905 research outputs found
Better communication research project : language and literacy attainment of pupils during early years and through KS2 : does teacher assessment at five provide a valid measure of children's current and future educational attainments?
It is well-established that language skills are amongst the best predictors of educational success. Consistent with this, findings from a population-based longitudinal study of parents and children in the UK indicate that language development at the age of two years predicts childrenâs performance on entering primary school. Moreover, children who enter school with poorly developed speech and language are at risk of literacy difficulties and educational
underachievement is common in such children. Whatever the origin of childrenâs problems with language and communication, the poor educational attainment of children with language learning difficulties is an important concern for educational polic
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Aboveground Biomass and Carbon Storage Capacities of a Western Amazonian Primary and Secondary Growth Forest
Amazonian tropical forests are critical to global carbon cycling and sequestration, and in direct danger from deforestation. In order to contribute to limited existing literature on the carbon sequestration potential of secondary forest ecosystems and their aboveground biomass (AGB), we established permanent 0.2-ha plots in a primary and a secondary forest near Iquitos, Loreto, Peru. We measured diameter at breast height (DBH), tree height, and wood density for trees â„10 cm DBH and took the diameter of lianas at 30 cm shoot extension, then used published allometric equations to estimate AGB and compare it between forests. Trees within the primary forest plot had a significantly greater mean DBH and higher mean wood density, as well as a greater overall AGB than trees within the secondary forest. AGB was calculated to be 322.05 Mg/ha for the primary forest and 51.17 Mg/ha for the secondary forest. Sequestered carbon quantities were 151.36 Mg/ha and 24.05 Mg/ha, respectively. Higher estimates of stored carbon within the primary forest are attributed to old- growth trees with large DBH values and increased wood density, and discrepancies between our carbon estimates for the secondary forest and past estimates for the same site suggest the need to focus more research and attention on allometric equation use. The results of this study provide a potential incentive for carbon sequestration funding to be awarded to the primary forest property studied and establish a foundation for future estimations of the carbon storage capacities of tropical secondary forests
Impact of sea ice on the marine iron cycle and phytoplankton productivity
Iron is a key nutrient for phytoplankton growth in the surface ocean. At high
latitudes, the iron cycle is closely related to the dynamics of sea ice. In
recent decades, Arctic sea ice cover has been declining rapidly and Antarctic
sea ice has exhibited large regional trends. A significant reduction of sea
ice in both hemispheres is projected in future climate scenarios. In order to
adequately study the effect of sea ice on the polar iron cycle, sea ice
bearing iron was incorporated in the Community Earth System Model (CESM). Sea
ice acts as a reservoir for iron during winter and releases the trace metal
to the surface ocean in spring and summer. Simulated iron concentrations in
sea ice generally agree with observations in regions where iron
concentrations are relatively low. The maximum iron concentrations simulated
in Arctic and Antarctic sea ice are much lower than observed, which is likely
due to underestimation of iron inputs to sea ice or missing mechanisms. The
largest iron source to sea ice is suspended sediments, contributing fluxes of
iron of 2.2 Ă 108 mol Fe monthâ1 in the Arctic and
4.1 Ă 106 mol Fe monthâ1 in the Southern Ocean during
summer. As a result of the iron flux from ice, iron concentrations increase
significantly in the Arctic. Iron released from melting ice increases
phytoplankton production in spring and summer and shifts phytoplankton
community composition in the Southern Ocean. Results for the period of 1998
to 2007 indicate that a reduction of sea ice in the Southern Ocean will have
a negative influence on phytoplankton production. Iron transport by sea ice
appears to be an important process bringing iron to the central Arctic. The
impact of ice to ocean iron fluxes on marine ecosystems is negligible in the
current Arctic Ocean, as iron is not typically the growth-limiting nutrient.
However, it may become a more important factor in the future, particularly in
the central Arctic, as iron concentrations will decrease with declining sea
ice cover and transport
In vitro characteristics and in vivo platelet quality of whole blood treated with riboflavin and UVA/UVB light and stored for 24 hours at room temperature
Background
There is a global increase in whole blood usage and at the same time, emerging pathogens give cause for pathogen reduction technology (PRT). The Mirasol PRT has shown promising results for plasma and platelet concentrate products. Treatment of whole blood with subsequent platelet survival and recovery analysis would be of global value.
Study Design and Methods
A two-arm, open-label laboratory study was performed with 40 whole blood collections in four groups: non-leukoreduced non-PRT-treated, non-leukoreduced PRT-treated, leukoreduced non-PRT-treated, and leukoreduced PRT-treated.
