261 research outputs found
Review of the Leaf Essential Oils of the Genus Backhousia Sens. Lat. and a Report on the Leaf Essential Oils of B. gundarara and B. tetraptera
A review of the leaf oils of the 13 species now recognised in the genus Backhousia is presented. This review carries on from, and incorporates data from, an earlier (1995) review of the then recognised eight species. The leaf oils of two new species of Backhousia, B. gundarara and B. tetraptera are reported for the first time. B. gundarara contains a mixture of mono-and sesquiterpenes, with α-pinene (14%) and spathulenol (11%) being the main members. In B. tetraptera, the principal component of the mainly terpenoid leaf oil is myrtenyl acetate (20â40%). The review also incorporates the two species of the genus Choricarpia, which have been subsumed into Backhousia, viz. B. leptopetala and B. subargentea. Due to its history in Backhousia, Syzygium anisatum, which has been transferred out of Backhousia, is included in the review for historical reasons
Emplacement of oil in the Devonian Weardale Granite of northern England
The research was partly supported by NERC grant NE/M010953/1. MB is in receipt of a PhD studentship from PTDF (Nigeria). K.C. Dunham kindly provided samples from the Rookhope Borehole. P. Eakin collected bitumen at Moot Law. We are most grateful to very careful reviews by F. Smith and D. Holliday, which greatly improved presentation of the work.Peer reviewedPublisher PD
Relaciones culturales filipino-persas (I): las Rubaiyat de Manuel Bernabé
Life history trade-offs are a key notion in evolutionary biology, notably for understanding how selection shapes the diversity of traits among species. Despite the frequent study of such trade-offs, few studies synchronously investigate the effects of multiple factors, such as niche specialization and adaptation to harsh environments. We compared reproduction (fecundity and egg quality) in two sympatric couples (one habitat generalist and one specialist) of congeneric wolf spider species, in both Arctic and temperate habitats. We found that specialist species at both latitudes invested more in clutch size than did generalist species. We interpret this result as an optimization of clutch production. In the Arctic, the specialist was able to invest in fecundity with increasing body size at a much higher rate than the generalist species. In the temperate habitat, both species showed similar strategies: they increased quantity and quality of offspring relative to body size at the same rate. These results are consistent with the hypothesis that Arctic species must develop distinct strategies in order not to overlap each otherâs ecological niches as a consequence of limited food resources or niche space. We emphasize the need to test the role of plasticity and environmentally mediated effects of competition on arthropod fitness
Spatio-temporal instabilities for counterpropagating waves in periodic media.
Nonlinear evolution of coupled forward and backward fields in a multi-layered film is numerically investigated. We examine the role of longitudinal and transverse modulation instabilities in media of finite length with a homogeneous nonlinear susceptibilityfont face="Symbol"c/font((3)). The numerical solution of the nonlinear equations by a beam-propagation method that handles backward waves is described
Trace element geochemistry in the earliest terrestrial ecosystem, the Rhynie Chert
Acknowledgements JGTA is supported by the Natural Environment Research Council (grant NE/T003677/1). Samples were archived at the University of Aberdeen by N.H. Trewin, S.R. Fayers and C.M. Rice. Skilled technical support was provided by J. Johnston, J. Bowie, W. Ritchie and C. Taylor. We are grateful for the comments of two reviewers which improved the manuscript.Peer reviewedPublisher PD
Oxidized phospholipids are proinflammatory and proatherogenic in hypercholesterolaemic mice.
Oxidized phospholipids (OxPL) are ubiquitous, are formed in many inflammatory tissues, including atherosclerotic lesions, and frequently mediate proinflammatory changes 1 . Because OxPL are mostly the products of non-enzymatic lipid peroxidation, mechanisms to specifically neutralize them are unavailable and their roles in vivo are largely unknown. We previously cloned the IgM natural antibody E06, which binds to the phosphocholine headgroup of OxPL, and blocks the uptake of oxidized low-density lipoprotein (OxLDL) by macrophages and inhibits the proinflammatory properties of OxPL2-4. Here, to determine the role of OxPL in vivo in the context of atherogenesis, we generated transgenic mice in the Ldlr-/- background that expressed a single-chain variable fragment of E06 (E06-scFv) using the Apoe promoter. E06-scFv was secreted into the plasma from the liver and macrophages, and achieved sufficient plasma levels to inhibit in vivo macrophage uptake of OxLDL and to prevent OxPL-induced inflammatory signalling. Compared to Ldlr-/- mice, Ldlr -/- E06-scFv mice had 57-28% less atherosclerosis after 4, 7 and even 12 months of 1% high-cholesterol diet. Echocardiographic and histologic evaluation of the aortic valves demonstrated that E06-scFv ameliorated the development of aortic valve gradients and decreased aortic valve calcification. Both cholesterol accumulation and in vivo uptake of OxLDL were decreased in peritoneal macrophages, and both peritoneal and aortic macrophages had a decreased inflammatory phenotype. Serum amyloid A was decreased by 32%, indicating decreased systemic inflammation, and hepatic steatosis and inflammation were also decreased. Finally, the E06-scFv prolonged life as measured over 15 months. Because the E06-scFv lacks the functional effects of an intact antibody other than the ability to bind OxPL and inhibit OxLDL uptake in macrophages, these data support a major proatherogenic role of OxLDL and demonstrate that OxPL are proinflammatory and proatherogenic, which E06 counteracts in vivo. These studies suggest that therapies inactivating OxPL may be beneficial for reducing generalized inflammation, including the progression of atherosclerosis, aortic stenosis and hepatic steatosis
