency ranges), so that the lab can easily be completed in class following lectures introducing the material.
Lab kits for remote and socially distanced instruction in a GE Acoustics Course
Authors: Balant Anne C.
Published: June 2021

A lab kit that has been developed for teaching a general education acoustics course online has proven useful for socially distanced instruction in seated courses as well. This presentation will give an overview of the kit and experiences with adapting and using it to provide flexibility for students in all modalities of instruction during COVID-19.
Teaching speech acoustics with adaptable Praat labs
Authors: Siren Kathleen A.
Published: June 2021

Students identify and measure acoustic characteristics of vowel and consonant production in a series of labs utilizing Praat. The labs are particularly well-suited for synchronous Zoom classes with break out groups, but can be modified to be different lengths, to be completed asynchronously, and/or to be completed individually.
Compressional wave attenuation in muddy sediments at the New England Mud Patch
Authors: Holland Charles W. , Dosso Stan
Published: June 2021

A new method for measuring in situ compressional wave attenuation exploiting the spectral decay of Bragg resonances is applied to sediments at the New England Mud Patch. Measurements of layer-averaged attenuation in a 10.3 m mud layer yield 0.04 {0.03 0.055} dB/mi kHz (braces indicate outer bounds); the attenuation is twice as large at a site with 3.2 m mud thickness. Both results are strongly influenced by a ∼1 m sand-mud transition interval, created by geological and biological processes which mix sand (at the base of the mud) into the mud. Above the transition interval, homogeneous mud exhibits an attenuation 0.01–0.02 dB/m kHz, lower than that in the sand-mud transition interval by a factor of 10. Informed by these and additional observations, mud attenuation in and above the transition interval appears to be roughly spatially invariant across the area, explaining the factor of two in attenuation between the two sites by simple depth scaling. Further, the ubiquity of the processes that form the transition interval suggests that the scaling may be broadly applied to other muddy continental shelves. In principle, attenuation predictions in shallow water could be substantively improved with a modest amount of geologic and biologic information. [Research supported by ONR Ocean Acoustics.]
A discussion of the physical mechanisms of acoustic attenuation in the New England mud patch based on results of the Seabed Characterization Experiment
Authors: Pierce Allan D. , Mast T. Douglas
Published: June 2021

Experimental results for attenuation reported in connection with the Seabed Characterization Experiment 2017 are discussed and analyzed. Much of the results suggest attenuation depends on depth within a mud layer and that, over a wide frequency range, attenuation is nearly proportional to frequency. The present paper suggests that attenuation in mud is due almost entirely to localized processes, including (1) viscous flow (Stokes flow) around suspended sand particles, (2) sliding friction between particles, and (3) relaxation effects associated with breaking and re-association of bonds between clay particles. Present theories due to Buckingham and Chotiros and others are reviewed, and a fresh case is made for relaxation processes as a dominant contributor. Theoretical results show that a continuous smear of relaxation processes can account for a linear or power-law dependence of attenuation on frequency over a wide range, but excluding frequencies close to zero. Similar considerations apply to propagation of ultrasound in blood. All physically viable mechanisms will result in a frequency-squared dependence at low frequencies, but the dependence can change to linear dependence at frequencies slightly above zero. Theories based on Stokes flow around suspended sand particles can explain the dependence on porosity and on the number density of particle grains. Relaxation processes appear to be ubiquitous, and can be associated with diverse types of solid particles nominally touching each other, sliding, and separating.
BRUCE LINDSAY AWARD 2021: Likun Zhang
Authors: Zhang Likun
Published: June 2021

The R. Bruce Lindsay Award (formerly the Biennial Award) is presented in the Spring to a member of the Society who is no more than 10 years post terminal degree on 1 July at the time of Award acceptance and who, during a period of two or more years immediately preceding the award, has been active in the affairs of the Society and has contributed substantially, through published papers, to the advancement of theoretical or applied acoustics, or both. The award was presented biennially until 1986. It is now an annual award.
Helmholtz-Rayleigh Interdisciplinary Silver Medal in Physical Acoustics and Engineering Acoustics 2021: Michael R. Moldover
Authors: Moldover Michael R.
Published: June 2021

