bluuebunny/crossref_metadata_2025 huggingface dataset:
The Static Response of Axisymmetric Conical Shells Exhibiting Bistable Behavior
Authors: Luxenburg Yair , Givli Sefi
Published: June 2021

Belleville springs are widely used in a variety of mechanical systems. Recent advances in the field of multi-stable structures suggest that these conical axisymmetric washers may be extremely useful as bistable building blocks for multi-stable architected metamaterials. In this paper, we examine the ability of existing analytical models to accurately predict the bistable behavior of Belleville springs, namely, a nonmonotonous force–displacement relation with two branches of positive stiffness separated by a branch of negative stiffness. By comparing with results of finite element (FE) simulations, we find that current analytical models may suffer from significant inaccuracies associated with the assumption of rigid rotation. According to this assumption, adopted by all analytical models of Belleville springs, the cross section of the spring rotates without bending, i.e., maintains zero curvature as the spring deforms. Motivated by this insight, we relax the rigid-rotation assumption and approximate the radial displacement field by a linear relation in terms of the distance from the spring axis. We find, based on extensive finite element simulations, that the functional dependence of the radial displacement on the geometry of the springs is indifferent to the stage of deformation and can be expressed in terms of three geometrical parameters. These findings enable us to derive closed-form expressions that are simple and straightforward to use, yet are significantly more accurate than existing analytical models.
Safety Integrity Level (SIL) Allocation on Monorail Rolling Stock
Authors: Li James
Published: June 2021

Railroad and transit projects are increasingly referencing and requiring compliance with the CENELEC railway standards, and the Independent Safety Assessment (ISA) is a key element of the safety certification and homologation process. The Quantitative Risk Analysis (QRA) which includes the Safety Integrity Level (SIL) allocation to the Safety Functions (SFs) is one of the major elements in the development of a Safety Management System (SMS) for the railroad and transit systems. This paper presents the experience with SIL allocation to the Safety functions designed on the Monorail Rolling Stock, which is essential for the Safety Management System to be successful in delivering IEC 61508 / CENELEC standards (EN 50126/8/9) based railroad and transit systems.

This paper introduces the concept of SIL, interpretation of SIL in the different standards such as IEC61508, EN50126, EN50128 and EN50129; methods of defining Tolerable Hazard Rate, ALARP principle, and experience of SIL allocation on the Monorail Rolling Stock. The study of SIL allocation on the Monorail Rolling Stock comprises of the characteristics of the Monorail system, general approach of SIL allocation, functional analysis, identification of required SIL, example discussion, assignment of safety functions to systems, and the identification of alternate risk reduction measures. The conclusion is summarized at the end of the paper.
Hybrid Rail Technology Review: an Intermediate Pathway For Electrifying the Freight and Commuter Rail Sector - a Technical and Operational Assessment
Authors: Barbosa Fábio C.
Published: June 2021

The transport industry, as any other sector, has been permanently challenged by both the continuously stringent environmental standards and the energy efficiency requirements, which has driven a set of initiatives focused on both the fuel burn reduction and the environmental performance improvement. The rail sector currently relies on the efficient and local zero emission electrical traction for the medium to heavy density corridors. However, for the light to medium density corridors (both passenger and freight), given the high upfront costs associated with the electrical infrastructure, they are currently required to rely on fossil fuel based traction (often, the diesel-electric) architecture, with an inherent efficiency and environmental burden. The advent of hybridization, i.e. the use of more than one power source in a powertrain (mainly — but not restricted to — an internal combustion engine (ICE) and electric motors (EM), associated with an electrical energy storage device - ESD) — currently a feasible approach for the automotive sector — has opened the way for the rail industry, as an opportunity to improve the energetic efficiency and reduce the environmental footprint for the aforementioned low to medium density rail corridors, without the cost burden of an electrical infrastructure. The hybrid powertrain efficiency drivers are basically: i) kinetic energy recovery, through the use of the regenerative braking (i.e. using electric motors as generators, to recover part of the train’s kinetic energy); ii) improved engine performance, avoiding the low efficiency (low load) engine range and iii) engine downsizing (engine power requirement reduction, as it is assisted by the electric traction on power bursts). From an environmental perspective, the reduced fuel consumption also means lower emissions. Moreover, hybrid configurations might also reduce noise and gaseous engine emissions within/nearby stations or urban rail yards, by switching off internal combustion engines, running the train and powering auxiliary systems with the previously stored electrical energy on the ESD. Finally, for electrified rail lines, the hybrid rail configuration might also provide the so called last mile capability, used to circumvent non electrified rail stretches, like bridges or tunnels, as well as small extension non electrified rail segments.