Zinc-alpha2-glycoprotein, dysglycaemia and insulin resistance: a systematic review and meta-analysis
To systematically review the current literature investigating associations between zinc-alpha2-glycoprotein (ZAG) and dysglycaemia (including type 2 diabetes (T2DM), poly-cystic-ovary syndrome (PCOS), pre-diabetes or insulin resistance). This included relationships between ZAG and continuous measures of insulin and glucose. Additionally, we performed a meta-analysis to estimate the extent that ZAG differs between individuals with or without dysglycaemia; whilst examining the potential influence of adiposity. A systematic search was performed on four databases for studies on circulating ZAG concentrations in adult human populations, comparing healthy controls to individuals with dysglycaemia. Key characteristics, including the mean ZAG concentrations (mgâLâ1), and any correlational statistics between ZAG and continuous measures of glucose, glycated haemoglobin (HbA1c) or insulin were extracted. Meta-analyses were performed to compare metabolically healthy controls to cases, and on studies that compared controls and cases considered overweight or obese (body mass index (BMI) â„25 kg.m2). 1575 papers were identified and 14 studies (16 cohorts) were considered eligible for inclusion. Circulating ZAG was lower in individuals with dysglycaemia compared to metabolically healthy controls (â4.14 [â8.17, â0.11] mg.Lâ1; I2 =â98.5%; pâ<â0.001). When using data from only studies with overweight or obese groups with or without dysglycaemia (three studies (four cohorts); pooled n =â332), the difference in circulating ZAG was no longer significant (â0.30 [â3.67, 3.07] mg. Lâ1; I2 =â28.0%; p =â0.225). These data suggest that ZAG may be implicated in dysglycaemia, although there was significant heterogeneity across different studies and the mediating effect of adiposity cannot be excluded. Therefore, more research is needed before robust conclusions can be drawn
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The Back Pain Consortium (BACPAC) Research Program Data Harmonization: Rationale for Data Elements and Standards
ObjectiveOne aim of the Back Pain Consortium (BACPAC) Research Program is to develop an integrated model of chronic low back pain that is informed by combined data from translational research and clinical trials. We describe efforts to maximize data harmonization and accessibility to facilitate Consortium-wide analyses.MethodsConsortium-wide working groups established harmonized data elements to be collected in all studies and developed standards for tabular and nontabular data (eg, imaging and omics). The BACPAC Data Portal was developed to facilitate research collaboration across the Consortium.ResultsClinical experts developed the BACPAC Minimum Dataset with required domains and outcome measures to be collected by use of questionnaires across projects. Other nonrequired domain-specific measures are collected by multiple studies. To optimize cross-study analyses, a modified data standard was developed on the basis of the Clinical Data Interchange Standards Consortium Study Data Tabulation Model to harmonize data structures and facilitate integration of baseline characteristics, participant-reported outcomes, chronic low back pain treatments, clinical exam, functional performance, psychosocial characteristics, quantitative sensory testing, imaging, and biomechanical data. Standards to accommodate the unique features of chronic low back pain data were adopted. Research units submit standardized study data to the BACPAC Data Portal, developed as a secure cloud-based central data repository and computing infrastructure for researchers to access and conduct analyses on data collected by or acquired for BACPAC.ConclusionsBACPAC harmonization efforts and data standards serve as an innovative model for data integration that could be used as a framework for other consortia with multiple, decentralized research programs
Hot embossing for fabrication of a microfluidic 3D cell culture
Clinically relevant studies of cell function in vitro require a physiologically-representative microenvironment possessing aspects such as a 3D extracellular matrix (ECM) and controlled biochemical and biophysical parameters. A polydimethylsiloxane (PDMS) microfluidic system with a 3D collagen gel has previously served for analysis of factors inducing different responses of cells in a 3D microenvironment under controlled biochemical and biophysical parameters. In the present study, applying the known commercially-viable manufacturing methods to a cyclic olefin copolymer (COC) material resulted in a microfluidic device with enhanced 3D gel capabilities, controlled surface properties, and improved potential to serve high-volume applications. Hot embossing and roller lamination molded and sealed the microfluidic device. A combination of oxygen plasma and thermal treatments enhanced the sealing, ensured proper placement of the 3D gel, and created controlled and stable surface properties within the device. Culture of cells in the new device indicated no adverse effects of the COC material or processing as compared to previous PDMS devices. The results demonstrate a methodology to transition microfludic devices for 3D cell culture from scientific research to high-volume applications with broad clinical impact.National Cancer Institute (U.S.) (award R21CA140096)Charles Stark Draper Laboratory (IR&D Grant
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