bluuebunny/crossref_metadata_2025 huggingface dataset:
Transfer of Haemophilus influenzae chromosomal genes by cell-to-cell contact
Authors: Albritton W L , Setlow J K , Slaney L
Published: June 2021

A low-frequency exchange of chromosomal markers was observed in matings of Haemophilus influenzae. Transfer did not appear to be due to classical transformation or to be plasmid mediated, and chromosomal gene transfer differed in several respects from plasmid transfer by conjugation.
Bioenergetic properties and viability of alkalophilic Bacillus firmus RAB as a function of pH and Na+ contents of the incubation medium
Authors: Kitada M , Guffanti A A , Krulwich T A
Published: June 2021

The bioenergetic properties and viability of obligately alkalophilic Bacillus firmus RAB have been examined upon incubation in alkaline and neutral buffers in the presence or absence of added Na+. At pH 10.5, cells incubated in the absence of Na+ exhibited an immediate rise in cytoplasmic pH from less than 9.5 to 10.5, and they lost viability very rapidly. Viability experiments in the presence or absence of an energy source further suggested that the Na+-dependent mechanism for pH homeostasis is an energy-requiring function. The Na+/H+ antiporter, which catalyzes the vital proton accumulation at alkaline pH, was only slightly operational at pH 7.0; both whole cells and vesicles exhibited net proton extrusion even in the presence of Na+. Moreover, cells incubated in buffer at pH 7.0 were actually more viable in the presence of Na+ than in its absence. Thus, the inability of B. firmus RAB to grow at neutral pH is not due to excessive acidification of the cytoplasm. Rather, the transmembrane electrical potential, delta psi, generated at pH 7.0 was found to be much lower than at alkaline pH. The very low delta psi compromised several cell functions, e.g., Na+/solute symport and motility, which in this and other alkalophiles specifically depend upon delta psi and Na+.
Enzymatic activities for interconversion of purines in spirochetes
Authors: Canale-Parola E , Kidder G W
Published: June 2021

Enzymatic activities that catalyze the interconversion of purines and purine derivatives were detected in cell extracts of Spirochaeta aurantia, Spirochaeta stenostrepta, Treponema succinifaciens, and Treponema denticola. Phosphoribosyltransferase activities present in cell extracts of each of the four spirochete species functioned in the conversion of adenine, hypoxanthine, and guanine to AMP, IMP, and GMP, respectively. Nucleotidase activities in the extracts mediated the formation of nucleosides from nucleotides. The conversion of adenosine, inosine, and guanosine to the respective purine bases was catalyzed by nucleoside phosphorylase and, in some instances, by nucleoside hydrolase activities. Guanine deaminase activity was found in both S. aurantia and S. stenostrepta, whereas adenosine deaminase activity was detected only in S. aurantia. Adenine deaminase activity in T. succinifaciens extracts was sensitive to O2 and was relatively resistant to heating. Our results indicate that the four species of spirochetes studied possess a broad spectrum of purine interconversion enzymes. It is suggested that these enzymes may function in metabolic processes important for the survival of spirochetes in nutrient-poor natural environments.
Identification of two genes immediately downstream from the polA gene of Escherichia coli
Authors: Joyce C M , Grindley N D
Published: June 2021

We have identified two genes within a 1-kilobase region immediately following the polA gene of Escherichia coli. The first, whose transcription is initiated about 150 base pairs beyond the end of the polA coding sequence, is the gene corresponding to the previously sequenced "spot 42 RNA" (B. G. Sahagan and J. E. Dahlberg, J. Mol. Biol. 131:573--592, 1979). The second, located further downstream and transcribed towards polA, is the structural gene for a 22-kilodalton polypeptide, which we have detected by using plasmid-directed protein synthesis in maxicells. Sequence analysis of this region of the E. coli genome suggests that it contains little, if any, redundant DNA.
Cosegregation of cell wall and DNA in Bacillus subtilis
Authors: Schlaeppi J M , Karamata D
Published: June 2021

Cosegregation of cell wall and DNA of a lysis-negative mutant of Bacillus subtilis was examined by continuously labeling (i) cell wall, (ii) DNA, and (iii) both cell wall and DNA. After four to five generations of chase in liquid media it was found by light microscope autoradiography that the numbers of wall segregation units per cell are 29 and 9 in rich and minimal medium, respectively. Under the same conditions the numbers of segregation units of DNA were almost 50% lower: 15 and 5, respectively. Simultaneous labeling of cell wall and DNA (iii) provided figures almost identical to those obtained for cell wall alone, (i), implying cosegregation of the two components. Statistical analysis ruled out their random distribution into daughter cells. Measurements of the positions of grain clusters at the end of the chase period along chains of cells, each derived from a single cell at the beginning of chase, show that cell wall units are localized according to a symmetrical pattern, whereas those of DNA are distributed in an asymmetrical but highly regular way. It appears that of two cell wall units of the same age one only has a strand of DNA attached to it. We present a simple diagrammatic model of cell wall organization and DNA-cell wall association which is compatible with our observations. Finally, we discuss previous experiments pertinent to cosegregation of cell wall and DNA obtained with cells grown on solid media as well as with germinating spores; an explanation for the independent segregation of cell wall and DNA observed in the latter case is advanced.
Characterization of ATP citrate lyase from Chlorobium limicola
Authors: Antranikian G , Herzberg C , Gottschalk G
Published: June 2021

