1,560 research outputs found
Synchronously-pumped OPO coherent Ising machine: benchmarking and prospects
The coherent Ising machine (CIM) is a network of optical parametric oscillators (OPOs) that solves for the ground state of Ising problems through OPO bifurcation dynamics. Here, we present experimental results comparing the performance of the CIM to quantum annealers (QAs) on two classes of NP-hard optimization problems: ground state calculation of the Sherrington-Kirkpatrick (SK) model and MAX-CUT. While the two machines perform comparably on sparsely-connected problems such as cubic MAX-CUT, on problems with dense connectivity, the QA shows an exponential performance penalty relative to CIMs. We attribute this to the embedding overhead required to map dense problems onto the sparse hardware architecture of the QA, a problem that can be overcome in photonic architectures such as the CIM
Edge channel mixing induced by potential steps in an integer quantum Hall system
We investigate the coherent mixing of co-propagating edge channels in a
quantum Hall bar produced by step potentials. In the case of two edge channels
it is found that, although a single step induces only a few percent mixing, a
series of steps could yield 50% mixing. In addition, a strong mixing is found
when the potential height of a single step allows a different number of edge
channels on the two sides of the step. Charge density probability has been also
calculated even for the case where the step is smoothened.Comment: final version: 7 pages, 6 figure
Combined numerical approach for the evaluation of the energy efficiency and economic investment of building external insulation technologies
Action minimizing orbits in the n-body problem with simple choreography constraint
In 1999 Chenciner and Montgomery found a remarkably simple choreographic
motion for the planar 3-body problem (see \cite{CM}). In this solution 3 equal
masses travel on a eight shaped planar curve; this orbit is obtained minimizing
the action integral on the set of simple planar choreographies with some
special symmetry constraints. In this work our aim is to study the problem of
masses moving in \RR^d under an attractive force generated by a potential
of the kind , , with the only constraint to be a simple
choreography: if are the orbits then we impose the
existence of x \in H^1_{2 \pi}(\RR,\RR^d) such that q_i(t)=x(t+(i-1) \tau),
i=1,...,n, t \in \RR, where . In this setting, we first
prove that for every d,n \in \NN and , the lagrangian action
attains its absolute minimum on the planar circle. Next we deal with the
problem in a rotating frame and we show a reacher phenomenology: indeed while
for some values of the angular velocity minimizers are still circles, for
others the minima of the action are not anymore rigid motions.Comment: 24 pages; 4 figures; submitted to Nonlinearit
Adjunctive therapy with vitamin c and thiamine in patients treated with steroids for refractory septic shock: A propensity matched before-after, case-control study
Purpose: Triple therapy with steroids, vitamin C and thiamine has been recently proposed as a safe and beneficial in patients with sepsis. In 2017, we added the use of intravenous vitamin C and thiamine in septic shock patients receiving low dose hydrocortisone because poorly responsive to vasopressors. Aim of this study is to verify whether triple therapy rather than steroids alone can improve outcome in patients with refractory shock. Materials and methods: In this before-after retrospective analysis, we compared septic shock patients admitted to our intensive care unit (ICU) who received triple therapy from June 2017 to November 2019 to septic shock patients who received only hydrocortisone from January 2015 to June 2017. Patients of the two study periods were matched 1:1 using a propensity score model. Results: A final cohort of 56 patients treated with triple therapy were matched to 56 patients treated only with steroids. Triple therapy reduced the length of mechanical ventilation (p = 0,01) and showed a trend in lowering the 30-day and hospital mortality compared to therapy with only hydrocortisone. Conclusions: Although with significant limitations, our experience indicated that triple therapy seems to provide an improvement of clinical outcomes in patients with refractory septic shock
How Does Financial Market Evaluate Business Models? Evidence From European Banks
