Pion Charge Exchange on Deuterium

We investigate quantum corrections to a classical intranuclear cascade simulation of pion single charge exchange on the deuteron. In order to separate various effects the orders of scattering need to be distinguished and, to that end, we develop signals for each order of scattering corresponding to quasi-free conditions. Quantum corrections are evaluated for double scattering and are found to be large. Global agreement with the data is good.Comment: 30 pages, 12 figure

The pentaquark in K-plus-d total cross section data

An analysis of $K^+$-d total cross section data is undertaken to explore possible effects of the recently observed resonance in the S=+1 hadronic system with mass around 1.55 GeV. It is found that a structure corresponding to the resonance is visible in the data. The width consistent with the observed deviation from background is found to be $0.9\pm 0.3$ MeV and the mass is $1.559\pm 0.003$ GeV/c$^2$ for spin-parity \h^+ and $1.547\pm0.002$\ GeV/c$^2$ for \h^-. The errors are one standard deviation and statistical only. \Comment: 10 pages, 5 figures Replaced to correct references, add and correct text. No change in content. More discussion of errors, increased error on width, corrected one figur

Homologous Recombination under the Single-Molecule Fluorescence Microscope

Homologous recombination (HR) is a complex biological process and is central to meiosis and for repair of DNA double-strand breaks. Although the HR process has been the subject of intensive study for more than three decades, the complex protein–protein and protein–DNA interactions during HR present a significant challenge for determining the molecular mechanism(s) of the process. This knowledge gap is largely because of the dynamic interactions between HR proteins and DNA which is difficult to capture by routine biochemical or structural biology methods. In recent years, single-molecule fluorescence microscopy has been a popular method in the field of HR to visualize these complex and dynamic interactions at high spatiotemporal resolution, revealing mechanistic insights of the process. In this review, we describe recent efforts that employ single-molecule fluorescence microscopy to investigate protein–protein and protein–DNA interactions operating on three key DNA-substrates: single-stranded DNA (ssDNA), double-stranded DNA (dsDNA), and four-way DNA called Holliday junction (HJ). We also outline the technological advances and several key insights revealed by these studies in terms of protein assembly on these DNA substrates and highlight the foreseeable promise of single-molecule fluorescence microscopy in advancing our understanding of homologous recombination

AN ANALYSIS OF THE EFFECT OF PRICE ON RESIDENTIAL WATER DEMAND: METROPOLITAN MIAMI, FLORIDA

Resource /Energy Economics and Policy,

Geomagnetic modeling by optimal recursive filtering

The results of a preliminary study to determine the feasibility of using Kalman filter techniques for geomagnetic field modeling are given. Specifically, five separate field models were computed using observatory annual means, satellite, survey and airborne data for the years 1950 to 1976. Each of the individual field models used approximately five years of data. These five models were combined using a recursive information filter (a Kalman filter written in terms of information matrices rather than covariance matrices.) The resulting estimate of the geomagnetic field and its secular variation was propogated four years past the data to the time of the MAGSAT data. The accuracy with which this field model matched the MAGSAT data was evaluated by comparisons with predictions from other pre-MAGSAT field models. The field estimate obtained by recursive estimation was found to be superior to all other models

H2S paper strip method - A bacteriological test for faecal coliforms in drinking water at various temperatures

Epidemics arising from waterborne diseases are a global health problem. Faecal contamination of drinking water is the main cause of these outbreaks. According to WHO (1996) for drinking water to be safe, a 100 ml sample should not contain any coliform bacteria. The standard methods currently used for routine testing have many limitations especially when applied in remote areas. The H2S method has been developed as an on-site, inexpensive and easy to use method to test drinking water for remote and rural areas. The present work analyses the reliability of the H2S method for detecting faecal contamination in drinking water. The minimum level of faecal coliforms that could be detected and the incubation period required at various levels of contamination were studied. The range of temperatures at which the method was effective and the incubation period required at various temperatures were also determined. The H2S method was found to be able to detect contamination down to a level of 1 CFU/100 ml of coliform bacteria. Although the H2S method could be used at a temperature range of 20 to 44oC, temperatures between 28 to 37oC gave faster results. An incubation period of only 24 hours was required at 37oC, which was found to be the most suitable incubation temperature. The incubation period increased with a decrease or increase in temperature

