Miracle-dz/UniFAR-FTUs huggingface dataset:
Performance evaluation of novel distributed coverage techniques for swarms of flying robots

This paper focuses on the coverage of specific Zones of Interest that can change dynamically over time by using a swarm of flying robots. The mobility of the flying devices is achieved by the design of two distributed and local algorithms. The first algorithm is based on Particle Swarm Optimization (PSO) and Virtual Forces Algorithm (VFA). We modify the classical PSO approach to propose a totally distributed algorithm, which only requires the flying robots to receive local information from the neighbors to update their velocity and trajectory (PSO-S). This new distributed version of the PSO is combined with a distributed version of the Virtual Forces Algorithm. The second algorithm is a distributed implementation of the VFA (VFA-D). To the best of our knowledge, these two approaches are novel in their distributed character, scalability and implementability on resource-constrained devices. We show that the proposed algorithms are reactive, i.e. able to capture in an effective fashion the events happening within the field even if the position of the events changes over time. To show the effectiveness of the proposed techniques, we perform extensive simulations to compare both the PSO-S and the VFA-D schemes with a centralized version of the VFA. Simulations show the good performance in terms of coverage and traveled distance as well as the high reactivity of both PSO-S and VFA-D when the ZoI changes.
SENSITIVITY ANALYSIS OF PREDICTED CONVECTIVE HEAT TRANSFER AT INTERNAL BUILDING SURFACES TO DIFFUSER MODELLING IN CFD

As a cost-effective alternative to experiments, computational fluid dynamics (CFD) can provide new insight in airflow patterns and the related convective heat transfer (CHT). However, together with the governing equations, the description of th e boundary conditions determines for a greater part t he reliability and the accuracy of CFD simulations. In this study the sensitivity of the predicted CHT to diffuser modelling is studied. Numerical simulation s of a modified version of test case E.2 of the IEA Annex 20-project are performed. The results show a strong influence of the applied diffuser model on t he predicted CHT.
The β Sliding Clamp Closes around DNA prior to Release by the Escherichia coli Clamp Loader γ Complex*

Background: The γ complex loads the ring-shaped β sliding clamp onto DNA. Results: The rate of β clamp closing is faster than the rate of β release on DNA, and the first turnover of ATP hydrolysis is faster than β closing. Conclusion: Clamp closing occurs before clamp release but after a burst of ATP hydrolysis. Significance: These results demonstrate that clamp release around DNA is a two-step process. Escherichia coli γ complex clamp loader functions to load the β sliding clamp onto sites of DNA replication and repair. The clamp loader uses the energy of ATP binding and hydrolysis to drive conformational changes allowing for β binding and opening, DNA binding, and then release of the β·DNA complex. Although much work has been done studying the sliding clamp and clamp loader mechanism, kinetic analysis of the events following β·γ complex·DNA formation is not complete. Using fluorescent clamp closing and release assays, we show that β closing is faster than β release, indicating that γ complex closes β before releasing it around DNA. Using a fluorescent ATP hydrolysis assay, we show that there is a burst of ATP hydrolysis before β closing and that β release may be the rate-limiting step in the overall clamp loading reaction. The combined use of these fluorescent assays provides a unique perspective into the E. coli clamp loader by providing a measure of the relative timing of different events in the clamp loading reaction, helping to elucidate the complicated clamp loading mechanism.
Disks with Jet, ADAF, or EDAF for Sgr A*

We investigate various models of accretion disks for Sgr A*, one of the most puzzling sources in the Galaxy. The generic image we have taken into account consists of a black hole, an accretion disk, and a jet. Various accretion models are able to explain the low NIR flux of Sgr A*: a standard accretion disk with a jet, an ADAF, or an EDAF (Ejection Dominated Accretion Flow) model. We find that all of these models are conceptually similar. The accretion model which allows the formation of the jet at the innermost edge of the disk requires a sub-keplerian gas motion and a very large base of the jet. The large base of the jet may be unrealistic for Sgr A*, since the jet model and the observations suggest that the jet is collimated and anchored in the disk in a very narrow region of the disk close to the black hole. Alternatively, one can think of a jet plus wind model (EDAF), where most of the energy goes out without being dissipated in the disk. The model resembles the ADAF model at small radii. At large radii the energy is ejected by a wind.
The Sum of Its Parts: The Lawyer-Client Relationship in Initial Public Offerings