This paper investigates the way in which the financial market defines and evaluates different business models/business mix, using a sample of listed European banking groups, with a total asset value greater than 50 billion US$, for the period 2006-2015. The main results suggest that non-interest components foster market valuation and that financial market seems to associate a better risk-return trade-off to non-banking fees compared to the banking ones. This evidence enables us to identify 3 clusters of European banking groups based on the main components of income. These findings have strategic implications both for bank managers, regulators and supervisors due to the impact of the crisis on banking business, bank profitability and riskiness and the new challenges they entail
Oral health and depressive symptoms: findings from the English Longitudinal Study of Ageing
Aim We assessed the cross-sectional association between depressive symptoms and oral health using a nationally representative sample of older adults aged 50 years and older living in England.Methods Data came from wave 7 (2014-2015) of the English Longitudinal Study of Ageing. Multiple logistic regression analyses were conducted to assess the association between depressive symptoms, measured through the eight-item Centre for Epidemiologic Studies Depression Scale and three oral health outcomes, namely self-rated oral health, edentulousness and oral impacts.Results The analytical sample comprised 3,617 individuals. The proportion of participants that reported poor self-rated oral health, being edentate and having at least one oral health impact in the last six months was 19.8%, 7.7% and 8.9%, respectively. Around a tenth of the participants reported having depressive symptoms (10%). All unadjusted associations between depressive symptoms and the oral health measures were statistically significant. However, after accounting for potential confounders, only the relationship between depressive symptoms and self-rated oral health remained significant (OR = 1.38; 95% CI 1.01-1.89). Socioeconomic and general health-related variables appeared to influence the associations between depressive symptoms and oral health, particularly edentulousness and oral impacts.Conclusion Depressive symptoms were associated with poor self-rated oral health in older English adults
Experimental evidence of antiproton reflection by a solid surface
We report here experimental evidence of the reflection of a large fraction of
a beam of low energy antiprotons by an aluminum wall. This derives from the
analysis of a set of annihilations of antiprotons that come to rest in rarefied
helium gas after hitting the end wall of the apparatus. A Monte Carlo
simulation of the antiproton path in aluminum indicates that the observed
reflection occurs primarily via a multiple Rutherford-style scattering on Al
nuclei, at least in the energy range 1-10 keV where the phenomenon is most
visible in the analyzed data. These results contradict the common belief
according to which the interactions between matter and antimatter are dominated
by the reciprocally destructive phenomenon of annihilation.Comment: 5 pages with 5 figure
Crystal Structure Studies of Human Dental Apatite as a Function of Age
Studies of the average crystal structure properties of human dental apatite
as a function of the tooth-age in the range of 5-87 years are reported. The
crystallinity of the dental hydroxyapatite decreases with the tooth-age. The
a-lattice constant that is associated with the carbonate content in carbonate
apatite decreases with the tooth-age in a systematic way, whereas the c-lattice
constant does not change significantly. Thermogravimetric measurements
demonstrate an increase of the carbonate content with the tooth-age. FTIR
spectroscopy reveals both, B and A-type carbonate substitutions with the B-type
greater than the A-type substitution by a factor up to ~5. An increase of the
carbonate content as a function of the tooth-age can be deduced from the ratio
of the v2 CO3 to the v1 PO4 IR modes.Comment: 17 page
Yeast Nanometric Scale Oscillations Highlights Fibronectin Induced Changes in C. albicans
Yeast resistance to antifungal drugs is a major public health issue. Fungal adhesion onto the host mucosal surface is still a partially unknown phenomenon that is modulated by several actors among which fibronectin plays an important role. Targeting the yeast adhesion onto the mucosal surface could lead to potentially highly efficient treatments. In this work, we explored the effect of fibronectin on the nanomotion pattern of different Candida albicans strains by atomic force microscopy (AFM)-based nanomotion detection and correlated the cellular oscillations to the yeast adhesion onto epithelial cells. Preliminary results demonstrate that strongly adhering strains reduce their nanomotion activity upon fibronectin exposure whereas low adhering Candida remain unaffected. These results open novel avenues to explore cellular reactions upon exposure to stimulating agents and possibly to monitor in a rapid and simple manner adhesive properties of C. albicans
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