Search Results - (Author, Cooperation:J. Morison)

2015-09-15

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Animals ; Azepines/pharmacology ; Benzodiazepines/*pharmacology ; Cell Line, Tumor ; Cells, Cultured ; Chromatin/metabolism ; Clone Cells/drug effects/metabolism/pathology ; Drug Resistance, Neoplasm/*drug effects/genetics ; Epigenesis, Genetic ; Gene Expression Regulation, Neoplastic/drug effects ; Genes, myc/genetics ; Hematopoietic Stem Cells/cytology/drug effects/metabolism ; Humans ; Leukemia, Myeloid, Acute/*drug therapy/genetics/*metabolism/pathology ; Mice ; Molecular Targeted Therapy ; Neoplastic Stem Cells/*drug effects/metabolism/*pathology ; Nuclear Proteins/*antagonists & inhibitors/metabolism ; Transcription Factors/*antagonists & inhibitors/metabolism ; Transcription, Genetic/drug effects ; Triazoles/pharmacology ; Wnt Signaling Pathway/drug effects ; beta Catenin/metabolism

2012-01-10

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Arctic Regions ; Atmospheric Pressure ; Canada ; Climate ; Fresh Water/*analysis ; Ice Cover ; Oceans and Seas ; Salinity ; Seawater/analysis ; *Water Movements ; Wind

2018-03-09

Oxford University Press

0015-752X

1464-3626

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

1471-0528

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Electronic Resource

1365-3040

Blackwell Publishing Journal Backfiles 1879-2005

Biology

The global environment is changing with increasing temperature and atmospheric carbon dioxide concentration, [CO2]. Because these two factors are concomitant, and the global [CO2] rise will affect all biomes across the full global range of temperatures, it is essential to review the theory and observations on effects of temperature and [CO2] interactions on plant carbon balance, growth, development, biomass accumulation and yield. Although there are sound theoretical reasons for expecting a larger stimulation of net CO2 assimilation rates by increased [CO2] at higher temperatures, this does not necessarily mean that the pattern of biomass and yield responses to increasing [CO2] and temperature is determined by this response. This paper reviews the interactions between the effects of [CO2] and temperature on plants. There is little unequivocal evidence for large differences in response to [CO2] at different temperatures, as studies are confounded by the different responses of species adapted and acclimated to different temperatures, and the interspecific differences in growth form and development pattern. We conclude by stressing the importance of initiation and expansion of meristems and organs and the balance between assimilate supply and sink activity in determining the growth response to increasing [CO2] and temperature.

Electronic Resource

1365-3040

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Abstract. Two experiments are described which test the normal correlations that arise between stomatal conductance, net CO2 assimilation rate, and intercellular CO2 concentration (Ci), using whole shoots of Commelina communis L. In the first, conductance increased with decreasing Ci, at four different quantum flux densities, such that there was no unique relationship between conductance and quantum flux density or Ci, In the second, conductance increased hyperbolically with increasing quantum flux density while Ci was held constant at 466, 302, and 46 μmiolmol−1, and the response differed at each Ci. In neither experiment was conductance consistently related to net CO2 assimilation rate in the mesophyll. In both experiments high Ci suppressed the response of conductance to light, while there was a large response of conductance to light at low Ci, indicating an interaction between the effects of light and CO2 on stomata. The results show that the parallel responses of assimilation and conductance to light result in constant intercellular CO2 concentrations, and not that stomata maintain a ‘constant Ci’.

Electronic Resource

1365-3040

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Abstract. The response of stomatal conductance to broadband blue and red light was measured in whole shoots of Scots pine and Sitka spruce, two species which have low stomatal sensitivity to CO2. In Scots pine, blue light was more than three times more effective than red light (on an incident quantum basis) in opening stomata, particularly at low quantum flux densities (〈100μmiol m−2 s−1). However, the apparent quantum yield of net CO2 assimilation rate in blue light was only half that in red light. The contrasting effects of red and blue light on conductance and assimilation led to higher intercellular CO2 concentrations (Ci) in blue light (up to 100 μmol mol−1 higher) than in red light. Similar results were obtained with Sitka spruce shoots, though differences in the effectiveness of red and blue light were less marked. In both species, both red and blue light increased conductance in normal and CO2-free air, indicating that neither red nor blue light exert effects through changes in Ci or mesophyll assimilation. However, decreases in Ci caused increases in conductance in both red and blue light, suggesting that these direct effects of light are not wholly independent of CO2.

Electronic Resource

1365-3040

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Native scrub-oak communities in Florida were exposed for three seasons in open top chambers to present atmospheric [CO2] (approx. 350 μmol mol−1) and to high [CO2] (increased by 350 μmol mol−1). Stomatal and photosynthetic acclimation to high [CO2] of the dominant species Quercus myrtifolia was examined by leaf gas exchange of excised shoots. Stomatal conductance (gs) was approximately 40% lower in the high- compared to low-[CO2]-grown plants when measured at their respective growth concentrations. Reciprocal measurements of gs in both high- and low-[CO2]-grown plants showed that there was negative acclimation in the high-[CO2]-grown plants (9–16% reduction in gs when measured at 700 μmol mol−1), but these were small compared to those for net CO2 assimilation rate (A, 21–36%). Stomatal acclimation was more clearly evident in the curve of stomatal response to intercellular [CO2] (ci) which showed a reduction in stomatal sensitivity at low ci in the high-[CO2]-grown plants. Stomatal density showed no change in response to growth in high growth [CO2]. Long-term stomatal and photosynthetic acclimation to growth in high [CO2] did not markedly change the 2·5- to 3-fold increase in gas-exchange-derived water use efficiency caused by high [CO2].

