17 results on '"Rich, Sarah"'
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2. Feasibility of a theoretically grounded, multicomponent, physiotherapy intervention aiming to promote autonomous motivation to adopt and maintain physical activity in patients with lower-limb osteoarthritis: protocol for a single-arm trial.
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Willett M, Rushton A, Stephens G, Fenton S, Rich S, Greig C, and Duda J
- Abstract
Background: Lower-limb osteoarthritis (OA) causes high levels of pain and disability in adults over 45 years of age. Adopting and maintaining appropriate levels of physical activity (PA) can help patients with lower-limb OA self-manage their symptoms and reduce the likelihood of developing secondary noncommunicable diseases. However, patients with lower-limb OA are less active than people without musculoskeletal pain. This single-arm feasibility trial seeks to determine the feasibility and acceptability of a complex multicomponent physiotherapy behaviour change intervention that aims to aid patients with lower-limb OA to adopt and maintain optimal levels of PA., Methods: This trial will be conducted at one site in a National Health Service physiotherapy outpatient setting in the West Midlands of England. Up to thirty-five participants with lower-limb OA will be recruited to receive a physiotherapy intervention of six sessions that aims to optimise their PA levels during phases of behavioural change: adoption, routine formation and maintenance. The intervention is underpinned by self-determination theory (and other motivational frameworks) and seeks to foster a motivationally optimal (empowering) treatment environment and implement behaviour change techniques (BCTs) that target PA behaviours across the three phases of the intervention. Physiotherapists (n = 5-6) will receive training in the why and how of developing a more empowering motivational environment and the delivery of the intervention BCTs. Participants will complete patient-reported and performance-based outcome measures at baseline and 3-month (to reflect behavioural adoption) and 6-month (maintenance) post-baseline. Feasibility and acceptability will be primarily assessed through semi-structured interviews (purposively recruiting participants) and focus groups (inviting all physiotherapists and research staff). Further evaluation will include descriptive analysis of recruitment rates, loss of follow-up and intervention fidelity., Discussion: A novel complex, multicomponent theoretical physiotherapy behaviour change intervention that aims to create a more empowering motivational treatment environment to assist patients with lower-limb OA to adopt and maintain optimal PA levels has been developed. Testing the feasibility and acceptability of the intervention and its associated physiotherapist training and related trial procedures is required to determine whether a full-scale parallel group (1:1) randomised controlled trial to evaluate the interventions effectiveness in clinical practice is indicated., Trial Registration: Trial register: International Standard Randomised Controlled Trial identification number: ISRCTN12002764 . Date of registration: 15 February 2022., (© 2023. The Author(s).)
- Published
- 2023
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3. Heart Rate Changes Before, During, and After Treadmill Walking Exercise in Normal Dogs.
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Shull SA, Rich SK, Gillette RL, and Manfredi JM
- Abstract
In dogs, changes in heart rate (HR) can reflect conditioning, fear, anticipation, and pain; however, these are not routinely assessed in veterinary rehabilitation patients. Knowing the expected HR changes during rehabilitation exercises can guide protocols and can optimize post-operative therapy. The primary objectives of the study were to assess HR in dogs undergoing treadmill exercise (TE) during the walk and to compare the three collection techniques of HR, namely, auscultation, a HR monitor (HR MONITOR), and a Holter monitor (HOLTER). We hypothesized that the HR would increase by 20% during TE, that HR taken after TE would not be the same as the HR during TE, and that all methods of measurement would have good agreement. HR was recorded in all methods simultaneously, in eight adult healthy large breed dogs during rest (REST), immediately before TE (PRE), during TE (WALK), and 15 and 60 s after TE (POST-15, POST-60). Statistical analyses included Spearman and Pearson correlations, Bland-Altman analyses, and a repeated measures ANOVA with Sidak's post-hoc test (significant at value of p < 0.05). Increased HR was reflected in TE during WALK, and elevations in HR during WALK were not reflected in POST timepoints. Auscultation was also not possible during WALK. Significant moderate-to-strong correlations existed among all monitoring options at each of the timepoints ( rho range = 0.5-0.9, p < 0.05). There were no correlations between peak HR and age or weight. The main limitation of this study is that only healthy and large breed dogs were used. Both monitors captured the increase in HR during exercise and could guide TE regimens to minimize patient risk of injury and to maximize training effectiveness., Competing Interests: RG was employed by company Sportsvet Veterinary Consulting Services. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Shull, Rich, Gillette and Manfredi.)
