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Enlightening the dark ages with dark matter
No full textConstraints on dark matter annihilation or decay oer unique insights into the nature of dark matter. We illustrate how surveys dedicated to detect the highly redshifted 21 cm signal from the dark ages will oer a new window into properties of particle dark matter. The 21 cm intensity mapping signal and its uctuations are sensitive to energy injection from annihilation or decay of long-lived particles in a way that is complementary to other probes. We present forecasted constraints from forthcoming and next-generation radio surveys. We show that, while SKA might be capable of a detection for some cases, the most promising opportunity to detect dark matter in the 21 cm intensity mapping signal is with a futuristic radio array on the lunar far-side, with the potential to detect a signal many orders of magnitude weaker than current or maximal constraints from other probes
Robust Chaos and the Continuity of Attractors
No full textAs the parameters of a map are varied an attractor may vary continuously in the Hausdorff metric. The purpose of this paper is to explore the continuation of chaotic attractors. We argue that this is not a helpful concept for smooth unimodal maps for which periodic windows fill parameter space densely, but that for many families of piecewise-smooth maps it provides a way to think about changing structures within parameter regions of robust chaos and form a stronger notion of robustness. We obtain conditions for the continuity of an attractor and demonstrate the results with coupled skew tent maps, the Lozi map, and the border-collision normal form
Galaxy Optical Variability of Virgo Cluster: New Tracer for Environmental Influences on Galaxies
No full textWe investigate the relationship between the optical variability of galaxies and their distances from the centre of the Virgo Cluster using Palomar Transient Factory data. We define the ratio between the standard deviation of the galaxy brightness and the mean value of the standard deviation as a measure of a galaxy’s optical variability. A sample of 814 Virgo galaxies with 230263 observations shows a monotonically decreasing trend of optical variability with increasing clustercentric distance. The variability level inside the cluster is 3.2σ higher than the level outside. We fit the variability with a linear function and find that the data reject a distance-independent model. We examine 217 background galaxies for comparison and find no significant trend in galaxy variability. We assess the relation with Monte Carlo simulation by rebuilding the brightness of each galaxy. The simulation shows a monotonically decreasing relation for member galaxy variability and a distance-independent relation for background galaxies. Our result is consistent with the theory that the cold gas flowing inwards the cluster centre fuels AGN activity. This work is a new implementation of the method using optical variability to investigate the relation between galaxies evolution and their environment
European Guidance from EHTG and ESCP for Lynch syndrome: an updated third edition of the “Mallorca Guidelines” based on Gene and Gender
No full textBackground Lynch syndrome (LS) is the most common genetic predisposition for hereditary cancer but remains under-diagnosed. Large prospective observational studies have recently increased understanding of the effectiveness of colonoscopy surveillance and the heterogeneity of cancer risk between genotypes. The need for gene- and gender-specific guidelines has been acknowledged. Method European Hereditary Tumour Group (EHTG) and European Society of Coloproctology (ESCP) developed a multidisciplinary working group consisting of surgeons, clinical and molecular geneticists, pathologists, epidemiologists, gastroenterologists, and patient representation to conduct a graded evidence review. The previous ‘Mallorca guideline’ format was used to revise the clinical guidance. Consensus for the guidance statements were acquired by three Delphi voting rounds. Results Recommendations for clinical and molecular identification of LS, surgical and endoscopic management of LS-associated colorectal cancer and preventive measures for cancer were produced. The emphasis was on surgical and gastroenterological aspects of the cancer spectrum. Manchester consensus guidelines for gynaecological management were endorsed. Executive and layperson summaries were provided. Conclusion The recommendations from the EHTG and ESCP for identification of LS patients, colorectal surveillance, surgical management of colorectal cancer, lifestyle and chemoprevention in LS that reached a consensus (>80%) are presented
Distributed Generalised Nash Equilibrium Seeking and Its Application to Femtocell Networks
No full textIn this paper, distributed algorithms are developed to search the generalised Nash equilibrium with global constraints. Relations between the variational inequality and the Nash equilibrium are investigated via the Karush-Kuhn-Tucher (KKT) optimal conditions, which provide the underlying principle for developing the distributed algorithms. Two time-varying consensus schemes are proposed for each agent to estimate the actions of others, by which a distributed framework is established. The algorithm with fixed gains is designed with certain system knowledge, while the adaptive algorithm is proposed to address the problem when the system parameters are not available. The asymptotic convergence to the Nash equilibrium is established through Lyapunov theory and the consensus theory. The power control problem in a femtocell network is formulated as a Nash game, and is solved by the proposed algorithms. Simulation results are provided to verify the effectiveness of the theoretical development
Lasting modulation of human cortical swallowing motor pathways following thermal tongue stimulation.
