Promoting middle school students’ proportional reasoning skills through an ongoing professional development programme for teachers

© 2016, Springer Science+Business Media Dordrecht. Proportional reasoning, the ability to use ratios in situations involving comparison of quantities, is essential for mathematical competence, especially in the middle school years, and is an important determinant of success beyond school. Research shows students find proportional reasoning and its foundational concepts difficult. Proportional reasoning does not always develop naturally, however some research suggests that with targeted teaching, its development can be promoted. This paper reports on a large Australian study involving over 130 teachers and their students. A major goal of the study was to investigate the efficacy of ongoing teacher professional development for promoting middle years students’ proportional reasoning. A series of professional development workshops was designed to enhance the teachers’ understanding of proportional reasoning and to extend their repertoire of teaching strategies to promote their students’ proportional reasoning skills. The workshop design was informed by research literature on proportional reasoning teaching and learning as well as the results of a diagnostic instrument administered to over 2500 middle years students prior to the professional development. Between workshops, the teachers implemented a variety of targeted teaching activities. This paper reports on pre- and post- instrument student data collected at the beginning and end of the first year of the project (i.e., after completion of half of the workshops). The findings suggest that targeted professional development and explicit teaching can make a difference to students’ proportional reasoning

The analysis of reactively loaded microstrip antennas by finite difference time domain modelling

In recent years, much interest has been shown in the use of printed circuit antennas in mobile satellite and communications terminals at microwave frequencies. Although such antennas have many advantages in weight and profile size over more conventional reflector/horn configurations, they do, however, suffer from an inherently narrow bandwidth. A way of optimizing the bandwidth of such antennas by an electronic tuning technique using a loaded probe mounted within the antenna structure is examined, and the resulting far-field radiation patterns are shown. Simulation results from a 2D finite difference time domain (FDTD) model for a rectangular microstrip antenna loaded with shorting pins are given and compared to results obtained with an actual antenna. It is hoped that this work will result in a design package for the analysis of microstrip patch antenna elements

Standard-M mobile satellite terminal employing electronic beam squint tracking

In recent years, extensive experience has been built up at the University of Bristol in the use of the Electronic Beam Squint (EBS) tracking technique, applied to large earth station facilities. The current interest in land mobile satellite terminals, using small tracking antennas, has prompted the investigation of the applicability of the EBS technique to this environment. The development of an L-band mechanically steered vehicle antenna is presented. A description of the antenna is followed by a detailed investigation of the tracking environment and its implications on the error detection capability of the system. Finally, the overall hardware configuration is described along with plans for future work

Public views on the donation and use of human biological samples in biomedical research: a mixed methods study

Objective A mixed methods study exploring the UK general public's willingness to donate human biosamples (HBSs) for biomedical research.<p></p> Setting Cross-sectional focus groups followed by an online survey.<p></p> Participants Twelve focus groups (81 participants) selectively sampled to reflect a range of demographic groups; 1110 survey responders recruited through a stratified sampling method with quotas set on sex, age, geographical location, socioeconomic group and ethnicity.<p></p> Main outcome measures (1) Identify participants’ willingness to donate HBSs for biomedical research, (2) explore acceptability towards donating different types of HBSs in various settings and (3) explore preferences regarding use and access to HBSs.<p></p> Results 87% of survey participants thought donation of HBSs was important and 75% wanted to be asked to donate in general. Responders who self-reported having some or good knowledge of the medical research process were significantly more likely to want to donate (p<0.001). Reasons why focus group participants saw donation as important included: it was a good way of reciprocating for the medical treatment received; it was an important way of developing drugs and treatments; residual tissue would otherwise go to waste and they or their family members might benefit. The most controversial types of HBSs to donate included: brain post mortem (29% would donate), eyes post mortem (35%), embryos (44%), spare eggs (48%) and sperm (58%). Regarding the use of samples, there were concerns over animal research (34%), research conducted outside the UK (35%), and research conducted by pharmaceutical companies (56%), although education and discussion were found to alleviate such concerns.<p></p> Conclusions There is a high level of public support and willingness to donate HBSs for biomedical research. Underlying concerns exist regarding the use of certain types of HBSs and conditions under which they are used. Improved education and more controlled forms of consent for sensitive samples may mitigate such concerns.<p></p&gt