This work presents a review of hybrid rail technology, covering hybrid configuration and energy storage devices, from both a technical, operational and environmental perspective, supported on current available technical literature, as well as on simulation and field test reports, followed by a near to mid term outlook of hybrid rail technology for both freight and passenger segments.
Energy Harvesting Device for Powering Onboard Condition Monitoring Modules in Rail Service
Authors: Amaro Martin , Tarawneh Constantine , Foltz Heinrich , Garcia Roberto A.
Published: June 2021

Rail transportation plays an important role in today’s economy by delivering a large quantity of goods and passengers to various locations throughout North America in an economic and efficient manner. Bearing failure is one of the leading causes of derailments that result in significant capital loss and in extreme cases tragic human loss. The two widely used bearing health monitoring systems are the Trackside Acoustic Detection System (TADS™) and the wayside Hot-Box Detector (HBD). These systems are reactive in nature and only give alerts when the bearings are nearing failure. To supplant that, a prototype wireless onboard condition monitoring system was developed by researchers at the University Transportation Center for Railway Safety (UTCRS). This onboard wireless system can detect bearing defects at their early stages of initiation so that proactive maintenance actions can be taken by the railroads and railcar owners. Due to the wireless nature of this system, a constant power supply is needed to ensure its continued operation.

Currently, the prototype wireless system utilizes low-power circuitry that is powered by a rechargeable AA battery that can provide up to two years of operation depending on usage. Implementation of a suitable energy harvesting device can significantly increase the longevity of the batteries used in the wireless module, and in ideal operating conditions, generate consistent energy rendering the battery as a temporary energy storage device. The proposed energy harvesting device consists of thermoelectric generators, aluminum heat sinks, a switching boost convertor, and a battery management chip. This device was tested on a dynamic bearing test rig to assess the performance of the thermoelectric generators. To best simulate field operation conditions, the thermoelectric generators were placed on opposite sides of the bearing adapter; one exposed to direct forced convection while the other side is shielded by the adapter and experiences minimal convection. Thermoelectric generators were found to be an effective solution due to their ability to convert a temperature gradient into a usable voltage sufficient to charge the battery. The buck booster converter increases the voltage from the thermoelectric generators to 5-volts so that the battery management chip can regulate the voltage and efficiently charge the battery. This paper summarizes the performance of the thermoelectric modules under different operating conditions. The main goal of this project is to devise an energy harvesting device that allows the wireless module to be self-powered utilizing the heat generated from the bearing and the charge held by the battery as a hybrid power source.
Stabilization of Railroad Ballast Using Polyurethane Under Various Coal Fouling Conditions
Authors: Gundavaram Dinesh , Hussaini Syed Khaja Karimullah
Published: June 2021

This paper presents a comparative study on the shear behavior of coal fouled polyurethane-stabilized and polyurethane-stabilized coal fouled ballast. Fresh ballast and coal fines of mean particle sizes (D50) of 42 mm and 545 microns, and Elastan polyurethane polymer with a density of 1100 kg/m3 were used in the current study. Tests were conducted at normal stress (σn) varying from 60–120 kPa and at rate of shearing (Sr) 3 mm/min. To mimic the effect of coal fouling, a predetermined amount of coal was added that signifies a fouling level, of 30% void contamination index (VCI), in the present study. Test results highlighted that polyurethane stabilization technique enhanced shear stress of ballast. However, the coal fouling reduced the shear stress of polyurethane-stabilized and unstabilized ballast. The friction (φ) and dilation (ψ) angles of polyurethane-stabilized and unstabilized ballast were found to reduce non-linearly with an increase in σn. Furthermore, the values of φ and ψ of unstabilized ballast reduced from 65° to 60° and 21° to 16°, respectively due to coal fouling. The stabilization efficiency factor (Sef), stated as the ratio of the shear stress of stabilized ballast to the unstabilized ballast, differs from 1.70 to 1.75 for polyurethane-stabilized ballast as σn varies from 60 to 120 kPa. Moreover, it is observed in coal fouling conditions that the coal fouled polyurethane-stabilized ballast (FPSB) shown better performance when compared to polyurethane-stabilized coal fouled ballast (PSFB).
An Evaluation of Derailment Mechanics and Derailment Analysis Methodologies
Authors: Kirkpatrick Steven W.
Published: June 2021

Detailed analyses of vehicle and train collisions are a common part of new vehicle design projects. It is relatively simple to describe appropriate collision scenarios for a train and the resulting collision mechanics are reasonably controlled if the trains remain upright and in-line. These scenarios are well suited to advanced dynamic finite element simulation codes.

Alternatively, train derailment analyses are less common and have unique characteristics that make the analyses difficult. The derailment event can involve the interaction of many cars and have a relatively long duration compared to other crash events. Freight derailments can involve trains in excess of 100 cars long and the duration of the derailment response can be on the order of a minute before coming to rest. Further complicating the analysis are the many parameters that are not well characterized or controlled. The motions of rail cars after leaving the tracks are not well known and difficult to model. The wheels and trucks can plough through ground or remaining track sections. The material properties and geometry of the ground can have large variations and are typically not well known or characterized for specific derailment events. Additionally, the geometry of the surrounding terrain can have a wide range of variability at derailment sites.

As a result of these complexities, there are far fewer standardized methodologies used for the analysis of derailments. The detailed finite element models are applied in some cases, but the computational requirements to model these events in high fidelity are quite high.

