4,156 research outputs found
Modulus Computational Entropy
The so-called {\em leakage-chain rule} is a very important tool used in many
security proofs. It gives an upper bound on the entropy loss of a random
variable in case the adversary who having already learned some random
variables correlated with , obtains some further
information about . Analogously to the information-theoretic
case, one might expect that also for the \emph{computational} variants of
entropy the loss depends only on the actual leakage, i.e. on .
Surprisingly, Krenn et al.\ have shown recently that for the most commonly used
definitions of computational entropy this holds only if the computational
quality of the entropy deteriorates exponentially in
. This means that the current standard definitions
of computational entropy do not allow to fully capture leakage that occurred
"in the past", which severely limits the applicability of this notion.
As a remedy for this problem we propose a slightly stronger definition of the
computational entropy, which we call the \emph{modulus computational entropy},
and use it as a technical tool that allows us to prove a desired chain rule
that depends only on the actual leakage and not on its history. Moreover, we
show that the modulus computational entropy unifies other,sometimes seemingly
unrelated, notions already studied in the literature in the context of
information leakage and chain rules. Our results indicate that the modulus
entropy is, up to now, the weakest restriction that guarantees that the chain
rule for the computational entropy works. As an example of application we
demonstrate a few interesting cases where our restricted definition is
fulfilled and the chain rule holds.Comment: Accepted at ICTS 201
Acupuncture and related therapies for treating irritable bowel syndrome: overview of systematic reviews and network meta-analysis
© The Author(s), 2019. Background: An overview of systematic reviews (SRs) and a network meta-analysis (NMA) were conducted to evaluate the comparative effectiveness of acupuncture and related therapies used either alone, or as an add-on to other irritable bowel syndrome (IBS) treatments. Methods: A total of eight international and Chinese databases were searched for SRs of randomized controlled trials (RCTs). The methodological quality of SRs was appraised using the AMSTAR instrument. From the included SRs, data from RCTs were extracted for the random-effect pairwise meta-analyses. An NMA was used to evaluate the comparative effectiveness of different treatment options. The risk of bias among included RCTs was assessed using the Cochrane risk of bias tool. Results: From 15 SRs of mediocre quality, 27 eligible RCTs (n = 2141) were included but none performed proper blinding. Results from pairwise meta-analysis showed that both needle acupuncture and electroacupuncture were superior in improving global IBS symptoms when compared with pinaverium bromide. NMA results showed needle acupuncture plus Geshanxiaoyao formula had the highest probability of being the best option for improving global IBS symptoms among 14 included treatment options, but a slight inconsistency exists. Conclusion: The risk of bias and NMA inconsistency among included trials limited the trustworthiness of the conclusion. Patients who did not respond well to first-line conventional therapies or antidepressants may consider acupuncture as an alternative. Future trials should investigate the potential of (1) acupuncture as an add-on to antidepressants and (2) the combined effect of Chinese herbs and acupuncture, which is the norm of routine Chinese medicine practice
Mapping the structure of Borneo's tropical forests across a degradation gradient
South East Asia has the highest rate of lowland forest loss of any tropical region, with logging and deforestation for conversion to plantation agriculture being flagged as the most urgent threats. Detecting and mapping logging impacts on forest structure is a primary conservation concern, as these impacts feed through to changes in biodiversity and ecosystem functions. Here, we test whether high-spatial resolution satellite remote sensing can be used to map the responses of aboveground live tree biomass (AGB), canopy leaf area index (LAI) and fractional vegetation cover (FCover) to selective logging and deforestation in Malaysian Borneo. We measured these attributes in permanent vegetation plots in rainforest and oil palm plantations across the degradation landscape of the Stability of Altered Forest Ecosystems project. We found significant mathematical relationships between field-measured structure and satellite-derived spectral and texture information, explaining up to 62% of variation in biophysical structure across forest and oil palm plots. These relationships held at different aggregation levels from plots to forest disturbance types and oil palms allowing us to map aboveground biomass and canopy structure across the degradation landscape. The maps reveal considerable spatial variation in the impacts of previous logging, a pattern that was less clear when considering field data alone. Up-scaled maps revealed a pronounced decline in aboveground live tree biomass with increasing disturbance, impacts which are also clearly visible in the field data even a decade after logging. Field data demonstrate a rapid recovery in forest canopy structure with the canopy recovering to pre-disturbance levels a decade after logging. Yet, up-scaled maps show that both LAI and FCover are still reduced in logged compared to primary forest stands and markedly lower in oil palm stands. While uncertainties remain, these maps can now be utilised to identify conservation win–wins, especially when combining them with ongoing biodiversity surveys and measurements of carbon sequestration, hydrological cycles and microclimate