The Silver Medal is presented to individuals, without age limitation, for contributions to the advancement of science, engineering, or human welfare through the application of acoustic principles, or through research accomplishment in acoustics.
The internet goes quantum
Authors: Popkin Gabriel
Published: June 2021

A global network that would use quantum "entanglement" to weave intimate ties between far-flung users is beginning to take shape.
Tough hydrogels with rapid self-reinforcement
Authors: Liu Chang , Morimoto Naoya , Jiang Lan , Kawahara Sohei , Noritomi Takako , Yokoyama Hideaki , Mayumi Koichi , Ito Kohzo
Published: June 2021

Tougher when stressed

Hydrogels are typically weak materials because they contain only a small fraction of polymeric material highly swollen with water. Strength can be increased by adding extra cross-linking or interpenetrating networks with some sacrificial bonds to enhance toughness; however, these properties deteriorate upon stretching and may be slow to recover after relaxation. Liu
et al.
developed polyethylene glycol hydrogels cross-linked with moderate fractions of polymers that form sliding rings. These allow the chain to orient in parallel when stretched, leading to rapid and reversible strain-induced crystallization and thus much tougher hydrogels.

Science
, aaz6694, this issue p.
1078
Agricultural productivity must improve in sub-Saharan Africa
Authors: Jayne Thomas S. , Sanchez Pedro A.
Published: June 2021

The region must pivot from area expansion to increasing crop yields on existing farmland
Establishing gold and platinum standards to 1 terapascal using shockless compression
Authors: Fratanduono D. E. , Millot M. , Braun D. G. , Ali S. J. , Fernandez-Pañella A. , Seagle C. T. , Davis J.-P. , Brown J. L. , Akahama Y. , Kraus R. G. , Marshall M. C. , Smith R. F. , O’Bannon E. F. , McNaney J. M. , Eggert J. H.
Published: June 2021

Pushing a pressure standard

A challenge for understanding systems at extreme conditions is knowing the exact pressure at which exotic behaviors occur. This situation is caused by the lack of an absolute pressure-density relationship of standard pressure calibrants. Fratanduono
et al.
conducted a series of dynamic compression observations on platinum and gold to establish a high-pressure scale for these metals up to terapascal conditions (see the Perpsective by Jeanloz). This work provides a robust calibration when using these standards in high-pressure devices such as diamond anvil cells.

Science
, abh0364, this issue p.
1063
; see also abi8015, p.
1037
Fe-S cofactors in the SARS-CoV-2 RNA-dependent RNA polymerase are potential antiviral targets
Authors: Maio Nunziata , Lafont Bernard A. P. , Sil Debangsu , Li Yan , Bollinger J. Martin , Krebs Carsten , Pierson Theodore C. , Linehan W. Marston , Rouault Tracey A.
Published: June 2021

Mind your metals

Iron–sulfur clusters are important cofactors for proteins involved in metabolism and electron transfer but are also sometimes found in enzymes involved in transcription and replication of DNA. In vitro expression of such enzymes can result in faulty cluster assembly and confusion about the composition of the functional enzyme. Using a careful anoxic purification scheme, Maio
et al.
found that the severe acute respiratory syndrome coronavirus 2 RNA–dependent RNA polymerase contains two iron–sulfur clusters at two sites previously observed to bind zinc ions. Mutation of the ligating cysteine residues resulted in loss of polymerase activity. A less severe loss of activity was seen in the zinc-containing enzyme. Treatment with the nitroxide drug TEMPOL resulted in degradation of the clusters, enzyme inhibition, and inhibition of viral replication in cell culture.

