476 research outputs found
Phase Transitions and Conductivties of Floquet Fluids
We investigate the phase structure and conductivity of a relativistic fluid
in a circulating electric field with a transverse magnetic field. This system
exhibits behavior similar to other driven systems such as strongly coupled
driven CFTs [Rangamani2015] or a simple anharmonic oscillator. We identify
distinct regions of fluid behavior as a function of driving frequency, and
argue that a "phase" transition will occur. Such a transition could be
measurable in graphene, and may be characterized by sudden discontinuous
increase in the Hall conductivity. The presence of the discontinuity depends on
how the boundary is approached as the frequency or amplitude is dialed. In the
region where two solution exists the measured conductivity will depend on how
the system is prepared.Comment: v2: corrected typos and updated reference
Retroperitoneal Sarcoma With Infected Necrosis: An Unfavourable Prognostic Factor
Purpose. To report the phenomenon of infected retroperitoneal sarcoma (RPS)
Culture and Development: Practical illustrations from the Commonwealth
The examples set out in this paper highlight some of the practical ways in which culture and development are being linked in practice. They have been drawn from submissions made by civil society organisations to the Commonwealth Group on Culture and Development1 and offer practical examples to support the Group’s Commonwealth Statement on Culture and Development. They aim to shed light on the Group’s recommendations and show potential ways in which they can be taken forward in practice. The four examples illustrate how culture-based methods and resources can support social transformation, realise economic benefits
and foster community cohesion
Reconfigurable quantum metamaterials
By coupling controllable quantum systems into larger structures we introduce
the concept of a quantum metamaterial. Conventional meta-materials represent
one of the most important frontiers in optical design, with applications in
diverse fields ranging from medicine to aerospace. Up until now however,
metamaterials have themselves been classical structures and interact only with
the classical properties of light. Here we describe a class of dynamic
metamaterials, based on the quantum properties of coupled atom-cavity arrays,
which are intrinsically lossless, reconfigurable, and operate fundamentally at
the quantum level. We show how this new class of metamaterial could be used to
create a reconfigurable quantum superlens possessing a negative index gradient
for single photon imaging. With the inherent features of quantum superposition
and entanglement of metamaterial properties, this new class of dynamic quantum
metamaterial, opens a new vista for quantum science and technology.Comment: 16 pages, 8 figure
Detection of weak ELNES signals using dose-fractionated spectrum imaging combined with direct detection
1 Versus 2-cm Excision Margins for pT2-pT4 Primary Cutaneous Melanoma (MelMarT): A Feasibility Study
Abstract
Background
There is a lack of consensus regarding optimal surgical excision margins for primary cutaneous melanoma > 1 mm in Breslow thickness (BT). A narrower surgical margin is expected to be associated with lower morbidity, improved quality of life (QoL), and reduced cost. We report the results of a pilot international study (MelMarT) comparing a 1 versus 2-cm surgical margin for patients with primary melanoma > 1 mm in BT.
Methods
This phase III, multicentre trial [NCT02385214] administered by the Australia & New Zealand Medical Trials Group (ANZMTG 03.12) randomised patients with a primary cutaneous melanoma > 1 mm in BT to a 1 versus 2-cm wide excision margin to be performed with sentinel lymph node biopsy. Surgical closure technique was at the discretion of the treating surgeon. Patients’ QoL was measured (FACT-M questionnaire) at baseline, 3, 6, and 12 months after randomisation.
Results
Between January 2015 and June 2016, 400 patients were randomised from 17 centres in 5 countries. A total of 377 patients were available for analysis. Primary melanomas were located on the trunk (56.9%), extremities (35.6%), and head and neck (7.4%). More patients in the 2-cm margin group required reconstruction (34.9 vs. 13.6%; p < 0.0001). There was an increased wound necrosis rate in the 2-cm arm (0.5 vs. 3.6%; p = 0.036). After 12 months’ follow-up, no differences were noted in QoL between groups.
Discussion
This pilot study demonstrates the feasibility of a large international RCT to provide a definitive answer to the optimal excision margin for patients with intermediate- to high-risk primary cutaneous melanoma.
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Genome sequencing of the extinct Eurasian wild aurochs, Bos primigenius, illuminates the phylogeography and evolution of cattle
Background
Domestication of the now-extinct wild aurochs, Bos primigenius, gave rise to the two major domestic extant cattle taxa, B. taurus and B. indicus. While previous genetic studies have shed some light on the evolutionary relationships between European aurochs and modern cattle, important questions remain unanswered, including the phylogenetic status of aurochs, whether gene flow from aurochs into early domestic populations occurred, and which genomic regions were subject to selection processes during and after domestication. Here, we address these questions using whole-genome sequencing data generated from an approximately 6,750-year-old British aurochs bone and genome sequence data from 81 additional cattle plus genome-wide single nucleotide polymorphism data from a diverse panel of 1,225 modern animals.
Results
Phylogenomic analyses place the aurochs as a distinct outgroup to the domestic B. taurus lineage, supporting the predominant Near Eastern origin of European cattle. Conversely, traditional British and Irish breeds share more genetic variants with this aurochs specimen than other European populations, supporting localized gene flow from aurochs into the ancestors of modern British and Irish cattle, perhaps through purposeful restocking by early herders in Britain. Finally, the functions of genes showing evidence for positive selection in B. taurus are enriched for neurobiology, growth, metabolism and immunobiology, suggesting that these biological processes have been important in the domestication of cattle.
Conclusions
This work provides important new information regarding the origins and functional evolution of modern cattle, revealing that the interface between early European domestic populations and wild aurochs was significantly more complex than previously thought
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