Miracle-dz/UniFAR-FTUs huggingface dataset:
High-Frequency Trading and Market Stability∗

In recent years, technological innovations and changes in financial regulation induced a new set of liquidity providers to arise on financial markets: high-frequency traders (HFTs). HFTs differ most notably from traditional liquidity providers in the fact that they combine speed and information processing. We compare a setting with HFTs to settings with liquidity providers that only have speed technology or only information processing technology available. Speed technology by itself will only be adopted when socially efficient. Information processing technology by itself will only generate mild inefficiencies due to a lemons problem. The combination of the two, however, can lead to the implementation of inefficient speed technology, endogenous entry barriers and rents, or to the amplification of the lemons problem. In the latter case, liquidity evaporates when it is most needed and markets can freeze altogether for periods of time. We also discuss how regulation can prevent such sudden drops of liquidity. JEL Codes: D53, G01, G10, G18
Determination of Molecular Phylogenetics of Vibrio parahaemolyticus Strains by Multilocus Sequence Typing

ABSTRACT Vibrio parahaemolyticus is an important human pathogen whose transmission is associated with the consumption of contaminated seafood. There is a growing public health concern due to the emergence of a pandemic strain causing severe outbreaks worldwide. Many questions remain unanswered regarding the evolution and population structure of V. parahaemolyticus. In this work, we describe a multilocus sequence typing (MLST) scheme for V. parahaemolyticus based on the internal fragment sequences of seven housekeeping genes. This MLST scheme was applied to 100 V. parahaemolyticus strains isolated from geographically diverse clinical (n = 37) and environmental (n = 63) sources. The sequences obtained from this work were deposited and are available in a public database (http://pubmlst.org/vparahaemolyticus ). Sixty-two unique sequence types were identified, and most (50) were represented by a single isolate, suggesting a high level of genetic diversity. Three major clonal complexes were identified by eBURST analysis. Separate clonal complexes were observed for V. parahaemolyticus isolates originating from the Pacific and Gulf coasts of the United States, while a third clonal complex consisted of strains belonging to the pandemic clonal complex with worldwide distribution. The data reported in this study indicate that V. parahaemolyticus is genetically diverse with a semiclonal population structure and an epidemic structure similar to that of Vibrio cholerae. Genetic diversity in V. parahaemolyticus appears to be driven primarily by frequent recombination rather than mutation, with recombination ratios estimated at 2.5:1 and 8.8:1 by allele and site, respectively. Application of this MLST scheme to more V. parahaemolyticus strains and by different laboratories will facilitate production of a global picture of the epidemiology and evolution of this pathogen.
Macroscopic placental changes associated with fetal and maternal events in diabetes mellitus

OBJECTIVES: The current study sought to identify macroscopic placental changes associated with clinical conditions in women with or without diabetes and their newborns. METHODS: The study population consisted of 62 pregnant women clinically diagnosed with diabetes and 62 healthy women (control group). RESULTS: Among the subjects with diabetes, 43 women (69.3%) were diagnosed with gestational diabetes mellitus, 15 had diabetes mellitus I (24.2%), and four had diabetes mellitus II (6.5%). The mean age of the women studied was 28.5±5.71 years, and the mean gestational age of the diabetic women was 38.51 weeks. Of the 62 placentas from diabetic pregnancies, 49 (79%) maternal surfaces and 59 (95.2%) fetal surfaces showed abnormalities, including calcium and fibrin deposits, placental infarction, hematoma, and fibrosis. A statistical association was found between newborn gender and fetal and maternal placental changes (p = 0.002). The mean weight of the newborns studied was 3,287±563 g for women with diabetes mellitus, 3,205±544 g for those with gestational diabetes mellitus, 3,563±696 g for those with diabetes mellitus II, and 3,095±451 g for those with diabetes mellitus I. CONCLUSIONS: Infarction, hematoma, calcification, and fibrin were found on the maternal and fetal placental surfaces in women with diabetes. Women with gestational diabetes and post-term infants had more calcium deposits on the maternal placental surface as compared to those with type I and type II diabetes.
Collaborative 3D localization of robots from relative pose measurements using gradient descent on manifolds