This paper provides a review of some past derailment modeling efforts and recent investigations and analyses of derailment events to provide insights into the derailment mechanics of freight trains. The objective is to assess the relative magnitudes of effects such as the braking characteristics, brake application delay time, and blockage force caused by the derailed and overturned cars on the subsequent deceleration of the trailing cars on the rail.
Protective effects of S-sulfonated human gamma globulin against experimental infections in mice
Authors: Tomioka H , Iwamura Y , Suzuki Y , Ohtomo S , Hashimoto Y
Published: June 2021

S-sulfonated gamma globulin (GGS), newly developed as a safe drug for intravenous use, was studied for its protective effects against some experimental infections in mice. Gamma globulin showed a good protective activity against infections due to Streptococcus pneumoniae and Escherichia coli and was moderately active against infections due to Staphylococcus aureus and Pseudomonas aeruginosa. In most cases, the potency of GGS was almost the same as that of original native gamma globulin. The duration of GGS activity in vivo was found to be comparable to that of native gamma globulin and much higher than that of pepsin-digested gamma globulin. In the control of infection due to E. coli, specific antibody was found to play a central role in the antibacterial action of GGS. When GGS was administered in combination with the antibiotics gentamicin and cefazolin for the control of infections due to S. pneumoniae or E. coli, a clear synergistic effect was observed.
Improved protection against cholera in adult rabbits with a combined flagellar-toxoid vaccine
Authors: Resnick I G , Ford C W , Shackleford G M , Berry L J
Published: June 2021

Ligated ileal loops of adult rabbits were used to evaluate the prophylactic potential against cholera of a combined vaccine consisting of toxin-free crude flagella (CF) and glutaraldehyde-derived cholera toxoid (TV). The resulting fluid accumulation ratios were compared with those in rabbits immunized with saline (controls) and with CF and TV alone. Data for single vaccines confirmed the superior protection effect of CF over TV. In rabbits vaccinated with both CF and TV, maximal fluid accumulation ratios were not obtained with a challenge dose as high as 5 X 10(9) colony-forming units (CFU). Two rabbits similarly immunized failed to produce positive loops with challenges of 6.3 X 10(8) and 5 X 10(9) CFU, respectively. The vibriocidal titer of serum from rabbits immunized with a killed commercial vaccine in addition to those listed above was determined at intervals for a period of 164 days. No vibriocidal activity was detected in serum of control rabbits and of rabbits vaccinated with TV. Serum from animals given CF or commercial vaccine had similar vibriocidal titers even when the test bacteria were nonflagellated. Protection against challenge as evaluated by ileal loops did not, however, correlate with vibriocidal titer.
Effect of carbohydrates on adherence of Escherichica coli to human urinary tract epithelial cells
Authors: Schaeffer A J , Amundsen S K , Jones J M
Published: June 2021

Adherence of Escherichia coli cells to voided uroepithelial cells from healthy women was measured by use of [3H]uridine-labeled bacteria filtered through a polycarbonate membrane filter (5-micrometer pore size). At a concentration of 2.5% (wt/vol), D-mannose, D-mannitol, alpha-methyl-D-mannoside, and yeast mannan completely inhibited adherence of the bacteria to the epithelial cells. At this same concentration, D-fructose, D-lyxose, D-arabinose, and D-glyceraldehyde partially inhibited adherence. Reducing the concentration of D-mannose, or its derivatives, to between 1.0 and 0.1% resulted in partial inhibition in the adherence of the bacteria; a further reduction in the concentration to between 0.01 and 0.001% caused an enhancement of adherence up to 160% of the control level. Bacterial preincubation in 2.5% D-mannose for 1 min before epithelial cells were added completely inhibited adherence; similar treatment of the epithelial cells had no significant effect on subsequent adherence of the bacteria. Bacteria that were preincubated for 1 h with D-mannose at concentrations between 0.1 and 0.75% showed enhanced adherence. The inhibitory effect of D-mannose was decreased if bacterial adhesive ability, or cell receptivity, increased. A variety of other carbohydrates tested had no effect on the adherence of E. coli to the uroepithelial cells. These results suggest that adherence can be altered by interaction(s) between specific carbohydrate molecules and receptors on the bacterial surface.
Duck influenza lacking evidence of disease signs and immune response
Authors: Kida H , Yanagawa R , Matsuoka Y
Published: June 2021

Influenza viruses A/duck/Hokkaido/5/77 (Hav7N2), A/budgerigar/Hokkaido/1/77 (Hav4Nav1), A/Kumamoto/22/76 (H3N2), A/Aichi/2/68 (H3N2), and A/New Jersey/8/76 (Hsw1N1) were experimentally inoculated into Pekin ducks. Of these, the influenza viruses of duck and budgerigar origin replicated in the intestinal tract of the ducks. The infected ducks shed the virus in the feces to high titers, but did not show clinical signs of disease and scarcely produced detectable serum antibodies. Using immunofluorescent staining, we demonstrated that the target cells of the duck virus in ducks were the simple columnar epithelial cells which form crypts in the large intestines, especially in the colon. After primary infection, the birds resisted reinfection with the duck virus at least for 28 days, but from 46 days onward they were susceptible to reinfection. These infections were quickly restricted by a brisk secondary immune response, reflected in the rapid appearance of high titers of antibody after reinoculation. In contrat to the avian influenza viruses, the remaining three influenza viruses of human origin did not replicate in the intestinal tract but did cause a serum antibody response.
PLC/PRF/5 (Alexander) hepatoma cell line: further characterization and studies of infectivity
Authors: Daemer R J , Feinstone S M , Alexander J J , Tully J G , London W T , Wong D C , Purcell R H
Published: June 2021

