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In language switching, it is assumed that in order to produce a response in one language, the other language must be inhibited. In unimodal (spoken-spoken) language switching, the fact that the languages share the same primary output channel (the mouth) means that only one language can be produced at a time. In bimodal (spoken-signed) language switching, however, it is possible to produce both languages simultaneously. In our study, we examined modality effects in language switching using multilingual subjects (speaking German, English, and German Sign Language). Focusing on German vocal responses, since they are directly compatible across conditions, we found shorter reaction times, lower error rates, and smaller switch costs in bimodal vs. unimodal switching. This result suggests that there are different inhibitory mechanisms at work in unimodal and bimodal language switching. We propose that lexical inhibition is involved in unimodal switching, whereas output channel inhibition is involved in bimodal switching.
We have used dedicated 0.7m telescopes in California and Israel to image the halos of ~ 200 galaxies in the Local Volume to 29 mag/sq arcsec, the sample mainly drawn from the 2MASS Large Galaxy Atlas (LGA). We supplement the LGA sample with dwarf galaxies and more distant giant ellipticals. Low surface brightness halos exceeding 50 kpc in diameter are found only in galaxies more luminous than L*, and classic interaction signatures are relatively infrequent. Halo diameter is correlated with total galaxy luminosity. Extended low surface brightness halos are present even in galaxies as faint as MV = - 18. Edge-on galaxies with boxy bulges tend to lack extended spheroidal halos, while those with large classical bulges exhibit extended round halos, supporting the notions that boxy or barlike bulges originate from disks. Most face-on spiral galaxies present features that appear to be irregular extensions of spiral arms, although rare cases show smooth boundaries with no sign of star formation. Although we serendipitously discovered a dwarf galaxy undergoing tidal disruption in the halo of NGC 4449, we found no comparable examples in our general survey. A search for similar examples in the Local Volume identified hcc087, a tidally disrupting dwarf galaxy in the Hercules Cluster, but we do not confirm an anomalously large half-light radius reported for the dwarf VCC 1661.
We investigate the motion of two immiscible fluids in a porous medium described by a two-phase flow system. In the capillary pressure relation, we include static and dynamic hysteresis. The model is well established in the context of the Richards equation, which is obtained by assuming a constant pressure for one of the two phases. We derive an existence result for this hysteresis two-phase model for non-degenerate permeability and capillary pressure curves. A discretization scheme is introduced and numerical results for fingering experiments are obtained. The main analytical tool is a compactness result for two variables that are coupled by a hysteresis relation.
Stimuli used in cued language switching studies typically consist of digits or pictures. However, the comparability between both stimulus types remains unclear. In the present study, we directly compared digit and picture naming in a German–English language switching experiment. Because digits represent a semantic group and contain many cognates, the experiment consisted of four conditions with different stimulus sets in each condition: digits, standard language switching pictures, pictures depicting cognates, and semantically-related pictures. Digit naming caused smaller switch costs than picture naming. The data suggest that this difference can be attributed to phonology. Both methodological and theoretical implications are discussed.
To investigate the impact of flat-detector computed tomography on the clinical assessment of patients with cavopulmonary connections, and to evaluate the obtained diagnostic accuracy and supplementary information, as well as the value of overlaid three-dimensional reconstructions on fluoroscopic images during catheter-based interventions.
We analysed 31 consecutive patients retrospectively in whom flat-detector computed tomography was used to visualise the cavopulmonary connection. We investigated patients with cavopulmonary connections either early post-operatively (first group), before converting to a total cavopulmonary connection (second group), and patients with failing total cavopulmonary connection (third group). Flat-detector computed tomography based on a single rotational angiography was used to create a three-dimensional vascular model. The clinical value of flat-detector computed tomography was evaluated using standard categories of diagnostic utility. Used contrast volume and radiation exposure were quantified.