A question often posed of the legal profession is what (if any) value lawyers add to the endeavors of their clients. However, this framing of the question ignores the fact that lawyers do not add value in a vacuum, but only through effective collaboration with their clients. This Article therefore addresses the question of lawyers' value by examining the working relationship between a lawyer and his or her client. As a lens I analyze one of the most important types of capital markets deals in a company’s existence: its initial public offering (IPO) of company stock. Drawing on data from interviews with equity capital markets lawyers at major law firms, and analyzing data from IPOs in the United States registered with the Securities and Exchange Commission between June 1996 and December 2010, this study finds a strong association between several measures of IPO performance and the familiarity between the lead underwriter and its counsel, as measured by the number of times a particular law firm serves as counsel to a managing underwriter within a relatively short time period. Performance is gauged according to a stock’s opening day returns, price performance over thirty, sixty, and ninety trading days, correct price revision, litigation rates, and the speed at which deals are completed. I also analyze the relationships between the lawyers for the lead underwriter and the lawyers for the issuer. The analysis shows some benefits from familiarity, albeit generally smaller than those associated with the underwriter-lawyer relationship. In all cases, the positive effects of repeated interaction diminish the further back in time the previous collaborations occurred. I also show that the relationships between familiarity and deal quality occur independently of the level of the lawyers’ experience. These findings support the conclusion that lawyers’ relational skill can positively influence deal outcomes, independent even of substance and process knowledge. I hypothesize that the core advantage of repeated interaction is the formation of more effective lawyer-client team dynamics.
Mild Hypercapnia Induces Vasodilation via Adenosine Triphosphate-sensitive K+ Channels in Parenchymal Microvessels of the Rat Cerebral Cortex

Background Carbon dioxide is an important vasodilator of cerebral blood vessels. Cerebral vasodilation mediated by adenosine triphosphate (ATP)-sensitive K+ channels has not been demonstrated in precapillary microvessel levels. Therefore, the current study was designed to examine whether ATP-sensitive K+ channels play a role in vasodilation induced by mild hypercapnia in precapillary arterioles of the rat cerebral cortex. Methods Brain slices from rat cerebral cortex were prepared and superfused with artificial cerebrospinal fluid, including normal (Pco2 = 40 mmHg; pH = 7.4), hypercapnic (Pco2 = 50 mmHg; pH = 7.3), and hypercapnic normal pH (Pco2 = 50 mmHg; pH = 7.4) solutions. The ID of a cerebral parenchymal arteriole (5–9.5 &mgr;m) was monitored using computerized videomicroscopy. Results During contraction to prostaglandin F2&agr; (5 × 10−7 m), hypercapnia, but not hypercapnia under normal pH, induced marked vasodilation, which was completely abolished by the selective ATP-sensitive K+ channel antagonist glibenclamide (5 × 10−6 m). However, the selective Ca2+-dependent K+ channel antagonist iberiotoxin (10−7 m) as well as the nitric oxide synthase inhibitor NG-nitro-l-arginine methyl ester (10−4 m) did not alter vasodilation. A selective ATP-sensitive K+ channel opener, levcromakalim (3 × 10−8 to 3 × 10−7 m), induced vasodilation, whereas this vasodilation was abolished by glibenclamide. Conclusion These results suggest that in parenchymal microvessels of the rat cerebral cortex, decreased pH corresponding with hypercapnia, but not hypercapnia itself, contributes to cerebral vasodilation produced by carbon dioxide and that ATP-sensitive K+ channels play a major role in vasodilator responses produced by mild hypercapnia.
Effect of storage conditions on the survival of two potential biocontrol agents of nematodes, the fungi Paecilomyces lilacinus and Pochonia chlamydosporia

