2,708 research outputs found
Two major ruminant acute phase proteins, haptoglobin and serum amyloid A, as serum biomarkers during active sheep scab infestation
Two ruminant acute phase proteins (APPs), haptoglobin (Hp) and serum amyloid A (SAA), were evaluated as serum biomarkers (BMs) for sheep scabâa highly contagious ectoparasitic disease caused by the mite Psoroptes ovis, which is a major welfare and production threat worldwide. The levels of both APPs increased in serum following experimental infestation of sheep with P. ovis, becoming statistically significantly elevated from pre-infestation levels at 4 weeks post-infestation. Following successful treatment of infested sheep with an endectocide, Hp and SAA serum levels declined rapidly, with half lives of less than 3 days. In contrast, serum IgG levels which specifically bound the P. ovis-derived diagnostic antigen Pso o 2 had a half-life of 56 days. Taking into account pre-infestation serum levels, rapidity of response to infestation and test sensitivity at the estimated optimum cut-off values, SAA was the more discriminatory marker. These studies illustrated the potential of SAA and Hp to indicate current sheep scab infestation status and to augment the existing Pso o 2 serological assay to give disease-specific indications of both infestation and successful treatment
A Relational Database for the Discovery of Genes Encoding Amino Acid Biosynthetic Enzymes in Pathogenic Fungi
Fungal phytopathogens continue to cause major economic impact, either directly, through crop losses, or due to the costs of fungicide application. Attempts to understand
these organisms are hampered by a lack of fungal genome sequence data. A
need exists, however, to develop specific bioinformatics tools to collate and analyse the
sequence data that currently is available. A web-accessible gene discovery database
(http://cogeme.ex.ac.uk/biosynthesis.html) was developed as a demonstration tool for
the analysis of metabolic and signal transduction pathways in pathogenic fungi using
incomplete gene inventories. Using Bayesian probability to analyse the currently available
gene information from pathogenic fungi, we provide evidence that the obligate
pathogen Blumeria graminis possesses all amino acid biosynthetic pathways found
in free-living fungi, such as Saccharomyces cerevisiae. Phylogenetic analysis was also
used to deduce a gene history of succinate-semialdehyde dehydrogenase, an enzyme
in the glutamate and lysine biosynthesis pathways. The database provides a tool and
methodology to researchers to direct experimentation towards predicting pathway
conservation in pathogenic microorganisms
An Expanded Modern Coexistence Theory for Empirical Applications
Understanding longâterm coexistence of numerous competing species is a longstanding challenge in ecology. Progress requires determining which processes and species differences are most important for coexistence when multiple processes operate and species differ in many ways. Modern coexistence theory (MCT), formalized by Chesson, holds out the promise of doing that, but empirical applications remain scarce. We argue that MCT\u27s mathematical complexity and subtlety have obscured the simplicity and power of its underlying ideas and hindered applications. We present a general computational approach that extends our previous solution for the storage effect to all of standard MCT\u27s spatial and temporal coexistence mechanisms, and also processâdefined mechanisms amenable to direct study such as resource partitioning, indirect competition, and life history tradeâoffs. The main components are a method to partition population growth rates into contributions from different mechanisms and their interactions, and numerical calculations in which some mechanisms are removed and others retained. We illustrate how our approach handles features that have not been analyzed in the standard framework through several case studies: competing diatom species under fluctuating temperature, plantâsoil feedbacks in grasslands, facilitation in a beach grass community, and niche differences with independent effects on recruitment, survival and growth in sagebrush steppe
Novel pyrrolobenzodiazepine benzofused hybrid molecules inhibit NF-ÎșB activity and synergise with bortezomib and ibrutinib in hematological cancers
