28,878 research outputs found
A digital system for accurate time sector division of a spin stabilized vehicle
Digital system for accurate time sector division of spin stabilized vehicle as used on Pioneer space probe
Arbuscular mycorrhizal fungal hyphae reduce soil erosion by surface water flow in a greenhouse experiment
This research was funded by the SMART Joint Doctoral Programme (Erasmus Mundus Programme of the European Union) and the DRS HONORS Fellowship programme of Freie Universität Berlin. This study is a contribution to an EU Marie Curie Career Integration Grant to T.C. (EC FP7-631399-SENSE
Cosmic ray tables - Asymptotic directions, variational coefficients and cut-off rigidities IQSY instruction manual no. 10
Cosmic ray deflections in geomagnetic field, variational coefficients, and diurnal intensity variations - table
Early use of abiraterone and radium-223 in metastatic prostate cancer
[No abstract available
Effects of ocean acidification on invertebrate settlement at volcanic CO<inf>2</inf> vents
We present the first study of the effects of ocean acidification on settlement of benthic invertebrates and microfauna. Artificial collectors were placed for 1 month along pH gradients at CO2 vents off Ischia (Tyrrhenian Sea, Italy). Seventy-nine taxa were identified from six main taxonomic groups (foraminiferans, nematodes, polychaetes, molluscs, crustaceans and chaetognaths). Calcareous foraminiferans, serpulid polychaetes, gastropods and bivalves showed highly significant reductions in recruitment to the collectors as pCO2 rose from normal (336-341 ppm, pH 8.09-8.15) to high levels (886-5,148 ppm) causing acidified conditions near the vents (pH 7.08-7.79). Only the syllid polychaete Syllis prolifera had higher abundances at the most acidified station, although a wide range of polychaetes and small crustaceans was able to settle and survive under these conditions. A few taxa (Amphiglena mediterranea, Leptochelia dubia, Caprella acanthifera) were particularly abundant at stations acidified by intermediate amounts of CO2 (pH 7. 41-7.99). These results show that increased levels of CO2 can profoundly affect the settlement of a wide range of benthic organisms. © 2010 Springer-Verlag
Stationary Kolmogorov Solutions of the Smoluchowski Aggregation Equation with a Source Term
In this paper we show how the method of Zakharov transformations may be used
to analyze the stationary solutions of the Smoluchowski aggregation equation
for arbitrary homogeneous kernel. The resulting massdistributions are of
Kolmogorov type in the sense that they carry a constant flux of mass from small
masses to large. We derive a ``locality criterion'', expressed in terms of the
asymptotic properties of the kernel, that must be satisfied in order for the
Kolmogorov spectrum to be an admissiblesolution. Whether a given kernel leads
to a gelation transition or not can be determined by computing the mass
capacity of the Kolmogorov spectrum. As an example, we compute the exact
stationary state for the family of
kernels, which includes both gelling and
non-gelling cases, reproducing the known solution in the case .
Surprisingly, the Kolmogorov constant is the same for all kernels in this
family.Comment: This article is an expanded version of a talk given at IHP workshop
"Dynamics, Growth and Singularities of Continuous Media", Paris July 2003.
Updated 01/04/04. Revised version with additional discussion, references
added, several typographical errors corrected. Revised version accepted for
publication by Phys. Rev.
Banal nationalism and the imagining of politics
Banal nationalism and the imagining of politic
Ray and wave chaos in asymmetric resonant optical cavities
Optical resonators are essential components of lasers and other
wavelength-sensitive optical devices. A resonator is characterized by a set of
modes, each with a resonant frequency omega and resonance width Delta
omega=1/tau, where tau is the lifetime of a photon in the mode. In a
cylindrical or spherical dielectric resonator, extremely long-lived resonances
are due to `whispering gallery' modes in which light circulates around the
perimeter trapped by total internal reflection. These resonators emit light
isotropically. Recently, a new category of asymmetric resonant cavities (ARCs)
has been proposed in which substantial shape deformation leads to partially
chaotic ray dynamics. This has been predicted to give rise to a universal,
frequency-independent broadening of the whispering-gallery resonances, and
highly anisotropic emission. Here we present solutions of the wave equation for
ARCs which confirm many aspects of the earlier ray-optics model, but also
reveal interesting frequency-dependent effects characteristic of quantum chaos.
For small deformations the lifetime is controlled by evanescent leakage, the
optical analogue of quantum tunneling. We find that the lifetime is much
shortened by a process known as `chaos-assisted tunneling'. In contrast, for
large deformations (~10%) some resonances are found to have longer lifetimes
than predicted by the ray chaos model due to `dynamical localization'.Comment: 4 pages RevTeX with 7 Postscript figure
Children at risk of domestic accidents when are locked up at home: the other side of COVID-19 outbreak lockdown
Background We proposed to analyze thoroughly the impact of the COVID-19 lockdown (CL) in changes of profiles and in trend of the domestic accidents (DAs) in children. Methods This was a single experience, cross-sectional study conducted at the emergency department (ED) of III trauma center. We enrolled children under 18 years admitted to ED with a diagnosis of DAs comparing the CL period from 10(th) March 2020 to 4(th) May 2020 with the same period of the previous year,10(th) March 2019 to 4(th) May 2019. Results In CL period, the cumulative incidence of ED visits for DAs increased from 86.88 to 272.13 per 1,000 children and the cumulative incidence of hospitalizations for DAs increased from 409.72 to 534.48 per 1,000 children. We reported in CL a decrease in the severity of ED presentation assessed by proxy measures: the level of priority ED visits reduced by 67% in CL period (OR: 0.33; 95%CI 0.22-0.48; p < 0.001); the likelihood of delayed time of presentation to ED increased by 65% in case of domestic injuries occurring in CL period (OR: 1.65; 95% CI: 1.17-2.34; p = 0.004); the odds of transfer from other hospital decreased by 78% in CL (OR: 0.15-0.33; p < 0.001). Children were more at risk of poisoning (OR:3.35-106.11; p = 0.001), of body foreign ingestion (OR: 1.83-14.39; p = 0.002) and less at risk of animal bite trauma (OR:0.05-0.35; p < 0.001). Conclusion Although the need to stay home has made a decisive breakthrough on the spread of COVID-19, the experience from this study underlines how this preventive measure has also had a downside in term of increased cumulative incidence of ED visits and of hospitalizations for DA
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