1,126 research outputs found
Uist Lagoons Survey
Scotland has around a hundred saline lagoons, coastal lochs that are not quite as saline as the sea. A small number of organisms are confined to these lochs, but most of these are very small and belong to groups that are difficult to identify. A consortium of specialists in identification at the National Museum of Scotland and ecologists sampled most of the saline lagoons on designated sites (SSSI and SAC) in the Uists, the area believed to have the best biodiversity of lagoon organisms in Scotland. The study not only confirmed the presence of these specialist species, but also that they were more widely distributed in the Uists than had been believed. Samples of the organisms have been placed in the permanent collections of the National Museum of Scotland and (for plants) in the Royal Botanic Gardens Edinburgh, where they will be available for future study
Asymmetric triplex metallohelices with high and selective activity against cancer cells
Small cationic amphiphilic α-helical peptides are emerging as agents for the treatment of cancer and infection, but they are costly and display unfavourable pharmacokinetics. Helical coordination complexes may offer a three-dimensional scaffold for the synthesis of mimetic architectures. However, the high symmetry and modest functionality of current systems offer little scope to tailor the structure to interact with specific biomolecular targets, or to create libraries for phenotypic screens. Here, we report the highly stereoselective asymmetric self-assembly of very stable, functionalized metallohelices. Their anti-parallel head-to-head-to-tail ‘triplex’ strand arrangement creates an amphipathic functional topology akin to that of the active sub-units of, for example, host-defence peptides and p53. The metallohelices display high, structure-dependent toxicity to the human colon carcinoma cell-line HCT116 p53++, causing dramatic changes in the cell cycle without DNA damage. They have lower toxicity to human breast adenocarcinoma cells (MDA-MB-468) and, most remarkably, they show no significant toxicity to the bacteria methicillin-resistant Staphylococcus aureus and Escherichia coli.
At a glanc
High-Dose Chemotherapy Followed by Peripheral and/or Bone Marrow Stem Cell Transplant in Patients With Advanced Sarcoma: Experience of a Canadian Centre
Purpose: Few reports have been published on the evaluation of stem cell auto transplantation for chemosensitive sarcomas.
Some suggest benefit, others do not. We present results of 24 patients with sarcoma undergoing autotransplantation at a
Canadian institution
The three-dimensional Anderson model of localization with binary random potential
We study the three-dimensional two-band Anderson model of localization and
compare our results to experimental results for amorphous metallic alloys
(AMA). Using the transfer-matrix method, we identify and characterize the
metal-insulator transitions as functions of Fermi level position, band
broadening due to disorder and concentration of alloy composition. The
appropriate phase diagrams of regions of extended and localized electronic
states are studied and qualitative agreement with AMA such as Ti-Ni and Ti-Cu
metallic glasses is found. We estimate the critical exponents nu_W, nu_E and
nu_x when either disorder W, energy E or concentration x is varied,
respectively. All our results are compatible with the universal value nu ~ 1.6
obtained in the single-band Anderson model.Comment: 9 RevTeX4 pages with 11 .eps figures included, submitted to PR
A categorical foundation for Bayesian probability
Given two measurable spaces and with countably generated
-algebras, a perfect prior probability measure on and a
sampling distribution , there is a corresponding inference
map which is unique up to a set of measure zero. Thus,
given a data measurement , a posterior probability
can be computed. This procedure is iterative: with
each updated probability , we obtain a new joint distribution which in
turn yields a new inference map and the process repeats with each
additional measurement. The main result uses an existence theorem for regular
conditional probabilities by Faden, which holds in more generality than the
setting of Polish spaces. This less stringent setting then allows for
non-trivial decision rules (Eilenberg--Moore algebras) on finite (as well as
non finite) spaces, and also provides for a common framework for decision
theory and Bayesian probability.Comment: 15 pages; revised setting to more clearly explain how to incorporate
perfect measures and the Giry monad; to appear in Applied Categorical
Structure
Critical Dynamics of a Vortex Loop Model for the Superconducting Transition
We calculate analytically the dynamic critical exponent measured in
Monte Carlo simulations for a vortex loop model of the superconducting
transition, and account for the simulation results. In the weak screening
limit, where magnetic fluctuations are neglected, the dynamic exponent is found
to be . In the perfect screening limit, . We relate
to the actual value of observable in experiments and find that , consistent with some experimental results
Evaluation of two lyophilized molecular assays to rapidly detect foot-and-mouth disease virus directly from clinical samples in field settings
Accurate, timely diagnosis is essential for the control, monitoring and eradication of foot‐and‐mouth disease (FMD). Clinical samples from suspect cases are normally tested at reference laboratories. However, transport of samples to these centralized facilities can be a lengthy process that can impose delays on critical decision making. These concerns have motivated work to evaluate simple‐to‐use technologies, including molecular‐based diagnostic platforms, that can be deployed closer to suspect cases of FMD. In this context, FMD virus (FMDV)‐specific reverse transcription loop‐mediated isothermal amplification (RT‐LAMP) and real‐time RT‐PCR (rRT‐PCR) assays, compatible with simple sample preparation methods and in situ visualization, have been developed which share equivalent analytical sensitivity with laboratory‐based rRT‐PCR. However, the lack of robust ‘ready‐to‐use kits’ that utilize stabilized reagents limits the deployment of these tests into field settings. To address this gap, this study describes the performance of lyophilized rRT‐PCR and RT‐LAMP assays to detect FMDV. Both of these assays are compatible with the use of fluorescence to monitor amplification in real‐time, and for the RT‐LAMP assays end point detection could also be achieved using molecular lateral flow devices. Lyophilization of reagents did not adversely affect the performance of the assays. Importantly, when these assays were deployed into challenging laboratory and field settings within East Africa they proved to be reliable in their ability to detect FMDV in a range of clinical samples from acutely infected as well as convalescent cattle. These data support the use of highly sensitive molecular assays into field settings for simple and rapid detection of FMDV
Social trajectories or disrupted identities? : Changing and competing models of teacher professionalism under New Labour
Since the 1988 Education Reform Act, the teacher’s role in England has changed in many ways, a process which intensified under New Labour after 1997. Conceptions of teacher professionalism have become more structured and formalized, often heavily influenced by government policy objectives. Career paths have become more diverse and specialised. In this article, three post-1997 professional roles are given consideration as examples of these new specialised career paths: Higher Level Teaching Assistants, Teach First trainees and Advanced Skills Teachers. The article goes on to examine such developments within teaching, using Bourdieu’s concept of habitus to inform the analysis, as well as Bernstein’s theories of knowledge and identity. The article concludes that there has been considerable specialization and subsequent fragmentation of roles within the teaching profession, as part of workforce remodelling initiatives. However, there is still further scope for developing a greater sense of professional cohesion through social activism initiatives, such as the children's agenda. This may produce more stable professional identities in the future as the role of teachers within the wider children’s workforce is clarified
Race and sex: teachers' views on who gets ahead in schools?
The research reported here was part of a large study of the impact of age, disability, race and sex on the teaching profession in England. The basic question asked in this research was how do these factors interact with career aspirations and achievements of classteachers, promoted teachers and headteachers? There were three different data sources: a large postal survey drawn from diverse geographic regions across England with over 2000 respondents; face‐to‐face individual interviews with over 100 teachers in 18 case study schools from across all of the main regions of England; discussions with special interest groups of teachers. Not surprisingly, the answer to the above question was complex. Nonetheless, the paper's conclusion highlights some of the noteworthy themes across this broad sample of teachers from primary, secondary and special schools
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