Science
, abi5224, this issue p.
236
Thermonuclease seroinhibition test for distinguishing Staphylococcus aureus from other coagulase-positive staphylococci
Authors: Victor R , Lachica F , Jang S S , Hoeprich P D
Published: June 2021

Since coagulase-positive staphylococci from animals are heterogeneous, another test is necessary to distinguish Staphylococcus aureus from them. Staphylococcal thermonucleases appear to be heterogeneous; antisera raised against S. aureus isolated from humans inhibit thermonuclease activity as demonstrated by the metachromatic well-agar diffusion method. The serological specificity of the thermonuclease elaborated by S. aureus of human origin was demonstrated using three antisera and 407 strains of staphylococci from diverse human and animal sources.
Detection of group D and viridans streptococci in blood by radiometric methods
Authors: Beckwith D G
Published: June 2021

A prospective study was conducted to evaluate the radiometric detection of group D and viridans streptococci in blood, using three media preparations, Bactec 6A and 6B isotonic media and 8B hypertonic medium. All enterococci tested were detected by the 6A and 6B media. However, the 6A medium failed to detect 76% of the Streptococcus bovis isolates and 57% of the viridans streptococci, whereas all S. bovis isolates and 95% of the viridans streptococci were detected with the 6B formulation. No improvement in detection was noted in comparing the 6B and the 8B hypertonic media. The importance of adequate detection of this group of organisms, especially in patients with endocarditis, is discussed.
Characterization of a Haemophilus paracuniculus isolated from gastrointestinal tracts of rabbits with mucoid enteritis
Authors: Targowski S , Targowski H
Published: June 2021

The isolation, characterization, and identification of a microorganism isolated from gastrointestinal tracts of rabbits with mucoid enteritis are described. The isolated organism did not grow on standard media. This organism grew around colonies of Staphylococcus aureus and Lactobacillus desidiosus and around disks saturated with diphosphopyridin nucleotide (factor V) on brain heart infusion agar. The growth of this organism was also observed on media supplemented with beta-nicotinamide adenine dinucleotide. The organism appeared as gram-negative, pleomorphic rods or coccobacilli. It was positive for urease, oxidase, catalase, glycosidases, porphyrin, and indole, and it fermented glucose and sucrose. All of these characteristics suggest that the organism is a member of the genus Haemophilus. Because of its isolation from rabbits and differences in some characteristics from other species of this genus, the name Haemophilus paracuniculus is proposed for this organism.
Adaptation of the staphylococcal coagglutination technique for detection of heat-labile enterotoxin of Escherichia coli
Authors: Brill B M , Wasilauskas B L , Richardson S H
Published: June 2021

Protein A-containing staphylococci coated with specific antiserum were tested for heat-labile enterotoxin of Escherichia coli. The immunological cross-reactivity of E. coli heat-labile enterotoxin with Vibrio cholerae toxin (choleragen) was the basis for sensitizing stabilized suspensions of the Cowan I strain of Staphylococcus aureus with anticholeragen. Unconcentrated culture supernatant fluid containing E. coli heat-labile enterotoxin produced macroscopic agglutination when mixed with sensitized staphylococci in capillary tubes. A total of 15 toxigenic and 61 nontoxigenic isolates were tested by the staphylococcal coagglutination technique in a coded fashion and found to be in agreement with previous results of the Chinese hamster ovary cell assay and the passive immune hemolysis test. The staphylococcal coagglutination technique is simple, relatively inexpensive to perform, and requires the immunoglobulin fraction of anticholeragen as the only specific reagent. The staphylococcal coagglutination technique appears to have potential for routine use in diagnostic microbiology laboratories.
Improved laboratory efficiency and diagnostic accuracy with new double-lumen-protected swab for for endometrial specimens
Authors: Pezzlo M T , Hesser J W , Morgan T , Valter P J , Thrupp L D
Published: June 2021

Intrauterine specimens were obtained from 22 patients with endometritis and 24 control patients following cesarean section by using both a new protected swab and a standard anaerobic swab. The protected swab improved the value of the direct smear and Gram stain, resulted in fewer false-positive cultures, better defined endometrial flora in patients with endometritis, and permitted major savings in laboratory personnel time and materials.
Factors Affecting Isolation and Identification of
Haemophilus vaginalis (Corynebacterium vaginale)
Authors: Bailey Robert K. , Voss Jack L. , Smith Rodney F.
Published: June 2021

