Miracle-dz/UniFAR-FTUs huggingface dataset:
Trust-based Sybil nodes detection with robust seed selection and graph pruning on SNS

On SNS (Social Networking Services), detecting Sybils is an urgent demand. The most famous approach is called “SybilRank” scheme where each node evenly distributes its trust value that is firstly given to honest seeds and detects Sybils based on the trust value. Furthermore, Zhang et al. proposed to avoid trust values from being distributed into Sybils by pruning suspicious relationships before SybilRank. However, we point out that the above two schemes have shortcomings that must be remedied. In the former scheme, seeds are concentrated on the specific communities and thus the trust value is not evenly distributed. Against the latter one, a sophisticated attacker can avoid graph pruning by making relationships between Sybil nodes. In this paper, we propose a robust seed selection and graph pruning scheme to detect Sybil nodes. To more evenly distribute trust value into honest nodes, we first detect communities in the SNS and select honest seeds from each detected community. And then, based on the fact that Sybils cannot make dense relationships with honest nodes, we also propose a graph pruning scheme based on the density of relationships between trusted nodes. We prune the relationships which have sparse relationships with trusted nodes and this enables robust pruning malicious relationships even if the attackers make a large number of common friends. By the computer simulation with real dataset, we show that our scheme improves the detection accuracy of both Sybil and honest nodes.
A Versatile Simple Capture Assay for Assessing the Structural Integrity of MHC Multimer Reagents

Antigen-specific T cell responses can be visualized using MHC:peptide multimers. In cases where robust T cell controls are not readily available to assess the integrity of multimer reagents prior to analyzing limited sample, the ability to assess the structural integrity of MHC multimers before their use in critical experiments would be useful. We present a method to probe the structural integrity of MHC multimers using antibodies specific for conformational determinants. Beads coated with anti-mouse Ig are incubated with conformation-specific mouse monoclonal antibody and then with fluorescently tagged MHC multimer. The ability of the bead to capture the labeled multimer can be measured semi-quantitatively by flow cytometry. In this manner, the correct folding of MHC multimers can be visualized and batches of multimer can be compared for quality control. Because there are multiple conformational epitopes formed by various molecular interactions among heavy chain, peptide, and β2M, this capture assay can assess the fidelity of each aspect of multimer structure, depending on the availability of antibodies. The described approach could be particularly useful for studies using irreplaceable samples, including patient samples collected in clinical trials.
Feeding Supplemental Dried Distiller’s Grains Increases Faecal Shedding of Escherichia coli O157 in Experimentally Inoculated Calves

Escherichia coli O157 is an important foodborne pathogen and asymptomatic cattle serve as major reservoirs for human infection. We have shown a positive association between feeding distiller’s grains and E. coli O157 prevalence in feedlot cattle. The objective of this study was to determine the effect of feeding dried distiller’s grain (DDG) on faecal shedding of E. coli O157 in calves experimentally inoculated with E. coli O157. Holstein calves (five per treatment group), fed steam‐flaked corn‐based high‐grain diets supplemented with 0% (control) or 25% DDG, were orally inoculated with a five‐strain mixture (6 × 109 CFU/calf) of nalidixic acid‐resistant (NalR) E. coli O157. Faecal samples were taken three times per week for 6 weeks to determine the prevalence and concentration of NalRE. coli O157. At the end of the study (day 43), calves were euthanized and necropsied. Ruminal, caecum, colon, and rectal contents, and rectoanal mucosal swab (RAMS) samples were collected at necropsy to determine NalRE. coli O157 concentration. There was a trend for an interaction between treatment and faecal sampling day. The concentration of NalRE. coli O157 in the faeces was significantly higher in faecal samples from calves fed DDG compared with control calves on days 35, 37, 39 and 42. At necropsy, the concentration of NalRE. coli O157 was higher in the caecum (P = 0.01), colon (P = 0.03) and rectum (P = 0.01) from calves fed DDG compared with control animals. The number of sites at necropsy positive for NalRE. coli O157 was higher in calves fed DDG compared with calves in the control treatment (P < 0.001). Our results indicate that E. coli O157 gut persistence and faecal prevalence increased in calves fed DDG, which potentially have important implications for food safety.
Statistical methods for evidence synthesis