- Published
- 2021
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4. Root phenotypes of young wheat plants grown in controlled environments show inconsistent correlation with mature root traits in the field.
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Rich SM, Christopher J, Richards R, and Watt M
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- Environment, Controlled, Genotype, Phenotype, Plant Roots, Triticum genetics
- Abstract
Using a field to lab approach, mature deep-rooting traits in wheat were correlated to root phenotypes measured on young plants from controlled conditions. Mature deep-rooting root traits of 20 wheat genotypes at maturity were established via coring in three field trials across 2 years. Field traits were correlated to phenotypes expressed by the 20 genotypes after growth in four commonly used lab screens: (i) soil tubes for root emergence, elongation, length, and branching at four ages to 34 days after sowing (DAS); (ii) paper pouches 7 DAS and (iii) agar chambers for primary root (PR) number and angles at 8 DAS; and (iv) soil baskets for PR and nodal root (NR) number and angle at 42 DAS. Correlations between lab and field root traits (r2=0.45-0.73) were highly inconsistent, with many traits uncorrelated and no one lab phenotype correlating similarly across three field experiments. Phenotypes most positively associated with deep field roots were: longest PR and NR axiles from the soil tube screen at 20 DAS; and narrow PR angle and wide NR angle from soil baskets at 42 DAS. Paper and agar PR angles were positively and significantly correlated to each other, but only wide outer PRs in the paper screen correlated positively to shallower field root traits. NR phenotypes in soil baskets were not predicted by PR phenotypes in any screen, suggesting independent developmental controls and value in measuring both root types in lab screens. Strong temporal and edaphic effects on mature root traits, and a lack of understanding of root trait changes during plant development, are major challenges in creating controlled-environment root screens for mature root traits in the field., (© The Author(s) 2020. Published by Oxford University Press on behalf of the Society for Experimental Biology.)
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- 2020
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5. Correction to: Harmonizing national abortion and pregnancy prevention laws and policies for sexual violence survivors with the Maputo Protocol: proceedings of a 2016 regional technical meeting in sub-Saharan Africa.
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Thompson J, Undie CC, Amin A, Johnson BR, Khosla R, Ouedraogo L, Nkurunziza T, Rich S, Westley E, Garcia M, Birungi H, and Askew I
- Abstract
[This corrects the article DOI: 10.1186/s12919-018-0101-5.].
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- 2018
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6. The 2018 Inter-agency field manual on reproductive health in humanitarian settings: revising the global standards.
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Foster AM, Evans DP, Garcia M, Knaster S, Krause S, McGinn T, Rich S, Shah M, Tappis H, and Wheeler E
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- Awareness, Capacity Building, Contraception methods, Cooperative Behavior, Female, Human Rights, Humans, Knowledge, Maternal-Child Health Services economics, Maternal-Child Health Services supply & distribution, Policy, Relief Work economics, Reproductive Health Services economics, Reproductive Health Services supply & distribution, Sex Education, Women's Health, Maternal-Child Health Services organization & administration, Refugees, Relief Work organization & administration, Reproductive Health Services organization & administration, United Nations
- Abstract
Since the 1990s, the Inter-agency field manual on reproductive health in humanitarian settings (IAFM) has provided authoritative guidance on reproductive health service provision during different phases of complex humanitarian emergencies. In 2018, the Inter-Agency Working Group on Reproductive Health in Crises will release a new edition of this global resource. In this article, we describe the collaborative and inter-sectoral revision process and highlight major changes in the 2018 IAFM. Key revisions to the manual include repositioning unintended pregnancy prevention within and explicitly incorporating safe abortion care into the Minimum Initial Service Package (MISP) chapter, which outlines a set of priority activities to be implemented at the outset of a humanitarian crisis; stronger guidance on the transition from the MISP to comprehensive sexual and reproductive health services; and the addition of a logistics chapter. In addition, the IAFM now places greater and more consistent emphasis on human rights principles and obligations, gender-based violence, and the linkages between maternal and newborn health, and incorporates a diverse range of field examples. We conclude this article with an outline of plans for releasing the 2018 IAFM and facilitating uptake by those working in refugee, crisis, conflict, and emergency settings.