Abstract The nematophagous fungi Paecilomyces lilacinus and Pochonia chlamydosporia have been extensively studied as biological control agents for plant-parasitic nematodes. This study describes the formulation of alginate pellets containing mycelia of these fungi and also describes the effect of storage conditions on shelf-life of the pellets. The shelf-lives of P. lilacinus and P. chlamydosporia, which were measured monthly for 6 months, were significantly improved at low temperatures and low water activity (a w) values (<0.33). Vacuum did not affect the viability of the formulated P. lilacinus but increased the viability of P. chlamydosporia. Carbon dioxide reduced the activity of P. lilacinus as compared to ambient air but increased the activity of P. chlamydosporia. Nitrogen, however, significantly improved the viability of both fungi. The optimal parameters of each factor for our formulation of P. lilacinus and P. chlamydosporia included a temperature range of 4 to −20°C, a w=0.12, and a nitrogen-filled atmosphere.
Simulations of Stellar Collisions Involving Pre-Main-Sequence Stars

In this paper, we present the results of smoothed particle hydrodynamic (SPH) simulations of collisions between pre-main-sequence stars and a variety of other kinds of stars. Simulations over a range of impact parameters and velocities were performed. We find that pre-main-sequence stars tend to "wrap" themselves around their impactor. We discuss the probable evolutionary state of products of collisions between pre-main-sequence stars and pre-main-sequence, main-sequence, giant branch, and compact stars. The nature of the collision product does not depend strongly on the impact parameter or the velocity of the collision.
Integrating a Hypertext Interface into a Syntax-Directed Programming Environment

This paper describes an integration of hypertext browsing and authoring facilities into a syntax-directed programming environment. The editor’s recognition of the programming language building blocks has been exploited not only to guide program entry, but to break programs into units which can be connected into a hyperdocument. Comments and documentation are separated from the actual program and integrated into this hyperdocument to provide an explanatory hypertext view through which programs can be navigated. The environment also incorporates a flexible history record mechanism deployed at appropriate points in the program structure, rather than only at the file level as with many current programming environments.
The Impact of Lbos on Investment Policies and Operations of Acquired French Firms

This paper evaluates the extent that French LBO targets' investment policy and operations can account for their overperformance discrepancy. Our empirical study has been carried out on 132 French LBOs between 1989 and 1994. The results show that the abnormal plunge in economic return cannot be explained by overinvestments or by inefficient working capital management. Nevertheless, abnormal increases in wages, supplies and/or sales price reductions appear to be prominent.
The Polygon Exploration Problem II: The Angle Hull

Let D be a connected region inside a simple polygon, P. We define the angle hull of D, AH(D), to be the set of all points in P that can see two points of D at a right angle. We show that the perimeter of AH(D) cannot exceed in length the perimeter of D by more than a factor of 2. This upper bound is tight. Our result can be generalized to angles different from 90°, and to settings where region D is surrounded by obstacles other than a simple polygon.
Wireless Communications and Spectrum Characterization in Impaired Channel Environments

