161 research outputs found
Differential parent and teacher reports of school readiness in a disadvantaged community
Differential ratings by multiple informants are an important issue in survey design. Although much research has focused on differential reports of child behaviour, discrepancies between parent and teacher reports of childrenās school readiness are less explored.
Report on Children's Profile at School Entry 2008-2009: Evaluation of the 'Preparing For Life' Early Childhood Intervention Programme
The Children's Profile at School Entry (CPSE) was conducted by the UCD Geary Institute who have been commissioned by the Northside Partnership to assess the levels of school readiness in a designated disadvantaged community of Ireland, as part of an overall evaluation of the Preparing for Life (PFL) early childhood intervention programme.
Structural studies of the trivalent lanthanides at ultra-high pressures
The lanthanide and actinide metals have complex electronic and magnetic
behaviour at high pressures and low temperatures, respectively, owing to the
f electrons buried within the atoms participating in the bonding of those metals.
As one traverses the lanthanide series with increasing Z at ambient conditions,
each element adds one electron to the 4f shell, starting with cerium (Ce) and
ending with a full 4f electron shell in lutetium (Lu). This thesis focuses on
the trivalent lanthanides, which are considered to be all the lanthanides except
Ce, europium (Eu) and ytterbium (Yb), and their structural systematics at
high pressures. The trivalent lanthanides exhibit a common, pressure-induced,
structural phase transition sequence: hexagonal close-packed (hcp) ! Sm-type
or -Sm ! double-hcp (dhcp) ! face-centred cubic (fcc) ! distorted-fcc (dfcc)
! \volume-collapsed". This sequence is thought to arise from the 5s ! 5d
transfer of electrons, and, at ultra-high pressures, from the 4f electrons becoming
delocalised and then participating in the bonding of these elements, leading to
volume-collapsed phases with low-symmetry structures. However, there is still
debate over the exact structures of the low-symmetry collapsed phases.
This thesis describes x-ray di raction studies of the high-pressure structures of the
collapsed phases of six trivalent lanthanide elements (neodymium (Nd), samarium
(Sm), praseodymium (Pr), gadolinium (Gd), terbium (Tb) and dysprosium
(Dy)), and also yttrium (Y) { a rare-earth element. Using diamond anvil cell
(DAC) techniques and x-ray powder di raction at the Diamond Light Source
and PETRA-III synchrotrons, the structures of the collapsed phases of six of the
seven elements are found to be face-centred orthorhombic, spacegroup Fddd, with
either 8 atoms (Nd and Sm) or 16 atoms (Gd, Tb, Dy and Y) in the unit cell.
The 8-atom structure (oF8) is the same as that seen previously in the actinides
plutonium (Pu), americium (Am), curium (Cm) and californium (Cf), greatly
strengthening the structural relationships between the 4f lanthanides and the 5f
actinides. The 16-atom structure (oF16) found in Gd, Tb, Dy and Y is previously
unknown in the elements, but, along with the oF8 structure, and hP3 structure
seen in Nd and Sm at lower pressures, it is a member of a new structural family
comprising di erent stackings of quasi-hcp layers.
This thesis also describes higher-pressure studies with the aim of determining the
structural systematics of the post-oF8/oF16 phases. Pr and Nd have been shown
to exhibit the -uranium ( -U) structure, oC4, in their collapsed phases. In Pr,
a primitive orthorhombic structure was previously reported above 147 GPa, the
post- -U phase, a structure not seen in any other element. This thesis shows that
the true structure is body-centred tetragonal, the same as the highest-pressure
phase seen in the neighbouring lanthanide Ce, and also in the actinides thorium
(Th) and uranium (U), suggesting that it is the \next" structure in the transition
sequence of the trivalent lanthanides.
This work contained in this thesis completely rewrites the structural behaviour
of the trivalent lanthanide elements at high-pressure and reveals that the highpressure
behaviour of the lanthanide and actinide metals is much more similar
than previously believed.
i
Tackling loneliness and isolation in older adults with virtual reality: How do we move forward?
