Miracle-dz/UniFAR-FTUs huggingface dataset:
Tight Approximation Algorithms for Bichromatic Graph Diameter and Related Problems

Some of the most fundamental and well-studied graph parameters are the Diameter (the largest shortest paths distance) and Radius (the smallest distance for which a "center" node can reach all other nodes). The natural and important $ST$-variant considers two subsets $S$ and $T$ of the vertex set and lets the $ST$-diameter be the maximum distance between a node in $S$ and a node in $T$, and the $ST$-radius be the minimum distance for a node of $S$ to reach all nodes of $T$. The bichromatic variant is the special case in which $S$ and $T$ partition the vertex set. In this paper we present a comprehensive study of the approximability of $ST$ and Bichromatic Diameter, Radius, and Eccentricities, and variants, in graphs with and without directions and weights. We give the first nontrivial approximation algorithms for most of these problems, including time/accuracy trade-off upper and lower bounds. We show that nearly all of our obtained bounds are tight under the Strong Exponential Time Hypothesis (SETH), or the related Hitting Set Hypothesis. For instance, for Bichromatic Diameter in undirected weighted graphs with $m$ edges, we present an $\tilde{O}(m^{3/2})$ time $5/3$-approximation algorithm, and show that under SETH, neither the running time, nor the approximation factor can be significantly improved while keeping the other unchanged.
An Inner Disk in the Large Gap of the Transition Disk SR 24S

We report new Atacama Large Millimeter/submillimeter Array (ALMA) Band 3 observations at 2.75 mm of the transition disk around SR 24S, with an angular resolution of ∼0. ″11 × 0. ″09 and a peak signal-to-noise ratio of ∼24. We detect an inner disk and a mostly symmetric ring-like structure that peaks at ∼0. ″32, which is ∼37 au at a distance of ∼114.4 pc. The full width at half maximum of this ring is ∼28 au. We analyze the observed structures by fitting the dust continuum visibilities using different models for the intensity profile, and compare with previous ALMA observations of the same disk at 0.45 and 1.30 mm. We qualitatively compare the results of these fits with theoretical predictions of different scenarios for the formation of a cavity or large gap. The comparison of the dust continuum structure between different ALMA bands indicates that photoevaporation and the dead zone can be excluded as leading mechanisms for the cavity formation in the SR 24S disk, leaving the planet scenario (single or multiple planets) as the most plausible mechanism. We compared the 2.75 mm emission with published (sub)centimeter data and find that the inner disk is likely tracing dust thermal emission. This implies that any companion in the system should allow dust to move inwards throughout the gap and replenish the inner disk. In the case of one single planet, this puts strong constraints on the mass of the potential planet inside the cavity and the disk viscosity of about ≲5 MJup and α ∼ 10−4–10−3, respectively.
Sensing Matrix Design and Sparse Recovery on the Sphere and the Rotation Group

In this article, the goal is to design deterministic sampling patterns on the sphere and the rotation group and, thereby, construct sensing matrices for sparse recovery of band-limited functions. It is first shown that random sensing matrices, which consists of random samples of Wigner D-functions, satisfy the Restricted Isometry Property (RIP) with proper preconditioning and can be used for sparse recovery on the rotation group. The mutual coherence, however, is used to assess the performance of deterministic and regular sensing matrices. We show that many of widely used regular sampling patterns yield sensing matrices with the worst possible mutual coherence, and therefore are undesirable for sparse recovery. Using tools from angular momentum analysis in quantum mechanics, we provide a new expression for the mutual coherence, which encourages the use of regular elevation samples. We construct low coherence deterministic matrices by fixing the regular samples on the elevation and minimizing the mutual coherence over the azimuth-polarization choice. It is shown that once the elevation sampling is fixed, the mutual coherence has a lower bound that depends only on the elevation samples. This lower bound, however, can be achieved for spherical harmonics, which leads to new sensing matrices with better coherence than other representative regular sampling patterns. This is reflected as well in our numerical experiments where our proposed sampling patterns perfectly match the phase transition of random sampling patterns.
A NASDAQ Market Simulation - Insights on a Major Market from the Science of Complex Adaptive Systems

