3,834 research outputs found
Synergy-based Hand Pose Sensing: Reconstruction Enhancement
Low-cost sensing gloves for reconstruction posture provide measurements which
are limited under several regards. They are generated through an imperfectly
known model, are subject to noise, and may be less than the number of Degrees
of Freedom (DoFs) of the hand. Under these conditions, direct reconstruction of
the hand posture is an ill-posed problem, and performance can be very poor.
This paper examines the problem of estimating the posture of a human hand
using(low-cost) sensing gloves, and how to improve their performance by
exploiting the knowledge on how humans most frequently use their hands. To
increase the accuracy of pose reconstruction without modifying the glove
hardware - hence basically at no extra cost - we propose to collect, organize,
and exploit information on the probabilistic distribution of human hand poses
in common tasks. We discuss how a database of such an a priori information can
be built, represented in a hierarchy of correlation patterns or postural
synergies, and fused with glove data in a consistent way, so as to provide a
good hand pose reconstruction in spite of insufficient and inaccurate sensing
data. Simulations and experiments on a low-cost glove are reported which
demonstrate the effectiveness of the proposed techniques.Comment: Submitted to International Journal of Robotics Research (2012
Synergy-Based Hand Pose Sensing: Optimal Glove Design
In this paper we study the problem of improving human hand pose sensing
device performance by exploiting the knowledge on how humans most frequently
use their hands in grasping tasks. In a companion paper we studied the problem
of maximizing the reconstruction accuracy of the hand pose from partial and
noisy data provided by any given pose sensing device (a sensorized "glove")
taking into account statistical a priori information. In this paper we consider
the dual problem of how to design pose sensing devices, i.e. how and where to
place sensors on a glove, to get maximum information about the actual hand
posture. We study the continuous case, whereas individual sensing elements in
the glove measure a linear combination of joint angles, the discrete case,
whereas each measure corresponds to a single joint angle, and the most general
hybrid case, whereas both continuous and discrete sensing elements are
available. The objective is to provide, for given a priori information and
fixed number of measurements, the optimal design minimizing in average the
reconstruction error. Solutions relying on the geometrical synergy definition
as well as gradient flow-based techniques are provided. Simulations of
reconstruction performance show the effectiveness of the proposed optimal
design.Comment: Submitted to International Journal of Robotics Research 201
The potential role of vitamin D for prevention and treatment of tuberculosis and infectious diseases
INTRODUCTION: Vitamin D deficiency (VDD) is a common condition among several populations in the world. VDD is associated with higher incidence of immune system disorders and faster progression of some infectious diseases. Vitamin D is known to be of physiological importance, it is considered an essential micronutrient for the bone health and plays a beneficial role in the prevention and/or treatment of a number of chronic diseases. Vitamin D has a complex action on the immune system. RESULTS: Evidence that vitamin D protects against tuberculosis has been supported by in vitro, epidemiological and some preliminary clinical studies. Vitamin D has a potential effect on HIV (human immunodeficiency virus) and plays a crucial role in the defence against respiratory infections. CONCLUSIONS: Vitamin D supplementation could be a low-cost, practical method to protect groups of people with high incidence of those diseases. Public health education should stress the need for adequate dietary intake of vitamin D in those vulnerable groups
How HEXACO personality traits predict different selfie-posting behaviors among adolescents and young adults
Selfies are usually defined as self-portrait photos shared on social networks. Recent studies investigated how personality traits, and specifically narcissism, can be associated to different kinds of selfies. The HEXACO model, a new theory on personality structure, investigates personality on six dimensions, among which there is the Honesty/Humility trait, found strongly and negatively associated to narcissism. Thus, this study aims to investigate how different kinds of selfies could be predicted by HEXACO personality traits, controlling for age, gender and sexual orientation. Participants were 750 adolescents and young adults (59.1% girls, N = 443) from 13 to 30 years (Mage = 20.96; SDage = 4.23) who completed an online survey composed by the Kinsey scale, three questions about the frequency of