Within 18 months, flat-detector computed tomography was performed in 31 cases with cavopulmonary connections. The median age was 1.9 years (range 0.3–43 years). In the first group, we found anomalies in 4 out of 8 cases, which led to therapeutic or prophylactic procedures; in the second and third groups, we performed interventions in 14 out of 23 cases. The overall clinical value was always rated superior to conventional biplane angiography. The median dose area product was 91.8 microgray square metres (range 33.0–679.3 microgray square metres). The required contrast medium was 2.08 millilitres per kilogram (range 0.66–4.7 millilitres per kilogram).
Flat-detector computed tomography improves the diagnostic accuracy in cavopulmonary connections and provides additional diagnostic information, which may lead to therapeutic or prophylactic procedures. Overlaid three-dimensional images on fluoroscopy facilitate and provide security for interventions.
During spike annealing of ultra-shallow junctions, large fractions of the dopants form a partially active pile-up at the interface between silicon and the screening oxide layer. In this paper, we show results of sheet resistance, SIMS and high resolution Elastic Recoil Detection measurements to investigate the physical and electrical behaviour of B and As dopant atoms at the interface.
Our results show that the fraction of dopants segregated at the interface is as high as 30-50% for B, but is dependent on dose and the type of screening oxide. Concentrations of up to 3e20cm-3 and more of active dopants are found on the Si side of the interface. The presence of nitrogen in the oxide at the interface causes a higher and sharper pile-up. Results indicate that a similar peak is expected for As, with active concentrations above 6e20cm-3. In an HF dip, the pile-up is removed together with the oxide or deactivated during native oxide regrowth.
Further experiments show that immediately after removing the screening oxide in an HF dip the sheet resistance for B decreases sharply due to carrier accumulation, then raises to about 6-9% above the initial level depending on the oxide and dopant species. The sharp decrease in resistance is not observed for As.
In this paper an overview of our developments towards industrialization of thin film silicon PV modules is presented. Amorphous silicon p-i-n solar cells have been developed in medium size single-chamber R&D KAI-M PECVD reactors. High initial efficiencies of 10.6 % and stabilized of 8.6 % could be achieved for a 1 cm2 a-Si:H p-i-n solar cell of 0.20 m thick i-layer deposited on TCO from Asahi U type (SnO2). On our in-house developed LPCVD ZnO we could further improve the stabilized a-Si:H p-i-n efficiency to a similar level of 8.5 %. Incorporating such cells in commercial available front TCO of lower quality still leads to high initial mini-module aperture efficiencies (10 × 10 cm2) of 9.1% and stabilized ones of 7.46% (independently measured by ESTI JRC-Ispra).
Transferring the processes from the KAI-M to the industrial size 1.1×1.25 m2 KAI-1200 R&D reactors resulted in a-Si:H modules of 110.6 W using commercial TCO, respectively 112.4 W when applying in-house developed LPCVD front ZnO. Both initial module performances have been independently measured by ESTI laboratories of JRC Ispra. A typical temperature coefficient for the module power of -0.22 %/°C (relative loss) has been deduced from temperature dependent I-V characteristics at ESTI laboratories of JRC Ispra. Finally, micromorph mini-modules of 10 % initial aperture efficiency have been fabricated.
Our knowledge about the chemical evolution of the more luminous dwarf spheroidal (dSph) galaxies is constantly growing. However, little is known about the enrichment of the ultrafaint systems recently discovered in large numbers in large Sky Surveys. Low-resolution spectroscopy and photometric data indicate that these galaxies are predominantly metal-poor. On the other hand, the most recent high-resolution abundance analyses indicate that some of these galaxies experienced highly inhomogenous chemical enrichment, where star formation proceeds locally on the smallest scales. Furthermore, these galaxy-contenders appear to contain very metal-poor stars with [Fe/H]< −3 dex and could be the sites of the first stars. Here, we consider the presently available chemical abundance information of the (ultra-) faint Milky Way satellite dSphs. In this context, some of the most peculiar element and inhomogeneous enrichment patterns will be discussed and related to the question of to what extent the faintest dSph candidates and outer halo globular clusters could have contributed to the metal-poor Galactic halo.