This pioneering book describes the applications of agent-based modeling to financial markets. It presents a new paradigm for finance, where markets are treated as complex systems whose behavior emerges as a result of interactions of market participants, market institutions, and market rules. This includes both a presentation of the conceptual model and its software implementation. It also summarises the result of the profound research on the successful practical application of this new approach to answer questions regarding the Nasdaq Stock Market s decimalization that was implemented in 2001. The book presents conceptual foundations for modeling markets as complex systems. It describes the agent-based model of the Nasdaq stock market, including strategies used by market-makers and investors, market participants interactions, and impacts of rules and regulations. It includes analyses of simulation behavior, comparison with the behaviors observed in the real-world markets (existence of fat tails, spread clustering, etc.), and predictions about possible outcomes of decimalization. A framework for calibrating the market behavior and individual market-makers strategies to historical data is also presented.
Detecting occluded people for robotic guidance

Often overlooked in human-robot interaction is the challenge of people detection. For natural interaction, a robot must detect people without waiting for them to face the camera, get far enough away to be fully present, or center themselves fully within the field of view. Furthermore, it must happen without requiring immense amounts of processing that are not practical for real systems. In this work we focus on person detection in a guidance scenario, where occlusion is particularly prevalent. Using a layered approach with depth images, we can substantially improve detection rates under high levels of occlusion, and enable a robot to detect a target that is moving into and out of the field of view.
The effect of location error on microseismic mechanism estimation : synthetic and real field data examples

T he decomposing of the full moment tensor of microseismic events observed during hydraulic fracture stimulations into double couple (%DC), compensated linear vector dipole (%CLVD), and isotropic (%ISO) components has been shown to be useful for making more complete characterizations of these events (Williams-Stroud, 2008). While this information about the nature and geometry of a fracture is important and very telling, any source of potential error in these decompositions must be taken into account. One source of particular importance to microseismic monitoring is the effect of location error on the full moment decomposition. With this type of analysis becoming more prevalent, there is concern as to whether the effect of location error on potential interpretations and recommendations based on microseismic fracture geometry is thoroughly understood. Moment tensor inversion of microseismic data is an immensely powerful interpretation tool. An understanding of the nature of the rock failure supports the development of discrete fracture networks (DFN), reservoir simulation models, and stimulated reservoir volume estimates. Such interpretations are a large part of the driving force behind the growth in microseismic monitoring. Furthermore, a proper characterization of the event mechanism is necessary in full waveform imaging of microseismic data to properly account for the radiation pattern of the signals (Duncan, 2010). While determination of event strike, dip and rake can provide the geometry of the fracture plane, full moment inversion and decomposition provides insight into the shear versus tensile nature of the fracture planes. Historically, this has been presented through source component plots (Hudson, 1989) and tensile parameter analysis, which is commonly displayed in global earthquake seismology (Vavryčuk, 2001). However, interpretations are often made without considering possible sources of error in the decomposition itself. Given the non-unique nature of the deviatoric component of the moment tensor, it is important to include possible sources of noise in the moment tensor to ensure a reliable solution. The idea of errors and noise being introduced into moment tensor decomposition has been assessed in detail in earthquake seismology (Vavryčuk, 2001; Vavryčuk, 2002), but remains mostly dismissed in microseismic analysis. While many sources of error are cited in such seismology studies, this paper will focus on event location error as this is a primary calibration concern for all basins and imaging techniques.
Fatigue Perceived by Multiple Sclerosis Patients Is Associated With Muscle Fatigue

