880 research outputs found
Transitions in the morphological features, habitat use, and diet of young-of-the-year goosefish (Lophius americanus)
This study was designed to improve our understanding of transitions in the early life history and the distribution, habitat use, and diets for young-of-the-year (YOY) goosefish
(Lophius americanus) and, as a result, their role in northeastern U.S. continental shelf ecosystems. Pelagic juveniles (>12 to ca. 50 mm total length [TL]) were distributed over most portions of the continental shelf in the Middle Atlantic Bight, Georges Bank, and into the Gulf of Maine. Most individuals settled by 50â85 mm TL and reached approximately 60â120 mm TL by one year of age. Pelagic YOY fed on chaetognaths, hyperiid amphipods, calanoid copepods, and ostracods, and benthic YOY had a varied diet of fishes and benthic crustaceans. Goosefish are
widely scattered on the continental shelf in the Middle Atlantic Bight during their early life history and once settled, are habitat generalists, and thus play a role in many continental shelf habi
Ultrashort pulse characterization by spectral shearing interferometry with spatially chirped ancillae
We report a new version of spectral phase interferometry for direct electric
field reconstruction (SPIDER), which enables consistency checking through the
simultaneous acquisition of multiple shears and offers a simple and precise
calibration method. By mixing the test pulse with two spatially chirped ancilla
fields we generate a single-shot interferogram which contains multiple shears,
the spectral amplitude of the test pulse, and the reference phase, which is
accurate for broadband pulses. All calibration parameters - shear,
upconversion-frequency and reference phase position - can be accurately
obtained from a single calibration trace.Comment: 11 pages, 7 figure
Genetic and environmental risk factors for sexual distress and its association with female sexual dysfunction
A. Burri, Q. Rahman and T. Spector (2011). Genetic and environmental risk factors for sexual distress and its association with female sexual dysfunction. Psychological Medicine, 41, pp 2435-2445. Copyright © Cambridge University Press 2011. http://dx.doi.org/10.1017/S003329171100049
Attosecond sampling of arbitrary optical waveforms
Advances in the generation of ultrashort laser pulses, and the emergence of new research areas such as attosecond science, nanoplasmonics, coherent control, and multidimensional spectroscopy, have led to the need for a new class of ultrafast metrology that can measure the electric field of complex optical waveforms spanning the ultraviolet to the infrared. Important examples of such waveforms are those produced by spectral control of ultrabroad bandwidth pulses, or by Fourier synthesis. These are typically tailored for specific purposes, such as to increase the photon energy and flux of high-harmonic radiation, or to control dynamical processes by steering electron dynamics on subcycle time scales. These applications demand a knowledge of the full temporal evolution of the field. Conventional pulse measurement techniques that provide estimates of the relative temporal or spectral phase are unsuited to measure such waveforms. Here we experimentally demonstrate a new, all-optical method for directly measuring the electric field of arbitrary ultrafast optical waveforms. Our method is based on high-harmonic generation (HHG) driven by a field that is the collinear superposition of the waveform to be measured with a stronger probe laser pulse. As the delay between the pulses is varied, we show that the field of the unknown waveform is mapped to energy shifts in the high-harmonic spectrum, allowing a direct, accurate, and rapid retrieval of the electric field with subcycle temporal resolution at the location of the HHG
âDoes it do what it says on the tin?â â An exploratory case study into how an additional resource provision in a mainstream secondary school facilitates inclusion for young people with autism spectrum disorder (ASD).
