Determination of cisplatin and cis-diammineaquachloroplatinum(II) ion by liquid chromatography using post-column derivatization with diethyldithiocarbamate

A post-column derivatization method has been developed for the determination of cisplatin and its monohydrated form. Cisplatin was isolated on a strong anion-exchange column, while a strong cation-exchange column was used for the monohydrated complex. Diethyldithiocarbamate was used as reagent and the influence of temperature, pH and methanol content on the yield of derivative was investigated. The reaction was quantitative using a packed-bed reactor with a surrounding temperature of 115°C and a mobile phase consisting of 0.125 M succinic acid—sodium hydroxide buffer pH 5.2 and methanol (2:3, v/v). The resulting complex, Pt(DDTC)₂, was monitored photometrically at 344 nm. The precision of the determination was 11.5% (C.V.) at an injected amount of 20 ng (n = 12) for monoaqua and 8.0% (C.V.) at 9 ng (n = 10) for cisplatin. The method was used to evaluate the plasma concentration of cisplatin and its monohydrated form in a patient.     

A molecular,isozyme and morphological map of the barley (Hordeum vulgare) genome

A map of the barley genome consisting of 295 loci was constructed. These loci include 152 cDNA restriction fragment length polymorphism (RFLP), 114 genomic DNA RFLP, 14 random amplified polymorphic DNA (RAPD), five isozyme, two morphological, one disease resistance and seven specific amplicon polymorphism (SAP) markers. The RFLP-identified loci include 63 that were detected using cloned known function genes as probes. The map covers 1,250 centiMorgans (cM) with a 4.2 cM average distance between markers. The genetic lengths of the chromosomes range from 124 to 223 cM and are in approximate agreement with their physical lengths. The centromeres were localized to within a few markers on all of the barley chromosomes except chromosome 5. Telomeric regions were mapped for the short (plus) arms of chromosomes 1, 2 and 3 and the long (minus) arm of chromosomes 7.This research was also supported by other members of the NABGMP: K. Kasha, Department of Crop Science, University of Guelph, Guelph, Ontario, Canada NIG 2W1; W. Kim, Agriculture Canada Research Station, 195 Dafoe Road, Winnipeg, Manitoba, Canada R3T 2M9; A. Laroche, Agriculture Canada Research Station, P.O. Box 3000 Main, Lethbridge, Alberta, Canada,TU 4B1; S. Molnar, Plant Research Centre Agriculture Canada, Central Experimental farm, Ottawa, Ontario, Canada K1A 0C6; G. Scoles, Department of Crop Science, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N OWOThis research is part of the North American Barley Genome Mapping Project, R. A. Nilan and K. Kasha, Coordinator and Associate Coordinator, respectively Permanent address: Department of Plant Genetics, NI Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow     

The detection and attribution of extreme reductions in vegetation growth across the global land surface

Negative extreme anomalies in vegetation growth (NEGs) usually indicate severely impaired ecosystem services. These NEGs can result from diverse natural and anthropogenic causes, especially climate extremes (CEs). However, the relationship between NEGs and many types of CEs remains largely unknown at regional and global scales. Here, with satellite-derived vegetation index data and supporting tree-ring chronologies, we identify periods of NEGs from 1981 to 2015 across the global land surface. We find 70% of these NEGs are attributable to five types of CEs and their combinations, with compound CEs generally more detrimental than individual ones. More importantly, we find that dominant CEs for NEGs vary by biome and region. Specifically, cold and/or wet extremes dominate NEGs in temperate mountains and high latitudes, whereas soil drought and related compound extremes are primarily responsible for NEGs in wet tropical, arid and semi-arid regions. Key characteristics (e.g., the frequency, intensity and duration of CEs, and the vulnerability of vegetation) that determine the dominance of CEs are also region- and biome-dependent. For example, in the wet tropics, dominant individual CEs have both higher intensity and longer duration than non-dominant ones. However, in the dry tropics and some temperate regions, a longer CE duration is more important than higher intensity. Our work provides the first global accounting of the attribution of NEGs to diverse climatic extremes. Our analysis has important implications for developing climate-specific disaster prevention and mitigation plans among different regions of the globe in a changing climate.     

Facile technique of protein precipitation by application of electric current

Summary Precipitation of proteins has been achieved following passage of direct electric current in various protein solutions. Application of as low as 3 V of electric current showed precipitation but the rate increased with increase in electric current. With 9 V there was more than 85% precipitation of protein within 15 min. Precipitation occurred at a wide range of pH and temperature. Electrophoretic analysis of precipitated proteins show that they are not denatured by application of electric current. Proteins thus precipitated can be easily recovered by centrifugation.     

