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During the Epoch of Reionization (EoR), feedback effects reduce the efficiency of star formation process in small halos or even fully quench it. The galaxy luminosity function (LF) may then turn over at the faint-end. We analyze the number counts of z > 5 galaxies observed in the fields of four Frontier Fields (FFs) clusters and obtain constraints on the LF faint-end: for the turn-over magnitude at z ∼ 6, MUVT ≳-13.3; for the circular velocity threshold of quenching star formation process, vc* ≲ 47 km s−1. We have not yet found significant evidence of the presence of feedback effects suppressing the star formation in small galaxies.
The bombardment of ions and electrons at the substrate has been studied by
varying the magnetic field distribution and the grid-target distance in a
triode magnetron sputtering system. The substrate temperature was correlated
with the substrate current density and with the type of species bombarding
the substrate. The results indicate a possibility to modify and control the
bombardment at the substrate surface from predominantly electronic to
predominantly ionic, which increases the substrate temperature from 383 K to
473 K, respectively.
Ortles mountain (3905 m a.s.l.), South Tyrol, Italy, is the highest mountain of the Eastern European Alps, and its upper glacier, Alto dell’Ortles, presents a unique opportunity to obtain the first paleoenvironmental record from an ice core in this area. To study the suitability of this glacier as a drilling site, in 2009 we performed the first preliminary study of its glaciological characteristics at ˜3830 m a.s.l. The maximum thickness is ˜75 m, and lamination of the exposed ice layers is excellent down to bedrock. Firn and ice lenses were observed in a 10 m shallow core, and the firn/ice transition was below ˜24m. The seasonal chemical signal is clearly preserved only within the uppermost 2008 and 2009 snow/firn. A simple mass-balance model, the incipient ‘smoothing’ of the chemical record, and the observed ice lenses provide evidence that melting, infiltration and refreezing cycles occurred within the firn layers formed before 2008. Nevertheless, the mass balance of the upper part of Alto dell’Ortles was positive (˜800mma_1) during the last few years. We suggest that an environmental history is likely to be well preserved only within the ice layers formed before ˜1980, when summer air temperature was ˜2°C colder than today in this area. Clearly the continued warming trend predicted to occur over the next few decades, and the consequent increase in frequency and/or intensity of infiltration processes, will endanger the preservation of the glacial archive conserved in the deep ice layers of Ortles mountain.
This study evaluated the influence of cognitive reserve on
neuropsychological test performance in 198 patients infected with the
hepatitis C virus. IQ scores, educational level, and occupational rating
were combined to calculate a Cognitive Reserve Score (CRS) for each
patient. Similar to studies of infection with the human immunodeficiency
virus, there was a significantly increased risk of impairment in
neuropsychological test performance in individuals with lower CRSs. It is
important to account for CRS when assessing cognitive findings in
large-scale clinical trials. (JINS, 2007, 13,
687–692.)Financial relationships of
the authors with Hoffmann-La Roche, Inc., are as follows: K.L. Lindsay is
a consultant and receives research support; A.S.F. Lok is a consultant and
receives grant support; and R.J. Fontana is on the speaker's bureau.
Authors with no financial relationships related to this project are as
follows: L.A. Bieliauskas, C. Back-Madruga, E.C. Wright, and Z.
The objective of this analysis was to test the validity of the estimates of energy expenditure and sedentary lifestyle obtained through a self-administered questionnaire of physical activity for Spanish-speaking people adapted from US questionnaires (Nurses' Health Study and Health Professionals' Follow-up Study) using a triaxial accelerometer (RT3 Triaxial Research Tracker) as the reference.
Design and setting: Validation study, calculating the non-parametric correlation coefficients between the level of physical activity and sedentary lifestyle collected by the self-administered questionnaire and the triaxial accelerometer measurements. Percentage of misclassification and kappa coefficients were also calculated.
The study population consisted of a sample of 40 obese women who were participants of the SUN (Seguimiento Universidad de Navarra) project (a prospective cohort study among Spanish university alumni). They were selected because of their peculiar metabolic characteristics, in the search for a sub-optimal scenario for validity.
Physical activity during leisure time (estimated as MET-h week-1) derived from the self-administered questionnaire moderately correlated with kcal day-1 assessed through the accelerometer (Spearman's ρ = 0.507, 95% confidence interval (CI) 0.232, 0.707). The Spearman correlation between the ratio of sedentary lifestyle to physical activity obtained through the questionnaire and the direct estimation (RT3) was -0.578 (95% CI -0.754, -0.325). The kappa index was 0.25 (P = 0.002) when assessing the cross-classification into quintiles and 0.41 for the dichotomous estimation of a sedentary lifestyle. Only 2.5% of participants were misclassified by the questionnaire more than two quintiles apart from the estimates of the RT3.
The moderate values obtained for correlation in a sub-optimal scenario for validity and the low percentage of extreme misclassification suggest the validity of the questionnaire to assess physical activity in Spanish-speaking women aged 20–50 years.
We sought to determine the source of a norovirus outbreak among attendees of 46 weddings taking place during a single weekend. Norovirus-compatible illness was experienced by 332 (39%) of wedding guests surveyed; the outbreak affected up to 2700 persons. Illness was associated with eating wedding cake provided by a bakery common to the weddings (adjusted RR 4·5, P<0·001). A cake requiring direct hand contact during its preparation accounted for the majority of illness. At least two bakery employees experienced norovirus-compatible illness during the week preceding the weddings. Identical sequence types of norovirus were detected in stool specimens submitted by two wedding guests, a wedding hall employee, and one of the ill bakery employees. It is likely that one or more food workers at the bakery contaminated the wedding cakes through direct and indirect contact. These findings reinforce the necessity of proper food-handling practices and of policies that discourage food handlers from working while ill.
In 1997 a new collaborative research project was initiated by the British School at Rome. This project draws on a variety of sources of archaeological information to explore the regional impact of the City of Rome throughout the period from 1000 BC to AD 1300. The project provides a common collaborative research framework which brings together a range of archaeologists and historians working in various institutions. In this paper those involved in different aspects of this new project outline their work and its overall objectives.
Normal and tangential resistance coefficients are calculated for a rigid slender body close to a planar no-slip boundary or midway between and close to two such boundaries. The important length scale is found to be the separation distance from the boundaries, and the forces per unit length acting on the slender body are approximately constant along most of its length. Owing to the presence of the walls, the ratio of the normal and tangential resistance coefficients can be greater than 2, its maximum limiting value in the infinite-fluid case. Applications to the movements of flagellated micro-organisms are discussed.
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