2,166 research outputs found
Jere Nash Interview with Steve Patterson (Part 1 of 3)
No full textInterview conducted by author Jere Nash with Steve Patterson in the process of writing Mississippi Politics: The Struggle for Power, 1976-2006. Steve Patterson is a former state Democratic Party chairman, Mississippi State Auditor, and unsuccesful candidate for Congress in 1988. Topics discussed include Patterson\u27s background; his work for John Stennis, Cliff Finch, Jimmy Carter, William Winter, and Bill Allain; allegations of Allain\u27s homosexuality; James O. Eastland\u27s decision not to run for reelection in 1978; Bill Waller; Cliff Finch; William F. Winter; Maurice Dantin; Charlie Sullivan; John Bell Williams; John Arthur Eaves and Jimmy Carter\u27s inauguration; Jim Herring; 1979 gubernatorial race; Charles Evers; Charles Pickering versus Bill Allain race for Attorney General; rise of the Republican Party in Mississippi
The autonomic nervous system and chromaffin tissue: Neuroendocrine regulation of catecholamine secretion in non-mammalian vertebrates
No full textIf severe enough, periods of acute stress in animals may be associated with the release of
catecholamine hormones (noradrenaline and adrenaline) into the circulation; a response termed
the acute humoral adrenergic stress response. The release of catecholamines from the sites of
storage, the chromaffin cells, is under neuroendocrine control, the complexity of which appears
to increase through phylogeny. In the agnathans, the earliest branching vertebrates, the
chromaffin cells which are localised predominantly within the heart, lack neuronal innervation
and thus catecholamine secretion in these animals is initiated solely by humoral mechanisms. In
the more advanced teleost fish, the chromaffin cells are largely confined to the walls of the
posterior cardinal vein at the level of the head kidney where they are intermingled with the
steroidogenic interrenal cells. Catecholamine secretion from teleost chromaffin cells is regulated
by a host of cholinergic and non-cholinergic pathways that ensure sufficient redundancy and
flexibility in the secretion process to permit synchronized responses to a myriad of stressors.
The complexity of catecholamine secretion control mechanisms continues through the
amphibians, reptiles and birds although neural (cholinergic) regulation may become increasingly
important in birds. Discrete adrenal glands are present in the non-mammalian tetrapods but
unlike in mammals, there is no clear division of a steroidogenic cortex and a chromaffin cell
enriched medulla. However, in all groups, there is an obvious intermingling of chromaffin and
steroiodogenic cells. The association of the two cell types may be particularly important in the
amphibians and birds because like in mammals, the enzyme catalysing the methylation of
noradrenaline to adrenaline, PNMT, is under the control of the steroid, cortisol
RoMEO Studies 4: An analysis of Journal publishers' Copyright Agreements
No full textThis article is the fourth in a series of six emanating from the UK JISC-funded RoMEO Project (Rights Metadata for Open archiving). It describes an analysis of 80 scholarly journal publishers’ copyright agreements with a particular view to their effect on author self-archiving. 90% of agreements asked for copyright transfer and 69% asked for it prior to refereeing the paper. 75% asked authors to warrant that their work had not been previously published although only two explicitly stated that they viewed self-archiving as prior publication. 28.5% of agreements provided authors with no usage rights over their own paper. Although 42.5% allowed self-archiving in some format, there was no consensus on the conditions under which self-archiving could take place. The article concludes that author-publisher copyright agreements should be reconsidered by a working party representing the needs of both partie
Jere Nash Interview with Steve Guyton
