1,091 research outputs found
A new phylogeny of Stegosauria (Dinosauria, Ornithischia)
The stegosaurs are some of the most easily recognisable dinosaurs, but they are surprisingly rare as fossils. Consequently much remains unknown about their palaeobiology, and every new stegosaurian find contr ibutes to understanding the evolution of the clade. Since the last attempt to examine the evolutionary relationships of Stegosauria, new specimens have come to light, including the most complete individual of Stegosaurus ever found, new taxa have been desc ribed and, perhaps most importantly, new methods for analysis of cladistic datasets have been produced. In the light of these new data and technological advances, the phylogenetic relationships of the stegosaurs and basal armoured dinosaurs are investigate d. The inclusion of continuous data results in much better resolution than was previously obtained, and the resulting single most parsimonious tree supports re - erection of the genera Miragaia and Hesperosaurus , which had previously been synonymized with Dacentrurus and Stegosaurus respectively. The recently described genus Alcovasaurus is resolved as a basal thyreophoran, but this is likely to be due to a combination of a very high degree of missing data and the questionable ontogenetic stage of the speci men. Examination of the effects of continuous data on the analysis suggest that while it contains a phylogenetic signal congruent with that of discrete data and provides better resolution than discrete data alone, it can affect t opologies in unpredictable ways, particularly in areas of the tree where there are large amounts of missing data. The phylogeny presented here will form the basis for future work on the palaeobiology of the plated dinosaurs
Contrasting arbuscular mycorrhizal responses of vascular and non-vascular plants to a simulated Palaeozoic CO2 decline
Ocean Acidification Affects Prey Detection by a Predatory Reef Fish
Changes in olfactory-mediated behaviour caused by elevated CO2 levels in the ocean could affect recruitment to reef fish populations because larval fish become more vulnerable to predation. However, it is currently unclear how elevated CO2 will impact the other key part of the predator-prey interaction – the predators. We investigated the effects of elevated CO2 and reduced pH on olfactory preferences, activity levels and feeding behaviour of a common coral reef meso-predator, the brown dottyback (Pseudochromis fuscus). Predators were exposed to either current-day CO2 levels or one of two elevated CO2 levels (∼600 µatm or ∼950 µatm) that may occur by 2100 according to climate change predictions. Exposure to elevated CO2 and reduced pH caused a shift from preference to avoidance of the smell of injured prey, with CO2 treated predators spending approximately 20% less time in a water stream containing prey odour compared with controls. Furthermore, activity levels of fish was higher in the high CO2 treatment and feeding activity was lower for fish in the mid CO2 treatment; indicating that future conditions may potentially reduce the ability of the fish to respond rapidly to fluctuations in food availability. Elevated activity levels of predators in the high CO2 treatment, however, may compensate for reduced olfactory ability, as greater movement facilitated visual detection of food. Our findings show that, at least for the species tested to date, both parties in the predator-prey relationship may be affected by ocean acidification. Although impairment of olfactory-mediated behaviour of predators might reduce the risk of predation for larval fishes, the magnitude of the observed effects of elevated CO2 acidification appear to be more dramatic for prey compared to predators. Thus, it is unlikely that the altered behaviour of predators is sufficient to fully compensate for the effects of ocean acidification on prey mortality
Evaluation of a manualised speech and language therapy programme for children with social communication disorder: the SCIP feasibility study
Background: Children with Social (Pragmatic) Communication Disorder (SPCD) have long-3 term needs in using and processing social language and have a high risk of later mental health difficulties. A manualised speech and language therapy programme, the Social Communication Intervention Programme (SCIP) provides therapy content for SPCD. A feasibility study is required to derive more precise estimates of key parameters for a future trial of SCIP.
Aims: To assess the feasibility of conducting a substantive randomized controlled trial of SCIP for children with SPCD.