Background. Fatigue is a debilitating symptom in multiple sclerosis (MS). Previous studies showed no association between fatigue as perceived by the patient and physiological measures of fatigability. Objective. The authors investigated associations between perceived fatigue and measures of fatigability after correction for differences in maximal voluntary contraction (MVC). Methods. A total of 20 people with relapsing-remitting MS with an Extended Disability Severity Score less than 5.5 and 20 healthy controls filled out the Fatigue Severity Score questionnaire of perceived fatigue. The authors obtained the MVC from the first dorsal interosseus muscle, voluntary muscle activation, and force decline during a sustained MVC (124 s, muscle fatigue). Results. Patients perceived increased levels of fatigue compared with controls (P < .001). Although patients and controls developed similar amounts of muscle fatigue during the sustained contraction, a linear regression model that included both muscle fatigue and MVC was positively associated with perceived fatigue in patients only (R2 = 0.45; P = .01). Voluntary activation during the sustained contraction was negatively associated with perceived fatigue (R2 = 0.25; P = .02). Conclusion. The data indicate that fatigue perceived by MS patients is associated with measures of fatigability. This observation helps in the understanding of mechanisms underlying the increased levels of fatigue perceived by MS patients. These data also emphasize that for comparison of fatigue-related parameters between groups, correction for individual maximal force is essential.
Biopathways representation and simulation on hybrid functional Petri net

The following two matters should be resolved in order for biosimulation tools to be accepted by users in biology/medicine: (1) remove issues which are irrelevant to biological importance, and (2) allow users to represent biopathways intuitively and understand/manage easily the details of representation and simulation mechanism. From these criteria, we firstly define a novel notion of Petri net called Hybrid Functional Petri Net (HFPN). Then, we introduce a software tool, Genomic Object Net, for representing and simulating biopathways, which we have developed by employing the architecture of HFPN. In order to show the usefulness of Genomic Object Net for representing and simulating biopathways, we show two HFPN representations of gene regulation mechanisms of Drosophila melanogaster (fruit fly) circadian rhythm and apoptosis induced by Fas ligand. The simulation results of these biopathways are also correlated with biological observations. The software is available to academic users from http://www.GenomicObject. Net/.
Genetic Diversity and Phylogeny of Antagonistic Bacteria against Phytophthora nicotianae Isolated from Tobacco Rhizosphere

The genetic diversity of antagonistic bacteria from the tobacco rhizosphere was examined by BOXAIR-PCR, 16S-RFLP, 16S rRNA sequence homology and phylogenetic analysis methods. These studies revealed that 4.01% of the 6652 tested had some inhibitory activity against Phytophthora nicotianae. BOXAIR-PCR analysis revealed 35 distinct amplimers aligning at a 91% similarity level, reflecting a high degree of genotypic diversity among the antagonistic bacteria. A total of 25 16S-RFLP patterns were identified representing over 33 species from 17 different genera. Our results also found a significant amount of bacterial diversity among the antagonistic bacteria compared to other published reports. For the first time; Delftia tsuruhatensis, Stenotrophomonas maltophilia, Advenella incenata, Bacillus altitudinis, Kocuria palustris, Bacillus licheniformis, Agrobacterium tumefaciens and Myroides odoratimimus are reported to display antagonistic activity towards Phytophthora nicotianae. Furthermore, the majority (75%) of the isolates assayed for antagonistic activity were Gram-positives compared to only 25% that were Gram-negative bacteria.
Emerging Roles of L-Type Voltage-Gated and Other Calcium Channels in T Lymphocytes

In T lymphocytes, calcium ion controls a variety of biological processes including development, survival, proliferation, and effector functions. These distinct and specific roles are regulated by different calcium signals, which are generated by various plasma membrane calcium channels. The repertoire of calcium-conducting proteins in T lymphocytes includes store-operated CRAC channels, transient receptor potential channels, P2X channels, and L-type voltage-gated calcium (Cav1) channels. In this paper, we will focus mainly on the role of the Cav1 channels found expressed by T lymphocytes, where these channels appear to operate in a T cell receptor stimulation-dependent and voltage sensor independent manner. We will review their expression profile at various differentiation stages of CD4 and CD8 T lymphocytes. Then, we will present crucial genetic evidence in favor of a role of these Cav1 channels and related regulatory proteins in both CD4 and CD8 T cell functions such as proliferation, survival, cytokine production, and cytolysis. Finally, we will provide evidence and speculate on how these voltage-gated channels might function in the T lymphocyte, a non-excitable cell.
Polymeric Nanoparticles in Gene Therapy: New Avenues of Design and Optimization for Delivery Applications