ATP citrate lyase (EC 4.1.3.8) from Chlorobium limicola was partially purified. It was established that the consumption of substrates and the formation of products proceeded stoichiometrically and that citrate cleavage was of the si-type. ADP and oxaloacetate inhibited enzyme activity. Oxaloacetate also inhibited the growth of C. limicola.
Facilitated diffusion of 6-deoxy-D-glucose in bakers' yeast: evidence against phosphorylation-associated transport of glucose
Authors: Romano A H
Published: June 2021

6-Deoxy-D-glucose, a structural homomorph of D-glucose which lacks a hydroxyl group at carbon 6 and thus cannot be phosphorylated, is transported by Saccharomyces cerevisiae via a facilitated diffusion system with affinity equivalent to that shown with D-glucose. This finding supports the facilitated diffusion mechanism for glucose transport and contradicts theories of transport-associated phosphorylation which hold that sugar phosphorylation is necessary for high-affinity operation of the glucose carrier.
Usefulness of serial antibody determinations in diagnosis of candidiasis as measured by discontinuous counterimmunoelectrophoresis using HS antigen
Authors: Marier R , Andriole V T
Published: June 2021

We have followed the candida antibody response in 115 patients with different types of candidiasis by discontinuous counterimmunoelectrophoresis using HS antigen to learn whether any early antibody response occurs in systemic candidiasis and whether there are differences in the antibody response in candidiasis involving different organ systems. We found that 23 of 32 (72%) patients with systemic candidiasis had a rise in antibody titer within the first 2 weeks of infection and that high titers were relatively insensitive indicators of infection. No differences were seen in the antibody response in different types of candidiasis. Patients with aspergillosis and torulopsosis had titer rises as well which were attributed to either inapparent candida infection or cross-reacting antibody. A rise in titer was not seen in any patient with candida colonization, bacterial or viral infection, or no infection in contrast to titers greater than or equal to 1/1 or greater than or equal to 1/8 which were seen in these conditions.
Discrepancy between results of the Streptozyme test and those of the antideoxyribonulcease B and antihyaluronidase tests
Authors: Hederstedt B , Holm S E , Wadstrom T
Published: June 2021

Comparison of the serum titers obtained with the Streptozyme, the antistreptolysin O, the antideoxyribonuclease B, and the antistreptohyaluronidase tests suggested that the Streptozyme test had failed to detect antibodies against streptococcal deoxyribonuclease B and hyaluronidase. Moreover, sera that were negative in the Streptozyme test could be shown by immunodiffusion to possess significant numbers of precipitins against extracellular factors produced by group A streptococci. Follow-up studies on patients with diagnosed streptococcal infections revealed elevated antideoxyribonuclease and streptohyaluronidase titers and increased numbers of precipitation lines without simultaneous increased titers by the Streptozyme test. There is thus a need for stricter control of possible batch-to-batch variations and more careful standardization of the antigen content of the Streptozyme test.
Identification of Achromobacter species by cellular fatty acids and by production of keto acids
Authors: Dees S B , Moss C W
Published: June 2021

The cellular fatty acid composition and metabolic products of 12 reference strains of Achromobacter sp. and A. xylosoxidans were determined by gas-liquid chromatography (GLC). Results showed that the two Achromobacter groups are strikingly different and can be readily distinguished on the basis of cellular fatty acids and the short-chain acids produced by Achromobacter sp. The major cellular fatty acids of Achromobacter sp. were octadecenoic (18:1) and a 19-carbon cyclopropanoic (19:0 delta) acid, whereas hexadecanoic (16:0) and a 17-carbon cyclopropanoic (17:0 delta) acid were principal components of the lipids of A. xylosoxidans. Hydroxy acids were not found in strains of Achromobacter sp. but comprised approximately 20% of the cellular fatty acids of A. xylosoxidans. In addition, Achromobacter sp. produced relatively large amounts of 2-ketoisocaproic acid, which was detected in only trace amounts from strains of A. xylosoxidans. The data show that GLC tests provide additional criteria for differentiating groups which are very closely related when evaluated with conventional tests. The GLC tests can be readily adapted in the clinical laboratory because they are rapid, highly reproducible, relatively inexpensive, and simple to perform.
Counterimmunoelectrophoresis of Reiter Treponeme Axial filaments as a diagnostic test for syphilis
Authors: Nell E E , Hardy P H
Published: June 2021

Purified axial filaments from the cultivable Reiter treponeme, previously shown to share an antigenic component with pathogenic Treponemia pallidum, were evaluated as antigen in a diagnostic test for syphilis. Antibody to the filaments was revealed by counterimmunoelectrophoresis. Conditions that produced optimal results in the test were established. A total of 343 sera from normal individuals, biological false-positive reactors, and from patients in the different stages of syphilis were subjected to the test. The results indicate the test to be sensitive and highly specific for detecting treponemal antibodies in human syphilis.
Mycoplasmas in human pyelonephritis: demonstration of antibodies in serum and urine
Authors: Thomsen A C
Published: June 2021