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- 2017
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7. Wheats developed for high yield on stored soil moisture have deep vigorous root systems.
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Rich SM, Wasson AP, Richards RA, Katore T, Prashar R, Chowdhary R, Saxena DC, Mamrutha HM, Zwart A, Misra SC, Sai Prasad SV, Chatrath R, Christopher J, and Watt M
- Abstract
Many rainfed wheat production systems are reliant on stored soil water for some or all of their water inputs. Selection and breeding for root traits could result in a yield benefit; however, breeding for root traits has traditionally been avoided due to the difficulty of phenotyping mature root systems, limited understanding of root system development and function, and the strong influence of environmental conditions on the phenotype of the mature root system. This paper outlines an international field selection program for beneficial root traits at maturity using soil coring in India and Australia. In the rainfed areas of India, wheat is sown at the end of the monsoon into hot soils with a quickly receding soil water profile; in season water inputs are minimal. We hypothesised that wheat selected and bred for high yield under these conditions would have deep, vigorous root systems, allowing them to access and utilise the stored soil water at depth around anthesis and grain-filling when surface layers were dry. The Indian trials resulted in 49 lines being sent to Australia for phenotyping. These lines were ranked against 41 high yielding Australian lines. Variation was observed for deep root traits e.g. in eastern Australia in 2012, maximum depth ranged from 118.8 to 146.3cm. There was significant variation for root traits between sites and years, however, several Indian genotypes were identified that consistently ranked highly across sites and years for deep rooting traits.
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- 2016
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8. Soil conditions and cereal root system architecture: review and considerations for linking Darwin and Weaver.
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Rich SM and Watt M
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- Agriculture, Edible Grain growth & development, Edible Grain physiology, Environment, Controlled, Humans, Plant Roots growth & development, Plant Roots physiology, Tropism physiology, Edible Grain anatomy & histology, Plant Roots anatomy & histology, Soil
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Charles Darwin founded root system architecture research in 1880 when he described a root bending with gravity. Curving, elongating, and branching are the three cellular processes in roots that underlie root architecture. Together they determine the distribution of roots through soil and time, and hence the plants' access to water and nutrients, and anchorage. Most knowledge of these cellular processes comes from seedlings of the model dicotyledon, Arabidopsis, grown in soil-less conditions with single treatments. Root systems in the field, however, face multiple stimuli that interact with the plant genetics to result in the root system architecture. Here we review how soil conditions influence root system architecture; focusing on cereals. Cereals provide half of human calories, and their root systems differ from those of dicotyledons. We find that few controlled-environment studies combine more than one soil stimulus and, those that do, highlight the complexity of responses. Most studies are conducted on seedling roots; those on adult roots generally show low correlations to seedling studies. Few field studies report root and soil conditions. Until technologies are available to track root architecture in the field, soil analyses combined with knowledge of the effects of factors on elongation and gravitropism could be ranked to better predict the interaction between genetics and environment (G×E) for a given crop. Understanding how soil conditions regulate root architecture can be effectively used to design soil management and plant genetics that best exploit synergies from G×E of roots.
- Published
- 2013
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9. Shoot atmospheric contact is of little importance to aeration of deeper portions of the wetland plant Meionectes brownii; submerged organs mainly acquire O2 from the water column or produce it endogenously in underwater photosynthesis.
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Rich SM, Pedersen O, Ludwig M, and Colmer TD
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- Cell Respiration, Circadian Rhythm, Diffusion, Magnoliopsida anatomy & histology, Plant Stems anatomy & histology, Porosity, Wetlands, Aquatic Organisms physiology, Magnoliopsida physiology, Oxygen physiology, Photosynthesis, Plant Stems physiology
- Abstract
Partial shoot submergence is considered less stressful than complete submergence of plants, as aerial contact allows gas exchange with the atmosphere. In situ microelectrode studies of the wetland plant Meionectes brownii showed that O(2) dynamics in the submerged stems and aquatic roots of partially submerged plants were similar to those of completely submerged plants, with internal O(2) concentrations in both organs dropping to less than 5 kPa by dawn regardless of submergence level. The anatomy at the nodes and the relationship between tissue porosity and rates of O(2) diffusion through stems were studied. Stem internodes contained aerenchyma and had mean gas space area of 17.7% per cross section, whereas nodes had 8.2%, but nodal porosity was highly variable, some nodes had very low porosity or were completely occluded (ca. 23% of nodes sampled). The cumulative effect of these low porosity nodes would have impeded internal O(2) movement down stems. Therefore, regardless of the presence of an aerial connection, the deeper portions of submerged organs sourced most of their O(2) via inwards diffusion from the water column during the night, and endogenous production in underwater photosynthesis during the daytime., (© 2012 Blackwell Publishing Ltd.)