The rate of isolation of organisms resembling
Haemophilus vaginalis (Corynebacterium vaginale)
from vaginal specimens was not significantly affected by anaerobic versus carbon dioxide incubation atmospheres or whether specimens were inoculated on isolation media immediately after collection or after a delay of 6 h. Forty-one clinically isolated strains were provisionally divided into 30
H. vaginalis
strains and 11
H. vaginalis
-like (HVL) strains based on morphological and growth characteristics. The
H. vaginalis
strains were less reactive in API-20A identification test strips, (Analytab Products, Inc.) using Lombard-Dowell broth, than in a modified basal medium that contained proteose peptone no. 3 (Difco). The numbers and kinds of substrates fermented by 30 clinical and 2 reference strains of
H. vaginalis
varied among conventional, API, Minitek (Baltimore Biological Laboratory), and rapid buffered substrate fermentation systems. A greater number and variety of carbohydrates were fermented by the 11 HVL strains more consistently in all four test systems. Analysis of volatile and nonvolatile fermentation end products by gas-liquid chromatography did not reveal significant differences between the
H. vaginalis
and HVL strains. However, the latter group grew in peptone-yeast extract-glucose broth, whereas the
H. vaginalis
strains did not grow without the addition of starch to peptone-yeast extract-glucose. All of the reference and clinical strains were similar in their susceptibilities to a variety of antimicrobial compounds except sulfonamides, which inhibited the HVL strains and bifidobacteria but not the
H. vaginalis
strains. Sulfonamide susceptibility or resistance corresponded in part to the
H. vaginalis
and HVL-bifidobacteria strain reactions on selected conventional fermentation substrates. Susceptibility or resistance to sulfonamides and metronidazole in conjunction with fermentation tests is described to aid in the separation of
H. vaginalis
from other possibly unrecognized biotypes of
H. vaginalis
or other vaginal bacteria that presumptively resemble the organism. A human blood medium known as V agar was also of considerable value in distinguishing
H. vaginalis
from HVL strains, because only the
H. vaginalis
strains produced diffuse beta-hemolysis on V agar.
Canine kidney cell line for isolation of respiratory viruses
Authors: Meguro H , Bryant J D , Torrence A E , Wright P F
Published: June 2021

By means of a continuous canine kidney cell line (MDCK), influenza viruses were rapidly isolated from specimens collected from patients with respiratory disease. The cell line proved more sensitive than either eggs or rhesus monkey cells for currently circulating influenza A and B strains. Influenza viruses caused a distinct cytopathology within 5 days of inoculation if trypsin-ethylenediamine-tetraacetic acid was incorporated into the medium. Sufficient hemagglutinin was produced on the initial tissue culture passage to allow direct identification of isolates by hemagglutinin inhibition tests. A variety of other respiratory viruses replicated in MDCK, and over a 10-month period 211 of 600 specimens (35%) yielded viruses.
Detection of enteric campylobacteriosis in children
Authors: Bokkenheuser V D , Richardson N J , Bryner J H , Roux D J , Schutte A B , Koornhof H J , Freiman I , Hartman E
Published: June 2021

Campylobacter fetus subsp. jejuni was recovered as the sole bacterial pathogen from 31% of 0- to 8-month-old children with acute gastroenteritis and from 5% of asymptomatic children (P less than 0.05). In children 8 to 24 months old, the respective recovery rates were 38 and 40%. With the exception of one case of simultaneous bacteremia, the clinical course of the symptomatic infection was benign and rarely lasted more than a week. The isolates were sensitive to most commonly used antibiotics. Several isolates shared antigenic determinants with C. fetus subsp. intestinalis. A bacteriophage specific for C. fetus subsp. jejuni lysed 73% of the strains. Several phage-resistant isolates carried a phage that lysed the stock strain of C. fetus subsp. jejuni (NADC 917).
Halophilic, lactose-positive Vibrio in a case of fatal septicemia
Authors: Mertens A , Nagler J , Hansen W , Gepts-Friedenreich E
Published: June 2021

A halophilic Vibrio species was isolated from blood cultures from a 59-year-old male with enteritis. The strain differed from Vibrio parahaemolyticus and Vibrio alginolyticus by its ability to ferment lactose, its production of beta-galactosidase, and its lower NaCl tolerance. A report of this infection and a description of the isolate is presented.
Laboratory evaluation of amikacin susceptibility testing by the AutoBac I system
Authors: Boughton W H , Berman S J , Boughton M T
Published: June 2021