No full textPurpose: Thermal tactile oropharyngeal stimulation has been clinically used to facilitate swallowing initiation in dysphagic patients. We previously demonstrated that thermal stimulation applied to the oral cavity provokes an immediate excitability in pharyngeal motor cortex. The aim of the current study was to investigate whether thermal stimulation can produce longer lasting effects on the cortico-pharyngeal neural pathway. Material and Methods: Healthy volunteers (n=8/12) underwent baseline pharyngeal motor evoked potential (PMEP) measurements evoked by transcranial magnetic stimulation. In the first experiment, subjects received thermal stimulation alternating 30 s of 15 degrees Celsius (°C) and 36°C applied to the tongue surface for either 10 minutes, 5 minutes, or sham. In the second experiment, one of three intermittent thermal stimulus patterns was delivered; cold (alternating 30 s of 15 °C and 36°C), warm (continuous 36 °C) or hot (alternating 30 s of 45 °C and 36°C) for 10 minutes. In both experiments, PMEPs were re-measured every 15 minutes up to 60 minutes following thermal stimulation. Results: Repeated measures ANOVA for each stimulus time in the first experiment showed a significant increased change in PMEP amplitude at 30 minutes following only 10-minutes stimulation compared to sham (p < 0.05). In the second experiment, we found that cold stimulation was more effective than the other stimulation (p < 0.05) at increasing PMEP amplitudes. Conclusions: Ten minutes cold stimulation on the tongue can induce a delayed (30 min) increase in pharyngeal cortical excitability, providing a clinically useful therapeutic window for its application in dysphagic patients
The effect of a conditional cash transfer programme across the mental health distribution
No full textPoor mental health is a pressing global health problem, with high prevalence among poor populations from Low-Income Countries. Existing studies of conditional cash transfer effects on mental health have found positive effects. However, there is a gap in the literature on population wide effects of cash transfers on mental health and if and how these vary by the severity of mental illness. We use the Malawian Longitudinal Study of Family and Health containing 790 adult participants in the Malawi Incentive Programme, a year-long Randomised Controlled Trial. We estimate average and distributional quantile treatment effects and we examine how these effects vary by gender, HIV-status and usage of the cash transfer. We find that the cash transfer improves mental health on average by 0.1 of a standard deviation. The effect varies strongly along the mental health distribution, with a positive effect for individuals with worst mental health of about four times the size of the average effect. These improvements in mental health are associated with increases in consumption expenditures and expenditures related to economic productivity. Our results show that conditional cash transfers can improve adult mental health for the poor living in Low-Income Countries, particularly those with the worst mental health
Mechanical equilibrium operation integrated modelling of hybrid SOFC – GT systems: design analyses and off-design optimization
No full textA novel model has been built in this research integrating mechanical equilibrium operation, electrochemical reactions and other thermodynamic processes to gain insights into SOFC – GT hybrid systems in both energetic and operational aspects. To deliver the recommended SOFC pressure of 4- 7 bar, a centrifugal compressor of high compression ratio is employed, and the matching issues of turbomachinery are newly analyzed to account for the disruption of SOFCs to the operation of singleshaft gas turbines. The number of independent parameters decreases in hybrid system modelling when speed and flow compatibilities are contained to ensure turbomachinery running stably without acceleration or deceleration. Compared to conventional gas turbines, however, the coupling of SOFCs substantively introduces at least two independent variables to the flow compatibility equation, in which two of the unknown terms are essentially assigned by different air and fuel utilization. When the turbine is appropriately designed with pressure loss considerations, an electric efficiency of 48.0 % can be achieved by the simple system without surge risk of the compressor. Results also highlight the improvement effects of the coupling technology under off-design conditions. In ideal case, an electric efficiency of 44.4 % can still be achieved at 46 % designed power output
A Framework for Software Diversification with ISA Heterogeneity
No full textSoftware diversification is one of the most effective ways to defeat memory corruption based attacks. Traditional software diversification such as code randomization techniques diversifies program memory layout and makes it difficult for attackers to pinpoint the precise location of a target vulnerability. Some recent work in the architecture community use diverse ISA configurations to defeat code injection or code reuse attacks, showing that dynamically switching the ISA on which a program executes is a promising direction for future security systems. However, most of these work either remain in a simulation stage or require extra efforts to write program. In this paper, we propose HeterSec, a framework to secure applications utilizing a heterogeneous ISA setup composed of real world machines. HeterSec runs on top of commodity x86_64 and ARM64 machines and gives the process the illusion that it runs on a multi-ISA chip multiprocessor (CMP) machine. With HeterSec, a process can dynamically select its underlying ISA environment. Therefore, a protected process would be capable of hiding the instruction set on which it executed or detecting abnormal program behavior by comparing execution results step-by-step from multiple ISA-diversified instances. To demonstrate the effectiveness of such a software framework, we implemented HeterSec on Linux and showcased its deployability by running it on a pair of x86_64 and ARM64 servers, connected over InfiniBand. We then conducted two case studies with HeterSec. In the first case, we implemented a multi-ISA moving target defense (MTD) system, which introduces uncertainty at the instruction set level. In the second case, we implemented a multi-ISA-based multi-version execution (MVX) system. The evaluation results show that HeterSec brings security benefits through ISA diversification with a reasonable performance overhead
