71 research outputs found
A taxonomic revision of Capnophyllum (Apiaceae: Apioideae)
AbstractThe Cape endemic genus Capnophyllum Gaertn. is revised. As a result of valuable recent collections and extensive fieldwork, this hitherto neglected genus was found to comprise four annual species, two of which are newly described, namely C. lutzeyeri Magee and B.-E.van Wyk, and C. macrocarpum Magee and B.-E.van Wyk. The four species are distinguished from one another by their fruit morphology (relative length of the styles, the shape and position of the stylopodium, fruit size, surface sculpturing, and the presence or absence of a sterile apical portion) and fruit anatomy (marginal wings slightly or prominently involute and secondary ribs present or absent). A comprehensive key to the species, their complete nomenclature and typification, together with complete descriptions and known geographical distributions for all the species are presented and illustrated
Spontaneous CP Violating Phase as the Phase in PMNS Matrix
We study the possibility of identifying the CP violating phases in the PMNS
mixing matrix in the lepton sector and also that in the CKM mixing matrix in
the quark sector with the phase responsible for the spontaneous CP violation in
the Higgs potential, and some implications. Since the phase in the CKM mixing
matrix is determined by experimental data, the phase in the lepton sector is
therefore also fixed. The mass matrix for neutrinos is constrained leading to
constraints on the Jarlskog CP violating parameter , and the effective mass
for neutrinoless double beta decay. The Yukawa couplings are
also constrained. Different ways of identifying the phases have different
predictions for and . Future
experimental data can be used to distinguish different models.Comment: 16 pages, 3 figure
QRAP: a numerical code for projected (Q)uasi-particle (RA)ndom (P)hase approximation
A computer code for quasiparticle random phase approximation-QRPA and
projected quasiparticle random phase approximation-PQRPA models of nuclear
structure is explained in details. An important application of the code
consists in evaluating nuclear matrix elements involved in neutrino-nucleus
reactions. As an example, cross section for 56Fe and 12C are calculated and the
code output is explained. The application to other nuclei and the description
of other nuclear and weak decay processes is also discussed.Comment: 15 pages, 2 figures, accepted for publication in Computer Physics
Communication
Uniaxial negative thermal expansion and metallophilicity in Cu3[Co(CN)6]
We report the synthesis and structural characterisation of the molecular framework copper(I)hexacyanocobaltate(III), Cu3[Co(CN)6], which we ïŹnd to be isostructural to H3[Co(CN)6] and the colossalnegative thermal expansion material Ag3[Co(CN)6]. Using synchrotron X-ray powder diïŹraction measurements,we ïŹnd strong positive and negative thermal expansion behaviour respectively perpendicular and parallel to thetrigonal crystal axis:α= 25.4(5) MKaâ1andα= â 43.5(8) MKcâ1. These opposing eïŹects collectively result in avolume expansivityα= 7.4(11) MKVâ1that is remarkably small for an anisotropic molecular framework. Thisthermal response is discussed in the context of the behaviour of the analogous H- and Ag-containing systems.We make use of density-functional theory with many-body dispersion interactions (DFT + MBD) todemonstrate that Cu+âŠCu+metallophilic (âcuprophilicâ) interactions are signiïŹcantly weaker in Cu3[Co(CN)6]than Ag+âŠAg+interactions in Ag3[Co(CN)6], but that this lowering of energy scale counterintuitively translatesto a more moderateârather than enhancedâdegree of structural ïŹexibility. The same conclusion is drawn fromconsideration of a simple GULP model, which we also present here. Our results demonstrate that stronginteractions can actually be exploited in the design of ultra-responsive materials if those interactions are set upto act in tension
Neutrino oscillation studies with IceCube-DeepCore
AbstractIceCube, a gigaton-scale neutrino detector located at the South Pole, was primarily designed to search for astrophysical neutrinos with energies of PeV and higher. This goal has been achieved with the detection of the highest energy neutrinos to date. At the other end of the energy spectrum, the DeepCore extension lowers the energy threshold of the detector to approximately 10 GeV and opens the door for oscillation studies using atmospheric neutrinos. An analysis of the disappearance of these neutrinos has been completed, with the results produced being complementary with dedicated oscillation experiments. Following a review of the detector principle and performance, the method used to make these calculations, as well as the results, is detailed. Finally, the future prospects of IceCube-DeepCore and the next generation of neutrino experiments at the South Pole (IceCube-Gen2, specifically the PINGU sub-detector) are briefly discussed
Physical activity, diet and BMI in children aged 6â8 years : a cross-sectional analysis
Objective To assess relationships between current physical activity (PA), dietary intake and body mass index (BMI) in English children. Longitudinal birth cohort study in northeast England, cross-sectional analysis. Participants 425 children (41% of the original cohort) aged 6â8â
years (49% boys). Main outcome measures PA over 7â
days was measured objectively by an accelerometer; three categories of PA were created: âactiveâ â„60â
min/day moderate-to-vigorous-intensity PA (MVPA); âmoderately activeâ 30â59â
min/day MVPA; âinactiveâ <30â
min/day MVPA. Dietary intake over 4â
days was measured using a prospective dietary assessment tool which incorporated elements of the food diary and food frequency methods. Three diet categories were created: âhealthyâ, âunhealthyâ and âmixedâ, according to the number of portions of different foods consumed. Adherence to the â5-a-dayâ recommendations for portions of fruit and vegetables was also assessed. Children were classified as âhealthy weightâ or âoverweight or obeseâ (OW/OB) according to International Obesity Taskforce cutpoints for BMI. Associations between weight status and PA/diet categories were analysed using logistic regression. Few children met the UK-recommended guidelines for either MVPA or fruit and vegetable intake, with just 7% meeting the recommended amount of MVPA of 60â
min/day, and 3% meeting the 5-a-day fruit and vegetable recommendation. Higher PA was associated with a lower OR for OW/OB in boys only (0.20, 95% CI 0.04 to 0.88). There was no association detected between dietary intake and OW/OB in either sex. Increasing MVPA may help to reduce OW/OB in boys; however, more research is required to examine this relationship in girls. Children are not meeting the UK guidelines for diet and PA, and more needs to be done to improve this situation
When do mothers think their child is overweight?
Objective: To quantify how overweight children have to be for their mothers to classify them as overweight and to express concern about future overweight, and to investigate the adiposity cues in children that mothers respond to. Design: Cross-sectional. Subjects: A total of 531 children from the Gateshead Millennium Study cohort at 6-8 years and their mothers. Measurements: In the mother: responses to two questions concerning the child's adiposity; height; weight; educational qualifications; and economic status. In the child: height; weight; waist circumference; skinfold thicknesses; bioelectrical impedance; and bone frame measurements. Results: The body mass index (BMI) at which half the mothers classify their child as overweight was 21.3 (in the obese range for children of this age). The BMI at which half the mothers were concerned about their child becoming overweight in the future was 17.1 (below the overweight range). Waist circumference and skinfolds contributed most to mothers' responses. Although BMI and fat scores were important predictors individually, they did not contribute independently once waist circumference and skinfolds (their most visible manifestations) were included in the regression equations. Mothers were less likely to classify girls as overweight. Mothers with higher BMIs were less likely to classify their child as overweight, but were more likely to be concerned about future overweight. Conclusion: Health promotion efforts directed at parents of young primary school children might better capitalise on their concern about future overweight in their child than on current weight status, and focus on mothers' response to more visible characteristics than the BMI. International Journal of Obesity (2011) 35, 510-516; doi: 10.1038/ijo.2010.260; published online 11 January 201
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