This study was carried out to elucidate by serological examination the etiological significance of mycoplasmas isolated from the upper urinary tract of patients with pyelonephritis. The occurrence of antibodies in patients with acute pyelonephritis, chronic pyelonephritis with or without exacerbation, or noninfectious urinary tract disease was compared by the indirect hemagglutination method. Antibody response was demonstrated significantly more often in patients yielding growth of Mycoplasma hominis from the upper urinary tract than in patients not yielding growth. Antibodies against M. hominis were demonstrated in ureteric and bladder urine from three patients with acute pyelonephritis and from one patient with exacerbation of chronic pyelonephritis. M. hominis was isolated from the upper urinary tract of all four patients. Urine antibodies could not be demonstrated in any other cases. Thus, it seems highly possible that M. hominis may play a role in pyelonephritis of humans. The investigations did not disclose a similar role for Ureaplasma urealyticum.
Immune reactions in human filariasis
Authors: Subrahmanyam D , Mehta K , Nelson D S , Rao Y V , Rao C K
Published: June 2021

Sera from cases of elephantiasis due to Wuchereria bancrofti infection promoted an intense adhesion of peripheral blood leukocytes to W. bancrofti microfilariae in vitro. A similar adhesion was also seen using sera from some normal persons living for several years in areas where filariasis is endemic. No such adhesion was evident with sera from microfilaria carriers or from normal subjects from nonendemic areas. The adhesion was complement independent and was associated with the immunoglobulin G fraction of serum. 51Cr release studies suggested the occurrence of cell-mediated cytotoxicity to W. bancrofti microfilariae in the presence of elephantiasis serum. Microfilariae of Litomosoides carinii could be isolated free of blood cells, from the blood of infected rats. In the presence of serum, or its immunoglobulin G fraction, from patients with elephantiasis, L. carinii microfilariae adhered to human peripheral blood leukocytes or rat spleen cells.
Comparison of an enzyme-linked immunosorbent assay for quantitation of rotavirus antibodies with complement fixation in an epidemiological survey
Authors: Ghose L H , Schnagl R D , Holmes I H
Published: June 2021

The development of a micro-scale enzyme-linked immunosorbent assay (ELISA) with horseradish peroxidase as the marker enzyme for the detection and measurement of human rotavirus antibodies is described. A semipurified preparation of the serologically related simian agent, SA-11 virus, was used as the antigen. Test sera were reacted with antigen-sensitized wells in disposable poly-vinyl microplates. Any attached antibody was detected by the addition of peroxidase-labeled anti-species immunoglobulin (conjugate) followed by assay of the enzyme reaction with its substrate, hydrogen peroxide plus 5-aminosalicylic acid. This micro-ELISA was compared with complement fixation in a seroepidemiological study of the age prevalence of rotavirus antibody in Aboriginal and European populations living in the same outback area in Australia. The ELISA (results read with the naked eye) proved to be approximately 16 times more sensitive than complement fixation. Of Aborigines, 71% had rotavirus complement-fixing antibody, as compared to 45% of Europeans. By ELISA 100% of both populations had rotavirus antibodies. Mean antibody titers in the different age groups were higher in Aborigines than in Europeans. Antibody levels rose steeply throughout the first 20 years of life, remained high during the next 20 years, then increased again at least up to the age of 60 years. The micro-ELISA was practical, simple to perform, and more suitable than complement fixation for large seroepidemiological rotavirus studies. It also has potential for serodiagnosis of the disease, both in the laboratory and in the field.
Solid-phase enzyme-linked immunosorbent assay for detection of hepatitis A virus
Authors: Locarnini S A , Garland S M , Lehmann N I , Pringle R C , Gust I D
Published: June 2021

An enzyme-linked immunosorbent assay (ELISA) was developed for the detection of hepatitis A virus in human fecal specimens. Investigations with 88 fecal specimens from 77 patients with suspected viral hepatitis and 8 of their household contacts showed that ELISA was as specific and sensitive as radioimmunoassay and almost as sensitive as immune electron microscopy. The ELISA is quick and simple to perform, does not require sophisticated technical equipment, and can be read with the naked eye, making it suitable for field work and rapid diagnosis.
Dental care and spread of hepatitis B virus infection
Authors: Tzukert A , Sandler S G
Published: June 2021

Sera from 576 healthy adults were tested for the hepatitis B surface antigen (HBsAg) and antibody (anti-HBs) to evaluate the role of routine dental care as a factor in the spread of hepatitis B virus (HBV) infection. Serological evidence of prior HBV infection, manifested by acquisition of anti-HBs, was detected in 97 (16.8%) individuals, and 6 (1.0%) were identified to be asymptomatic HBsAg carriers. The anticipated correlations of HBsAg and anti-HBs with age, country of birth, and socioeconomic status were observed in the study population. However, prevalences of both HBsAg and anti-HBs were inversely related to the lifetime total of dental care visits. These findings indicated that, in a region in which the HBsAg carrier state and hepatitis B are prevalent, routine dental care is not identified as an important factor in the spread of HBV infection. While the results do not exclude the obvious possibility that cross-infections with HBV may occur during dental care in specific situations, they indicate that this mode of infection is exceptional.
Neutralization of human serum lysozyme by sodium polyanethol sulfonate but not by sodium amylosulfate
Authors: Traub W H , Fukushima P I
Published: June 2021