Methods: A questionnaire was distributed to paediatric speech and language therapists in England. Survey questions addressed number of eligible children, routine intervention provision and trial recruitment factors. In the second phase, a single-arm intervention feasibility study was completed. 15 speech and language practitioners identified 24 children aged 5-11 years with SPCD. Practitioners received training/supervision to deliver 20 SCIP therapy sessions to each child. At Time 1 parents of participating children provided three communication goals; expected steps in each goal were defined. After intervention, parents and practitioners independently rated each goal compared to baseline ability. Two research practitioners compared parent post-intervention commentaries with outcome scores to derive guidance about clinical significance. All practitioners recorded audio commentaries on therapy experiences. Post-intervention interviews were conducted with 6 practitioners and 6 parents. An expert panel completed a Delphi consultation on trial design.
Results: Routine practice for SPCD varies widely. Children tend to be embedded in autism provision. Participation in a future trial was well-supported, provided resources are available to services. Outcomes analysis indicated all children except one made some progress on parent ratings; all children made progress on practitioner ratings. A power analysis for a future trial was carried out using current outcome measure as putative primary endpoint. Practitioners’ audio-diaries provided suggestions for training and adaption in a future trial. Outcomes and therapy methods were acceptable to practitioners and parents.
Conclusions: The feasibility study evaluated a novel outcome measure of social communication skills in SPCD. A power calculation indicated a feasible framework for a trial within a realistic period of time. Recommendations for recruitment methods, adaptation of manual and training were 6 supported by practitioners and an expert panel
Effects of Salt Stress on Three Ecologically Distinct Plantago Species
Comparative studies on the responses to salt stress of taxonomically related taxa should
help to elucidate relevant mechanisms of stress tolerance in plants. We have applied this
strategy to three Plantago species adapted to different natural habitats, P. crassifolia and P.
coronopus both halophytes and P. major, considered as salt-sensitive since it is never
found in natural saline habitats. Growth inhibition measurements in controlled salt treatments
indicated, however, that P. major is quite resistant to salt stress, although less than
its halophytic congeners. The contents of monovalent ions and specific osmolytes were
determined in plant leaves after four-week salt treatments. Salt-treated plants of the three
taxa accumulated Na+ and Cl- in response to increasing external NaCl concentrations, to a
lesser extent in P. major than in the halophytes; the latter species also showed higher ion
contents in the non-stressed plants. In the halophytes, K+ concentration decreased at moderate
salinity levels, to increase again under high salt conditions, whereas in P. major K+
contents were reduced only above 400 mM NaCl. Sorbitol contents augmented in all plants,
roughly in parallel with increasing salinity, but the relative increments and the absolute values
reached did not differ much in the three taxa. On the contrary, a strong (relative) accumulation
of proline in response to high salt concentrations (600 800 mM NaCl) was
observed in the halophytes, but not in P. major. These results indicate that the responses to
salt stress triggered specifically in the halophytes, and therefore the most relevant for tolerance
in the genus Plantago are: a higher efficiency in the transport of toxic ions to the
leaves, the capacity to use inorganic ions as osmotica, even under low salinity conditions,
and the activation, in response to very high salt concentrations, of proline accumulation and
K+ transport to the leaves of the plants.MAH was a recipient of an Erasmus Mundus pre-doctoral scholarship financed by the European Commission (Welcome Consortium). AP acknowledges the Erasmus mobility programme for funding her stay in Valencia to carry out her Master Thesis.Al Hassan, M.; Pacurar, AM.; López Gresa, MP.; Donat Torres, MDP.; Llinares Palacios, JV.; Boscaiu Neagu, MT.; Vicente Meana, Ó. (2016). Effects of Salt Stress on Three Ecologically Distinct Plantago Species. PLoS ONE. 11(8):1-21. doi:10.1371/journal.pone.0160236S12111
Evidence for an excess of B -> D(*) Tau Nu decays
Based on the full BaBar data sample, we report improved measurements of the
ratios R(D(*)) = B(B -> D(*) Tau Nu)/B(B -> D(*) l Nu), where l is either e or
mu. These ratios are sensitive to new physics contributions in the form of a
charged Higgs boson. We measure R(D) = 0.440 +- 0.058 +- 0.042 and R(D*) =