Chronic lymphocytic leukemia (CLL) and multiple myeloma (MM) are incurable hematological malignancies that are pathologically linked with aberrant NF-ÎșB activation. In this study, we identified a group of novel C8-linked benzofused Pyrrolo[2,1-c][1,4]benzodiazepines (PBD) monomeric hybrids capable of sequence-selective inhibition of NF-ÎșB with low nanomolar LD50 values in CLL (n=46) and MM cell lines (n=5). The lead compound, DC-1-192, significantly inhibited NF-ÎșB DNA binding after just 4h exposure and demonstrating inhibitory effects on both canonical and non-canonical NF-ÎșB subunits. In primary CLL cells, sensitivity to DC-1-192 was inversely correlated with RelA subunit expression (r2=0.2) and samples with BIRC3 or NOTCH1 mutations showed increased sensitivity (P=0.001). RNA-sequencing and gene set enrichment analysis confirmed the over-representation of NF-ÎșB regulated genes in the down-regulated gene list. Furthermore, In vivo efficacy studies in NOD/SCID mice, using a systemic RPMI 8226 human multiple myeloma xenograft model, showed that DC-1-192 significantly prolonged survival (P=0.017). In addition, DC1-192 showed synergy with bortezomib and ibrutinib; synergy with ibrutinib was enhanced when CLL cells were co-cultured on CD40L-expressing fibroblasts in order to mimic the cytoprotective lymph node microenvironment (P = 0.01). Given that NF-ÎșB plays a role in both bortezomib and ibrutinib resistance mechanisms, these data provide a strong rationale for the use of DC-1-192 in the treatment of NF-ÎșB-driven cancers, particularly in the context of relapsed/refractory disease
Functional assessment of the NMDA receptor variant GluN2A (R586K)
Background: The N-methyl-D-aspartate receptor (NMDAR) is an ionotropic glutamate receptor that has important roles in synaptogenesis, synaptic transmission, and synaptic plasticity. Recently, a large number of rare genetic variants have been found in NMDAR subunits in people with neurodevelopmental disorders, and also in healthy individuals. One such is the GluN2AR586K variant (GRIN2AG1757A), found in a person with intellectual disability. Identifying the functional consequences, if any, of such variants allows their potential contribution to pathogenesis to be assessed. Here, we assessed the effect of the GluN2AR586K variant on NMDAR pore properties. Methods: We expressed recombinant NMDARs with and without the GluN2AR586K variant in Xenopus laevis oocytes and in primary cultured mouse neurons, and made electrophysiological recordings assessing Mg2+ block, single-channel conductance, mean open time and current density. Results: The GluN2AR586K variant was not found to influence any of the properties assessed. Conclusions: Our findings suggest it is unlikely that the GluN2AR586K variant contributes to the pathogenesis of neurodevelopmental disorder
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Histopathologic Alterations Associated with Global Gene Expression Due to Chronic Dietary TCDD Exposure in Juvenile Zebrafish
The goal of this project was to investigate the effects and possible developmental disease implication of chronic dietary TCDD exposure on global gene expression anchored to histopathologic analysis in juvenile zebrafish by functional genomic, histopathologic and analytic chemistry methods. Specifically, juvenile zebrafish were fed Biodiet starter with TCDD added at 0, 0.1, 1, 10 and 100 ppb, and fish were sampled following 0, 7, 14, 28 and 42 d after initiation of the exposure. TCDD accumulated in a dose- and time-dependent manner and 100 ppb TCDD caused TCDD accumulation in female (15.49 ppb) and male (18.04 ppb) fish at 28 d post exposure. Dietary TCDD caused multiple lesions in liver, kidney, intestine and ovary of zebrafish and functional dysregulation such as depletion of glycogen in liver, retrobulbar edema, degeneration of nasal neurosensory epithelium, underdevelopment of intestine, and diminution in the fraction of ovarian follicles containing vitellogenic oocytes. Importantly, lesions in nasal epithelium and evidence of endocrine disruption based on alternatively spliced vasa transcripts are two novel and significant results of this study. Microarray gene expression analysis comparing vehicle control to dietary TCDD revealed dysregulated genes involved in pathways associated with cardiac necrosis/cell death, cardiac fibrosis, renal necrosis/cell death and liver necrosis/cell death. These baseline toxicological effects provide evidence for the potential mechanisms of developmental dysfunctions induced by TCDD and vasa as a biomarker for ovarian developmental disruption
Broadband Terahertz Pulse Emission from ZnGeP\u3csub\u3e2\u3c/sub\u3e
Optical rectification is demonstrated in (110)-cut ZnGeP2 (ZGP) providing broadband terahertz (THz) generation. The source is compared to both GaP and GaAs over a wavelength range of 1150 nm to 1600 nm and peak intensity range of 0.5 GW/cm2 to 40 GW/cm2. ZGP peak-to-peak field amplitude is larger than in the other materials due to either lower nonlinear absorption or larger second order nonlinearity. This material is well suited for broadband THz generation across a wide range of infrared excitation wavelengths
SOFIA and ALMA Investigate Magnetic Fields and Gas Structures in Massive Star Formation: The Case of the Masquerading Monster in BYF 73
We present SOFIA+ALMA continuum and spectral-line polarisation data on the
massive molecular cloud BYF 73, revealing important details about the magnetic
field morphology, gas structures, and energetics in this unusual massive star
formation laboratory. The 154m HAWC+ polarisation map finds a highly
organised magnetic field in the densest, inner 0.550.40 pc portion of
the cloud, compared to an unremarkable morphology in the cloud's outer layers.
