1,829 research outputs found
Term Risk in Interest Rate Markets
Using a stylised financial system along with a systemic perspective thereof, the definition of an aggregated banking system that is default-free but vulnerable to liquidity risks is enabled. Within this setup, a consistent mathematical modelling framework for term interest rate systems is derived that enables the pricing and valuation of associated linear derivative instruments. It is then demonstrated that term rates may not be synthetically replicated, in general, which in turn enables the extraction and explanation of the genesis of term risk. These findings provide: (i) a rigorous understanding of the incomplete market paradigm that encapsulates inter-bank term rates and the risk management processes involved therein; and (ii) quantitative theoretical evidence against global interest rate reform proposals advocating for the replacement of term Libor (London inter-bank offered rate) reference rates with overnight rate-based alternatives
Cryptococcal choroiditis in advanced AIDS with clinicopathologic correlation.
PurposeTo describe a case of disseminated cryptococcal meningitis with multifocal choroiditis and provide optical coherence tomography (OCT) findings correlated with described histopathology in a patient with advanced acquired immunodeficiency syndrome (AIDS).ObservationsThe patient was a 54-year-old man with AIDS who presented with dyspnea and headache followed by acute vision loss. OCT demonstrated a lesion with a small area of fluid that was limited by a more prominent and irregular external limiting membrane with underlying nodular choroidal thickening, mild RPE disorganization, and hyperreflectivity of the overlying photoreceptor layer. Patient was found to have disseminated cryptococcal infection and passed away despite aggressive therapy. Autopsy was performed including bilateral enucleation and a Cryptococcus lesion was confirmed on histopathology.Conclusion and importanceThis case highlights the clinical, imaging, and histopathologic findings of cryptococcal choroiditis and provides a review of the updated treatment recommendations for disseminated infection in a patient with advanced AIDS. Although currently fundoscopy has proven most useful in directing the diagnostic algorithm in choroiditis in the setting of advanced immunosuppression, OCT may provide insight into the spread of Cryptococcus within the eye
Sphingosine kinase 1 is up-regulated during hypoxia in U87MG glioma cells: Role of hypoxia-inducible factors 1 and 2
Sphingosine 1-phosphate (S1P), a sphingolipid metabolite that plays an important role in the regulation of cell survival, growth, migration, and angiogenesis, acts both inside the cells and as an extracellular mediator through binding to five G protein-coupled receptors (S1P(1-5)). Sphingosine kinase 1 (SK1), the enzyme responsible for S1P production, is overexpressed in many solid tumors, including gliomas. One common feature of these tumors is the presence of "hypoxic regions," characterized by cells expressing high levels of hypoxia-inducible factors HIF-1alpha and HIF-2alpha, two transcription regulators that modulate the levels of proteins with crucial roles in tumor progression. So far, nothing is known about the role and the regulation of SK1 during tumor-induced hypoxia or about SK1 regulation and HIFs. Here we investigated the role of HIF-1alpha and HIF-2alpha in the regulation of SK1 during hypoxic stress in glioma-derived U87MG cells. We report that hypoxia increases SK1 mRNA levels, protein expression, and enzyme activity, followed by intracellular S1P production and S1P release. Interestingly, knockdown of HIF-2alpha by small interfering RNA abolished the induction of SK1 and the production of extracellular S1P after CoCl(2) treatment, whereas HIF-1alpha small interfering RNA resulted in an increase of HIF-2alpha and of SK1 protein levels. Moreover, using chromatin immunoprecipitation analysis, we demonstrate that HIF-2alpha binds the SK1 promoter. Functionally, we demonstrate that conditioned medium from hypoxia-treated tumor cells results in neoangiogenesis in human umbilical vein endothelial cells in a S1P receptor-dependent manner. These studies provide evidence of a link between S1P production as a potent angiogenic agent and the hypoxic phenotype observed in many tumors
COVID-19 and lung cancer: risks, mechanisms and treatment interactions.
