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Neuroinflammation is a putative target for the prevention and treatment of perioperative neurocognitive disorders.
IntroductionThe demographics of aging of the surgical population has increased the risk for perioperative neurocognitive disorders in which trauma-induced neuroinflammation plays a pivotal role.Sources of dataAfter determining the scope of the review, the authors used PubMed with select phrases encompassing the words in the scope. Both preclinical and clinical reports were considered.Areas of agreementNeuroinflammation is a sine qua non for development of perioperative neurocognitive disorders.Areas of controversyWhat is the best method for ameliorating trauma-induced neuroinflammation while preserving inflammation-based wound healing.Growing pointsThis review considers how to prepare for and manage the vulnerable elderly surgical patient through the entire spectrum, from preoperative assessment to postoperative period.Areas timely for developing researchWhat are the most effective and safest interventions for preventing and/or reversing Perioperative Neurocognitive Disorders
Electron spin decoherence of single Nitrogen-Vacancy defects in diamond
We present a theoretical analysis of the electron spin decoherence in single
Nitrogen-Vacancy defects in ultra-pure diamond. The electron spin decoherence
is due to the interactions with Carbon-13 nuclear spins in the diamond lattice.
Our approach takes advantage of the low concentration (1.1%) of Carbon-13 and
their random distribution in the diamond lattice by an algorithmic aggregation
of spins into small, strongly interacting groups. By making use of this
\emph{disjoint cluster} approach, we demonstrate a possibility of non-trival
dynamics of the electron spin that can not be described by a single time
constant. This dependance is caused by a strong coupling between the electron
and few nuclei and results, in particular, in a substantial echo signal even at
microsecond time scales. Our results are in good agreement with recent
experimental observations
Defining Agency and Its Scope (II)
Fiduciary law necessarily raises issues of delineation and demarcation, which this paper demonstrates through examples involving common-law agents. Serving as an agent, and thus as a fiduciary, does not necessarily mean that agency law prescribes all duties that the agent owes the principal. The agent may have rights external to the relationship that the agent may exercise, distinct from the duty of loyalty owed the principal. When an agent acts outside the bounds of an agency relationship, the principal’s consent is not requisite to conduct that would constitute disloyalty within the bounds of the agency relationship. The paper illustrates the significance of this point through a series of examples drawn from a range of contexts, including auctions of art objects. Prior scholarship neglects the implications of demarcations that define the scope of an agency relationship and of fiduciary relationships more generically.
More generally or theoretically, the paper examines the qualities of fiduciary duty as a default rule, arguing that the relative “stickiness” of the default varies. Agency law contains two different kinds of altering rules—necessary and sufficient conditions to vary a default rule—consisting of agreements that define the scope of the agent’s representative role on behalf of the principal, and consent by the principal to actions by the agent within that scope that relieve the agent of liability for breach of fiduciary duty, which impose significantly different requisites. The basic distinction between agreement and consent has parallels elsewhere in agency law; for example, ratification, like consent, requires specificity because to be legally effective ratification requires that the principal know, as a matter of historical fact, what the agent has done. Agreement, on the other hand, requires less specificity, comparable to manifestations that confer actual authority on an agent which necessarily does not require that the principal foresee all actions that the agent may take that fall within the scope of the grant of authority. And ratification, like effective consent, is a matter of historical fact, not hypothesis. These implications follow because agency law, by positioning an agent as the principal’s representative for purposes of legally-salient interactions with third parties and facts about the world, frames the agent as an extension of the principal, not the principal’s substitute
Coherent Population Trapping with a controlled dissipation: applications in optical metrology
We analyze the properties of a pulsed Coherent Population Trapping protocol
that uses a controlled decay from the excited state in a -level
scheme. We study this problem analytically and numerically and find regimes
where narrow transmission, absorption, or fluorescence spectral lines occur. We
then look for optimal frequency measurements using these spectral features by
computing the Allan deviation in the presence of ground state decoherence and
show that the protocol is on a par with Ramsey-CPT. We discuss possible
implementations with ensembles of alkali atoms and single ions and demonstrate
that typical pulsed-CPT experiments that are realized on femto-second
time-scales can be implemented on micro-seconds time-scales using this scheme.Comment: 9 pages, 7 figure
Strong magnetic coupling between an electronic spin qubit and a mechanical resonator
We describe a technique that enables a strong, coherent coupling between a
single electronic spin qubit associated with a nitrogen-vacancy impurity in
diamond and the quantized motion of a magnetized nano-mechanical resonator tip.
This coupling is achieved via careful preparation of dressed spin states which
are highly sensitive to the motion of the resonator but insensitive to
perturbations from the nuclear spin bath. In combination with optical pumping
techniques, the coherent exchange between spin and motional excitations enables
ground state cooling and the controlled generation of arbitrary quantum
superpositions of resonator states. Optical spin readout techniques provide a
general measurement toolbox for the resonator with quantum limited precision
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