74 research outputs found
An Examination of Not-For-Profit Stakeholder Networks for Relationship Management: A Small-Scale Analysis on Social Media
Using a small-scale descriptive network analysis approach, this study highlights the importance of stakeholder networks for identifying valuable stakeholders and the management of existing stakeholders in the context of mental health not-for-profit services. We extract network data from the social media brand pages of three health service organizations from the U.S., U.K., and Australia, to visually map networks of 579 social media brand pages (represented by nodes), connected by 5,600 edges. This network data is analyzed using a collection of popular graph analysis techniques to assess the differences in the way each of the service organizations manage stakeholder networks. We also compare node meta-information against basic topology measures to emphasize the importance of effectively managing relationships with stakeholders who have large external audiences. Implications and future research directions are also discussed
A steric tethering approach enables palladium-catalysed C-H activation of primary amino alcohols.
Aliphatic primary amines are a class of chemical feedstock essential to the synthesis of higher-order nitrogen-containing molecules, commonly found in biologically active compounds and pharmaceutical agents. New methods for the construction of complex amines remain a continuous challenge to synthetic chemists. Here, we outline a general palladium-catalysed strategy for the functionalization of aliphatic C-H bonds within amino alcohols, an important class of small molecule. Central to this strategy is the temporary conversion of catalytically incompatible primary amino alcohols into hindered secondary amines that are capable of undergoing a sterically promoted palladium-catalysed C-H activation. Furthermore, a hydrogen bond between amine and catalyst intensifies interactions around the palladium and orients the aliphatic amine substituents in an ideal geometry for C-H activation. This catalytic method directly transforms simple, easily accessible amines into highly substituted, functionally concentrated and structurally diverse products, and can streamline the synthesis of biologically important amine-containing molecules.We are grateful to the Marie Curie Foundation (D.P. & J.C.), EPSRC (T.W.G.), the ERC (V.D.), and the ERC and EPSRC for Fellowships (M.J.G.). We are grateful to Adam Smalley for DFT calculations and Yohei Shimidzu for assistance with optimization of the C–H acetoxylation reaction. Mass spectrometry data was acquired at the EPSRC UK National Mass Spectrometry Facility at Swansea University. The authors declare no competing financial interests.This is the author accepted manuscript. The final version is available from NPG via http://dx.doi.org/10.1038/nchem.236
Proteome analysis of human gastric cardia adenocarcinoma by laser capture microdissection
<p>Abstract</p> <p>Background</p> <p>The incidence of gastric cardiac adenocarcinoma (GCA) has been increasing in the past two decades in China, but the molecular changes relating to carcinogenesis have not been well characterised.</p> <p>Methods</p> <p>In this study, we used a comparative proteomic approach to analyse the malignant and nonmalignant gastric cardia epithelial cells isolated by navigated laser capture microdissection (LCM) from paired surgical specimens of human GCA.</p> <p>Results</p> <p>Twenty-seven spots corresponding to 23 proteins were consistently differentially regulated. Fifteen proteins were shown to be up-regulated, while eight proteins were shown to be down-regulated in malignant cells compared with nonmalignant columnar epithelial cells. The identified proteins appeared to be involved in metabolism, chaperone, antioxidation, signal transduction, apoptosis, cell proliferation, and differentiation. In addition, expressions of HSP27, 60, and Prx-2 in GCA specimens were further confirmed by immunohistochemical and western blot analyses.</p> <p>Conclusion</p> <p>These data indicate that the combination of navigated LCM with 2-DE provides an effective strategy for discovering proteins that are differentially expressed in GCA. Such proteins may contribute in elucidating the molecular mechanisms of GCA carcinogenesis. Furthermore, the combination provides potential clinical biomarkers that aid in early detection and provide potential therapeutic targets.</p
Maintaining RNA integrity in a homogeneous population of mammary epithelial cells isolated by Laser Capture Microdissection
Background: Laser-capture microdissection (LCM) that enables the isolation of specific cell populations from complex tissues under morphological control is increasingly used for subsequent gene expression studies in cell biology by methods such as real-time quantitative PCR (qPCR), microarrays and most recently by RNA-sequencing. Challenges are i) to select precisely and efficiently cells of interest and ii) to maintain RNA integrity. The mammary gland which is a complex and heterogeneous tissue, consists of multiple cell types, changing in relative proportion during its development and thus hampering gene expression profiling comparison on whole tissue between physiological stages. During lactation, mammary epithelial cells (MEC) are predominant. However several other cell types, including myoepithelial (MMC) and immune cells are present, making it difficult to precisely determine the specificity of gene expression to the cell type of origin. In this work, an optimized reliable procedure for producing RNA from alveolar epithelial cells isolated from frozen histological sections of lactating goat, sheep and cow mammary glands using an infrared-laser based Arcturus Veritas LCM (Applied Biosystems®) system has been developed. The following steps of the microdissection workflow: cryosectioning, staining, dehydration and harvesting of microdissected cells have been carefully considered and designed to ensure cell capture efficiency without compromising RNA integrity.[br/] Results: The best results were obtained when staining 8 μm-thick sections with Cresyl violet® (Ambion, Applied Biosystems®) and capturing microdissected cells during less than 2 hours before RNA extraction. In addition, particular attention was paid to animal preparation before biopsies or slaughtering (milking) and freezing of tissue blocks which were embedded in a cryoprotective compound before being immersed in isopentane. The amount of RNA thus obtained from ca.150 to 250 acini (300,000 to 600,000 μm2) ranges between 5 to 10 ng. RNA integrity number (RIN) was ca. 8.0 and selectivity of this LCM protocol was demonstrated through qPCR analyses for several alveolar cell specific genes, including LALBA (α-lactalbumin) and CSN1S2 (αs2-casein), as well as Krt14 (cytokeratin 14), CD3e and CD68 which are specific markers of MMC, lymphocytes and macrophages, respectively.[br/] Conclusions: RNAs isolated from MEC in this manner were of very good quality for subsequent linear amplification, thus making it possible to establish a referential gene expression profile of the healthy MEC, a useful platform for tumor biomarker discovery