Sodium polyanethol sulfonate (SPS) at 500 microgram/ml, but not sodium amylosulfate (SAS) at 500 microgram/ml, precipitated egg white lysozyme (1 mg and 50 microgram of lysozyme per ml) as determined with the assay strain Micrococcus lysodeikticus ATCC 4698. Fresh and heat-inactivated (56 degrees C, 30 min) human serum (80%, vol/vol) killed M. lysodeikticus (10(4) bacteria per ml at zero time) within 1 to 2 h after exposure. Addition of 250 to 500 microgram of SPS per ml to fresh human serum protected M. lysodeikticus for 22 h as effectively as absorption of either fresh or heat-inactivated human serum with bentonite (10 mg/ml of serum, 10 min, 37 degrees C); the latter procedure is known to remove serum lysozyme. In contrast, SAS at 250 and 500 microgram/ml of serum retarded killing of the assay bacteria for periods of 4 h; after overnight (22 h) incubation, however, the number of M. lysodeikticus survivors had decreased significantly. The finding that SPS, but not SAS, at 250 to 500 microgram/ml effectively neutralized serum lysozyme-mediated killing of a lysozyme-sensitive assay strain may be of relevance with respect to laboratory processing of human blood culture specimens.
Mass spectral measurement of residual oxygen in the atmosphere of an anaerobic culture chamber
Authors: Tabaqchali S , Peach S , Snedden W
Published: June 2021

A simple and reproducible procedure has been devised for sampling gases and for analysis of the residual oxygen in the atmosphere of the anaerobic culture chamber by mass spectrometer.
Capillary precipitin typing of Streptococcus pneumoniae
Authors: Russell H , Facklam R R , Padula J F , Cooksey R
Published: June 2021

The Neufeld test is presently the method of choice for typing Streptococcus pneumoniae. Although the test is reliable and relatively easy to perform, a simpler test, not requiring microscopic examination, would facilitate large-scale testing. A capillary precipitine test has been designed and tested for its usefulness in typing pneumococci. The type-specific carbohydrate antigens were obtained from broth culture supernatants. The antigens were reacted with type-specific antisera in glass capillary pipettes. Results from 82 reference antigens and 166 antigens from diagnostic pneumococcal strains showed that the reactions ere specific, and the results agreed with Neufeld test results. These results indicate that the precipitin test is as specific as the Neufeld test. The test is easy to perform, requires small amounts of antiserum, and can be completed in a short period of time.
Comparison of sensitivity and specificity of purified lymphocyte and whole-blood in vitro lymphocyte stimulation assays in detection of Brucella abortus infection in cattle
Authors: Kaneene J M , Johnson D W , Anderson R K , Muscoplat C C
Published: June 2021

A study was conducted to compare the sensitivity and specificity of purified lymphocyte and whole-blood in vitro lymphocyte stimulation assays in detection of Brucella abortus infection in cattle. Cattle used were infected with B. abortus field strains or strain 19. Peripheral blood was collected, and lymphocytes for the technique. The blood for the whole-blood lymphocyte stimulation assay was diluted 10-fold with RPMI 1640 medium (without additional serum supplement) and cultured. The two tests were run simultaneously, and B. abortus soluble antigen or concanavalin A was added to the cultures. The cultures were incubated for 6 days and assayed for [3H] thymidine incorporation into their DNA. Generally, cultures of the purified lymphocyte stimulation assay had higher counts per minute than those of the whole-blood lymphocyte stimulation assay, but the stimulation ratios for the two tests were comparable. The two assays were comparable in terms of their sensitivity and specificity as applied to detection of brucella infection in cattle.
Laboratory identification and epidemiology of streptococcal hospital isolates
Authors: Hardy M A , Dalton H P , Allison M J
Published: June 2021

A total of 343 streptococcal strains were identified to species on the basis of the progressive method of bacterial identification as advocated by Cowan & Steel's Manual for the Identification of Medical Bacteria. Comparative studies were also performed with these strains to determine the accuracy and feasibility of using various types of blood, differential media, and biochemical tests in conjunction with the progressive method of identification. The streptococcal species were then correlated with the type of specimen, sex, and age of hospitalized patients to obtain some insight into the epidemiology of hospital streptococcal isolates.
Combined methenamine-silver nitrate and hematoxylin & eosin stain for fungi in tissues
Authors: Huppert M , Oliver D J , Sun S H
Published: June 2021

Initial examination of hematoxylin & eosin-stained tissue from a human brain specimen did not reveal the fungi which were seen in subsequent tissue sections stained with methenamine-silver nitrate. Microabscesses seen in the hematoxylin & eosin-stained sections were not apparent in the methenamine--silver nitrate-stained tissue. Staining with methenamine--silver nitrate and counterstaining with hematoxylin & eosin proved excellent not only for detecting fungus cells, but also for revealing their relationship to the host cellular response in this case and in examples of experimental murine coccidioidomycosis and histoplasmosis.
Meningitis Caused by
Neisseria meningitidis
Serogroup 135
Authors: Kleiman Martin B. , Reynolds Janet , Steinfeld Jeanne , Allen Stephen D. , Smith James W.
Published: June 2021

The first descriptions of meningitis in childhood caused by
Neisseria meningitidis
serogroup 135 are presented. Difficulties with identification of unusual serogroups of
N. meningitidis
are discussed.
Bacteriology of human and animal bite wounds
Authors: Goldstein E J , Citron D M , Wield B , Blachman U , Sutter V L , Miller T A , Finegold S M
Published: June 2021

