2 resultados para Acyl-NHC Osmium Cooperative System
em Duke University
Resumo:
BACKGROUND: Palliative medicine has made rapid progress in establishing its scientific and clinical legitimacy, yet the evidence base to support clinical practice remains deficient in both the quantity and quality of published studies. Historically, the conduct of research in palliative care populations has been impeded by multiple barriers including health care system fragmentation, small number and size of potential sites for recruitment, vulnerability of the population, perceptions of inappropriateness, ethical concerns, and gate-keeping. METHODS: A group of experienced investigators with backgrounds in palliative care research convened to consider developing a research cooperative group as a mechanism for generating high-quality evidence on prioritized, clinically relevant topics in palliative care. RESULTS: The resulting Palliative Care Research Cooperative (PCRC) agreed on a set of core principles: active, interdisciplinary membership; commitment to shared research purposes; heterogeneity of participating sites; development of research capacity in participating sites; standardization of methodologies, such as consenting and data collection/management; agile response to research requests from government, industry, and investigators; focus on translation; education and training of future palliative care researchers; actionable results that can inform clinical practice and policy. Consensus was achieved on a first collaborative study, a randomized clinical trial of statin discontinuation versus continuation in patients with a prognosis of less than 6 months who are taking statins for primary or secondary prevention. This article describes the formation of the PCRC, highlighting processes and decisions taken to optimize the cooperative group's success.
Resumo:
Secure Access For Everyone (SAFE), is an integrated system for managing trust
using a logic-based declarative language. Logical trust systems authorize each
request by constructing a proof from a context---a set of authenticated logic
statements representing credentials and policies issued by various principals
in a networked system. A key barrier to practical use of logical trust systems
is the problem of managing proof contexts: identifying, validating, and
assembling the credentials and policies that are relevant to each trust
decision.
SAFE addresses this challenge by (i) proposing a distributed authenticated data
repository for storing the credentials and policies; (ii) introducing a
programmable credential discovery and assembly layer that generates the
appropriate tailored context for a given request. The authenticated data
repository is built upon a scalable key-value store with its contents named by
secure identifiers and certified by the issuing principal. The SAFE language
provides scripting primitives to generate and organize logic sets representing
credentials and policies, materialize the logic sets as certificates, and link
them to reflect delegation patterns in the application. The authorizer fetches
the logic sets on demand, then validates and caches them locally for further
use. Upon each request, the authorizer constructs the tailored proof context
and provides it to the SAFE inference for certified validation.
Delegation-driven credential linking with certified data distribution provides
flexible and dynamic policy control enabling security and trust infrastructure
to be agile, while addressing the perennial problems related to today's
certificate infrastructure: automated credential discovery, scalable
revocation, and issuing credentials without relying on centralized authority.
We envision SAFE as a new foundation for building secure network systems. We
used SAFE to build secure services based on case studies drawn from practice:
(i) a secure name service resolver similar to DNS that resolves a name across
multi-domain federated systems; (ii) a secure proxy shim to delegate access
control decisions in a key-value store; (iii) an authorization module for a
networked infrastructure-as-a-service system with a federated trust structure
(NSF GENI initiative); and (iv) a secure cooperative data analytics service
that adheres to individual secrecy constraints while disclosing the data. We
present empirical evaluation based on these case studies and demonstrate that
SAFE supports a wide range of applications with low overhead.