Generalized Holographic Principle, Gauge Invariance and the Emergence of Gravity a la Wilczek

We show that a generalized version of the holographic principle can be derived from the Hamiltonian description of information flow within a quantum system that maintains a separable state. We then show that this generalized holographic principle entails a general principle of gauge invariance. When this is realized in an ambient Lorentzian space-time, gauge invariance under the Poincare group is immediately achieved. We apply this pathway to retrieve the action of gravity. The latter is cast a la Wilczek through a similar formulation derived by MacDowell and Mansouri, which involves the representation theory of the Lie groups SO(3,2) and SO(4,1).Comment: 26 pages, 1 figur

Near-surface processing on AlGaN/GaN heterostructures: a nanoscale electrical and structural characterization

The effects of near-surface processing on the properties of AlGaN/GaN heterostructures were studied, combining conventional electrical characterization on high-electron mobility transistors (HEMTs), with advanced characterization techniques with nanometer scale resolution, i.e., transmission electron microscopy, atomic force microscopy (AFM) and conductive atomic force microscopy (C-AFM). In particular, a CHF3-based plasma process in the gate region resulted in a shift of the threshold voltage in HEMT devices towards less negative values. Two-dimensional current maps acquired by C-AFM on the sample surface allowed us to monitor the local electrical modifications induced by the plasma fluorine incorporated in the material

Zespół padaczkowy z drgawkami połowiczymi i porażeniem połowiczym. Wyniki badania za pomocą rezonansu magnetycznego u trzyletniego chłopca

The term ‘hemiconvulsion-hemiplegia-epilepsy syndrome’ (HHE) was first used by Gastaut et al. to describe the sequential combination of unilateral or predominandy unilateral clonic seizures (hemiconvulsion), occurring during the first 2 years of life, immediately followed by an ipsilateral flaccid hemiplegia lasting 7 or more days. In the following phase partial epileptic seizures occur. We report a case of HHE syndrome in a 3-year-old boy with partial seizures (hemiconvulsion lasting 15–30 minutes) followed by left hemiplegia and hyporeflexia. Magnetic resonance imaging showed diffuse and high signal hyperintensity of the whole right cerebral hemisphere. Diffusion-weighted images showed a reduction of the apparent diffusion coefficient in the subcortical region. Magnetic resonance arteriography showed a narrow flow signal in the distal territory of the right middle cerebral artery. The authors emphasize the importance of neuroradiological findings in early diagnosis and in the follow-up of HHE syndrome.Określenia zespół padaczkowy z drgawkami połowiczymi i z porażeniem połowiczym” (hemiconvulsion-hemiplegia epilepsy – HHE) użyli po raz pierwszy Gastaut i wsp., aby opisać połączenie jednostronnych lub głównie jednostronnych drgawek klonicznych, pojawiających się w pierwszych dwóch latach życia, po których następuje tożstronne wiotkie porażenie połowicze utrzymujące się przez co najmniej tydzień. Następnie występują napady padaczkowe częściowe. W artykule przedstawiono przypadek zespołu HHE u trzyletniego chłopca z napadami częściowymi (drgawki połowicze trwające 15–30 minut), po których nastąpiło lewostronne porażenie połowicze z osłabionymi odruchami głębokimi. W badaniu za pomocą rezonansu magnetycznego uwidoczniono rozlane zmiany hiperintensywne w całej prawej półkuli mózgu. W obrazowaniu dyfuzji stwierdzono zmniejszenie współczynnika dyfuzji w obszarach podkorowych. W arteriografii rezonansu magnetycznego uwidoczniono wąski sygnał przepływu w dystalnych gałęziach prawej tętnicy środkowej mózgu. Autorzy podkreślają znaczenie wyników badań obrazowych układu nerwowego we wczesnym rozpoznaniu i obserwacji chorych na HHE

Frailty, Disability and Physical Exercise in the Aging Process and in Chronic Kidney Disease