Intramuscular myxoid lipoma in the proximal forearm presenting as an olecranon mass with superficial radial nerve palsy: a case report
<p>Abstract</p> <p>Background</p> <p>Extremity lipomas may occur in any location, including the proximal forearm. We describe a case of a patient with an intramuscular lipoma presenting as an unusual posterior elbow mass.</p> <p>Case presentation</p> <p>We discuss the case of a 57-year-old Caucasian man who presented with a tender, posterior elbow mass initially diagnosed as chronic olecranon bursitis. A minor sensory disturbance in the distribution of the superficial radial nerve was initially thought to be unrelated, but was likely caused by mass effect from the lipoma. No pre-operative advanced imaging was obtained because the diagnosis was felt to have already been made. At the time of surgery, a fatty mass originating in the volar forearm muscles was found to have breached the dorsal forearm fascia and displaced the olecranon bursa. Tissue diagnosis was made by histopathology as a myxoid lipoma with no aggressive features. Post-operative recovery was uneventful.</p> <p>Conclusion</p> <p>We present a case of an unusual elbow mass presenting with symptoms consistent with chronic olecranon bursitis, a relatively common condition. The only unexplained pre-operative finding was the non-specific finding of a transient superficial radial nerve deficit. We remind clinicians to be cautious when diagnosing soft tissue masses in the extremities when unexplained physical findings are present.</p
Ocean acidification affects fish spawning but not paternity at CO2 seeps
Fish exhibit impaired sensory function and altered behaviour at levels of ocean acidification expected to occur owing to anthropogenic carbon dioxide emissions during this century. We provide the first evidence of the effects of ocean acidification on reproductive behaviour of fish in the wild. Satellite and sneaker male ocellated wrasse (Symphodus ocellatus) compete to fertilize eggs guarded by dominant nesting males. Key mating behaviours such as dominant male courtship and nest defence did not differ between sites with ambient versus elevated CO2 concentrations. Dominant males did, however, experience significantly lower rates of pair spawning at elevated CO2 levels. Despite the higher risk of sperm competition found at elevated CO2, we also found a trend of lower satellite and sneaker male paternity at elevated CO2. Given the importance of fish for food security and ecosystem stability, this study highlights the need for targeted research into the effects of rising CO2 levels on patterns of reproduction in wild fish
Altered cortical brain activity in end stage liver disease assessed by multi-channel near-infrared spectroscopy: associations with delirium
VEZF1 elements mediate protection from DNA methylation
There is growing consensus that genome organization and long-range gene regulation involves partitioning of the genome into domains of distinct epigenetic chromatin states. Chromatin insulator or barrier elements are key components of these processes as they can establish boundaries between chromatin states. The ability of elements such as the paradigm β-globin HS4 insulator to block the range of enhancers or the spread of repressive histone modifications is well established. Here we have addressed the hypothesis that a barrier element in vertebrates should be capable of defending a gene from silencing by DNA methylation. Using an established stable reporter gene system, we find that HS4 acts specifically to protect a gene promoter from de novo DNA methylation. Notably, protection from methylation can occur in the absence of histone acetylation or transcription. There is a division of labor at HS4; the sequences that mediate protection from methylation are separable from those that mediate CTCF-dependent enhancer blocking and USF-dependent histone modification recruitment. The zinc finger protein VEZF1 was purified as the factor that specifically interacts with the methylation protection elements. VEZF1 is a candidate CpG island protection factor as the G-rich sequences bound by VEZF1 are frequently found at CpG island promoters. Indeed, we show that VEZF1 elements are sufficient to mediate demethylation and protection of the APRT CpG island promoter from DNA methylation. We propose that many barrier elements in vertebrates will prevent DNA methylation in addition to blocking the propagation of repressive histone modifications, as either process is sufficient to direct the establishment of an epigenetically stable silent chromatin stat
