Comment on "On the Origin of the Highest Energy Cosmic Rays"

We show that the photodisintegration of heavy cosmic ray nuclei with energies above 10^20 eV is dominated by interactions with photons from the cosmic microwave background radiation, rather than from infrared ones. This implies that the observed air shower events with energies 2-3 10^20 eV cannot originate from Fe nuclei coming from distances beyond 10 MpcComment: 1 page, 2 figure

Insights on neutrino lensing

We discuss the gravitational lensing of neutrinos by astrophysical objects. Unlike photons, neutrinos can cross a stellar core; as a result, the lens quality improves. We also estimate the depletion of the neutrino flux after crossing a massive object and the signal amplification expected. While Uranians alone would benefit from this effect in the Sun, similar effects could be considered for binary systems.Comment: 15 pages, 4 figures, to be published in Phys. Lett.

Estimates of multipolar coefficients to search for cosmic ray anisotropies with non-uniform or partial sky coverage

We study the possibility to extract the multipolar moments of an underlying distribution from a set of cosmic rays observed with non-uniform or even partial sky coverage. We show that if the degree is assumed to be upper bounded by $L$, each multipolar moment can be recovered whatever the coverage, but with a variance increasing exponentially with the bound $L$ if the coverage is zero somewhere. Despite this limitation, we show the possibility to test predictions of a model without any assumption on $L$ by building an estimate of the covariance matrix seen through the exposure function.Comment: 20 pages, 8 figure

Quantitative Margin Analysis in the Scanning Electron Microscope.

Interface between restorative materials and tooth hard substances must be morphologically as perfect as possible to avoid plaque accumulation and subsequent secondary caries or pulpal diseases. Therefore the marginal behavior of restorations is an important parameter to predict their longevity. Morphologically, the quality of margins is characterized by different well defined criteria. Using a replica technique it is possible to assess the complete marginal circumference of restorations in the SEM. Margins of restorations show a large variety of their morphology. This publication describes a method to quantify the quality of dental restorations. The restoration margins are traced on the SEM screen with a digitizer and an interface to measure the margin\u27s length. Simultaneously the margin quality is assessed and assigned to the corresponding lengths. The % distribution of the quality criteria for each restoration is then calculated. Using a comparative light microscope, the replicas are aligned and mounted identically in the SEM for longitudinal studies. The results presented are limited to tests for the accuracy of the method. Using 5 criteria to characterize the margin quality, it was found that the difference between two measurements by the same operator, 4 weeks apart was 3% ± 2.6%. The largest difference for one group was 9%. In another accuracy test where 4 criteria for margin characterization were used, the difference between two measurements was 1.9% ± 0.9%. The largest difference between two groups found was 3.4%. This method can be used for longitudinal studies in vivo, but also for in vitro screening tests with new materials

Laser annealing of silicon on sapphire

Silicon-implanted silicon-on-sapphire wafers have been annealed by 50-ns pulses from a Q-switched Nd : YAG laser. The samples have been analyzed by channeling and by omega-scan x-ray double diffraction. After irradiation with pulses of a fluence of about 5 J cm^–2 the crystalline quality of the silicon layer is found to be better than in the as-grown state

Pediatric stroke related to Lyme neuroborreliosis: Data from the Swiss NeuroPaediatric Stroke Registry and literature review.

Cerebrovascular complications of Lyme neuroborreliosis (LNB) are poorly documented in the paediatric population. We performed a retrospective analysis from prospectively registered cases of acute ischemic stroke (AIS) from the Swiss NeuroPaediatric Stroke Registry (SNPSR) from 2000 to 2015. Only cases with serologically confirmed LNB were included. In addition, a literature review on paediatric stroke cases secondary to Lyme neuroborreliosis in the same time frame was performed. 4 children out of 229 children with arterial ischemic childhood stroke and serologically confirmed LNB were identified in the SNPSR giving a global incidence of 1.7%. Median age was 9.9 years. A prior history of tick bites or erythema migrans (EM) was reported in two cases. Clinical presenting signs were suggestive of acute cerebellar/brainstem dysfunction. On imaging, three children demonstrated a stroke in the distribution of the posterior inferior cerebellar artery. The remaining fourth child had a "stroke-like" picture with scattered white matter lesions and a multifocal vasculitis with prominent basilar artery involvement. Lymphocytic pleocytosis as well as intrathecal synthesis of Borrelia burgdorferi antibodies were typical biological features. Acute intravenous third generation cephalosporins proved to be effective with rapid improvement in all patients. No child had recurrent stroke. Data from the literature concerning eight patients gave similar results, with prominent posterior circulation stroke, multifocal vasculitis and abnormal CSF as distinctive features. Lyme Neuroborreliosis accounts for a small proportion of paediatric stroke even in an endemic country. The strong predilection towards posterior cerebral circulation with clinical occurrence of brainstem signs associated with meningeal symptoms and CSF lymphocytosis are suggestive features that should rapidly point to the diagnosis. This can be confirmed by appropriate serological testing in the serum and CSF. Clinicians must be aware of this rare neurological complication of Lyme disease that demands specific antibiotic treatment

Suppression of \bbox{T_c} in superconducting amorphous wires

The suppression of the mean field temperature of the superconducting transition, $T_c$, in homogeneous amorphous wires is studied. We develop a theory that gives $T_c$ in situations when the dynamically enhanced Coulomb repulsion competes with the contact attraction. The theory accurately describes recent experiments on $T_c$--suppression in superconducting wires, after a procedure that minimizes the role of nonuniversal mechanisms influencing $T_c$ is applied.Comment: RevTeX, 4 pages, 3 figure

HIGH SPIN ISOMERIC STATES IN 197Pb

High spin isomeric states in 197Pb have been investigated by in-beam gamma ray technics. These states are produced in (heavy ion, xn) reactions. various experiments performed are summarized in table I

`Natural Masslessness Conservation' for neutrinos in two Higgs-doublet models

We present a model which supplements the Standard Electroweak Model with three right-handed neutrinos and one extra scalar doublet which does not develop a vacuum expectation value. With the aid of a discrete symmetry the neutrinos are kept strictly massless. This model has several interesting features. It has unsuppressed lepton flavour violating processes, in particular $\mu \rightarrow e \gamma$, hinting at the possibility that these may soon be within experimental reach. The $Z$ and $W$ interactions become non-diagonal at one loop level. In particular, a non-trivial leptonic mixing matrix is seen to arise from the clash between the charged gauge boson and the charged scalar interactions.Comment: (Latex file, 12 pages. Two figures available upon request). CMU-preprin