59 research outputs found

    Outcomes of a Comparison Study into a Group-Based Infant Parenting Programme

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    This paper reports on a quantitative evaluation of a group-based programme designed to promote parent-infant attachment and child development. Whilst group-based parenting programmes are recommended for treating and preventing conduct disorder in older children, there is, as yet, little evidence as to whether they have a positive effect on very young children and their carers’. Recent UK Government initiatives to support families and improve parenting skills in the first 2 years of children’s lives have increased the demand for the delivery and evaluation of community-based programmes. Eighty mother–child dyads were recruited from nine areas to intervention (n = 54) and control condition (n = 26). Baseline measures were collected in the children’s home when the infants were on average 3-months-old, and follow-up measures were collected 6 months post-baseline (N = 63). Mothers’ positive play behaviours were independently coded from video recordings taken in the home. Other measures included self-reported maternal confidence and mental well-being, assessed infant development and home environment. Socio-demographic data was collected once at baseline. After controlling for baseline scores, control mothers were observed to be significantly less sensitive during play with their baby at the 6 months follow-up with a significant increase in confidence. No differences were found between the groups on the other measures. This paper provides limited evidence for the effectiveness of the Incredible Years Parents and Babies group-based programme delivered in the first year of life. Further evaluation, particularly with parents at increased risk of poorer outcomes is needed to confirm and extend these results

    Climatic and topographic changes since the Miocene influenced the diversification and biogeography of the tent tortoise (Psammobates tentorius) species complex in Southern Africa

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    Background: Climatic and topographic changes function as key drivers in shaping genetic structure and cladogenic radiation in many organisms. Southern Africa has an exceptionally diverse tortoise fauna, harbouring one-third of the world’s tortoise genera. The distribution of Psammobates tentorius (Kuhl, 1820) covers two of the 25 biodiversity hotspots in the world, the Succulent Karoo and Cape Floristic Region. The highly diverged P. tentorius represents an excellent model species for exploring biogeographic and radiation patterns of reptiles in Southern Africa. Results: We investigated genetic structure and radiation patterns against temporal and spatial dimensions since the Miocene in the Psammobates tentorius species complex, using multiple types of DNA markers and niche modelling analyses. Cladogenesis in P. tentorius started in the late Miocene (11.63–5.33 Ma) when populations dispersed from north to south to form two geographically isolated groups. The northern group diverged into a clade north of the Orange River (OR), followed by the splitting of the group south of the OR into a western and an interior clade. The latter divergence corresponded to the intensifcation of the cold Benguela current, which caused western aridifcation and rainfall seasonality. In the south, tectonic uplift and subsequent exhumation, together with climatic fuctuations seemed responsible for radiations among the four southern clades since the late Miocene. We found that each clade occurred in a habitat shaped by diferent climatic parameters, and that the niches difered substantially among the clades of the northern group but were similar among clades of the southern group. Conclusion: Climatic shifts, and biome and geographic changes were possibly the three major driving forces shaping cladogenesis and genetic structure in Southern African tortoise species. Our results revealed that the cladogenesis of the P. tentorius species complex was probably shaped by environmental cooling, biome shifts and topographic uplift in Southern Africa since the late Miocene. The Last Glacial Maximum (LGM) may have impacted the distribution of P. tentorius substantially. We found the taxonomic diversify of the P. tentorius species complex to be highest in the Greater Cape Floristic Region. All seven clades discovered warrant conservation attention, particularly Ptt-B–Ptr, Ptt-A and Pv-

    Classifying chimpanzee (Pan troglodytes) landscapes across large scale environmental gradients in Africa

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    Primates are sometimes categorized in terms of their habitat. Although such categorization can be over-simplistic, there are scientific benefits from the clarity and consistency that habitat categorization can bring. Chimpanzees (Pan troglodytes) inhabit various environments, but researchers often refer to ‘forest’ or ‘savanna’ chimpanzees. Despite the wide use of this forest-savanna distinction, clear definitions of these landscapes for chimpanzees, based on environmental variables at study sites or determined in relation to existing bioclimatic classifications, are lacking. The robustness of the forest-savanna distinction thus remains to be assessed. We review 43 chimpanzee study sites to assess how the landscape classifications of researchers fit with the environmental characteristics of study sites and with three bioclimatic classifications. We use scatterplots and Principal Components 15 Analysis to assess the distribution of chimpanzee field sites along gradients of environmental 16 variables (temperature, rainfall, precipitation seasonality, forest cover and satellite-derived 17 Hansen tree cover). This revealed an environmental continuum of chimpanzee study sites 18 from savanna to dense forest, with a rarely acknowledged forest mosaic category in between, 19 but with no natural separation into these three classes and inconsistencies with the bioclimatic 20 classifications assessed. The current forest–savanna dichotomy therefore masks a progression 21 of environmental adaptation for chimpanzees, and we propose that recognizing an additional, 22 intermediate ‘forest mosaic’ category is more meaningful than focusing on the ends of this 23 environmental gradient only. Future studies should acknowledge this habitat continuum, place their study sites on the forest–savanna gradient, and include detailed environmental data to support further attempts at quantification

    Measurement of the electron reconstruction efficiency at LHCb

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    The single electron track-reconstruction efficiency is calibrated using a sample corresponding to 1.3 fb−1 of pp collision data recorded with the LHCb detector in 2017. This measurement exploits B+→ J/ψ(e+e−)K+ decays, where one of the electrons is fully reconstructed and paired with the kaon, while the other electron is reconstructed using only the information of the vertex detector. Despite this partial reconstruction, kinematic and geometric constraints allow the B meson mass to be reconstructed and the signal to be well separated from backgrounds. This in turn allows the electron reconstruction efficiency to be measured by matching the partial track segment found in the vertex detector to tracks found by LHCb's regular reconstruction algorithms. The agreement between data and simulation is evaluated, and corrections are derived for simulated electrons in bins of kinematics. These correction factors allow LHCb to measure branching fractions involving single electrons with a systematic uncertainty below 1%

    Agriculture

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    Mechanochemical synthesis and electrochemical properties of nanostructured electrode materials for Li ion batteries

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    We focus on the synthesis by ball milling and on the electrochemical characterization of nanocrystalline bimetallic and composite materials to be employed as anodes in Li ion batteries. Ni 3Sn 4 and Ni 3Sn 2 based compounds were obtained by ball milling of three different Ni-Sn mixtures. The properties of the resulting anodes for Li ion batteries were evaluated as a function of composition. Moreover, a biphasic system is presented, with CoSn 2 and CoSn type structures, arising from the synthesis of the Sn 31Co 28C 41 composition. When cycled in a Li cell, this material showed a high reversible specific capacity, about 450 mA h g -1, and a very good electrochemical and structural stability, making it of interest for application purposes. © 2008 Springer-Verlag
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