The Alexander hepatoma cell line, PLC/PRF/5, was studied for evidence of hepatitis B virus markers and alpha-fetoprotein. Only hepatitis B surface antigen and alpha-fetoprotein were detected. Induction experiments with 5-iodo-2'-deoxyuridine and inoculation of chimpanzees with whole cells or tissue culture fluid did not reveal evidence of synthesis of additional hepatitis B virus markers or of production of infectious virus.
Background prevalence of microagglutination antibodies to Legionella pneumophila serogroups 1, 2, 3, and 4
Authors: Helms C M , Johnson W , Renner E D , Hierholzer W J , Wintermeyer L A , Viner J P
Published: June 2021

The background prevalence of microagglutination antibodies to Legionella pneumophila was determined by testing the sera of 517 individuals who lived or worked in a small Iowa town. In this population, the upper limit of normal microagglutination titer for serogroups 1, 3, and 4 was 1:16, and that for serogroup 2 was 1:8. The prevalence of microagglutination titers of greater than or equal to 1:32 against any serogroup of L. pneumophila was only 7.4% and did not vary significantly with age or sex.
Isolation of Binding Sites to Glycophorin from
Mycoplasma pneumoniae
Membranes
Authors: Banai M. , Razin S. , Bredt W. , Kahane I.
Published: June 2021

Sialoglycoproteins are major receptor sites for attachment of
Mycoplasma pneumoniae
to respiratory epithelium and erythrocytes (RBC). We used glycophorin, the major sialoglycoprotein of human RBC, as a ligand in affinity chromatography for the isolation of the binding sites from
M. pneumoniae
membranes. Membranes isolated from
M. pneumoniae
cells, radioiodinated by the lactoperoxidase technique, were treated with 0.5% deoxycholate. The insoluble residue, exhibiting an increased capacity to bind to RBC, was solubilized by 0.1% sodium dodecyl sulfate. The solubilized material was subjected to chromatography on a glycophorin-Sepharose column. The fraction retained on the column was eluted with 0.2% sodium dodecyl sulfate. It lacked the high-molecular-weight polypeptides and was highly enriched with two polypeptides (apparent molecular weights, 45,000 and 25,000). The eluted fraction exhibited a high capacity to bind to glycophorin-Sepharose beads and a lower capacity to bind to RBC. The binding of the eluted fraction to RBC was almost completely abolished by glycophorin, but not by its hydrophobic moiety. Binding of the fraction to glycophorin-Sepharose beads was inhibited to about the same extent by both glycophorin and its hydrophobic moiety, suggesting that components of the eluted fraction are also capable of binding to the hydrophobic moiety of glycophorin, which is apparently exposed on the beads but not on the RBC surface.
Immunochemical properties of antigen-specific monkey T-cell suppressor factor induced with a Streptococcus mutans antigen
Authors: Lamb J R , Zanders E D , Kontiainen S , Lehner T
Published: June 2021

Antigen-specific suppressor factor could be released from monkey suppressor T cells induced in vitro with a protein antigen isolated from the carcinogenic bacterium Streptococcus mutans. The suppressor activity was due to the factor itself and not to carryover of free antigen. Characterization of the monkey factor revealed it to have a molecular weight of ca. 70,000, and to contain a constant region and determinants encoded by the major histocompatibility complex. The presence of immunoglobulin determinants could not be demonstrated. However, by virtue of its adsorption to specific antigen, an antigen-combining site was shown to be present. The possible regulatory role of streptococcal antigen-specific suppressor factor in protection against dental caries is discussed.
Bacteremia associated with Haemophilus influenzae type e biotype 4
Authors: Cawthern T H , Marraro R V , McCleskey F K
Published: June 2021

Haemophilus influenzae type e biotype 4 was isolated from a single antemortem blood culture obtained from a 60-year-old, white male with abdominal carcinomatosis.
Production of human lymphoblastoid interferon by Namalva cells
Authors: Zoon K C , Buckler C E , Bridgen P J , Gurari-Rotman D
Published: June 2021

Optimum conditions for growth and interferon production by a human lymphoblastoid cell line, Namalva, have been studied. Adaptation to large-scale production is possible utilizing either Sendai virus or Newcastle disease virus. Priming of cultures before induction is unnecessary. The interferon produced has properties similar to human leukocyte interferon. The production of lymphoblastoid interferon per cell is increased two- to fourfold after dilution with serum-free medium of a saturation-density culture of Namalva induced with Newcastle disease virus. Maximum interferon yields were obtained 27 h after the addition of virus, using cultures diluted to 4 X 10(5) to 9 X 10(5) cells per ml. The presence of glutamine in the dilution medium was required for maximum interferon production. Newcastle disease virus appeared to inhibit the rates of RNA and protein synthesis more effectively in the diluted cultures.
Serotyping herpes simplex virus isolated by enzyme-linked immunosorbent assays
Authors: Mills K W , Gerlach E H , Bell J W , Farkas M E , Taylor R J
Published: June 2021