A total of 319 clinical isolates were compared for amikacin susceptibility by AutoBac I and Bauer-Kirby disk diffusion methods. There was an overall agreement of 98.5% between AutoBac I and Bauer-Kirby. An additional 23 strains resistant to amikacin, obtained from Bristol Laboratories, registered a 65% overall agreement. The sensitivity readings differed between the two methods for 13 organisms: 11 were minor discrepancies, intermediate by one of the two methods, and 2 were very major discrepancies, resistant by disk diffusion and susceptible by AutoBac I.
Biochemical characteristics of 130 recent isolates from Haemophilus influenzae meningitis
Authors: Kilian M , Sørensen I , Frederiksen W
Published: June 2021

A total of 130 Haemophilus strains, comprising virtually all isolates from Danish and Norwegian cases of Haemophilus meningitis occurring in the period from October 1975 through September 1976, were examined by biochemical and serological means. All isolates were identified as H. influenzae and, except for one noncapsulated strain, possessed a capsule of serotype b. The vast majority of strains (93%) belonged to biotype I, which, in contrast to biotypes II and III, is rarely encountered as a commensal of the upper respiratory tract. This finding is a strong incentive for studies of possible additional virulence factors associated with biotype I organisms. The results are discussed in the light of North American reports, which have suggested changes in the etiology of Haemophilus meningitis.
Rapid and Inexpensive Microcapillary Immunodiffusion Assay Technique
Authors: Wagstaff Paul A.
Published: June 2021

A simple, rapid, and inexpensive single-gel immunodiffusion technique requiring but 1 μl of sample for analysis and an incubation period of only 2 h is described.
Assay of human interferon in Vero cells by several methods
Authors: Ferreira P C , Peixoto M L , Silva M A , Golgher R R
Published: June 2021

Four methods for the assay of human interferon in Vero cells were compared based on the inhibition of viral cytopathic effect (CPE) in tubes, the inhibition of CPE in microplates, the reduction of plaques, and the inhibition of quantitative hemadsorption. For inhibition of CPE, Sindbis virus, vesicular stomatitis virus, poliovirus type 2, and vaccinia virus were used for challenge. In the plaque reduction method, Sindbis virus, vesicular stomatitis virus, and poliovirus were employed, and Newcastle disease virus was used in the quantitative hemadsorption assay. Sindbis virus was most susceptible to interferon in those tests measuring inhibition of CPE, but vesicular stomatitis virus was as sensitive in the plaque reduction method. Highest titers of interferon were recorded in microplates, especially with Sindbis virus as the challenge agent, followed by the quantitative inhibition assay. The CPE inhibition method was the simplest, and the quantitative hemadsorption assay was the most rapid to perform. Reproducibilities, as shown by the coefficient of variation, were 15, 39, and 59% for plaque reduction, CPE inhibition in tubes, and CPE inhibition in microplates, respectively.
Diarrhea and rotavirus infection associated with differing regimens for postnatal care of newborn babies
Authors: Bishop R F , Cameron D J , Veenstra A A , Barnes G L
Published: June 2021

Surveillance of 2,041 babies born during 4 winter months in one obstetric hospital in Melbourne, Australia, showed that 215 developed acute diarrhea during the first 2 weeks of life. Babies requiring special care from birth had a high incidence of sporadic diarrhea (36%). The incidence of diarrhea among healthy full-term babies was low if they were "rooming-in" with their mothers (2 to 3%) but high if they were housed in communal nurseries (29%). The most important factor influencing incidence of diarrhea was proximity to other newborn babies and frequency of handling by related adults. Breast feeding did not always protect babies from diarrhea. Excretion of rotaviruses was temporally retlated to diarrhea in 61 to 76% of healthy full-term babies and in 44% of babies requiring special care. Other eneteric pathogens, including enerotoxigenic Escherichia coli, were occasionally isolated. Calculation of the ratios of symptomatic to asymptomatic infection suggests that babies requiring special care are much more likely to develop symptomatic illness after rotavious infection than are full-term babies.
Evaluation of the modified API 20C system for identification of clinically important yeasts
Authors: Buesching W J , Kurek K , Roberts G D
Published: June 2021