Imaging aspects of cardiovascular disease at the cell and molecular level
Cell and molecular imaging has a long and distinguished history. Erythrocytes were visualized microscopically by van Leeuwenhoek in 1674, and microscope technology has evolved mightily since the first single-lens instruments, and now incorporates many types that do not use photons of light for image formation. The combination of these instruments with preparations stained with histochemical and immunohistochemical markers has revolutionized imaging by allowing the biochemical identification of components at subcellular resolution. The field of cardiovascular disease has benefited greatly from these advances for the characterization of disease etiologies. In this review, we will highlight and summarize the use of microscopy imaging systems, including light microscopy, electron microscopy, confocal scanning laser microscopy, laser scanning cytometry, laser microdissection, and atomic force microscopy in conjunction with a variety of histochemical techniques in studies aimed at understanding mechanisms underlying cardiovascular diseases at the cell and molecular level
Context, cognition and communication in language
Questions pertaining to the unique structure and organisation of language have a
long history in the field of linguistics. In recent years, researchers have explored
cultural evolutionary explanations, showing how language structure emerges from
weak biases amplified over repeated patterns of learning and use. One outstanding
issue in these frameworks is accounting for the role of context. In particular,
many linguistic phenomena are said to to be context-dependent; interpretation
does not take place in a void, and requires enrichment from the current state
of the conversation, the physical situation, and common knowledge about the
world. Modelling the relationship between language structure and context is
therefore crucial for developing a cultural evolutionary approach to language.
One approach is to use statistical analyses to investigate large-scale, cross-cultural
datasets. However, due to the inherent limitations of statistical analyses, especially
with regards to the inadequacy of these methods to test hypotheses about
causal relationships, I argue that experiments are better suited to address questions
pertaining to language structure and context. From here, I present a series
of artificial language experiments, with the central aim being to test how
manipulations to context influence the structure and organisation of language.
Experiment 1 builds upon previous work in iterated learning and communication
games through demonstrating that the emergence of optimal communication systems
is contingent on the contexts in which languages are learned and used. The
results show that language systems gradually evolve to only encode information
that is informative for conveying the intended meaning of the speaker - resulting
in markedly different systems of communication. Whereas Experiment 1 focused
on how context influences the emergence of structure, Experiments 2 and 3 investigate
under what circumstances do manipulations to context result in the loss
of structure. While the results are inconclusive across these two experiments,
there is tentative evidence that manipulations to context can disrupt structure,
but only when interacting with other factors. Lastly, Experiment 4 investigates
whether the degree of signal autonomy (the capacity for a signal to be interpreted without recourse to contextual information) is shaped by manipulations
to contextual predictability: the extent to which a speaker can estimate and exploit
contextual information a hearer uses in interpreting an utterance. When
the context is predictable, speakers organise languages to be less autonomous
(more context-dependent) through combining linguistic signals with contextual
information to reduce effort in production and minimise uncertainty in comprehension.
By decreasing contextual predictability, speakers increasingly rely on
strategies that promote more autonomous signals, as these signals depend less on
contextual information to discriminate between possible meanings. Overall, these
experiments provide proof-of-concept for investigating the relationship between
language structure and context, showing that the organisational principles underpinning
language are the result of competing pressures from context, cognition,
and communication
Recommended from our members
Design of the ECCE Detector for the Electron Ion Collider
Preprint submitted to Nuclear Instruments and Methods A. The file archived on this institutional repository has not been certified by peer review.32 pages, 29 figures, 9 tablesThe EIC Comprehensive Chromodynamics Experiment (ECCE) detector has been designed to address the full scope of the proposed Electron Ion Collider (EIC) physics program as presented by the National Academy of Science and provide a deeper understanding of the quark-gluon structure of matter. To accomplish this, the ECCE detector offers nearly acceptance and energy coverage along with excellent tracking and particle identification. The ECCE detector was designed to be built within the budget envelope set out by the EIC project while simultaneously managing cost and schedule risks. This detector concept has been selected to be the basis for the EIC project detector.Office of Science in the Department of Energy, the National Science Foundation, and the Los Alamos National
Laboratory Laboratory Directed Research and Development (LDRD) 20200022DR; This research used resources of the Compute and Data Environment for Science (CADES) at the Oak Ridge National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC05-
00OR22725. The work of AANL group are supported by the Science Committee of RA, in the frames of the research project # 21AG-1C028. And we gratefully acknowledge that support of Brookhaven National Lab and the Thomas Jefferson National Accelerator Facility which are operated under contracts DESC0012704 and DE-AC05-06OR23177 respectivel
- …