bluuebunny/crossref_metadata_2025_split huggingface dataset:
Real-time assessment of seed dormancy and seedling growth for weed management
Authors: Forcella Frank 
Published: September 2008

AbstractComputer software called WeedCast was developed to simulate weed seed dormancy, timing of seedling emergence, and seedling height growth in crop environments in real-time and using actual or forecasted weather data. Weather data include daily rainfall and minimum and maximum air temperatures. Air temperatures are converted to average daily soil temperature at 5-cm soil depth using a series of equations that are specific for soil type, tillage system and previous year's crop-residue type. Daily rainfall and soil temperature estimates are combined to determine soil water potential (in megapascals) at 5-cm depth. Daily estimated soil water potential or soil temperatures are matched to empirically-derived threshold values that induce secondary dormancy in seeds of certain species. Soil growing degree days (GDD), calculated from soil temperatures, are used to project maximum emergence rates of weed seedlings. Emergence ceases on days when soil water potential falls below threshold values specific to each species. GDD based on air temperatures are used to estimate post-emergence seedling height growth. All three types of simulation provide information that allows users to answer important weed management questions in real-time. These types of questions include but are not limited to the following: (1) Are soil-applied treatments necessary? (2) How late can pre-emergence herbicides be applied? (3) When should mechanical control be implemented? (4) When should field-scouting commence and end? (5) When should post-emergence herbicides be applied?
Understanding the mechanisms and kinetics of seed aging
Authors: Walters Christina 
Published: September 2008

AbstractWhen seeds deteriorate, they lose vigour and become more sensitive to stresses upon germination. Eventually seeds lose the ability to germinate. The factors which determine the rate of this ‘aging’ are the temperature and moisture content at which seeds are stored and an ill-defined parameter, seed quality. While it has been known for many years that manipulation of these factors influences the longevity of seeds, the precise interactions among them are so poorly understood as to preclude the prediction of longevity for a particular seed lot. Concepts from studies of materials and food stability can be applied to seed aging research, and this may help us take a more integrative approach to understanding the kinetics of seed deterioration. These concepts describe the physical environment of the seed matrix in response to changing water contents and temperature. Water activity models describe the state of water in the seed, while the glass models describe the state of the aqueous solution. Both models presume that changes of state affect the nature and kinetics of chemical reactions. Thus, the physical and chemical environment within the seed are inextricably linked.
Stress protein content of matureBrassicaseeds and their germination performance
Authors: Bettey Mary , Finch-Savage W. E. 
Published: September 2008

AbstractPlants respond to sub-optimal conditions by the synthesis of specific ‘stress’ proteins, and these are thought to play a role in stress tolerance. Some of these proteins accumulate during late seed development, arguably to protect against damage during post-maturation drying and subsequent imbibition, prior to germination. Seed vigour is also determined during this late stage of seed development. High vigour seeds are those that can withstand the desiccation required for storage and successfully germinate under sub-optimal conditions to establish healthy seedlings. If stress proteins are involved in tolerating stress conditions, then they are likely to be important determinants of seed vigour. In this work the relationship between seed vigour (measured by seed germination performance following rapid aging, or under water stress) inBrassica oleraceavar.capitataand the content of two classes of stress protein (dehydrins and a low molecular weight heat shock protein HSP17.6) at maturity was examined. Dehydrins did not show a positive relationship with seed performance. However, the protein HSP17.6 showed a positive correlation with seed performance, and a treatment that reduced the amount of this protein in the seed also caused a reduction in subsequent seed performance.
The impact of groundwater level on soil seed bank survival
Authors: Bekker R. M. , Oomes M. J. M. , Bakker J. P. 
Published: September 2008

