3,119 research outputs found
Primordia initiation of mushroom (Agaricus bisporus) strains on axenic casing materials
The mushroom (Agaricus bisporus) has a
requirement for a ‘‘casing layer’’ that has specific
physical, chemical and microbiological properties
which stimulate and promote the initiation of primordia.
Some of these primordia then may develop
further into sporophores, involving differentiation of
tissue. Wild and commercial strains of A. bisporus
were cultured in axenic and nonaxenic microcosms,
using a rye grain substrate covered by a range of organic
and inorganic casing materials. In axenic culture,
A. bisporus (commercial strain A15) was capable
of producing primordia and mature sporophores on
charcoal (wood and activated), anthracite coal, lignite
and zeolite, but not on bark, coir, peat, rockwool,
silica or vermiculite. Of six strains tested, only
the developmental variant mutant, B430, produced
rudimentary primordia on axenic peat-based casing
material. However, none of these rudimentary primordia
developed differentiated tissues or beyond 4
mm diameter, either on axenic casing material in the
microcosms or in larger-scale culture. In larger-scale,
nonaxenic culture, strain B430 produced severely
malformed but mature sporophores in similar numbers
to those of other strains. Typically, 3–6% of primordia
developed into mature sporophores, but significant
differences in this proportion, as well as in
the numbers of primordia produced, were recorded
between 12 A. bisporus strains
Transitioning in higher education: An exploration of psychological and contextual factors affecting student satisfaction
© 2017 UCU. In view of recent changes in the higher education sector, such as increased tuition fees, a greater focus has been placed on widening participation initiatives and monitoring student satisfaction. The aims of the current study were twofold: (1) to explore whether pre-entry programmes foster successful transition to higher education, and (2) to examine longitudinally the factors associated with course satisfaction. Eighty-eight first-year psychology students completed a questionnaire measuring academic self-efficacy, social identity and student satisfaction at the start (Time 1, November 2015) and end (Time 2, March 2016) of the academic year. Findings indicated that students who participated in a pre-entry programme reported higher academic self-efficacy and satisfaction compared to typical route students. Moreover, academic self-efficacy predicted student satisfaction at the start of the academic year, whereas in-group affect (a facet of social identity) predicted this at the end of the academic year. The current findings indicate that pre-entry programmes may have a positive impact on students’ sense of academic self-efficacy. On a more general level, the findings also suggest that academic self-efficacy and social identity may be key indicators of student satisfaction. This highlights the complexities of the concept of ‘student satisfaction’, and demonstrates the utility of examining multiple factors relating to student satisfaction across different time points
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General Electric Atomic Power Equipment Department Report GEAP-4566
Quarterly report describing progress on the EVESR Nuclear Superheat Fuel Development Project
Effect of Wavefunction Renormalisation in N-Flavour Qed3 at Finite Temperature
A recent study of dynamical chiral symmetry breaking in N-flavour QED at
finite temperature is extended to include the effect of fermion wavefunction
renormalisation in the Schwinger-Dyson equations. The simple ``zero-frequency''
truncation previously used is found to lead to unphysical results, especially
as . A modified set of equations is proposed, whose solutions behave
in a way which is qualitatively similar to the solutions of Pennington et
al. [5-8] who have made extensive studies of the effect of wavefunction
renormalisation in this context, and who concluded that there was no critical
(at T=0) above which chiral symmetry was restored. In contrast, we find
that our modified equations predict a critical at , and an
phase diagram very similar to the earlier study neglecting wavefunction
renormalisation. The reason for the difference is traced to the different
infrared behaviour of the vacuum polarisation at and at .Comment: 17 pages + 13 figures (available upon request), Oxford preprint
OUTP-93-30P, IFUNAM preprint FT94-39, LaTe
String Theory and Water Waves
We uncover a remarkable role that an infinite hierarchy of non-linear
differential equations plays in organizing and connecting certain {hat c}<1
string theories non-perturbatively. We are able to embed the type 0A and 0B
(A,A) minimal string theories into this single framework. The string theories
arise as special limits of a rich system of equations underpinned by an
integrable system known as the dispersive water wave hierarchy. We observe that
there are several other string-like limits of the system, and conjecture that
some of them are type IIA and IIB (A,D) minimal string backgrounds. We explain
how these and several string-like special points arise and are connected. In
some cases, the framework endows the theories with a non-perturbative
definition for the first time. Notably, we discover that the Painleve IV
equation plays a key role in organizing the string theory physics, joining its