Consent for the use of human biological samples for biomedical research: a mixed methods study exploring the UK public’s preferences

OBJECTIVE: A mixed-methods study exploring the UK general public's views towards consent for the use of biosamples for biomedical research.<p></p> SETTING: Cross-sectional population-based focus groups followed by an online survey.<p></p> PARTICIPANTS: 12 focus groups (81 participants) selectively sampled to reflect a range of demographic groups; 1110 survey responders recruited through a stratified sampling method with quotas set on sex, age, geographical location, socioeconomic group and ethnicity.<p></p> MAIN OUTCOME MEASURES: (1) Views on the importance of consent when donating residual biosamples for medical research; (2) preferences for opt-in or opt-out consent approaches and (3) preferences for different consent models.<p></p> RESULTS: Participants believed obtaining consent for use of residual biosamples was important as it was 'morally correct' to ask, and enabled people to make an active choice and retain control over their biosamples. Survey responders preferred opt-in consent (55%); the strongest predictor was being from a low socioeconomic group (OR 2.22, 95% CI 1.41 to 3.57, p=0.001) and having a religious affiliation (OR 1.36, 95% CI 1.01 to 1.81, p=0.04). Focus group participants had a slight preference for opt-out consent because by using this approach more biosamples would be available and facilitate research. Concerning preferred models of consent for research use of biosamples, survey responders preferred specific consent with recontact for each study for which their biosamples are eligible. Focus group participants preferred generic consent as it provided 'flexibility for researchers' and reduced the likelihood that biosamples would be wasted. The strongest predictor for preferring specific consent was preferring opt-in consent (OR 4.58, 95% CI 3.30 to 6.35, p=0.015) followed by non-'White' ethnicity (OR 2.94, 95% CI 1.23 to 7.14, p<0.001).<p></p> CONCLUSIONS: There is a preference among the UK public for ongoing choice and control over donated biosamples; however, increased knowledge and opportunity for discussion is associated with acceptance of less restrictive consent models for some people.<p></p&gt

Reporting of MMR evidence in professional publications: 1988–2007

OBJECTIVE: To examine how journals and magazines disseminate research evidence and guidance on best practice to health professionals by aligning commentaries on measles, mumps, and rubella vaccine (MMR) evidence in journals with key events in the MMR controversy. DESIGN: Content analysis. DATA SOURCES: Comment articles in six commonly read UK publications. MAIN OUTCOME MEASURES: Number of comment pieces by publication, year and article type; trends in the focus, tone and inclusion of recommendations on MMR. RESULTS: 860 articles met the inclusion criteria (BMJ n = 104, Community Practitioner n = 45, Health Visitor n = 24, Practice Nurse n = 61, Nursing Standard n = 61 and Pulse n = 565). Of these 860 comment pieces, 264 made some reference to evidence endorsing the safety of MMR. Around one in 10 were rated as negative (10.9%, n = 29) or neutral (11.3%, n = 30) in relation to MMR safety, and nearly a quarter (22.7%, n = 60) were rated as mixed. Following the publication of Wakefield et al's 1998 paper there was a period of neutrality. In 2000, despite growing public concerns and widespread media coverage, fewer than 20 comment pieces were published. Less than a quarter of comment pieces (n = 196, 22.7%) included recommendations. CONCLUSION: While a period of neutrality may reflect a professional response to uncertainty by holding back until consensus emerges, it may also represent a missed opportunity to promote evidence-based practice