The field of polymeric nanoparticles is quickly expanding and playing a pivotal role in a wide spectrum of areas ranging from electronics, photonics, conducting materials, and sensors to medicine, pollution control, and environmental technology. Among the applications of polymers in medicine, gene therapy has emerged as one of the most advanced, with the capability to tackle disorders from the modern era. However, there are several barriers associated with the delivery of genes in the living system that need to be mitigated by polymer engineering. One of the most crucial challenges is the effectiveness of the delivery vehicle or vector. In last few decades, non-viral delivery systems have gained attention because of their low toxicity, potential for targeted delivery, long-term stability, lack of immunogenicity, and relatively low production cost. In 1987, Felgner et al. used the cationic lipid based non-viral gene delivery system for the very first time. This breakthrough opened the opportunity for other non-viral vectors, such as polymers. Cationic polymers have emerged as promising candidates for non-viral gene delivery systems because of their facile synthesis and flexible properties. These polymers can be conjugated with genetic material via electrostatic attraction at physiological pH, thereby facilitating gene delivery. Many factors influence the gene transfection efficiency of cationic polymers, including their structure, molecular weight, and surface charge. Outstanding representatives of polymers that have emerged over the last decade to be used in gene therapy are synthetic polymers such as poly(l-lysine), poly(l-ornithine), linear and branched polyethyleneimine, diethylaminoethyl-dextran, poly(amidoamine) dendrimers, and poly(dimethylaminoethyl methacrylate). Natural polymers, such as chitosan, dextran, gelatin, pullulan, and synthetic analogs, with sophisticated features like guanidinylated bio-reducible polymers were also explored. This review outlines the introduction of polymers in medicine, discusses the methods of polymer synthesis, addressing top down and bottom up techniques. Evaluation of functionalization strategies for therapeutic and formulation stability are also highlighted. The overview of the properties, challenges, and functionalization approaches and, finally, the applications of the polymeric delivery systems in gene therapy marks this review as a unique one-stop summary of developments in this field.
Physisorption of nucleobases on graphene: a comparative van der Waals study

The physisorption of the nucleobases adenine (A), cytosine (C), guanine (G), thymine (T), and uracil (U) on graphene is studied using several variants of the density functional theory (DFT): the generalized gradient approximation with the inclusion of van der Waals interaction (vdW) based on the TS approach (Tkatchenko and Scheffer 2009 Phys. Rev. Lett. 102 073005) and our simplified version of this approach (here called sTS), the van der Waals density functional vdW-DF (Dion et al 2004 Phys. Rev. Lett. 92 246401) and vdW-DF2 (Lee et al 2010 Phys. Rev. B 82 081101), and DFT-D2 (Grimme 2006 J. Comput. Chem. 27 1787) and DFT-D3 (Grimme et al 2010 J. Chem. Phys. 132 154104) methods. The binding energies of nucleobases on graphene are found to be in the following order: G > A > T > C > U within TS, sTS, vdW-DF, and DFT-D2, and in the following order: G > A > T ∼ C > U within DFT-D3 and vdW-DF2. The binding separations are found to be different within different methods and in the following order: DFT-D2 < TS < DFT-D3 ∼ vdW-DF2 < vdW-DF. We also comment on the efficiency of combining the DFT-D approach and vdW-DF to study systems with van der Waals interactions.
Are preschool children active enough in Shanghai: an accelerometer-based cross-sectional study