We propose a distributed algorithm for estimating the full 3-D pose (position and orientation) of multiple autonomous vehicles with respect to a common reference frame when GPS is not available. This algorithm does not rely on the use of any maps, or the ability to recognize landmarks in the environment. Instead we assume that noisy measurements of the relative pose between pairs of robots are intermittently available. We utilize the additional information about each robot's pose provided by these measurements to improve over self-localization estimates. The proposed method is based on solving an optimization problem in an underlying product manifold (SO(3)×R3)n(k). A provably correct explicit gradient descent law is provided. Unlike many previous approaches, the proposed algorithm is applicable to the 3-D case. The method is also capable of handling a fully dynamic scenario where the neighbor relationships are time-varying. Simulations show that the errors in the localization estimates obtained using this algorithm are significantly lower then what is achieved when robots estimate their pose without cooperation. Results from experiments with a pair of ground robots with vision-based sensors reinforce these findings.
Empirical research of influence factors to 3G mobile phone's use

This paper investigates the influence factors to 3G mobile phone's use according to Technology Acceptance Model (TAM). Additionally, this paper build hypotheses model, analyze the factors of this behavioral intentions which consumers use 3G mobile phones and discuss the four factors' influence to the 3G mobile phones use of behavioral intentions. The structural equation model (SEM) technique was used to evaluate the causal model; confirmatory factor analysis was performed to examine the reliability and validity of the measurement model by collected data. Finally, the result is discussed and explained in detail.
Context-aware Model Driven Development: Applications to Web Services Platform

Context-aware applications have been developed since the last decade but until today there has not yet been a common definition about what context means. One thing everybody agrees on is that applications must be more adaptable for each user. Context-aware applications aggregate different types of context to be more personalized and to respond more effectively the user needs. Nevertheless inserting personal context information into application code inhibits software development productivity and reuse. We propose in this work the separation of business logic from context properties in different models, as context depends essentially on a particular environment and user situation. We suggest the use of the Model Driven Development (MDD) approach to design context-aware applications. Context information as models can improve reusability and interoperability in contextual applications. We use a context metamodel and suggest a merging model technique to build CPIM (Contextual Platform Independent Model). By traditional transformation techniques a CPSM (Contextual Platform Specific Model) can be built from a CPIM. Web Service is the target platform used on account of its distributed and interoperable characteristics.
Cloning of the murine eosinophil peroxidase gene (mEPO): characterization of a conserved subgroup of mammalian hematopoietic peroxidases

The mouse eosinophil peroxidase (mEPO) gene was cloned by screening a random‐primed bone marrow cDNA library at reduced criteria using a hEPO cDNA. An mEPO cDNA was subsequently used to isolate the mEPO gene from a λ‐genomic library. The mEPO gene displays a high degree of conservation with its human homologue: the transcription units are approximately the same size, conserve the relative size and position of the 12 exons associated with each gene, and at a nucleotide level the mouse and human EPO genes are 86% identical in the protein coding regions and 66% identical in the 3'‐untranslated trailer regions. This strong conservation extends to the encoded proteins which show ~90% amino acid identity. Expression of the mEPO gene is restricted to tissues containing eosinophil progenitor cells (e.g., bone marrow and spleen), a pattern similar to the expression of another murine eosinophil granule protein, major basic protein. J. Leukoc. Biol. 60: 285–294; 1996.
Exosomal Signaling during Hypoxia Mediates Microvascular Endothelial Cell Migration and Vasculogenesis