AbstractSeed longevity of plant species is an important topic in restoration management, and little is known about the effects of environmental conditions on seed survival and longevity under natural conditions. Therefore, the effect of groundwater level on the survival of seeds in the soil seed bank of a natural grassland community was investigated. Large soil cores, mesocosms, were sampled from a grassland site and transferred to two basins under a glass roof. The mesocosms were subjected to different groundwater-level treatments (high and low, respectively 5 and 30 cm below the soil surface) for nearly three years. After that period the soil seed bank of the mesocosms was sampled. In total 15 789 seeds of 38 taxa emerged from the experiment. Significant differences between the number of viable seeds that emerged in the two treatments were found for several species. More seeds ofGlyceria fluitans, Cardamine pratensisandMyosotis palustrisgerminated in the high water-level treatment, whereas fewer seeds ofJuncusspp.,Cerastium fontanumandStellaria mediawere found in this treatment than in the low water-level treatment. The experiment showed that the anoxic conditions prevailing in the high water-level treatment were beneficial to the survival of seeds of species of wet grassland communities. Species of dry grasslands, although represented by only two species, survived better under aerobic conditions.
Effects of the metal pollutants cadmium and nickel on soybean seed development
Authors: Malan H. L. , Farrant J. M. 
Published: September 2008

AbstractThe chloride salts of Cd or Ni were added to the nutrient solution in which soybean (Glycine max) plants were grown and the response of the plants to these pollutants examined. Both metals markedly reduced plant biomass and seed production. Accumulation was mostly in the roots. Nickel was more mobile than Cd, reaching higher levels in all plant parts, especially seeds. Within the tissues of mature seeds, the highest concentrations of Ni were found in the axis and testa. The highest concentrations of Cd were in the testa and cotyledon, and the lowest in the axis. When expressed on a per seed basis, metal contents of these organs increased with developmental age. Nickel amounts were lower in the pods than the seeds for all growth stages, however there was no significant difference for Cd. Cadmium reduced mature seed mass. This effect was mostly due to decreased yields of lipids, protein and carbohydrates. Although the number of seeds per pod declined as a response to Ni, seed mass was unaffected and there was no apparent effect on storage reserves.
Endosperm cap weakening and endo-β-mannanase activity during priming of tomato (Lycopersicon esculentumcv. Moneymaker) seeds are initiated upon crossing a threshold water potential
Authors: Toorop Peter E. , van Aelst Adriaan C. , Hilhorst Henk W. M. 
Published: September 2008

AbstractThe relationship between endosperm cap weakening and endo-β-mannanase activity during priming and the time to germination after priming was studied in tomato (Lycopersicon esculentum) seeds. During priming of seeds in −0.4 MPa PEG, the mechanical restraint of the endosperm cap decreased while the endo-β-mannanase activity in the endosperm cap increased. There was no decrease in required puncture force and no increase in endo-β-mannanase activity in seeds during priming in −1.0 MPa PEG. Two classes of seeds could be distinguished during priming in −0.7 MPa PEG: one with decreased required puncture force and one without. A strong correlation was found between the lowering of the mechanical restraint and endo-β-mannanase activity. It was concluded that individual seeds have to cross a threshold water potential in order to develop enzyme activity and lower their mechanical restraint. A decrease in required puncture force and increase in endo-β-mannanase activity correlated with ice crystal-induced porosity in the endosperm cap cell walls in scanning micrographs. It was presumed that ice crystal-induced porosity reflects cell-wall hydrolysis. Germination time after priming correlated positively with required puncture force during priming, depending on the osmotic potential. Seeds in −1.0 MPa PEG improved their time to germination, without a decrease in the required puncture force. Therefore it was concluded that lowering of the endosperm restraint during priming positively affects the time to germination of primed seeds but is not a prerequisite for rapid germination.
A comparative study of seed dormancy and germination in an annual and a perennial species of Senna (Fabaceae)
Authors: Baskin Jerry M. , Nan Xiaoying , Baskin Carol C. 
Published: September 2008

AbstractSeed dormancy and germination ofSenna marilandicaandS. obtusifoliawere compared in greenhouse and laboratory studies. About 90% of theS. obtusifoliaseeds were green and had hard seed coat dormancy, whereas the other 10% were brown and nondormant. Seed-colour morphs did not occur inS. marilandica, and nearly 100% of the seeds had hard seed coat dormancy. Seeds ofS. obtusifoliawere significantly heavier than those ofS. marilandica. Mechanical scarification was very effective in overcoming dormancy in seeds of both species. However, concentrated sulfuric acid, absolute ethanol and boiling water were less effective in breaking dormancy in seeds ofS. marilandicathan in those ofS. obtusifolia. Further, incubating seeds at 30/15 to 40/25°C and dry-heat treatments at 80–100°C were ineffective in breaking dormancy inS. marilandica, but significantly increased germination percentages inS. obtusifolia. In neither species were simulated daily/seasonal temperature shifts effective in breaking dormancy. Scarified seeds of both species germinated over a wide range of temperatures in both light and darkness. Under near-natural temperature conditions, seeds ofS. marilandicagerminated in spring only, whereas those ofS. obtusifoliaemerged in late spring and throughout summer. Both species can form a long-lived seed bank. Dormancy break by high field temperatures in seeds ofS. obtusifoliaallows this species to germinate throughout the warm growing season and thus contributes to its success as a weed in arable crops.
Environment and integrated agricultural systems
Authors: Hendrickson J.R. , Liebig M.A. , Sassenrath G.F. 
Published: September 2008