The modified API 20C system (Analytab Products, Inc.) containing 19 carbohydrate assimilation tests was used to identify stock cultures of clinical isolates and routine clinical isolates from the Mayo Clinic mycology laboratory. The system provided correct identifications for 96% of the 505 organisms tested. The API 20C represents a commercial system useful for the identification of yeasts from clinical specimens. Although reliable, it is not a complete system and must be used in conjunction with microscopic morphological features for definitive identification. Since the system requires 72 h for identification, it is not designed for the rapid presumptive identification of such organisms as Cryptococcus neoformans; other biochemical tests must be used for this purpose.
Comparative serology of two clinical isolates of Bacteroides fragilis and Bacteroides thetaiotaomicron
Authors: Landay M E , Baldwin W
Published: June 2021

Antiserum prepared in rabbits against Bacteroides fragilis showed numerous bands when reacted with B. fragilis antigen in Ouchterlony plates. This antiserum also reacted with Bacteroides thetaiotaomicron and showed one band of apparent identity with B. fragilis. The band of identity common for both organisms was lost if the antigen was heated at 80 degrees C for 30 min. Antisera prepared against B. thetaiotaomicron did not react with B. fragilis.
Antigen requirements, sensitivity, and specificity of enzyme immunoassays for measles and rubella viral antibodies
Authors: Forghani B , Schmidt N J
Published: June 2021

Enzyme immunoassay (EIA) systems for measles virus and rubella virus were studied from the standpoints of requirements for suitable viral antigens and control antigens, and the sensitivity and specificity of the tests for detecting antibody elicited by past infection (determination of immunity status), and for serodiagnosis of currenet infections. Crude or semipurified measles virus antigens were satisfactory for EIA, but antigens derived by pelleting virus from infected cell culture fluids were slightly more specific in their reactivity than were antigens produced from lysates of infected cells. However, reliable rubella EIA antigens could be produced only from infected cell culture fluids, and they required density gradient purification to render them suitably specific. Even with gradient-purified rubella antigens, it was necessary to use antigen prepared in an identical fashion from uninfected cell culture fluids as a control on the specificity of reactions obtained with test sera. With appropriate viral antigens and control antigens, both measles and rubella EIA systems were highly sensitive and specific for determination of immunity status and for serodiagnosis of current infections. Antibody was detectable earlier in the course of infection by EIA than by hemagglutination inhibition or complement fixation, but this did not limit the diagnostic value of the test, since titer increases demonstrable by EIA were usually greater than those detectable by hemagglutination inhibition or complement fixation tests.
Isolation and characterization of a polyene-resistant variant of Candida tropicalis
Authors: Merz W G , Sandford G R
Published: June 2021

An atypical variant of Candida tropicalis was recovered from multiple specimens from a patient who had been a recipient of a bone marrow transplant. This yeast variant showed atypical morphology on corn meal agar distinguishable from typical isolates of C. tropicalis by the production of clusters of blastospores. Isolates of the variant produced acid, but no gas, from maltose and sucrose in fermentation tests. Isolates from blood, pleural fluid, respiratory secretions, and stool specimens were susceptible to amphotericin B and nystatin in an agar dilution system. However, eight isolates of the variant C. tropicalis recovered over a period of 4 weeks from the patient's urine after amphotericin B therapy were found to be resistant to amphotericin B and nystatin. The isolate recovered after 7 days of therapy had minimal inhibitory concentrations of 100 micrograms of amphotericin B and 20 micrograms of nystatin per ml, whereas the seven isolates recovered subsequently had minimal inhibitory concentrations of greater than 500 micrograms of amphotericin B and 50 micrograms of nystatin per ml. The resistant isolates concomitantly lost the capacity to utilize amino acids that susceptible isolates could utilize. Ultraviolet absorption spectra of nonsaponifiable fractions of whole cells showed that resistant isolates lacked ergosterol, which susceptible isolates contained.
Characterization of a screening test for diphtherial toxin antigen produced by individual plaques of corynebacteriophages
Authors: Welkos S L , Holmes R K
Published: June 2021