Vasculogenesis and angiogenesis are critical processes in fetal circulation and placental vasculature development. Placental mesenchymal stem cells (pMSC) are known to release paracrine factors (some of which are contained within exosomes) that promote angiogenesis and cell migration. The aims of this study were: to determine the effects of oxygen tension on the release of exosomes from pMSC; and to establish the effects of pMSC-derived exosomes on the migration and angiogenic tube formation of placental microvascular endothelial cells (hPMEC). pMSC were isolated from placental villi (8–12 weeks of gestation, n = 6) and cultured under an atmosphere of 1%, 3% or 8% O2. Cell-conditioned media were collected and exosomes (exo-pMSC) isolated by differential and buoyant density centrifugation. The dose effect (5–20 µg exosomal protein/ml) of pMSC-derived exosomes on hPMEC migration and tube formation were established using a real-time, live-cell imaging system (Incucyte™). The exosome pellet was resuspended in PBS and protein content was established by mass spectrometry (MS). Protein function and canonical pathways were identified using the PANTHER program and Ingenuity Pathway Analysis, respectively. Exo-pMSC were identified, by electron microscopy, as spherical vesicles, with a typical cup-shape and diameters around of 100 nm and positive for exosome markers: CD63, CD9 and CD81. Under hypoxic conditions (1% and 3% O2) exo-pMSC released increased by 3.3 and 6.7 folds, respectively, when compared to the controls (8% O2; p<0.01). Exo-pMSC increased hPMEC migration by 1.6 fold compared to the control (p<0.05) and increased hPMEC tube formation by 7.2 fold (p<0.05). MS analysis identified 390 different proteins involved in cytoskeleton organization, development, immunomodulatory, and cell-to-cell communication. The data obtained support the hypothesis that pMSC-derived exosomes may contribute to placental vascular adaptation to low oxygen tension under both physiological and pathological conditions.
Annual Review of Fluid Mechanics Rheology of Active Fluids

An active fluid denotes a viscous suspension of particles, cells, or macromolecules able to convert chemical energy into mechanical work by generating stresses on the microscale. By virtue of this internal energy conversion, these systems display unusual macroscopic rheological signatures, including a curious transition to an apparent superfluid-like state where internal activity exactly compensates viscous dissipation. These behaviors are unlike those of classical complex fluids and result from the coupling of particle configurations with both externally applied flows and internally generated fluid disturbances. Focusing on the well-studied example of a suspension of microswimmers, this review summarizes recent experiments, models, and simulations in this area and highlights the critical role played by the rheological response of these active materials in a multitude of phenomena, from the enhanced transport of passive suspended objects to the emergence of spontaneous flows and collective motion.
Measurement of stress wave attenuation in composite laminates

In structural health monitoring (SHM) of composite members, the choice of sensor positions, frequency band and signal interpretations are directly affected by the attenuation levels. Hence, it is important to consider the influence of attenuation for quantitative interpretation of signals in SHM applications. In this paper, attenuation of the two fundamentals Lamb wave modes, namely the symmetric mode S0 and antisymmetric A0 were experimentally measured in Carbon Fiber Reinforced Polymer (CFRP) laminates. The stress waves were launched using piezoelectric wafers bonded to the center of the laminate. Symmetric and antisymmetric modes were excitation through appropriate combination of two piezoelectric wafers bonded on opposite surfaces of the plate at the same location. The out of plane displacements corresponding to both modes were measured using a scanning laser vibrometer (SLV), along different orientations starting from 00 to 900 at 150 increments. Attenuation coefficients were obtained from 100 kHz to 350 kHz for both cross-ply as well as quasi-isotropic laminates. The attenuation coefficients ranged from about 5 nepers/m to 40 nepers/m. The experimental results as obtained by the scanning laser vibrometer compared favorably with results available in the literature. The antisymmetric mode was found to undergo significantly higher attenuation compared to the symmetric mode. The attenuation of the two modes further depends on the direction of propagation and their frequency components. Because of the dependence of the attenuation level on the Lamb wave mode, frequency, and direction of propagation, a wide frequency content signal such as acoustic emission will undergo substantial changes before being detected by sensors. Successful acoustic emission monitoring will have to take such attenuation into account to get reliable results.
Vehicle/arm coordination and multiple mobile manipulator decentralized cooperation