Cases of the 2019 novel coronavirus also known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continue to rise worldwide. To date, there is no effective treatment. Clinical management is largely symptomatic, with organ support in intensive care for critically ill patients. The first phase I trial to test the efficacy of a vaccine has recently begun, but in the meantime there is an urgent need to decrease the morbidity and mortality of severe cases. It is known that patients with cancer are more susceptible to infection than individuals without cancer because of their systemic immunosuppressive state caused by the malignancy and anticancer treatments. Therefore, these patients might be at increased risk of pulmonary complications from COVID-19. The SARS-CoV-2 could in some case induce excessive and aberrant non-effective host immune responses that are associated with potentially fatal severe lung injury and patients can develop acute respiratory distress syndrome (ARDS). Cytokine release syndrome and viral ARDS result from uncontrolled severe acute inflammation. Acute lung injury results from inflammatory monocyte and macrophage activation in the pulmonary luminal epithelium which lead to a release of proinflammatory cytokines including interleukin (IL)-6, IL-1 and tumor necrosis factor-α. These cytokines play a crucial role in immune-related pneumonitis, and could represent a promising target when the infiltration is T cell predominant or there are indirect signs of high IL-6-related inflammation, such as elevated C-reactive protein. A monoclonal anti-IL-6 receptor antibody, tocilizumab has been administered in a number of cases in China and Italy. Positive clinical and radiological outcomes have been reported. These early findings have led to an ongoing randomized controlled clinical trial in China and Italy. While data from those trials are eagerly awaited, patients' management will continue to rely for the vast majority on local guidelines. Among many other aspects, this crisis has proven that different specialists must join forces to deliver the best possible care to patients
State selection in the noisy stabilized Kuramoto-Sivashinsky equation
In this work, we study the 1D stabilized Kuramoto Sivashinsky equation with
additive uncorrelated stochastic noise. The Eckhaus stable band of the
deterministic equation collapses to a narrow region near the center of the
band. This is consistent with the behavior of the phase diffusion constants of
these states. Some connections to the phenomenon of state selection in driven
out of equilibrium systems are made.Comment: 8 pages, In version 3 we corrected minor/typo error
HW/SW Architecture Exploration for an Efficient Implementation of the Secure Hash Algorithm SHA-256
Hash functions are used in the majority of security protocol to guarantee the integrity and the authenticity. Among the most important hash functions is the SHA-2 family, which offers higher security and solved the insecurity problems of other popular algorithms as MD5, SHA-1 and SHA-0. However, theses security algorithms are characterized by a certain amount of complex computations and consume a lot of energy. In order to reduce the power consumption as required in the majority of embedded applications, a solution consists to exploit a critical part on accelerator (hardware). In this paper, we propose a hardware/software exploration for the implementation of SHA256 algorithm. For hardware design, two principal design methods are proceeded: Low level synthesis (LLS) and high level synthesis (HLS). The exploration allows the evaluation of performances in term of area, throughput and power consumption. The synthesis results under Zynq 7000 based-FPGA reflect a significant improvement of about 80% and 15% respectively in FPGA resources and throughput for the LLS hardware design compared to HLS solution. For better efficiency, hardware IPs are deduced and implemented within HW/SW system on chip. The experiments are performed using Xilinx ZC 702-based platform. The HW/SW LLS design records a gain of 10% to 25% in term of execution time and 73% in term of power consumption
E2 strengths and transition radii difference of one-phonon 2+ states of 92Zr from electron scattering at low momentum transfer
Background: Mixed-symmetry 2+ states in vibrational nuclei are characterized
by a sign change between dominant proton and neutron valence-shell components
with respect to the fully symmetric 2+ state. The sign can be measured by a
decomposition of proton and neutron transition radii with a combination of
inelastic electron and hadron scattering [C. Walz et al., Phys. Rev. Lett. 106,
062501 (2011)]. For the case of 92Zr, a difference could be experimentally
established for the neutron components, while about equal proton transition
radii were indicated by the data. Method: Differential cross sections for the
excitation of one-phonon 2+ and 3- states in 92Zr have been measured with the
(e,e') reaction at the S-DALINAC in a momentum transfer range q = 0.3-0.6
fm^(-1). Results: Transition strengths B(E2;2+_1 -> 0+_1) = 6.18(23), B(E2;
2+_2 -> 0+_1) = 3.31(10) and B(E3; 3-_1 -> 0+_1) = 18.4(11) Weisskopf units are
determined from a comparison of the experimental cross sections to
quasiparticle-phonon model (QPM) calculations. It is shown that a
model-independent plane wave Born approximation (PWBA) analysis can fix the
ratio of B(E2) transition strengths to the 2+_(1,2) states with a precision of
about 1%. The method furthermore allows to extract their proton transition
radii difference. With the present data -0.12(51) fm is obtained. Conclusions:
Electron scattering at low momentum transfers can provide information on
transition radii differences of one-phonon 2+ states even in heavy nuclei.
Proton transition radii for the 2+_(1,2) states in 92Zr are found to be
identical within uncertainties. The g.s. transition probability for the
mixed-symmetry state can be determined with high precision limited only by the
available experimental information on the B(E2; 2+_1 -> 0+_1) value.Comment: 14 pages, 5 figures, submitted to Phys. Rev. C, revised manuscrip
Towards Optimised FPGA Realisation of Microprogrammed Control Unit Based FIR Filters
Finite impulse response (FIR) filter is one of the most common type of digital filter used in digital signal processing (DSP) applications. An FIR filter is usually realised in hardware using multipliers, adders and registers. Field programmable gate arrays (FPGAs) have been widely explored for the hardware realisation of FIR filters using different algorithms and techniques. One such technique that has recently gained considerable attention is the use of microprogrammed control unit (MPCU) in designing FIR filters. In this chapter, we further explore MPCU technique for optimised hardware realisation of digital FIR filter. To evaluate the performance, two different architectures of FIR filter are designed using Wallace tree multiplier. Both the architectures are coded in Verilog hardware description language (HDL). The performance is analysed by evaluating the resource utilisation and timing reports of Virtex-5 FPGA generated by the Synopsys Synplify Pro tool. Based on the implementation results, as compared to conventional design, Wallace tree multiplier using carry skip adder (CSKA) provides optimal digital FIR filter
A pilot Citizens' Assembly on Electricity and Energy Justice in Hamra, Lebanon
The Citizens’ Assembly Pilot (CA) on energy justice and electricity was a conceptual and a methodological experiment conducted over five sessions over three days in the neighborhood of Hamra and Beirut in October and November 2020. The CA aimed at exploring meanings, dimensions, priorities of energy justice in a deliberative democratic setting. The CA tackled five main questions: How did we get to where we are? What is energy justice to us? What is the energy-mix we would like to have? What do we need to be doing as individuals and communities to achieve a better energy future? How should we move forward with our decisions on the above questions? The responses produced interesting findings for researchers and international stakeholders to consider further; such as skepticism over renewable energy targets, the interest in circular solutions to solve multiple intersecting service sectors like waste and water in particular. It also raised questions over decentralization as well as privatization at different scales of governance
- …