bluuebunny/crossref_metadata_2025_split huggingface dataset:
CLIMATIC TOLERANCE AND THE DISTRIBUTION OF PLANTS
Authors: GRACE J. 
Published: September 2010

SummaryBoundaries to the distribution of life forms and species often coincide with isometric lines of climatological variables. Prominent examples of this phenomenon are the restriction of megaphanerophytes to areas where the mean temperature of the warmest month does not fall below about 10 °C, and the restriction of species within the British Isles to areas of specific summer or winter warmth. In the interpretation of these patterns, it is important to realise that the climate at plant surfaces may differ appreciably from that of the atmosphere as a whole, to an extent which depends on structural attributes of the vegetation. I n particular, chamaephytes experience a much higher surface temperature than phanerophytes when comparisons are made in bright sunlight and this contributes to their success in mountains. Temperatures of flowers may similarly be elevated. In the British Isles, temperatures in the summer months may be decisive in determining the success of many species, as physiological processes in C3‐plants display near‐linear relationships with temperatures in the range which prevails for most of the time. The life‐cycle of native plants responds to environmental cues in such a way as to synchronize the development of the plant with the succession of seasons. When species are transplanted to different phytogeographical zones, as in forestry and horticulture, they frequently fail because of asynchrony.
Nutrient limitation of the long term response of heather [Calluna vulgaris (L.) Hull] to CO2 enrichment
Authors: WOODIN S. , GRAHAM B. , KILLICK A. , SKIBA U. , CRESSER M. 
Published: September 2010

summaryIn a 27‐month CO2‐enrichment experiment, Calluna vulgaris plants were grown on peat obtained from an upland heath in NE Scotland and given a nutrient supply which mimicked that in precipitation in the area. Three CO2 concentrations were used; ambient, +100ppm and +200ppm. Calluna showed a negative growth response to increased CO2 over the first year of treatment and a positive response by the end of the experiment. Final above–ground biomass was greatest in the enriched CO2, treatments, showing an increase of 30 °0 in + 100ppmCO2. Determination of tissue nutrient concentration, and calculation of total nutrient uptake, demonstrated that nutrient uptake did not increase with increased growth, resulting in significant dilution of elements in leaf tissue. This suggests that, in its typical, nutrient poor habitats, the growth response of Calluna to CO2 will be limited by nutrient deficiency, and will reach a maximum with a relatively small increase in CO, concentration. Flowering was advanced and extremely prolific in +100 ppm CO2 grown plants, but the ecological significance of this is uncertain. The results highlight the need for long term studies of native species on their natural soils, using lower CO2 concentrations than the usual ‘double CO2’.
Spatial variation in ozone resistance of British populations of Plantago major L.
Authors: REILING K. , DAVISON A. W. 
Published: September 2010

summaryThe relative ozone resistance of samples from 28 British Plantago major L. populations, grown from seed, was measured by exposure to charcoal–filtered air or air containing 70 nl I−1 O3 (7 h d−1) over 2 wk. Mean relative growth rate (R) and the allometric root/shoot coefficient (K) were measured. Ozone resistance was expressed as Ores=Rozone/Rcontrol× 100.There were substantial differences between the response of the populations to O3, and the degree of resistance was statistically related to O3 exposure indices and other environmental factors, notably the amount of summer sunshine. This implies that ozone concentrations in parts of Britain are sufficiently high to promote evolution of resistance but alternative explanations are also discussed. Overall, it is concluded that although our results tend to support the hypothesis that O3 resistance in P. major is related primarily to the O3 climate, the question of causation can only be established unequivocally by further experiments. Establishing whether there has been a change in gene frequency needs repeated observation of populations over time.The significance of spatial variation in ozone resistance to the critical levels concept is discussed, particularly in relation to exposure indices.
Evidence for the de novo synthesis of Fructan by enzymes from higher plants: a Reappraisal of the SST/FFT model
Authors: JOHN CAIRNS ANDREW 
Published: September 2010