No full textInterview conducted by author Jere Nash with Steve Guyton in the process of writing Mississippi Politics: The Struggle for Power, 1976-2006. Guyton campaigned and worked as a state staff member for several Mississippi congressmen. Topics covered include family background in politics; working as a youth for John Bell Williams\u27 campaign in 1967; student guide for Charlie Griffin\u27s congressional campaign in 1968; student coordinator for Charlie Sullivan\u27s campaign for Lieutenant Governor; Bill Waller; highway legislation and working for the Highway Department; working for Governor Cliff Finch; district director of the Census in 1980; Cliff Finch; William F. Winter; Jamie Whitten issues, working methods, staff; Tennessee-Tombigbee Waterway; Whitten\u27s 1962 race against Frank Smith; Whitten\u27s appropriations for Mississippi universities; Cliff Finch\u27s 1975 campaign race for governor; 1976 Democratic National Convention; George Wallace; Jimmy Carter; working for Mike Parker, Chip Pickering, and Roger Wicker; Ed Cole and his 1988 campaign for chair of the Democratic Party; Roger Wicker\u27s 1994 congressional race; Mike Parker changing parties; Maurice Dantin; Mike Moore; Haley Barbour; unification of the Democratic Party in Mississippi
RoMEO Studies 3: How academics expect to use open-access research papers
No full textThis paper is the third in a series of studies emanating from the UK JISC-funded RoMEO Project (Rights Metadata for Open-archiving). It considers previous studies of the usage of electronic journal articles through a literature survey. It then reports on the results of a survey of 542 academic authors as to how they expected to use open-access research papers. This data is compared with results from the second of the RoMEO Studies series as to how academics wished to protect their open-access research papers. The ways in which academics expect to use open-access works (including activities, restrictions and conditions) are described. It concludes that academics-as-users do not expect to perform all the activities with open-access research papers that academics-as-authors would allow. Thus the rights metadata proposed by the RoMEO Project would appear to meet the usage requirements of most academics
RoMEO Studies 2: How academics wish to protect their open-access research paper
No full textThis paper is the second in a series of studies (see Gadd, E., C. Oppenheim, and S. Probets. RoMEO Studies 1: The impact of copyright ownership on author-self-archiving. Journal of Documentation. 59(3) 243-277) emanating from the UK JISC-funded RoMEO Project (Rights Metadata for Open-archiving). It considers the protection for research papers afforded by UK copyright law, and by e-journal licences. It compares this with the protection required by academic authors for open-access research papers as discovered by the RoMEO academic author survey. The survey used the Open Digital Rights Language (ODRL) as a framework for collecting views from 542 academics as to the permissions, restrictions, and conditions they wanted to assert over their works. Responses from self-archivers and non-archivers are compared. Concludes that most academic authors are primarily interested in preserving their moral rights, and that the protection offered research papers by copyright law is way in excess of that required by most academics. It also raises concerns about the level of protection enforced by e-journal licence agreement
Sex differences in Cognitive Abilities Test scores: a UK national picture
No full textBackground and aims. There is uncertainty about the extent or even existence of sex differences in the mean and variability of reasoning test scores ( Jensen, 1998; Lynn, 1994, ; Mackintosh, 1996). This paper analyses the Cognitive Abilities Test (CAT) scores of a large and representative sample of UK pupils to determine the extent of any sex differences.
Sample. A nationally representative UK sample of over 320,000 school pupils aged 11-12 years was assessed on the CAT (third edition) between September 2001 and August 2003. The CAT includes separate nationally standardized tests for verbal, quantitative, and non-verbal reasoning. The size and recency of the sample is unprecedented in research on this issue.
Methods. The sheer size of the sample ensures that any sex difference will achieve statistical significance. Therefore, effect sizes (d) and variance ratios (VR) are employed to evaluate the magnitude of sex differences in mean scores and in score variability, respectively.
Results. The mean verbal reasoning score for girls was 2.2 standard score points higher than the mean for boys, but only 0.3 standard points in favour of girls for non-verbal reasoning (NVR), and 0.7 points in favour of boys for quantitative reasoning (QR). However, for all three tests there were substantial sex differences in the standard deviation of scores, with greater variance among boys. Boys were over represented relative to girls at both the top and the bottom extremes for all tests, with the exception of the top 10% in verbal reasoning.