An enzyme-linked immunosorbent assay (ELISA) using a double-antibody sandwich tecnhique has been developed to serotype isolates of herpes simplex virus from clinical sources. The results obtained using this procedure were in agreement with those obtained with a standard neutralization test in typing stock cultures and 32 clinical isolates of herpes simplex virus. Clear differentiation between the two viral serotypes was obtained using rabbit immunoglobulin cross-absorbed with heterologous virus antigen. The ELISA procedure described appears to be a convenient and accurate substitute for the neutralization test in typing herpes simplex viruses. ELISA techniques require relatively small amounts of antigen and antibody and can be performed with very simple equipment.
Rapid identification of Neisseria gonorrhoeae and Neisseria meningitidis by using enzymatic profiles
Authors: D'Amato R F , Eriquez L A , Tomfohrde K M , Singerman E
Published: June 2021

The enzymatic profiles of Neisseria gonorrhoeae, N. meningitidis, and related species were determined, using a total of 48 chromogenic substrates. Enzyme classes assayed for included glycosidases, aminopeptidases, phosphoamidases, proteases, lipases, esterases, and aryl sulfatase. A final test selection of 10 substrates, based upon their differential and reproducible characteristics, allowed the separation of N. gonorrhoeae and N. meningitidis from each other and from all species tested within 4 h after primary isolation on modified Thayer-Martin medium. The need for subculturing suspect colonies from modified Thayer-Martin medium to chocolate medium with a subsequent loss of 18 to 24 h of identification is eliminated.
Immune adherence hemagglutination test applied to the study of herpes simplex and varicella-zoster virus infections
Authors: Gillani A , Spence L
Published: June 2021

The immune adherence hemagglutination (IAHA) test has been used successfully to detect antibody to herpes simplex (HS) virus and varicella-zoster (V-Z) virus. Comparative studies between the complement-fixation (CF) test and the IAHA test revealed that, in most cases, the IAHA test was more sensitive than the CF test. Furthermore, diagnosis on the basis of a fourfold change in antibody titer was made more rapidly by the IAHA test. The IAHA test was found to be a very simple and practical technique requiring only a few hours for completion compared with the conventional CF test which required up to 24 h. In addition, both sera and cerebrospinal fluids could be tested in very low dilutions in the IAHA test, so that very low levels of antibody could be detected. Also, the IAHA test detected antibody to V-Z virus more frequently than did the CF test in adults with a history of varicella occurring 9 to 30 years prior to sampling. The level of cross-reaction between HS and V-Z viruses was examined by both the CF test and the IAHA test, and no major differences between the two techniques were found.
Use of Autobac 1 for rapid assimilation testing of Candida and Torulopsis species
Authors: Ngui Yen J H , Smith J A
Published: June 2021

We devised a system of presumptive identification of some yeasts that uses the Autobac 1 (Pfizer Inc.) instrument to detect carbon assimilation by 218 strains of Candida and Torulopsis. This system compared favorably with a conventional system of yeast identification and also with the Uni-Yeast-Tek (Corning Medical) and API (Analytab Products Inc.) methods.
Radioimmunoprecipitation Assay for Quantitation of Serum Antibody to the Hemagglutinin of Type A Influenza Virus
Authors: Six Howard R. , Kasel Julius A.
Published: June 2021

A double-antibody radioimmunoprecipitation (RIP) assay has been developed to provide a sensitive and specific measure of antibody to hemagglutinins of H3N2 influenza viruses. Chloramine T was used to radiolabel purified hemagglutinins to high specific activity without loss of antigenicity. The purity of the labeled hemagglutinin was confirmed by sodium dodecyl sulfate polyacrylamide gel electrophoresis, which also established that both the HA
1
and HA
2
polypeptides were iodinated. Radiolabeled hemagglutinins with a specific activity that did not exceed 12 μCi/μg of protein could be maintained for up to 30 days at −70°C in the presence of supplemental protein. The RIP assay was compared with conventional methods, hemagglutination inhibition and viral neutralization tests, using H3N equine 1 hybrid viruses for determining serum antihemagglutinin antibody titers. The geometric mean titers for human convalescent sera after infection with A/England/72 virus were 118, 161, and 18,822 for hemagglutination inhibition, viral neutralization, and RIP tests, respectively, and the three tests demonstrated significant rises in antihemagglutinin antibody titers with equal efficiency. In general, a positive correlation existed between antihemagglutinin antibody titers determined by these three procedures; however, the antibody level determined by RIP assay for each individual could not be related to hemagglutination inhibition or viral neutralization titers by a constant factor. A similar lack of a constant relationship was found by using hyperimmune guinea pig antisera, which suggests that the RIP assay can detect antibody populations that exhibit differing efficiencies for inhibition of viral hemagglutination and replication.
In vitro stimulation of bovine peripheral blood lymphocytes: comparison of round- and flat-bottom microtiter plates for detection of tuberculin hypersensitivity
Authors: Sloane E D , Muscoplat C C , Kaneene J M , Klausner D J , Thoen C O , Johnson D W
Published: June 2021