siblings, Painleve I and II, whose roles have previously been identified in
this minimal string context.Comment: 49 pages, 4 figure
2+1 Dimensional QED and a Novel Phase Transition
We investigate the chiral phase transition in 2+1 dimensional QED. Previous
gap equation and lattice Monte-Carlo studies of symmetry breaking have found
that symmetry breaking ceases to occur when the number of fermion flavors
exceeds a critical value. Here we focus on the order of the transition. We find
that there are no light scalar degrees of freedom present as the critical
number of flavors is approached from above (in the symmetric phase). Thus the
phase transition is not second order, rendering irrelevant the renormalization
group arguments for a fluctuation induced transition. However, the order
parameter vanishes continuously in the broken phase, so this transition is also
unlike a conventional first order phase transition.Comment: 11 pages, Late
Effects of canopy architecture and microclimate on grapevine health in two training systems
Semi minimal pruned hedge (SMPH) is a time and cost saving grapevine training system, which is becoming more and more popular in German viticulture. In this study we compared the canopy architecture and its effect on the microclimate of SMPH trained grapevines with those of plants trained in vertical shoot positioning (VSP). We detected a 3 % points higher humidity and a 0.9 °C lower mean temperature within the complex canopy architecture of SMPH trained vines compared to VSP. Moreover, we investigated the influence of the differing microclimate, canopy and bunch architecture, as well as berry skin characteristics of the two training systems on the incidence of the major fungal grapevine diseases Downy Mildew, Powdery Mildew and Botrytis Bunch Rot, as well as on the occurrence and damage of the invasive insect pest Drosophila suzukii. We demonstrate that SMPH trained vines can be more susceptible to Downy Mildew and Powdery Mildew than VSP trained vines. The incidence of Botrytis Bunch Rot can be higher in the latter system, even if berry skin characteristics are the same in both training systems. We trapped a higher number of D. suzukii in SMPH canopies, however no increased berry damage was observed. Based on our results we recommend a more adapted plant protection regime for SMPH trained vines due to their higher susceptibility to the major fungal diseases. Furthermore, we propose a combination of SMPH and fungal resistant grapevine cultivars, e.g. 'Reberger', to achieve a more competitive, environmentally friendly and high quality grapevine production
Taxonomic revision of Garcinia section Garcinia (Clusiaceae)
Species of Garcinia sect. Garcinia are typically understorey trees in rain forest and are distributed from eastern India to Malesia. A taxonomic revision of Garcinia section Garcinia (Clusiaceae) has resulted in the recognition of 13 species, two of which have three varieties each. Several species are excluded from Garcinia section Garcinia, reported as insufficiently known, or reduced to synonymy. Five species, G. acuticosta, G. discoidea, G. exigua, G. ochracea and G. sangudsangud, and two varieties, G. diospyrifolia var. minor and G. mangostana var. borneensis, are newly described. Morphological characters that are important for sectional delimitation are terminally attached inflorescences of simple cymes, stamen bundles 4 or 4-angled, and fruits with a smooth surface. Species limits are defined on the basis of a combination of characters of the male flower (i.e. shape of stamens, presence of pistillode), type of fruit, and characters of the leaf (shape and size, venation pattern and glandular lines)
Observation of the Higgs Boson of strong interaction via Compton scattering by the nucleon
It is shown that the Quark-Level Linear Model (QLLM) leads
to a prediction for the diamagnetic term of the polarizabilities of the nucleon
which is in excellent agreement with the experimental data. The bare mass of
the meson is predicted to be MeV and the two-photon
width keV. It is argued that the
mass predicted by the QLLM corresponds to the reaction, i.e. to a -channel pole of the reaction.
Large -angle Compton scattering experiments revealing effects of the
meson in the differential cross section are discussed. Arguments are presented
that these findings may be understood as an observation of the Higgs boson of
strong interaction while being part of the constituent quark.Comment: 17 pages, 6 figure
Non-trivial Infrared Structure in (2+1)-dimensional Quantum Electrodynamics
We show that the gauge-fermion interaction in multiflavour
-dimensional quantum electrodynamics with a finite infrared cut-off is
responsible for non-fermi liquid behaviour in the infrared, in the sense of
leading to the existence of a non-trivial fixed point at zero momentum, as well
as to a significant slowing down of the running of the coupling at intermediate
scales as compared with previous analyses on the subject. Both these features
constitute deviations from fermi-liquid theory. Our discussion is based on the
leading- resummed solution for the wave-function renormalization of the
Schwinger-Dyson equations . The present work completes and confirms the
expectations of an earlier work by two of the authors (I.J.R.A. and N.E.M.) on
the non-trivial infrared structure of the theory.Comment: 10 pages (LaTex), 5 figures (Postscript
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