Objective Engaging in physical activity (PA) plays an important role in promoting physical and mental health, but the PA data for Chinese preschool children are lacking. This study aims to objectively assess the PA levels of preschool children in Shanghai, China and to evaluate their PA levels relative to age-specific recommendations. Design, setting and participants A cross-sectional study was conducted among preschool children in Shanghai, city of China. There were a total of 303 preschool children (boys, 174; girls, 129) recruited from eight kindergarten classes in the Yangpu and Baoshan Districts of Shanghai. Main outcome measures Daily PA was assessed using ActiGraph GT3X+ accelerometers for seven consecutive days. Children were required to have data from at least 2 weekdays and 1 weekend day, with a minimum daily wear time of 480 min to be included in the analysis. Results Preschool children in Shanghai accumulated, on average, 70.9 min of moderate-to-vigorous PA (MVPA) and 168.0 min of total PA (TPA) per day (d). Boys engaged in more MVPA and TPA than girls (72.8 min/day vs 68.3 min/day and 171.9 min/day vs 162.9 min/day, respectively). Overall, 72.9% of the participants met the age-specific recommendations of MVPA, while 35.3% met TPA recommendations. Conclusions Findings of this study warn of the insufficiency of PA in Shanghai preschool children, suggesting there is substantial room to improve their PA. Trial registration number ChiCTR-OOC-15007439; Results.
Down-Regulation of MHC Class I Expression in Human Keratinocytes Using Viral Vectors Containing US11 Gene of Human Cytomegalovirus and Cultivation on Bovine Collagen-Elastin Matrix (Matriderm®): Potential Approach for an Immune-Privileged Skin Substitute

Skin transplantation, especially in burn patients, is still challenging because surgeons are faced with limited disposability of autologous donor side material. The in vitro culture of keratinocytes has become an important reconstructive option. However, only non-immunogenic allogenic keratinocytes offer the opportunity to develop a skin graft that can overcome rejection. The purpose of the study was to develop targeted gene modification of keratinocytes in order to reduce immunogenicity for the use as allogenic transplantable skin graft by decreasing the expression of MHC class I. To reduce MHC class I expression, viral vectors containing the US11 gene of human cytomegalovirus were generated and tested on their functionality using Western blotting, indirect immunofluorescence staining, and flow cytometry. Transfected keratinocytes were seeded on commercially available bovine collagen-elastin matrices and further cultured for histological and cell survival assays. Results showed transient down-regulation of MHC class I after 24 h post-transfection, with recovery of MHC class I expression after 48 h. Histological assessments showed long-term cell survival as well as histological patterns comparable to epidermal layers of healthy human skin. The data postulates the potential application of US11 transfected keratinocytes as an approach towards an immune-privileged skin substitute. Nevertheless, further studies and data are needed.
Properties of Zero-Free Spectral Matrices

In factor analysis, which is used for example in econometrics, by definition the number of latent variables has to exceed the number of factor variables. The associated transfer function matrix has more rows than columns, and when the factor variables are independent zero mean white noise sequences and the transfer function matrix is stable, then the output spectrum is singular. While a related paper focusses on the properties of such a nonsquare transfer function matrix, in this paper, we explore a number of properties of the spectral matrix and associated covariance sequence. In particular, a zero free minimum degree spectral factor can be computed with a finite number of rational calculations from the spectrum (in contrast to typical spectral factor calculations), assuming the spectrum fulfills a generic condition. Application of the result to Kalman filtering is indicated, and presentation of the results is also achieved using finite block Toeplitz matrices with entries obtained from the covariance of the latent variable vector.
A novel current control method of a three-leg inverter in the stationary frame for a two-phase AC motor

This paper proposes a novel method to control the current of a three-leg voltage source inverter (VSI) supplying a two-phase induction motor (TPIM) in the stationary frame by modulating the potential of neutral leg middle point with a proposed algorithm and using two closed loops with optimized proportional and resonant (PR) controllers to regulate the current. Two conventional current control strategies for conventional three-leg VSI in the stationary frame are presented. Then the novel control method is introduced. Both computer simulation and experiment results show the effectiveness of the proposed method in achieving better performance in terms of total harmonic distortion (THD), peak overshoot value of output current.