STUDIES ON NATURAL AND EDIBLE BIOPOLYMERS. ISOLATION, CHARACTERIZATION AND CHEMICAL MODIFICATIONS OF POLY(Γ-GLUTAMIC ACID) (Γ-PGA) FROM BACILLUS SUBTILIS

Poly(\u3b3-glutamic acid) (\u3b3-PGA) is a unusual anionic, water-soluble homopolyamide composed of D- and/or L-glutamic acid monomers, connected by amide bonds between \u3b1-amino and \u3b3-carboxyl groups, mainly produced by Gram-positive bacteria of the genus Bacillus. \u3b3-PGA is hygroscopic and water-soluble; in the salt form is able to form gels containing water in more than 3,000 times its weight. It is fairly resistant to hydrolysis, although it is degraded in basic medium at high temperature; it appears to be insensitive to common proteases such as pepsin or tripsin. \u3b3-PGA is completely innocuous and edible. The popular food known as natto in Japan or dan-douchi in China, a soybean fermented compound that contains about 1% of \u3b3-PGA, has formed part of the diet of Asian people for hundreds of years. Due to its biodegradability and to the intrinsic absence of toxicity as well as to the classification as GRAS (Generally Regarded As Safe) of the main producers, i.e. Bacilli, \u3b3-PGA represents one of the naturally occurring polymers of interest for the production of environmentally friendly derivatives. Although having been known and even used for industrial applications for a long time, and considerable efforts having been spent in investigating its chemical and biological properties, much lies ahead to be elucidated about this polymer biosynthesis and conformational aspects. In addition, its potential applications appear to be still almost unexploited in the Western world. This Ph.D. thesis deals with the bioproduction, characterization and derivatization of \u3b3-PGA from Bacillus subtilis in order to obtain novel biomaterials useful for biopackaging, biomolecule immobilization, and as drug carriers. In particular, the problems we have addressed were: the optimization of productivity, by means of genetic engineering technologies; the characterization of the polymer, with regard to its stereochemical composition and molecular weight, which deeply affect its chemical-physical properties and reactivity; the development of effective methodologies for chemical modification of the polymer, in view of preparing derivatives of pharmaceutical and technological interest. Finally, we also established a synthetic approach for the preparation of standard samples with controlled stereochemistry necessary for conformational studies

Diffusive transport of light in two-dimensional granular materials

We study photon diffusion in a two-dimensional random packing of monodisperse disks as a simple model of granular material. We apply ray optics approximation to set up a persistent random walk for the photons. We employ Fresnel's intensity reflectance with its rich dependence on the incidence angle and polarization state of the light. We present an analytic expression for the transport-mean-free path in terms of the refractive indices of grains and host medium, grain radius, and packing fraction. We perform numerical simulations to examine our analytical result.Comment: 9 pages, 3 figure

Hand Rehabilitation and Telemonitoring through Smart Toys

We describe here a platform for autonomous hand rehabilitation and telemonitoring of young patients. A toy embedding the electronics required to sense fingers pressure in different grasping modalities is the core element of this platform. The system has been realized following the user-centered design methodology taking into account stakeholder needs from start: clinicians require reliable measurements and the ability to get a picture remotely on rehabilitation progression; children have asked to interact with a pleasant and comfortable object that is easy to use, safe, and rewarding. These requirements are not antithetic, and considering both since the design phase has allowed the realization of a platform reliable to clinicians and keen to be used by young children

Validity and usability of a smart ball–driven serious game to monitor grip strength in independent elderlies

