348 research outputs found
Geometric entropy, area, and strong subadditivity
The trace over the degrees of freedom located in a subset of the space
transforms the vacuum state into a density matrix with non zero entropy. This
geometric entropy is believed to be deeply related to the entropy of black
holes. Indeed, previous calculations in the context of quantum field theory,
where the result is actually ultraviolet divergent, have shown that the
geometric entropy is proportional to the area for a very special type of
subsets. In this work we show that the area law follows in general from simple
considerations based on quantum mechanics and relativity. An essential
ingredient of our approach is the strong subadditive property of the quantum
mechanical entropy.Comment: Published versio
Partnership, ownership and control: the impact of corporate governance on employment relations
Prevailing patterns of dispersed share ownership and rules of corporate governance for UK listed companies appear to constrain the ability of managers to make credible, long-term commitments to employees of the kind needed to foster effective labour-management partnerships. We present case study evidence which suggests that such partnerships can nevertheless emerge where product market conditions and the regulatory environment favour a stakeholder orientation. Proactive and mature partnerships may also be sustained where the board takes a strategic approach to mediating between the claims of different stakeholder groups, institutional investors are prepared to take a long-term view of their holdings, and strong and independent trade unions are in a position to facilitate organisational change
The Quest for Uniformity in Mediation Confidentiality: Foolish Consistency or Crucial Predictability?
Integrated Pharmacodynamic Analysis Identifies Two Metabolic Adaption Pathways to Metformin in Breast Cancer.
Late-phase clinical trials investigating metformin as a cancer therapy are underway. However, there remains controversy as to the mode of action of metformin in tumors at clinical doses. We conducted a clinical study integrating measurement of markers of systemic metabolism, dynamic FDG-PET-CT, transcriptomics, and metabolomics at paired time points to profile the bioactivity of metformin in primary breast cancer. We show metformin reduces the levels of mitochondrial metabolites, activates multiple mitochondrial metabolic pathways, and increases 18-FDG flux in tumors. Two tumor groups are identified with distinct metabolic responses, an OXPHOS transcriptional response (OTR) group for which there is an increase in OXPHOS gene transcription and an FDG response group with increased 18-FDG uptake. Increase in proliferation, as measured by a validated proliferation signature, suggested that patients in the OTR group were resistant to metformin treatment. We conclude that mitochondrial response to metformin in primary breast cancer may define anti-tumor effect
Interspecific Hybridization and Mitochondrial Introgression in Invasive Carcinus Shore Crabs
Interspecific hybridization plays an important role in facilitating adaptive
evolutionary change. More specifically, recent studies have demonstrated that
hybridization may dramatically influence the establishment, spread, and impact
of invasive populations. In Japan, previous genetic evidence for the presence of
two non-native congeners, the European green crab Carcinus
maenas and the Mediterranean green crab C.
aestuarii, has raised questions regarding the possibility of
hybridization between these sister species. Here I present analysis based on
both nuclear microsatellites and the mitochondrial cytochrome C oxidase subunit
I (COI) gene which unambiguously argues for a hybrid origin of Japanese
Carcinus. Despite the presence of mitochondrial lineages
derived from both C. maenas and C. aestuarii,
the Japanese population is panmictic at nuclear loci and has achieved
cytonuclear equilibrium throughout the sampled range in Japan. Furthermore,
analysis of admixture at nuclear loci indicates dramatic introgression of the
C. maenas mitochondrial genome into a predominantly
C. aestuarii nuclear background. These patterns, along with
inferences drawn from the observational record, argue for a hybridization event
pre-dating the arrival of Carcinus in Japan. The clarification
of both invasion history and evolutionary history afforded by genetic analysis
provides information that may be critically important to future studies aimed at
assessing risks posed by invasive Carcinus populations to Japan
and the surrounding region
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