Seventy-three patients with bite wounds (16 patients with clenched-fist injuries, 18 with human bite wounds, and 39 with animal bites) were cultured aerobically and anaerobically. A total of 33 of 34 patients with human bites and clenched-fist injuries and 33 of 39 patients with animal bites had aerobic or facultative bacteria isolated from their wounds. A total of 224 strains of aerobic or facultative bacteria were isolated, the most frequent isolate being alpha-hemolytic streptococci (50 strains). Staphylococcus aureus was isolated from 18 wounds. Penicillin-resistant gram-negative rods were infrequently isolated (12 strains). Anaerobic bacteria were isolated in 18 of 34 human bite wounds and clenched-fist injuries and 16 of 39 animal bite wounds. A total of 88 anaerobic strains was isolated, the most common being various Bacteroides species (36 strains).
Enzyme-linked immunospecific antibody test for detecting antibody to Klebsiella
Authors: Rissing J P , Buxton T B , Moore W L , Ozawa T , Moore W L
Published: June 2021

The enzyme-linked immunospecific antibody test was performed in standard test tubes and microtiter plates to meausre high-titer antibody against Klebsiella capsular polysaccharide. Initial studies were conducted with rabbit sera; other studies were conducted with the serum of a patient infected with type 9 Klebsiella. Both immunized rabbits and an infected patient disclosed high titers of anticapsular antibody. Control sera from other immunized rabbits and other infected humans failed to show this substantial antibody titer against type 9 Klebsiella. Comparisons between counterimmunoelectrophoresis and indirect immunofluorescence disclosed that the sensitivity of the enzyme-linked immunospecific antibody test for anti-Klebsiella antibody ranged between 400 and 10,000 times that of these tests.
Neisseria sicca endocarditis: report of a case and review of the literature
Authors: Gay R M , Sevier R E
Published: June 2021

A rare case of bacterial endocarditis caused by Neisseria sicca is reported. Review of the literature revealed only five other cases where sufficient data existed to confirm this particular organism as the etiological agent of bacterial endocarditis.
Three variants of Corynebacterium diphtheriae subsp. mitis (Belfanti) isolated from a throat specimen
Authors: Chang D N , Laughren G S , Chalvardjian N E
Published: June 2021

Three variants of a Corynebacterium diphtheriae subsp. mitis strain belfanti, two toxigenic (phage types 7 and 11) and one nontoxigenic (phage type 7), were simultaneously isolated from the throat of an adult.
An Evaluation of Web-Based Case Studies in Microscopy
Authors: MERKEL SUSAN M. , DISPENSA MARILYN , GHIORSE WILLIAM C.
Published: June 2021

It is often difficult to provide students in introductory science courses with opportunities that mimic the investigative learning experience of doing research. This is particularly true in microbiology courses where advanced microscopy techniques are expensive and difficult to do. To that end, we developed three computer-based case studies around real-life scenarios. Our goals were to: (i) improve students’ understanding of advanced microscopic techniques, (ii) give students practice analyzing and interpreting data, and (iii) model a scientific approach to how these techniques are applied to current issues in microbiology. Each case requires students to use references and interpret actual microscopic images, thus giving them a more realistic experience than we could previously provide. We analyzed student learning and perceptions to these case studies. After doing the case studies, students were more able to apply microscopic methods to a realistic problem, thus demonstrating an understanding of how the methods are used. Students appreciated the intellectual challenges presented by having to interpret and analyze actual microscopic images. This approach has allowed us to introduce new areas of content to our course and to stimulate critical thinking skills, a difficult task in a large introductory microbiology course.
Evaluating the Impact of a Classroom Response System in a Microbiology Course
Authors: SUCHMAN ERICA , UCHIYAMA KAY , SMITH RALPH , BENDER KIM
Published: June 2021

The use of a Classroom Response System (CRS) was evaluated in two sections, A and B, of a large lecture microbiology course. In Section B the instructor used the CRS technology at the beginning of the class period posing a question on content from the previous class. Students could earn extra credit if they answered the question correctly. In Section A, the class also began with an extra credit CRS question. However, CRS questions were integrated into the lecture during the entire class period. We compared the two classes to see if augmenting lectures with this technology increased student learning, confidence, attendance, and the instructor’s ability to respond to student’s misconceptions, over simply using the CRS as a quizzing tool. Student performance was compared using shared examination questions. The questions were categorized by how the content had been presented in class. All questions came from instructors’ common lecture content, some without CRS use, and some questions where Instructor A used both lecture and CRS questions. Although Section A students scored significantly better on both types of examination questions, there was no demonstrable difference in learning based on CRS question participation. However, student survey data showed that students in Section A expressed higher confidence levels in their learning and knowledge and indicated that they interacted more with other students than did the students in Section B. In addition, Instructor A recorded more modifications to lecture content and recorded more student interaction in the course than did Instructor B.
Draft Genome Sequences of 19 Clinical
stx
-Harboring Escherichia coli O80:H2 Strains
Authors: Stevens Marc J. A. , Cernela Nicole , Müller Andrea , Nüesch-Inderbinen Magdalena , Stephan Roger
Published: June 2021

Shiga toxin-producing
Escherichia coli
(STEC) O80:H2 is an uncommon hybrid pathotype that has emerged in Switzerland and France. Here, we report the draft genome sequences of 19
stx
-harboring
Escherichia coli
O80:H2 strains isolated between 2003 and 2019 from patients in Switzerland.
Complete Genome Sequence of Sinorhizobium meliloti S35m, a Salt-Tolerant Isolate from Alfalfa Rhizosphere in Soil Native to the Caucasus Region
Authors: Muntyan Victoria S. , Afonin Alexey M. , Vladimirova Maria E. , Saksaganskaya Alla S. , Gribchenko Emma S. , Baturina Olga , Roumiantseva Marina L.
Published: June 2021