A passive immune hemolysis assay has been developed to detect diphtherial toxin produced in individual plaques of tox+ corynebacteriophages. This assay permits rapid screening of large numbers of corynebacteriophages for their ability to code for diphtherial toxin or related antigens. The specificity of the assay and its potential usefulness for genetic studies of toxinogenesis have been demonstrated with well-characterized tox+ and tox- laboratory strains of corynebacteriophages.
Isolation of Mycoplasma bovis from a patient with systemic illness
Authors: Madoff S , Pixley B Q , DelGiudice R A , Moellering R C
Published: June 2021

Mycoplasma bovis was cultured from the sputum of a patient with lobar pneumonia, psychosis, and probable myocarditis, nephritis, and hemolytic anemia. Although we cannot be certain that this species of mycoplasma was the etiological agent of the patient's acute illness, this case report is of interest because, to the best of our knowledge, it represents the first isolation of M. bovis from a human source.
Plaque assay and improved yield of human coronaviruses in a human rhabdomyosarcoma cell line
Authors: Schmidt O W , Cooney M K , Kenny G E
Published: June 2021

Propagation and plaque assay of human coronavirus prototypes were studied in two human cell lines: a diploid fetal tonsil (FT) and a heteroploid rhabdomyosarcoma (RD) cell lines. Plaques, observed within 2 to 3 days on FT cell monolayers with both 229E and OC43 viruses, appeared as colorless areas after staining with neutral red or crystal violet, whereas neutral red staining was required for visualization of plaques on RD cells. The plating efficiencies were approximately equal between the two cell lines, but virus assay by plaque formation was 15- to 30-fold more efficient than tube dilution assay with 50% endpoints. The discrepancy between 50% endpoint and plaque-forming unit values was striking and appeared to result from the fact that killing of cells (particularly RD cells) by coronaviruses was not accompanied by visible changes in the cells but killing was detected by the failure of infected cells to stain with a vital dye. The latent phase in one-step growth curves was 5 to 6 h for both viruses in either cell line, but the maximum yield of intracellular virus was reached in 18 to 20 h for FT cells and 24 to 28 h for RD cells. Virus release also differed between the two cell lines: in FT cells, the maximum yield of extracellular virus was reached 2 to 3 h later than that of intracellular virus, whereas in RD cells, the difference was 5 h for 229E virus and 10 h for OC43 virus. Although both cell lines appear equally useful for plaque assay, RD cells would be preferred for mass virus propagation because yields (5 X 10(8) plaque-forming units per ml) were 10-fold higher than in FT cells, a finding true for both virus prototypes.
Short artificial hairpins sequester splicing signals and inhibit yeast pre-mRNA splicing
Authors: Goguel V , Wang Y , Rosbash M
Published: June 2021

To examine the stability of yeast (Saccharomyces cerevisiae) pre-mRNA structures, we inserted a series of small sequence elements that generated potential RNA hairpins at the 5' splice site and branch point regions. We analyzed spliceosome assembly and splicing in vitro as well as splicing and nuclear pre-mRNA retention in vivo. Surprisingly, the inhibition of in vivo splicing approximately paralleled that of in vitro splicing. Even a 6-nucleotide hairpin could be shown to inhibit splicing, and a 15-nucleotide hairpin gave rise to almost complete inhibition. The in vitro results indicate that hairpins that sequester the 5' splice site have a major effect on the early steps of spliceosome assembly, including U1 small nuclear ribonucleoprotein binding. The in vivo experiments lead to comparable conclusions as the sequestering hairpins apparently result in the transport of pre-mRNA to the cytoplasm. The observations are compared with previous data from both yeast and mammalian systems and suggest an important effect of pre-mRNA structure on in vivo splicing.
Labyrinth patterns in Magadi (Kenya) cherts: Evidence for early formation from siliceous gels
Authors: Leet Kennie , Lowenstein Tim K. , Renaut Robin W. , Owen R. Bernhart , Cohen Andrew
Published: June 2021

