Making science real:Photo-sharing in biology and chemistry

In this paper, we examine students’ reflections about the value of two photo-sharing activities that were implemented in undergraduate Biology and Chemistry subjects. Both activities aimed, broadly, to provide support for authentic and meaningful learning experiences in undergraduate science. Although the activities were similar – both required students to capture and share images as part of an independent inquiry activity – students in the Biology case study were more positive, overall, than the Chemistry students in their evaluation of the activity. In this paper, we examine the findings from the two case studies in parallel to provide insight into our understanding of meaningful learning in undergraduate science. The results suggest that, for meaningful learning to occur, the learning activity needs to be well aligned with students’ individual learning goals and with the objectives and characteristics of the course. In the two case studies examined in this paper, this alignment was successful for the Biology case study but less successful in the Chemistry case study

Thermal insulating conformal blanket

The conformal thermal insulating blanket may have generally rigid batting material covered by an outer insulating layer formed of a high temperature resistant woven ceramic material and an inner insulating layer formed of a woven ceramic fiber material. The batting and insulating layers may be fastened together by sewing or stitching using an outer mold layer thread fabricated of a high temperature resistant material and an inner mold layer thread of a ceramic fiber material. The batting may be formed to a composite structure that may have a firmness factor sufficient to inhibit a pillowing effect after the stitching to not more than 0.03 inch. The outer insulating layer and an upper portion of the batting adjacent the outer insulating layer may be impregnated with a ceramic coating material

Low-Density, Aerogel-Filled Thermal-Insulation Tiles

Aerogel fillings have been investigated in a continuing effort to develop low-density thermal-insulation tiles that, relative to prior such tiles, have greater dimensional stability (especially less shrinkage), equal or lower thermal conductivity, and greater strength and durability. In preparation for laboratory tests of dimensional and thermal stability, prototypes of aerogel-filled versions of recently developed low-density tiles have been fabricated by impregnating such tiles to various depths with aerogel formations ranging in density from 1.5 to 5.6 lb/ft3 (about 53 to 200 kg/cu m). Results available at the time of reporting the information for this article showed that the thermal-insulation properties of the partially or fully aerogel- impregnated tiles were equivalent or superior to those of the corresponding non-impregnated tiles and that the partially impregnated tiles exhibited minimal (<1.5 percent) shrinkage after multiple exposures at a temperature of 2,300 F (1,260 C). Latest developments have shown that tiles containing aerogels at the higher end of the density range are stable after multiple exposures at the said temperature

Hybrid aerogel rigid ceramic fiber insulation and method of producing same

A hybrid insulation material comprises of porous ceramic substrate material impregnated with nanoporous material and method of making the same is the topic of this invention. The porous substrate material has bulk density ranging from 6 to 20 lb/ft.sup.3 and is composed of about 60 to 80 wt % silica (SiO.sub.2) 20 to 40 wt % alumina (Al.sub.2 O.sub.3) fibers, and with about 0.1 to 1.0 wt % boron-containing constituent as the sintering agent. The nanoporous material has density ranging from 1.0 to 10 lb/ft.sup.3 and is either fully or partially impregnated into the substrate to block the pores, resulting in substantial reduction in conduction via radiation and convention. The nanoporous material used to impregnate the fiber substrate is preferably formed from a precursor of alkoxysilane, alcohol, water, and an acid or base catalyst for silica aerogels, and from a precursor of aluminum alkoxide, alcohol, water, and an acid or base catalyst for alumina aerogels

Molecular variability of three genes of potato vein yellow virus infecting Solanum tuberosum, using single strand conformational polymorphism

