3,065 research outputs found
Draft genome sequence of the naturally competent Bacillus simplex strain WY10
ABSTRACT
We sequenced a naturally competent bacterial isolate, WY10, cultured from a Wyoming soil sample. Sequence analysis revealed that WY10 is a novel strain of
Bacillus simplex
. To our knowledge, WY10 is the first
B. simplex
strain to be characterized as naturally competent for DNA uptake by transformation.
</jats:p
Emergence of long-range order in BaTiO3 from local symmetry-breaking distortions
By using a symmetry motivated basis to evaluate local distortions against
pair distribution function data (PDF), we show without prior bias, that the
off-centre Ti displacements in the archetypal ferroelectric BaTiO3 are zone
centred and rhombohedral-like in nature across its known ferroelectric and
paraelectric phases. With our newly-gained insight we construct a simple Monte
Carlo (MC) model which captures our main experimental findings and demonstrate
how the rich crystallographic phase diagram of BaTiO3 emerges from correlations
of local symmetry-breaking distortions alone. Our results strongly support the
order-disorder picture for these phase transitions, but can also be reconciled
with the soft-mode theory of BaTiO3 that is supported by some spectroscopic
techniques.Comment: 5 pages, 3 figure
Recommended from our members
Fortification and health: challenges and opportunities.
Fortification is the process of adding nutrients or non-nutrient bioactive components to edible products (e.g., food, food constituents, or supplements). Fortification can be used to correct or prevent widespread nutrient intake shortfalls and associated deficiencies, to balance the total nutrient profile of a diet, to restore nutrients lost in processing, or to appeal to consumers looking to supplement their diet. Food fortification could be considered as a public health strategy to enhance nutrient intakes of a population. Over the past century, fortification has been effective at reducing the risk of nutrient deficiency diseases such as beriberi, goiter, pellagra, and rickets. However, the world today is very different from when fortification emerged in the 1920s. Although early fortification programs were designed to eliminate deficiency diseases, current fortification programs are based on low dietary intakes rather than a diagnosable condition. Moving forward, we must be diligent in our approach to achieving effective and responsible fortification practices and policies, including responsible marketing of fortified products. Fortification must be applied prudently, its effects monitored diligently, and the public informed effectively about its benefits through consumer education efforts. Clear lines of authority for establishing fortification guidelines should be developed and should take into account changing population demographics, changes in the food supply, and advances in technology. This article is a summary of a symposium presented at the ASN Scientific Sessions and Annual Meeting at Experimental Biology 2014 on current issues involving fortification focusing primarily on the United States and Canada and recommendations for the development of responsible fortification practices to ensure their safety and effectiveness
What does supervision help with? a survey of 315 social workers in the UK
What does social work supervision help with? There are many different models of supervision and an increasing amount of research. Much of this is concerned with the content of supervision and how supervisors (and supervisees) should behave — and these are important concerns. But even more important is the question of who or what supervision helps with. Supervision is widely considered to have many different functions but in the context of UK local authority social work, must ultimately prove itself as a method for helping people who use services. This article reports on a survey of 315 social workers from UK local authorities. Most reported that supervision helps primarily with management oversight and accountability. However, the small number of practitioners who received regular group supervision and those who received supervision more frequently said it helped with a much broader range of things
Cytoplasmic-nuclear male sterility in pearl millet: comparative RFLP and transcript analyses of isonuclear male-sterile lines
 The identification of diagnostic cytoplasmic molecular markers is of prime interest to pearl millet breeders wishing to identify sources of cytoplasmic-nuclear male sterility (CMS) which can be used as an alternative to the single source currently used in the production of F1 hybrid seed. Here, we report the classification of five pearl millet CMS sources based on RFLP analysis of isonuclear lines carried out using mitochondrial gene-specific DNA probes in combination with eight restriction endonucleases. On the basis of RFLP data, the five CMS cytoplasms can be distinguished from each other and from the isonuclear fertile cytoplasm. In addition, based on cox1, cox3, atp6 and atp9 polymorphisms, these lines can be classified into two major groups: one corresponds to A5, Aegp, Av and A1 cytoplasms, and the other consists of the A4 cytoplasm. Our results suggest that a rearrangement involving the cox1 gene might be related to CMS in the first group (A5, Aegp, Av and A1), whereas a rearrangement within the atp6/cox3 cluster region might be related to CMS in the second group (A4)
