1,198 research outputs found
Magnetic field independence of the spin gap in YBa_2Cu_3O_{7-delta}
We report, for magnetic fields of 0, 8.8, and 14.8 Tesla, measurements of the
temperature dependent ^{63}Cu NMR spin lattice relaxation rate for near
optimally doped YBa_2Cu_3O_{7-delta}, near and above T_c. In sharp contrast
with previous work we find no magnetic field dependence. We discuss
experimental issues arising in measurements of this required precision, and
implications of the experiment regarding issues including the spin or pseudo
gap.Comment: 4 pages, 3 figures, as accepted for publication in Physical Review
Letter
The illusion of competency versus the desirability of expertise: Seeking a common standard for support professions in sport
In this paper we examine and challenge the competency-based models which currently dominate accreditation and development systems in sport support disciplines, largely the sciences and coaching. Through consideration of exemplar shortcomings, the limitations of competency-based systems are presented as failing to cater for the complexity of decision making and the need for proactive experimentation essential to effective practice. To provide a better fit with the challenges of the various disciplines in their work with performers, an alternative approach is presented which focuses on the promotion, evaluation and elaboration of expertise. Such an approach resonates with important characteristics of professions, whilst also providing for the essential âshades of greyâ inherent in work with human participants. Key differences between the approaches are considered through exemplars of evaluation processes. The expertise-focused method, although inherently more complex, is seen as offering a less ambiguous and more positive route, both through more accurate representation of essential professional competence and through facilitation of future growth in proficiency and evolution of expertise in practice. Examples from the literature are also presented, offering further support for the practicalities of this approach
Capabilities of a lobster eye telescope in the outer solar system
Current lobster eye telescopes demonstrate that itâs possible to produce light-weight, large field of view instruments for observing X-rays for both planetary science and astronomy. Jupiter is the most powerful particle accelerator in the solar system and the other outer planets have intricate and complicated magnetospheres which their moons often orbit within. Particle bombardment of the surfaces of their moons induces the emission of characteristic X-rays which enables their composition to be studied. An orbiting X-ray instrument would transform our understanding of the moonsâ composition, as well as the aurorae, atmosphere, plasma tori of outer planet systems and could also enable direct imaging of the entire radiation belt. Lobster eye telescopes are perfect for this application due to their light weight and wide field of view. This paper begins to identify a lobster eye telescope design to fulfil these science goals
Blaming Bill Gates AGAIN! Misuse, overuse and misunderstanding of performance data in sport
Recently in Sport, Education and Society, Williams and Manley (2014) argued against the heavy reliance on technology in professional Rugby Union and elite sport in general. In summary, technology is presented as an elitist, âgold standardâ villain that management and coaches use to exert control and by which players lose autonomy, identity, motivation, social interactions and expertise. In this article we suggest that the sociological interpretations and implications offered by Williams and Manley may be somewhat limited when viewed in isolation. In doing so, we identify some core methodological issues in Williams and Manleyâs study and critically consider important arguments for utilising technology; notably, to inform coach decision making and generate player empowerment. Secondly, we present a different, yet perhaps equally concerning, practice-oriented interpretation of the same results but from alternative coaching and expertise literature. Accordingly, we suggest that Williams and Manley have perhaps raised their alarm prematurely, inappropriately and on somewhat shaky foundations. We also hope to stimulate others to consider contrary positions, or at least to think about this topic in greater detail. More specifically, we encourage coaches and academics to think carefully about what technology is employed, how and why, and then the means by which these decisions are discussed with and, preferably, sold to players. Certainly, technology can significantly enhance coach decision making and practice, while also helping players to optimise their focus, empowerment and independence in knowing how to achieve their personal and collective goals
Molecular orientational dynamics of the endohedral fullerene ScN@C as probed by C and Sc NMR
We measure 13C and 45Sc NMR lineshapes and spin-lattice relaxation times (T1)
to probe the orientational dynamics of the endohedral metallofullerene
Sc3N@C80. The measurements show an activated behavior for molecular
reorientations over the full temperature range with a similar behavior for the
temperature dependence of the 13C and 45Sc data. Combined with spectral data
from Magic Angle Spinning (MAS) NMR, the measurements can be interpreted to
mean the motion of the encapsulated Sc3N molecule is independent of that of the
C80 cage, although this requires the similar temperature dependence of the 13C
and 45Sc spin-lattice relaxation times to be coincidental. For the Sc3N to be
fixed to the C80 cage, one must overcome the symmetry breaking effect this has
on the Sc3N@C80 system since this would result in more than the observed two
13C lines.Comment: 6 pages, 5 figure
Multiparameter analysis of vasculature, perfusion and proliferation in human tumour xenografts.
A method is presented in this report for concurrent analysis of vascular architecture, blood perfusion and proliferation characteristics in whole-tumour cross-sections of human larynx carcinoma and glioblastoma xenografts. Tumours were implanted subcutaneously in nude mice. After i.v. injection with Hoechst 33342 and bromodeoxyuridine (BrdUrd) as perfusion and proliferation markers, animals were killed. An antiendothelial antibody (9F1) was used to delineate vascular structures. Cross-sections were analysed by a multistep immune staining and a computer-controlled microscope scanning method. Each tumour section was stained and scanned four times (Hoechst, 9F1, BrdUrd and Fast Blue for all nuclei). When these images were combined, vasculature, perfusion and proliferation parameters were analysed. The labelling index (LI) was defined as the ratio of the BrdUrd-labelled area to the total nuclear area. The LI based on manual counting and the LI calculated by flow cytometry (FCM) were in good agreement with the LI based on surface analysis. LI decreased at increasing distance from its nearest vessel. In the vicinity of perfused vessels, the LI was 30-70% higher than near non-perfused vessels. This method shows that both vasculature/perfusion and proliferation characteristics can be measured in the same whole-tumour section in a semiautomatic way. This could be applied in clinical practice to identify combined human tumour characteristics that predict for a favourable response to treatment modifications
Transistor and Diode Studies
Contains reports on four research projects.Lincoln Laboratory (Purchase Order DDL-B187)United States Department of the ArmyUnited States Department of the NavyUnited States Department of the Air Force (Contract AF19(122)-458
âEnriching Lives within Sedimentary Geologyâ: Actionable Recommendations for Making SEPM a Diverse, Equitable and Inclusive Society for All Sedimentary Geologists
Innovative science benefits from diversity of thought and influence at all waypoints along the scientific journey, from early education to career-length contributions in research and mentorship. Scientific societies, like the Society for Sedimentary Geology (SEPM), steward their innovators and the direction of the science, thereby defining the societal impact and evolution of a discipline. They are uniquely positioned to promote the representation and success of all scientists, including those from minoritized populations, through proactive advocacy, and inclusive mentorship, awards, and leadership. We introspectively review available records of SEPM membership, leadership, awardees, and editorial boards to identify areas for growth and begin a dialogue about how the society and its members can work together to better reflect our community. In the last decade, SEPM has seen a decline in membership, while representation and recognition of scientists from minoritized groups has remained low. Awards and honors have overwhelmingly gone to men, even in the last ten years, and very few women or people of color are in leadership roles. SEPM has recently taken positive steps towards becoming more inclusive (e.g., the Code of Professional Conduct); however, much more work is needed. We provide recommendations for swift actions that SEPM and its members should undertake for the society to become a diverse, inclusive, and equitable environment where all scientists thrive. The systemic changes needed will take continuous effort, which must be shared by all of us, to build an enduring legacy that we can be proud of
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