Lymphocytes from Mycobacterium bovis-sensitized and normal cattle were cultured in round- and/or flat-bottom microtiter plates and stimulated with M. bovis purified protein derivative (PPD) tuberculin. Blastogenic responses of lymphocytes from M. bovis-sensitized cattle to PPD cultured in round-bottom plates were significantly greater than those of lymphocytes cultured in flat-bottom microtiter plates. Normal lymphocytes of nonsensitized cattle were not stimulated by PPD in either round- or flat-bottom microtiter plates. Kinetics of lymphocyte responses in round-bottom plates are presented.
Electrical impedance measurements: rapid method for detecting and monitoring microorganisms
Authors: Cady P , Dufour S W , Shaw J , Kraeger S J
Published: June 2021

A conceptually simple and east-to-use technique is described that uses continuous impedance measurements for automated monitoring of microbial growth and metabolism. The method has been applied to a wide range of microorganisms. Optical clarity is not required. The sensitivity and reproducibility of the method are demonstrated. The mechanism whereby microbial growth alters the impedance of the medium is discussed, as well as potential applications of the method to clinical microbiology.
Syncytia inhibition by immune lymphocytes: in vitro test for immunity to canine distemper
Authors: Krakowka S , Wallace A L , Koestner A
Published: June 2021

A simple and rapid (24-h) assay for peripheral blood lymphocyte-associated immunity to canine distemper virus (CDV) is described. The test is based upon leukocyte-associated inhibition of CDV-induced syncytia formation in Vero cells. The technique quantitates the response morphologically, thereby eliminating the requirement for release of radiolabeled compounds. Positive results were determined from specific-pathogen-free and gnotobiotic dogs exposed to CDV via hyperimmunization, vaccination with a modified live virus vaccine, and after virulent virus infection. Preinoculation lymphocytes and lymphocytes from non-immune dogs did not inhibit CDV-induced syncytia formation. Maximum responses were observed 7 to 21 days after initial exposure and declined thereafter. The method can be used to further investigate the role of immune lymphocytes in the recovery from CDV infection.
Evaluation of an automated agar plate streaker
Authors: Tilton R C , Ryan R W
Published: June 2021

An automated agar plate streaker was evaluated. The Autostreaker mechanizes the agar plate streaking process by providing storage for plates, labeling and streaking one or more plates for either isolation or quantitation, and stacking in one of several racks for subsequent incubation. Results showed the Autostreaker to produce agar plates with well-separated colonies and accurate colony counts. A total of 1,930 clinical specimens were processed either in parallel with manual methods or solely by the Autostreaker. Technologist acceptance of machine-streaked plates was outstanding.
Direct-Plate Serological Grouping of Beta-Hemolytic Streptococci from Primary Isolation Plates with the Phadebact Streptococcus Test
Authors: Slifkin Malcolm , Engwall Carol , Pouchet Gail R.
Published: June 2021

The grouping of beta-hemolytic streptococcal isolates by a new direct-plate procedure employing Phadebact Streptococcus Test reagents was compared with the results obtained with the 4- and 24-h Phadebact grouping procedure and with the Lancefield grouping obtained with a capillary precipitin test. The new procedure employed a modification of the Phadebact procedure that permitted the grouping of streptococci on glass slides with a minimum of five primary isolated colonies. When only five to eight colonies were available for direct testing with each Phadebact reagent, coagglutination was better manifested when the colonies were disaggregated on a glass slide in a loopful of Tween 80 solution. Further enhancement of the coagglutination reaction was effected when the respective Phadebact reagents were employed in relatively small volumes. The direct-plate procedure permitted the correct identification of 127 out of 129 betahemolytic isolates. The 4-h method correctly identified 192 of the 200 streptococci tested. All of the 200 isolates tested by the 24-h procedure and the Lancefield grouping were correctly identified. The direct-plate Phadebact procedure affords the clinical microbiologist a rapid and reliable means of identifying groups A, B, C, and G beta-hemolytic streptococci. When sufficient numbers of primary colonies are not available for the direct procedure, the 4- or 24-h procedures may be employed.
Peptocoagulase: clotting factor produced by bovine strains of Peptococcus indolicus
Authors: Switalski L M , Schwam O , Smyth C J , Wadström T
Published: June 2021

The production of a clotting factor (peptocoagulase) by bovine clinical isolates of Peptococcus indolicus and its nature were investigated. Extracellular peptocoagulase was demonstrated in culture filtrates of 93% and cell associated with washed cell suspensions of 100% of the 75 isolates tested. Both citrated and heparinized plasma were clotted. Crude peptocoagulase was nondialyzable, precipitated with (NH4)2SO4 at 40% saturation, somewhat resistant to heating at both neutral and acid pH, and chloroform insoluble. Culture filtrate did not contain proteolytic activity with albumin and casein, as substrates and no esterase activity was detected with tosylarginine and benzoylarginine methyl esters as substrates. The clotting reaction required peptocoagulase, prothrombin, and fibrinogen. The activation of prothrombin appeared to involve a stoichiometric reaction with peptocoagulase, possibly by formation of a stable complex.
Rapid Determination of
Corynebacterium diphtheriae
Toxigenicity by Counterimmunoelectrophoresis
Authors: Thompson Nancy L. , Ellner Paul D.
Published: June 2021

