Mechanical dissection in an introductory engineering design module

The introductory design module for first year students in the Department of Mechanical Engineering at the University of Strathclyde uses mechanical dissection as a focus for learning activities that seek to integrate engineering science with the prior knowledge of the students. First year groups select and remove components from a scrap motor car, and produce a technical description of the system including consideration of function, mechanics, materials and manufacturing processes. Personal and professions skills and interpersonal skills are developed through enquiry based learning. This encourages the students to identify problems and engage in analysis requiring estimation and uncertainty; sourcing information in a critical manner to integrate in their description of the chosen component. Group and communication skills are developed through peer discussion and the presentation of their research in the form of a poster and formal seminar. Student feedback indicates a high level of enjoyment of, and engagement in many of the learning activities. However, focus group interviews and questionnaire responses indicate that the key area of metallurgy has proved to be difficult for many students, probably due to a lack of relevant background knowledge. Further development of the learning activities in metallurgy is planned, including pre-reading and peer instruction to prepare the students for the staff-led materials examination sessions. Continuing evaluation of the learning experiences of the students will be undertaken to assess the effectiveness of these developments

Tests of the ratio rule in categorization

Many theories of learning and memory (e.g. connectionist, associative, rational, exemplar-based) produce psychological magnitude terms as output (i.e. numbers representing the momentary level of some subjective property). Many theories assume that these numbers may be translated into choice probabilities via the Ratio Rule, a.k.a. the Choice Axiom (Luce, 1959) or the Constant-Ratio Rule (Clarke, 1957). We present two categorization experiments employing artificial, visual, prototype-structured stimuli constructed from twelve symbols positioned on a grid. The Ratio Rule is shown to be incorrect for these experiments, given the assumption that the magnitude terms for each category are univariate functions of the number of category-appropriate symbols contained in the presented stimulus. A connectionist winner-take-all model of categorical decision (Wills & McLaren, 1997) is shown to account for our data given the same assumption. The central feature underlying the success of this model is the assumption that categorical decisions are based on a Thurstonian choice process (Thurstone, 1927, Case V) whose noise distribution is not double exponential in form

Prevalence, genetic relationships and pathogenicity of intestinal spirochaetes infecting Australian Poultry

The prevalence of infection with intestinal spirochaetes in chickens in Western Australia was assessed by selective culture of faecal samples. Colonisation was common, with 35.1% of layer flocks and 53.3% of broiler breeder flocks being positive. Spirochaetes were recovered significantly more frequently from flocks with diarrhoea or reduced production than from clinically normal flocks. The genetic identity and diversity of 56 selected isolates from Australia, the USA and Europe were examined using multilocus enzyme electrophoresis: these were divided into six diverse genetic groups. Three groups contained isolates previously shown to be pathogenic for chickens: (i) "Serpulina intermedia ", (ii) an unnamed group (not identified in Australia), and (iii) Serpulina pilosicoli. Most pathogenic isolates from Australia were "S. intermedia ". Day-old broiler chicks were infected orally with Australian isolates either of "S. intermedia" (3), a commonly isolated but unnamed group (3), or S. pilosicoli (1). All spirochaetes induced diarrhoea, but this occurred earlier and more birds were colonised with "S. intermedia" and S. pilosicoli strains than with strains from the unnamed group. Infection of laying hens with an "S. intermedia " strain caused wet faeces and reduced egg production

The Spinel LiCoMnO4: 5V cathode and conversion anode

LiCoMnO4 was made at 550 °C in 2 h using a novel biotemplating synthetic methodology. High temperature heat treatment under flowing N2 was then used to prepare the cation-disordered rock salt, LiCoMnO3. We demonstrate for the first time that both phases can operate as conversion anodes in lithium-ion batteries, operating at ~ 0.7 V with specific capacities of ~ 400 mAh g-1. We also demonstrate that 1,3-propane sultone can be used as an electrolytic additive to provide a modest boost to specific capacity in cells cycled at high potentials with LiCoMnO4 as the cathode

Evaluating use cases for human challenge trials in accelerating SARS-CoV-2 vaccine development