Video and visual resources & technologies in teaching statistics

This presentation takes a wide definition of visual to include video and presentation technologies. It discusses the availability of video resources about stats (conceptual and SPSS tutorials) and about some of the other visual technologies that are used and could be used here. This includes drawing/annotation and recording systems that can be used to create video materials (a bit like the Kahn University videos) - including some interesting apps on the iPad (e.g. Explain Everything). It comments on the pros and cons of identifying good videos and of using them in sessions and as additional course resources

STEM in Teaching Qualitative Research

Abstract The results from the first stage of a project examining the use of computer assisted qualitative data analysis (CAQDAS) and mixed methods teaching in qualitative analysis to promote numeric and technology skills in undergraduate students. Results from a survey of qualitative research teachers carried out as part of the project will be presented. Overview This paper will report the preliminary results from an online survey of teachers of qualitative research methods (Survey 2), which has been undertaken as part of a project to determine what barriers there are to the inclusion in undergraduate qualitative methods teaching of skills relating to the use of CAQDAS programs and the use of mixed methods in research designs. The project will also try to discover and summarise good practice and to develop guidelines for such teaching content that can be used at undergraduate level, though the full details of this will not be available until after the conference. There is little current reference to technology or number in both the use of qualitative methods in social research and especially the teaching of qualitative methods, particularly at undergraduate level. The one exception to this is the discussion of the use of CAQDAS programs in several textbooks aimed at undergraduate users. However, there is no strong evidence that this translates into widespread use of the programs in undergraduate teaching in the UK. Indeed in a web-based survey of teachers of qualitative methods (Survey 2) that I carried out for a previous HEA funded project (REQUALLO) I found only 6% of departments that replied to the survey used CAQDAS at undergraduate level, although much higher proportions used it at postgraduate level. At the moment, at undergraduate level, there is a distinct inequality in software use between qualitative and quantitative research methods teaching. Almost all undergraduate courses on quantitative methods will, at some point, cover the use of statistics and will require students to use software (such as SPSS). There are two factors that might begin to challenge this comparatively low level of software usage in qualitative methods: the increasing use of CAQDAS in research and the growth of interest in mixed methods approaches. In the case of the former, there is evidence for a strong growth in the use of CAQDAS in social research. There is also a growth in the popularity of mixed methods designs, not only in the number of published papers using such an approach, but also in the number of PhD students undertaking such projects. To support this, in the last few years, many of the major publishers of CAQDAS programs have included functionality in their software that integrates quantitative data with the qualitative analysis. This includes a range of data mining, keyword in context searches and cluster analysis techniques as well as the ability to import quantitative case attribute data that can be used in the analysis. All this is integrated with the basic thematic coding system the software supports. There are, however, significant barriers to the increased use of number and software in undergraduate qualitative methods teaching. In Survey 1 I asked teachers why the software was not used at undergraduate level. Common reasons given included, no time (17%), lack of teachers’ skills in the software (13%), no funding for site licences or local support for software (12%) and most commonly, that it would take too long to teach (24%). However, significantly, given the antagonism of some qualitative researcher to software use, only 3% said that the software was not used in teaching because it does not support the methodology or the theoretical approach they used. This situation is changing. Many UK universities now hold site licences for the software (just as they do for statistical software). About a year ago, QSR, the publisher of the market leading NVivo software, told me that 74 UK universities held site licences and there are several who hold similar licence for competing programs. Nevertheless several barriers remain: 1. Lack of skills in both CAQDAS use and mixed methods amongst qualitative research methods teachers at undergraduate level. 2. There are few good exemplars, usable at undergraduate level, of how software and numeric skills can enhance qualitative analysis. 3. Lack of OERs suitable for undergraduate use that tackle this issue (but there are some QSR videos on this). This paper will report on the current state of skills teaching and of available resources with a focus on the U

Elastic Scattering of Pions From the Three-nucleon System

We examine the scattering of charged pions from the trinucleon system at a pion energy of 180 MeV. The motivation for this study is the structure seen in the experimental angular distribution of back-angle scattering for pi+ 3He and pi- 3H but for neither pi- 3He nor pi+ 3H. We consider the addition of a double spin flip term to an optical model treatment and find that, though the contribution of this term is non-negligible at large angles for pi+ 3He and pi- 3H, it does not reproduce the structure seen in the experiment.Comment: 15 pages + 5 figure