The demand for sophisticated wireless applications capable of conveying information content represented in various forms such as voice, data, audio and video is ever increasing. In order to support such applications, either additional wireless spectrum is needed or advanced signal processing techniques must be employed by the next-generation wireless communication systems. An immediate observation that can be made regarding the first option is that radio frequency spectrum is a limited natural resource. Moreover, since existing spectrum allocation policies of several national regulatory agencies such as the Federal Communications Commission (FCC) restrict spectrum access to licensed entities only, it has been identified that most of the licensed spectrum across time and frequency is inefficiently utilized. To facilitate greater spectral efficiency, many national regulatory agencies are considering a paradigm shift towards spectrum allocation by allowing unlicensed users to temporarily borrow unused spectral resources. This concept is referred to a dynamic spectrum access (DSA). Although, several spectrum measurement campaigns have been reported in the published literature for quantitatively assessing the available vacant spectrum, there are certain aspects of spectrum utilization that need a deeper understanding. First, we examine two complementary approaches to the problem of characterizing the usage of licensed bands. In the first approach, a linear mixed-effects based regression model is proposed, where the variations in percentage spectrum occupancy and activity period of the licensed user are described as a function of certain independent regressor variables. The second approach is based on the creation of a geo-location database consisting of the licensed transmitters in a specific geographical region and identifying the coverage areas that affect the available secondary channels. Both of these approaches are based on the energy spectral density data-samples collected across numerous frequency bands in several locations in the United States. We then study the mutual interference effects in a coexistence scenario consisting of licensed and unclicensed users. We numerically evaluate the impact of interference as a function of certain receiver characteristics. Specifically, we consider the unlicensed user to utilize OFDM or NOFDM symbols since the appropriate subcarriers can be turned off to facilitate non-contiguous spectrum utilization. Finally, it has been demonstrated that multiple-input and multiple-output (MIMO) antennas yield significant throughput while requiring no increase in transmit power or required bandwidth. However, the separation of spectrally overlapping signals is a challenging task that involves
Capture the flag: simulating a location-based mobile game using the wizard-of-oz method

We present a wizard of Oz framework for the simulation of location-based mobile games. We explore briefly the methodological concept of Wizard of Oz and show, based on a case study, advantages and shortcomings of the method. The case study realized a game called capture-the-flag. We show how such prototypes can be evaluated in a real field trial.
Adapting the sampling period of a real-time adaptive distributed controller to the bus load

This paper presents a new method to allow more flexibility on the scheduling of messages across a fieldbus in overload situations. The method proposes the on-line adaptation of the sampling period to the bus load, trying to keep it as low as possible during overloads. The sampling period is allowed to change inside an interval corresponding to 4 to 10 samples per rise time. To assess the solution herein presented, a distributed adaptive control system was implemented in TrueTime, using the FTT-CAN protocol, for the communication infrastructure, a pole-placement controller and a model for the identification of plant parameters that takes into account the network-induced jitter
Epoxy-Based Shape-Memory Actuators Obtained via Dual-Curing of Off-Stoichiometric “Thiol–Epoxy” Mixtures

In this work, epoxy-based shape-memory actuators have been developed by taking advantage of the sequential dual-curing of off-stoichiometric “thiol–epoxy” systems. Bent-shaped designs for flexural actuation were obtained thanks to the easy processing of these materials in the intermediate stage (after the first curing process), and successfully fixed through the second curing process. The samples were programmed into a flat temporary-shape and the recovery-process was analyzed in unconstrained, partially-constrained and fully-constrained conditions using a dynamic mechanical analyzer (DMA). Different “thiol–epoxy” systems and off-stoichiometric ratios were used to analyze the effect of the network structure on the actuation performance. The results evidenced the possibility to take advantage of the flexural recovery as a potential actuator, the operation of which can be modulated by changing the network structure and properties of the material. Under unconstrained-recovery conditions, faster and narrower recovery-processes (an average speed up to 80%/min) are attained by using materials with homogeneous network structure, while in partially- or fully-constrained conditions, a higher crosslinking density and the presence of crosslinks of higher functionality lead to a higher amount of energy released during the recovery-process, thus, increasing the work or the force released. Finally, an easy approach for the prediction of the work released by the shape-memory actuator has been proposed.
Spatial Coordinate Coding to reduce histogram representations, Dominant Angle and Colour Pyramid Match