AbstractModern agriculture has done an excellent job producing food, feed and fiber for the world's growing population, but there are concerns regarding its continued ability to do so, especially with the world's limited resources. To adapt to these challenges, future agricultural systems will need to be diverse, complex and integrated. Integrated agricultural systems have many of these properties, but how they are shaped by the environment and how they shape the environment is still unclear. In this paper, we used commonly available county-level data and literature review to answer two basic questions. First, are there environmental limitations to the adoption of integrated agricultural systems? Second, do integrated agricultural systems have a lower environmental impact than more specialized systems? We focused on the Great Plains to answer these questions. Because of a lack of farm-level data, we used county-level surrogate indicators. The indicators selected were percent land base in pasture and crop diversity along a precipitation gradient in North Dakota, South Dakota, Nebraska and Kansas. Evaluated over the four-state region, neither indicator had a strong relationship with precipitation. In the Dakotas, both percent pasture land and crop diversity suggested greater potential for agricultural integration at the mid-point of the precipitation gradient, but there was no clear trend for Kansas and Nebraska. Integrated agricultural systems have potential to reduce the impact of agriculture on the environment despite concerns with nutrient management. Despite advantages, current adoption of integrated agricultural systems appears to be limited. Future integrated agricultural systems need to work with environmental limitations rather than overcoming them and be capable of enhancing environmental quality.
Helicobacter pylori eradication in long‐term proton pump inhibitor users is highly cost‐effective: economic analysis of the HELPUP trial
Authors: MASON J. M. , RAGHUNATH A. S. , HUNGIN A. P. S. , JACKSON W. 
Published: September 2008

SummaryBackground  Proton pump inhibitor (PPI) use is costly and about two‐thirds of prescribing is long‐term. Although 20–50% of patients may be infected with Helicobacter pylori, eradication is not normal clinical practice.Aim  To establish if H. pylori eradication in long‐term PPI users is cost‐effective.Methods  Long‐term PPI‐using patients (n = 183) testing positive for H. pylori were randomly assigned to true or placebo eradication therapy. Patients provided 2‐year resource data, and 1‐year symptom severity scores. A within‐trial cost effectiveness analysis was conducted from a British health service perspective.Results  Significant reductions in resource use occurred comparing eradication with placebo. After 2 years, PPI prescriptions (full‐dose equivalents) fell by 3.9 (P < 0.0001); clinician (GP) consultations by 2.4 (P = 0.0001); upper gastrointestinal (GI) endoscopies by 14.8% (P = 0.008); clinician GI‐related home visits by 19.9% (P = 0.005) and abdominal ultrasound scans fell by 20.3% (P = 0.005). Average net savings/patient were £93 (95% CI: 33–153) after costs of detection and eradication had been deducted. At 1 year, Leeds Dyspepsia Questionnaire symptoms fell by 3.1 (P = 0.005) and quality‐of‐life measures improved (EuroQol‐5D: 0.089, P = 0.08; visual analogue scale: 5.6, P = 0.002) favouring eradication.Conclusion  Helicobacter pylori eradication in infected, long‐term PPI users is an economically dominant strategy, significantly reducing overall healthcare costs and symptom severity.
The effect of naloxone‐3‐glucuronide on colonic transit time in healthy men after acute morphine administration: a placebo‐controlled double‐blinded crossover preclinical volunteer study
Authors: NETZER P. , SENDENSKY A. , WISSMEYER M. P. , BAUMELER S. , BATISTA C. , SCHEURER U. , KRAUSE T. , REBER P. , BRENNEISEN R. 
Published: September 2008