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- 2013
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10. Aquatic adventitious root development in partially and completely submerged wetland plants Cotula coronopifolia and Meionectes brownii.
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Rich SM, Ludwig M, and Colmer TD
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- Aquatic Organisms growth & development, Asteraceae metabolism, Light, Asteraceae growth & development, Chlorophyll metabolism, Photosynthesis physiology, Plant Leaves metabolism, Plant Roots growth & development, Plant Roots metabolism, Plant Stems metabolism, Wetlands
- Abstract
Background and Aims: A common response of wetland plants to flooding is the formation of aquatic adventitious roots. Observations of aquatic root growth are widespread; however, controlled studies of aquatic roots of terrestrial herbaceous species are scarce. Submergence tolerance and aquatic root growth and physiology were evaluated in two herbaceous, perennial wetland species Cotula coronopifolia and Meionectes brownii., Methods: Plants were raised in large pots with 'sediment' roots in nutrient solution and then placed into individual tanks and shoots were left in air or submerged (completely or partially). The effects on growth of aquatic root removal, and of light availability to submerged plant organs, were evaluated. Responses of aquatic root porosity, chlorophyll and underwater photosynthesis, were studied., Key Results: Both species tolerated 4 weeks of complete or partial submergence. Extensive, photosynthetically active, aquatic adventitious roots grew from submerged stems and contributed up to 90 % of the total root dry mass. When aquatic roots were pruned, completely submerged plants grew less and had lower stem and leaf chlorophyll a, as compared with controls with intact roots. Roots exposed to the lowest PAR (daily mean 4.7 ± 2.4 µmol m(-2) s(-1)) under water contained less chlorophyll, but there was no difference in aquatic root biomass after 4 weeks, regardless of light availability in the water column (high PAR was available to all emergent shoots)., Conclusions: Both M. brownii and C. coronopifolia responded to submergence with growth of aquatic adventitious roots, which essentially replaced the existing sediment root system. These aquatic roots contained chlorophyll and were photosynthetically active. Removal of aquatic roots had negative effects on plant growth during partial and complete submergence.
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- 2012
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11. In situ O2 dynamics in submerged Isoetes australis: varied leaf gas permeability influences underwater photosynthesis and internal O2.
- Author
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Pedersen O, Pulido C, Rich SM, and Colmer TD
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- Acclimatization, Air, Australia, Biomass, Citric Acid metabolism, Ecosystem, Immersion, Malates metabolism, Partial Pressure, Permeability, Plant Transpiration, Ferns physiology, Oxygen metabolism, Photosynthesis physiology, Plant Leaves physiology, Water physiology
- Abstract
A unique type of vernal pool are those formed on granite outcrops, as the substrate prevents percolation so that water accumulates in depressions when precipitation exceeds evaporation. The O(2) dynamics of small, shallow vernal pools with dense populations of Isoetes australis were studied in situ, and the potential importance of the achlorophyllous leaf bases to underwater net photosynthesis (P(N)) and radial O(2) loss to sediments is highlighted. O(2) microelectrodes were used in situ to monitor pO(2) in leaves, shallow sediments, and water in four vernal pools. The role of the achlorophyllous leaf bases in gas exchange was evaluated in laboratory studies of underwater P(N), loss of tissue water, radial O(2) loss, and light microscopy. Tissue and sediment pO(2) showed large diurnal amplitudes and internal O(2) was more similar to sediment pO(2) than water pO(2). In early afternoon, sediment pO(2) was often higher than tissue pO(2) and although sediment O(2) declined substantially during the night, it did not become anoxic. The achlorophyllous leaf bases were 34% of the surface area of the shoots, and enhanced by 2.5-fold rates of underwater P(N) by the green portions, presumably by increasing the surface area for CO(2) entry. In addition, these leaf bases would contribute to loss of O(2) to the surrounding sediments. Numerous species of isoetids, seagrasses, and rosette-forming wetland plants have a large proportion of the leaf buried in sediments and this study indicates that the white achlorophyllous leaf bases may act as an important area of entry for CO(2), or exit for O(2), with the surrounding sediment., (© 2011 The Author(s).)