The M81 group is a highly interacting group consisting of a few large galaxies and about 40 dwarfs of both early- and late-type, thus making it an important nearby laboratory to study environmental effects and the role of interactions in the formation and evolution of dwarf galaxies. We are studying the resolved stellar populations of the early-type dwarf galaxies in this group with available HST/ACS data. We will show results on the metallicity distribution functions and on the potential presence of population gradients for these dwarf galaxies.
The potential of igneous quartz for providing a better understanding of magmatic processes is demonstrated by studying late-Hercynian rhyolites and granites from central and western Europe. Cathodoluminescence (CL) reveals growth patterns and alteration structures within igneous quartz reflecting the magma crystallisation history. The relatively stable and blue-dominant CL of zoned phenocrysts is principally related to variations in the Ti concentration, which is a function of the crystallisation temperature. The Al/Ti ratio of igneous quartz increases with progressive magma differentiation, as Ti is more compatible, compared to Al, Li, K, Ge, B, Fe, P during magma evolution. The red-dominant CL of the anhedral groundmass quartz in granite is unstable during electron bombardment and associated with OH- and H2O-bearing lattice defects. Thus, CL properties of quartz are different for rocks formed from H2O-poor and H2O-rich melts. Both groundmass and phenocrysts in granites are rich in alteration structures as a result of interaction with deuteric fluids during cooling, whereas phenocrysts in extrusive rocks do not usually contain such structures. The combined study of trace elements along with the analysis of quartz textures and melt inclusion inventories may reveal detailed PTX-paths of granite magmas. This study shows that quartz is a sensitive indicator for physico-chemical changes during the evolution of silicarich magmas. Common growth textures show a wide variety in quartz phenocrysts in rhyolites and some granites. This paper presents a classification of textures, which formed as a result of heterogeneous intra-granular lattice defects and impurities. The alternation of growth and resorption microtextures reflects stepwise adiabatic and non-adiabatic magma ascent, temporary storage of magma in reservoirs and mixing with more mafic, hotter magma. The anhedral groundmass quartz overgrowing early-magmatic phenocrysts in granites is free of growth zoning.
The objectives of the present study were to evaluate the effect of normobaric and hyperbaric O2 (HBO) on plasma antioxidants and biomarkers of oxidative stress in plasma and urine and to investigate the effect of a 4-week vitamin C plus E supplementation on HBO-induced oxidative stress. Nineteen healthy men were exposed to HBO (100 % O2; 240 kPa) before and after 4 weeks' supplementation with 500 mg vitamin C plus 165 mg α-tocopherol equivalents. Exposure to 21 % O2 at 100 kPa served as intra-individual controls (control). Samples for the analysis of plasma antioxidants and oxidative stress biomarkers were collected before and immediately after each treatment. The present results showed that when compared with ‘control’, a single exposure to HBO resulted in a decrease of plasma vitamin C (P = 0·027) and an increase of lipid peroxides (P = 0·0008) and urinary 8-oxo-deoxyguanosine (8-oxodG) excretion (P = 0·006). Oxidative stress was not prevented by a 4-week supplementation with vitamins C and E. HBO-induced changes in plasma parameters correlated with basal antioxidant levels. The increase of urinary 8-oxodG after HBO plus supplementation correlated negatively with vitamin E intake (P = 0·023). We concluded that in healthy men HBO caused oxidative stress, which could not be prevented by dietary vitamin C plus E supplementation. The present data support the idea that HBO is a suitable model for oxidative stress in healthy volunteers.
The Small Magellanic Cloud (SMC) is the only dwarf galaxy in the Local Group that is known to have formed and preserved populous star clusters continuously over the past 12 Gyr. Due to its proximity (≈ 60 kpc), stars can be resolved well below the oldest main sequence turnoff points. This facilitates accurate age and metallicity determinations without suffering from the age-metallicity degeneracy. Therefore, the SMC star clusters provide a unique closely spaced set of single-age, single-metallicity tracers to derive a well-sampled age-metallicity relation required for the understanding of the star formation history of this satellite galaxy. Up to date spectroscopically based metallicity estimates exist only for the small number of 7 clusters (Da Costa & Hatzidimitriou 1998). Our project now more than doubles the available data set by the observation of 10 additional clusters.