Mobile manipulation capabilities are key to many new applications of robotics in space, underwater construction, and service environments. This article discusses the ongoing effort at Stanford University for the development of multiple mobile manipulation systems and presents the basic models and methodologies for their analysis and control. This work builds on four methodologies we have previously developed for fixed-base manipulation: the operational space formulation for task-oriented robot motion and force control; the dextrous dynamic coordination of macro/mini structures for increased mechanical bandwidth of robot systems; the augmented object model for the manipulation of objects in a robot system with multiple arms; and the virtual linkage model for the characterization and control of internal forces in a multi-arm system. We present the extension of these methodologies to mobile manipulation systems and propose a new decentralized control structure for cooperative tasks. The article also discusses experimental results obtained with two holonomic mobile manipulation platforms we have designed and constructed at Stanford University.
On the Evolution of Services

In an environment of constant change and variation driven by competition and innovation, a software service can rarely remain stable. Being able to manage and control the evolution of services is therefore an important goal for the Service-Oriented paradigm. This work extends existing and widely adopted theories from software engineering, programming languages, service-oriented computing, and other related fields to provide the fundamental ingredients required to guarantee that spurious results and inconsistencies that may occur due to uncontrolled service changes are avoided. The paper provides a unifying theoretical framework for controlling the evolution of services that deals with structural, behavioral, and QoS level-induced service changes in a type-safe manner, ensuring correct versioning transitions so that previous clients can use a versioned service in a consistent manner.
Natural killer (NK) cell response to virus infections in mice with severe combined immunodeficiency. The stimulation of NK cells and the NK cell-dependent control of virus infections occur independently of T and B cell function

The activation, proliferation, and antiviral properties of natural killer (NK) cells were examined in severe combined immunodeficiency (SCID) mice to determine the influence of mature T or B cells on virus- induced NK cell functions and to more conclusively determine the antiviral properties of prototypical CD3- NK cells. NK cells were activated to high levels of cytotoxicity 3 d after infection of mice with lymphocytic choriomeningitis virus (LCMV) or murine cytomegalovirus (MCMV). Analyses of spleen leukocytes from LCMV- infected mice by a variety of techniques indicated that the NK cells proliferated and increased in number during infection. Propidium iodide staining of the DNA of cycling cells revealed that the great majority of proliferating spleen leukocytes 3 d after LCMV infection was of the NK cell phenotype (CD3-, Ig-, Mac-1+, CZ1+, 50% Thy-1+), in contrast to uninfected mice, whose proliferating cells were predominantly of other lineages. Analyses of the NK cell responses over a 2 wk period in control CB17 mice infected with MCMV indicated a sharp rise in serum interferon (IFN) and spleen NK cell activity early (days 3-5) in infection, followed by sharp declines at later stages. In SCID mice the IFN levels continued to rise over a 10-d period, whereas the NK cell response peaked on day 3-5 and gradually tapered. In contrast to the immunocompetent CB17 mice, SCID mice did not clear the MCMV infection and eventually succumbed. SCID mice, again in contrast to immunocompetent CB17 mice, also failed to clear infections with LCMV and Pichinde virus (PV); these mice, infected as adults, did not die but instead developed long-term persistent infections. Depletion of the NK cells in vivo with antiserum to asialo GM1 rendered both SCID and CB17 control mice much more sensitive to MCMV infection, as shown by titers of virus in organs and by survival curves. In contrast, similar depletions of NK cells did not enhance the titers of the NK cell- resistant virus, LCMV. Two variants of PV, one sensitive to NK cells and the other selected for resistance to NK cells by in vivo passage, were also tested in NK cell-depleted SCID mice. The NK-sensitive PV replicated to higher titers in NK cell-depleted SCID mice, whereas the titers of the NK cell-resistant PV were the same, whether or not the mice had NK cells. These experiments support the concept that CD3- prototypical NK cells mediate resistance to NK cell-sensitive viruses via a mechanism independent of antiviral or "natural" antibody. (ABSTRACT TRUNCATED AT 400 WORDS)
Practical Vision-Based Monte Carlo Localization on a Legged Robot

