356 research outputs found
Extensional tectonics and collapse structures in the Suez Rift (Egypt)
The Suez Rift is a 300 km long and 50 to 80 km wide basin which cuts a granitic and metamorphic shield of Precambrian age, covered by sediments of Paleozoic to Paleogene age. The rift structure is dominated by tilted blocks bounded by NW-SE normal faults. The reconstruction of the paleostresses indicates a N 050 extension during the whole stage of rifting. Rifting began 24 My ago with dikes intrusions; main faulting and subsidence occurred during Early Miocene producing a 80 km wide basin (Clysmic Gulf). During Pliocene and Quaternary times, faulting is still active but subsidence is restricted to a narrower area (Present Gulf). On the Eastern margin of the gulf, two sets of fault trends are predominant: (1) N 140 to 150 E faults parallel to the gulf trend with pure dip-slip displacement; and (2) cross faults, oriented NOO to N 30 E that have a strike-slip component consistent with the N 050 E distensive stress regime. The mean dip cross fault is steeper (70 to 80 deg) than the dip of the faults parallel to the Gulf (30 to 70 deg). These two sets of fault define diamond shaped tilted block. The difference of mechanical behavior between the basement rocks and the overlying sedimentary cover caused structural disharmony and distinct fault geometries
Comparing eDNA metabarcoding and conventional pelagic netting to inform biodiversity monitoring in deep ocean environments
The performance of environmental DNA (eDNA) metabarcoding has rarely been evaluated against conventional sampling methods in deep
ocean mesopelagic environments. We assessed the biodiversity patterns generated with eDNA and two co-located conventional methods,
oblique midwater trawls and vertical multinets, to compare regional and sample-level diversity. We then assessed the concordance of ecological
patterns across water column habitats and evaluated how DNA markers and the level of sampling effort influenced the inferred community. We
found eDNA metabarcoding characterized regional diversity well, detecting more taxa while identifying similar ecological patterns as conventional
samples. Within sampling locations, eDNA metabarcoding rarely detected taxa across more than one replicate. While more taxa were found in
eDNA than oblique midwater trawls within sample stations, fewer were found compared to vertical multinets. Our simulations show greater
eDNA sampling effort would improve concordance with conventional methods. We also observed that using taxonomic data from multiple
markers generated ecological patterns most similar to those observed with conventional methods. Patterns observed with Exact Sequence
Variants were more stable across markers suggesting they are more powerful for detecting change. eDNA metabarcoding is a valuable tool for
identifying and monitoring biological hotspots but some methodological adjustments are recommended for deep ocean environments
A human coronavirus responsible for the common cold massively kills dendritic cells but not monocytes
Copyright @ 2012, American Society for Microbiology.Human coronaviruses are associated with upper respiratory tract infections that occasionally spread to the lungs and other organs. Although airway epithelial cells represent an important target for infection, the respiratory epithelium is also composed of an elaborate network of dendritic cells (DCs) that are essential sentinels of the immune system, sensing pathogens and presenting foreign antigens to T lymphocytes. In this report, we show that in vitro infection by human coronavirus 229E (HCoV-229E) induces massive cytopathic effects in DCs, including the formation of large syncytia and cell death within only few hours. In contrast, monocytes are much more resistant to infection and cytopathic effects despite similar expression levels of CD13, the membrane receptor for HCoV-229E. While the differentiation of monocytes into DCs in the presence of granulocyte-macrophage colony-stimulating factor and interleukin-4 requires 5 days, only 24 h are sufficient for these cytokines to sensitize monocytes to cell death and cytopathic effects when infected by HCoV-229E. Cell death induced by HCoV-229E is independent of TRAIL, FasL, tumor necrosis factor alpha, and caspase activity, indicating that viral replication is directly responsible for the observed cytopathic effects. The consequence of DC death at the early stage of HCoV-229E infection may have an impact on the early control of viral dissemination and on the establishment of long-lasting immune memory, since people can be reinfected multiple times by HCoV-229E
Experiments and cycling at the LHC prototype helf-cell
The first version of the LHC prototype half-cell has been in operation since February 1995. It consists of one quadrupole and three 10-m twin aperture dipole magnets which operate at 1.8 K. This experimental set-up has been used to observe and study phenomena which appear when the systems are assembled in one unit and influence one another. The 18-month long experimental program has validated the cryogenic system and yielded a number of results on cryogenic instrumentation, magnet protection and vacuum in particular under non-standard operating conditions. The program was recently complemented by the cycling experiment: it consisted in powering the magnets following the ramp rates which will be experienced by the magnets during an LHC acceleration. In order to simulate 10 years of routine operation of LHC, more than 2000 1-hour cycles were performed interleaved with provoked quenches. The objective of this experiment was to reveal eventual flaws in the design of components. The prototype half-cell performed to expectations showing no sign of failure of fatigue of components for more than 2000 cycles until one of the dipoles started exhibiting an erratic quench behavior
Internalising symptoms and working memory as predictors of mathematical attainment trajectories across the primary-secondary education transition
