3,837 research outputs found
Comprehensive characterization of molecular interactions based on nanomechanics
Molecular interaction is a key concept in our understanding of the biological mechanisms of life. Two physical properties change when one molecular partner binds to another. Firstly, the masses combine and secondly, the structure of at least one binding partner is altered, mechanically transducing the binding into subsequent biological reactions. Here we present a nanomechanical micro-array technique for bio-medical research, which not only monitors the binding of effector molecules to their target but also the subsequent effect on a biological system in vitro. This label-free and real-time method directly and simultaneously tracks mass and nanomechanical changes at the sensor interface using micro-cantilever technology. To prove the concept we measured lipid vesicle (approximately 748*10(6) Da) adsorption on the sensor interface followed by subsequent binding of the bee venom peptide melittin (2840 Da) to the vesicles. The results show the high dynamic range of the instrument and that measuring the mass and structural changes simultaneously allow a comprehensive discussion of molecular interactions
REFERQUAL: A pilot study of a new service quality assessment instrument in the GP Exercise Referral scheme setting
Background
The development of an instrument accurately assessing service quality in the GP Exercise Referral Scheme (ERS) industry could potentially inform scheme organisers of the factors that affect adherence rates leading to the implementation of strategic interventions aimed at reducing client drop-out.
Methods
A modified version of the SERVQUAL instrument was designed for use in the ERS setting and subsequently piloted amongst 27 ERS clients.
Results
Test re-test correlations were calculated via Pearson's 'r' or Spearman's 'rho', depending on whether the variables were Normally Distributed, to show a significant (mean r = 0.957, SD = 0.02, p < 0.05; mean rho = 0.934, SD = 0.03, p < 0.05) relationship between all items within the questionnaire. In addition, satisfactory internal consistency was demonstrated via Cronbach's 'α'. Furthermore, clients responded favourably towards the usability, wording and applicability of the instrument's items.
Conclusion
REFERQUAL is considered to represent promise as a suitable tool for future evaluation of service quality within the ERS community. Future research should further assess the validity and reliability of this instrument through the use of a confirmatory factor analysis to scrutinise the proposed dimensional structure
On Symmetries of Extremal Black Holes with One and Two Centers
After a brief introduction to the Attractor Mechanism, we review the
appearance of groups of type E7 as generalized electric-magnetic duality
symmetries in locally supersymmetric theories of gravity, with particular
emphasis on the symplectic structure of fluxes in the background of extremal
black hole solutions, with one or two centers. In the latter case, the role of
an "horizontal" symmetry SL(2,R) is elucidated by presenting a set of
two-centered relations governing the structure of two-centered invariant
polynomials.Comment: 1+13 pages, 2 Tables. Based on Lectures given by SF and AM at the
School "Black Objects in Supergravity" (BOSS 2011), INFN - LNF, Rome, Italy,
May 9-13 201
A survey of attitudes toward clinical research among physicians at Kyoto University Hospital
<p>Abstract</p> <p>Background</p> <p>In Japan, only clinical research related to investigational new drug trials must be notified to regulatory bodies, and this lack of a uniform standard for clinical research has caused a number of difficulties. The objective of this study was to assess the willingness of physicians to participate in clinical research and to identify effective methods to promote and enhance clinical research.</p> <p>Methods</p> <p>We conducted a cross-sectional survey by administrating questionnaires to physicians in 31 departments in Kyoto University Hospital from October through November 2007.</p> <p>Results</p> <p>A total of 51.5% (310 of 602) of physicians completed the questionnaire. More than two-thirds of them reported currently participating in clinical research, and nearly all believed that clinical research is necessary for physicians. Less than 20% of respondents had specific training regarding clinical research, and most reported a need to acquire concepts and skills regarding clinical research, especially those related to statistics. "Paperwork was complicated and onerous" was the most frequently cited obstacle in conducting clinical research, followed by "few eligible patients" and "lack of time". Previous participation in and prospective participation in clinical research, previous writing a research protocol were positively associated with current participation in clinical research.</p> <p>Conclusions</p> <p>Physicians in university hospitals need more training regarding clinical research, particularly in biostatistics. They also require administrative assistance. Our findings indicate that the quality of clinical research could be improved if training in clinical research methodology and biostatistics were provided, and if greater assistance in the preparation of study documents requested by the institutional Independent Ethics Committee were available.</p
Animal or Plant: Which Is the Better Fog Water Collector?
Occasional fog is a critical water source utilised by plants and animals in the Namib Desert. Fog basking beetles (Onymacris unguicularis, Tenebrionidae) and Namib dune bushman grass (Stipagrostris sabulicola, Poaceae) collect water directly from the fog. While the beetles position themselves optimally for fog water collection on dune ridges, the grass occurs predominantly at the dune base where less fog water is available. Differences in the fog-water collecting abilities in animals and plants have never been addressed. Here we place beetles and grass side-by-side in a fog chamber and measure the amount of water they collect over time. Based on the accumulated amount of water over a two hour period, grass is the better fog collector. However, in contrast to the episodic cascading water run-off from the grass, the beetles obtain water in a steady flow from their elytra. This steady trickle from the beetles' elytra to their mouth could ensure that even short periods of fog basking – while exposed to predators – will yield water. Up to now there is no indication of specialised surface properties on the grass leafs, but the steady run-off from the beetles could point to specific property adaptations of their elytra surface
Entanglement generation outside a Schwarzschild black hole and the Hawking effect
We examine the Hawking effect by studying the asymptotic entanglement of two
mutually independent two-level atoms placed at a fixed radial distance outside
a Schwarzschild black hole in the framework of open quantum systems. We treat
the two-atom system as an open quantum system in a bath of fluctuating
quantized massless scalar fields in vacuum and calculate the concurrence, a
measurement of entanglement, of the equilibrium state of the system at large
times, for the Unruh, Hartle-Hawking and Boulware vacua respectively. We find,
for all three vacuum cases, that the atoms turn out to be entangled even if
they are initially in a separable state as long as the system is not placed
right at the even horizon. Remarkably, only in the Unruh vacuum, will the
asymptotic entanglement be affected by the backscattering of the thermal
radiation off the space-time curvature. The effect of the back scatterings on
the asymptotic entanglement cancels in the Hartle-Hawking vacuum case.Comment: 15 pages, no figures, Revte
Conformally rescaled spacetimes and Hawking radiation
We study various derivations of Hawking radiation in conformally rescaled
metrics. We focus on two important properties, the location of the horizon
under a conformal transformation and its associated temperature. We find that
the production of Hawking radiation cannot be associated in all cases to the
trapping horizon because its location is not invariant under a conformal
transformation. We also find evidence that the temperature of the Hawking
radiation should transform simply under a conformal transformation, being
invariant for asymptotic observers in the limit that the conformal
transformation factor is unity at their location.Comment: 22 pages, version submitted to journa
- …