The 3mm continuum ALMA polarisation data reveal several more structures in the
inner domain, including a pc-long, 500 M "Streamer" around the
central massive protostellar object MIR 2, with magnetic fields mostly parallel
to the east-west Streamer but oriented north-south across MIR 2. The magnetic
field orientation changes from mostly parallel to the column density structures
to mostly perpendicular, at thresholds = 6.610
m, = 2.510 m, and =
427 nT. ALMA also mapped Goldreich-Kylafis polarisation in CO
across the cloud, which traces in both total intensity and polarised flux, a
powerful bipolar outflow from MIR 2 that interacts strongly with the Streamer.
The magnetic field is also strongly aligned along the outflow direction;
energetically, it may dominate the outflow near MIR 2, comprising rare evidence
for a magnetocentrifugal origin to such outflows. A portion of the Streamer may
be in Keplerian rotation around MIR 2, implying a gravitating mass 135050
M for the protostar+disk+envelope; alternatively, these kinematics
can be explained by gas in free fall towards a 95035 M object.
The high accretion rate onto MIR 2 apparently occurs through the Streamer/disk,
and could account for 33% of MIR 2's total luminosity via gravitational
energy release.Comment: 33 pages, 32 figures, accepted by ApJ. Line-Integral Convolution
(LIC) images and movie versions of Figures 3b, 7, and 29 are available at
https://gemelli.spacescience.org/~pbarnes/research/champ/papers
Contrasting Responses to Stress Displayed by Tobacco Overexpressing an Algal Plastid Terminal Oxidase in the Chloroplast
The plastid terminal oxidase (PTOX) â an interfacial diiron carboxylate protein found in the thylakoid membranes of chloroplasts â oxidizes plastoquinol and reduces molecular oxygen to water. It is believed to play a physiologically important role in the response of some plant species to light and salt (NaCl) stress by diverting excess electrons to oxygen thereby protecting photosystem II (PSII) from photodamage. PTOX is therefore a candidate for engineering stress tolerance in crop plants. Previously, we used chloroplast transformation technology to over express PTOX1 from the green alga Chlamydomonas reinhardtii in tobacco (generating line Nt-PTOX-OE). Contrary to expectation, growth of Nt-PTOX-OE plants was more sensitive to light stress. Here we have examined in detail the effects of PTOX1 on photosynthesis in Nt-PTOX-OE tobacco plants grown at two different light intensities. Under âlow lightâ (50 ÎŒmol photons mâ2 sâ1) conditions, Nt-PTOX-OE and WT plants showed similar photosynthetic activities. In contrast, under âhigh lightâ (125 ÎŒmol photons mâ2 sâ1) conditions, Nt-PTOX-OE showed less PSII activity than WT while photosystem I (PSI) activity was unaffected. Nt-PTOX-OE grown under high light also failed to increase the chlorophyll a/b ratio and the maximum rate of CO2 assimilation compared to low-light grown plants, suggesting a defect in acclimation. In contrast, Nt-PTOX-OE plants showed much better germination, root length, and shoot biomass accumulation than WT when exposed to high levels of NaCl and showed better recovery and less chlorophyll bleaching after NaCl stress when grown hydroponically. Overall, our results strengthen the link between PTOX and the resistance of plants to salt stress
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