330 research outputs found
Altered chemokine expression in the spinal cord and brain contributes to differential interleukin-1 beta-induced neutrophil recruitment
No full textThe pattern of neutrophil recruitment that accompanies inflammation in the CNS depends on the site of injury and the stage of development. The adult brain parenchyma is refractory to neutrophil recruitment and associated damage as compared to the spinal cord or juvenile brain. Using quantitative Taqman RT–PCR and enzyme-liked immunosorbent assay (ELISA), we compared mRNA and protein expression of the rat neutrophil chemoattractant chemokines (CINC) in spinal cord and brain of adult and juvenile rats to identify possible association with the observed differences in neutrophil recruitment. Interleukin-1? (IL-1?) injection resulted in up-regulated chemokine expression in both brain and spinal cord. CINC-3 mRNA was elevated above CINC-1 and CINC-2?, with expression levels for each higher in spinal cord than in brain. By ELISA, IL-1? induced greater CINC-1 and CINC-2? expression compared to CINC-3, with higher protein levels in spinal cord than in brain. In the juvenile brain, significantly higher levels of CINC-2? protein were observed in response to IL-1? injection than in the adult brain following an equivalent challenge. Correspondingly, neutrophil recruitment was observed in the juvenile brain and adult spinal cord, but not in the adult brain. No expression of CINC-2? mRNA was detected. Thus differential chemokine induction may contribute to variations in neutrophil recruitment in during development and between the different CNS compartments
Differential induction of interleukin-1 beta and tumour necrosis factor-alpha may account for specific patterns of leukocyte recruitment in the brain
No full textIn peripheral tissue, IL-1beta has been shown to induce TNFalpha expression and vice versa, resulting in mixed neutrophil and mononuclear cell recruitment to the site of injury. This has led to the concept of crosstalk in peripheral cytokine signalling pathways. In the brain parenchyma, however, restricted patterns of leukocyte recruitment following the focal injection of pro-inflammatory agents into the brain are observed. This study investigates the expression of the principal pro_inflammatory cytokines-IL-1beta and TNFalpha-in the brain after IL-1beta, TNFalpha, NMDA or endotoxin injection into the brain parenchyma of rats. Each of these agents gives rise to a distinct pattern of acute leukocyte recruitment at 24 h. We found that IL-1beta induces de novo synthesis of additional IL-1beta but not TNFalpha, as determined by RT-PCR and ELISA, and TNFalpha does not induce either itself or IL-1beta. Injection of NMDA results in IL-1beta, but not TNFalpha up-regulation. Injection of IL-1beta or NMDA is associated with neutrophil recruitment whereas injection of TNFalpha is associated with mononuclear cell recruitment. Following injection of endotoxin, both TNFalpha and IL-1beta levels are elevated and neutrophils and mononuclear cells are recruited to the brain. These data suggest that the signalling pathways that are present in the periphery are modified in the brain and that differential induction of TNFalpha and IL-1beta may have a role in the atypical pattern of leukocyte recruitment observed in the brain
The forgotten first: John MacCormick's 'Dùn-Àluinn'
No full textThe first Gaelic novel, John MacCormick's Dùn-Àluinn, no an t-Oighre 'na Dhìobarach, was serialised in the People's Journal in 1910 before being published in its entirety in 1912. Within a year of the publication of Dùn-Àluinn as a novel the second Gaelic novel, Angus Robertson's An t-Ogha Mòr, appeared in print, underlining the renaissance which Gaelic literature was experiencing. Both novels, while remarked upon by contemporaries and by general studies of Gaelic literature, have been all but ignored to date, with no criticism or analysis of either having been published. The main aim of this article is to offer some general comments about MacCormick's Dùn-Àluinn and thus to open up both the novel and indeed other early twentieth-century Gaelic writers and their work to further scrutiny. Consideration will be given to the author himself, the contemporary Gaelic literary scene and finally some of the more interesting aspects of the novel itself
W. G. Sebald’s theology: A heretic mounts the pulpit
No full textThis essay traces a number of ways in which theological matters mark the work of the German author and critic W. G. Sebald (1944–2001). It concentrates on Sebald’s relatively neglected critical writing belonging to the first two decades of his career (c. 1969–1989). Founded on original archival research and a close examination of Sebald’s religious background and reading, this essay argues that, contrary to the author’s disavowals and his critics’ disinterest, theological concerns determined his own critical perspective in far-reaching ways. This essay demonstrates how Sebald considered humankind to be essentially guilt-laden, with severely limited hopes for salvation. This view gave the impetus to, and prescribed the limits of, Sebald’s critical mode, which combines the wilful eccentricity of the heretic with the moral fervour of the preacher
