1,830 research outputs found
Detection of encrypted cryptomining malware connections with machine and deep learning
Nowadays, malware has become an epidemic problem. Among the attacks exploiting the computer resources of victims, one that has become usual is related to the massive amounts of computational resources needed for digital currency cryptomining. Cybercriminals steal computer resources from victims, associating these resources to the crypto-currency mining pools they benefit from. This research work focuses on offering a solution for detecting such abusive cryptomining activity, just by means of passive network monitoring. To this end, we identify a new set of highly relevant network flow features to be used jointly with a rich set of machine and deep-learning models for real-time cryptomining flow detection. We deployed a complex and realistic cryptomining scenario for training and testing machine and deep learning models, in which clients interact with real servers across the Internet and use encrypted connections. A complete set of experiments were carried out to demonstrate that, using a combination of these highly informative features with complex machine learning models, cryptomining attacks can be detected on the wire with telco-grade precision and accuracy, even if the traffic is encrypted
Modelling and analysis of influenza A (H1N1) on networks
Network modelling is a useful tool for studying the transmission of H1N1 in China, capturing the main features of the spread of H1N1. The paper calculates the basic reproduction number and studies the effects of various immunization schemes. The final size relation is derived for the network epidemic model. While a uniform, mass-immunization strategy helps control the prevalence, a targeted immunization strategy focusing on specific groups with given connectivity may better control an epidemic
Comparison of the TBARS Assay and BODIPY C11 Probes for Assessing Lipid Peroxidation in Red Deer Spermatozoa
P. 360-368Several methods are used to measure lipid peroxidation (LPO) in spermatozoa. The objective of this study was comparing the thiobarbituric acid reactive species (TBARS) method and the BODIPY 581/591 C11 (B581) and BODIPY 665/676 C11 (B665) fluorescent probes to measure induced peroxidative damage in thawed epididymal spermatozoa from Iberian red deer. Samples from three males were thawed, pooled, diluted in PBS, incubated at room temperature and assessed at 0, 3, 6 and 24 h under different experimental conditions: Control, hydrogen peroxide (H2O2) 0.1 mm or 1 mm, or tert‐butyl hydroperoxide (TBH) 0.1 mm or 1 mm. LPO was assessed by the TBARS assay [malondialdehyde (MDA) detection] and by the fluorescence probes B581 and B665 (microplate fluorimeter and flow cytometry). Increasing MDA levels were only detectable at 1 mm of TBH or H2O2. Both fluorescence probes, measured with fluorometer, detected significant increases of LPO with time in all treatments, except Control. Flow cytometry allowed for higher sensitivity, with both probes showing a significant linear relationship of increasing LPO with time for all oxidizing treatments (p < 0.001). All methods showed a good agreement, except TBARS, and flow cytometry showed the highest repeatability. Our results show that both B581 and B665 might be used for LPO analysis in Iberian red deer epididymal spermatozoa, together with fluorometry or flow cytometry. Yet, the TBARS method offered comparatively limited sensitivity, and further research must determine the source of that limitation.S
THE COST STRUCTURE OF MICROFINANCE INSTITUTIONS IN EASTERN EUROPE AND CENTRAL ASIA
Microfinance institutions are important, particularly in developing countries, because they expand the frontier of financial intermediation by providing loans to those traditionally excluded from formal financial markets. This paper presents the first systematic statistical examination of the performance of MFIs operating in Eastern Europe and Central Asia. A cost function is estimated for MFIs in the region from 1999-2004. First, the presence of subsidies is found to be associated with higher MFI costs. When output is measured as the number of loans made, we find that MFIs become more efficient over time and that MFIs involved in the provision of group loans and loans to women have lower costs. However, when output is measured as volume of loans rather than their number, this last finding is reversed. This may be due to the fact that such loans are smaller in size; thus for a given volume more loans must be made.http://deepblue.lib.umich.edu/bitstream/2027.42/40195/3/wp809.pd