Is it feasible to conduct a randomised controlled trial of pretransplant exercise (prehabilitation) for patients with multiple myeloma awaiting autologous haematopoietic stem cell transplantation? Protocol for the PREeMPT study
Introduction While myeloma is an incurable malignancy, developments in disease management have led to increased life expectancy in recent years. Treatment typically involves stem-cell transplantation. Increased survival rates equate to more patients living with the burden of both the disease and its treatment for increasing number of years, rendering myeloma a long-term condition. Evidence exists to demonstrate the benefits of exercise for patients recovering from stem-cell transplantation, and prehabilitation—exercise before treatment—has been shown to be effective in other disease areas. To date there has been no research into prehabilitation in patients with myeloma awaiting transplantation treatment. Our objective is to determine whether it is feasible to conduct a randomised controlled trial into pretransplant exercise for patients with multiple myeloma who are awaiting autologous stem-cell transplantation. Methods and analysis This mixed methods study identifies patients with diagnosis of multiple myeloma who have been assigned to the autologous transplantation list and invites them to participate in six weekly sessions of individualised, supervised exercise while awaiting transplantation. Quantitative data to determine feasibility targets include rates of recruitment, adherence and adverse events, and outcome measures including 6 min walking distance test and quality of life. Qualitative interviews are undertaken with a purposive sample of patients to capture their experiences of the study and the intervention
Topology of amorphous tetrahedral semiconductors on intermediate lengthscales
Using the recently-proposed ``activation-relaxation technique'' for
optimizing complex structures, we develop a structural model appropriate to
a-GaAs which is almost free of odd-membered rings, i.e., wrong bonds, and
possesses an almost perfect coordination of four. The model is found to be
superior to structures obtained from much more computer-intensive tight-binding
or quantum molecular-dynamics simulations. For the elemental system a-Si, where
wrong bonds do not exist, the cost in elastic energy for removing odd-membered
rings is such that the traditional continuous-random network is appropriate.
Our study thus provides, for the first time, direct information on the nature
of intermediate-range topology in amorphous tetrahedral semiconductors.Comment: 4 pages, Latex and 2 postscript figure
Middle and Late Pleistocene environmental history of the Marsworth area, south-central England
To elucidate the Middle and Late Pleistocene environmental history of south-central England, we report the stratigraphy, sedimentology, palaeoecology and geochronology of some deposits near the foot of the Chiltern Hills scarp at Marsworth, Buckinghamshire. The Marsworth site is important because its sedimentary sequences contain a rich record of warm stages and cold stages, and it lies close to the Anglian glacial limit. Critical to its history are the origin and age of a brown pebbly silty clay (diamicton) previously interpreted as weathered till.
The deposits described infill a river channel incised into chalk bedrock. They comprise clayey, silty and gravelly sediments, many containing locally derived chalk and some with molluscan, ostracod and vertebrate remains. Most of the deposits are readily attributed to periglacial and fluvial processes, and some are dated by optically stimulated luminescence to Marine Isotope Stage (MIS) 6. Although our sedimentological data do not discriminate between a glacial or periglacial interpretation of the diamicton, amino-acid dating of three molluscan taxa from beneath it indicates that it is younger than MIS 9 and older than MIS 5e. This makes a glacial interpretation unlikely, and we interpret the diamicton as a periglacial slope deposit.
The Pleistocene history reconstructed for Marsworth identifies four key elements: (1) Anglian glaciation during MIS 12 closely approached Marsworth, introducing far-travelled pebbles such as Rhaxella chert and possibly some fine sand minerals into the area. (2) Interglacial environments inferred from fluvial sediments during MIS 7 varied from fully interglacial conditions during sub-stages 7e and 7c, cool temperate conditions during sub-stage 7b or 7a, temperate conditions similar to those today in central England towards the end of the interglacial, and cool temperate conditions during sub-stage 7a. (3) Periglacial activity during MIS 6 involved thermal contraction cracking, permafrost development, fracturing of chalk bedrock, fluvial activity, slopewash, mass movement and deposition of loess and coversand. (4) Fully interglacial conditions during sub-stage 5e led to renewed fluvial activity, soil formation and acidic weathering
- …