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- 2011
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12. Crassulacean acid metabolism enhances underwater photosynthesis and diminishes photorespiration in the aquatic plant Isoetes australis.
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Pedersen O, Rich SM, Pulido C, Cawthray GR, and Colmer TD
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- Air, Aquatic Organisms physiology, Australia, Bryophyta metabolism, Bryophyta physiology, Bryophyta radiation effects, Carbon Dioxide pharmacology, Cell Respiration drug effects, Cell Respiration radiation effects, Geologic Sediments, Malates metabolism, Oxygen pharmacology, Photosynthesis radiation effects, Plant Leaves drug effects, Plant Leaves physiology, Plant Leaves radiation effects, Time Factors, Titrimetry, Aquatic Organisms drug effects, Aquatic Organisms radiation effects, Bryophyta drug effects, Light, Photosynthesis drug effects, Water
- Abstract
• Underwater photosynthesis by aquatic plants is often limited by low availability of CO(2), and photorespiration can be high. Some aquatic plants utilize crassulacean acid metabolism (CAM) photosynthesis. The benefits of CAM for increased underwater photosynthesis and suppression of photorespiration were evaluated for Isoetes australis, a submerged plant that inhabits shallow temporary rock pools. • Leaves high or low in malate were evaluated for underwater net photosynthesis and apparent photorespiration at a range of CO(2) and O(2) concentrations. • CAM activity was indicated by 9.7-fold higher leaf malate at dawn, compared with at dusk, and also by changes in the titratable acidity (μmol H(+) equivalents) of leaves. Leaves high in malate showed not only higher underwater net photosynthesis at low external CO(2) concentrations but also lower apparent photorespiration. Suppression by CAM of apparent photorespiration was evident at a range of O(2) concentrations, including values below air equilibrium. At a high O(2) concentration of 2.2-fold the atmospheric equilibrium concentration, net photosynthesis was reduced substantially and, although it remained positive in leaves containing high malate concentrations, it became negative in those low in malate. • CAM in aquatic plants enables higher rates of underwater net photosynthesis over large O(2) and CO(2) concentration ranges in floodwaters, via increased CO(2) fixation and suppression of photorespiration., (© 2010 The Authors. New Phytologist © 2010 New Phytologist Trust.)
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- 2011
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13. Aquatic adventitious roots of the wetland plant Meionectes brownii can photosynthesize: implications for root function during flooding.
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Rich SM, Ludwig M, Pedersen O, and Colmer TD
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- Aquatic Organisms growth & development, Aquatic Organisms radiation effects, Biomass, Chlorophyll metabolism, Floods, Light, Organ Specificity radiation effects, Oxygen metabolism, Partial Pressure, Photosynthesis radiation effects, Plant Roots growth & development, Plant Roots radiation effects, Saxifragaceae growth & development, Saxifragaceae radiation effects, Aquatic Organisms physiology, Photosynthesis physiology, Plant Roots physiology, Saxifragaceae physiology, Wetlands
- Abstract
• Many wetland plants produce aquatic adventitious roots from submerged stems. Aquatic roots can form chloroplasts, potentially producing endogenous carbon and oxygen. Here, aquatic root photosynthesis was evaluated in the wetland plant Meionectes brownii, which grows extensive stem-borne aquatic roots during submergence. • Underwater photosynthetic light and CO(2) response curves were determined for aquatic-adapted leaves, stems and aquatic roots of M. brownii. Oxygen microelectrode and (14)CO(2)-uptake experiments determined shoot inputs of O(2) and photosynthate into aquatic roots. • Aquatic adventitious roots contain a complete photosynthetic pathway. Underwater photosynthetic rates are similar to those of stems, with a maximum net photosynthetic rate (P(max)) of 0.38 μmol O(2) m(-2) s(-1); however, this is c. 30-fold lower than that of aquatic-adapted leaves. Under saturating light with 300 mmol m(-3) dissolved CO(2), aquatic roots fix carbon at 0.016 μmol CO(2) g(-1) DM s(-1). Illuminated aquatic roots do not rely on exogenous inputs of O(2). • The photosynthetic ability of aquatic roots presumably offers an advantage to submerged M. brownii as aquatic roots, unlike sediment roots, need little O(2) and carbohydrate inputs from the shoot when illuminated., (© 2010 The Authors. New Phytologist © 2010 New Phytologist Trust.)