Correlating activity and defects in (photo)electrocatalysts using in-situ transient optical microscopy
(Photo)electrocatalysts capture sunlight and use it to drive chemical
reactions such as water splitting to produce H2. A major factor limiting
photocatalyst development is their large heterogeneity which spatially
modulates reactivity and precludes establishing robust structure-function
relationships. To make such links requires simultaneously probing of the
electrochemical environment at microscopic length scales (nm to um) and broad
timescales (ns to s). Here, we address this challenge by developing and
applying in-situ steady-state and transient optical microscopies to directly
map and correlate local electrochemical activity with hole lifetimes, oxygen
vacancy concentration and the photoelectrodes crystal structure. Using this
combined approach alongside spatially resolved X-Ray absorption measurements,
we study microstructural and point defects in prototypical hematite (Fe2O3)
photoanodes. We demonstrate that regions of Fe2O3, adjacent to microstructural
cracks have a better photoelectrochemical response and reduced back electron
recombination due to an optimal oxide vacancy concentration, with the film
thickness and carbon impurities also dramatically influencing activity in a
complex manner. Our work highlights the importance of microscopic mapping to
understand activity and the impact of defects in even, seemingly, homogeneous
solid-state metal oxide photoelectrodes
Yeast thioredoxin reductase Trr1p controls TORC1-regulated processes
The thioredoxin system plays a predominant role in the control of cellular redox status. Thioredoxin reductase fuels the system with reducing power in the form of NADPH. The TORC1 complex promotes growth and protein synthesis when nutrients, particularly amino acids, are abundant. It also represses catabolic processes, like autophagy, which are activated during starvation. We analyzed the impact of yeast cytosolic thioredoxin reductase TRR1 deletion under different environmental conditions. It shortens chronological life span and reduces growth in grape juice fermentation. TRR1 deletion has a global impact on metabolism during fermentation. As expected, it reduces oxidative stress tolerance, but a compensatory response is triggered, with catalase and glutathione increasing. Unexpectedly, TRR1 deletion causes sensitivity to the inhibitors of the TORC1 pathway, such as rapamycin. This correlates with low Tor2p kinase levels and indicates a direct role of Trr1p in its stability. Markers of TORC1 activity, however, suggest increased TORC1 activity. The autophagy caused by nitrogen starvation is reduced in the trr1Δ mutant. Ribosomal protein Rsp6p is dephosphorylated in the presence of rapamycin. This dephosphorylation diminishes in the TRR1 deletion strain. These results show a complex network of interactions between thioredoxin reductase Trr1p and the processes controlled by TOR
Selenium and impaired physical function in US and Spanish older adults
Background: Selenium (Se) is a trace element with a narrow safety margin.
Objectives: To evaluate the cross-sectional and longitudinal dose-response association between Se exposure and
measures of impaired physical function and disability in older adults.
Design: NHANES 2011–2014 cross-sectional (US, n = 1733, age ≥60 years) and Seniors-ENRICA-2 2017–2019
cross-sectional and longitudinal (Spain, n = 2548 and 1741, respectively, age ≥65 years) data were analyzed.
Whole blood and serum Se levels were measured using inductively coupled plasma-mass spectrometry. Lowerextremity
performance was assessed with the Short Physical Performance Battery, and muscle weakness with
a dynamometer. Incident mobility and agility limitations, and disability in instrumental activities of daily living
(IADL) were ascertained with standardized questionnaires. Analyses were adjusted for relevant confounders,
including physical activity. Results across studies were pooled using random-effects meta-analysis.