Potato yellow vein virus (PYVV), a virus with tripartite RNA (ss+) genome is classified as member of the genus Crinivirus within the family Closteoviridae. PYVV is the causal agent of potato yellow vein disease (PYVD) with yield loss between 25 %–50 % in field. Single strand conformational polymorphism (SSCP) has been reported to estimate variability in different viruses’ species. In this study, the molecular variability of PYVV analyzed by SSCP patterns of three genes: major capsid protein (CP), minor capsid protein (CPm), and heat shock protein (Hsp70) obtained from 60 virus isolates from potato plants expressing PYVD. Leaves collected in Nariño, Colombia from 30 Solanum tuberosum Phureja Group (PhG) and 30 from the Andigena Group (AG). Genes amplified by RT-PCR and the purified PCR products used for SSCP. Three SSCP patterns detected for the CP gene, 12 for CPm and 12 for Hsp70. The pattern C was the most frequent for the Hsp70 gene and the pattern IV (33.3 %) for CPm gene in the Andigena Group. The pattern 1 for CP gene was present in 93.3 % of both host groups, indicating low number of variants compared to the CPm and Hsp70 genes. This is the first attempt to estimate intra e inter PYVV variability by the use of a simple molecular method considering three genes in a large group of potato samples affected by PYVD. SSCP technique was useful to evaluate the viral variability.Potato yellow vein virus o virus del amarillamiento de venas de la hoja de la papa (PYVV) es un virus RNA tripartito (ss+) de la familia Closteroviridae género Crinivirus que causa la enfermedad de amarillamiento de nervaduras de la hoja de papa (PYVD) reduciendo la productividad, entre el 25 % y 50 %. La técnica de polimorfismo conformacional de cadena sencilla (SSCP) ha sido usada para estimar la variabilidad en diferentes especies de virus. En el presente trabajo se analizó la variabilidad molecular de 60 aislados de PYVV a partir de la comparación de tres genes: el gen de la proteína mayor de la cápside (CP), proteína menor de la cápside (CPm) y la proteína de choque térmico (Hsp70). Los aislados se obtuvieron de dos grupos de Solanum tuberosum: 30 del Grupo Phureja (GPh) y 30 del Grupo Andígena (GA), provenientes del departamento de Nariño, Colombia. Los genes se amplificaron por RT-PCR y los productos purificados se emplearon para SSCP en geles de poliacrilamida. Se detectaron tres perfiles de SSCP para el gen CP, 12 para el CPm y 12 para el Hsp70. Para el GA el perfil más frecuente del gen Hsp70 fue el perfil C (66,6 %) y para el gen CPm fue el IV (33,3 %). Para el gen CP, el patrón uno se encontró en el 93,3 % de los aislados, indicando menor variabilidad. Esta es la primera estimación de variabilidad de PYVV en diferentes genes y a través de una técnica molecular simple

The potential of virtual laboratories for distance education science teaching: reflections from the development and evaluation of a virtual chemistry laboratory

A virtual chemistry laboratory has been developed at Charles Sturt University, based on an accurate 3D model of the Wagga Wagga undergraduate teaching laboratory. The initial version of the virtual laboratory has been designed to enable distance education chemistry students to become familiar with the laboratory prior to their residential school. It allows for free exploration and for collecting and assembling items of apparatus. It also allows students to read information about the items of apparatus and about laboratory procedures. This paper describes the current features of the virtual laboratory and discusses the pedagogical rationale for its development. Results from questionnaires completed by pilot testers and by the first group of students who used it as part of their laboratory orientation are included. The results of tests comparing the laboratory familiarity of students who used the virtual laboratory with those who viewed equivalent still images are also presented. The paper concludes with a description of features to be added during the next stage of development, which will include the ability for students to undertake virtual experiments while exploring concepts using macroscopic, molecular and symbolic representations

Inter and Intra Variation of Potato Yellow Vein Virus in Three Potato Species From Colombia

Abstract. Potato yellow vein virus (PYVV), (family Closteroviridae, genus Crinivirus) is a re-emergent virus in Andean countries. Low inter-isolate variation has been reported for PYVV CP gene, but there are no reports for intra-isolate variation. Inter- and intra-isolate variability in CP from a population of PYVV was studied. Samples of 216 symptomatic potato plants (115 Solanum tuberosum subsp. andigena (STA), 100 Solanum phureja (SPH) and 1 Solanum chaucha (SCH)) were collected in five Colombian departments. Viral isolates were amplified by RT-PCR and the amplicons were analyzed by single-strand conformation polymorphism (SSCP). Six different migration SSCP patterns (A to F) with different complexities were observed among the population. Pattern A was detected in the five departments in 66% of the isolates. Pattern E was found only in the department of Cundinamarca with a frequency of 0.09%. Patterns B, C, D and F were found in similar proportions of from 13% to 5.6% and were present in the five departments. Homology at the nucleotide level of 75% of the sequence of the CP gene was greater than 99% and the dN/dS ratio (no-synonymous/ synonymous changes) was 0.002. Amplicons of the whole CP gene of eight selected isolates representing the six SSCP patterns were cloned and the SSCP analysis showed that, in all cases, more than one variant was present. The sequence analysis of the 35 clones confirmed intra-isolate variability of PYVV. The existence of several variants in a single field isolate was demonstrated and negative selection against amino acid changes of the CP was suggested.  /  Resumen. Potato yellow vein virus (PYVV), (familia Closteroviridae, género Crinivirus) es un virus re-emergente para los países Andinos. Se ha reportado baja variación del gen CP de PYVV entre aislados, pero no hay reportes de variación intra aislado. Se estudió tanto la variación inter como intra aislado del CP de una población de PYVV. Muestras de 216 plantas de papa sintomáticas (115 Solanum tuberosum subsp. andigena (STA), 100 Solanum phureja (SPH) y 1 Solanum chaucha (SCH)) se colectaron en 5 departamentos de Colombia. Los aislados se amplificaron por RT-PCR y los amplicones se analizaron por polimorfismo conformacional de cadena sencilla (SSCP). Se observaron seis patrones de migración de SSCP distintos (A a F) con diferentes complejidades. El patrón A fue detectado en cinco departamentos en 66% de los aislados y el E solo en el departamento de Cundinamarca con una frecuencia de 0,09%. Los patrones B, C, D y F se encontraron en proporciones similares entre 13% a 5,6%, y estuvieron presentes en los cinco departamentos. La homología de nucleótidos del 75% de la secuencia del gen CP fue mayor del 99% y la tasa dN/dS (cambios no sinónimos/ cambios sinónimos) fue de 0,002. Amplicones del gen completo de CP de ocho aislados que representaban los seis patrones de SSCP se clonaron y un análisis SSCP mostró que todos tenían más de una variante. El análisis de secuencias de 35 clones confirmó la variabilidad intra aislado de PYVV. La existencia de varias variantes en un solo aislado de campo se demostró y se sugiere selección negativa de cambios de aminoácidos en al CP