A method for detecting toxin production in
Corynebacterium diphtheriae
cultures by counterimmunoelectrophoresis is described. Precipitin lines were observed in toxigenic strains in 30 min.
Atypical Yersinia enterocolitica: clinical and epidemiological parameters
Authors: Bottone E J
Published: June 2021

Infections due to biochemically typical Yersinia enterocolitica usually present as gastroenteritis, mesenteric lymphadenitis, terminal ileitis, and septicemia often with visceral abscesses. In these instances, the isolates have been biochemically typical and of well-established serotypes, namely 0:3 or 0:9 and, in the United States, 0:5 or 0:8. The recovery, recognition, and significance of biochemically and serologically atypical Y. enterocolitica in human infections has proceeded more slowly. From an analysis of the clinical histories of 20 patients infected with 21 such aberrant Y. enterocolitica, it appears that these strains are of restricted pathogenic potential, producing various clinical entities such as localized skin abscesses, conjunctivitis, self-limiting enteritis, and wound and urinary tract infections in hosts with predisposing factors. Epidemiologically, whereas episodic acquisition of atypical strains by hospitalized patients is indicative of nosocomial transmission, in the present series sporadic isolations over a 4-year period, mainly from ambulatory patients, suggest an occult reservoir in the community serviced by The Mount Sinai Hospital. In contrast to typical Y. enterocolitica, which has become well adapted in animal and human hosts, it appears that environmental strains may be in the evolutionary process of becoming adapted to humans.
Supplemental Material: Slab-derived sulfate generates oxidized basaltic magmas in the southern Cascade arc (California, USA)
Authors: Muth Michelle , Wallace Paul
Published: June 2021

Tables S1–S14, Figures S1–S16, and supplemental methods.
Delirium and long term cognition in critically ill patients
Authors: Wilcox M Elizabeth , Girard Timothy D , Hough Catherine L
Published: June 2021

Delirium, a form of acute brain dysfunction, is very common in the critically ill adult patient population. Although its pathophysiology is poorly understood, multiple factors associated with delirium have been identified, many of which are coincident with critical illness. To date, no drug or non-drug treatments have been shown to improve outcomes in patients with delirium. Clinical trials have provided a limited understanding of the contributions of multiple triggers and processes of intensive care unit (ICU) acquired delirium, making identification of therapies difficult. Delirium is independently associated with poor long term outcomes, including persistent cognitive impairment. A longer duration of delirium is associated with worse long term cognition after adjustment for age, education, pre-existing cognitive function, severity of illness, and exposure to sedatives. Interestingly, differences in prevalence are seen between ICU survivor populations, with survivors of acute respiratory distress syndrome experiencing higher rates of cognitive impairment at early follow-up compared with mixed ICU survivor populations. Although cognitive performance improves over time for some ICU survivors, impairment is persistent in others. Studies have so far been unable to identify patients at higher risk of long term cognitive impairment; this is an active area of scientific investigation.
Rare diseases in healthcare priority setting: should rarity matter?
Authors: Albertsen Andreas
Published: June 2021

Rare diseases pose a particular priority setting problem. The UK gives rare diseases special priority in healthcare priority setting. Effectively, the National Health Service is willing to pay much more to gain a quality-adjusted life-year related to a very rare disease than one related to a more common condition. But should rare diseases receive priority in the allocation of scarce healthcare resources? This article develops and evaluates four arguments in favour of such a priority. These pertain to public values, luck egalitarian distributive justice the epistemic difficulties of obtaining knowledge about rare diseases and the incentives created by a higher willingness to pay. The first is at odds with our knowledge regarding popular opinion. The three other arguments may provide a reason to fund rare diseases generously. However, they are either overinclusive because they would also justify funding for many non-rare diseases or underinclusive in the sense of justifying priority for only some rare diseases. The arguments thus fail to provide a justification that tracks rareness as such.
Physician outreach during a pandemic: shared or collective responsibility?
Authors: Lanphier Elizabeth
Published: June 2021