Frailty in the elderly is a state of vulnerability to poor resolution of homoeostasis after a stressor event and is a consequence of cumulative decline in many physiological systems during a lifetime. This cumulative decline depletes homoeostatic reserves until minor stressor events trigger disproportionate changes in health status. It is usually associated to adverse health outcomes and to one-year mortality risk. Physical exercise has found to be effective in preventing frailty and disability in this population. Chronic kidney disease (CKD) is also a clinical condition where protein energy-wasting, sarcopenia and dynapenia ,very common symptoms in the frail elderly, may occur. Moreover elderly and CKD patients are both affected by an impaired physical performance that may be reversed by physical exercise with an improvement of the survival rate. These similarities suggest that frailty may be a common pathway of aging and CKD that may induce disability and that can be prevented by a multidimensional approach in which physical exercise plays an important role

Active dopant profiling and Ohmic contacts behavior in degenerate n-type implanted silicon carbide

This Letter reports on the active dopant profiling and Ohmic contact behavior in degenerate P-implanted silicon carbide (4H-SiC) layers. Hall measurements showed a nearly temperature-independent electron density, corresponding to an electrical activation of about 80% of the total implanted dose. Using the Hall result as calibration, the depth resolved active P-profile was extracted by scanning capacitance microscopy (SCM). Such information on the active P-profile permitted to elucidate the current injection mechanism at the interface of annealed Ni Ohmic contacts with the degenerate n-type 4H-SiC layer. Modeling the temperature dependence of the specific contact resistance with the thermionic field emission mechanism allowed extracting a doping concentration of 8.5 × 1019 cm−3 below the metal/4H-SiC interface, in excellent agreement with the value independently obtained by the SCM depth profiling. The demonstrated active dopant profiling methodology can have important implications in the 4H-SiC device technology

Information and Communication Technologies for the Activities of Daily Living in Older Patients with Dementia: A Systematic Review

Background: Significant innovations have been introduced in recent years in the application of information and communication technologies (ICTs) to support healthcare for patients with dementia. Objective: In the present systematic review, our goal is to keep track of ICT concepts and approaches to support the range of activities of daily living for people with dementia and to provide a snapshot of the effect that technology is having on patients' self-reliance. Methods: We reviewed the literature and identified systematic reviews of cohort studies and other authoritative reports. Our selection criteria included: (1) activities of daily living, (2) ICT, and (3) dementia. Results: We identified 56 studies published between 2000 and 2015, of which 26 met inclusion criteria. The present systematic review revealed many ICT systems that could purportedly support the range of activities of daily living for patients with dementia. The results showed five research bodies: 1) technologies used by patients with dementia, 2) technologies used by caregivers, 3) monitoring systems, 4) ambient assistive living with ICTs, and 5) tracking and wayfinding. Conclusions: There is a potential for ICTs to support dementia care at home and to improve quality of life for caregivers, reducing healthcare costs and premature institutional care for these patients

Isospin Dynamics in Peripheral Heavy Ion Collisions at Fermi Energies

We present a detailed study of isospin dynamics in peripheral collisions at Fermi energies. We consider symmetric and mixed collisions of (124,112)Sn isotopes at 35 and 50 AMeV to study the isospin transport between the different reaction components (residues, gas and possibly intermediate mass fragments) and, in particular, the charge equilibration in the mixed system. We evaluate the effects of drift terms due to asymmetry and density gradients, which are directly related to the poorly known value and slope of the symmetry energy below saturation density. We verify the importance of an isoscalar momentum dependence of the mean field, which is found to influence the isospin transport since it changes the reaction times. We finally suggest two observables particularly sensitive to the isovector part of the nuclear equation-of-state: the correlation between isospin equilibration and kinetic energy loss for binary events, and the isospin content of the produced mid-rapidity fragments for neck fragmentation events.Comment: 34 pages, 15 figures, Nucl.Phys. A, in pres