In many empirical disciplines, scientific discovery is modularized into discrete papers each investigating one or more hypotheses. Synthesizing these modules of evidence is critical to inform a balanced and appropriately evolving view of the overall evidence on a topic as well as to identify where substantial uncertainty remains. This dissertation considers three realms in which such synthesis can occur: (1) when meta-analyzing multiple studies; (2) when subjecting a single study to independent replications; and (3) when testing related hypotheses within a study. We consider specific methodological challenges within each of these realms and propose statistical methods to address each. All proposed methods are implemented in R packages.
Structure and ultrastructure of the labial salivary glands in patients with cystic fibrosis

The morphology of the labial salivary glands in subjects with and without cystic fibrosis has been studied by light and electron microscopy. The terms `light' cell, `dark' cell, `clear' cell, and `myoepithelial' cell are used to describe the four cell types distinguished at the level of the electron microscope. The dark cells were found to stain specifically with alcian blue at and above pH 1·0, and the light cells to stain specifically using the periodic acid-Schiff (PAS) technique. This staining reaction suggests that an acidic mucosubstance is being produced by the dark cells and a neutral mucosubstance by the light cells. While no marked morphological differences were observed in the labial glands of patients with cystic fibrosis when contrasted with normal controls, it was observed that the cells from patients with cystic fibrosis contained quantitatively more mucus.
Cardiovascular responses to nasal water flow in rats are unaffected by chemoreceptor drive.

Peripheral chemoreceptors generally play a limited role in the initial development of diving bradycardia in mammals. However, T.F. Huang and Y.I. Peng (Jpn. J. Physiol. 26: 395-401, 1976) reported that peripheral chemoreceptors are very important for manifestation of the diving response in conscious rats. The objectives of this study were to reinvestigate those findings and determine whether the cardiovascular responses to simulated diving in the rat were potentiated during preexisting hypoxia or hypercapnia. Responses to simulated diving were elicited by nasal water flow with concurrent apnea in paralyzed, artificially ventilated Sprague-Dawley rats anesthetized with Innovar. The experiments show that nasal stimulation in the rat results in rapid bradycardia and hypotension and that these responses are not due to laryngeal stimulation. The data also suggest that chemoreceptors do not play a role in the initiation of the responses to simulated diving in rats and that preexisting chemoreceptor drive does not alter the cardiovascular responses. Additionally, we found that concomitant expiratory apnea is necessary to sustain the profound initial cardiovascular changes induced by nasal water flow.
PADS: A Policy Architecture for Distributed Storage Systems

This paper presents PADS, a policy architecture for building distributed storage systems. A policy architecture has two aspects. First, a common set of mechanisms that allow new systems to be implemented simply by defining new policies. Second, a structure for how policies, themselves, should be specified. In the case of distributed storage systems, PADS defines a data plane that provides a fixed set of mechanisms for storing and transmitting data and maintaining consistency information. PADS requires a designer to define a control plane policy that specifies the system-specific policy for orchestrating flows of data among nodes. PADS then divides control plane policy into two parts: routing policy and blocking policy. The PADS prototype defines a concise interface between the data and control planes, it provides a declarative language for specifying routing policy, and it defines a simple interface for specifying blocking policy. We find that PADS greatly reduces the effort to design, implement, and modify distributed storage systems. In particular, by using PADS we were able to quickly construct a dozen significant distributed storage systems spanning a large portion of the design space using just a few dozen policy rules to define each system.
Barriers to Effective Formulation of Code of Ethics in a Medical University

