A perspective on specifying and verifying concurrent modules

The specification of a concurrent program module, and the verification of implementations and clients with respect to such a specification, are difficult problems. A specification should be general enough that any reasonable implementation satisfies it, yet precise enough that it can be used by any reasonable client. We survey a range of techniques for specifying concurrent modules, using the example of a counter module to illustrate the benefits and limitations of each. In particular, we highlight four key concepts underpinning these techniques: auxiliary state, interference abstraction, resource ownership and atomicity. We demonstrate how these concepts can be combined to achieve two powerful approaches for specifying concurrent modules and verifying implementations and clients, which remove the limitations highlighted by the counter example

Differential analysis of biological networks

In cancer research, the comparison of gene expression or DNA methylation networks inferred from healthy controls and patients can lead to the discovery of biological pathways associated to the disease. As a cancer progresses, its signalling and control networks are subject to some degree of localised re-wiring. Being able to detect disrupted interaction patterns induced by the presence or progression of the disease can lead to the discovery of novel molecular diagnostic and prognostic signatures. Currently there is a lack of scalable statistical procedures for two-network comparisons aimed at detecting localised topological differences. We propose the dGHD algorithm, a methodology for detecting differential interaction patterns in two-network comparisons. The algorithm relies on a statistic, the Generalised Hamming Distance (GHD), for assessing the degree of topological difference between networks and evaluating its statistical significance. dGHD builds on a non-parametric permutation testing framework but achieves computationally efficiency through an asymptotic normal approximation. We show that the GHD is able to detect more subtle topological differences compared to a standard Hamming distance between networks. This results in the dGHD algorithm achieving high performance in simulation studies as measured by sensitivity and specificity. An application to the problem of detecting differential DNA co-methylation subnetworks associated to ovarian cancer demonstrates the potential benefits of the proposed methodology for discovering network-derived biomarkers associated with a trait of interest

Asian Americans respond less favorably to excitement (vs. calm)-focused physicians compared to European Americans

OBJECTIVES: Despite being considered a model minority, Asian Americans report worse health care encounters than do European Americans. This may be due to affective mismatches between Asian American patients and their European American physicians. We predicted that because Asian Americans value excitement (vs. calm) less than European Americans, they will respond less favorably to excitement-focused (vs. calm) physicians. METHOD: In Study 1, 198 European American, Chinese American, and Hong Kong Chinese community adults read a medical scenario and indicated their preference for an excitement-focused versus calm-focused physician. In Study 2, 81 European American and Asian American community college students listened to recommendations made by an excitement-focused or calm-focused physician in a video, and later attempted to recall the recommendations. In Study 3, 101 European American and Asian American middle-aged and older adults had multiple online encounters with an excitement-focused or calm-focused physician and then evaluated their physicians\u27 trustworthiness, competence, and knowledge. RESULTS: As predicted, Hong Kong Chinese preferred excitement-focused physicians less than European Americans, with Chinese Americans falling in the middle (Study 1). Similarly, Asian Americans remembered health information delivered by an excitement-focused physician less well than did European Americans (Study 2). Finally, Asian Americans evaluated an excitement-focused physician less positively than did European Americans (Study 3). CONCLUSIONS: These findings suggest that while physicians who promote and emphasize excitement states may be effective with European Americans, they may be less so with Asian Americans and other ethnic minorities who value different affective states

Inversion of exciton level splitting in quantum dots

The demonstration of degeneracy of exciton spin states is an important step toward the production of entangled photon pairs from the biexciton cascade. We measure the fine structure of exciton and biexciton states for a large number of single InAs quantum dots in a GaAs matrix; the energetic splitting of the horizontally and vertically polarized components of the exciton doublet is shown to decrease as the exciton confinement decreases, crucially passing through zero and changing sign. Thermal annealing is shown to reduce the exciton confinement, thereby increasing the number of dots with splitting close to zero

Modular termination verification for non-blocking concurrency

© Springer-Verlag Berlin Heidelberg 2016.We present Total-TaDA, a program logic for verifying the total correctness of concurrent programs: that such programs both terminate and produce the correct result. With Total-TaDA, we can specify constraints on a thread’s concurrent environment that are necessary to guarantee termination. This allows us to verify total correctness for nonblocking algorithms, e.g. a counter and a stack. Our specifications can express lock- and wait-freedom. More generally, they can express that one operation cannot impede the progress of another, a new non-blocking property we call non-impedance. Moreover, our approach is modular. We can verify the operations of a module independently, and build up modules on top of each other

