Effects of electron-phonon interactions on the electron tunneling spectrum of PbS quantum dots

We present a tunnel spectroscopy study of single PbS Quantum Dots (QDs) as function of temperature and gate voltage. Three distinct signatures of strong electron-phonon coupling are observed in the Electron Tunneling Spectrum (ETS) of these QDs. In the shell-filling regime, the $8\times$ degeneracy of the electronic levels is lifted by the Coulomb interactions and allows the observation of phonon sub-bands that result from the emission of optical phonons. At low bias, a gap is observed in the ETS that cannot be closed with the gate voltage, which is a distinguishing feature of the Franck-Condon (FC) blockade. From the data, a Huang-Rhys factor in the range $S\sim 1.7 - 2.5$ is obtained. Finally, in the shell tunneling regime, the optical phonons appear in the inelastic ETS $d^2I/dV^2$.Comment: 5 pages, 5 figure

Is there something of the MCT in orientationally disordered crystals ?

Molecular Dynamics simulations have been performed on the orientationally disordered crystal chloroadamantane: a model system where dynamics are almost completely controlled by rotations. A critical temperature T_c = 225 K as predicted by the Mode Coupling Theory can be clearly determined both in the alpha and beta dynamical regimes. This investigation also shows the existence of a second remarkable dynamical crossover at the temperature T_x > T_c consistent with a previous NMR and MD study [1]. This allows us to confirm clearly the existence of a 'landscape-influenced' regime occurring in the temperature range [T_c-T_x] as recently proposed [2,3].Comment: 4 pages, 5 figures, REVTEX

A low density of 0.8 g/cc for the Trojan binary asteroid 617 Patroclus

The Trojan population consists of two swarms of asteroids following the same orbit as Jupiter and located at the L4 and L5 Lagrange points of the Jupiter-Sun system (leading and following Jupiter by 60 degrees). The asteroid 617 Patroclus is the only known binary Trojan (Merline et al. 2001). The orbit of this double system was hitherto unknown. Here we report that the components, separated by 680 km, move around the system centre of mass, describing roughly a circular orbit. Using the orbital parameters, combined with thermal measurements to estimate the size of the components, we derive a very low density of 0.8 g/cc. The components of Patroclus are therefore very porous or composed mostly of water ice, suggesting that they could have been formed in the outer part of the solar system.Comment: 10 pages, 3 figures, 1 tabl

A mathematical model to predict mean time to delivery following cervical ripening with dinoprostone vaginal insert

The main objective of our study was to analyze the mean time to delivery following cervical ripening with a 10 mg dinoprostone vaginal insert. We performed a retrospective observational study at the level III maternity ward of Angers university hospital. We included all women who had cervical ripening with dinoprostone between January 1, 2015 and September 30, 2016. Overall, 405 patients were included, and 59.3% (240/405) were nulliparous. The mean time to delivery was 20h39 min ± 10h49 min. 21% of deliveries (86/405) occurred between midnight and 6 h a.m., and the cesarean section rate was 33% (132/405). Multiple regression analysis showed that nulliparity, overweight (BMI ≥ 25), a closed cervix on initial examination and the absence of premature rupture of membranes (PRM) all significantly increased the mean time to delivery. We developed a mathematical model integrating the aforementioned factors and their impact to help predict the mean time to delivery following cervical ripening with dinoprostone vaginal insert: Y = 961.188-80.346 × parity + 21.437 × BMI-165.263 × cervical dilation-241.759 × PRM. This equation allows obstetricians to calculate a personalized time to delivery for each patient, allowing a precise scheduling of dinoprostone insert placement, and thus improving the organization in busy maternity wards

Culture of per-wound bone specimens: a simplified approach for the medical management of diabetic foot osteomyelitis

AbstractSurgical percutaneous bone biopsy specimen after a 14-day antibiotic-free period represents the gold standard of care for diabetic foot osteomyelitis but may be difficult to implement in many institutions. We evaluate a simplified strategy based on the results of per-wound bone specimen culture. For that purpose, we retrospectively reviewed the charts of 80 consecutive patients with diabetic osteomyelitis and bone sample obtained via the wound after a careful debridement. The outcome was defined as favourable if there was a complete healing of the wound with no sign of infection and stable or improved bone X-ray 6 months after antibiotic therapy completion. Culture of bone specimens was positive in 96% of patients, although half of the patients did receive a course of antimicrobials within 14 days of the bone specimen being obtained. A total of 129 bacterial isolates were obtained from bone cultures with a mean of 1.6 ± 1 isolates per patient (Staphylococcus aureus: 33%; coagulase-negative staphylococci: 14%; streptococci: 9%; enterococci: 12%; corynebacteria: 4%; Gram-negative bacilli: 20%; anaerobes: 4%). Forty-six percent of cultures were monomicrobial. The mean duration of follow-up from diagnosis was 17 ± 1 months. Six months after discontinuation of antibiotics, six patients (7.5%) had died, nine were considered as therapeutic failures and 65 were considered as cured. Fifty-four of these 65 patients had follow-up data available at 1 year and remained in remission. In conclusion, a simplified procedure based on the culture of bone sample obtained via the ulcer after a careful debridement of the wound is effective in the medical management of diabetic foot osteomyelitis