Background: Every year many organizations formulate a Code of Ethics (COE) but when it comes to implementing, it does not achieve the desired purposes. Ineffectiveness of COEs can stem from different factors and surely, one of them is bad formulation. This research was conducted to identify the barriers to effective formulation of COEs in one of the main state universities of medical sciences in Iran. Methods: A qualitative approach using thematic analysis in three stages of descriptive coding, interpretative coding and overarching themes was adopted to analyze data collected through 27 semi-structured interviews. This study was conducted in 2014–15 at Shahid Beheshti University of Medical Sciences, Tehran, Iran. Results: Totally 135 descriptive themes, 12 interpretive themes and 3 overarching themes emerged through analyzing interviews. Conclusion: In order to have an implementable COE, 12 barriers in three categories including “goal-setting”, “approach” and “content” of the COE, must be removed. In “goal-setting”, real cultural conditions of the medical university must be considered. Moreover, the COE must be in response to perceived internal needs and its philosophy must be clear for all members of the university. Besides, the formulation “approach” of the COEs must be specialist, participatory and expertised. Finally, in “content”, different stakeholders with diverse values, levels of knowledge and needs should be carefully addressed. In addition, it is proposed to emphasize religious and humane values to encourage participation of people. As a final point, the university should avoid imitation in the content of the COE, and conceptualize the values in motivating, inspirational and guiding words.
Transmission of HIV-1 Gag immune escape mutations is associated with reduced viral load in linked recipients

In a study of 114 epidemiologically linked Zambian transmission pairs, we evaluated the impact of human leukocyte antigen class I (HLA-I)–associated amino acid polymorphisms, presumed to reflect cytotoxic T lymphocyte (CTL) escape in Gag and Nef of the virus transmitted from the chronically infected donor, on the plasma viral load (VL) in matched recipients 6 mo after infection. CTL escape mutations in Gag and Nef were seen in the donors, which were subsequently transmitted to recipients, largely unchanged soon after infection. We observed a significant correlation between the number of Gag escape mutations targeted by specific HLA-B allele–restricted CTLs and reduced VLs in the recipients. This negative correlation was most evident in newly infected individuals, whose HLA alleles were unable to effectively target Gag and select for CTL escape mutations in this gene. Nef mutations in the donor had no impact on VL in the recipient. Thus, broad Gag-specific CTL responses capable of driving virus escape in the donor may be of clinical benefit to both the donor and recipient. In addition to their direct implications for HIV-1 vaccine design, these data suggest that CTL-induced viral polymorphisms and their associated in vivo viral fitness costs could have a significant impact on HIV-1 pathogenesis.
Sequence-dependent DNA structure: the role of the sugar-phosphate backbone.

A detailed analysis of the coupling between the conformational properties of the sugar-phosphate backbone and the base stacking interactions in dinucleotide steps of double helical DNA is described. In X-ray crystal structures of oligonucleotides, the backbone shows one major degree of freedom, consisting of the torsion angles chi, delta, zeta and the pseudorotation phase angle, P. The remaining torsion angles (beta, epsilon, alpha and gamma) comprise two less important degrees of freedom. The base stacking interactions show three degrees of freedom: slide-roll-twist, shift-tilt, and rise (which is more or less constant). Coupling is observed between the base and backbone degrees of freedom. The major base stacking mode, slide-roll-twist, is coupled to the major backbone mode, chi-P-delta-zeta. The secondary base stacking mode, shift-tilt, is coupled to epsilon and zeta and to a lesser extent to the chi-P-delta-zeta mode. We show that the length of the backbone, C, given by the same strand C1'-C1' separation, is an excellent single parameter descriptor for the conformation of the backbone and the way in which it is coupled to the base stacking geometry. The slide-roll-twist motion relates to changes in the mean backbone length, C, and the shift-tilt motion to the difference between the lengths of the two backbone strands, DeltaC. We use this observation to develop a simple virtual bond model which describes the coupling of the backbone conformations and the base stacking geometry. A semi-flexible bond is used to connect the same strand C1'-C1' atoms. Analysis of the X-ray crystal structure database, simple geometric considerations and model building experiments all show that this bond is flexible with respect to slide, shift and propeller but rigid with respect to the other 14 local base stacking parameters. Using this simple model for the backbone in conjunction with potential energy calculations of the base stacking interactions, we show that it is possible to predict accurately the values of these 14 base step parameters, given values of slide, shift and propeller. We also show that the base step parameters fall into three distinct groups: roll, tilt and rise are determined solely by the base stacking interactions and are independent of the backbone; twist is insensitive to the base stacking interactions and is determined solely by the constraints of a relatively rigid fixed length backbone; slide and shift are the primary degrees of freedom and cannot be predicted accurately at the dinucleotide level because they are influenced by the conformations of neighbouring steps in a sequence. We have found that the context effect on slide is mediated by the chi torsion angles while the context effect on shift results from a BI to BII transition in the backbone. We have therefore reduced the dimensionality of the dinucleotide step problem to two parameters, slide and shift.
Antimycobacterial Activities of Novel 5-(1H-1,2,3-Triazolyl)Methyl Oxazolidinones