SUMMARYFor the following reasons, it is argued that the enzymological evidnce is insufficient to sustain the SST/FFT model for fructan systhesis. (i) The original model was speculative. It was formulated without in vitro evidence for the synthesis of inulin of degree of polymerization greater than 3 (DP >3), and without published evidence for the existence of a key enzyme (SST). The model is shown to be untestable in vitro. Subsequently, studies have not domonstrated the synthesis of inulin in vitro, except for trisaccharide. (ii) Most data cited in support of the model are concerned with the synthesis of the smallest fructans (trisaccharides) by crude enzyme extracts. Much of these data can be explained in terms of artifactual fructosyl trasfer by invertase, a common contaminant of plant enzyme preparations. (iii) There are few reports of the de novo enzymatic synthesis of fructan DP >3 in plants. Where it has been reported, it was eatalyzed by crude or partially purified enzymes. Hence the number and properties of the enzymes involved is not known, providing no evidence for distinct SST and FFT enzymes. (iv) Assays for FFT require preformed fructan substates. FFT transfers fructose between preformed fructan molecules without net synthesis of fructan. Hence measurement of FFT is not evidence for net fructan synthesis. (v) Invertase can mimic the FFT reaction. (vi) The enzymes of fructan biosynthesis have not been purified and characterized in any plant species. Where functional separation of SST and FFT activities has been achieved. Reconstitution experiments have not been performed demostrating de novo fructan synthesis by the recombined activities. (vi) The SST/FFT model explains the synthesis of the linear β‐2,1‐linked homologous series of fructans. The model is inadequate to explain the synthesis of other linkage types and branched fructans. (vii) There is no demonstration of the enzymatic de novo synthesis of the full complement of tissue fructan by SST/FFT or otherwise, for any plant species.Although were is a substantial body of evidence which is consistent with the SST/FFT model, it is concluded that the hypothesis is flawed and that the enzymological data from all species do not validate the model. Enzyme systems from grasses are described which overcome some of these difficulties.
The kinetic analysis of fructan biosynthesis in excised leaves of Lolium temulentum L.
Authors: SIMS I.M. , MORGAN R. , POLLOCK C. J. 
Published: September 2010

SUMMARYExcised leaves of Lolium temulentum L. were fed 1CO. at 99% isotopic abundance in order to study the kinetics of incorporation of photosynthetically fixed carbon into different fructans and to determine the pathways of synthesis between sucrose and high‐molecular‐weight fructan. Following 6 h exposure to CO2 of detached and illuminated leaves, analysis of the accumulation of I‐keatose, 6–kestose and neokestose, and of the pattern of labelling observed in these isomers, suggested that they were each formed directly from sucrose at different rates. Similarly, the data suggested thai the tetrasaccharide isomers were formed directly from their trisaccharide precursors. Changes in the concentration of 13C both in the total water‐soluble component of the leaves and the fructan pool after 20h exposure to 13Co2 suggested that there was a continual turnover of frunctosyl residues. The formation of trisaccharides From sucrose and subsequent frunctosyl transfer to oligo‐ and polysaccharides of progressively higher molecular weight was consistent with a direct precursor product relationship. The stable concenttation of sucrose observed in leaves between 14 h and 48 h after excision indicated that fructan metabolism in L. temulentum may serve to regulate the sucrose content of the tissue.
Yield advantage of a ‘slow‐’over a‘fast‐’respiring population of Lolium perenne cv. S23 depends on plant density
Authors: KRAUS EDWIN , AYDEMIR YILDIZ , DUIN SANDRA , KOLLÖFFEL CHRIS , LAMBERS HANS 
Published: September 2010

SUMMARYSelected populations of Lolium perenne have previously been shown to have contrasting rates of mature leaf dark respiration and yield. Plants were now grown in high‐ and in tow‐density stands. We were able to reproduce the differences in yield for the high‐density‐grown plants. However the low‐density‐grown plants did not differ in yield and so (the correlation between respiration and yield is not apparent, It is concluded that the difference in respiration rate is not the most important factor determining yield with these populations.
Mustards, mustard oils and mycorrhizas
Authors: PAUL SCHREINER R. , KOIDE ROGER T. 
Published: September 2010

