Search Results - (Author, Cooperation:K. Edwards)

2012-05-15

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

*Genetic Research/ethics/legislation & jurisprudence ; *Genomics ; Humans ; International Cooperation ; Internet ; Translational Medical Research

2016-02-27

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

2018-11-03

The American Society for Biochemistry and Molecular Biology (ASBMB)

0021-9258

1083-351X

Biology

Chemistry and Pharmacology

2018-01-03

The Society of Nuclear Medicine (SNM)

0022-3123

Medicine

1475-2743

Blackwell Publishing Journal Backfiles 1879-2005

Geosciences

Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Abstract. To allow land planners and managers to assess erosion under alternative management practices a model has been developed. It is based on the universal soil loss equation but uses subfactors for crop cover and management. Readily available agronomic data and field expert opinion were used in formulating the method. Locally-derived data are used to validate the model which is then applied to agricultural systems in New South Wales, ranking the relative erosion hazard associated with crop and land management practices.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

We describe methods for automating the control and tracking of states within or near a chaotic attractor. The methods are applied in a simulation using a recently developed model of thermal pulse combustion as the dynamical system. The controlled state is automatically tracked while a parameter is slowly changed well beyond the usual flame-out point where the chaotic attractor ceases to exist because of boundary crisis. A learning strategy based on simple neural networks is applied to map-based proportional feedback control algorithms both with and without a recursive term. Adaptive recursive proportional feedback is found to track farther beyond the crisis (flame-out) boundary than does the adaptive non-recursive map-based control. We also found that a continuous-time feedback proportional to the derivative of a system variable will stabilize and track an unstable fixed point near the chaotic attractor. The positive results suggest that a pulse combustor, and other nonlinear systems, may be suitably controlled to reduce undesirable cyclic variability and extend their useful operating range. © 1995 American Institute of Physics.

Electronic Resource

1365-2826

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Prolactin receptor (PRL-R) mRNA transcript level was quantified in the choroid plexus (ChP) of a naturally biparental hamster, Phodopus campbelli, and its otherwise similar, yet nonpaternal, sibling species, Phodopus sungorus. Pair-housed males and females on the day before the birth of their first litter (G17), the day after birth (L1), lactation day 5 (L5), and unpaired animals that were sexually naïve, were tested. PRL-R mRNA transcript level relative to total RNA, was evaluated by reverse transcriptase-polymerase chain reaction using primers common to the long- and short-form of the PRL-R in Phodopus. In the ChP, a region implicated in prolactin transport into the central nervous system, females had the expected increase in PRL-R mRNA transcript from dioestrus to L5, consistent with known actions of prolactin. As predicted, males and females of the biparental species were similar, although PRL-R mRNA in naïve males was higher than in dioestrus females. Males of the two species also differed as predicted. PRL-R mRNA transcript levels were higher in the biparental males. In addition, P. campbelli males had low PRL-R mRNA at G17 compared to L5. By contrast, non-paternal P. sungorus males had elevated PRL-R mRNA transcript levels on G17 relative to unpaired males. We conclude that PRL-R mRNA in the ChP is differentially regulated before and after birth in a paternal and a nonpaternal male.

Electronic Resource

1365-2826

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

To assess whether the mediobasal hypothalamus (MBH) is necessary for photoperiodic control of oestrous cycles and prolactin secretion, we tested intact female Syrian hamsters (controls) and those that had sustained unilateral or bilateral lesions of the MBH. All hamsters displayed 4-day oestrous cycles postoperatively in the long-day photoperiod (14 h light/day); control females and those with unilateral MBH damage ceased to undergo oestrous cycles approximately 8 weeks after transfer to a short-day photocycle (10 h light/day), whereas 12 of 15 females with bilateral MBH lesions continued to generate 4-day oestrous cycles throughout 22 weeks in short days. Serum prolactin concentrations were either undetectable or low in all hamsters 8 or 14 weeks after the transfer to short-day lengths, but increased above long-day baseline values by week 22. We conclude that melatonin-binding sites in the MBH mediate suppression of oestrous cycles but not prolactin secretion by short-day lengths; recovery of prolactin secretion in females during prolonged exposure to short-day lengths reflects development of refractoriness to melatonin in a substrate distinct from the MBH. These findings suggest that separate neural pathways mediate photoperiodic control of gonadotropin and prolactin secretion in female hamsters.

