62,656 research outputs found
Human serum albumin crystals and method of preparation
Human serum albumin (HSA) crystals are provided in the form of tetragonal plates having the space groups P42(sub 1)2, the crystals being grown to sizes in excess of 0.5 mm in two dimensions and a thickness of 0.1 mm. Growth of the crystals is carried out by a hanging drop method wherein a precipitant solution containing polyethylene glycol (PEG) and a phosphate buffer is mixed with an HSA solution, and a droplet of mixed solution is suspended over a well of precipitant solution. Crystals grow to the desired size in 3 to 7 days. Concentration of reagents, pH and other parameters are controlled within prescribed limits. The resulting crystals exhibit a size and quality such as to allow performance of x ray diffraction studies and enable the conduct of drug binding studies as well as genetic engineering studies
First Line of Defense: Protecting Youth on Campus
Many institutions recognize the need for a centralized process to address the safety of youth on campus. Legislation, publicized incidents, state and national laws, and research have pushed this topic to the forefront. In an effort to educate, mitigate risk, and create consistency, the implementation of university-wide youth protection policies has become a common practice. While each campus is different, foundational components to these policies can create a cultural shift and educate individuals on their role in reporting abuse and neglect. Virginia Commonwealth University (VCU) launched its youth protection policy, Safety and Protection of Minors, in July 2016. The policy took over two years to create and is now in the second year of implementation. Based on the evolution of this policy, from inception to application, the university has learned that this initiative is a shared responsibility and that leaders play a key role
Contractor Drilling with Pounder II
Project Manager Dr Richard Carter, Institute of Water and Environment, Cranfield University at Silsoe.This report contributes to the findings, implications, and future plans of a project,
initiated by Cranfield University (Silsoe, UK) entitled “Private Sector Participation in Low
Cost Water Well Drilling”.The project was funded by DFID from July 1998 to June
2001, with additional funding partners (Government of Uganda, DANIDA, SIDA,
UNICEF, Water Aid, and an anonymous donor) joining at various stages throughout this
three-year period
Chaotic string-capture by black hole
We consider a macroscopic charge-current carrying (cosmic) string in the
background of a Schwarzschild black hole. The string is taken to be circular
and is allowed to oscillate and to propagate in the direction perpendicular to
its plane (that is parallel to the equatorial plane of the black hole).
Nurmerical investigations indicate that the system is non-integrable, but the
interaction with the gravitational field of the black hole anyway gives rise to
various qualitatively simple processes like "adiabatic capture" and "string
transmutation".Comment: 13 pages Latex + 3 figures (not included), Nordita 93/55
Geographical co-location, social networks and inter-firm marketing co-operation : the case of the salmon industry
This study looks at the factors that influence the development of marketing co-operation among cluster-based firms. It examines data from SMEs operating within the salmon farming industry in two different regions: Scotland and Chile. Analyses indicate that informal social networks help explain the observed relationship between geographical proximity and inter-firm marketing co-operation, especially for firms located in peripheral rural communities. A theoretical model is proposed for further research in the field that, until recently, has been traditionally analysed only by economists. Practical implications are suggested for practitioners and policymaker
Small-angle scattering in a marginal Fermi-liquid
We study the magnetotransport properties of a model of small-angle scattering
in a marginal Fermi liquid. Such a model has been proposed by Varma and
Abrahams [Phys. Rev. Lett. 86, 4652 (2001)] to account for the anomalous
temperature dependence of in-plane magnetotransport properties of the high-Tc
cuprates. We study the resistivity, Hall angle and magnetoresistance using both
analytical and numerical techniques. We find that small-angle scattering only
generates a new temperature dependence for the Hall angle near particle-hole
symmetric Fermi surfaces where the conventional Hall term vanishes. The
magnetoresistance always shows Kohler's rule behavior.Comment: 4 pages, 3 figures, Revtex
An empirical analysis of the distribution of the duration of overshoots in a stationary gaussian stochastic process
This analysis utilizes computer simulation and statistical estimation. Realizations of stationary gaussian stochastic processes with selected autocorrelation functions are computer simulated. Analysis of the simulated data revealed that the mean and the variance of a process were functionally dependent upon the autocorrelation parameter and crossing level. Using predicted values for the mean and standard deviation, by the method of moments, the distribution parameters was estimated. Thus, given the autocorrelation parameter, crossing level, mean, and standard deviation of a process, the probability of exceeding the crossing level for a particular length of time was calculated
Poly-essential and general Hyperelastic World (brane) models
This article provides a unified treatment of an extensive category of
non-linear classical field models whereby the universe is represented (perhaps
as a brane in a higher dimensional background) in terms of a structure of a
mathematically convenient type describable as hyperelastic, for which a
complete set of equations of motion is provided just by the energy-momentum
conservation law. Particular cases include those of a perfect fluid in
quintessential backgrounds of various kinds, as well as models of the elastic
solid kind that has been proposed to account for cosmic acceleration. It is
shown how an appropriately generalised Hadamard operator can be used to
construct a symplectic structure that controles the evolution of small
perturbations, and that provides a characteristic equation governing the
propagation of weak discontinuities of diverse (extrinsic and extrinsic) kinds.
The special case of a poly-essential model - the k-essential analogue of an
ordinary polytropic fluid - is examined and shown to be well behaved (like the
fluid) only if the pressure to density ratio is positive.Comment: 16 pages Latex, Contrib. to 10th Peyresq Pysics Meeting, June 2005:
Micro and Macro Structures of Spacetim
Quantum integrability of quadratic Killing tensors
Quantum integrability of classical integrable systems given by quadratic
Killing tensors on curved configuration spaces is investigated. It is proven
that, using a "minimal" quantization scheme, quantum integrability is insured
for a large class of classic examples.Comment: LaTeX 2e, no figure, 35 p., references added, minor modifications. To
appear in the J. Math. Phy
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