Calcium signaling genes in association with altitude-induced pulmonary hypertension in Angus cattle
No full text2019 Fall.Includes bibliographical references.This research used multi-omics technology (i.e., RNA-seq, qPCR for gene expression, SNP discovery and validation) to understand the influence of a particular subset genes on altitude-induced pulmonary hypertension susceptibility in Angus cattle. Three research aims were established to test the hypothesis that calcium-related genes may be associated with pulmonary hypertension in beef cattle. Data and samples utilized for the research came from the Colorado State University Beef Improvement Center Angus herd managed at 2,150 m of altitude. Transcriptome data from 6 tissues and 14 hypertensive and normotensive Angus steers were utilized for differential expression and pathway analyses. The objectives of the first aim were to: 1) to estimate and identify differentially expressed genes from RNA-Seq and pathway analyses, and 2) select putative candidate genes to analyze with qPCR (gene expression level). The largest number of DE genes was revealed in aorta (n = 631) and right ventricle (n = 2,183) samples. Top canonical pathways related to calcium signaling or utilization included: synaptic long-term depression, signaling by Rho family GTPases, and oxidative phosphorylation. Genes regulating calcium availability and utilization were expressed differently (log2 fold change > 0.589, < -0.589; P < 0.05) in Angus cattle with and without pulmonary hypertension. Isolated RNA from cardiac muscle (n = 9) and control muscle (n = 2) tissues from hypertensive and normotensive Angus steers were utilized to estimate gene expression using quantitative reverse transcription PCR in the candidate genes from Chapter 3. The objectives of this chapter were: 1) to establish the most appropriate reference genes in cardiac muscle tissues, and 2) to estimate and validated relative gene expression of calcium-related genes in cardiac muscle tissues using qPCR methods. Differences (P < 0.0055) among hypertensive and normotensive steers were estimated for right papillary muscle and right cardiac ventricle tissues (top, middle, and bottom) in candidate genes: ASIC2, EDN1, NOX4, PLA2G4A, RCAN1, and THBS4. Results of the current study validate the expression differences previously established of genes that regulate the availability and utilization of calcium with PH status in Angus steers at high altitude. Variant detection and association analyses were completed with 2 sets of available -omics data to identify opportunities for development of selection tools for reduced susceptibility to PH. The objectives of the third aim were to: 1) detect single nucleotide polymorphisms (SNP) in the transcriptome of 6 tissues, and 2) identify functional consequences of those variants associated with validated candidate genes from qPCR analyses. Pooled Angus sample analysis revealed 68 SNP in the 6 candidate genes: ASIC2, EDN1, NOX4, PLA2G4A, RCAN1, and THBS4. Thirty-eight SNP were revealed in the hypertensive group and 8 SNP in the normotensive steer group. Ten of the 68 identified SNP are utilized on large density commercially available bovine SNP chips (Illumina BovineHD BeadChip; GeneSeek Genomic Profiler HD; GeneSeek Genomic Profiler HDv2; Affymetrix Axiom Bovine). Analysis of transcriptome data identified SNP within genes regulating calcium availability and utilization, enhancing our understanding of sequence polymorphisms that may be involved in regulating pulmonary hypertension in Angus cattle raised at high altitude. These SNP are available for additional validation and potential use in genetic improvement programs
Central nervous system injury triggers hepatic CC and CXC chemokine expression that is associated with leukocyte mobilization and recruitment to both the central nervous system and the liver
No full textThe administration of interleukin-1ß to the brain induces hepatic CXC chemokine synthesis, which increases neutrophil levels in the blood, liver, and brain. We now show that such hepatic response is not restricted to the CXC chemokines. CCL-2, a CC chemokine, was released by the liver in response to a tumor necrosis factor (TNF)- challenge to the brain and boosted monocyte levels. Furthermore, a clinically relevant compression injury to the spinal cord triggered hepatic chemokine expression of both types. After a spinal cord injury, elevated CCL-2 and CXCL-1 mRNA and protein were observed in the liver by TaqMan reverse transcriptase-polymerase chain reaction and enzyme-linked immunosorbent assay as early as 2 to 4 hours. Simultaneously, we observed elevated levels of these chemokines and circulating leukocyte populations in the blood. Leukocytes were recruited to the liver at this early stage, whereas at the site of challenge in the central nervous system, few were observed until 24 hours. Artificial elevation of blood CCL-2 triggered dose-dependent monocyte mobilization in the blood and enhanced monocyte recruitment to the brain after TNF- challenge. Attenuation of hepatic CCL-2 production with corticosteroids resulted in reduced monocyte levels after the TNF- challenge. Thus, combined production of CC and CXC hepatic chemokines appears to amplify the central nervous system response to injury
