2,007 research outputs found
Review of: Krause, Richard A.: The Clay Sleeps: An Ethnoarchaeological Study of Three African Potters
Transcription of the dystrophin gene in Duchenne muscular dystrophy muscle
AbstractDystrophin is the recently discovered defective gene product in Duchenne and Becker muscular dystrophy (DMD and BMD). Dystrophin transcripts have been amplified and identified in diagnostic needle muscle biopsy samples using the polymerase chain reaction (PCR) procedure. Using 5′- and 3′-primers, dystrophin transcripts can be detected in both DMD and BMD muscle biopsies, on either side of defined deletions within the dystrophin gene
The Practice of Ethical Precepts: Dissecting Decision-Making Lawyers
The article describes the context for a major piece of interdisciplinary research undertaken in Ontario, Canada investigating whether the nature of ethical behaviour was changing over time: whether professionalism or profit was driving the behaviour of lawyers. The project had both conceptual and philosophical aspects and an empirical investigation. Previous research on professional ethics is canvassed, including studies of medical ethics, and the particular problems associated with research about the legal profession are identified. The full methodology of the empirical aspect of the research is described and all methodological decisions are discussed and justified. Appendices contain all research instruments. The results of a pre-test involving twenty lawyers demonstrated that better results were obtained through the use of anecdotes or critical incidents than through use of vignettes
Mentor, Mercenary or Melding: an Empirical Inquiry into the Role of the Laywer
This article examines the two models for the role of lawyers (the counselor approach and the hired gun approach) as espoused in legal literature. It then looks at the guidance given lawyers in Ontario, Canada, in choosing between the two roles in the Professional Conduct Handbook of The Law Society of Upper Canada. The Article then compares those models and the Law Society\u27s directives concerning them, to the actual roles practiced by lawyers as members of the Ontario Bar. The purpose of this Article is to determine the way in which the roles adopted by practising lawyers compare to the roles of a lawyer as articulated in legal literature and the professional ethical codes
cegpy: Modelling with Chain Event Graphs in Python
Chain event graphs (CEGs) are a recent family of probabilistic graphical
models that generalise the popular Bayesian networks (BNs) family. Crucially,
unlike BNs, a CEG is able to embed, within its graph and its statistical model,
asymmetries exhibited by a process. These asymmetries might be in the
conditional independence relationships or in the structure of the graph and its
underlying event space. Structural asymmetries are common in many domains, and
can occur naturally (e.g. a defendant vs prosecutor's version of events) or by
design (e.g. a public health intervention). However, there currently exists no
software that allows a user to leverage the theoretical developments of the CEG
model family in modelling processes with structural asymmetries. This paper
introduces cegpy, the first Python package for learning and analysing complex
processes using CEGs. The key feature of cegpy is that it is the first CEG
package in any programming language that can model processes with symmetric as
well as asymmetric structures. cegpy contains an implementation of Bayesian
model selection and probability propagation algorithms for CEGs. We illustrate
the functionality of cegpy using a structurally asymmetric dataset
The immobilization of Microcystis aeruginosa PCC7806 on a membrane nutrient-gradostat bioreacator for the production of the secondary metobolites
A module and an inoculation technique were developed that would allow for the efficient immobilization of Microcystis aeruginosa PCC7806 on a synthetic membrane. A variety of module types, membranes (ceramic, tubular polyethersulfone and externally skinless polyethersulfone capillary membrane), and methods of immobilization (adsorption, pressure filtration and a developed technique that involved drying a cell slurry on a membrane) were assessed. The morphological properties that affected the immobilization of Microcystis aeruginosa PCC7806, as well as the effects of immobilization upon cell morphology were assessed. Cells in the stationary growth phase, which had a well-developed extra-cellular polysaccharide layer and no gas vesicles, were optimal for immobilization. Microcystin production under immobilized conditions was assessed under different nitrate concentrations, light intensities, biofilm thickness and immobilization times. Additional work included assaying for