422 research outputs found
Learning about research by doing research: developing student researchers
In this article senior lecturers and second year students from the BA (Hons) Primary Education programme at Bishop Grosseteste University, who were involved in an educational research project, reflect on the importance of teacher led research and the impact on students of leading their own research projects. Teachersâ involvement with knowledge creation is widely recognised as an effective form of professional development (Hopkins, 2014; Taber, 2013). There has also been an increasingly prevalent binary view of Initial Teacher Education in which the real practical learning goes on in school placements whilst more theoretical learning goes on in universities (Czerniawski, 2018). However, student teacher research involving children should be seen as a consolidation of theory and practice. It is therefore essential that student teachers learn how to carry out research involving children, understand the ethical implications of this and recognise the value of reflecting on the effectiveness of pedagogical approaches. However, undertaking this kind of practitioner research can be daunting. Over the period of six weeks, the students were coached in research methods, data collection, analysis of data and drawing conclusions. Children from partnership schools visited the university to take part in the research tasks. This gave the students a valuable insight to key aspects of teaching and learning such as the childrenâs reading preferences, the use of digital resources to teach science and using story to support mathematical understanding. Studentsâ findings were presented in the form of research posters. Students found the project an interesting way to develop their understanding of research and reflected positively about what they had learnt about research methods
Method and apparatus for non-invasive evaluation of diaphragmatic function
A method for non-invasive evaluation of diaphragmatic function in humans measures the thickness of the diaphragm in real time with an ultrasonic device, and displays the variations of diaphragm thickness versus time. Formulae are given for calculating a quantitative value for the reserve fatigue capacity of a patient's diaphragm from data obtained by measuring the time limits for maintaining a constant breathing pattern on the display at two different pressure differentials in series with the patient's airways. An apparatus for displaying the diaphragm thickness in real time is also described. The method can be used both on healthy patients and on patients with so severe breathing dysfunctions that they require breathing support from respirators
An asymptotic form of the reciprocity theorem with applications in x-ray scattering
The emission of electromagnetic waves from a source within or near a
non-trivial medium (with or without boundaries, crystalline or amorphous, with
inhomogeneities, absorption and so on) is sometimes studied using the
reciprocity principle. This is a variation of the method of Green's functions.
If one is only interested in the asymptotic radiation fields the generality of
these methods may actually be a shortcoming: obtaining expressions valid for
the uninteresting near fields is not just a wasted effort but may be
prohibitively difficult. In this work we obtain a modified form the reciprocity
principle which gives the asymptotic radiation field directly. The method may
be used to obtain the radiation from a prescribed source, and also to study
scattering problems. To illustrate the power of the method we study a few
pedagogical examples and then, as a more challenging application we tackle two
related problems. We calculate the specular reflection of x rays by a rough
surface and by a smoothly graded surface taking polarization effects into
account. In conventional treatments of reflection x rays are treated as scalar
waves, polarization effects are neglected. This is a good approximation at
grazing incidence but becomes increasingly questionable for soft x rays and UV
at higher incidence angles.