Electronic Resource

1365-2826

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Short days induce multiple changes in reproductive and immune function in Siberian hamsters. Short-day reproductive inhibition in this species is regulated by an endogenous timing mechanism; after approximately 20 weeks in short days, neuroendocrine refractoriness to short-day patterns of melatonin develops, triggering spontaneous recrudescence of the reproductive system. It is unknown whether analogous mechanisms control immune function, or if photoperiodic changes in immune function are masked by prevailing photoperiod. In Experiment 1, 3 weeks of exposure to long days was not sufficient to induce long-day-like enhancement of in vitro lymphocyte proliferation in short-day adapted male Siberian hamsters. Experiment 2 tested the hypothesis that immunological photorefractoriness is induced by prolonged exposure to short days. Adult male hamsters were gonadectomized or sham-gonadectomized and housed in long (14 h light/day) or short (10 h light/day) photoperiods for 12, 32 or 40 weeks. Somatic and reproductive regression occurred after 12 weeks in short days, and spontaneous recrudescence was complete after 32–40 weeks in short days, indicative of somatic and reproductive photorefractoriness. In gonad-intact hamsters, 12 weeks of exposure to short days decreased the number of circulating granulocytes and increased the number of B-like lymphocytes. After 32 weeks in short days, these measures were restored to long-day values, indicative of photorefractoriness; castration eliminated these effects of photoperiod. In both intact and castrated hamsters, in vitro proliferation of splenic lymphocytes was inhibited by 12 weeks of exposure to short days. After 40 weeks in short days lymphocyte proliferation was restored to long-day values in intact hamsters, but remained suppressed in castrated hamsters. These results suggest that short-day-induced inhibition of lymphocyte function does not depend on gonadal regression, but that spontaneous recrudescence of this measure is dependent on gonadal recrudescence. In Experiment 3, in vitro treatment with melatonin enhanced basal proliferation of lymphocytes from male hamsters exposed to short days for 12 weeks, but had no effect on lymphocytes of photorefractory hamsters or long-day control hamsters. Lymphocytes of castrated hamsters were unresponsive to in vitro melatonin, suggesting that photoperiodic changes in gonadal hormone secretion may be required to activate mechanisms which permit differential responsiveness to melatonin depending on phase in the annual reproductive cycle. Together, these data indicate that, similar to the reproductive system, the immune system of male Siberian hamsters exhibits refractoriness to short days.

Electronic Resource

1365-3040

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Electronic Resource

1747-6593

Blackwell Publishing Journal Backfiles 1879-2005

Energy, Environment Protection, Nuclear Power Engineering

This paper describes the experimental design and engineering of the largest contemporary survey of domestic water consumption in the UK. Results are presented for the first full year of data collection and are discussed in terms of explanatory variables, reliability and usefulness. Significant findings include (a) the range of per capita consumption, (b) relationships to explanatory variables, (c) components of consumption including legitimate night flows, and (d) the contributions of specific domestic appliances.

Electronic Resource

0005-7894

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Psychology

Electronic Resource

1440-1681

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

1. The intestinal transport of l-prolyl-l-hydroxyproline (10 mmol/l) was investigated in rat small gut loops in vivo under pentobarbitone anaesthesia. Osmolality of test solutions was adjusted to eliminate any positive effect of solvent drag on disappearance of solutes from the lumen.2. l-Leucylglycine and β-alanyl-l-histidine (carnosine), representative members of two distinctly different dipeptide transport groups previously delineated, were tested for competitive action on l-prolyl-l-hydroxyproline uptake at ten times equimolar concentration (100 mmol/l), but were found to have no effect on the carrier system.3. l-prolyl-l-hydroxyproline uptake was markedly blocked by other l-prolyl dipeptides, indicating that they shared a common carrier system. Disappearance of l-prolyl-l-hydroxyproline from the gut lumen was reduced from 48% 15 min-1 10 cm-1 (control, containing 70 mmol/l mannitol) to 11% or 20% in the presence of l-prolylglycine (100 mmol/l) or l-prolyl-l-leucine (25 mmol/l), respectively.4. It was concluded that at least three separate dipeptide carrier protein systems exist in the rat small gut, the disappearance of l-prolyl-l-hydroxyproline from the gut lumen being inhibited by two other l-prolyl dipeptides but not by l-leucyl or β-alanyl dipeptides.

Electronic Resource

1440-1681

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

1. The effect of changing sodium intake for 2 weeks was studied. Twelve nor-motensive subjects and five patients with mild essential hypertension were given two different levels of sodium intake for 2 weeks.2. Overall there was no significant rise in blood pressure but all patients with hypertension had a rise in blood pressure as they went from a low to a high sodium intake.3. Plasma sodium was not altered but red cell sodium concentration was higher on the high sodium intake. This effect was observed in both normotensive and hypertensive people.4. Alterations observed in cell sodium concentration provide support for the hypothesis that increased dietary intake of sodium may induce hypertension by causing changes in cellular transport systems.

Electronic Resource

0022-0973

Education

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] The ATS-6 radio beacon experiment8 provides a method of estimating integrated net ionospheric-protonospheric fluxes on a continuous basis from the temporal changes in protono-spheric content. The receiving station at Aberystwyth (52.42N, 4.05W) for transmissions from the ATS-6 satellite ...

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] The ATS-6 radio beacon experiment6 carried out at Aberystwyth (52.42N, 4.05W), while the geostationary satellite was stationed at 35E longitude,, allowed estimates to be made of both the plasmapheric tojal electron content (7VT) and the ionospheric Faraday electron content (N) to sufficient ...

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] Some 530 recordings of passes of the ionospheric beacon satellite BE-B (1964-64A) taken at Aberystwyth (52.42N, 4.05 W) were selected from the available records for the years 1966 to 1968 inclusive. The sample analysed comprised those records which showed irregular Faraday fading rates, indicating ...

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] The stratigraphy of the Teindland profile as described by FitzPatrick may be summarised as follows. The section showed at the top a semi-podsol in 2?2.4 m of sandy till and outwash gravel which overlay a fossil iron podsol developed in fluvioglacial outwash. The upper part of the buried soil which ...

Electronic Resource

0277-5395

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Sociology

Electronic Resource