Mobile robot localization, the ability of a robot to determine its global position and orientation, continues to be a major research focus in robotics. In most past cases, such localization has been studied on wheeled robots with range finding sensors such as sonar or lasers. In this paper, we consider the more challenging scenario of a legged robot localizing with a limited field-of-view camera as its primary sensory input. We begin with a baseline implementation adapted from the literature that provides a reasonable level of competence, but that exhibits some weaknesses in real-world tests. We propose a series of practical enhancements designed to improve the robot’s sensory and actuator models that enable our robots to achieve a 50% improvement in localization accuracy over the baseline implementation. We go on to demonstrate how the accuracy improvement is even more dramatic when the robot is subjected to large unmodeled movements. These enhancements are each individually straightforward, but together they provide a roadmap for avoiding potential pitfalls when implementing Monte Carlo Localization on vision-based and/or legged robots.
GRECS: Graph Encryption for Approximate Shortest Distance Queries

We propose graph encryption schemes that efficiently support approximate shortest distance queries on large-scale encrypted graphs. Shortest distance queries are one of the most fundamental graph operations and have a wide range of applications. Using such graph encryption schemes, a client can outsource large-scale privacy-sensitive graphs to an untrusted server without losing the ability to query it. Other applications include encrypted graph databases and controlled disclosure systems. We propose GRECS (stands for GRaph EnCryption for approximate Shortest distance queries) which includes three oracle encryption schemes that are provably secure against any semi-honest server. Our first construction makes use of only symmetric-key operations, resulting in a computationally-efficient construction. Our second scheme makes use of somewhat-homomorphic encryption and is less computationally-efficient but achieves optimal communication complexity (i.e. uses a minimal amount of bandwidth). Finally, our third scheme is both computationally-efficient and achieves optimal communication complexity at the cost of a small amount of additional leakage. We implemented and evaluated the efficiency of our constructions experimentally. The experiments demonstrate that our schemes are efficient and can be applied to graphs that scale up to 1.6 million nodes and 11 million edges.
SoxC Transcription Factors Are Required for Neuronal Differentiation in Adult Hippocampal Neurogenesis

Neural stem cells (NSCs) generate new hippocampal dentate granule neurons throughout adulthood. The genetic programs controlling neuronal differentiation of adult NSCs are only poorly understood. Here we show that, in the adult mouse hippocampus, expression of the SoxC transcription factors Sox4 and Sox11 is initiated around the time of neuronal commitment of adult NSCs and is maintained in immature neurons. Overexpression of Sox4 and Sox11 strongly promotes in vitro neurogenesis from adult NSCs, whereas ablation of Sox4/Sox11 prevents in vitro and in vivo neurogenesis from adult NSCs. Moreover, we demonstrate that SoxC transcription factors target the promoters of genes that are induced on neuronal differentiation of adult NSCs. Finally, we show that reprogramming of astroglia into neurons is dependent on the presence of SoxC factors. These data identify SoxC proteins as essential contributors to the genetic network controlling neuronal differentiation in adult neurogenesis and neuronal reprogramming of somatic cells.
Position paper on Expressing Relational Data as RDF

Spatial data is generally considered to be complex and difficult to integrate into users’ business processes. Therefore we are looking to semantic to improve our customers’ experience in two ways. Firstly, to provide the means to repurpose our data according to customers’ terminology, which will in effect increase our product portfolio. Secondly, the technology can facilitate the integration of our data with customers’ own, in a semantically meaningful way. This will thus increase the take up of our data; expand our markets into areas that traditionally could not afford to or didn’t know how to use our data and reduce errors in data integration due to implicit assumptions as to the meaning of the data. )