SUMMARYIntact, living routs of Brassica Kaber (DC.) Wheeler and Brassica nigra. L. (Erassicaeeae) were inhibitory to the germination of spores of the mycorrhizal fungi Glomus intraradices Schenck & Smith and Glowns etunivatum Becker & Gerd. Roots from two similarly non‐mycotrophic species, spinach (Chenopodiaceae) and Amaranthus retroflexus L. (Amaranthaceae). had no effect on the germination of spores of G. intraradices. The roots of two out of three mycotrophic species examined were stimulatory to germination of C intraradices. To test the hypothesis that the inhibition of VAM fungus spore‐ germination by the roots of B. kaber and B. nigra was due to isothiocyanates (mustard oils), lysine arginine and gtutathione Mere added separately to the nutrient solutions applied to the plants. These compounds were expected to react with isothiocyartates released into tlu1 rrtizosphcre. In one experiment, lysine, tirKiniiK‐ arid glutarhione rcsfored the‐ avrminauim of G. intraradices to control levels for B. kaber and nearly to the control levels for B. nigra. In a second experiment employing lower concentrations of lysinc. jtryinitie and glutathimie, irraination of spates of G. efttmeantai in the presence of B. kabcr roots was restored nearly to the levels of controls. In the same experiment, these treatments had no significant effects on spore germination in the presence of B. nigra roots. Lysine and arginine also protected spores of G. etunicatum from in vitro reactions of B, nigra root glucosinolate; extract with myrosinase. The involvement of isothiocyanates in the resistance of mustards to VAM Fungi is discussed.
Plant macrofossils from the Lower Channel sediments at Marsworth, Buckinghamshire, UK
Authors: FIELD MICHAEL H. 
Published: September 2010

SUMMARYResults from studies of sediments in the Pitstone No. 3 quarry near Marsworth, Buckinghamshire, England have raised the issue of a possible temperate episode between the Ipswichian and Hoxnian stages of the British Pleistocene. Plant macrofossils were studied from the fossiliferous Lower Channel muds, in which the probable temperate episode was represented, in an attempt to reconstruct the contemporary vegetation and to make inferences about the environment in which these sediments were deposited. Taxa recovered represented a treeless habitat with low growing herbs dominant. The assemblages may provide evidence of conditions cooler than those in southern England today. Only travertine incorporated into the Lower Channel muds and travertine made it impossible to determine the precise age of these sediments. The travertine could represent an additional temperate event between the Ipswichian and Hoxnian Stages. Alternatively, the travertine may have been deposited during the Hoxnian Stage and then reworked into the Lower Channel muds. This could have occurred at the beginning of the cold Wolstonian Stage or in an interstadial within this stage.
Survival and recovery of perennial forage grasses under prolonged Mediterranean drought: I. Growth, death, water relations and solute content in herbage and stubble
Authors: VOLAIRE FLORENCE , THOMAS HENRY , LELIÈVRE FRANÇOIS 
Published: September 2010

Swards of Dactylis glomerata cultivars (cvs) KM2 and Lutetia and of Lolium perenne cvs Aurora and Vigor were grown under full irrigation or prolonged summer drought (80 d) in a field experiment in the South of France.After irrigation was withheld, leaf extension rates of all cvs fell by 90% within 9–12 d, and rapid scorching of laminae followed. Tiller mortality at the end of the drought was very different in the cocksfoot cvs (4% for KM2 and 76% for Lutetia) and intermediate (41%) for both ryegrass cvs. Following re‐watering, rates of herbage regrowth were closely correlated with tiller survival. Measured minerals contributed c. 0·52 MPa to osmotic potential in all treatments, whereas water‐soluble carbohydrates (WSC) contributed 0·25 MPa under irrigation and 0·46 MPa during drought.There was no systematic difference between the two species for summer survival under severe drought, but large differences between the cocksfoot cvs. The traits most strongly associated with superior survival were: (a) a deep root system and greater water uptake at depth; (b) low water and osmotic potentials in surviving laminae, i.e. better tolerance to dehydration; (c) large pool‐size of WSC reserves (fructans having degree of polymerization >4) in entire tiller bases (stubble); (d) low accumulation of proline in stubble; (e) rapid nitrogen uptake after rewatering.
Evolution of the type III secretion system and its effectors in plant–microbe interactions
Authors: McCann Honour C. , Guttman David S. 
Published: September 2010

