3,161 research outputs found
Dispersion insensitive, high-speed optical clock recovery based on a mode-locked laser diode
An investigation into the effects of varying levels of chromatic dispersion on a mode- locked laser diode optical clock recovery process is presented. Results demonstrate that this technique is invariant to input dispersion varying between +75 ps/nm
Formal Analysis of Quantum Systems using Process Calculus
Quantum communication and cryptographic protocols are well on the way to
becoming an important practical technology. Although a large amount of
successful research has been done on proving their correctness, most of this
work does not make use of familiar techniques from formal methods, such as
formal logics for specification, formal modelling languages, separation of
levels of abstraction, and compositional analysis. We argue that these
techniques will be necessary for the analysis of large-scale systems that
combine quantum and classical components, and summarize the results of initial
investigation using behavioural equivalence in process calculus. This paper is
a summary of Simon Gay's invited talk at ICE'11.Comment: In Proceedings ICE 2011, arXiv:1108.014
Real-Time DSP-Free 100Gbit/s/λ PAM-4 Fiber Access Link using EML and Direct Detection
A 100 Gbit/s/ λ PAM-4 fiber link with an optical budget of 30 dB and 20 km fiber reach is achieved in real time experiments. This is compliant with class A (20 dB) point to point (PtP) applications as mobile fronthaul for example, and with class N1 (29 dB) point to multipoint (PtMP) for residential market. We used an integrated externally modulated laser, an analog pre-equalizer, an optical booster amplifier and/or non-filtered preamplifier and direct detection without any digital signal processing (whether real-time or offline)
mTORC2 signaling drives the development and progression of pancreatic cancer
mTOR signaling controls several critical cellular functions and is deregulated in many cancers, including pancreatic cancer. To date, most efforts have focused on inhibiting the mTORC1 complex. However, clinical trials of mTORC1 inhibitors in pancreatic cancer have failed, raising questions about this therapeutic approach. We employed a genetic approach to delete the obligate mTORC2 subunit Rictor and identified the critical times during which tumorigenesis requires mTORC2 signaling. Rictor deletion resulted in profoundly delayed tumorigenesis. Whereas previous studies showed most pancreatic tumors were insensitive to rapamycin, treatment with a dual mTORC1/2 inhibitor strongly suppressed tumorigenesis. In late-stage tumor-bearing mice, combined mTORC1/2 and PI3K inhibition significantly increased survival. Thus, targeting mTOR may be a potential therapeutic strategy in pancreatic cancer
Generalised quantum weakest preconditions
Generalisation of the quantum weakest precondition result of D'Hondt and
Panangaden is presented. In particular the most general notion of quantum
predicate as positive operator valued measure (POVM) is introduced. The
previously known quantum weakest precondition result has been extended to cover
the case of POVM playing the role of a quantum predicate. Additionally, our
result is valid in infinite dimension case and also holds for a quantum
programs defined as a positive but not necessary completely positive
transformations of a quantum states.Comment: 7 pages, no figures, added references, changed conten
PU.1 controls fibroblast polarization and tissue fibrosis
Fibroblasts are polymorphic cells with pleiotropic roles in organ morphogenesis, tissue homeostasis and immune responses. In fibrotic diseases, fibroblasts synthesize abundant amounts of extracellular matrix, which induces scarring and organ failure. By contrast, a hallmark feature of fibroblasts in arthritis is degradation of the extracellular matrix because of the release of metalloproteinases and degrading enzymes, and subsequent tissue destruction. The mechanisms that drive these functionally opposing pro-fibrotic and pro-inflammatory phenotypes of fibroblasts remain unknown. Here we identify the transcription factor PU.1 as an essential regulator of the pro-fibrotic gene expression program. The interplay between transcriptional and post-transcriptional mechanisms that normally control the expression of PU.1 expression is perturbed in various fibrotic diseases, resulting in the upregulation of PU.1, induction of fibrosis-associated gene sets and a phenotypic switch in extracellular matrix-producing pro-fibrotic fibroblasts. By contrast, pharmacological and genetic inactivation of PU.1 disrupts the fibrotic network and enables reprogramming of fibrotic fibroblasts into resting fibroblasts, leading to regression of fibrosis in several organs
The systematic development of a novel integrated spiral undergraduate course in general practice
In 2007 Keele University School of Medicine rolled out its novel curriculum to which general
practice makes a major contribution. In this paper we describe the systematic approach we
took to developing the GP curriculum; from the underlying educational principles which
guided its development, the subsequent decisions we made to the curriculum itself. This
consists of 23 weeks of clinical placements in general practice; four weeks in year 3, four
weeks in year 4 and 15 weeks in year 5. We describe the steps which were necessary to
prepare for the implementation of the GP curriculum.
We consider that the successful implementation of our general practice contribution is a
result of our systematic identification of these principles, the clearly articulated design
decisions and the systematic preparation for implementation involving the academic GP
team and all our potential teaching practices
Performance of the first prototype of the CALICE scintillator strip electromagnetic calorimeter
A first prototype of a scintillator strip-based electromagnetic calorimeter
was built, consisting of 26 layers of tungsten absorber plates interleaved with
planes of 45x10x3 mm3 plastic scintillator strips. Data were collected using a
positron test beam at DESY with momenta between 1 and 6 GeV/c. The prototype's
performance is presented in terms of the linearity and resolution of the energy
measurement. These results represent an important milestone in the development
of highly granular calorimeters using scintillator strip technology. This
technology is being developed for a future linear collider experiment, aiming
at the precise measurement of jet energies using particle flow techniques
Antagonism, accommodation and agonism in critical management studies: alternative organizations as allies
Critical Management Studies has long been engaged in discussions about the purpose of critique and the possibilities of engagement. A recent expression calls for Critical Management Studies to moderate its ânegativeâ critique of management and instead use words like care, engagement and affirmation in order to enable âprogressiveâ engagement with managers. This âperformative turnâ has been poorly received by some who see it as a dilution of radical intent. We argue for a middle ground between the antagonistic versions of Critical Management Studies that appear to want to oppose management, and âperformativeâ scholars who appear to accommodate with managerialism. We do this by planting the debate firmly within an empirical setting and a crisis that the first author experienced as a âcritical scholarâ when conducting an ethnography at a sustainable financial services firm. In order to do this, we explore Chantal Mouffeâs concept of agonism to establish a particular mode of political engagement that acknowledges a space between being âforâ and being âagainstâ. We conclude by suggesting that the exploration of alternative forms of organization and management, themselves already involved in struggle against a hegemonic present, should be the proper task of a discipline that wishes to engage with the present and remain âcritical
The Time Structure of Hadronic Showers in highly granular Calorimeters with Tungsten and Steel Absorbers
The intrinsic time structure of hadronic showers influences the timing
capability and the required integration time of hadronic calorimeters in
particle physics experiments, and depends on the active medium and on the
absorber of the calorimeter. With the CALICE T3B experiment, a setup of 15
small plastic scintillator tiles read out with Silicon Photomultipliers, the
time structure of showers is measured on a statistical basis with high spatial
and temporal resolution in sampling calorimeters with tungsten and steel
absorbers. The results are compared to GEANT4 (version 9.4 patch 03)
simulations with different hadronic physics models. These comparisons
demonstrate the importance of using high precision treatment of low-energy
neutrons for tungsten absorbers, while an overall good agreement between data
and simulations for all considered models is observed for steel.Comment: 24 pages including author list, 9 figures, published in JINS
- âŠ