0.332 +- 0.024 +- 0.018, which exceed the Standard Model expectations by 2.0
sigma and 2.7 sigma, respectively. Taken together, our results disagree with
these expectations at the 3.4 sigma level. This excess cannot be explained by a
charged Higgs boson in the type II two-Higgs-doublet model. We also report the
observation of the decay B -> D Tau Nu, with a significance of 6.8 sigma.Comment: Expanded section on systematics, text corrections, improved the
format of Figure 2 and included the effect of the change of the Tau
polarization due to the charged Higg
Search for the decay modes D^0 → e^+e^-, D^0 → μ^+μ^-, and D^0 → e^±μ∓
We present searches for the rare decay modes D^0→e^+e^-, D^0→μ^+μ^-, and D^0→e^±μ^∓ in continuum e^+e^-→cc events recorded by the BABAR detector in a data sample that corresponds to an integrated luminosity of 468 fb^(-1). These decays are highly Glashow–Iliopoulos–Maiani suppressed but may be enhanced in several extensions of the standard model. Our observed event yields are consistent with the expected backgrounds. An excess is seen in the D^0→μ^+μ^- channel, although the observed yield is consistent with an upward background fluctuation at the 5% level. Using the Feldman–Cousins method, we set the following 90% confidence level intervals on the branching fractions: B(D^0→e^+e^-)<1.7×10^(-7), B(D^0→μ^+μ^-) within [0.6,8.1]×10^(-7), and B(D^0→e^±μ^∓)<3.3×10^(-7)
Breastfeeding, Maternal Education and Cognitive Function: A Prospective Study in Twins
The effect of breastfeeding on cognitive abilities is examined in the offspring of highly educated women and compared to the effects in women with low or middle educational attainment. All offspring consisted of 12-year old mono- or dizygotic twins and this made it possible to study the effect of breastfeeding on mean cognition scores as well as the moderating effects of breastfeeding on the heritability of variation in cognition. Information on breastfeeding and cognitive ability was available for 6,569 children. Breastfeeding status was prospectively assessed in the first years after birth of the children. Maternal education is positively associated with performance on a standardized test for cognitive ability in offspring. A significant effect of breastfeeding on cognition was also observed. The effect was similar for offspring with mothers with a high, middle, and low educational level. Breast-fed children of highly educated mothers score on average 7.6 point higher on a standardized test of cognitive abilities (CITO test; range 500–550; effects size = .936) than formula-fed children of mothers with a low education. Individual differences in cognition scores are largely accounted for by additive genetic factors (80%) and breastfeeding does not modify the effect of genetic factors in any of the three strata of maternal education. Heritability was slightly lower in children with a mother with a middle-level education
A search for the decay modes B+/- to h+/- tau l
We present a search for the lepton flavor violating decay modes B+/- to h+/-
tau l (h= K,pi; l= e,mu) using the BaBar data sample, which corresponds to 472
million BBbar pairs. The search uses events where one B meson is fully
reconstructed in one of several hadronic final states. Using the momenta of the
reconstructed B, h, and l candidates, we are able to fully determine the tau
four-momentum. The resulting tau candidate mass is our main discriminant
against combinatorial background. We see no evidence for B+/- to h+/- tau l
decays and set a 90% confidence level upper limit on each branching fraction at
the level of a few times 10^-5.Comment: 15 pages, 7 figures, submitted to Phys. Rev.
Measurement of the branching fraction and CP content for the decay B(0) -> D(*+)D(*-)
This is the pre-print version of the Article. The official published version can be accessed from the links below. Copyright @ 2002 APS.We report a measurement of the branching fraction of the decay B0→D*+D*- and of the CP-odd component of its final state using the BABAR detector. With data corresponding to an integrated luminosity of 20.4 fb-1 collected at the Υ(4S) resonance during 1999–2000, we have reconstructed 38 candidate signal events in the mode B0→D*+D*- with an estimated background of 6.2±0.5 events. From these events, we determine the branching fraction to be B(B0→D*+D*-)=[8.3±1.6(stat)±1.2(syst)]×10-4. The measured CP-odd fraction of the final state is 0.22±0.18(stat)±0.03(syst).This work is supported by DOE and NSF (USA), NSERC (Canada), IHEP (China), CEA and CNRS-IN2P3 (France), BMBF (Germany), INFN (Italy), NFR (Norway), MIST (Russia), and PPARC (United Kingdom). Individuals have received support from the A.P. Sloan Foundation, Research Corporation, and Alexander von Humboldt Foundation
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