different kinds of selfies (i.e. own selfies, group selfies and selfies with partner) and 60-item Hexaco Personality Inventory-Revised. Results showed that females, adolescents and not- exclusively heterosexuals posted more own selfies, and that adolescents posted also more group selfies and selfies with partner. Moreover lower Honesty/Humility, lower Conscientiousness, higher Emotionality and higher Extraversion significantly predict both own selfies and group selfies. Finally, only lower Honesty/Humility and higher Emotionality predict selfies with partner. Results suggested a common pattern of personality traits that can explain selfies behaviors according to literature on HEXACO model. Specifically, these findings enlightened that Honesty/Humility and Emotionality traits seem to be relevant in understanding selfies. People who post more selfies are lower in Honesty/Humility, showing a strong sense of self-importance and feeling superior. Moreover, they show higher Emotionality that is related to looking for social reinforcement on social networks. Only for own and group selfies, people high in Extraversion probably feel self-confident in groups, also in the online dimension, and low extraverted people probably posted less frequently because they feel uncomfortable being at the center of attention. Finally, people with high Conscientiousness spend less time online because they consider social networks as a distraction from their tasks. Thus, HEXACO model allows to better understand which personality traits can predict different kinds of selfies. Limitations and implications for future research are discussed
Electrical Conductivity Criteria in Polyiodides Networks: Stunning Architectures in the Solid State
Inorganic Nanomaterials in Tissue Engineering
In recent decades, the demand for replacement of damaged or broken tissues has increased;
this poses the attention on problems related to low donor availability. For this reason, researchers
focused their attention on the field of tissue engineering, which allows the development of scaffolds
able to mimic the tissues’ extracellular matrix. However, tissue replacement and regeneration are
complex since scaffolds need to guarantee an adequate hierarchical structured morphology as well
as adequate mechanical, chemical, and physical properties to stand the stresses and enhance the
new tissue formation. For this purpose, the use of inorganic materials as fillers for the scaffolds has
gained great interest in tissue engineering applications, due to their wide range of physicochemical
properties as well as their capability to induce biological responses. However, some issues still need
to be faced to improve their efficacy. This review focuses on the description of the most effective
inorganic nanomaterials (clays, nano-based nanomaterials, metal oxides, metallic nanoparticles) used
in tissue engineering and their properties. Particular attention has been devoted to their combination
with scaffolds in a wide range of applications. In particular, skin, orthopaedic, and neural tissue
engineering have been considered.Horizon 2020 Research and Innovation Programme 81460
Cerium Oxide and Chondroitin Sulfate Doped Polyurethane Scaffold to Bridge Tendons
Tendon disorders are common medical conditions,
which can be greatly debilitating as they are often accompanied by
great pain and inflammation. The techniques used nowadays for
the treatment of chronic tendon injuries often involve surgery.
However, one critical aspect of this procedure involves the scar
tissue, characterized by mechanical properties that vary from
healthy tissue, rendering the tendons inclined to reinjury or
rupture. Synthetic polymers, such as thermoplastic polyurethane,
are of special interest in the tissue engineering field as they allow
the production of scaffolds with controlled elastic and mechanical
properties, which could guarantee an effective support during the
new tissue formation. The aim of this work was the design and the
development of tubular nanofibrous scaffolds based on thermoplastic
polyurethane and enriched with cerium oxide nanoparticles and chondroitin sulfate. The scaffolds were characterized by
remarkable mechanical properties, especially when tubular aligned, reaching values comparable to the ones of the native tendons. A
weight loss test was performed, suggesting a degradation in prolonged times. In particular, the scaffolds maintained their morphology
and also remarkable mechanical properties after 12 weeks of degradation. The scaffolds promoted the cell adhesion and proliferation,
in particular when in aligned conformation. Finally, the systems in vivo did not cause any inflammatory effect, representing
interesting platforms for the regeneration of injured tendons.Horizon 2020 Research and Innovation Programme under
Grant Agreement No. 81460
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