Triplicity and Physical Characteristics of Asteroid (216) Kleopatra

To take full advantage of the September 2008 opposition passage of the M-type asteroid (216) Kleopatra, we have used near-infrared adaptive optics (AO) imaging with the W.M. Keck II telescope to capture unprecedented high resolution images of this unusual asteroid. Our AO observations with the W.M. Keck II telescope, combined with Spitzer/IRS spectroscopic observations and past stellar occultations, confirm the value of its IRAS radiometric radius of 67.5 km as well as its dog-bone shape suggested by earlier radar observations. Our Keck AO observations revealed the presence of two small satellites in orbit about Kleopatra (see Marchis et al., 2008). Accurate measurements of the satellite orbits over a full month enabled us to determine the total mass of the system to be 4.64+/-0.02 10^18 Kg. This translates into a bulk density of 3.6 +/-0.4 g/cm3, which implies a macroscopic porosity for Kleopatra of ~ 30-50%, typical of a rubble-pile asteroid. From these physical characteristics we measured its specific angular momentum, very close to that of a spinning equilibrium dumbbell.Comment: 35 pages, 3 Tables, 9 Figures. In press to Icaru

Avian cholera, a threat to the viability of an Arctic seabird colony?

© The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in PLoS One 7 (2012): e29659, doi:10.1371/journal.pone.0029659.Evidence that infectious diseases cause wildlife population extirpation or extinction remains anecdotal and it is unclear whether the impacts of a pathogen at the individual level can scale up to population level so drastically. Here, we quantify the response of a Common eider colony to emerging epidemics of avian cholera, one of the most important infectious diseases affecting wild waterfowl. We show that avian cholera has the potential to drive colony extinction, even over a very short period. Extinction depends on disease severity (the impact of the disease on adult female survival) and disease frequency (the number of annual epidemics per decade). In case of epidemics of high severity (i.e., causing >30% mortality of breeding females), more than one outbreak per decade will be unsustainable for the colony and will likely lead to extinction within the next century; more than four outbreaks per decade will drive extinction to within 20 years. Such severity and frequency of avian cholera are already observed, and avian cholera might thus represent a significant threat to viability of breeding populations. However, this will depend on the mechanisms underlying avian cholera transmission, maintenance, and spread, which are currently only poorly known.The study was supported by the Canadian Wildlife Service-Environment Canada (http://www.ec.gc.ca/), Nunavut Wildlife Management Board (http:// www.nwmb.com/), Greenland Institute of Natural Resources (http://www.natur.gl/), Polar Continental Shelf Project (http://polar.nrcan.gc.ca/), Fonds Que´be´cois de la Recherche sur la Nature et les Technologies (http://www.fqrnt.gouv.qc.ca/), Canadian Network of Centres of Excellence ArcticNet (http://www.arcticnet.ulaval. ca/), Natural Sciences and Engineering Research Council of Canada (http://www.nserc-crsng.gc.ca/), and the Department of Indian Affairs and Northern Canada (http://www.ainc-inac.gc.ca/)

Optimizing Anti-Inflammatory and Immunomodulatory Effects of Corticosteroid and Vitamin D Analogue Fixed-Dose Combination Therapy

Abstract: Fixed-dose combination topical therapy with corticosteroid and vitamin D analog provides effective treatment and possible long-term management of psoriasis. The anti-inflammatory and immunomodulatory effects of corticosteroids and vitamin D analogs in treating psoriasis are well investigated; their complementary effects lead to the disruption of the inflammatory feedback loop underlying psoriasis pathogenesis. Recent preclinical data showed that combination therapy is more effective than monotherapies of the active ingredients in preventing activation of resting pro-inflammatory cells, inducing immunomodulation, reducing inflammatory responses by regulating T cell production, and normalizing keratinocytes. The increased understanding of the mechanism of action of fixed-dose combination therapy from preclinical studies is supported by several clinical studies. As the efficacy of topical therapy is correlated with the skin penetration of the active ingredients, new drug delivery systems have been developed. The fixed-dose combination Cal/BD aerosol foam creates a modified supersaturated formulation when applied to the skin, which is maintained for at least 26 h in the laboratory setting. Clinical studies have demonstrated superior efficacy of fixed-dose combination calcipotriol (Cal) 50 µg/g and betamethasone dipropionate (BD) 0.5 mg/g aerosol foam compared with monotherapies of the active ingredients. Furthermore, Cal/BD aerosol foam has shown significantly improved efficacy compared with more traditional formulations, such as Cal/BD ointment and gel, in other studies. Calcipotriol also mitigates risks associated with betamethasone dipropionate and vice versa, resulting in the favorable safety profile observed with fixed-dose combination treatment. Recent data also suggest that fixed-dose combination treatment could provide long-term management of psoriasis, although further clinical investigations are needed. Overall, these data support the value of fixed-dose combination therapy of corticosteroid and vitamin D analog and highlight the added potential of innovative drug delivery for the treatment of psoriasis. Funding: LEO Pharma

Extreme ultraviolet interferometry measurements with high-order harmonics

We demonstrate that high-order harmonics generated by short, intense laser pulses in gases provide an interesting radiation source for extreme ultraviolet interferometry, since they are tunable, coherent, of short pulse duration, and simple to manipulate. Harmonics from the 9th to the 15th are used to measure the thickness of an aluminum layer. The 11th harmonic is used to determine the spatial distribution of the electron density of a plasma produced by a 300-ps laser. Electronic densities higher than 2-10(20) electrons/cm(3) are measured. (C) 2000 Optical Society of America. OCIS codes: 190.0190, 190.4160, 190.7110, 120.3180, 140.7240, 350.4500