The molecular cloning and characterisation of cDNA coding for the alpha subunit of the acetylcholine receptor

The published version of this article is available at Oxford Journals in Nucleic Acids Research at http://nar.oxfordjournals.org/content/10/19/5809.full.pdf+htmlA rare cDNA coding for most of the α subunit of the Torpedo nicotinic acetylcholine receptor has been cloned into bacteria. The use of a mismatched oligonucleotide primer of reverse transcriptase facilitated the design of an efficient, specific probe for recombinant bacteria. DNA sequence analysis has enabled the elucidation of a large part of the polypeptide primary sequence which is discussed in relation to its acetylcholine binding activity and the location of receptor within the plasma membrane. When used as a radioactive probe, the cloned cDNA binds specifically to a single Torpedo mRNA species of about 2350 nucleotides in length but fails to show significant cross-hybridisation with a subunit mRNA extracted from cat muscle

Commentary on immune system associated diseases caused byviruses: The Role of EBV

In her review using the human Epstein–Barr virus (EBV) as an example, Dr. Chen intends to illustrate how host immune systems have evolved in response to pathogens or in many cases co-evolved with pathogens. She discusses why EBV in most people causes what appears to be a self-limiting lymphoproliferative disease (or is it? See her discussion of autoimmune diseases and EBV), but in a very small proportion of individuals the virus causes malignant diseases of severe consequence. She reviews some of the plausible explanations that may include interactions of environmental and host genetic factors resulting in EBV associated malignancies. She points out that EBV may not merely transform B cells, but it could also impact the host immune system on a much more global basis than previously realized. She also suggests that EBV associated diseases, in lieu of reflecting the pathogenic potential of the virus, are actually a reflection of the genetic predisposition of certain populations to the modulate immune system inappropriately in response to the virus infection. She supports this notion by detailing the abnormal modulation of NKT cells when the host is infected with EBV. For example, she cites a study that shows that the frequencies of regulatory CD8 + NKT, but not CD4 + NKT cells, in EBV associated Burkitt\u27s lymphoma (BL) and nasopharyngeal carcinoma (NPC) patients are much lower than CD8 + NKT levels in healthy EBV carriers (Yuling et al., 2009), concluding that a skewed NKT cell response might modify the pathogenesis caused by the virus. She also supports her supposition that EBV pathogenesis is likely due to improper immune modulation in response to the infection by reviewing the data associating autoimmune diseases with EBV infections, especially focusing on multiple sclerosis (MS). She cites a study by Serafini et al. (2007) in which it was found that that almost 100% of the early onset MS cases with the secondary progressive phase contain dysregulated EBV infected plasma cells in MS brains. She also reviews other studies that describe atypical responses of MS patients who have been exposed to EBV. Nevertheless, the cause and effect link, EBV to MS, is still tenuous, yet intriguing. She concludes that the malignancies associated with EBV infection and especially the autoimmune diseases associated with EBV infection may result from human genetic variations that cause the host to differentially modulate the immune response to EBV infection to the detriment of the host

Oxidation Behavior of a Pd_(43)Cu_(27)Ni_(10)P_(20) Bulk Metallic Glass and Foam in Dry Air

The oxidation behavior of both Pd_(43)Cu_(27)Ni_(10)P_(20) bulk metallic glass (Pd4-BMG) and its amorphous foam containing 45 pct porosity (Pd4-AF) was investigated over the temperature range of 343 K (70 °C) to 623 K (350 °C) in dry air. The results showed that virtually no oxidation occurred in the Pd4-BMG at T < 523 K (250 °C), revealing the alloy’s favorable oxidation resistance in this temperature range. In addition, the oxidation kinetics at T ≥ 523 K (250 °C) followed a parabolic-rate law, and the parabolic-rate constants (k_p values) generally increased with temperature. It was found that the oxidation k_p values of the Pd4-AF are slightly lower than those of the Pd4-BMG, indicating that the porous structure contributes to improving the overall oxidation resistance. The scale formed on the alloys was composed exclusively of CuO at T ≥ 548 K (275 °C), whose thickness gradually increased with increasing temperature. In addition, the amorphous structure remained unchanged at T ≤ 548 K (275 °C), while a triplex-phase structure developed after the oxidation at higher temperatures, consisting of Pd_2Ni_2P, Cu_3P, and Pd_3P

Systems, interactions and macrotheory

A significant proportion of early HCI research was guided by one very clear vision: that the existing theory base in psychology and cognitive science could be developed to yield engineering tools for use in the interdisciplinary context of HCI design. While interface technologies and heuristic methods for behavioral evaluation have rapidly advanced in both capability and breadth of application, progress toward deeper theory has been modest, and some now believe it to be unnecessary. A case is presented for developing new forms of theory, based around generic “systems of interactors.” An overlapping, layered structure of macro- and microtheories could then serve an explanatory role, and could also bind together contributions from the different disciplines. Novel routes to formalizing and applying such theories provide a host of interesting and tractable problems for future basic research in HCI

