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As virtual reality (VR) technology becomes cheaper, higher-quality, and more widely available, it is seeing increasing use in a variety of applications including cultural heritage, real estate, and architecture. A common goal for all these applications is a compelling virtual recreation of a real place. Despite this, there has been very little research into how users perceive and experience such replicated spaces. This article reports the results from a series of three user studies investigating this topic. Results include that the scale of the room and large objects in it are most important for users to perceive the room as real and that non-physical behaviors such as objects floating in air are readily noticeable and have a negative effect even when the errors are small in scale. [ABSTRACT FROM AUTHOR]

Undergraduate students of fluid mechanics bring a range of preconceptions to the classroom. The sometimes counterintuitive nature of fluid mechanics means that many of these preconceptions are, in fact, misconceptions. Such misconceptions can be hard to address and can persist even among nominally high-performing students. A pedagogical approach (i.e., predict, test, and reflect) is presented. The approach provides an effective structure for addressing and correcting misconceptions through the use of low-cost hands-on activities that students can quickly and easily undertake during regular class time. The activities all have the same structure of describing the activity, having students make a prediction based on their intuition/prior experience, testing that prediction using simple, low-cost activities, reflecting on the success or failure of the prior prediction, and analysis of the activity to illustrate the correct conception of the flow. Course evaluations indicate that students have found this approach very helpful in improving their conceptual understanding in an introductory engineering fluid mechanics class. [ABSTRACT FROM AUTHOR]

Janis Stradins (10.12.1933 – 29.11.2019) was a well-known expert in molecular electrochemistry, ESR spectroscopy and physical organic chemistry, as well as in history of sciences. His main works in electrochemistry were connected with organic molecules single electron reduction and oxidation primary and secondary products studies, these species ESR spectra hyperfine structure investigations, supplying data on various organic molecules groups' reactivity, demonstrating abilities of electrochemical studies for organic compounds reaction prediction. He was ISE member, past president of Latvian Academy of Sciences, full member of European Academy of Sciences and Arts, from 2011 its Honorary Senator. [ABSTRACT FROM AUTHOR]

Arc chutes comprising ferromagnetic splitter plates are common in SF6-insulated medium-voltage switchgears. By splitting and cooling the electric arc, they help to interrupt moderate currents such as the rated current in load break switches or the transfer current in switch–fuse combinations. Between the splitter plates of such an arc chute, the motion of the arc depends on the balance of the attracting magnetic forces from the ferromagnetic plates, the repelling forces between two arc columns at the two sides of a plate, and the viscous forces from the insulating gas. We simulated this motion by calculating the magnetic forces acting on the arc columns after splitting by means of 2-D and 3-D electromagnetic finite-element analyses and by taking the viscous force as drag force into account. This paper describes this calculation method and compares the simulation results with those of laboratory tests. [ABSTRACT FROM AUTHOR]

This study explored the culture of a high school girls' cross-country team. Of interest was whether and how interactions with coaches and athletes contributed to athletes' body-related attitudes and behaviors. Data were collected via participant observation and in-depth interviews. Constant comparison processes were used to analyze the data. Findings revealed a team culture emphasizing values of unity/harmony and healthfulness. In turn, these values framed individual experiences of the body and team interactions. All athletes expressed relatively positive feelings about the body, and none of the athletes reported regularly dieting. The following two patterns of body-related athlete-athlete interactions emerged: fat talk and deferential avoidance. The following three patterns of body-related coach-athlete interactions were identified: verbal interventions for regulation of athlete attitudes and behaviors, deferential avoidance, and condemnations and censures. Analyses suggested that in a variety of ways, these interaction patterns set a context for the athletes' body-related attitudes and behaviors.