In ‘Ethics of sharing medical knowledge with the community: is the physician responsible for medical outreach during a pandemic?’ Strous and Karni note that the revised physician’s pledge in the World Medical Association Declaration of Geneva obligates individual physicians to share medical knowledge, which they interpret to mean a requirement to share knowledge publicly and through outreach. In the context of the COVID-19 pandemic, Strous and Karni defend a form of medical paternalism insofar as the individual physician must reach out to communities who may not want, or know to seek out, medical advice, for reasons of public health and health equity. Strous and Karni offer a novel defence of why physicians ought to intervene even in insular communities, and they offer suggestions for how this could be done in culturally sensitive ways. Yet their view rests on an unfounded interpretation of the Geneva Declaration language. More problematically, their paper confuses shared and collective responsibility, misattributing the scope of individual physician obligations in potentially harmful ways. In response, this reply delineates between shared and collective responsibility, and suggests that to defend the obligation of medical outreach Strous and Karni propose, it is better conceptualised as a collective responsibility of the medical profession, rather than a shared responsibility of individual physicians. This interpretation rejects paternalism on the part of individual providers in favour of a more sensitive and collaborative practice of knowledge sharing between physicians and communities, and in the service of collective responsibility.
A comparison between agent-based and GIS-based tsunami evacuation simulations: a case study for Tofino, BC
Authors: Kim Joseph , Takabatake Tomoyuki , Nistor Ioan , Shibayama Tomoya
Published: June 2021

Soft measures such as evacuation planning are recommended to mitigate the loss of life during tsunamis. Two types of evacuation models are widely used: (i) agent-based modelling (ABM) defines sets of rules that individual agents in a simulation follow during a simulated evacuation; and (ii) geographical information systems (GIS) are more accessible to city planners, but cannot incorporate the dynamic behaviours found in ABMs. The two evacuation modelling methodologies were compared through a case study by assessing the state of evacuation preparedness and investigating potential mitigation options. The two models showed different magnitudes for mortality rates and facility demand but had similar trends. Both models agreed on the best solution to reduce the loss of life for the community. GIS may serve as a useful tool for initial investigation or as a validation tool for ABMs. ABMs are recommended for use when modelling evacuation until GIS methodologies are further developed.
Transparent boundary conditions for discretized non-Hermitian eigenvalue problems
Authors: Heinz Jonathan , Kolesik Miroslav
Published: June 2021

A method is presented for transparent, energy-dependent boundary conditions for open, non-Hermitian systems, and is illustrated on an example of Stark resonances in a single-particle quantum system. The approach provides an alternative to external complex scaling, and is applicable when asymptotic solutions can be characterized at large distances from the origin. Its main benefit consists in a drastic reduction of the dimesnionality of the underlying eigenvalue problem. Besides application to quantum mechanics, the method can be used in other contexts such as in systems involving unstable optical cavities and lossy waveguides.
A combined traffic flow forecasting model based on graph convolutional network and attention mechanism
Authors: Zhang Hong , Chen Linlong , Cao Jie , Zhang Xijun , Kan Sunan
Published: June 2021

Accurate traffic flow forecasting is a prerequisite guarantee for the realization of intelligent transportation, but due to the complex spatiotemporal characteristics of traffic flow, its forecasting has always been difficult. Deep learning can learn the deep spatiotemporal characteristics of traffic flow from a large amount of data. Deep learning can learn the deep spatiotemporal characteristics of traffic flow from a large amount of data. This paper establishes a novel combination forecasting model GGCN-SA based on deep learning for traffic flow to effectively capture the spatiotemporal characteristics of traffic flow and improve forecasting accuracy. The model captures the spatial correlation of the road traffic network through the graph convolutional network (GCN), captures the time dependence of the traffic flow through the gated recursive unit (GRU), and further introduces the soft attention mechanism (Soft Attention) to aggregate different neighborhoods Spatio-temporal information within the range to enhance the model’s ability to characterize the temporal and spatial characteristics of traffic flow. A large number of experiments have been conducted on the METR-LA and SZ-taxi data sets. The experimental results show that the GGCN-SA model proposed in this paper has better forecasting performance compared with the baseline methods.
On gapped continuum resonance spectra
Authors: Megías Eugenio , Quirós Mariano
Published: June 2021

In this work, we study a warped five-dimensional (5D) model with ultraviolet (UV) and infrared (IR) branes, that solves the hierarchy problem with a fundamental 5D Planck scale [Formula: see text], and curvature parameter [Formula: see text], of the order of the 4D Planck mass [Formula: see text] TeV. The model exhibits a continuum of Kaluza–Klein (KK) modes with different mass gaps, at the TeV scale, for all fields. We have computed Green’s functions and spectral densities, and shown how the presence of a continuum KK spectrum can produce an enhancement in the cross-section of some Standard Model processes. The metric is linear near the IR, in conformal coordinates, as in the linear dilaton (LD) and 5D clockwork models, for which [Formula: see text] TeV. We also analyze a pure (continuum) LD scenario, solving the hierarchy problem with more conventional fundamental [Formula: see text] and [Formula: see text] scales of the order of [Formula: see text], and a continuum spectrum.
Bright soliton dynamics in higher-dimensional system with power-law nonlinearity
Authors: Chen Yujie , Ren Yuan , Liu Zhengliang , Liu Tong , Wu Hao , Xiong Zhenyu , Wang Ying , Cheng Quan , Wang Ruquan
Published: June 2021

For power-law nonlinear system in higher-dimensional setting like the three-dimensional case, we derived its bright soliton solution with specific power-law feature based on the self-similar method. The dynamical evolution pattern of the derived solution is pictorially demonstrated which illustrates the typical bright soliton feature. The theoretical results presented in this work can be used to guide experimental observation of soliton behavior in higher-dimensional system with power-law nonlinearity.