Leukoreduction and/or PRT-treatment was performed on the day of collection, then all WB units were stored at room temperature for 24âh. Sampling was performed after hold-time and after 24-h storage in RT. If PRT-treatment or leukoreduction, samples were also taken subsequently after treatment.
Thirteen healthy volunteer blood donors completed the in vivo study per protocol. All WB units were non-leukoreduced and PRT-treated. Radioactive labeling of platelets from RT-stored, PRT-treated whole blood, sampling of subjects, recovery, and survival calculations were performed according to the Biomedical Excellence for Safer Transfusion Collaborative protocol.
Results
In vitro characteristics show that PRT-treatment leads to increased levels of hemolysis, potassium, and lactate, while there are decreased levels of glucose, FVIII, and fibrinogen after 24âh of storage. All values are within requirements for WB.
In vivo recovery and survival of platelets were 85.4% and 81.3% of untreated fresh control, respectively.
Conclusions
PRT-treatment moderately reduces whole blood quality but is well within the limits of international guidelines. Recovery and survival of platelets are satisfactory after Mirasol treatment.publishedVersio
The role of alcohol in constructing gender & class identities among young women in the age of social media
Research suggests young women view drinking as a pleasurable aspect of their social lives but that they face challenges in engaging in a traditionally âmasculineâ behaviour whilst maintaining a desirable âfemininityâ. Social network sites such as Facebook make socialising visible to a wide audience. This paper explores how young people discuss young womenâs drinking practices, and how young women construct their identities through alcohol consumption and its display on social media. We conducted 21 friendship-based focus groups (both mixed and single sex) with young adults aged 18â29 years and 13 individual interviews with a subset of focus group respondents centred on their Facebook practices. We recruited a purposive sample in Glasgow, Scotland (UK) which included âmiddle classâ (defined as students and those in professional jobs) and âworking classâ respondents (employed in manual/service sector jobs), who participated in a range of venues in the night time economy. Young womenâs discussions revealed a difficult âbalancing actâ between demonstrating an âup for itâ sexy (but not too sexy) femininity through their drinking and appearance, while still retaining control and respectability. This âbalancing actâ was particularly precarious for working class women, who appeared to be judged more harshly than middle class women both online and offline. While a gendered double standard around appearance and alcohol consumption is not new, a wider online audience can now observe and comment on how women look and behave. Social structures such as gender and social class remain central to the construction of identity both online and offline
Best practice in alcohol ignition interlock schemes
Australiaâs National Road Safety Strategy 2011-2020 proposes greater use of alcohol ignition interlocks. To inform a potential expansion of interlock use, an international literature review examined the influence of mandatory versus voluntary alcohol ignition interlock schemes (AIS) in offendersâ subsequent driving and broader rehabilitation, and interlocks as preventative measures in occupational driving contexts. Additionally, the review documented AIS operational effectiveness in relation to first offenders versus repeat offenders, timing of program admittance and exit, program monitoring, participant support programs and problems experienced in AIS implementation. Evaluations of road safety effectiveness for AIS in Canada, USA, Sweden and Australia were also studied. The literature review yielded a substantial list of considered best practice components of effective AIS, ranging from the various broad contexts where interlock use can be usefully encouraged or mandated, down to specific operational considerations. Identifying best practice components affords assistance to any efforts to progress the National Strategyâs vision for the future deployment of interlocks.Bailey, T.J., Lindsay, V.L. & Royals, J.http://acrs.org.au/events/acrs-past-conferences/2013-a-safe-system-the-road-safety-discussion
PrimPol bypasses UV photoproducts during eukaryotic chromosomal DNA replication
DNA damage can stall the DNA replication machinery, leading to genomic instability. Thus, numerous mechanisms exist to complete genome duplication in the absence of a pristine DNA template, but identification of the enzymes involved remains incomplete. Here, we establish that Primase-Polymerase (PrimPol; CCDC111), an archaeal-eukaryotic primase (AEP) in eukaryotic cells, is involved in chromosomal DNA replication. PrimPol is required for replication fork progression on ultraviolet (UV) lightdamaged DNA templates, possibly mediated by its ability to catalyze translesion synthesis (TLS) of these lesions. This PrimPol UV lesion bypass pathway is not epistatic with the Pol h-dependent pathway and, as a consequence, protects xeroderma pigmentosum variant (XP-V) patient cells from UV-induced cytotoxicity. In addition, we establish that PrimPol is also required for efficient replication fork progression during an unperturbed S phase. These and other findings indicate that PrimPol is an important player in replication fork progression in eukaryotic cells