The drive toward inclusion for autistic children and young people, has led to the majority of these students being educated within mainstream schools (DfE, 2021/22). School placement decisions for these students are generally based on individual needs and resources available. One option that is slowly growing in popularity based on parental satisfaction and aimed at promoting inclusion in mainstream education is that of additional resource provisions (ARPs) (Fredrickson et al., 2010). Currently there is little research on ARPs and even less eliciting the views of autistic students who access support from these ARPs. Therefore, the aim of this research was to conduct an exploratory case study of an ARP attached to a secondary mainstream school and aimed to explore the available support through observations and a staff focus group. The research also aimed to elicit the views of 7 autistic students through semistructured interviews on their experiences of being supported by an ARP, including what they found helpful and what they experienced as being barriers to effective support. Reflexive Thematic Analysis was used to analysis the data collected and indicated that the ARP in this study offers several benefits that supports students to access the mainstream school, including keyworkers being central to facilitating individualised packages of support. However, findings also highlighted areas of improvement, including developing the wider school ethos and culture, through training and attention to school policies. Furthermore, findings called for more collaborative working between the ARP staff and mainstream teachers with the aim of having a shared understanding of how best to support this population of students. The unique insight into studentâs experiences of available support aims to inform future thinking on what students may find works well and what might need further consideration to supporting these students to access the mainstream setting
Gains From Training in Phonological Awareness in Kindergarten Predict Reading Comprehension in Grade 9
The effects of a kindergarten training program in phonological awareness with 209 Swedish-speaking children were followed up until the end of Grade 9. Initial levels of letter knowledge and phonological awareness were positively associated with the level of decoding skill in Grade 3 but not with its growth afterward. The intervention group performed significantly better in decoding in Grade 3, and the difference was maintained until Grade 6. The trained children also scored higher in Grade 9 reading comprehension. Although the results give empirical support for a connection between early phonological awareness training, later word decoding development, and still later reading comprehension, the theoretical explanation for the link between especially word decoding and reading comprehension is far from clear.</p
Optimisation of Quantum Trajectories Driven by Strong-field Waveforms
Quasi-free field-driven electron trajectories are a key element of
strong-field dynamics. Upon recollision with the parent ion, the energy
transferred from the field to the electron may be released as attosecond
duration XUV emission in the process of high harmonic generation (HHG). The
conventional sinusoidal driver fields set limitations on the maximum value of
this energy transfer, and it has been predicted that this limit can be
significantly exceeded by an appropriately ramped-up cycleshape. Here, we
present an experimental realization of such cycle-shaped waveforms and
demonstrate control of the HHG process on the single-atom quantum level via
attosecond steering of the electron trajectories. With our optimized optical
cycles, we boost the field-ionization launching the electron trajectories,
increase the subsequent field-to-electron energy transfer, and reduce the
trajectory duration. We demonstrate, in realistic experimental conditions, two
orders of magnitude enhancement of the generated XUV flux together with an
increased spectral cutoff. This application, which is only one example of what
can be achieved with cycle-shaped high-field light-waves, has farreaching
implications for attosecond spectroscopy and molecular self-probing
Analysis of a model with a common source of CP violation
We work in a model where all CP violating phenomena have a common source. CP
is spontaneously broken at a large scale through the phase of a complex
singlet scalar. An additional singlet vector-like down-type quark
relates this high scale CP violation to low energy. We quantitatively analyze
this model in the quark sector. We obtain the numerical values of the
parameters of the Lagrangian in the quark sector for a specific ansatz of the
down-type quark mass matrix where the weak phase is generated
minimally. vertex will modify in presence of the extra vector-like
down-type quark. From the experimental lower bound of the partial decay width
we find out the lower bound of the additional down-type quark
mass. Tree level flavor changing neutral current appears in this model due to
the presence of the extra vector-like down-type quark. We give the range of
values of the mass splitting in system
using SM box, mediating tree level and mediating one loop diagrams
together for both . We find out the analytical expression for
in this model from standard box, and Higgs mediated penguin
diagrams for system, . From this we numerically
evaluate the decay width difference . We
also find out the numerical values of the CP asymmetry parameters and
for the decays and
respectively. We get the lower bound of the scale through the upper bound
of the strong CP phase.Comment: 20 pages, no figures New materials and references have been added.
Text has been modified. To be appear in J.Phys.
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