272 research outputs found
Considering Childhood Obesity through an Investigation of Maternal/Infant Factors and the Acceptability of a Text Message-Based Intervention.
Ph.D. Thesis. University of Hawaiʻi at Mānoa 2018
Dyslexia or Literacy Difficulties: What Difference Does a Label Make? Exploring the Perceptions and Experiences of Young People
This study explores the views of young people (YP), with and without self-reported dyslexia or literacy difficulties, focussing on the impact of labels. Qualitative data were gathered through an online survey and individual interviews. The study highlights how the presence or absence of a label can impact people’s perceptions. Dyslexia was perceived as biological in origin; therefore, YP with the label were seen as not to blame for their difficulties. However, more negative judgements were made about YP without the label but with the same difficulties. Participants viewed the label as important for gaining support, yet highlighted the potential for discrimination in terms of access to diagnosis and resources. What was important to participants with dyslexia was not necessarily the label but the support that they received and how they were viewed by others. Implications for school professionals are discussed in terms of ensuring that YP feel empowered by the way they are described
Ionic Coulomb blockade and the determinants of selectivity in the NaChBac bacterial sodium channel
Mutation-induced transformations of conductivity and selectivity in NaChBac bacterial channels are studied experimentally and interpreted within the framework of ionic Coulomb blockade (ICB), while also taking account of resonant quantised dehydration (QD) and site protonation. Site-directed mutagenesis and whole-cell patch-clamp experiments are used to investigate how the fixed charge Qf at the selectivity filter (SF) affects both valence selectivity and same-charge selectivity. The new ICB/QD model predicts that increasing |Qf | should lead to a shift in selectivity sequences towards larger ion sizes, in agreement with the present experiments and with earlier work. Comparison of the model with experimental data leads to the introduction of an effective charge Qf∗ at the SF, which was found to differ between Aspartate and Glutamate charged rings, and also to depend on position within the SF. It is suggested that protonation of the residues within the restricted space of the SF is important in significantly reducing the effective charge of the EEEE ring. Values of Qf∗ derived from experiments on divalent blockade agree well with expectations based on the ICB/QD model and have led to the first demonstration of ICB oscillations in Ca2+ conduction as a function of the fixed charge. Preliminary studies of the dependence of Ca2+ conduction on pH are qualitatively consistent with the predictions of the model
Theory and Experiments on Multi-Ion Permeation and Selectivity in the NaChBac Ion Channel
The highly selective permeation of ions through biological ion channels is an unsolved problem of noise and fluctuations. In this paper, we motivate and introduce a non-equilibrium and self-consistent multi-species kinetic model, with the express aims of comparing with experimental recordings of current versus voltage and concentration and extracting important permeation parameters. For self-consistency, the behavior of the model at the two-state, i.e., selective limit in linear response, must agree with recent results derived from an equilibrium statistical theory. The kinetic model provides a good fit to data, including the key result of an anomalous mole fraction effect
SGR J1550-5418 bursts detected with the Fermi Gamma-ray Burst Monitor during its most prolific activity
We have performed detailed temporal and time-integrated spectral analysis of
286 bursts from SGR J1550-5418 detected with the Fermi Gamma-ray Burst Monitor
(GBM) in January 2009, resulting in the largest uniform sample of temporal and
spectral properties of SGR J1550-5418 bursts. We have used the combination of
broadband and high time-resolution data provided with GBM to perform
statistical studies for the source properties. We determine the durations,
emission times, duty cycles and rise times for all bursts, and find that they
are typical of SGR bursts. We explore various models in our spectral analysis,
and conclude that the spectra of SGR J1550-5418 bursts in the 8-200 keV band
are equally well described by optically thin thermal bremsstrahlung (OTTB), a
power law with an exponential cutoff (Comptonized model), and two black-body
functions (BB+BB). In the spectral fits with the Comptonized model we find a
mean power-law index of -0.92, close to the OTTB index of -1. We show that
there is an anti-correlation between the Comptonized Epeak and the burst
fluence and average flux. For the BB+BB fits we find that the fluences and
emission areas of the two blackbody functions are correlated. The
low-temperature BB has an emission area comparable to the neutron star surface
area, independent of the temperature, while the high-temperature blackbody has
a much smaller area and shows an anti-correlation between emission area and
temperature. We compare the properties of these bursts with bursts observed
from other SGR sources during extreme activations, and discuss the implications
of our results in the context of magnetar burst models.Comment: 13 pages, 10 figures, 2 tables; minor changes, ApJ in pres
Fermi observations of high-energy gamma-ray emission from GRB 080825C
The Fermi Gamma-ray Space Telescope (FGST) has opened a new high-energy
window in the study of Gamma-Ray Bursts (GRBs). Here we present a thorough
analysis of GRB 080825C, which triggered the Fermi Gamma-ray Burst Monitor
(GBM), and was the first firm detection of a GRB by the Fermi Large Area
Telescope (LAT). We discuss the LAT event selections, background estimation,
significance calculations, and localization for Fermi GRBs in general and GRB
080825C in particular. We show the results of temporal and time-resolved
spectral analysis of the GBM and LAT data. We also present some theoretical
interpretation of GRB 080825C observations as well as some common features
observed in other LAT GRBs.Comment: 18 pages, 7 figures. Accepted for publication in ApJ. Corresponding
authors: A. Bouvier, J. Granot, A.J. van der Hors
Imaging in the time of NFD/NSF: do we have to change our routines concerning renal insufficiency?
To date there are potential chronology-based but not conclusive reasons to believe that at least some of the gadolinium complexes play a causative role in the pathophysiology of nephrogenic systemic fibrosis (NSF) or nephrogenic fibrosing dermopathy (NFD). Still, the exact pathogenesis and the risk for patients is unclear beside the obvious connection to moderate to severe renal insufficiency. So far, MR imaging with Gd-enhancement was regarded as the safest imaging modality in these patients—the recent development creates tremendous uncertainty in the MR-community. Nevertheless, one should remember that, despite the over 200 cases of NSF and about 100 with proven involvement of Gd3+, the vast majority of over 200 million patients exposed to gadolinium since the 1980s have tolerated these agents well. Importantly, NSF is a rare disease and does not appear to occur in patients without renal impairment. Many patients and researchers have undergone MR investigations with Gd exposure in the past. For those, it is essential to know about the safety of the agents at normal renal function. We can hope that pharmacoepidemiological and preclinical studies will allow us to better understand the pathophysiology and role of the various MR contrast agents in the near future
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