1,149 research outputs found
A geometric study of the dispersionless Boussinesq type equation
We discuss the dispersionless Boussinesq type equation, which is equivalent
to the Benney-Lax equation, being a system of equations of hydrodynamical type.
This equation was discussed in
. The results include: a
description of local and nonlocal Hamiltonian and symplectic structures,
hierarchies of symmetries, hierarchies of conservation laws, recursion
operators for symmetries and generating functions of conservation laws
(cosymmetries). Highly interesting are the appearances of operators that send
conservation laws and symmetries to each other but are neither Hamiltonian, nor
symplectic. These operators give rise to a noncommutative infinite-dimensional
algebra of recursion operators
Development, Isolation and Characterisation of a New Non-Virulent Mimosine-Degrading \u3cem\u3eKlebsiella pneumoniae\u3c/em\u3e Strain from the Rumen Liquor of German Steers by Using IBT-Goettinger Bioreactor
The tropical legume Leucaena leucocephala (leucaena) has many uses, including: a potential source of firewood and timber; for soil erosion control (Dijkman 1950); to provide shade; to enhance soil fertility; and as a nutritious forage for animal feed (Ruskin 1977). It is widely used as forage for cattle in tropical agriculture (Shelton 1998). In Myanmar, leucaena is used as a protein source in urea-molasses multi-nutrient blocks for ruminants (Ni Ni Maw et al. 2004). However, the use of leucaena as ruminant feed is not without problems, because it contains mimosine, a toxic anti-nutritional factor limiting its use as animal feed. Jones (1981) reported the absence of toxicity when leucaena was fed to goats and cattle in Hawaii and Indonesia. According to the low dihydroxypyridine (DHP) in urine of those animals, it was assumed that they could degrade mimosine and DHP. Hawaiian goats, but not Australian goats, could degrade 3,4-DHP ruminally (Jones and Megarrity 1983). Inoculation of susceptible animals with rumen liquor containing mimosine-degrading bacteria protected against DHP toxicity in ruminants (Jones and Lowry 1984). For maintaining mimosine-degrading bacteria, the donor animals should be fed on leucaena continuously and it is expensive to maintain their veterinary care. Hence, we tried to develop mimosine-degrading ruminal bacteria using a fermenter, intending to produce a source of inoculum for the routine control of leucaena toxicosis in ruminants
Vacuum Rabi splitting and intracavity dark state in a cavity-atoms system
We report experimental measurements of the transmission spectrum of an
optical cavity coupled with cold Rb atoms. We observe the multi-atom vacuum
Rabi splitting of a composite cavity and atom system. When a coupling field is
applied to the atoms and induces the resonant two-photon Raman transition with
the cavity field in a Lamda-type three-level system, we observe a cavity
transmission spectrum with two vacuum Rabi sidebands and a central peak
representing the intracavity dark state. The central peak linewidth is
significantly narrowed by the dark-state resonance and its position is
insensitive to the frequency change of the empty cavity.Comment: 11 pages, 4 figure
Detection of the fire blight biocontrol agent Bacillus subtilis BD170 (BioproÂź) in a Swiss apple orchard
Fire blight, caused by Erwinia amylovora, is a major disease threat to apple, pear and other pome fruit worldwide. The disease is widespread in Europe and has recently become established in Switzerland. Antibiotics are the most effective controls used in North America but these are not permitted for agricultural use in most European countries. A newly registered biological control product BioproÂź, based on the antagonist Bacillus subtilis strain BD170, is being used as an alternative strategy for fire blight management. A specific molecular marker was developed for monitoring the spread of this agent on blossoms after BioproÂź spray application in a Swiss apple orchard throughout the bloom period for 2years. Direct spraying resulted in efficient primary colonisation of pistils in flowers that were open at the time of treatment. Subsequent bacterial dissemination (secondary colonisation) of flowers that were closed or at bud stage at the time of treatment was observed but was found to be dependent on the timing of treatments relative to bloom stage in the orchard. Foraging honeybees were shown to be disseminators of BioproÂź. We also report detection of the biocontrol agent in honey collected from hives where bees were exposed by placing BioproÂź at the entrance or in the hatching nest and from hives that were simply placed in sprayed orchard
The catalase gene differentiates between some strains of Staphylococcus aureus ssp. anaerobius
The transcription factor Hey and nuclear lamins specify and maintain cell identity
The inability of differentiated cells to maintain their identity is a hallmark of age-related diseases. We found that the transcription factor Hey supervises the identity of differentiated enterocytes (ECs) in the adult Drosophila midgut. Lineage tracing established that Hey-deficient ECs are unable to maintain their unique nuclear organization and identity. To supervise cell identity, Hey determines the expression of nuclear lamins, switching from a stem-cell lamin configuration to a differentiated lamin configuration. Moreover, continued Hey expression is required to conserve large-scale nuclear organization. During aging, Hey levels decline, and EC identity and gut homeostasis are impaired, including pathological reprograming and compromised gut integrity. These phenotypes are highly similar to those observed upon acute targeting of Hey or perturbation of lamin expression in ECs in young adults. Indeed, aging phenotypes were suppressed by continued expression of Hey in ECs, suggesting that a Hey-lamin network safeguards nuclear organization and differentiated cell identity
Analysis of the large intestinal and faecal microbiota of horses with grass sickness using denaturing gradient gel electrophoresis
Research frontiers for improving our understanding of drought-induced tree and forest mortality
Accumulating evidence highlights increased mortality risks for trees during severe drought, particularly under warmer temperatures and increasing vapour pressure deficit (VPD). Resulting forest die-off events have severe consequences for ecosystem services, biophysical and biogeochemical landâatmosphere processes. Despite advances in monitoring, modelling and experimental studies of the causes and consequences of tree death from individual tree to ecosystem and global scale, a general mechanistic understanding and realistic predictions of drought mortality under future climate conditions are still lacking. We update a global tree mortality map and present a roadmap to a more holistic understanding of forest mortality across scales. We highlight priority research frontiers that promote: (1) new avenues for research on key tree ecophysiological responses to drought; (2) scaling from the tree/plot level to the ecosystem and region; (3) improvements of mortality risk predictions based on both empirical and mechanistic insights; and (4) a global monitoring network of forest mortality. In light of recent and anticipated large forest die-off events such a research agenda is timely and needed to achieve scientific understanding for realistic predictions of drought-induced tree mortality. The implementation of a sustainable network will require support by stakeholders and political authorities at the international level
The UMBRELLA SIOP-RTSG 2016 Wilms tumour pathology and molecular biology protocol
On the basis of the results of previous national and international trials and studies, the
Renal Tumour Study Group of the International Society of Paediatric Oncology (SIOPâRTSG) has
developed a new study protocol for paediatric renal tumours: the UMBRELLA SIOPâRTSG 2016
protocol (the UMBRELLA protocol). Currently, the overall outcomes of patients with Wilms
tumour are excellent, but subgroups with poor prognosis and increased relapse rates still exist.
The identification of these subgroups is of utmost importance to improve treatment stratification,
which might lead to reduction of the direct and late effects of chemotherapy. The UMBRELLA
protocol aims to validate new prognostic factors, such as blastemal tumour volume and molecular
markers, to further improve outcome. To achieve this aim, large, international, high-quality
databases are needed, which dictate optimization and international harmonization of specimen
handling and comprehensive sampling of biological material, refine definitions and improve
logistics for expert review. To promote broad implementation of the UMBRELLA protocol, the
updated SIOPâRTSG pathology and molecular biology protocol for Wilms tumours has been
outlined, which is a consensus from the SIOPâRTSG pathology panel
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