SummaryMany bacterial plant pathogens require the type III secretion system (T3SS) and its effector proteins (T3SEs) to invade and extract nutrients from their hosts successfully. While the molecular function of this system is being studied intensively, we know comparatively little about the evolutionary and ecological pressures governing its fate over time, and even less about the detailed mechanisms underlying and driving complex T3SS‐mediated coevolutionary dynamics. In this review we summarize our current understanding of how host–pathogen interactions evolve, with a particular focus on the T3SS of bacterial plant pathogens. We explore the evolutionary origins of the T3SS relative to the closely related flagellar system, and investigate the evolutionary pressures on this secretion and translocation apparatus. We examine the evolutionary forces acting on T3SEs, and compare the support for vertical descent with modification of these virulence‐associated systems (pathoadaptation) vs horizontal gene transfer. We address the evolutionary origins of T3SEs from the perspective of both the evolutionary mechanisms that generate new effectors, and the mobile elements that may be the source of novel genetic material. Finally, we propose a number of questions raised by these studies, which may serve to guide our thinking about these complex processes.

Contents

Summary
33

I.
Introduction
34

II.
The type III secretion system and the plant immune system
34

III.
The evolution of the type III secretion apparatus
36

IV.
The evolution of type III secreted effectors
39

V.
The origin of type III secreted effectors
41

VI.
Conclusion and future directions
43

Acknowledgements
44

References
44
Development and physiology of the brown alga Ectocarpus siliculosus: two centuries of research
Authors: Charrier Bénédicte , Coelho Susana M. , Le Bail Aude , Tonon Thierry , Michel Gurvan , Potin Philippe , Kloareg Bernard , Boyen Catherine , Peters Akira F. , Cock J. Mark 
Published: September 2010

SummaryBrown algae share several important features with land plants, such as their photoautotrophic nature and their cellulose‐containing wall, but the two groups are distantly related from an evolutionary point of view. The heterokont phylum, to which the brown algae belong, is a eukaryotic crown group that is phylogenetically distinct not only from the green lineage, but also from the red algae and the opisthokont phylum (fungi and animals). As a result of this independent evolutionary history, the brown algae exhibit many novel features and, moreover, have evolved complex multicellular development independently of the other major groups already mentioned. In 2004, a consortium of laboratories, including the Station Biologique in Roscoff and Genoscope, initiated a project to sequence the genome of Ectocarpus siliculosus, a small filamentous brown alga that is found in temperate, coastal environments throughout the globe. The E. siliculosus genome, which is currently being annotated, is expected to be the first completely characterized genome of a multicellular alga. In this review we look back over two centuries of work on this brown alga and highlight the advances that have led to the choice of E. siliculosus as a genomic and genetic model organism for the brown algae.

Contents

Summary
319

I.
Introduction
320

II.
Diversity and taxonomy, distribution and ecology
321

III.
Development
321

IV.
Metabolism
326

V.
Interactions with the environment
327

VI.
Conclusion
328

Acknowledgements
329

References
329
Replication of an association of variation in the FOXO3A gene with human longevity using both case–control and longitudinal data
Authors: Soerensen Mette , Dato Serena , Christensen Kaare , McGue Matt , Stevnsner Tinna , Bohr Vilhelm A. , Christiansen Lene 
Published: September 2010

SummaryGenetic variation in FOXO3A has previously been associated with human longevity. Studies published so far have been case–control studies and hence vulnerable to bias introduced by cohort effects. In this study we extended the previous findings in the cohorts of oldest old Danes (the Danish 1905 cohort, N = 1089) and middle‐aged Danes (N = 736), applying a longitudinal study design as well as the case–control study design. Fifteen SNPs were chosen in order to cover the known common variation in FOXO3A. Comparing SNP frequencies in the oldest old with middle‐aged individuals, we found association (after correction for multiple testing) of eight SNPs; 4 (rs13217795, rs2764264, rs479744, and rs9400239) previously reported to be associated with longevity and four novel SNPs (rs12206094, rs13220810, rs7762395, and rs9486902 (corrected P‐values 0.001–0.044). Moreover, we found association of the haplotypes TAC and CAC of rs9486902, rs10499051, and rs12206094 (corrected P‐values: 0.01–0.03) with longevity. Finally, we here present data applying a longitudinal study design; when using follow‐up survival data on the oldest old in a longitudinal analysis, we found no SNPs to remain significant after the correction for multiple testing (Bonferroni correction). Hence, our results support and extent the proposed role of FOXO3A as a candidate longevity gene for survival from younger ages to old age, yet not during old age.
Chronic Care Improvement in Primary Care: Evaluation of an Integrated Pay‐for‐Performance and Practice‐Based Care Coordination Program among Elderly Patients with Diabetes
Authors: Fagan Peter J. , Schuster Alyson B. , Boyd Cynthia , Marsteller Jill A. , Griswold Michael , Murphy Shannon M. E. , Dunbar Linda , Forrest Christopher B. 
Published: September 2010