Submerged in the mainstream? A case study of an immigrant learner in a New Zealand primary classroom

Immigrant children from diverse language backgrounds face not only linguistic challenges when enrolled in mainstream English-medium classrooms, but also difficulties adjusting to an unfamiliar learning community. The culture of primary school classrooms in New Zealand typically reflects conventions across three dimensions: interactional, instructional task performance and cognitive-academic development. All three dimensions are underpinned by the culturally specific discourse conventions involved in language socialisation. New learners may be helped by classmates or their teacher to understand and successfully use these conventions, but left on their own they may sink rather than swim. This is a case study of one Taiwanese 11-year old boy, 'John', who entered a New Zealand primary classroom midway through the school year. John's basic conversational ability was sound, but he did not possess the interactive classroom skills needed to operate in the new culture of learning. Selected from a wider study of the classroom, transcript data from audio-recorded excerpts of John's interactions over several months with his teacher and classmates are interpreted from perspectives derived from sociocultural and language socialisation theories. The article concludes with a brief consideration of the extent to which John constructed, or was constrained from constructing meaningful learning experiences, and suggestions for further research and reflection

Sky cover from MFRSR observations

The diffuse all-sky surface irradiances measured at two nearby wavelengths in the visible spectral range and their modeled clear-sky counterparts are the main components of a new method for estimating the fractional sky cover of different cloud types, including cumuli. The performance of this method is illustrated using 1-min resolution data from a ground-based Multi-Filter Rotating Shadowband Radiometer (MFRSR). The MFRSR data are collected at the US Department of Energy Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) Southern Great Plains (SGP) site during the summer of 2007 and represent 13 days with cumuli. Good agreement is obtained between estimated values of the fractional sky cover and those provided by a well-established independent method based on broadband observations

Macrostate Data Clustering

We develop an effective nonhierarchical data clustering method using an analogy to the dynamic coarse graining of a stochastic system. Analyzing the eigensystem of an interitem transition matrix identifies fuzzy clusters corresponding to the metastable macroscopic states (macrostates) of a diffusive system. A "minimum uncertainty criterion" determines the linear transformation from eigenvectors to cluster-defining window functions. Eigenspectrum gap and cluster certainty conditions identify the proper number of clusters. The physically motivated fuzzy representation and associated uncertainty analysis distinguishes macrostate clustering from spectral partitioning methods. Macrostate data clustering solves a variety of test cases that challenge other methods.Comment: keywords: cluster analysis, clustering, pattern recognition, spectral graph theory, dynamic eigenvectors, machine learning, macrostates, classificatio

Barriers and facilitators to taking on diabetes self-management tasks in pre-adolescent children with type 1 diabetes: a qualitative study.

BACKGROUND: When children with type 1 diabetes approach adolescence, they are encouraged to become more involved in diabetes self-management. This study explored the challenges pre-adolescent children encounter when self-managing diabetes and the factors which motivate and enable them to take on new diabetes-related tasks. A key objective was to inform the support offered to pre-adolescent children. METHODS: In-depth interviews using age-appropriate questioning with 24 children (aged 9-12 years) with type 1 diabetes. Data were analysed using an inductive, thematic approach. RESULTS: Children reported several barriers to taking on self-management tasks. As well as seeking respite from managing diabetes, children described relying on their parents to: perform the complex maths involved in working out carbohydrate content in food; calculate insulin doses if they did not use a bolus advisor; and administer injections or insert a cannula in hard-to-reach locations. Children described being motivated to take on diabetes tasks in order to: minimise the pain experienced when others administered injections; alleviate the burden on their parents; and participate independently in activities with their peers. Several also discussed being motivated to take on diabetes-management responsibilities when they started secondary school. Children described being enabled to take on new responsibilities by using strategies which limited the need to perform complex maths. These included using labels on food packaging to determine carbohydrate contents, or choosing foods with carbohydrate values they could remember. Many children discussed using bolus advisors with pre-programmed ratios and entering carbohydrate on food labels or values provided by their parents to calculate insulin doses. Several also described using mobile phones to seek advice about carbohydrate contents in food. CONCLUSIONS: Our findings highlight several barriers which deter children from taking on diabetes self-management tasks, motivators which encourage them to take on new responsibilities, and strategies and technologies which enable them to become more autonomous. To limit the need to perform complex maths, children may benefit from using bolus advisors provided they receive regular review from healthcare professionals to determine and adjust pre-programmed insulin-to-carbohydrate ratios. Education and support should be age-specific to reflect children's changing involvement in self-managing diabetes