The observational evidence for kinematic substructure in Local Group dSphs is reviewed. The properties of these substructures are consistent with their being disrupted star clusters. The persistence of cold substructure argues strongly against the presence of dark matter cusps in the haloes of dSphs. A formation scenario for dSphs is described involving the merger of star clusters in the potential well of a low-mass dark matter halo.
A disaster is characterized by an imbalance between needs and supplies. In circumstances in which there occur mass casualties, it is not possible to provide care for all of the victims. Thus, it may be necessary to triage the casualties according to pre-established priorities. The performance of triage is associated with many ethical issues.
Currently, no Europe-wide agreement on triage and ethics exists. One system based on a categorization into four groups is proposed. Triage should be avoided whenever possible, but, when it is required, there is an obligation to respect human rights and the humanitarian laws, especially with reference to the Geneva Convention of 1864 and the Universal Declaration of Human Rights of 1948. The condition of informed consent must be followed, even in mass casualty situations. Triage always must follow established medical criteria and cannot be based on any other principles. Triage implies constant re-evaluation of victims as conditions of the victims and of available resources change continuously. In order to facilitate international coordination and cooperation, a universal classification system must be adopted.
To investigate cardiopulmonary performance in patients after a Fontan procedure, comparing it to patients following a Senning operation.
We studied 21 children, with a mean age of 11.1 years, after a total cavopulmonary anastomosis, comparing them to 13 with complete transposition after a Senning procedure, having a mean age of 11.8 years, and 21 control subjects with a mean age of 11.2 years. All were tested on a bicycle ergospirometer.
Peak consumption of oxygen, maximal work rate, peak oxygen pulse and endexpiratory pressure of carbon dioxide at a work rate of 1.5 Watt/kg were lowest in patients with a modified Fontan procedure, and highest in the control group (p ≤ 0.0278). Production of carbon dioxide, and minute ventilation at a work rate of 1.5 Watt/kg, was highest in the patients after Fontan procedure, and lowest in the healthy subjects (p ≤ 0.0163). Production of carbon dioxide per single breath was lower in those having a Fontan procedure (28.9 ml) than in the two other groups (35.1 ml; p = 0.0243). The tidal volume showed no significant differences between the three groups.
The reaction to exercise was identical qualitatively in both groups of patients, and comparable to the behaviour of patients with chronic heart failure. Quantitatively, the results of the patients following a Senning procedure lay between those of control subjects and those who had undergone a Fontan operation. The only exception was dead space ventilation, where the patients after a Fontan procedure differed from the two other groups because of their increased ventilation-perfusion mismatch.
The observed nonlinear saturation of crossflow vortices in the DLR swept-plate transition
experiment, followed by the onset of high-frequency signals, motivated us to
compute nonlinear equilibrium solutions for this flow and investigate their instability
to high-frequency disturbances. The equilibrium solutions are independent of
receptivity, i.e. the way crossflow vortices are generated, and thus provide a unique
characterization of the nonlinear flow prior to turbulence. Comparisons of these
equilibrium solutions with experimental measurements exhibit strong similarities. Additional
comparisons with results from the nonlinear parabolized stability equations
(PSE) and spatial direct numerical simulations (DNS) reveal that the equilibrium
solutions become unstable to steady, spatial oscillations with very long wavelengths
following a bifurcation close to the leading edge. Such spatially oscillating solutions
have been observed also in critical layer theory computations. The nature of the
spatial behaviour is herein clarified and shown to be analogous to that encountered
in temporal direct numerical simulations. We then employ Floquet theory to systematically
study the dependence of the secondary, high-frequency instabilities on
the saturation amplitude of the equilibrium solutions. With increasing amplitude, the
most amplified instability mode can be clearly traced to spanwise inflectional shear
layers that occur in the wake-like portions of the equilibrium solutions (Malik et al.
1994 call it ‘mode I’ instability). Both the frequency range and the eigenfunctions
resemble recent experimental measurements of Kawakami et al. (1999). However,
the lack of an explosive growth leads us to believe that additional self-sustaining
processes are active at transition, including the possibility of an absolute instability
of the high-frequency disturbances.
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