The genome of a symbiotically effective salt-tolerant strain,
Sinorhizobium meliloti
S35m, isolated from alfalfa rhizosphere in soil native to the Caucasian region, was sequenced. Genomic islands, prophages, and elements of a potential CRISPR/Cas I type (Cas3_0_I) system were identified in the genome.
Supplemental Material: Forced subduction initiation within the Neotethys: An example from the mid-Cretaceous Wuntho-Popa arc in Myanmar
Authors: Zhang Liyun , al. et
Published: June 2021

Age information on ophiolites and arcs from Myanmar and Andaman, geochronological and geochemical data for the mid-Cretaceous Mawgyi Volcanics in the Wuntho-Popa arc of central Myanmar, and published ages associated with the Neotethyan ophiolites and island arcs, with which the reader can replicate our analyses.
The Role of Stress-Induced Changes of Homer1 Expression in Stress Susceptibility
Authors: Reshetnikov Vasiliy V. , Bondar Natalia P.
Published: June 2021

Stress negatively affects processes of synaptic plasticity and is a major risk factor of various psychopathologies such as depression and anxiety. HOMER1 is an important component of the postsynaptic density: constitutively expressed long isoforms HOMER1b and HOMER1c bind to group I metabotropic glutamate receptors MGLUR1 (GRM1) and MGLUR5 and to other effector proteins, thereby forming a postsynaptic protein scaffold. Activation of the GLUR1–HOMER1b,c and/or GLUR5–HOMER1b,c complex regulates activity of the NMDA and AMPA receptors and Ca2+ homeostasis, thus modulating various types of synaptic plasticity. Dominant negative transcript Homer1a is formed as a result of activity-induced alternative termination of transcription. Expression of this truncated isoform in response to neuronal activation impairs interactions of HOMER1b,c with adaptor proteins, triggers ligand-independent signal transduction through MGLUR1 and/or MGLUR5, leads to suppression of the AMPA- and NMDA-mediated signal transmission, and thereby launches remodeling of the postsynaptic protein scaffold and inhibits long-term potentiation. The studies on animal models confirm that the HOMER1a-dependent remodeling most likely plays an important part in the stress susceptibility, whereas HOMER1a itself can be regarded as a neuroprotector. In this review article, we consider the effects of different stressors in various animal models on HOMER1 expression as well as impact of different HOMER1 variants on human behavior as well as structural and functional characteristics of the brain.
Erratum to: Dynamics and the emergence of geometry in an information mesh
Authors: Tee Philip
Published: June 2021

The original article contained a misprint.
Analysis of the attention to COVID-19 epidemic based on visibility graph network
Authors: Feng Qingxiang , Wei Haipeng , Hu Jun , Xu Wenzhe , Li Fan , Lv Panpan , Wu Peng
Published: June 2021

Most of the existing researches on public health events focus on the number and duration of events in a year or month, which are carried out by regression equation. COVID-19 epidemic, which was discovered in Wuhan, Hubei Province, quickly spread to the whole country, and then appeared as a global public health event. During the epidemic period, Chinese netizens inquired about the dynamics of COVID-19 epidemic through Baidu search platform, and learned about relevant epidemic prevention information. These groups’ search behavior data not only reflect people’s attention to COVID-19 epidemic, but also contain the stage characteristics and evolution trend of COVID-19 epidemic. Therefore, the time, space and attribute laws of propagation of COVID-19 epidemic can be discovered by deeply mining more information in the time series data of search behavior. In this study, it is found that transforming time series data into visibility network through the principle of visibility algorithm can dig more hidden information in time series data, which may help us fully understand the attention to COVID-19 epidemic in Chinese provinces and cities, and evaluate the deficiencies of early warning and prevention of major epidemics. What’s more, it will improve the ability to cope with public health crisis and social decision-making level.
A Cultural and Functional Approach to the Assessment of Logical Thinking Ability in English Writing
Authors: Juan Cao
Published: June 2021

The analysis of influencing factors of logical thinking ability in English writing is the key effective factor of evaluating logical thinking ability in English writing. In order to accurately evaluate logical thinking ability in English writing, this paper studies the evaluation method of logical thinking ability in English writing from the perspective of culture and function. This paper analyzes the relationship between the influencing factors of logical thinking ability in English writing. The factors of text structure and language expression reflect the culture and function of logical thinking ability in English writing, respectively, which have a direct impact on logical thinking ability in English writing. From these two aspects, 15 evaluation indexes are selected to construct the evaluation system of logical thinking ability in English writing. Considering the significant fuzziness of logical thinking ability in English writing from the perspective of culture and function, the comprehensive evaluation method of fuzzy mathematics is used for the process, the evaluation criteria are determined, the evaluation matrix is constructed, and the membership function is calculated, to complete the comprehensive evaluation of fuzzy mathematics based on the membership function and weight matrix. The experimental results show that this method can accurately evaluate the logical thinking ability of English writing and can be effectively used in the area of research.
The Source of Semiprimeness of Semigroups
Authors: Albayrak Barış , Yeşil Didem , Karalarlioğlu Camci Didem
Published: June 2021

In this study, we define new semigroup structures using the set

S

S

=

a
∈
S

|

a
S
a
=
0

which is called the source of semiprimeness for a semigroup

S

with zero element.