SummaryBackground  Constipation is a significant side effect of opioid therapy. We have previously demonstrated that naloxone‐3‐glucuronide (NX3G) antagonizes the motility‐lowering‐effect of morphine in the rat colon.Aim  To find out whether oral NX3G is able to reduce the morphine‐induced delay in colonic transit time (CTT) without being absorbed and influencing the analgesic effect.Methods  Fifteen male volunteers were included. Pharmacokinetics: after oral administration of 0.16 mg/kg NX3G, blood samples were collected over a 6‐h period. Pharmacodynamics: NX3G or placebo was then given at the start time and every 4 h thereafter. Morphine (0.05 mg/kg) or placebo was injected s.c. 2 h after starting and thereafter every 6 h for 24 h. CTT was measured over a 48‐h period by scintigraphy. Pressure pain threshold tests were performed.Results  Neither NX3G nor naloxone was detected in the venous blood. The slowest transit time was observed during the morphine phase, which was significantly different from morphine with NX3G and placebo. The pain perception was not significantly influenced by NX3G.Conclusions  Orally administered NX3G is able to reverse the morphine‐induced delay of CTT in humans without being detected in peripheral blood samples. Therefore, NX3G may improve symptoms of constipation in‐patients using opioid medication without affecting opioid‐analgesic effects.
Patient safety incidents associated with equipment in critical care: a review of reports to the UK National Patient Safety Agency
Authors: Thomas A. N. , Galvin I. 
Published: September 2008

SummaryWe reviewed all patient safety incidents reported to the UK National Patient Safety Agency between August 2006 and February 2007 from intensive care or high dependency units. Incidents involving equipment were then categorised. A total of 12 084 incidents were submitted from 151 organisations (median (range) 40 (1–634) per organisation). Of these, 1021 incidents were associated with use of equipment, most commonly involving syringe pumps/infusion devices (185 incidents), ventilators (164 incidents), haemofilters (107 incidents) and monitoring equipment (70 incidents). Twenty‐nine incidents were associated with more than temporary harm to patients. Failure or faulty equipment was described in 537 incidents (26% with some harm) and incorrect setting or use was described in 358 incidents; these were more likely to be associated with harm (39%; p = 0.001). We suggest changes to improve the reporting of incidents and to improve equipment safety.
Effects of light history on primary productivity in a phytoplankton community dominated by the toxic cyanobacterium Cylindrospermopsis raciborskii
Authors: O’BRIEN K. R. , BURFORD M. A. , BROOKES J. D. 
Published: September 2008

Summary1. The effects of instantaneous irradiance and short‐term light history on primary production were determined for samples from a subtropical water reservoir dominated by the toxic cyanobacterium Cylindrospermopsis raciborskii. 14C‐bicarbonate uptake incubations were conducted on water samples from the reservoir, for irradiance (photosynthetically active radiation) ranging from 0 to 1654 μmol quanta m−2 s−1. Prior to the 14C incubations, cells were pre‐treated at irradiance levels ranging from 0 to 1006 μmol quanta m−2 s−1.2. The average irradiance experienced by cells during the 2–2.5 h pre‐treatment incubations affected the productivity–irradiance (P–I) parameters: exposure to high light in pre‐treatment conditions caused a substantial decrease in maximum rate of primary production Pmax and the photoinhibition parameter β when compared to cells pre‐treated in the dark.3. While the data collected in this study were not sufficient to develop a full dynamic model of C. raciborskii productivity, Pmax and β were modelled as a function of pre‐treatment irradiance, and these models were applied to predict the rate of primary production as a function of both instantaneous and historical irradiance. The results indicated that while cells with a history of exposure to high irradiance will be the most productive in high irradiance, production rates will be highest overall for dark‐acclimated cells in moderate irradiance.4. Our results may explain why optically‐deep mixing favours C. raciborskii. If the mixing depth zm exceeds the euphotic depth zeu, cells will be dark‐acclimated, which will increase their rate of production when they are circulated through the euphotic zone. These results also predict that production rates will be higher during morning hours than for the same irradiance in the afternoon, which is consistent with other phytoplankton studies.5. Since the rate of production of C. raciborskii‐dominated systems cannot be described by a single P–I curve, accurate estimates of production rates will require measurements over the daily light cycle.
Capsular glucan and intracellular glycogen of Mycobacterium tuberculosis: biosynthesis and impact on the persistence in mice
Authors: Sambou Tounkang , Dinadayala Premkumar , Stadthagen Gustavo , Barilone Nathalie , Bordat Yann , Constant Patricia , Levillain Florence , Neyrolles Olivier , Gicquel Brigitte , Lemassu Anne , Daffé Mamadou , Jackson Mary 
Published: September 2008