Microcystin production of two airlift-grown cultures under a high light intensity and complete nutrient deprivation and the inoculation of a ceramic membrane. An immunological technique was used to elucidate where toxin production was greatest within a biofilm immobilized upon an externally skinless polyethersulfone capillary membrane. The externally skinless polyethersulfone capillary membrane was evaluated to assess homogeneity and the physical differences between membrane batches that led to the erratic, incomplete biofilm formation, as a biofilm of a constant thickness could not be immobilized. Microcystis aeruginosa PCC7806 was exposed to a variety of solvents in order to permeabilize the cyanobacteria, as that would have enabled a truly continuous extraction process for the metabolite. FDA hydrolysis had to be optimized in order to use it as an indicator of cell viability. In addition a single-step extraction of Microcystin was attempted using live bacteria. A capillary membrane module, containing the externally skinless polyethersulfone capillary membrane, inoculated using pressure filtration, was the most efficient combination to establish a biofilm. Cells that were no longer actively dividing and that lacked buoyancy displayed superior immobilization to cells that were actively dividing and buoyant. The immobilized cells did produce Microcystin but in much lower concentrations to cells grown in an airlift culture. Biofilms grown with a higher nitrate concentration, a lower biofilm thickness and a lower light intensity had a higher specific microcystin content, while biofilms with a higher nitrate concentration a lower light intensity and a longer growth period displayed the a greater toxin production per mm2 of membrane. Microcystin occurred at its highest concentration in cells just above the pore opening. The diffusion of nutrients occurred relatively quickly to the outside layers of the biofilm, with a true gradient being established laterally from these nutrient veins that were above the pores. Permeabilization of the cells proved unsuccessful, as cells that remained viable did not release the intracellular compound into the surrounding medium
Genetic Correction of Dystrophin Deficiency and Skeletal Muscle Remodeling in Adult MDX Mouse via Transplantation of Retroviral Producer Cells
Duchenne muscular dystrophy (DMD) is an X-linked, lethal
disease caused by mutations of the dystrophin gene. No
effective therapy is available, but dystrophin gene transfer
to skeletal muscle has been proposed as a treatment for
DMD. We have developed a strategy for efficient in vivo
gene transfer of dystrophin cDNA into regenerating skeletal
muscle. Retroviral producer cells, which release a vector
carrying the therapeutically active dystrophin minigene,
were mitotically inactivated and transplanted in adult
nude/
mdx
mice. Transplantation of 3
3
10
6
producer cells
in a single site of the tibialis anterior muscle resulted in the
transduction of between 5.5 and 18% total muscle fibers.
The same procedure proved also feasible in immunocompetent
mdx
mice under short-term pharmacological immunosuppression.
Minidystrophin expression was stable for up to
6 mo and led to
a
-sarcoglycan reexpression. Muscle stem
cells could be transduced in vivo using this procedure.
Transduced dystrophic skeletal muscle showed evidence of
active remodeling reminiscent of the genetic normalization
process which takes place in female DMD carriers. Overall,
these results demonstrate that retroviral-mediated dystrophin
gene transfer via transplantation of producer cells is a
valid approach towards the long-term goal of gene therapy
of DMD. (
J. Clin. Invest.
1997. 100:620–628
.
Visualization of diffusion limited antimicrobial peptide attack on supported lipid membranes
Understanding the mechanism of action of antimicrobial peptides (AMP) is fundamental to the development and design of peptide based antimicrobials. Utilizing fast-scan atomic force microscopy (AFM) we detail the attack of an AMP on both prototypical prokaryotic (DOPC:DOPG) and eukaryotic (DOPC:DOPE) model lipid membranes on the nanoscale and in real time. Previously shown to have a favourable therapeutic index, we study Smp43, an AMP with a helical-hinge-helical topology isolated from the venom of the North African scorpion Scorpio maurus palmatus. We observe the dynamic formation of highly branched defects being supported by 2D diffusion models and further experimental data from liposome leakage assays and quartz crystal microbalance-dissipation (QCM-D) analysis, we propose that Smp43 disrupts these membranes via a common mechanism, which we have termed ‘diffusion limited disruption’ that encompasses elements of both the carpet model and the expanding pore mechanism
- …