Objective.To examine the effects of an intervention comprising (1) a practice‐based care coordination program, (2) augmented by pay for performance (P4P) for meeting quality targets, and (3) complemented by a third‐party disease management on quality of care and resource use for older adults with diabetes.Data Sources/Study Setting.Claims files of a managed care organization (MCO) for 20,943 adults aged 65 and older with diabetes receiving care in Alabama, Tennessee, or Texas, from January 2004 to March 2007.Study Design.A quasi‐experimental, longitudinal study in which pre‐ and postdata from 1,587 patients in nine intervention primary care practices were evaluated against 19,356 patients in MCO comparison practices (>900). Five incentivized quality measures, two nonincentivized measures, and two resource‐use measures were investigated. We examined trends and changes in trends from baseline to follow‐up, contrasting intervention and comparison group member results.Principal Findings.Quality of care generally improved for both groups during the study period. Only slight differences were seen between the intervention and comparison group trends and changes in trends over time.Conclusions.This study did not generate evidence supporting a beneficial effect of an on‐site care coordination intervention augmented by P4P and complemented by third‐party disease management on diabetes quality or resource use.
Improving Timely Childhood Immunizations through Pay for Performance in Medicaid‐Managed Care
Authors: Chien Alyna T. , Li Zhonghe , Rosenthal Meredith B. 
Published: September 2010

Objective. To evaluate the impact of a “piece‐rate” pay‐for‐performance (P4P) program aimed at rewarding up‐to‐date immunization delivery to 2‐year‐olds according to the recommended series.Data Sources/Study Setting. Plan‐level data from New York State's Quality Assurance Reporting Requirement and claims data from Hudson Health Plan for 2003–2007. In 2003 Hudson Health Plan, a not‐for‐profit Medicaid‐focused managed care plan, introduced a U.S.$200 bonus payment for each fully immunized 2‐year‐old and provided administrative supports for identifying children who may need immunization. This represented a potential bonus of 15–25 percent above base reimbursement for eligible 2‐year‐olds.Study Design. Case‐comparison and interrupted times series.Principal Findings. Immunization rates within Hudson Health Plan rose at a significantly, albeit modestly, higher rate than the robust secular trend noted among comparison health plans. Supplementary analyses suggest that there was no significant change in preexisting disparities during the study period, and that children with chronic conditions have significantly greater odds of being fully immunized during the entire study period.Conclusions. This study suggests that a piece‐rate P4P program with appropriate administrative supports can be effective at improving childhood immunization rates.
Piroxicam and carboplatin as a combination treatment of canine oral non‐tonsillar squamous cell carcinoma: a pilot study and a literature review of a canine model of human head and neck squamous cell carcinoma
Authors: De Vos J. P. , Burm A. G. D. , Focker A. P. , Boschloo H. , Karsijns M. , Van Der Waal I. 
Published: September 2010

AbstractResults of the treatment with a combination of carboplatin and piroxicam in seven dogs with advanced non‐tonsillar oral squamous cell carcinoma (SCC) were retrospectively analysed. This multi‐agent protocol was well tolerated by all dogs and resulted in a complete regression of the tumour without additional surgery in four of seven patients. Additional surgery was necessary to remove a metastatic lymph node in one dog and residual tumour in a second dog, which achieved a partial response following medical therapy. Median follow‐up for all the dogs was 534 days, while the time‐to‐recurrence, time‐to‐progression and overall survival for this group of patients have not yet been reached. Our study, although limited in number of animals, suggests that this multiagent approach is a useful treatment option for oral non‐tonsillarSCC in dogs and warrants wider application.