MEIS investigations of surface structure
The early work of the FOM-AMOLF group in Amsterdam clearly demonstrated the potential of medium energy ion scattering (MEIS), typically using 100 keV H+ incident ions, to investigate the structure of surfaces, but most current applications of the method are focussed on near-surface compositional studies of non-crystalline films. However, the key strengths of the MEIS technique, notably the use of blocking curves in double-alignment experiments and absolute yield measurements, are extremely effective in providing detailed near-surface structural information for a wide range of crystalline materials. This potential and the underlying methodology, is illustrated through examples of applications to the study of layer-dependent composition and structure in alloy surfaces, in studies of the surface crystallography of an oxide surface (rutile TiO2(1 1 0)) and in investigations of complex adsorbate-induced reconstruction of metal surfaces, including the pseudo-(1 0 0) reconstruction of Cu(1 1 1) induced by adsorption of atomic N and molecular methylthiolate (CH3Sâ). In addition to the use of calibrated blocking curves, the use of the detailed spectral shape of the surface peak in the scattered ion energy spectra, as a means of providing single-atomic layer resolution of the surface structure, is also discussed
The phase diagrams of KCaF3 and NaMgF3 by ab initio simulations
ABF3 compounds have been found to make valuable low-pressure analogues for high-pressure silicate phases that are present in the Earthâs deep interior and that may also occur in the interiors of exoplanets. The phase diagrams of two of these materials, KCaF3 and NaMgF3, have been investigated in detail by static ab initio computer simulations based on density functional theory. Six ABF3 polymorphs were considered, as follows: the orthorhombic perovskite structure (GdFeO3-type; space group Pbnm); the orthorhombic CaIrO3 structure (Cmcm; commonly referred to as the âpost-perovskiteâ structure); the orthorhombic Sb2S3 and La2S3 structures (both Pmcn); the hexagonal structure previously suggested in computer simulations of NaMgF3 (P63/mmc); the monoclinic structure found to be intermediate between the perovskite and CaIrO3 structures in CaRhO3 (P21/m). Volumetric and axial equations of state of all phases considered are presented. For KCaF3, as expected, the perovskite phase is shown to be the most thermodynamically stable at atmospheric pressure. With increasing pressure, the relative stability of the KCaF3 phases then follows the sequence: perovskite â La2S3 structure â Sb2S3 structure â P63/mmc structure; the CaIrO3 structure is never the most stable form. Above about 2.6 GPa, however, none of the KCaF3 polymorphs are stable with respect to dissociation into KF and CaF2. The possibility that high-pressure KCaF3 polymorphs might exist metastably at 300 K, or might be stabilised by chemical substitution so as to occur within the standard operating range of a multi-anvil press, is briefly discussed. For NaMgF3, the transitions to the high-pressure phases occur at pressures outside the normal range of a multi-anvil press. Two different sequences of transitions had previously been suggested from computer simulations. With increasing pressure, we find that the relative stability of the NaMgF3 phases follows the sequence: perovskite â CaIrO3 structure â Sb2S3 structure â P63/mmc structure. However, only the perovskite and CaIrO3 structures are stable with respect to dissociation into NaF and MgF2
Catchment-scale biogeography of riverine bacterioplankton
Lotic ecosystems such as rivers and streams are unique in that they represent a continuum of both space and time during the transition from headwaters to the river mouth. As microbes have very different controls over their ecology, distribution and dispersion compared with macrobiota, we wished to explore biogeographical patterns within a river catchment and uncover the major drivers structuring bacterioplankton communities. Water samples collected across the River Thames Basin, UK, covering the transition from headwater tributaries to the lower reaches of the main river channel were characterised using 16S rRNA gene pyrosequencing. This approach revealed an ecological succession in the bacterial community composition along the river continuum, moving from a community dominated by Bacteroidetes in the headwaters to Actinobacteria-dominated downstream. Location of the sampling point in the river network (measured as the cumulative water channel distance upstream) was found to be the most predictive spatial feature; inferring that ecological processes pertaining to temporal community succession are of prime importance in driving the assemblages of riverine bacterioplankton communities. A decrease in bacterial activity rates and an increase in the abundance of low nucleic acid bacteria relative to high nucleic acid bacteria were found to correspond with these downstream changes in community structure, suggesting corresponding functional changes. Our findings show that bacterial communities across the Thames basin exhibit an ecological succession along the river continuum, and that this is primarily driven by water residence time rather than the physiochemical status of the river
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