S

S

−

idempotent semigroup,

S

S

−

regular semigroup,

S

S

−

reduced semigroup, and

S

S

−

nonzero divisor semigroup which are generalizations of idempotent, regular, reduced, and nonzero divisor semigroups in semigroup theory are investigated, and their basic properties are determined. In addition, we adapt some well-known results in semigroup theory to these new semigroups.
Juvenile Systemic Lupus Erythematosus Presenting with Esophagitis and Severe Oral Mucositis
Authors: Schildt Emily , Sessions Kristen L , De Ranieri Deirdre
Published: June 2021

We present a case of a previously healthy adolescent female who developed severe oral mucositis and acute esophagitis as her presenting symptoms of juvenile systemic lupus erythematosus. Mucositis involving the lips is infrequently reported in systemic lupus erythematosus, and to our knowledge, this is the first reported case of acute, non-infectious esophagitis as a presenting symptom in a pediatric systemic lupus erythematosus patient.
Monte Carlo Sampling Method for a Class of Box-Constrained Stochastic Variational Inequality Problems
Authors: Li Pei-Yu
Published: June 2021

This paper uses a merit function derived from the Fishcher–Burmeister function and formulates box-constrained stochastic variational inequality problems as an optimization problem that minimizes this merit function. A sufficient condition for the existence of a solution to the optimization problem is suggested. Finally, this paper proposes a Monte Carlo sampling method for solving the problem. Under some moderate conditions, comprehensive convergence analysis is included as well.
Nondestructive Approach for Complex-Shaped Cracks in Concrete Structures by Electromagnetic Waves with FDTD Technique
Authors: Sener Ummu S. , Eker Sebahattin
Published: June 2021

Concrete cracks have no specific shape and do not show linearity. Since the natural occurrences of concrete cracks make simulation identification difficult, rectangular step function and a dynamic geometry are used to define a concrete surface crack in the natural process. A novel interior crack expression is obtained by accepting the area between two curves as a crack filled by air in concrete and modeling this area like a Riemann integral domain. Taking the partition of this integral domain, the most realistic definition of the crack is made. Electromagnetic (EM) waves are utilized for numerical simulation after identifying the defects, cracks, rebars, and geometry of concrete. Three different simulation setups with complex geometries with two different surface cracks and one internal crack are simulated using a finite-difference time-domain (FDTD) method with Gaussian pulse wave excitation. Simulations are obtained using both transverse electric (TEz) waves and transverse magnetic (TMz) waves and the results are compared with each other. Air-dried concrete specimens are molded following simulation setups with surface cracks and measurements are made nondestructively with a Vivaldi antenna array in the frequency range of 0.4–4.0 GHz. The reflection and transmission coefficients are validated by comparing the data obtained using the measurement with the results obtained from numerical simulation.
Clinical Characteristics and Early Interventional Responses in Patients with Severe COVID-19 Pneumonia
Authors: He Susu , Fang Lina , Xia Lingzhen , Lin Shuangxiang , Ye Junhui , Luo Dinghai
Published: June 2021

Progressive acute respiratory distress syndrome (ARDS) is the most lethal cause in patients with severe COVID-19 pneumonia due to uncontrolled inflammatory reaction, for which we found that early intervention of combined treatment with methylprednisolone and human immunoglobulin is a highly effective therapy to improve the prognosis of COVID-19-induced pneumonia patients. Objective. Herein, we have demonstrated the clinical manifestations, laboratory, and radiological characteristics of patients with severe Coronavirus Disease-2019 (COVID-19) pneumonia, as well as measures to ensure early diagnosis and intervention for improving clinical outcomes of COVID-19 patients. Summary Background Data. The COVID-19 is a new infection caused by a severe acute respiratory syndrome- (SARS-) like coronavirus that emerged in China in December 2019 and has claimed millions of lives. Methods. We included 37 severe COVID-19 pneumonia patients who were hospitalized at Taizhou Public Health Medical Center in Zhejiang province from January 17, 2020, to February 18, 2020. Demographic, clinical, and laboratory features; imaging characteristics; treatment history; and clinical outcomes of all patients were collected from electronic medical records. Results. The patients’ mean age was 54 years (interquartile range, 43−64), with a slightly higher male preponderance (57%). The most common clinical features of COVID-19 pneumonia were fever (29 (78%)), dry cough (28 (76%)), dyspnea (9 (24%)), and fatigue (9 (24%)). Serum interleukin (IL)-6 and IL-10 were elevated in 35 (95%) and 19 (51%) patients, respectively. Chest computerized tomography scan revealed bilateral pneumonia in 35 (95%) patients. Early intervention with a combination of methylprednisolone and human immunoglobulin was highly effective in improving the prognosis of these patients. Conclusions. Progressive acute respiratory distress syndrome is the most common cause of death in patients with severe COVID-19 pneumonia owing to an uncontrolled inflammatory response. Early intervention with methylprednisolone and human immunoglobulin was highly effective in improving their prognosis.
Exploring Stakeholder Perceptions of Quality Early Childhood Education in Private Day Care Centers in Ghana: A Qualitative Approach
Authors: Bamezor Belinda Lebene Ami , Quaicoe Theophilus , Forkuor John Boulard , Azumah Francess Dufie
Published: June 2021