The transition from primary to secondary education is a critical period in early adolescence which is related to increased anxiety and stress, increased prevalence of mental health issues, and decreased maths performance, suggesting it is an important period to investigate maths attainment. Previous research has focused on anxiety and working memory as predictors of maths, without investigating any long-term effects around the education transition. This study examined working memory and internalizing symptoms as predictors of children's maths attainment trajectories (age 7–16) across the transition to secondary education using secondary longitudinal analysis of the Avon Longitudinal Study of Parents and Children (ALSPAC). This study found statistically significant, but very weak evidence for the effect of internalizing symptoms and working memory on maths attainment. Greater parental education was the strongest predictor, suggesting that children of parents with a degree (compared with those with a CSE) gain the equivalent of almost a year's schooling in maths. However, due to methodological limitations, the effects of working memory and internalizing symptoms on attainment cannot be fully understood with the current study. Additional research is needed to further uncover this relationship, using more time-appropriate measures
On the interplay between hypothermia and reproduction in a high arctic ungulate
For free-ranging animals living in seasonal environments, hypometabolism (lowered metabolic rate) and hypothermia (lowered body temperature) can be effective physiological strategies to conserve energy when forage resources are low. To what extent such strategies are adopted by large mammals living under extreme conditions, as those encountered in the high Arctic, is largely unknown, especially for species where the gestation period overlaps with the period of lowest resource availability (i.e. winter). Here we investigated for the first time the level to which high arctic muskoxen (Ovibos moschatus) adopt hypothermia and tested the hypothesis that individual plasticity in the use of hypothermia depends on reproductive status. We measured core body temperature over most of the gestation period in both free-ranging muskox females in Greenland and captive female muskoxen in Alaska. We found divergent overwintering strategies according to reproductive status, where pregnant females maintained stable body temperatures during winter, while non-pregnant females exhibited a temporary decrease in their winter body temperature. These results show that muskox females use hypothermia during periods of resource scarcity, but also that the use of this strategy may be limited to non-reproducing females. Our findings suggest a trade-of between metabolically driven energy conservation during winter and sustaining foetal growth, which may also apply to other large herbivores living in highly seasonal environments elsewhere.publishedVersio
“It’s the most important thing - I mean the schooling”: Father involvement in the education of children with autism
Father involvement in education has been shown to result in a range of positive outcomes for typically developing children. However, the nature of paternal involvement in the education of children with disabilities and especially autism has been under-researched and is little understood. This study aimed to explore the nature of the involvement of 25 UK fathers in the education and their children with autism, aged up to 19 years through the use of semi-structured interviews. Findings showed that fathers were highly engaged both directly and indirectly across several dimensions of their children’s education and schooling. Key areas of indirect engagement were involvement in administrative processes necessary for securing an appropriate educational placement; facilitating daily access to school and general support of children’s progress through attendance at school-based meetings and events. Direct support for learning occurred through homework assistance and working on school-related goals. Findings are discussed in relation to diversity and generative models of fatherhood. Implications for greater father inclusion in the education of children with autism are explored with reference to a gender-differentiated approach
MOST detects corotating bright spots on the mid-O type giant {\xi} Persei
We have used the MOST (Microvariability and Oscillations of STars)
microsatellite to obtain four weeks of contiguous high-precision broadband
visual photometry of the O7.5III(n)((f)) star {\xi} Persei in November 2011.
This star is well known from previous work to show prominent DACs (Discrete
Absorption Components) on time-scales of about 2 d from UV spectroscopy and NRP
(Non Radial Pulsation) with one (l = 3) p-mode oscillation with a period of 3.5
h from optical spectroscopy. Our MOST-orbit (101.4 min) binned photometry fails
to reveal any periodic light variations above the 0.1 mmag 3-sigma noise level
for periods of hours, while several prominent Fourier peaks emerge at the 1
mmag level in the two-day period range. These longer-period variations are
unlikely due to pulsations, including gravity modes. From our simulations based
upon a simple spot model, we deduce that we are seeing the photometric
modulation of several co-rotating bright spots on the stellar surface. In our
model, the starting times (random) and lifetimes (up to several rotations) vary
from one spot to another yet all spots rotate at the same period of 4.18 d, the
best-estimated rotation period of the star. This is the first convincing
reported case of co-rotating bright spots on an O star, with important
implications for drivers of the DACs (resulting from CIRs - Corotating
Interaction Regions) with possible bright-spot generation via a breakout at the
surface of a global magnetic field generated by a subsurface convection zone.Comment: 9 pages, 4 figures, 2 tables, MNRAS in pres
Acceleration of High Intensity Proton Beams
In 1998 the CERN SPS accelerator finished a five years long program providing 450GeV proton beams for neutrino physics. These experiments required the highest possible beam intensity the SPS can deliver. During the last five years the maximum proton intensity in the SPS has steadily been increased to a maximum of 4.8 1013 protons per cycle. In order to achieve these intensities a careful monitoring and improvement of the vertical aperture was necessary. Improved feedback systems on the different RF cavities were needed in order to avoid instabilities. Also the quality (emittance and extraction spill) of the injector, the CERN PS, had be optimised
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