This interpretive study explored body-related content in Seventeen magazine, a fashion and beauty magazine for adolescent girls, from 1992 to 2003 (inclusive). The authors work was guided by symbolic convergence theory, which illuminates how rhetorical visions within media can contribute to audience perceptions of reality. Analyses revealed the following two main rhetorical visions within Seventeen: (1) the making of body problems and (2) the unmaking of body problems. Content related to Rhetorical Vision 1 simultaneously constructed a narrow constellation of body characteristics as ideal and problematized bodies that deviated from this ideal. Content related to Rhetorical Vision 2 provided the following three different mechanisms for dealing with body problems: (a) controlling the body through bodywork regimens, (b) controlling the body through consumption, and (c) staging resistance against dominant cultural discourses about the body (e.g., the thin ideal). Findings suggest that rhetorical visions presented within Seventeen may send mixed messages to adolescents about their bodies.

We used DNA restriction fragments, derived from the exotoxin A gene and surrounding sequences, as an epidemiological marker for Pseudomonas aeruginosa. Using these DNA fragments as probes in Southern blot hybridizations and/or total genomic digestions, we were able to distinguish greater than 100 different strains of P. aeruginosa. The stability of the marker in vitro was established by using well-characterized strains, which were stored under different conditions and subjected to chemical mutagenesis. The stability of the marker within a given strain in vivo was established during experimental infection in the chronic rat lung model of pseudomonas pneumonia. P. aeruginosa serially cultured from individual patients with cystic fibrosis were examined by using this marker. Isolates that varied in colonial morphology, serotype, and biotype were identical when analyzed by Southern blot hybridization using the fragment as a probe. Indistinguishable isolates (by serotyping, biotyping, and antibiograms) cultured from two unrelated patients were easily distinguished by using Southern blot analysis. [ABSTRACT FROM AUTHOR]

When uranium-niobium alloys containing between 13.9 and 17.9 at. pct Nb are quenched to room temperature from the BCC (γ) phase at elevated temperatures, diffusion-controlled precipitation of the equilibrium phases is prevented and martensitic transformations to transition phases occur instead. Dilatometry was used to detect transformation temperatures and with the help of X-ray diffraction analysis, a metastable phase diagram was established. At room temperature after quenching, alloys containing < 15.2 at. pct Nb were monoclinic (α″) and those with < 16.6 at. pct Nb were tetragonal (γ°). The deformation behavior and shape memory effects (SME) accompanying the reverse martensitic phase transformations in polycristalline specimens were surveyed and characterized phenomelogically. From uniaxial tensile tests at room temperature, macroscopic stress-strain parameters, associated with the reversible deformation modes in the α″ and γ° martensites, were defined and their composition and structural state dependencies delineated. A diffuse maximum manifested in the stress-strain diagrams was identified with the reversible strain limit, which varied inversely and continuously with composition. A concentration-independent value of 693 MPa was found for the plastic yield strength of the alloys. All the alloys exhibited heat-activated shape recovery but the degree depended on structural state and composition. The α″ alloys showed a much larger effect than γ° alloys. Shape recovery occurred in two stages in all alloys. The first stage of recovery accompanied martensite reversion but final reversion to the equilibrium y phase was not accomplished until much higher temperatures were reached. Rapid, low temperature aging reactions were thought to affect the finish of shape recovery and delay it to higher temperatures. [ABSTRACT FROM AUTHOR]

After a brief historical introduction to Council Directives relating to the manufacture of radiopharmaceuticals the work of the Association of Radiopharmaceuticals Producers — Europe (ARPE) is discussed. ARPE has played a significant role as an officially recognized interlocutor with the EEC, influencing decisions on the registration of radiopharmaceuticals and labelling; this role is reviewed and difficulties identified. The future of radiopharmaceuticals is then considered; it is emphasized that harmonization of national laws by the European Council would represent a first step to enabling radiopharmaceutical manufacturers to access the largest possible market for their products. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "Awareness and the use of nutritional supplementation for age-related macular degeneration (AMD) patients," by M. Waisbourd and colleagues.

A letter to the editor is presented in response to the article eccentric macular hole formation associated with macular hole surgery.