Summary Mycobacterium tuberculosis and other pathogenic mycobacterial species produce large amounts of a glycogen‐like α‐glucan that represents the major polysaccharide of their outermost capsular layer. To determine the role of the surface‐exposed glucan in the physiology and virulence of these bacteria, orthologues of the glg genes involved in the biosynthesis of glycogen in Escherichia coli were identified in M. tuberculosis H37Rv and inactivated by allelic replacement. Biochemical analyses of the mutants and complemented strains indicated that the synthesis of glucan and glycogen involves the α‐1,4‐glucosyltransferases Rv3032 and GlgA (Rv1212c), the ADP‐glucose pyrophosphorylase GlgC (Rv1213) and the branching enzyme GlgB (Rv1326c). Disruption of glgC reduced by half the glucan and glycogen contents of M. tuberculosis, whereas the inactivation of glgA and Rv3032 affected the production of capsular glucan and glycogen, respectively. Attempts to disrupt Rv3032 in the glgA mutant were unsuccessful, suggesting that a functional copy of at least one of the two α‐1,4‐glucosyltransferases is required for growth. Importantly, the glgA mutant was impaired in its ability to persist in mice, suggesting a role for the capsular glucan in the persistence phase of infection. Unexpectedly, GlgB was found to be an essential enzyme.
Placental invasiveness and brain–body allometry in eutherian mammals
Authors: ELLIOT M. G. , CRESPI B. J. 
Published: September 2008

AbstractBrain growth is a key trait in the evolution of mammalian life history. Brain development should be mediated by placentation, which determines patterns of resource transfer from mothers to fetal offspring. Eutherian placentation varies in the extent to which a maternal barrier separates fetal tissues from maternal blood. We demonstrate here that more invasive forms of placentation are associated with substantially steeper brain–body allometry, faster prenatal brain growth and slower prenatal body growth. On the basis of the physiological literature we suggest a simple mechanism for these differences: in species with invasive placentation, where the placenta is bathed directly in maternal blood, fatty acids essential for brain development can be readily extracted by the fetus, but in species with less invasive placentation they must be synthesized by the fetus. Hence, with regard to brain–body allometry and prenatal growth patterns, eutherian mammals are structured into distinct groups differing in placental invasiveness.
Characteristics of pediatric‐onset spinal cord injury
Authors: Lee Jung H. , Sung In Y. , Kang Jin Y. , Park Song R. 
Published: September 2008

AbstractBackground:  Although children rarely experience spinal cord injuries (SCI), those who do are subject to various lifelong disabilities and morbidities. The aim of the present study was to retrospectively assess the characteristics of pediatric onset SCI patients and their differences among age groups.Methods:  Clinical characteristics were compared in 48 patients who experienced SCI during childhood and adolescence and who underwent rehabilitation treatment. Clinical characteristics were compared in patients under 4 years old (group A), 4–12 years old (group B), and 13–18 years old (group C) at SCI onset. Radiological findings were compared in 20 patients who were examined on both plain radiograph and computed tomography.Results:  The overall male : female ratio was 3:2, with SCI due to non‐traumatic causes more frequent overall. Of traumatic causes of SCI, vehicle accident was the most frequent. Of non‐traumatic causes, congenital anomaly was most frequent in group A, but tumors became dominant as age increased. Overall, thoracic cord level of injury was most frequent. SCI without radiologic abnormalities (SCIWORA) was predominant in group A, but none was observed in group C. Spinal fractures with or without subluxation accounted for >60% of group C SCI.Conclusions:  Non‐traumatic, thoracic cord injury was frequent in the pediatric SCI population. SCIWORA was predominant in younger children.