Human challenge trials (HCTs) have been proposed as a means to accelerate SARS-CoV-2 vaccine development. We identify and discuss three potential use cases of HCTs in the current pandemic: evaluating efficacy, converging on correlates of protection, and improving understanding of pathogenesis and the human immune response. We outline the limitations of HCTs and find that HCTs are likely to be most useful for vaccine candidates currently in preclinical stages of development. We conclude that, while currently limited in their application, there are scenarios in which HCTs would be extremely beneficial. Therefore, the option of conducting HCTs to accelerate SARS-CoV-2 vaccine development should be preserved. As HCTs require many months of preparation, we recommend an immediate effort to (1) establish guidelines for HCTs for COVID-19; (2) take the first steps toward HCTs, including preparing challenge virus and making preliminary logistical arrangements; and (3) commit to periodically re-evaluating the utility of HCTs

Archaeology and Desertification in the Wadi Faynan: the Fourth (1999) Season of the Wadi Faynan Landscape Survey

Reproduced with permission of the publisher. © 2000 Council for British Research in the Levant. Details of the publication are available at: http://www.cbrl.org.uk/Publications/publications_default.shtmThis report describes the fourth season of fieldwork by an interdisciplinary team of archaeologists and geographers working together to reconstruct the landscape history of the Wadi Faynan in southern Jordan. The particular focus of the project is the long-term history of inter-relationships between landscape and people, as a contribution to the study of processes of desertification and environmental degradation. The 1999 fieldwork contributed significantly towards the five Objectives defined for the final two field seasons of the project in 1999 and 2000: to map the archaeology outside the ancient field systems flooring the wadi that have formed the principal focus of the archaeological survey in the previous seasons; to use ethnoarchaeological studies both to reconstruct modern and recent land use and also to yield archaeological signatures of land use to inform the analysis of the survey data; to complete the survey of ancient field systems and refine understanding of when and how they functioned; to complete the programme of geomorphological and palaeoecological fieldwork, and in particular to refine the chronology of climatic change and human impacts; and to complete the recording and classification of finds

The forkhead transcription factor FOXL2 is expressed in somatic cells of the human ovary prior to follicle formation

Interactions between germ cells and surrounding somatic cells are central to ovarian development as well as later function. Disruption of these interactions arising from abnormalities in either cell type can lead to premature ovarian failure (POF). The forkhead transcription factor FOXL2 is a candidate POF factor, and mutations in the FOXL2 gene are associated with syndromic and non-syndromic ovarian failure. Foxl2-deficient mice display major defects in primordial follicle activation with consequent follicle loss, and earlier roles in gonadal development and sex determination have also been suggested. However, despite its importance no data presently exist on its expression in the developing human ovary. Expression of FOXL2 mRNA was demonstrated in the human fetal ovary between 8 and 19 weeks gestation, thus from soon after sex determination to primordial follicle development. Expression in the ovary was higher after 14 weeks than at earlier gestation weeks and was very low in the fetal testis at all ages examined. Immunolocalization revealed FOXL2 expression to be confined to somatic cells, both adjacent to germ cells and those located in the developing ovarian stroma. These cells are the site of action of oocyte-derived activin signalling, but in vitro treatment of human fetal ovaries with activin failed to reveal any regulation of FOXL2 transcription by this pathway. In summary, the expression of FOXL2 in somatic cells of the developing human ovary before and during follicle formation supports a conserved and continuing role for this factor in somatic/germ cell interactions from the earliest stages of human ovarian development

Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio

Observation of a new chi_b state in radiative transitions to Upsilon(1S) and Upsilon(2S) at ATLAS

The chi_b(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4 fb^-1, these states are reconstructed through their radiative decays to Upsilon(1S,2S) with Upsilon->mu+mu-. In addition to the mass peaks corresponding to the decay modes chi_b(1P,2P)->Upsilon(1S)gamma, a new structure centered at a mass of 10.530+/-0.005 (stat.)+/-0.009 (syst.) GeV is also observed, in both the Upsilon(1S)gamma and Upsilon(2S)gamma decay modes. This is interpreted as the chi_b(3P) system.Comment: 5 pages plus author list (18 pages total), 2 figures, 1 table, corrected author list, matches final version in Physical Review Letter

Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS

We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutralino lifetime. Limits are presented for different squark and neutralino masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final version to appear in Physics Letters