In Ghana, despite increasing enrolment, majority of children do not have access to quality early childhood education. The lack of a context-specific and culturally relevant definition of quality in early childhood education is one of the challenges stakeholders face in promoting quality standards in Ghana. In this paper, we use data collected through qualitative semistructured interviews to explore stakeholder definition of quality in early childhood education, the implications of quality, and the key characteristics emphasized in recruiting teachers into quality early childhood education. For the participants, quality early childhood education embodies three key components: safety, nutrition, and teaching. Cognitive development, social skills, and leadership abilities were emphasized as some of the benefits of quality early childhood education for children. Regarding the recruitment of teachers, participants emphasized tertiary education rather than attitudinal and behavioral qualities as relevant for teachers in early childhood education. In view of the emphasis placed on nutrition in defining quality, we recommend that advocacy groups must ensure that the government’s school feeding program extends to day care centers. This will go a long way to ensure that children from poor households are not excluded from the benefits of quality early childhood education.
Mixed Convection of a Radiating Magnetic Nanofluid past a Heated Permeable Stretching/Shrinking Sheet in a Porous Medium
Authors: Tadesse Feleke Buta , Makinde Oluwole Daniel , Enyadene Lemi Guta
Published: June 2021

This paper analyzes the collective effects of buoyancy force, thermal radiation, convective heating, and magnetic field on stagnation point flow of an electrically conducting nanofluid past a permeable stretching/shrinking sheet in a porous medium. Similarity transformations are used on the resulting nonlinear partial differential equations to transfer into a system of coupled nonlinear ordinary differential equations. The fourth-fifth-order Runge–Kutta–Fehlberg method with shooting technique is applied to solve numerically. Results are obtained for dimensionless velocity, temperature, and nanoparticle volume fraction as well as the skin friction and local Nusselt and Sherwood numbers. The results indicate the existence of two real solutions for the shrinking sheet in the range of

λ

c

<
λ
<
0

. The fluid flow stability is maintained by increasing the magnetic field effect, whereas the porous medium parameter inflates the flow stability. It is also noted that both the skin friction coefficient and the local Sherwood number approximately decline with the intensification of thermal radiation within the range from 9.83% to 14% and the range from 48.86% to 78.66%, respectively. It is also evident in the present work that the local Nusselt number upsurges with the porous and suction/injection parameters.
Loss of Gas7 Is a Key Metastatic Switch in Neuroblastoma
Authors: Menard Marie J.
Published: June 2021

Metastatic spread to distant tissues and organs is responsible for most cancer-related mortalities. Changes in the invasiveness ability of metastatic tumor cells often come with significantly altered gene expression profiles compared with primary tumor cells. Identifying the main actors involved in the metastatic switch of tumor cells is key to proposed new therapeutic approaches. In this issue, the loss of growth-arrest specific 7 is described as one of the main events driving metastatic spread in neuroblastoma.

See related article by Dong et al., p. 2995
Association between Circulating Protein C Levels and Incident Dementia: The Atherosclerosis Risk in Communities Study
Authors: Tin Adrienne , Walker Keenan A. , Bressler Jan , Windham B. Gwen , Griswold Michael , Sullivan Kevin , Wu Aozhou , Gottesman Rebecca , Fornage Myriam , Coresh Josef , Sharrett A. Richey , Folsom Aaron R. , Mosley Thomas H.
Published: June 2021

Introduction: Hemostasis depends on the delicate balance between coagulants and anticoagulants. Higher levels of circulating coagulants have been associated with higher risk of cerebral infarctions and dementia. In contrast, higher levels of circulating protein C, an endogenous anticoagulant, have been associated with lower risk of cerebral infarctions, and the association between protein C levels and the risk of dementia is unknown. The goal of this study was to evaluate the association of circulating protein C levels in midlife and late life with incident dementia. Methods: Circulating protein C levels were measured using blood samples collected at the midlife baseline (1987–1989) and the late-life baseline (2011–2013) among 14,462 and 3,614 participants, respectively, in the Atherosclerosis Risk in Communities study. Protein C levels were measured using enzyme-linked immunosorbent assay at midlife and a modified aptamer-based assay at late life. Participants were followed up to 2013 from midlife and up to 2017 from late life. Incident dementia was ascertained during the follow-up periods using in-person cognitive and functional assessment, informant interviews, and International Classification of Diseases codes at hospitalization discharge and on death certificates. Cause-specific Cox regression models were used to evaluate the association between quintiles of circulating protein C and incident dementia. Results: From midlife (mean age of 54), 1,389 incident dementia events were observed over a median follow-up of 23 years. From late life (mean age of 75), 353 incident dementia events were observed over a median follow-up of 4.9 years. At both midlife and late life, circulating protein C had an inverse association with incident dementia after adjusting for demographic, vascular, and hemostatic risk factors, incident stroke as time-dependent covariate, and incorporating stabilized weights based on propensity scores (quintile 5 vs. quintile 1 as the reference, midlife hazard ratio 0.80, 95% confidence interval 0.66–0.96, p value for trend 0.04; late-life hazard ratio 0.84, 95% confidence interval: 0.55–1.28, p value for trend 0.04). Discussion/Conclusion: Circulating protein C has an inverse association with incident dementia independent of established risk factors, including stroke. Our results suggest studying anticoagulants in addition to coagulants can increase our understanding on the relationship between hemostasis and dementia.