Quantum electric-dipole liquid on a triangular lattice

Geometric frustrations and quantum mechanical fluctuations may prohibit the formation of long-range ordering even at the lowest temperature, and therefore liquid-like ground states could be expected. A good example is the quantum spin liquid in frustrated magnets that represents an exotic phase of matter and is attracting enormous interests. Geometric frustrations and quantum fluctuations can happen beyond magnetic systems. Here we propose that quantum electric-dipole liquids, analogs to quantum spin liquids, could emerge in frustrated dielectrics where antiferroelectrically coupled small electric dipoles reside on a triangular lattice. The quantum paraelectric hexaferrite BaFe12O19, in which small electric dipoles originated from the off-center displacement of Fe3+ in the FeO5 bipyramids constitute a two-dimensional triangular lattice, represents a promising candidate to generate the anticipated electric-dipole liquid. We present a series of experimental evidences, including dielectric permittivity, heat capacity, and thermal conductivity measured down to 66 mK, to reveal the existence of a nontrivial ground state in BaFe12O19, characterized by itinerant low-energy excitations with a small gap, to which we interpret as an exotic liquid-like quantum phase. The quantum electric-dipole liquids in frustrated dielectrics open up a fresh playground for fundamental physics and may find applications in quantum information and computation as well.Comment: 13 pages, 6 figure

Controlling the polarisation correlation of photon pairs from a charge-tuneable quantum dot

Correlation between the rectilinear polarisations of the photons emitted from the biexciton decay in a single quantum dot is investigated in a device which allows the charge-state of the dot to be controlled. Optimising emission from the neutral exciton states maximises the operating efficiency of the biexciton decay. This is important for single dot applications such as a triggered source of entangled photons. As the bias on the device is reduced correlation between the two photons is found to fall dramatically as emission from the negatively charged exciton becomes significant. Lifetime measurements demonstrate that electronic spin-scattering is the likely cause.Comment: 3 figure

Judges and judging in the Court of Final Appeal: a statistical picture

The authors provide a unique perspective on how the Court of Final Appeal has operated from 1997 to 2010. The study tracks the rising caseload in the Court, considers the statistical profile of the new system of judges and notes the greater attention being paid by the final court to public law cases.published_or_final_versio

Specifying and Verifying Concurrent Algorithms with Histories and Subjectivity

We present a lightweight approach to Hoare-style specifications for fine-grained concurrency, based on a notion of time-stamped histories that abstractly capture atomic changes in the program state. Our key observation is that histories form a partial commutative monoid, a structure fundamental for representation of concurrent resources. This insight provides us with a unifying mechanism that allows us to treat histories just like heaps in separation logic. For example, both are subject to the same assertion logic and inference rules (e.g., the frame rule). Moreover, the notion of ownership transfer, which usually applies to heaps, has an equivalent in histories. It can be used to formally represent helping---an important design pattern for concurrent algorithms whereby one thread can execute code on behalf of another. Specifications in terms of histories naturally abstract granularity, in the sense that sophisticated fine-grained algorithms can be given the same specifications as their simplified coarse-grained counterparts, making them equally convenient for client-side reasoning. We illustrate our approach on a number of examples and validate all of them in Coq.Comment: 17 page

??????????????? ????????? ????????? ?????? ??? ????????????

??????????????? ????????? ???????????? ???????????? ?????? ?????????????????? ??????????????? ?????? ???????????? ??????. ??? ??????????????? ??????????????? ??? ?????? ????????? ???????????? ????????? ??????????????? ????????? ???????????????. ?????? ??????????????? ????????? ??? ?????? ????????? ???????????????, ??? ?????? ????????? diethylnitrosamine (DEN)??? C3H/HeN ?????? ?????? ?????? ???????????? ??? ?????? ????????? ????????? ???????????????. DEN?????? ????????? ???????????? ?????? alkaline phosphatase (ALP) ??????, TUNEL positive ???????????? ??????, ??? ???????????? ?????? ???????????? duct??? ??????, ?????????????????? ????????????, Masson???s trichrome ???????????? ????????? ???????????? ???, ?????? ?????? ?????? ??? ????????? ????????? ???????????? ?????? ???????????? ?????? ?????? ????????? ??? ?????????. ?????????, ??????????????? ?????? ???????????? ????????? ?????? ?????????????????? ??????, ?????? ?????? ??? ????????? ???????????? ??????????????? ???????????? ???????????? ???????????? ?????? ?????? ????????? ??? ?????????. ???????????? ???????????? ????????? ???????????? ??????, ???????????? ???????????? ???????????? ?????? ????????? ???, solvent partition ????????? ???????????? ????????? ???????????? hexane, ethyl acetate, water ???????????? ???????????????. ?????? ??????????????? ?????? ????????? ??????????????? ??????????????? ???, ethyl acetate ???????????? ??????????????? ????????? ?????????????????? ??????????????? ?????? ??????????????? ???????????? ????????? ????????? ????????? ??? ?????????. ????????? ethyl acetate???????????? ???????????? ????????? ????????? ??? ?????????, ??????????????? ????????? ??? ?????? ????????? ????????? ?????????. ???????????????, ??????????????? ????????? ????????????????????? ?????? ????????? ??? ?????? ????????? ???????????? ?????? ??????????????? ????????? ??? ?????? ????????? ????????? ????????? ?????? ???????????????. ?????????, ?????? ??????????????? ?????? ???????????? ?????? ??? ?????? ?????? ???????????? ??????????????? ?????? ????????? ????????? ??? ?????? ????????? ???????????? ??????.clos