Telemonitoring is one of the most expedient answers to the strong need for preventive care imposed by the rapidly aging society. We propose an innovative solution to the detection of early signs of frailty by presenting a serious game controlled by a smart sensorized soft plastic ball, designed to achieve continuous home-based monitoring of muscle weakness in older adults. Design, development, and testing of the smart ball and of the game interface devised to guide the monitoring procedure are presented. Reliability and concurrent validity of the system in measuring maximal grip strength against the clinical standard Jamar\uae were evaluated. Serious game usability and acceptance were investigated on 26 elderlies. Smart ball and Jamar measurements were well correlated (0.76 and 0.80 for dominant and non-dominant hands) and test\u2013retest reliability of pressure measurements was excellent (intraclass correlation coefficient >0.94). The serious game was well accepted by the 96.1 percent of participants, who provided a strongly positive usability score (87.7/100). The smart ball\u2013driven serious game demonstrated excellent reliability and good validity in measuring grip strength. The proposed smart ball\u2013driven serious game can be used for home self-monitoring of grip strength in elderlies

Using Virtual Reality to Rehabilitate Neglect

Purpose: Virtual Reality (VR) platforms gained a lot of attention in the rehabilitation field due to their ability to engage patients and the opportunity they offer to use real world scenarios. As neglect is characterized by an impairment in exploring space that greatly affects daily living, VR could be a powerful tool compared to classical paper and pencil tasks and computer training. Nevertheless, available platforms are costly and obstructive. Here we describe a low cost platform for neglect rehabilitation, that using consumer equipments allows the patient to train at home in an intensive fashion. Method: We tested the platform on IB, a chronic neglect patient, who did not benefit from classical rehabilitation. Results: Our results show that IB improved both in terms of neglect and attention. Importantly, these ameliorations lasted at a follow up evaluation 5 months after the last treatment session and generalized to everyday life activities. Conclusions: VR platforms built using equipment technology and following theoretical principles on brain functioning may induce greater ameliorations in visuo-spatial deficits than classical paradigms possibly thanks to the real world scenarios in association with the "visual feedback" of the patient's own body operating in the virtual environmen

Minimal Stability in Maximal Supergravity

Recently, it has been shown that maximal supergravity allows for non-supersymmetric AdS critical points that are perturbatively stable. We investigate this phenomenon of stability without supersymmetry from the sGoldstino point of view. In particular, we calculate the projection of the mass matrix onto the sGoldstino directions, and derive the necessary conditions for stability. Indeed we find a narrow window allowing for stable SUSY breaking points. As a by-product of our analysis, we find that it seems impossible to perturb supersymmetric critical points into non-supersymmetric ones: there is a minimal amount of SUSY breaking in maximal supergravity.Comment: 27 pages, 1 figure. v2: two typos corrected, published versio

Effect of two different source of forage on the organic matter digestibility in Mediterranean Italian Buffalo cows

The present study aimed to evaluate the influence of two different source of forage (haysilage and hay) during the lactation on organic matter digestibility (OMD) in buffalo cows. Lactating buffaloes (n = 40) at 29.6 days in milk (DIM) were equally divided as function of previous milk yield into Group 1 (meadow hay, n = 20) and Group 2 [haysilage (Lolium multiflorum), n = 20]. The diets were isoenergetic [0.92 milk unit forage (MUF) on dry matter basis] and isoproteic (16.2 % crude protein on dry matter basis) and administred as total mixed ration (TMR). From all the buffaloes, for each group and in two sampling time (first sampling, DIM = 74.0 and second sampling, DIM = 129.0) the faeces were collected in order to evaluate the in vivo digestibility. Overall the trial, the subjects fed haysilage showed higher OMD than those fed hay (66.1 vs 45.7; P<0.01), moreover the in vivo digestibility was affected by the DIM, in particular in the group fed hay (40.6 vs 53.4; P<0.0001, respectively). This work underlines the importance of the administration of the haysilage (Lolium multiflorum) as source of high quality forage because it gives, overall the lactation, more nutritive principles compared with meadow hay

Appeal No. 0873: Stonebridge Operating Co., LLC. v. Division of Oil & Gas Resources Management

Chief\u27s Orders 2014-39 (suspension of operations); 2014-236, 2014-238,2014-239, 2014-241 (denials of plug-back permits); 2014-253, 2014-256 thru 2014-262 & 2014-264 thru 2014-266 (plug orders