Voxel-wise comparisons of cellular microstructure and diffusion-MRI in mouse hippocampus using 3D Bridging of Optically-clear histology with Neuroimaging Data (3D-BOND)
A key challenge in medical imaging is determining a precise correspondence between image properties and tissue microstructure. This comparison is hindered by disparate scales and resolutions between medical imaging and histology. We present a new technique, 3D Bridging of Optically-clear histology with Neuroimaging Data (3D-BOND), for registering medical images with 3D histology to overcome these limitations. Ex vivo 120 × 120 × 200 μm resolution diffusion-MRI (dMRI) data was acquired at 7 T from adult C57Bl/6 mouse hippocampus. Tissue was then optically cleared using CLARITY and stained with cellular markers and confocal microscopy used to produce high-resolution images of the 3D-tissue microstructure. For each sample, a dense array of hippocampal landmarks was used to drive registration between upsampled dMRI data and the corresponding confocal images. The cell population in each MRI voxel was determined within hippocampal subregions and compared to MRI-derived metrics. 3D-BOND provided robust voxel-wise, cellular correlates of dMRI data. CA1 pyramidal and dentate gyrus granular layers had significantly different mean diffusivity (p > 0.001), which was related to microstructural features. Overall, mean and radial diffusivity correlated with cell and axon density and fractional anisotropy with astrocyte density, while apparent fibre density correlated negatively with axon density. Astrocytes, axons and blood vessels correlated to tensor orientation
Control and Characterization of Individual Grains and Grain Boundaries in Graphene Grown by Chemical Vapor Deposition
The strong interest in graphene has motivated the scalable production of high
quality graphene and graphene devices. Since large-scale graphene films
synthesized to date are typically polycrystalline, it is important to
characterize and control grain boundaries, generally believed to degrade
graphene quality. Here we study single-crystal graphene grains synthesized by
ambient CVD on polycrystalline Cu, and show how individual boundaries between
coalescing grains affect graphene's electronic properties. The graphene grains
show no definite epitaxial relationship with the Cu substrate, and can cross Cu
grain boundaries. The edges of these grains are found to be predominantly
parallel to zigzag directions. We show that grain boundaries give a significant
Raman "D" peak, impede electrical transport, and induce prominent weak
localization indicative of intervalley scattering in graphene. Finally, we
demonstrate an approach using pre-patterned growth seeds to control graphene
nucleation, opening a route towards scalable fabrication of single-crystal
graphene devices without grain boundaries.Comment: New version with additional data. Accepted by Nature Material
Baseline Demographics, Comorbidities, Treatment Patterns and Burden of Atopic Dermatitis in Adults and Adolescents from the GLOBOSTAD Long-Term Observational Study
Introduction: Insights into real-world treatment of atopic dermatitis (AD) are relevant to clinical decision making. The aim of this analysis was to characterize patients who receive dupilumab for AD in a real-world setting.
Methods: The GLOBOSTAD registry is an ongoing, longitudinal, prospective, observational study of patients with AD who receive dupilumab according to country-specific prescribing information. We report baseline characteristics, comorbidities and treatment patterns for patients enrolled from July 11, 2019 to March 31, 2022. Analyses are descriptive; no formal statistical comparisons were performed.
Results: Nine hundred fifty-two adults and adolescents were enrolled in GLOBOSTAD. Patients had a high disease burden before starting dupilumab: (mean [standard deviation]) percent body surface area affected (44.8 [24.42]), Eczema Area and Severity Index total score (24.8 [12.95]), SCORing Atopic Dermatitis total score (60.5 [16.34]), Patient-Oriented Eczema Measure total score (19.7 [6.37]) and Dermatology Life Quality Index total score (13.7 [7.02]). Overall, 741 (77.8%) patients reported ≥ 1 type 2 inflammatory comorbidities, most frequently allergic rhinitis (492 [51.7%]), asthma (323 [33.9%]), food allergy (294 [30.9%]) or another allergy (274 [28.8%]). In the previous 12 months, 310 (32.6%) patients had received systemic non-steroidal immunosuppressants and 169 (17.8%) systemic corticosteroids; 449 (47.2%) had received topical corticosteroids, most commonly potent topical corticosteroids; 141 (14.8%) had received topical calcineurin inhibitors and 32 (3.4%) ultraviolet therapy. Most (713 [74.9%]) patients started dupilumab because of prior treatment failure.
Conclusion: Patients enrolled in GLOBOSTAD demonstrated considerable multidimensional burden of disease across AD signs, symptoms and quality of life despite previous use of systemic and non-systemic AD treatments
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