Electronic Resource

1365-3040

Blackwell Publishing Journal Backfiles 1879-2005

Biology

A temperature gradient chamber (TGC) is described which enables elevated CO2 concentrations and a dynamic temperature gradient to be imposed on field crops throughout their life cycle under standard husbandry. Air is circulated through two double-walled polyethylene-covered tunnels connected to a split heat pump system to give a near-linear temperature gradient along each tunnel. Solar energy gain along each tunnel and exchange with outer tunnel air flow contribute to the temperature gradient and also produce diurnal and seasonal temperature fluctuations corresponding to ambient conditions. Mean temperature gradients of between 3 and 5°C have been recorded throughout the growing seasons of crops of lettuce, carrot, cauliflower and winter wheat. Elevated or present CO2 concentrations are maintained in each of two pairs of tunnels throughout the cropping season using pure CO2 injected through motorized needle valves. This system can realistically simulate aspects of the effects of projected future environmental change on crop growth, development and yield, and in particular tin-possible interaction of the effects of increased CO2 and temperature.

Electronic Resource

1365-3040

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Stands of carrot (Daucus carota L.) were grown in the field within polyethylene-covered tunnels at a range of soil temperatures (from a mean of 7·5°C to 10·9°C) at either 348 (SE = 4·7) or 551 (SE = 7·7) μmol mol−1 CO2. The effect of increased atmospheric CO2 concentration on root yield was greater than that on total biomass. At the last harvest (137d from sowing), total biomass was 16% (95% CI = 6%, 27%) greater at 551 than at 348 μmol mol−1 CO2, and 37% (95% CI = 30%, 44%) greater as a result of a 1°C rise in soil temperature. Enrichment with CO2 or a 1°C rise in soil temperature increased root yield by 31% (95% CI = 19%, 45%) and 34% (95% CI = 27%, 42%), respectively, at this harvest. No effect on total biomass or root yield of an interaction between temperature and atmospheric CO2 concentration at 137 DAS was detected. When compared at a given leaf number (seven leaves), CO2 enrichment increased total biomass by 25% and root yields by 80%, but no effect of differences in temperature on plant weights was found. Thus, increases in total biomass and root yield observed in the warmer crops were a result of the effects of temperature on the timing of crop growth and development. Partitioning to the storage roots during early root expansion was greater at 551 than at 348 μmol mol−1 CO2. The root to total weight ratio was unaffected by differences in temperature at 551 μmol mol−1CO2, but was reduced by cooler temperatures at 348 μmol mol−1 CO2. At a given thermal time from sowing, CO2 enrichment increased the leaf area per plant, particularly during early root growth, primarily as a result of an increase in the rate of leaf area expansion, and not an increase in leaf number.

Electronic Resource

1365-2486

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Energy, Environment Protection, Nuclear Power Engineering

Geography

It has been suggested that field experiments which increase UV-B irradiation by a fixed amount irrespective of ambient light conditions (‘square-wave’), may overestimate the response of photosynthesis to UV-B irradiation. In this study, pea (Pisum sativum L.) plants were grown in the field and subjected to a modulated 30% increase in ambient UK summer UV-B radiation (weighted with an erythemal action spectrum) and a mild drought treatment. UV-A and ambient UV control treatments were also studied. There were no significant effects of the UV-B treatment on the in situ CO2 assimilation rate throughout the day or on the light-saturated steady-state photosynthesis. This was confirmed by an absence of UV-B effects on the major components contributing to CO2 assimilation; photosystem II electron transport, ribulose 1,5-bisphosphate regeneration, ribulose 1,5-bisphosphate carboxylase/oxygenase carboxylation, and stomatal conductance. In addition to the absence of an effect on photosynthetic activities, UV-B had no significant impact on plant biomass, leaf area or partitioning. UV-B exposure increased leaf flavonoid content. The UV-A treatment had no observable effect on photosynthesis or productivity. Mild drought resulted in reduced biomass, a change in partitioning away from shoots to roots whilst maintaining leaf area, but had no observable effect on photosynthetic competence. No UV-B and drought treatment interactions were observed on photosynthesis or plant biomass. In conclusion, a 30% increase in UV-B had no effects on photosynthetic performance or productivity in well-watered or droughted pea plants in the field.

Electronic Resource

0047-2441

General, Interdisciplinary

REVIEWS

0047-2441

General, Interdisciplinary

REVIEWS

0047-2441

General, Interdisciplinary

REVIEWS

0047-2441

General, Interdisciplinary

REVIEWS

0029-2397

English, American Studies

History

0029-2397

English, American Studies

History

0029-2397

English, American Studies

History

0168-1923

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Geography

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

Physics

Electronic Resource

1420-9071

Springer Online Journal Archives 1860-2000

Biology

Medicine

Summary Proteolysis, as measured by tyrosine release, was estimated in abdominal and diaphragm muscle of hamsters. There did not appear to be a difference between dystrophic and control hamsters.

Electronic Resource