Spatial Pyramid Match lies at a heart of modern object category recognition systems. Once image descriptors are expressed as histograms of visual words, they are further deployed across spatial pyramid with coarse-to-fine spatial location grids. However, such representation results in extreme histogram vectors of 200K or more elements increasing computational and memory requirements. This paper investigates alternative ways of introducing spatial information during formation of histograms. Specifically, we propose to apply spatial location information at a descriptor level and refer to it as Spatial Coordinate Coding. Alternatively, x, y, radius, or angle is used to perform semi-coding. This is achieved by adding one of the spatial components at the descriptor level whilst applying Pyramid Match to another. Lastly, we demonstrate that Pyramid Match can be applied robustly to other measurements: Dominant Angle and Colour. We demonstrate state-of-the art results on two datasets with means of Soft Assignment and Sparse Coding.
Nanomaterials—Tools, Technology and Methodology of Nanotechnology Based Biomedical Systems for Diagnostics and Therapy

Nanomedicine helps to fight diseases at the cellular and molecular level by utilizing unique properties of quasi-atomic particles at a size scale ranging from 1 to 100 nm. Nanoparticles are used in therapeutic and diagnostic approaches, referred to as theranostics. The aim of this review is to illustrate the application of general principles of nanotechnology to select examples of life sciences, molecular medicine and bio-assays. Critical aspects relating to those examples are discussed.
Towards the establishment of supporting mechanisms for modeling and generating educational content

Content modeling plays a fundamental role in the development of educational modules, helping the author to determine the main concepts to be taught and providing a systematic way to structure the relevant parts of the knowledge domain. Despite its relevance, there are few approaches for modeling educational content. In this perspective, an integrated approach for content modeling, named IMA--CID, was proposed. IMA--CID is composed of a set of models, each one considering specific aspects of the development of educational content; however, applying it without an automated support can be an error-prone activity. Motivated by this scenario, in this paper we describe IMATool -- a supporting tool for content modeling, particularly designed for helping the open and distributed construction of the EMAIL@IMA--CID models. Mechanisms for content generation are also available. We illustrate our ideas by applying IMA--CID and IMATool in the development of an educational module for the software testing domain. The preliminary results obtained provide evidences on the practical use of such mechanisms for modeling and generating content.
Tumor Necrosis Factor – a Production to Lipopolysaccharide Stimulation by Donor Cells Predicts the Severity of Experimental Acute Graft-Versus-Host Disease

Donor T cell responses to host alloantigen are known predictors for graft-versus-host disease (GVHD); however, the effect of donor responsiveness to an inflammatory stimulus such as lipopolysaccharide (LPS) on GVHD severity has not been investigated. To examine this, we used mouse strains that differ in their sensitivity to LPS as donors in an experimental bone marrow transplant (BMT) system. Lethally irradiated (C3FeB6)F1 hosts received BMT from either LPSsensitive (LPS-s) C3Heb/Fej, or LPS-resistant (LPS-r) C3H/ Hej donors. Mice receiving LPS-r BMT developed significantly less GVHD as measured by mortality and clinical score compared with recipients of LPS-s BMT, a finding that was associated with significant decreases in intestinal histopathology and serum LPS and TNFa levels. When donor T cell responses to host antigens were measured, no differences in proliferation, serum IFNg levels, splenic T cell expansion, or CTL activity were observed after LPS-r or LPS-s BMT. Systemic neutralization of TNFa from day 2 2 to 1 6 resulted in decreased intestinal pathology, and serum LPS levels and increased survival after BMT compared with control mice receiving Ig. We conclude that donor resistance to endotoxin reduces the development of acute GVHD by attenuating early intestinal damage mediated by TNF a . These data suggest that the responsiveness of donor accessory cells to LPS may be an important risk factor for acute GVHD severity independent of T cell responses to host antigens. ( J. Clin. Invest. 1998. 102:1882–1891.)
Bacillus subtilis Spores Germinate in the Chicken Gastrointestinal Tract

ABSTRACT A number of poultry probiotics contain bacterial spores. In this study, orally administered spores of Bacillus subtilis germinated in the gastrointestinal (GI) tracts of chicks. Furthermore, 20 h after spores were administered, vegetative cells outnumbered spores throughout the GI tract. This demonstrates that spore-based probiotics may function in this host through metabolically active mechanisms.