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- 2011
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14. Oxygen and glucose deprivation in an organotypic hippocampal slice model of the developing rat brain: the effects on N-methyl-D-aspartate subunit composition.
- Author
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Wise-Faberowski L, Robinson PN, Rich S, and Warner DS
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- Animals, Animals, Newborn, Cell Death physiology, Cell Hypoxia physiology, Glucose metabolism, Hippocampus pathology, Organ Culture Techniques, Protein Subunits biosynthesis, Rats, Rats, Sprague-Dawley, Receptors, N-Methyl-D-Aspartate biosynthesis, Glucose deficiency, Hippocampus growth & development, Hippocampus metabolism, Neurogenesis physiology, Oxygen metabolism, Protein Subunits metabolism, Receptors, N-Methyl-D-Aspartate metabolism
- Abstract
Background: Organotypic hippocampal slices (OHS) are commonly used to screen for neuroprotective effects of pharmacological agents relevant to pediatric brain injury. The importance of donor rat pup age and N-methyl-D-aspartate (NMDA) receptor subunit composition have not been addressed. In this study, we evaluated the age-dependent effect of oxygen-glucose deprivation (OGD) in the developing rat brain and determined whether OGD modulates the NMDA receptor subunit composition., Methods: OHS were prepared from rat pups on postnatal days (PND) 4, 7, 14, and 21 and cultured 7 days in vitro. The slices were exposed to OGD for durations of 5-60 min. After 24 and 72 h, OHS survival and NMDA subunit composition were assessed., Results: Cell death was evident in OHS prepared from PND 14 and 21 rat pups (P < 0.001) with OGD durations of 5 and 10 min, respectively. In OHS prepared from PND7 rat pups, neurodegeneration was not evident until 20 min OGD (P < 0.001). Exposure to OGD in OHS prepared from PND4 and PND7 rat pups was associated with a transition in the NMDA receptor subunit composition from NR2B predominant to NR2A predominant subunit composition., Conclusions: This in vitro neonatal rat pup investigation using OHS supports both an age and an NMDA receptor subunit composition-dependent relationship between OGD and neuronal cell death.
- Published
- 2009
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15. Surviving floods: leaf gas films improve O₂ and CO₂ exchange, root aeration, and growth of completely submerged rice.
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Pedersen O, Rich SM, and Colmer TD
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- Acclimatization, Cell Respiration, Darkness, Diffusion, Gases metabolism, Light, Oryza metabolism, Oryza physiology, Oxidative Stress, Photosynthesis, Plant Leaves growth & development, Plant Leaves metabolism, Plant Roots growth & development, Plant Roots metabolism, Plant Shoots growth & development, Plant Shoots metabolism, Plant Shoots physiology, Plant Transpiration, Porosity, Water metabolism, Carbon Dioxide metabolism, Floods, Oryza growth & development, Oxygen metabolism, Plant Leaves physiology, Plant Roots physiology
- Abstract
When completely submerged, the leaves of some species retain a surface gas film. Leaf gas films on submerged plants have recently been termed 'plant plastrons', analogous with the plastrons of aquatic insects. In aquatic insects, surface gas layers (i.e. plastrons) enlarge the gas-water interface to promote O₂ uptake when under water; however, the function of leaf gas films has rarely been considered. The present study demonstrates that gas films on leaves of completely submerged rice facilitate entry of O₂ from floodwaters when in darkness and CO₂ entry when in light. O₂ microprofiles showed that the improved gas exchange was not caused by differences in diffusive boundary layers adjacent to submerged leaves with or without gas films; instead, reduced resistance to gas exchange was probably due to the enlarged water-gas interface (cf. aquatic insects). When gas films were removed artificially, underwater net photosynthesis declined to only 20% of the rate with gas films present, such that, after 7 days of complete submergence, tissue sugar levels declined, and both shoot and root growth were reduced. Internal aeration of roots in anoxic medium, when shoots were in aerobic floodwater in darkness or when in light, was improved considerably when leaf gas films were present. Thus, leaf gas films contribute to the submergence tolerance of rice, in addition to those traits already recognized, such as the shoot-elongation response, aerenchyma and metabolic adjustments to O₂ deficiency and oxidative stress., (© 2009 The Authors. Journal compilation © 2009 Blackwell Publishing Ltd.)
