Dispersion interactions between semiconducting wires

The dispersion energy between extended molecular chains (or equivalently infinite wires) with non-zero band gaps is generally assumed to be expressible as a pair-wise sum of atom-atom terms which decay as $R^{-6}$. Using a model system of two parallel wires with a variable band gap, we show that this is not the case. The dispersion interaction scales as $z^{-5}$ for large interwire separations $z$, as expected for an insulator, but as the band gap decreases the interaction is greatly enhanced; while at shorter (but non-overlapping) separations it approaches a power-law scaling given by $z^{-2}$, \emph{i.e.} the dispersion interaction expected between \emph{metallic} wires. We demonstrate that these effects can be understood from the increasing length scale of the plasmon modes (charge fluctuations), and their increasing contribution to the molecular dipole polarizability and the dispersion interaction, as the band gaps are reduced. This result calls into question methods which invoke locality assumptions in deriving dispersion interactions between extended small-gap systems.Comment: 8 pages, 5 figure

Arms Industry

A summary assessment of the dimensions and concentrations of military equipment manufacture primarily in the United States and western Europe and the extent of availability of this equipment to buyers throughout the world. Treaty-based limitations are also listed

Complete resummation of chirally-enhanced loop-effects in the MSSM with non-minimal sources of flavor-violation

In this article we present the complete resummation of the leading chirally-enhanced corrections stemming from gluino-squark, chargino-sfermion and neutralino-sfermion loops in the MSSM with non-minimal sources of flavor-violation. We compute the finite renormalization of fermion masses and the CKM matrix induced by chirality-flipping self-energies. In the decoupling limit Msusy>>v, which is an excellent approximation to the full theory, we give analytic results for the effective gaugino(higgsino)-fermion-sfermion and the Higgs-fermion-fermion vertices. Using these vertices as effective Feynman rules, all leading chirally-enhanced corrections can consistently be included into perturbative calculations of Feynman amplitudes. We also give a generalized parametrization for the bare CKM matrix which extends the classic Wolfenstein parametrization to the case of complex parameters lambda and A.Comment: 31 pages, 3 figures; typos correcte

Privacy-Preserving Trust Management Mechanisms from Private Matching Schemes

Cryptographic primitives are essential for constructing privacy-preserving communication mechanisms. There are situations in which two parties that do not know each other need to exchange sensitive information on the Internet. Trust management mechanisms make use of digital credentials and certificates in order to establish trust among these strangers. We address the problem of choosing which credentials are exchanged. During this process, each party should learn no information about the preferences of the other party other than strictly required for trust establishment. We present a method to reach an agreement on the credentials to be exchanged that preserves the privacy of the parties. Our method is based on secure two-party computation protocols for set intersection. Namely, it is constructed from private matching schemes.Comment: The material in this paper will be presented in part at the 8th DPM International Workshop on Data Privacy Management (DPM 2013

A review of human factors principles for the design and implementation of medication safety alerts in clinical information systems.

The objective of this review is to describe the implementation of human factors principles for the design of alerts in clinical information systems. First, we conduct a review of alarm systems to identify human factors principles that are employed in the design and implementation of alerts. Second, we review the medical informatics literature to provide examples of the implementation of human factors principles in current clinical information systems using alerts to provide medication decision support. Last, we suggest actionable recommendations for delivering effective clinical decision support using alerts. A review of studies from the medical informatics literature suggests that many basic human factors principles are not followed, possibly contributing to the lack of acceptance of alerts in clinical information systems. We evaluate the limitations of current alerting philosophies and provide recommendations for improving acceptance of alerts by incorporating human factors principles in their design

Prevalence of abnormal findings in 230 knees of asymptomatic adults using 3.0 T MRI.

OBJECTIVE: To identify abnormalities in asymptomatic sedentary individuals using 3.0 Tesla high-resolution MRI. MATERIALS AND METHODS: The cohort comprised of 230 knees of 115 uninjured sedentary adults (51 males, 64 females; median age: 44 years). All participants had bilateral knee 3.0 T MRIs. Two senior musculoskeletal radiologists graded all intraarticular knee structures using validated scoring systems. Participants completed Knee Injury and Osteoarthritis Outcome Score questionnaires at the time of the MRI scan. RESULTS: MRI showed abnormalities in the majority (97%) of knees. Thirty percent knees had meniscal tears: horizontal (23%), complex (3%), vertical (2%), radial (2%) and bucket handle (1%). Cartilage and bone marrow abnormalities were prevalent at the patellofemoral joint (57% knees and 48% knees, respectively). Moderate and severe cartilage lesions were common, in 19% and 31% knees, respectively, while moderate and severe bone marrow oedema in 19% and 31% knees, respectively. Moderate-intensity lesion in tendons was found in 21% knees and high-grade tendonitis in 6% knees-the patellar (11% and 2%, respectively) and quadriceps (7% and 2%, respectively) tendons being most affected. Three percent partial ligamentous ruptures were found, especially of the anterior cruciate ligament (2%). CONCLUSION: Nearly all knees of asymptomatic adults showed abnormalities in at least one knee structure on MRI. Meniscal tears, cartilage and bone marrow lesions of the patellofemoral joint were the most common pathological findings. Bucket handle and complex meniscal tears were reported for the first time in asymptomatic knees

Is the immediate effect of marathon running on novice runners' knee joints sustained within 6 months after the run? A follow-up 3.0 T MRI study.

OBJECTIVE: To evaluate changes in the knee joints of asymptomatic first-time marathon runners, using 3.0 T MRI, 6 months after finishing marathon training and run. MATERIALS AND METHODS: Six months after their participation in a baseline study regarding their knee joints, 44 asymptomatic novice marathoners (17 males, 27 females, mean age 46 years old) agreed to participate in a repeat MRI investigation: 37 completed both a standardized 4-month-long training programme and the marathon (marathon runners); and 7 dropped out during training (pre-race dropouts). The participants already underwent bilateral 3.0 T MRIs: 6 months before and 2 weeks after their first marathon, the London Marathon 2017. This study was a follow-up assessment of their knee joints. Each knee structure was assessed using validated scoring/grading systems at all time points. RESULTS: Two weeks after the marathon, 3 pre-marathon bone marrow lesions and 2 cartilage lesions showed decrease in radiological score on MRI, and the improvement was sustained at the 6-month follow-up. New improvements were observed on MRI at follow-up: 5 pre-existing bone marrow lesions and 3 cartilage lesions that remained unchanged immediately after the marathon reduced in their extent 6 months later. No further lesions appeared at follow-up, and the 2-week post-marathon lesions showed signs of reversibility: 10 of 18 bone marrow oedema-like signals and 3 of 21 cartilage lesions decreased on MRI. CONCLUSION: The knees of novice runners achieved sustained improvement, for at least 6 months post-marathon, in the condition of their bone marrow and articular cartilage

Speciesistic Veganism: An Anthropocentric Argument

The paper proposes an anthropocentric argument for veganism based on a speciesistic premise that most carnists likely affirm: human flourishing should be promoted. I highlight four areas of human suffering promoted by a carnistic diet: (1) health dangers to workers (both physical and psychological), (2) economic dangers to workers, (3) physical dangers to communities around slaughterhouses, and (4) environmental dangers to communities-at-large. Consequently, one could ignore the well-being of non-human animals and nevertheless recognize significant moral failings in the current standard system of meat production