Conclusions. Given the small differences in means, explanations for sex differences in wider domains such examination attainment at age 16 need to look beyond conceptions of `ability'. Boys tend to be both the lowest and the highest performers in terms of their reasoning abilities, which warns against the danger of stereotyping boys as low achievers
The Effects of the Heme Oxygenase-1/Carbon Monoxide System on Cardiorespiratory Control in Fish
No full textEndogenously produced carbon monoxide (CO) is an important gaseous signalling molecule which regulates a variety of cardiorespiratory functions. CO is produced in cells by the heme oxygenase (HO) family of proteins by the breakdown of heme into equimolar amounts of CO, bilirubin and Fe2+. My thesis focuses on the hypoxia- and hyperoxia-inducible HO-1/CO system exclusively and aims to provide the first evidence that the HO-1/CO system is involved in cardiorespiratory control in the zebrafish (Danio rerio) and goldfish (Carassius auratus). Overall, I hypothesise that the HO-1/CO system acts as a negative regulator of cardiorespiratory function in fish. Using immunohistochemistry, I was able to characterise the distribution of HO-1 and thus reveal the potential for endogenous CO production (from heme breakdown) in branchial and skin neuroepithelial cells (NECs; putative O2 chemoreceptors) and associated innervation as well as the heart of the developing zebrafish larva. The presence of HO-1 in these structures suggests the likelihood of specific and localized production of CO in fish. To assess the functional significance of the HO-1/CO system in control of cardiorespiratory function, I used pharmacological and gene knock down approaches to diminish HO-1 activity, and presumably endogenous CO production, in adult and larval fish, respectively. The results from these experiments provided evidence that 1) CO has an inhibitory influence on ventilation in goldfish and zebrafish but that its function is temperature- and species-dependent and 2) showed that the HO-1/CO system tonically inhibits cardiac activity in larval zebrafish
Autonomic Control of Cardiac Function
No full textCardiac parasympathetic tone mediates hypoxic bradycardia in fish, however the specific cholinergic mechanisms underlying this response have not been established. In Chapter 2, bradycardia in zebrafish (Danio rerio) larvae experiencing translational knockdown of the M2 muscarinic receptor was either prevented or limited at two different levels of hypoxia (PO2 = 30 or 40 Torr). Also, M2 receptor deficient fish exposed to exogenous procaterol (a presumed β2-adrenergic receptor agonist) had lower heart rates than similarly treated control fish, implying that the β2-adrenergic receptor may have a cardioinhibitory role in this species.
Zebrafish have a single β1-adrenergic receptor (β1AR), but express two distinct β2-adrenergic receptor genes (β2aAR and β2bAR). Zebrafish β1AR deficient larvae described in Chapter 3 had lower resting heart rates than control larvae, which conforms to the stereotypical stimulatory nature of this receptor in the vertebrate heart. However, in larvae where loss of β2a/β2bAR and β1/β2bAR function was combined, heart rate was significantly increased. This confirmed my previous observation that the β2-adrenergic receptor has an inhibitory effect on heart rate in vivo.
Fish release the catecholamines epinephrine and norepinephrine (the endogenous ligands of adrenergic receptors) into the circulation when exposed to hypoxia, if sufficiently severe. Zebrafish have two genes for tyrosine hydroxylase (TH1 and TH2), the rate limiting enzyme for catecholamine synthesis, which requires molecular oxygen as a cofactor. In Chapter 4, zebrafish larvae exposed to hypoxia for 4 days exhibited increased whole body epinephrine and norepinephrine content. TH2, but not TH1, mRNA expression decreased after 2 days of hypoxic exposure.
The results of this thesis provide some of the first data on receptor-specific control of heart rate in fish under normal and hypoxic conditions. It also provides the first observations that catecholamine turnover and the mRNA expression of enzymes required for catecholamine synthesis in larvae are sensitive to hypoxia. Taken together, these data provide an interesting perspective on the balance of adrenergic and cholinergic control of heart rate in zebrafish larvae
Consequences of Gill Remodeling on Na+ Transport in Goldfish, Carassius auratus
No full textGoldfish undergo an adaptive morphological change in their gills involving the reversible growth and loss of a mass of cells (interlamellar cell mass, ILCM) in between the lamellae depending on oxygen demand, which can be altered by the environment or metabolic demands of the individual. The ILCM contributes to decreased passive Na+ efflux across the gill. Active uptake is maintained by the re-distribution of the ionocytes expressing Na+-uptake relevant genes (NHEs and H+-ATPase) to the outer edge of the ILCM where they can establish contact with the external environment and/or lamellar epithelium. This adaptation is thought to be partly responsible for the extreme anoxia tolerance demonstrated by goldfish, which they experience on a seasonal basis living in a pond environment. Hypoxia and hypercapnia are frequently encountered in such freshwater environments and as such, the effect of the ILCM on the capacity for acid-base regulation was evaluated. Differences in the time course of acid excretion to the environment without effect on systemic pH regulation were likely the result of the ILCM
- …