Soul and body, sound and hearty: getting to know Bishop MacEachern
No full textThe examination of a letter written by first Roman Catholic bishop of Prince Edward Island, the Scottish Highlander Angus Bernard MacEachern, written in 1832 to a former parishoner Angus Walker in which the bishop engages in clever code switching from English to Scottish Gaelic and back in order to deliver a message which could only be understood, if intercepted, by another bilingual Scottish Gaelic/English speaker. The paper reveals the historical setting of the 1832 letter and goes on to examine closely the passages of Scottish Gaelic: their meaning in terms of social commentary, their non-standard orthography which provide clues to mainland Scottish dialect variants evidenced by the same, and the descriptions of parishoners encrypted in the author's first language.Source type: Print(0
Pulmonary arterial pressure in Angus cattle: environmental influences and relationship with growth and carcass traits
No full text2017 Summer.Includes bibliographical references.Right-side heart failure (RHF) resulting from hypoxia induced pulmonary hypertension is most commonly observed in cattle located at high elevations, but has been observed in some feedlot cattle residing at low elevations as well. Beef cattle producers typically use pulmonary arterial pressure (PAP) observations to predict an animal's susceptibility to RHF. The objective of this this study was to investigate the effect of elevation on PAP measures, and to evaluate the relationship between PAP, growth traits, and carcass traits in Angus cattle. The first study utilized PAP and elevation data obtained from the American Angus Association (AAA, n = 4,511), Colorado State University Beef Improvement Center (n = 5,433), and Dr. Timothy Holt DVM (n = 4,821). A univariate analysis of PAP as used to obtain elevation solutions to be input to a polynomial regression to determine high versus low elevation (1,620 m). Then a bi-variate analysis was performed to evaluate the genetic relationship between PAP observations obtained at high elevations as well as low elevations. Results from this study indicate that PAP observations obtained at any elevation can be considered the same trait with a genetic correlation of (0.83 ± 0.15). The second study utilized data obtained from AAA (n = 4,509) which included PAP, growth, and carcass traits. Multivariate analyses of PAP and growth traits, as well as PAP and carcass ultrasound traits were used to obtain estimates of heritability and genetic correlations. Results from these analyses indicated that there are moderate genetic correlations between PAP and maternal birth weight (0.55 ± 0.12) as well as PAP and ultrasound ribeye area (0.24 ± 0.12). These results suggested that selection for increased growth and muscling in cattle could consequently increase PAP observations
The investigation into an algorithm based on wavelet basis functions for the spatial and frequency decomposition of arbitrary signals.
No full textThesis (Ph.D.)-University of Natal, Durban, 1994.The research was directed toward the viability of an O(n) algorithm which could decompose
an arbitrary signal (sound, vibration etc.) into its time-frequency space. The well known
Fourier Transform uses sine and cosine functions (having infinite support on t) as
orthonormal basis functions to decompose a signal i(t) in the time domain to F(w) in the
frequency . domain, where the Fourier coefficients F(w) are the contributions of each
frequency in the original signal. Due to the non-local support of these basis functions, a
signal containing a sharp localised transient does not have localised coefficients, but rather
coefficients that decay slowly. Another problem is that the coefficients F(w) do not convey
any time information. The windowed Fourier Transform, or short-time Fourier Transform,
does attempt to resolve the latter, but has had limited success.
Wavelets are basis functions, usually mutually orthonormal, having finite support in t and
are therefore spatially local. Using non-orthogonal wavelets, the Dominant Scale
Transform (DST) designed by the author, decomposes a signal into its approximate time-frequency
space. The associated Dominant Scale Algorithm (DSA) has O(n) complexity
and is integer-based. These two characteristics make the DSA extremely efficient. The
thesis also investigates the problem of converting a music signal into it's equivalent music
score. The old problem of speech recognition is also examined. The results obtained from
the DST are shown to be consistent with those of other authors who have utilised other
methods. The resulting DST coefficients are shown to render the DST particularly useful in
speech segmentation (silence regions, voiced speech regions, and frication). Moreover, the
Spectrogram Dominant Scale Transform (SDST), formulated from the DST, was shown to
approximate the Fourier coefficients over fixed time intervals within vowel regions of
human speech
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