Two-Dimensional Spectral Interferometry using the Carrier-Envelope Phase

Two- and multi-dimensional spectroscopy is used in physics and chemistry to obtain structural and dynamical information that would otherwise be invisible by the projection into a one-dimensional data set such as a single emission or absorption spectrum. Here, we introduce a qualitatively new two-dimensional spectroscopy method by employing the carrier-envelope phase (CEP). Instead of measuring spectral vs. spectral information, the combined application of spectral interferometry and CEP control allows the measurement of otherwise inseparable temporal events on an attosecond time scale. As a specific example, we apply this general method to the case of attosecond pulse train generation, where it allows to separate contributions of three different sub-cycle electron quantum paths within one and the same laser pulse, resulting in a better physical understanding and quantification of the transition region between cutoff and plateau harmonics. The CEP-dependent separation in time between two full-cycle spaced attosecond pulses was determined to modulate by (54 +/- 16) attoseconds

A Model of Vertical Oligopolistic Competition

This paper develops a model of successive oligopolies with endogenous market entry, allowing for varying degrees of product differentiation and entry costs in both markets. Our analysis shows that the downstream conditions dominate the overall profitability of the two-tier structure while the upstream conditions mainly affect the distribution of profits. We compare the welfare effects of upstream versus downstream deregulation policies and show that the impact of deregulation may be overvalued when ignoring feedback effects from the other market. Furthermore, we analyze how different forms of vertical restraints influence the endogenous market structure and show when they are welfare enhancing

Paramedics' Newborn Life Support Knowledge and Skills Before and After a Targeted Simulation-Based Educational Intervention

Objective: Resuscitation of neonates after birth in the out-of-hospital setting is challenging. Thus, we aimed to assess paramedics' newborn life support knowledge and skills before and after targeted simulation-based training.Methods: Voluntary paramedics were recruited from a single Red Cross division. During a 1-day simulation-based educational intervention, essential aspects of neonatal resuscitation were taught and practiced. Before and after simulation-based training, we assessed (1) knowledge of current European Resuscitation Council (ERC) guidelines using a 20-item-questionnaire and (2) the quality of simulated bag-valve-mask ventilation by measuring face mask leakage, using a respiratory function monitor (Standardized Measurement of Airway Resuscitation Training [SMART], GM Instruments Ltd., United Kingdom).Results: Forty-one paramedics participated in the initial survey and 12 took part in the simulation-based educational intervention. There was a significant increase in the number of correctly answered questions: median 62.1% (IQR 37.5–77.4%) vs. 91.7% (IQR 83.3–100%; p = 0.001). A total of 1,332 inflations were analyzed. The incidence of substantial mask leakage >75% decreased significantly after training (15.8 vs. 6.1%; p < 0.001), while median mask leakage was similar (17.0% [IQR 0.0–55.0%] vs. 18.0% [IQR 6.0–34.0%]; p = 0.414).Conclusions: Among paramedics, theoretical knowledge of current ERC guidelines was moderate in this study. Participation in a targeted simulation-based educational intervention was associated with a significant increase in theoretical knowledge. The initially high incidence of substantial mask leakage >75% was decreased after simulation-based training using respiratory function monitoring

Tailoring the FeO/SiO2 ratio in electric arc furnace slags to minimize the leaching of vanadium and chromium

Based on recently published research on leaching control mechanisms in electric arc furnace (EAF) slags, it is assumed that a FeO/SiO2 ratio of around one leads to low leached V and Cr concentrations. This ratio influences the mineral phase composition of the slag toward higher amounts of spinel and a lower solubility of calcium silicate phases by suppressing the formation of magnesiowuestite and highly soluble calcium silicate phases. To evaluate this hypothesis, laboratory and scaled up tests in an EAF pilot plant were performed on slag samples characterized by elevated V and Cr leaching and a high FeO/SiO2 ratio. Prior to the melting experiments, the optimum FeO/SiO2 ratio was calculated via FactSageTM. In the melting experiments, the ratio was adjusted by adding quartz sand, which also decreased the basicity (CaO/SiO2) of the slag. As a reference, remelting experiments without quartz sand addition were conducted and additionally, the influence of the cooling rate of the slag was examined. The remelted (without quartz sand) and the remelted modified slags (with quartz sand) were analyzed chemically and mineralogically and the leaching behavior was investigated. The modification of the slags yielded a minimized release of V and Cr, supporting the hypothesis that the FeO/SiO2 ratio influences the mineralogy and the leaching behavior

Germline mutations in the oncogene EZH2 cause Weaver syndrome and increased human height.

The biological processes controlling human growth are diverse, complex and poorly understood. Genetic factors are important and human height has been shown to be a highly polygenic trait to which common and rare genetic variation contributes. Weaver syndrome is a human overgrowth condition characterised by tall stature, dysmorphic facial features, learning disability and variable additional features. We performed exome sequencing in four individuals with Weaver syndrome, identifying a mutation in the histone methyltransferase, EZH2, in each case. Sequencing of EZH2 in additional individuals with overgrowth identified a further 15 mutations. The EZH2 mutation spectrum in Weaver syndrome shows considerable overlap with the inactivating somatic EZH2 mutations recently reported in myeloid malignancies. Our data establish EZH2 mutations as the cause of Weaver syndrome and provide further links between histone modifications and regulation of human growth

The possible existence of Hs in nature from a geochemical point of view

A hypothesis of the existence of a long-lived isotope 271Hs in natural molybdenites and osmirides is considered from a geochemical point of view. It is shown that the presence of Hs in these minerals can be explained only by making an additional ad hoc assumption on the existence of an isobaric pair of 271Bh-271Hs. This assumption could be tested by mass-spectrometric measurements of U, Pb, Kr, Xe, and Zr isotopic shifts.Comment: 5 pages, no figures. Physics of Particles and Nuclei Letters, 2006, Vol. 3, No. 3, pp. 165-168 in pres

Characterization and Tuning of Ultra High Gradient Permanent Magnet Quadrupoles

The application of quadrupole-devices with high field gradients and small apertures requires precise control over higher order multipole field components. We present a new scheme for performance control and tuning, which allows the illumination of most of the quadrupole-device aperture because of the reduction of higher order field components. Consequently, the size of the aperture can be minimized to match the beam size achieving field gradients of up to 500 T/m at good imaging quality. The characterization method based on a Hall probe measurement and a Fourier analysis was confirmed using the high quality electron beam at the Mainz Microtron MAMI

Strong-field spectral interferometry using the carrier–envelope phase

Abstract The carrier–envelope phase (CEP) of ultrashort laser pulses is an important parameter in strong-field physics that controls temporally localized events on a sub-cycle timescale. The relative timing of these events is directly encoded into the measured spectral intensity distribution, and can be accessed by the use of spectral interferometry. Here, we combine this analysis with CEP control in a two-dimensional way, creating a novel spectroscopic method to explore the temporal dynamics of strong-field processes. We apply this general method to CEP-dependent high-harmonic generation and find that contributions of three different sub-cycle electron quantum paths can be separated, allowing one to quantify the dipole-phase dependence on the CEP in the non-adiabatic regime. The CEP-dependent time delay between two full-cycle spaced attosecond pulses was determined to modulate by 54 ± 16 as. We confirm the generality of the method by further applying it to CEP-dependent photoemission from a nanoscale metal tip