Current trends in gerontology conceptualize Virtual Reality (VR) as a tool for rehabilitation, lauding its potential for cognitive rehabilitation or as an intervention to reduce cognitive function decline (D'Cunha, et al., 2019) (Bauer & Andringa, 2020) (Sayma, Tuijt, Cooper, & Walters, 2020) (Moyle, Jones, Dwan, & Petrovich, 2018). However, we must take a critical stance and identify not just the potential positive impact, but also how things may go wrong without appropriate guidelines, and the need for careful design around the interaction affordances of the technology. We conducted co-discovery and co-design workshops involving expert stakeholders and older adults (N=20) over a period of 6 month, involving practical activities including user personas and focus groups to understand the complexities of loneliness and identify possible solutions with VR. Based on our findings we focus our argument on two key factors in the conceptualization of loneliness: spaces, and activities which may take place within said spaces. we present our reconceptualization of VR as a tool for group activities instead of passive consumption of content and make a first step suggestions to the community for reducing feelings of loneliness with VR
Polyethyleneimine-mediated transfection of cultured postmitotic neurons from rat sympathetic ganglia and adult human retina
BACKGROUND: Chemical methods of transfection that have proven successful with cell lines often do not work with primary cultures of neurons. Recent data, however, suggest that linear polymers of the cation polyethyleneimine (PEI) can facilitate the uptake of nucleic acids by neurons. Consequently, we examined the ability of a commercial PEI preparation to allow the introduction of foreign genes into postmitotic mammalian neurons. Sympathetic neurons were obtained from perinatal rat pups and maintained for 5 days in vitro in the absence of nonneuronal cells. Cultures were then transfected with varying amounts of a plasmid encoding either E. coli Ī²-galactosidase or enhanced green fluorescence protein (EGFP) using PEI. RESULTS: Optimal transfection efficiency was observed with 1 Ī¼g/ml of plasmid DNA and 5 Ī¼g/ml PEI. Expression of Ī²-galactosidase was both rapid and stable, beginning within 6 hours and lasting for at least 21 days. A maximum yield was obtained within 72 hours with ā¼ 9% of the neurons expressing Ī²-galactosidase, as assessed by both histochemistry and antibody staining. Cotransfection of two plasmids encoding reporter genes was achieved. Postmitotic neurons from adult human retinal cultures also demonstrated an ability to take up and express foreign DNA using PEI as a vector. CONCLUSIONS: These data suggest that PEI is a useful agent for the stable expression of plasmid-encoded genes in neuronal cultures
Recommended from our members
Separation of trait and state in stuttering
Stuttering is a disorder in which the smooth flow of speech is interrupted. People who stutter show structural and functional abnormalities in the speech and motor system. It is unclear whether functional differences reflect general traits of the disorder or are specifically related to the dysfluent speech state. We used a hierarchical approach to separate state and trait effects within stuttering. We collected sparseāsampled functional MRI during two overt speech tasks (sentence reading and picture description) in 17 people who stutter and 16 fluent controls. Separate analyses identified indicators of: (1) general traits of people who stutter; (2) frequency of dysfluent speech states in subgroups of people who stutter; and (3) the differences between fluent and dysfluent states in people who stutter. We found that reduced activation of left auditory cortex, inferior frontal cortex bilaterally, and medial cerebellum were general traits that distinguished fluent speech in people who stutter from that of controls. The stuttering subgroup with higher frequency of dysfluent states during scanning (n = 9) had reduced activation in the right subcortical grey matter, left temporoāoccipital cortex, the cingulate cortex, and medial parietoāoccipital cortex relative to the subgroup who were more fluent (n = 8). Finally, during dysfluent states relative to fluent ones, there was greater activation of inferior frontal and premotor cortex extending into the frontal operculum, bilaterally. The above differences were seen across both tasks. Subcortical state effects differed according to the task. Overall, our data emphasise the independence of trait and state effects in stuttering
Brain activity measured by functional brain imaging predicts breathlessness improvement during pulmonary rehabilitation
Background Chronic breathlessness in chronic obstructive pulmonary disease (COPD) is effectively treated with pulmonary rehabilitation. However, baseline patient characteristics predicting improvements in breathlessness are unknown. This knowledge may provide better understanding of the mechanisms engaged in treating breathlessness and help to individualise therapy. Increasing evidence supports the role of expectation (ie, placebo and nocebo effects) in breathlessness perception. In this study, we tested functional brain imaging markers of breathlessness expectation as predictors of therapeutic response to pulmonary rehabilitation, and asked whether D-cycloserine, a brain-active drug known to influence expectation mechanisms, modulated any predictive model.
Methods Data from 71 participants with mild-to-moderate COPD recruited to a randomised double-blind controlled experimental medicine study of D-cycloserine given during pulmonary rehabilitation were analysed (ID: NCT01985750). Baseline variables, including brain-activity, self-report questionnaires responses, clinical measures of respiratory function and drug allocation were used to train machine-learning models to predict the outcome, a minimally clinically relevant change in the Dyspnoea-12 score.
Results Only models that included brain imaging markers of breathlessness-expectation successfully predicted improvements in Dyspnoea-12 score (sensitivity 0.88, specificity 0.77). D-cycloserine was independently associated with breathlessness improvement. Models that included only questionnaires and clinical measures did not predict outcome (sensitivity 0.68, specificity 0.2).
Conclusions Brain activity to breathlessness related cues is a strong predictor of clinical improvement in breathlessness over pulmonary rehabilitation. This implies that expectation is key in breathlessness perception. Manipulation of the brainās expectation pathways (either pharmacological or non-pharmacological) therefore merits further testing in the treatment of chronic breathlessness
- ā¦