PACs: 61.10.Dp, 61.10.Kw, 03.50.DeComment: 19 pages, 4 figure
Antiandrogens Act as Selective Androgen Receptor Modulators at the Proteome Level in Prostate Cancer Cells*
Current therapies for prostate cancer include antiandrogens, inhibitory ligands of the androgen receptor, which repress androgen-stimulated growth. These include the selective androgen receptor modulators cyproterone acetate and hydroxyflutamide and the complete antagonist bicalutamide. Their activity is partly dictated by the presence of androgen receptor mutations, which are commonly detected in patients who relapse while receiving antiandrogens, i.e. in castrate-resistant prostate cancer. To characterize the early proteomic response to these antiandrogens we used the LNCaP prostate cancer cell line, which harbors the androgen receptor mutation most commonly detected in castrate-resistant tumors (T877A), analyzing alterations in the proteome, and comparing these to the effect of these therapeutics upon androgen receptor activity and cell proliferation. The majority are regulated post-transcriptionally, possibly via nongenomic androgen receptor signaling. Differences detected between the exposure groups demonstrate subtle changes in the biological response to each specific ligand, suggesting a spectrum of agonistic and antagonistic effects dependent on the ligand used. Analysis of the crystal structures of the AR in the presence of cyproterone acetate, hydroxyflutamide, and DHT identified important differences in the orientation of key residues located in the AF-2 and BF-3 protein interaction surfaces. This further implies that although there is commonality in the growth responses between androgens and those antiandrogens that stimulate growth in the presence of a mutation, there may also be influential differences in the growth pathways stimulated by the different ligands. This therefore has implications for prostate cancer treatment because tumors may respond differently dependent upon which mutation is present and which ligand is activating growth, also for the design of selective androgen receptor modulators, which aim to elicit differential proteomic responses dependent upon cellular context
Improved Measurement of the Positive Muon Lifetime and Determination of the Fermi Constant
The mean life of the positive muon has been measured to a precision of 11 ppm
using a low-energy, pulsed muon beam stopped in a ferromagnetic target, which
was surrounded by a scintillator detector array. The result, tau_mu =
2.197013(24) us, is in excellent agreement with the previous world average. The
new world average tau_mu = 2.197019(21) us determines the Fermi constant G_F =
1.166371(6) x 10^-5 GeV^-2 (5 ppm). Additionally, the precision measurement of
the positive muon lifetime is needed to determine the nucleon pseudoscalar
coupling g_P.Comment: As published version (PRL, July 2007
Quiet daytime Arctic ionospheric D region
Phase and amplitude measurements of VLF radio waves propagating subâionospherically on long paths across the Arctic are used to determine the high latitude, daytime D region height and sharpness of the bottom edge of the Earth's ionosphere. The principal path used is from the 23.4 kHz transmitter, DHO, in north Germany, northwards across the Arctic passing ~2° from the North Pole, and then southwards to Nome, Alaska, thus avoiding most land and all thick ice. Significant observational support is obtained from the also nearly allâsea path from JXN in Norway (~67° N, 16.4 kHz) across the North Pole to Nome. By suitably comparing measurements with modeling using the US Navy code LWPC, the daytime D region (Wait) height and sharpness parameters in the Arctic are found to be H' = 73.7 ± 0.7 km and Ă = 0.32 ±0.02 kmâ1 in the summer of 2013 â i.e., at (weak) solar maximum. It is also found that, unlike at lower latitudes, VLF phase and amplitude recordings on (~1000 km) paths at high subarctic latitudes show very little change with solar zenith angle in both phase and amplitude during daytime for solar zenith angles ~300 keV for electrons) with a contribution from galactic cosmic rays, rather than by solar Lymanâα which dominates at low and middle latitudes
Revival of the magnetar PSR J1622-4950: observations with MeerKAT, Parkes, XMM-Newton, Swift, Chandra, and NuSTAR
New radio (MeerKAT and Parkes) and X-ray (XMM-Newton, Swift, Chandra, and
NuSTAR) observations of PSR J1622-4950 indicate that the magnetar, in a
quiescent state since at least early 2015, reactivated between 2017 March 19
and April 5. The radio flux density, while variable, is approximately 100x
larger than during its dormant state. The X-ray flux one month after
reactivation was at least 800x larger than during quiescence, and has been
decaying exponentially on a 111+/-19 day timescale. This high-flux state,
together with a radio-derived rotational ephemeris, enabled for the first time
the detection of X-ray pulsations for this magnetar. At 5%, the 0.3-6 keV
pulsed fraction is comparable to the smallest observed for magnetars. The
overall pulsar geometry inferred from polarized radio emission appears to be
broadly consistent with that determined 6-8 years earlier. However, rotating
vector model fits suggest that we are now seeing radio emission from a
different location in the magnetosphere than previously. This indicates a novel
way in which radio emission from magnetars can differ from that of ordinary
pulsars. The torque on the neutron star is varying rapidly and unsteadily, as
is common for magnetars following outburst, having changed by a factor of 7
within six months of reactivation.Comment: Published in ApJ (2018 April 5); 13 pages, 4 figure
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