Results: Meta-analyzed odds ratios (95% confidence interval) per log2 increase in whole blood Se were 0.54
(0.32; 0.76) for weakness, 0.59 (0.34; 0.83) for impaired lower-extremity performance, 0.48 (0.31; 0.68) for
mobility limitations, 0.71 (0.45; 0.97) for agility limitations, and 0.34 (0.12; 0.56) for disability in at least one
IADL. Analyses for serum Se in NHANES showed similar results. Findings suggest the inverse association with
grip strength is progressive below 140 μg/L (p-value for non-linear trend in the Seniors-ENRICA-2 study = 0.13),
and above 140 μg/L (p-value for non-linear trend in NHANES = 0.11). In the Seniors-ENRICA-2 cohort, with a
2.2 year follow-up period, a doubling in baseline Se levels were associated with a lower incidence of weakness
[odds ratio (95% confidence interval): 0.45 (0.22; 0.91)], impaired lower-extremity performance [0.63 (0.32;
1.23)], mobility [0.43 (0.21; 0.91)] and agility [0.38 (0.18; 0.78)] limitations.
Discussion: In US and Spanish older adults, Se concentrations were inversely associated with physical function
limitations. Further studies are needed to elucidate underlying mechanisms.Instituto de Salud Carlos III
European Commission
PI18/287
16/609State Secretary of R + D + I
PID2019-108973RB-C21/C22European Social Fund (ESF)
European Commissio
Early prevention of diabetes microvascular complications in people with hyperglycaemia in Europe. ePREDICE randomized trial. Study protocol, recruitment and selected baseline data
Objectives To assess the effects of early management of hyperglycaemia with antidiabetic drugs plus lifestyle intervention compared with lifestyle alone, on microvascular function in adults with pre-diabetes. Methods Trial design: International, multicenter, randomised, partially double-blind, placebo-controlled, clinical trial. Participants Males and females aged 45-74 years with IFG, IGT or IFG+IGT, recruited from primary care centres in Australia, Austria, Bulgaria, Greece, Kuwait, Poland, Serbia, Spain and Turkey. Intervention Participants were randomized to placebo; metformin 1.700 mg/day; linagliptin 5 mg/day or fixed-dose combination of linagliptin/metformin. All patients were enrolled in a lifestyle intervention program (diet and physical activity). Drug intervention will last 2 years. Primary Outcome: Composite end-point of diabetic retinopathy estimated by the Early Treatment Diabetic Retinopathy Study Score, urinary albumin to creatinine ratio, and skin conductance in feet estimated by the sudomotor index. Secondary outcomes in a subsample include insulin sensitivity, beta-cell function, biomarkers of inflammation and fatty liver disease, quality of life, cognitive function, depressive symptoms and endothelial function. Results One thousand three hundred ninety one individuals with hyperglycaemia were assessed for eligibility, 424 excluded after screening, 967 allocated to placebo, metformin, linagliptin or to fixed-dose combination of metformin + linagliptin. A total of 809 people (91.1%) accepted and initiated the assigned treatment. Study sample after randomization was well balanced among the four groups. No statistical differences for the main risk factors analysed were observed between those accepting or rejecting treatment initiation. At baseline prevalence of diabetic retinopathy was 4.2%, severe neuropathy 5.3% and nephropathy 5.7%. Conclusions ePREDICE is the first -randomized clinical trial with the aim to assess effects of different interventions (lifestyle and pharmacological) on microvascular function in people with prediabetes. The trial will provide novel data on lifestyle modification combined with glucose lowering drugs for the prevention of early microvascular complications and diabetes
NOMAD spectrometer on the ExoMars trace gas orbiter mission: part 2—design, manufacturing, and testing of the ultraviolet and visible channel
NOMAD is a spectrometer suite on board the ESA/Roscosmos ExoMars Trace Gas Orbiter, which launched in March 2016. NOMAD consists of two infrared channels and one ultraviolet and visible channel, allowing the instrument to perform observations quasi-constantly, by taking nadir measurements at the day- and night-side, and during solar occultations. Here, in part 2 of a linked study, we describe the design, manufacturing, and testing of the ultraviolet and visible spectrometer channel called UVIS. We focus upon the optical design and working principle where two telescopes are coupled to a single grating spectrometer using a selector mechanism
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