What factors contribute to students’ confidence in chemistry laboratory sessions and does preparation in a virtual laboratory help?

Many undergraduate students studying chemistry subjects at Charles Sturt University (CSU) do so by Distance Education (DE). CSU has been offering subjects in chemistry in distance mode for more than 20 years. One of the greatest problems that confronts us, and others (Hollingworth and McLoughlin 2001; Kennepohl and Last 2000) in providing DE subjects is how to adequately address the teaching of a laboratory component. The practical work for CSU DE chemistry subjects is completed at intensive three or four day residential schools. Thus, DE students have only a few days to face the challenges that are spread out over many weeks for on-campus students. Providing a quality laboratory experience for these students within that short period and within the constraints of our resources is the subject of ongoing review at CSU. Problems associated with high stress and information overload for the laboratory component in DE had been noted anecdotally and in the literature (e.g., Loonat 1996). Adequately preparing DE students for residential school is a difficult task. One strategy we have adopted to help prepare DE students has been the provision on CD-ROM of a 3D virtual laboratory, which is an accurate representation of the teaching laboratories. In a paper at last year’s UniServe Symposium (Dalgarno, Bishop and Bedgood 2003), we hypothesised that as a pre-laboratory familiarisation tool, the virtual laboratory would include the following potential benefits: • students would feel more relaxed and comfortable in the laboratory; • less laboratory time would be wasted looking for items of apparatus; • students would be more likely to assemble and use apparatus in the correct way leading to more meaningful experimental results; and • students could devote more of their attention to the chemistry concepts involved in the experiments because they would already be familiar with the procedural aspects of the task (p. 91). This paper presents the results of a qualitative and quantitative study of the laboratory experience of DE students in first year chemistry subjects which provides initial tests of these hypotheses, as well as expanding our understanding of factors involved with the student experience of laboratory

Contemporary and historical human migration patterns shape hepatitis B virus diversity

Funding Information: BIP and GB acknowledge support from the Internal Funds KU Leuven (Grant No. C14/18/094). GB acknowledges support from the Research Foundation—Flanders (‘Fonds voor Wetenschappelijk Onderzoek—Vlaanderen’, G0E1420N, G098321N). PL acknowledges support from the Research Foundation—Flanders (‘Fonds voor Wetenschappelijk Onderzoek—Vlaanderen’, G0D5117N, G0B9317N, G051322N). The opinions expressed in this article are those of the authors and do not reflect the view of the National Institutes of Health, the Department of Health and Human Services, or the United States government. Publisher Copyright: © 2024 Oxford University Press. All rights reserved.Infection by hepatitis B virus (HBV) is responsible for approximately 296 million chronic cases of hepatitis B, and roughly 880,000 deaths annually. The global burden of HBV is distributed unevenly, largely owing to the heterogeneous geographic distribution of its subtypes, each of which demonstrates different severity and responsiveness to antiviral therapy. It is therefore crucial to the global public health response to HBV that the spatiotemporal spread of each genotype is well characterized. In this study, we describe a collection of 133 newly sequenced HBV strains from recent African immigrants upon their arrival in Belgium. We incorporate these sequences—all of which we determine to come from genotypes A, D, and E—into a large-scale phylogeographic study with genomes sampled across the globe. We focus on investigating the spatio-temporal processes shaping the evolutionary history of the three genotypes we observe. We incorporate several recently published ancient HBV genomes for genotypes A and D to aid our analysis. We show that different spatio-temporal processes underlie the A, D, and E genotypes with the former two having originated in southeastern Asia, after which they spread across the world. The HBV E genotype is estimated to have originated in Africa, after which it spread to Europe and the Americas. Our results highlight the use of phylogeographic reconstruction as a tool to understand the recent spatiotemporal dynamics of HBV, and highlight the importance of supporting vulnerable populations in accordance with the needs presented by specific HBV genotypes.publishersversionpublishe

Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO