Miracle-dz/UniFAR-FTUs huggingface dataset:
Markov chain methods for small-set expansion

Consider a finite irreducible Markov chain with invariant distribution $\pi$. We use the inner product induced by $\pi$ and the associated heat operator to simplify and generalize some results related to graph partitioning and the small-set expansion problem. For example, Steurer showed a tight connection between the number of small eigenvalues of a graph's Laplacian and the expansion of small sets in that graph. We give a simplified proof which generalizes to the nonregular, directed case. This result implies an approximation algorithm for an "analytic" version of the Small-Set Expansion Problem, which, in turn, immediately gives an approximation algorithm for Small-Set Expansion. We also give a simpler proof of a lower bound on the probability that a random walk stays within a set; this result was used in some recent works on finding small sparse cuts.
The Role of the Multidrug Resistance Protein-1 in Modulation of Endothelial Cell Oxidative Stress

Glutathione (GSH) is the major source of intracellular sulfhydryl groups. Oxidized GSH (GSSG) can be recycled to GSH by the GSH reductase or exported from the cell. The mechanism by which GSSG is exported and the consequence of its export from endothelial cells has not been defined previously. We found that human endothelial cells express the multidrug resistance protein-1 (MRP1) and use this as their major exporter of GSSG. Oscillatory shear stress, which is known to stimulate endothelial cell production of reactive oxygen species, decreased intracellular GSH. In contrast, laminar shear significantly increased intracellular GSH. Oscillatory shear also caused a robust export of GSSG that was prevented by the MRP1 inhibitor MK571 and by MRP1 small interfering RNA. MRP1 inhibition prevented the decline in intracellular GSH, preserved the intracellular GSH Nernst potential, and reduced apoptosis caused by oscillatory shear. In aortas of hypertensive mice, endothelial disulfide export was doubled, and this was prevented by MK571 and was not observed in aortas of hypertensive MRP1−/− mice. Further, the altered endothelium-dependent vasodilatation caused by hypertension was ameliorated in MRP1−/− mice. GSSG export by MRP1 leads to a perturbation of endothelial redox state and ultimately endothelial cell apoptosis. Endothelial MRP1 may provide a novel therapeutic target for prevention of vascular disease.
New functions of Müller cells

Müller cells, the major type of glial cells in the retina, are responsible for the homeostatic and metabolic support of retinal neurons. By mediating transcellular ion, water, and bicarbonate transport, Müller cells control the composition of the extracellular space fluid. Müller cells provide trophic and anti‐oxidative support of photoreceptors and neurons and regulate the tightness of the blood‐retinal barrier. By the uptake of glutamate, Müller cells are more directly involved in the regulation of the synaptic activity in the inner retina. This review gives a survey of recently discoved new functions of Müller cells. Müller cells are living optical fibers that guide light through the inner retinal tissue. Thereby they enhance the signal/noise ratio by minimizing intraretinal light scattering and conserve the spatial distribution of light patterns in the propagating image. Müller cells act as soft, compliant embedding for neurons, protecting them in case of mechanical trauma, and also as soft substrate required for neurite growth and neuronal plasticity. Müller cells release neuroactive signaling molecules which modulate neuronal activity, are implicated in the mediation of neurovascular coupling, and mediate the homeostasis of the extracellular space volume under hypoosmotic conditions which are a characteristic of intense neuronal activity. Under pathological conditions, a subset of Müller cells may differentiate to neural progenitor/stem cells which regenerate lost photoreceptors and neurons. Increasing knowledge of Müller cell function and responses in the normal and diseased retina will have great impact for the development of new therapeutic approaches for retinal diseases.
Comparing Events Coverage in Online News and Social Media: The Case of Climate Change

Social media is becoming more and more integrated in the distribution and consumption of news. How is news in social media different from mainstream news? This paper presents a comparative analysis covering a span of 17 months and hundreds of news events, using a method that combines automatic and manual annotations. We focus on climate change, a topic that is frequently present in the news through a number of arguments, from current practices and causes (e.g. fracking, CO2 emissions) to consequences and solutions (e.g. extreme weather, electric cars). The coverage that these different aspects receive is often dependent on how they are framed---typically by mainstream media. Yet, evidence suggests an existing gap between what the news media publishes online and what the general public shares in social media. Through the analysis of a series of events, including awareness campaigns, natural disasters, governmental meetings and publications, among others, we uncover differences in terms of the triggers, actions, and news values that are prevalent in both types of media. This methodology can be extended to other important topics present in the news.
The X‐ray virial relations for relaxed lensing clusters observed with Chandra

We examine the relations linking mass, X-ray temperature and bolometric luminosity for a sample of luminous, relatively relaxed clusters of galaxies observed with the Chandra Observatory, for which independent confirmation of the mass results is available from gravitational lensing studies. Within radii corresponding to a fixed overdensity with respect to the critical density at the redshifts of the clusters, the observed temperature profiles, scaled in units of T2500 and r2500, exhibit an approximately universal form which rises within and then remains approximately constant out to r2500. We obtain best-fitting slopes for the mass–temperature and temperature–luminosity relations consistent with the predictions from simple scaling arguments i.e. and , respectively. We confirm the presence of a systematic offset of ∼40 per cent between the normalizations of the observed and predicted mass–temperature relations for both SCDM and ΛCDM cosmologies.
Hagfish slime exudate stabilization and its effect on slime formation and functionality

ABSTRACT Hagfish produce vast amounts of slime when under attack. The slime is the most dilute hydrogel known to date, and is a highly interesting material for biomaterial research. It forms from a glandular secrete, called exudate, which deploys upon contact with seawater. To study slime formation ex vivo and to characterize its material properties, stabilization of the sensitive slime exudate is crucial. In this study, we compared the two main stabilization methods, dispersion in high osmolarity citrate/PIPES (CP) buffer and immersion in oil, and tested the influence of time, temperature and pH on the stability of the exudate and functionality of the slime. Using water retention measurements to assess slime functionality, we found that CP buffer and oil preserved the exudate within the first 5 hours without loss of functionality. For longer storage times, slime functionality decreased for both stabilization methods, for which the breakdown mechanisms differed. Stabilization in oil likely favored temperature-sensitive osmotic-driven swelling and rupture of the mucin vesicles, causing the exudate to gel and clump. Extended storage in CP buffer resulted in an inhibited unraveling of skeins. We suggest that a water soluble protein glue, which mediates skein unraveling in functional skeins, denatures and gradually becomes insoluble during storage in CP buffer. The breakdown was accentuated when the pH of the CP buffer was raised from pH 6.7 to pH 8.5, probably caused by increased denaturation of the protein glue or by inferior vesicle stabilization. However, when fresh exudate was mixed into seawater or phosphate buffer at pH 6-9, slime functionality was not affected, showing pH insensitivity of the slime formation around a neutral pH. These insights on hagfish exudate stabilization mechanisms will support hagfish slime research at a fundamental level, and contribute to resolve the complex mechanisms of skein unraveling and slime formation. Summary: Loss of functionality of hagfish slime exudate during storage is driven by mucin vesicle rupture when stabilized in oil and by gradually inhibited skein unraveling when stabilized in buffer.
On the structure and dynamics of Ellerman bombs - Detailed study of three events and modelling of Hα

Aims. We study the structure and dynamics of three Ellerman bombs (EBs) observed in an evolving active region. Methods. The active region NOAA 11271 was observed with the Vacuum Tower Telescope at Observatorio del Teide/Tenerife on August 18, 2011. We used the two-dimensional Triple Etalon SOlar Spectrometer (TESOS) to obtain time sequences of the active region and of EBs in Hα at a cadence of 15 s. Simultaneously, we obtained full Stokes profiles with the Tenerife Infrared Polarimeter (TIP II) in the two magnetically sensitive Fe i infrared lines (IR) at 1.56 μ, scanning spatial sections of the area with cadences of 28−46 s. The Hα data were reconstructed with speckle methods to study the evolution of the atmospheric stratification. Two methods were used to extract magnetic field information from the IR Stokes profiles: 1) fitting of the (Q,U,V) profiles by Gaussians; and 2) applying the Milne-Eddington approximation, assuming two separate magnetic structures in the resolution element and fitting by trial and error some profiles from the EB areas. Data from SDO-HMI and -AIA were also used. We performed two-dimensional (2D) non-LTE radiative transfer calculations of Hα in parameterised models of EBs. Results. The three EBs studied in detail occurred in a complex active region near sunspots. They were very bright with a factor of 1.5–2.8 brighter than the nearby area. They lived for 1/2 h and longer. They were related to broadband faculae, but the latter were not the brightest features in the field of view. The EBs occurred in magnetic field configurations with opposite polarity close together. One EB was located at the outskirts of a penumbra of a complex sunspot and showed repeated “flaring” in SDO-AIA data. Another was close to a strong field patch and moved into this during the end of its lifetime. The third EB showed clear changes of field structure during the time it was observed. We obtained from the 2D modelling that heating and increase in Hα opacity are likely to occur at heights of 300–800 km. Line shifts and asymmetries can well be reproduced by velocities at these heights and also at much larger heights. Conclusions. The three EBs occurred at sites with magnetic fields of opposite polarity, which were likely the cause of the Hα brightening upon reconnection.
Learning with queries but incomplete information (extended abstract)

We investigate learning with membership and equivalence queries assuming that the information provided to the learner is incomplete. By incomplete we mean that some of the membership queries may be answered by “I don't know. ” This model is a worst-case version of the incomplete membership query model of Angluin and Slonim. It attempts to model practical learning situations, including an experiment of Lang and Baum that we describe, where the teacher may be unable to answer reliably some queries that are critical for the learning algorithm. We present algorithms to learn monotone k-term DNF with membership queries only, and to learn monotone DNF with membership and equivalence queries. Compared to the complete information case, the query complexity increases by an additive term linear in the number of “I don't know” answers received. We also observe that the blowup in the number of queries can in general be exponential for both our new model and the incomplete membership model.
Perseverative Behavior and Adaptive Control in Older Adults: Performance Monitoring, Rule Induction, and Set Shifting

Older adults, like patients with dorsolateral frontal lobe lesions, have been shown to be progressively susceptible to errors of perseveration in the Wisconsin Card Sorting Test (WCST). This deficit may result from several types of endogenous adaptive control abilities. First, to enable behavioral modifications in response to sudden changes in task demands, one has to consider and evaluate the possible alternative categorization rules and select one for further testing (rule induction). Second, to perform the required shift appropriately, one should suppress the no-longer relevant task set and replace it by an appropriate new one (set shifting). Third, however, proper application of rule-induction and set-shifting abilities requires the ability to monitor and interpret task cues and feedback signals appropriately to guide behavior and to recognize the need to apply rule-shift operations (performance monitoring). To explore the extent to which these different endogenous adaptive control abilities are differentially sensitive to the effect of aging, young and older adults were tested in two experiments using WCST-like tasks. From the finding that older adults were not able to capitalize on explicit shift cues (either nonspecific or specific) the inference can be drawn that basic set-shifting abilities, rather than rule-induction or performance-monitoring abilities, were the primary factor responsible for the increased tendency to perseverate as adults grow into senescence.
Hexachlorophene Is a Potent KCNQ1/KCNE1 Potassium Channel Activator Which Rescues LQTs Mutants

The voltage-gated KCNQ1 potassium channel is expressed in cardiac tissues, and coassembly of KCNQ1 with an auxiliary KCNE1 subunit mediates a slowly activating current that accelerates the repolarization of action potential in cardiomyocytes. Mutations of KCNQ1 genes that result in reduction or loss of channel activity cause prolongation of repolarization during action potential, thereby causing long QT syndrome (LQTs). Small molecule activators of KCNQ1/KCNE1 are useful both for understanding the mechanism of the complex activity and for developing therapeutics for LQTs. In this study we report that hexachlorophene (HCP), the active component of the topical anti-infective prescription drug pHisoHex, is a KCNQ1/KCNE1 activator. HCP potently increases the current amplitude of KCNQ1/KCNE1 expressed by stabilizing the channel in an open state with an EC50 of 4.61±1.29 μM. Further studies in cardiomyocytes showed that HCP significantly shortens the action potential duration at 1 μM. In addition, HCP is capable of rescuing the loss of function of the LQTs mutants caused by either impaired activation gating or phosphatidylinositol-4,5-bisphosphate (PIP2) binding affinity. Our results indicate HCP is a novel KCNQ1/KCNE1 activator and may be a useful tool compound for the development of LQTs therapeutics.
Anti Oxidative, Anti Peroxidative and Hepatoprotective Potential of Phyllanthus amarus Against Anti Tb Drugs

The liver plays an astonishing array of vital functions in the maintenance and perform‐ ance of the body. Additionally, it is also handling the metabolism and excretion of drugs and other xenobiotics from the body thereby providing protection against foreign substan‐ ces by detoxifying and eliminating them (saleem et al., 2010). Large numbers of xenobiot‐ ics are reported to be potentially hepatotoxic. Free radicals generated from the xenobiotic metabolism can induce lesions of the liver and react with the basic cellular constituents such as proteins, lipids, RNA and DNA (Ajith et al., 2007). A growing international health concern is Tuberculosis caused by Mycobacterium tuberculosis (Abdelaal et al., 2009). India is the highest TB burden country accounting for one fifth (21%) of the global incidence (WHO, 2010). The first line anti-tuberculosis drugs isoniazid (INH), rifampicin (RIF), pyrazina‐ mide (PZA) and Ethambutol(ETH)continues to be the effective drugs in the treatment of tuberculosis, however, the use of these drugs is associated with toxic reactions in tissues, particularly in the liver, leading to hepatitis (Eminzade et al., 2008). This is one of the most serious adverse effects of anti-tuberculosis drugs (ATD). Liver injury or liver dysfunction is a major health problem that challenges not only health care professionals but also the pharmaceutical industry and drug regulatory agencies (saleem et al., 2010). It has great capacity to detoxify and synthesize useful substances, and therefore damage to the liver has grave consequences (Devaraj et al., 2011). Currently, there is no effective treatment against ATD induced hepatic damage. Plants are an important component of the health
Aryl Hydrocarbon Receptor Repressor and TiPARP (ARTD14) Use Similar, but also Distinct Mechanisms to Repress Aryl Hydrocarbon Receptor Signaling

The aryl hydrocarbon receptor (AHR) regulates the toxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The AHR repressor (AHRR) is an AHR target gene and functions as a ligand-induced repressor of AHR; however, its mechanism of inhibition is controversial. Recently, we reported that TCDD-inducible poly (ADP-ribose) polymerase (TiPARP; ARTD14) also acts as a repressor of AHR, representing a new player in the mechanism of AHR action. Here we compared the ability of AHRR- and TiPARP-mediated inhibition of AHR activity. TCDD increased AHRR mRNA levels and recruitment of AHRR to cytochrome P450 1A1 (CYP1A1) in MCF7 cells. Knockdown of TiPARP, but not AHRR, increased TCDD-induced CYP1A1 mRNA and AHR protein levels. Similarly, immortalized TiPARP−/− mouse embryonic fibroblasts (MEFs) and AHRR−/− MEFs exhibited enhanced AHR transactivation. However, unlike TiPARP−/− MEFs, AHRR−/− MEFs did not exhibit increased AHR protein levels. Overexpression of TiPARP in AHRR−/− MEFs or AHRRΔ8, the active isoform of AHRR, in TiPARP−/− MEFs reduced TCDD-induced CYP1A1 mRNA levels, suggesting that they independently repress AHR. GFP-AHRRΔ8 and GFP-TiPARP expressed as small diffuse nuclear foci in MCF7 and HuH7 cells. GFP-AHRRΔ8_Δ1-49, which lacks its putative nuclear localization signal, localized to both the nucleus and the cytoplasm, while the GFP-AHRRΔ8_Δ1-100 mutant localized predominantly in large cytoplasmic foci. Neither GFP-AHRRΔ8_Δ1-49 nor GFP-AHRRΔ8_Δ1-100 repressed AHR. Taken together, AHRR and TiPARP repress AHR transactivation by similar, but also different mechanisms.
Reconfigurations in Graphs and Grids

Let G be a connected graph, and let V and V ′ two n-element subsets of its vertex set V(G). Imagine that we place a chip at each element of V and we want to move them into the positions of V ′ (V and V ′ may have common elements). A move is defined as shifting a chip from v1 to v2 (v1,v2 ∈ V(G)) on a path formed by edges of G so that no intermediate vertices are occupied. We give upper and lower bounds on the number of moves that are necessary, and analyze the computational complexity of this problem under various assumptions: labeled versus unlabeled chips, arbitrary graphs versus the case when the graph is the rectangular (infinite) planar grid, etc. We provide hardness and inapproximability results for several variants of the problem. We also give a linear-time algorithm which performs an optimal (minimum) number of moves for the unlabeled version in a tree, and a constant-ratio approximation algorithm for the unlabeled version in a graph. The graph algorithm uses the tree algorithm as a subroutine.
Thermo-mechanical Reliability Study of High I/Os Flip Chip On Laminated Substrate Based on FEA, RSM and Interfacial Fracture Mechanics

This paper described a comprehensive study of thermo-mechanical reliability of high input/outputs (I/Os) flip-chip on laminated substrate by using finite element analysis(FEA), response surface methodology(RSM) and interfacial fracture mechanics. Accelerated thermal cycling(ATC) tests for six specimens with different structures and materials were conducted firstly to determine the fatigue life and failure mechanism of the solder joints. Two-dimensional and Three-dimensional FEA corresponding to ATC tests were then conducted individually to analyze the mechanical behavior of the package under ATC conditions. Global-local FEA approach was used because of the large number of solder bumps and the complicated structure of the package. The simulation results of FEA accorded with the tests results well and a fatigue life model in related with accumulated strain energy density was built to estimate the solder joint fatigue life of the package. The combined effect of structural parameters including pad diameter, pad thickness, solder mask open, solder mask thickness and standoff height on the solder joint fatigue life were analyzed by the integration of two-dimensional FEA and central composite design (CCD) based RSM, and a response surface model was established to make the optimization. Due to imperfect manufacturing process, very small interfacial cracks commonly exist between the interface of solder joint and copper pad after reflow, the interfacial fracture behavior of the crack for different crack lengths under ATC conditions were investigated with two-dimensional FEA. Interfacial fracture mechanics and crack surface displacement extrapolation method were used to analyze the variations of strain energy release rate and phase angle at the crack tip
The Anti-Apoptotic Effect of Respiratory Syncytial Virus on Human Peripheral Blood Neutrophils is Mediated by a Monocyte Derived Soluble Factor

Respiratory Syncytial Virus (RSV) causes annual epidemics of respiratory disease particularly affecting infants. The associated airway inflammation is characterized by an intense neutrophilia. This neutrophilic inflammation appears to be responsible for much of the pathology and symptoms. Previous work from our group had shown that there are factors within the airways of infants with RSV bronchiolitis that inhibit neutrophil apoptosis. This study was undertaken to determine if RSV can directly affect neutrophil survival. Neutrophils were isolated from citrated venous blood (collected from healthy adult volunteers) by discontinuous plasma: Percoll gradient centrifugation and, in some experiments, further purified by negative immunomagnetic bead selection. The effect of RSV on neutrophil survival was measured by Annexin V-PE /To-Pro-3 staining and by morphological changes, using Dif-Quick staining of cytospins. Inhibition of neutrophil apoptosis was observed in neutrophils isolated by standard plasma:Percoll gradient when exposed to RSV but not in ultra pure neutrophil preparations. Adding monocytes back to ultra purified preparations restored the effect. The inhibition of apoptosis was observed with both active and UV inactivated virus. The effect is dependent on a soluble factor and appears to be dependent on CD14 receptors on the monocytes.