Sedimentary cherts, with well-preserved microfossils, are known from the Archean to the present, yet their origins remain poorly understood. Lake Magadi, Kenya, has been used as a modern analog system for understanding the origins of nonbiogenic chert. We present evidence for synsedimentary formation of Magadi cherts directly from siliceous gels. Petrographic thin-section analysis and field-emission scanning electron microscopy of cherts from cores drilled in Lake Magadi during the Hominin Sites and Paleolakes Drilling Project in 2014 led to the discovery of two-dimensional branching “labyrinth patterns” in chert, which are a type of fractal “squeeze” pattern formed at air-liquid interfaces. Labyrinth patterns preserved in chert from Lake Magadi cores indicate invasion of air along planes in dewatering gels. These patterns support the precipitation of silica gels in the saline-alkaline Lake Magadi system and syndepositional drying of gels in contact with air as part of chert formation. Recognizing cherts as syndepositional has been critical for our use of them for U-Th dating. Identification of labyrinth patterns in ancient cherts can provide a better understanding of paleoenvironmental and geochemical conditions in the past.
Morphological selectivity of the Permian-Triassic ammonoid mass extinction
Authors: Dai Xu , Korn Dieter , Song Haijun
Published: June 2021

Ammonoids suffered a diversity bottleneck during the Permian-Triassic mass extinction (PTME) and experienced a rapid diversification in the Early Triassic. However, the kinds of ammonoids that were more likely to survive the PTME and that fueled subsequent diversification are still poorly known. We compiled a comprehensive morphological data set and used the nonmetric multidimensional scaling method to reveal the impact of the PTME on the morphological selectivity of ammonoids. Our results show that postextinction taxa occupied a quite different morphospace when compared with the pre-extinction assemblages. The survivors were mainly smooth and weakly ornamented forms, while the late Permian species were dominated by coarsely ornamented forms. Contrary to previously recognized nonselective patterns, these results suggest a morphological selectivity of the Permian-Triassic crisis. Newcomers in the Griesbachian were mainly compressed and smooth forms. This morphological shift from the coarsely ornamented ammonoids dominating the Changhsingian to the smooth ammonoids dominating the Griesbachian possibly suggests an ecological turnover of ammonoids during the PTME.
Anisotropy-revealed change in hydration along the Alaska subduction zone
Authors: Lynner Colton
Published: June 2021

Megathrust earthquake behavior in subduction zones is controlled by a variety of factors including the hydration state of the subducting slab. Increased hydration reduces the occur-rence of great, damaging earthquakes by diminishing the strength of the material along the interface between tectonic plates. Understanding variations in hydration in subductions zones is necessary for properly assessing the overall hazard posed by each region. Fortunately, seismic anisotropy is strongly dependent upon hydration of the subducting crust and litho-sphere. I present shear-wave splitting measurements that illuminate changes in anisotropy, and therefore hydration, of the subducting Pacific plate beneath the Alaska subduction zone (northern Pacific Ocean). Variations in shear-wave splitting directly correlate to changes in the behavior of great, megathrust earthquakes. My measurements show that the Shumagin seismic gap is characterized by a hydrated subducting slab, explaining the long-term lack of great earthquakes. Observations in the immediately adjacent Semidi segment, which experiences great events regularly, indicate a far less hydrated slab. These results are driven by the preferential alignment of paleo-spreading fabrics of the Pacific plate. Where fabrics are more closely aligned with the orientation of the trench, outer-rise faulting and plate hydration is enhanced. These results highlight the importance of changes in preexisting slab structures and subsequent hydration in the production of great, damaging earthquakes.
Supplemental Material: Quaternary chronology and rock uplift recorded by marine terraces, Gaviota coast, Santa Barbara County, California, USA
Authors: Morel Daniel L. , Morell Kristin D. , al. et
Published: June 2021

Details of luminescence dating methods and results.
Fluorescence Quenching of 3,5-Diphenyl-8-CF3-BODIPY Luminophores Bearing Aminophenyl Substituents by Aromatic Molecules
Authors: Gadomska A. V. , Nevidimov A. V. , Tovstun S. A. , Petrova O. V. , Sobenina L. N. , Trofimov B. A. , Razumov V. F.
Published: June 2021

It has been found that the fluorescence quantum yield of 3,5-diphenyl-8-CF3-BODIPY luminophores with aminophenyl substituents in aromatic solvents strongly depends on the position of the aniline amino group with respect to the position of attachment to the core of the BODIPY molecule. It has been suggested and substantiated that the reason for quenching of BODIPY meta-isomers is the specific interaction of luminophore molecules with aromatic molecules.