White Light Flare Continuum Observations with ULTRACAM

We present sub-second, continuous-coverage photometry of three flares on the dM3.5e star, EQ Peg A, using custom continuum filters with WHT/ULTRACAM. These data provide a new view of flare continuum emission, with each flare exhibiting a very distinct light curve morphology. The spectral shape of flare emission for the two large-amplitude flares is compared with synthetic ULTRACAM measurements taken from the spectra during the large 'megaflare' event on a similar type flare star. The white light shape during the impulsive phase of the EQ Peg flares is consistent with the range of colors derived from the megaflare continuum, which is known to contain a Hydrogen recombination component and compact, blackbody-like components. Tentative evidence in the ULTRACAM photometry is found for an anti-correlation between the emission of these components.Comment: 8 pages, 3 figures. Proceedings of the 16th Workshop on Cool Stars, Stellar Systems, and the Sun (PASP conference series, in press

Pure dephasing in flux qubits due to flux noise with spectral density scaling as 1/fα1/ f^\alpha

For many types of superconducting qubits, magnetic flux noise is a source of pure dephasing. Measurements on a representative dc superconducting quantum interference device (SQUID) over a range of temperatures show that $S_\Phi(f) = A^2/(f/1 \hbox{Hz})^\alpha$, where $S_\Phi$ is the flux noise spectral density, $A$ is of the order of 1 $\mu\Phi_0 \, \hbox{Hz}^{-1/2}$ and $0.61 \leq \alpha \leq 0.95$; $\Phi_{0}$ is the flux quantum. For a qubit with an energy level splitting linearly coupled to the applied flux, calculations of the dependence of the pure dephasing time $\tau_\phi$ of Ramsey and echo pulse sequences on $\alpha$ for fixed $A$ show that $\tau_\phi$ decreases rapidly as $\alpha$ is reduced. We find that $\tau_\phi$ is relatively insensitive to the noise bandwidth, $f_1 \leq f \leq f_2$, for all $\alpha$ provided the ultraviolet cutoff frequency $f_2 > 1/\tau_\phi$. We calculate the ratio $\tau_{\phi,E} / \tau_{\phi,R}$ of the echo ($E$) and Ramsey ($R$) sequences, and the dependence of the decay function on $\alpha$ and $f_2$. We investigate the case in which $S_\Phi(f_0)$ is fixed at the "pivot frequency" $f_0 \neq 1$ Hz while $\alpha$ is varied, and find that the choice of $f_0$ can greatly influence the sensitivity of $\tau_{\phi,E}$ and $\tau_{\phi,R}$ to the value of $\alpha$. Finally, we present calculated values of $\tau_\phi$ in a qubit corresponding to the values of $A$ and $\alpha$ measured in our SQUID.Comment: 7 pages, 8 figures, 1 tabl

MeerKAT's View of the Bullet Cluster 1E 0657-55.8

The Bullet cluster (1E 0657-55.8) is a massive merging system at redshift $z$=0.296, known to host a powerful radio halo and a relic. Here we present high fidelity MeerKAT L-band (0.9-1.7 GHz) observations of the Bullet cluster, in which we trace a larger extent of both the radio halo and relic in comparison to previous studies. The size of the recovered radio halo is 1.6 Mpc $\times$ 1.3 Mpc and the largest linear size of the relic is ~988 kpc. We detect a new decrement feature on the southern outskirts of the halo emission, where a region appears to have a lower surface brightness in comparison to its surroundings. The fainter extension on the outskirts of the radio halo suggests a new wave of merger activity. An in-band spectral index map of the radio halo reveals a hint of radial steepening towards the edges of the diffuse source, likely due to synchrotron electron ageing. The integrated spectral index of the radio halo is 1.1$\pm$0.2. We perform a radio-X-ray surface brightness point-to-point analysis, which reveals a linear correlation for the radio halo. This indicates that the radio halo emission is produced by primary re-acceleration mechanisms. Finally, we derive a radio Mach number of M_R= 4.6$\pm$0.9 for the relic shock region, which is higher than the Mach number inferred by earlier analyses based on X-ray data. Discrepancies between radio and X-ray Mach numbers have been observed for multiple systems, with studies suggesting that this is due to various factors, including relic orientation.Comment: 11 pages, 6 figures. Submitted to MNRAS; corrected typo in the Mach numbe