- Published
- 2009
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16. A molecular phylogeny of the orange subfamily(Rutaceae: Aurantioideae) using nine cpDNA sequences.
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Bayer RJ, Mabberley DJ, Morton C, Miller CH, Sharma IK, Pfeil BE, Rich S, Hitchcock R, and Sykes S
- Abstract
The breeding of new, high-quality citrus cultivars depends on dependable information about the relationships of taxa within the tribe Citreae; therefore, it is important to have a well-supported phylogeny of the relationships between species not only to advance breeding strategies, but also to advance conservation strategies for the wild taxa. The recent history of the systematics of Citrus (Rutaceae: Aurantioideae) and its allies, in the context of Rutaceae taxonomy as a whole, is reviewed. The most recent classification is tested using nine cpDNA sequence regions in representatives of all genera of the subfam. Aurantioideae (save Limnocitrus) and numerous species and hybrids referred to Citrus s.l. Aurantioideae are confirmed as monophyletic. Within Aurantioideae, tribe Clauseneae are not monophyletic unless Murraya s.s. and Merrillia are removed to Aurantieae. Within tribe Aurantieae, the three traditionally recognized subtribes are not monophyletic. Triphasiinae is not monophyletic unless Oxanthera is returned to Citrus (Citrinae). Balsamocitrinae is polyphyletic. Feroniella, traditionally considered allied closely to Limonia (=Feronia), is shown to be nested in Citrus. The proposed congenericity of Severinia and Atalantia is confirmed. The most recent circumscription of Citrus is strongly supported by this analysis, with hybrids appearing with their putative maternal parents. The genus was resolved into two clades, one comprising wild species from New Guinea, Australia, and New Caledonia (formerly Clymenia, Eremocitrus, Microcitrus, Oxanthera), but surprisingly also Citrus medica, traditionally believed to be native in India. The second clade is largely from the Asian mainland (including species formerly referred to Fortunella and Poncirus).
- Published
- 2009
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17. Photosynthesis in aquatic adventitious roots of the halophytic stem-succulent Tecticornia pergranulata (formerly Halosarcia pergranulata).
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Rich SM, Ludwig M, and Colmer TD
- Subjects
- Amaranthaceae metabolism, Blotting, Western, Carbohydrates analysis, Chlorophyll metabolism, Plant Proteins metabolism, Plant Roots metabolism, Plant Stems metabolism, Amaranthaceae physiology, Photosynthesis, Plant Roots physiology, Plant Stems physiology
- Abstract
In flood-tolerant species, a common response to inundation is growth of adventitious roots into the water column. The capacity for these roots to become photosynthetically active has received scant attention. The experiments presented here show the aquatic adventitious roots of the flood-tolerant, halophytic stem-succulent, Tecticornia pergranulata (subfamily Salicornioideae, Chenopodiaceae) are photosynthetic and quantify for the first time the photosynthetic capacity of aquatic roots for a terrestrial species. Fluorescence microscopy was used to determine the presence of chloroplasts within cells of aquatic roots. Net O(2) production by excised aquatic roots, when underwater, was measured with varying light and CO(2) regimes; the apparent maximum capacity (P(max)) for underwater net photosynthesis in aquatic roots was 0.45 micromol O(2) m(-2) s(-1). The photosynthetic potential of these roots was supported by the immunolocalization of PsbA, the major protein of photosystem II, and ribulose-1-5-bisphosphate carboxylase/oxygenase (Rubisco) in root protein extracts. Chlorophyllous aquatic roots of T. pergranulata are photosynthetically active, and such activity is a previously unrecognized source of O(2), and potentially carbohydrates, in flooded and submerged plants.
- Published
- 2008
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