The antibacterial activities of a series of triazolyl oxazolidinones against Mycobacterium tuberculosis strain in vitro and in vivo in a mice model are presented. Most active compounds were noncytotoxic against VERO cells with acceptable selectivity indexes (SI) as measures of compound tolerability. Structure activity relationships (SARs) revealed that analogs with alkylcarbonyl (IC90: < 0.2 to 0.422 μg/mL) and arylcarbonyl (IC90: < 0.2 to 2.103 μg/mL) groups at the piperazine 4N-position-displayed potent antimycobacterium activities, comparable to the methanesulfonyl (IC90: < 0.2 μg/mL) analog, linezolid (IC90: < 0.2 μg/mL), and isoniazid (IC90: < 0.034 μg/mL). The furanylcarbonyl derivative also displayed potent activity, while the arylsulfonyl analogs were inactive. Of the triazolyl oxazolidinones, the morpholino (PH-27) derivative with medium bioavailability in plasma was most active in vivo, but relatively less efficacious than isoniazid.
Latent Feature Based Recommender System for Learning Materials Using Genetic Algorithm

With the explosion of learning materials available on personal learning environments (PLEs) in the recent years, it is difficult for learners to discover the most appropriate materials according to keyword searching method. Recommender systems (RSs) that are used to support activity of learners in PLE can deliver suitable material to learners. This technology suffers from the cold-start and sparsity problems. On the other hand, in most researches, less attention has been paid to latent features of products. For improving the quality of recommendations and alleviating sparsity problem, this research proposes a latent feature based recommendation approach. Since usually there isn’t adequate information about the observed features of learner and material, latent features are introduced for addressing sparsity problem. First preference matrix (PM) is used to model the interests of learner based on latent features of learning materials in a multidimensional information model. Then, we use genetic algorithm (GA) as a supervised learning task whose fitness function is the mean absolute error (MAE) of the RS. GA optimizes latent features weight for each learner based on his/her historical rating. The method outperforms the previous algorithms on accuracy measures and can alleviate the sparsity problem. The main contributions are optimization of latent features weight using genetic algorithm and alleviating the sparsity problem to improve the quality of recommendation.
Tumor immunotherapy in the mouse with the use of 131I-labeled monoclonal antibodies.

This report describes the use of 131I-labeled monoclonal antibodies in two experimental models for tumor immunotherapy. In vitro treatment of the radiation-induced murine thymoma ITT-1-75NS with radiolabeled anti-Ly-2.1 significantly impaired subsequent tumor growth in vivo. However, in vivo treatment of this tumor, which previously had been injected into C57BL/6 mice, was unsuccessful. By contrast, in vitro treatment of a human colorectal tumor cell line (COLO 205) with 131I-labeled 250-30.6--a monoclonal antibody directed against a secretory component of normal and malignant gastrointestinal epithelium--completely inhibited subsequent tumor growth in BALB/c nude (nu/nu) mice. Furthermore, in vivo treatment of preexisting human colorectal tumor xenografts significantly impaired progressive tumor growth. Although some tumor inhibition was also produced by unlabeled 250-30.6 antibody, this response was considerably amplified by treatment with [131I]-labeled 250-30.6 (P less than .05), suggesting that in vivo treatment of human tumors with the use of 131I-labeled monoclonal antibodies may be clinically beneficial. The antithyroid drug propylthiouracil was used to reduce dehalogenation of the radiolabeled immunoglobulins in an attempt to improve their therapeutic efficacy.
Subtitle positioning for e-learning videos based on rough gaze estimation and saliency detection

