On sorting triangles in a delaunay tessellation

In a two-dimensional Delaunay-triangulated domain, there exists a partial ordering of the triangles (with respect to a vertex) that is consistent with the two-dimensional visibility of the triangles from that vertex. An equivalent statement is that a polygon that is star-shaped with respect to a given vertex can be extended, one triangle at a time, until it includes the entire domain. Arbitrary planar triangulations do not possess this useful property which allows incremental processing of the triangles.This work was partially supported by the National Science Foundation's US-Italy Collaborative Research Program under Grant INT-8714578 and Information, Robotics, and Intelligent Research Grant IRI-8704781.     

Immobilization of an endopectinlyase on γ-alumina: Study of factors influencing the biocatalytic matrix stability

Endopectinlyase (EC 4.2.2.10) from Aspergillus japonicus was immobilized on to γ-alumina. Adsorption performed at pH 5·0 and a subsequent cross-linking phase using 0·1% glutaraldehyde were the chosen immobilization conditions. The comparison between the main biochemical parameters of the immobilized and free form of the enzyme showed that the immobilization procedure used did not affect the enzyme biochemical properties. The interactions between the carrier and the enzyme are essentially secondary bonding. In fact they depend on the pH and on the presence of phosphate ions in the medium. A tentative chemical model of the biocatalytic matrix thus obtained is proposed.     

Chaotic pulse position modulation to improve the efficiency of sonar sensors

Ultrasonic devices are widely used in robotics as exteroceptive sensors for ranging measurements. Robotic applications often involve a large number of sonars operating concurrently, giving rise to the phenomenon of crosstalk. In this work, the problem of improving performance of ultrasonic devices in the presence of crosstalk and noise is addressed. In order for each device to discriminate its own echo, chaos is exploited to create unique firing sequences. In particular, the firing scheme described in this work is inspired to a modulation scheme used in chaotic communications, called chaotic pulse position modulation (CPPM). The evaluation of the time of flight is performed by a detection filter. The experimental setup consists of a Polaroid 600 electrostatic transducer driven by a continuous CPPM modulator. Experimental results confirm the suitability of the approach.     

Reward only is not enough: Evaluating and improving the fairness policy of the P2P file sharing network eMule/eDonkey

Limiting the threat of free-riding behavior is an important design issue for peer-to-peer (P2P) file sharing networks. However, the fairness policy that rewards contributors with credit in one of the most popular P2P file sharing networks, eMule/eDonkey, hasn’t been thoroughly studied. In this paper, motivated by our experiments with the eMule/eDonkey network, we firstly theoretically analyze the content exchange process with credit in eMule/eDonkey and then verify the mathematical model by an agent-based simulation. Both the numerical and simulation-based results confirm our discovery in the experiments that eMule/eDonkey’s local credit strategy can not provide enough fairness as it doesn’t explicitly punish free-riders. To overcome this drawback, we propose a new free-riding control scheme, which can simply maintain the current credit local structure and take advantage of the credit policy. Extensive numerical evaluation and simulation indicate that this scheme significantly improves system fairness.     

Development of a virtual reality laboratory stressor

Virtual Reality - This research report describes the development of a virtual reality (VR) laboratory stressor to study the effects of exposure to stressful events. The aim of the research was to...     

Ion Channels and Electroosmosis in Porous Geopolymers: A Novel Category of Low-Cost Memristors

Memristors are electric components that emulate the memory and computational properties of biological synapses by remembering the current that flows through them. Here, for the first time, the memristive properties of geopolymers, inexpensive ceramic materials manufactured at room temperature from alkaline activation of amorphous aluminosilicate precursors, are presented. It is demonstrated that geopolymers present all the fingerprints of memristors, and a physics-based model is proposed, which demonstrates that electroosmosis in the bulk geopolymer pores induces ion channels that foster change in the overall conductance of the bulk material, contributing to the observed memristive behavior. This model opens the door to a new category of porous electroosmosis-based bulk memristors. Synaptic functions such as short-term plasticity and long-term plasticity, as well as endurance and retention capabilities are also demonstrated. The reported findings pave the way to the use of geopolymers for low-cost applications in neuromorphic computing.     

Diagnosing attention disorders in a virtual classroom

The virtual classroom provides an efficient and scalable tool for conducting attention testing. The University of Southern California integrated media systems center and digital media works have partnered to develop virtual reality technology applications for the study, assessment, and rehabilitation of cognitive and functional processes. This work primarily focuses on the development of systems that address the special needs of clinical populations with central nervous system dysfunctions such as brain injury, learning disabilities, or neurological disorders.     

Fascial Innervation: A Systematic Review of the Literature

Currently, myofascial pain has become one of the main problems in healthcare systems. Research into its causes and the structures related to it may help to improve its management. Until some years ago, all the studies were focused on muscle alterations, as trigger points, but recently, fasciae are starting to be considered a new, possible source of pain. This systematic review has been conducted for the purpose of analyze the current evidence of the muscular/deep fasciae innervation from a histological and/or immunohistochemical point of view. A literature search published between 2000 and 2021 was made in PubMed and Google Scholar. Search terms included a combination of fascia, innervation, immunohistochemical, and different immunohistochemical markers. Of the 23 total studies included in the review, five studies were performed in rats, four in mice, two in horses, ten in humans, and two in both humans and rats. There were a great variety of immunohistochemical markers used to detect the innervation of the fasciae; the most used were Protein Gene Marker 9.5 (used in twelve studies), Calcitonin Gene-Related Peptide (ten studies), S100 (ten studies), substance P (seven studies), and tyrosine hydroxylase (six studies). Various areas have been studied, with the thoracolumbar fascia being the most observed. Besides, the papers highlighted diversity in the density and type of innervation in the various fasciae, going from free nerve endings to Pacini and Ruffini corpuscles. Finally, it has been observed that the innervation is increased in the pathological fasciae. From this review, it is evident that fasciae are well innerved, their innervation have a particular distribution and precise localization and is composed especially by proprioceptors and nociceptors, the latter being more numerous in pathological situations. This could contribute to a better comprehension and management of pain.     

Platelet Derivatives and the Immunomodulation of Wound Healing

Besides their primary role in hemostasis, platelets contain a plethora of immunomodulatory molecules that profoundly affect the entire process of wound repair. Therefore, platelet derivatives, such as platelet-rich plasma or platelet lysate, have been widely employed with promising results in the treatment of chronic wounds. Platelet derivatives provide growth factors, cytokines, and chemokines targeting resident and immigrated cells belonging to the innate and adaptive immune system. The recruitment and activation of neutrophils and macrophages is critical for pathogen clearance in the early phase of wound repair. The inflammatory response begins with the release of cytokines, such as TGF-β, aimed at damping excessive inflammation and promoting the regenerative phase of wound healing. Dysregulation of the immune system during the wound healing process leads to persistent inflammation and delayed healing, which ultimately result in chronic wound. In this review, we summarize the role of the different immune cells involved in wound healing, particularly emphasizing the function of platelet and platelet derivatives in orchestrating the immunological response.