Subtitle is very common shown in a variety categories of videos, especially useful as translated subtitles for native speakers. Traditional subtitle is placed at the bottom of videos in order to prevent from occluding essential video contents. However, traversing between important video contents and subtitle frequently will have a negative impact on focusing watching video itself. Recently, some research work try more flexible subtitle positioning strategy. However, these methods are effective with restrictions on the video content and devices adopted. In this work, we propose a novel subtitle content organization and placement framework based on rough gaze estimation and saliency detection.
Strong thresholds for ℓ2/ℓ1-optimization in block-sparse compressed sensing

It has been known for a while that l1-norm relaxation can in certain cases solve an under-determined system of linear equations. Recently, [5, 10] proved (in a large dimensional and statistical context) that if the number of equations (measurements in the compressed sensing terminology) in the system is proportional to the length of the unknown vector then there is a sparsity (number of non-zero elements of the unknown vector) also proportional to the length of the unknown vector such that l1-norm relaxation succeeds in solving the system. In this paper we determine sharp lower bounds on the values of allowable sparsity for any given number (proportional to the length of the unknown vector) of equations for the case of the so-called block-sparse unknown vectors considered in [25].
Detection and Quantification of Botulinum Neurotoxin Type A by a Novel Rapid In Vitro Fluorimetric Assay

ABSTRACT Botulinum neurotoxin type A (BoNT/A), the most poisonous substance known to humans, is a potential bioterrorism agent. The light-chain protein induces a flaccid paralysis through cleavage of the 25-kDa synaptosome-associated protein (SNAP-25), involved in acetylcholine release at the neuromuscular junction. BoNT/A is widely used as a therapeutic agent and to reduce wrinkles. The toxin is used at very low doses, which have to be accurately quantified. With this aim, internally quenched fluorescent substrates containing the fluorophore/repressor pair pyrenylalanine (Pya)/4-nitrophenylalanine (Nop) were developed. Nop and Pya were, respectively, introduced at positions 197 and 200 of the cleavable fragment (amino acids 187 to 203) of SNAP-25 (with norleucine at position 202 [Nle202]), which is acetylated at its N terminus and amidated at its C terminus. Cleavage of this peptide occurred between positions 197 and 198, as in SNAP-25, and was easily quantified by the strong fluorescence emission of the metabolite. To increase the assay sensitivity, the peptide sequence of the previous substrate was lengthened to account for exosite binding to BoNT/A. We synthesized the peptide PL50 (SNAP-25-NH2 acetylated at positions 156 to 203 [Nop197, Pya200, Nle202]) and its analogue PL51, in which all methionines were replaced by nonoxidizable Nle. Consistent with a large increase in affinity for BoNT/A, PL50 and PL51 exhibit catalytic efficiencies of 2.6 × 106 M−1 s−1 and 8.85 × 106 M−1 s−1, respectively, and behave as the best fluorigenic substrates of BoNT/A reported to date. Under optimized assay conditions, they allow simple quantification of as little as 100 and 60 pg of BoNT/A, respectively, within 2 h with a classical fluorimeter. Calibration of the method against the mouse 50% lethal dose assay unequivocally validates the enzymatic assay.
Double talk cancellation in echo cancelled DMT-systems

The existing ADSL standard allows for two possible transmission systems: frequency division duplexing (FDD) and echo cancelling (EC). Echo cancelling is particularly attractive for its ability to achieve higher data rates compared with FDD schemes. A disadvantage of EC is that adaptive schemes exhibit slow tracking properties in the presence of a far end signal or double talker. This paper presents an efficient method for updating echo canceller taps in ADSL transceivers in the presence of a far end signal, by effectively cancelling most of the received far end energy. The presented scheme extends existing multicarrier echo cancelling schemes with a feedback of decisions on the far end signal. As a result the convergence is much faster and hence fast tracking properties are possible at a low computational complexity.