A Histological Evaluation of Induced Resistance to Phytophthora infestans (Mont.) de Bary in Potato Leaves

Systemically induced resistance against Phytophthora infestans in the potato cultivar ‘Bintje’ was studied histologically at the light microscopy level on the leaf surface, in the epidermis and in the mesophyll of challenged potato leaves. Systemic disease resistance was induced by a local pre-infection with the same fungus. On the leaf surface of induced plants, the germination of cysts was enhanced. In the epidermis of induced plants, papilla deposition increased and penetration decreased, whereas in the mesophyll of induced plants the spread of hyphae was reduced. It is suggested that the reduction of disease severity in induced plants is the result of the combined action of several successive defence reactions.     

Novel Miscanthus hybrids: Modelling productivity on marginal land in Europe using dynamics of canopy development determined by light interception

New biomass crop hybrids for bioeconomic expansion require yield projections to determine their potential for strategic land use planning in the face of global challenges. Our biomass growth simulation incorporates radiation interception and conversion efficiency. Models often use leaf area to predict interception which is demanding to determine accurately, so instead we use low-cost rapid light interception measurements using a simple laboratory-made line ceptometer and relate the dynamics of canopy closure to thermal time, and to measurements of biomass. We apply the model to project the European biomass potentials of new market-ready hybrids for 2020–2030. Field measurements are easier to collect, the calibration is seasonally dynamic and reduces influence of weather variation between field sites. The model obtained is conservative, being calibrated by crops of varying establishment and varying maturity on less productive (marginal) land. This results in conservative projections of miscanthus hybrids for 2020–2030 based on 10% land use conversion of the least (productive) grassland and arable for farm diversification, which show a European potential of 80.7–89.7 Mt year⁻¹ biomass, with potential for 1.2–1.3 EJ year⁻¹ energy and 36.3–40.3 Mt year⁻¹ carbon capture, with seeded Miscanthus sacchariflorus × sinensis displaying highest yield potential. Simulated biomass projections must be viewed in light of the field measurements on less productive land with high soil water deficits. We are attempting to model the results from an ambitious and novel project combining new hybrids across Europe with agronomy which has not been perfected on less productive sites. Nevertheless, at the time of energy sourcing issues, seed-propagated miscanthus hybrids for the upscaled provision of bioenergy offer an alternative source of renewable energy. If European countries provide incentives for growers to invest, seeded hybrids can improve product availability and biomass yields over the current commercial miscanthus variety.     

LEAF GAS EXCHANGE IN QUERCUS MACROCARPA (FAGACEAE): RAPID STOMATAL RESPONSES TO VARIABILITY IN SUNLIGHT IN A TREE GROWTH FORM

Responses in net photosynthesis (A), stomatal conductance to water vapor (g), and leaf xylem pressure potential (ψ) were measured in the deciduous tree Quercus macrocarpa during alternating periods of sun (photosynthetic photon flux, PPF > 1,500 μmol m^-2 sec^-1) and shade (ca. 350 μmol m^-2 sec^-1 simulating cloud cover). Measurements were made on trees growing at the gallery forest-prairie edge on the Konza Prairie Research Natural Area in northeast Kansas. The region is near the westernmost extension of the range of Q. macrocarpa where this species experiences significant seasonal water stress (minimum ψ < -2.9 MPa). Quercus macrocarpa was chosen for study because it has relatively high A (15 μmol m^-2 sec^-1) and g (300 mmol m^-2 sec^-1) in contrast to the deciduous and evergreen subalpine trees previously studied. Both trees and large saplings of Q. macrocarpa responded to alternating several minute periods of sun and shade with relatively rapid changes in A and g. Reductions in g (110 mmol m^-2 sec^-1) during shade periods lowered transpirational water losses (E) by 13% (and reduced A by 5%) relative to estimates of A and E made assuming g remained constant. Partial stomatal closure during shade was correlated with moderate enhancement in ψ (0.31 MPa) in Q. macrocarpa. However, greater increases in ψ were measured in adjacent prairie grasses exposed to similar periods of shade (0.72 MPa in Andropogon gerardii, 0.61 MPa in Sorghastrum nutans). Reduced variability in ψ in tree growth forms may reflect greater buffering of water relations associated with the large size of trees, the amount of tissue devoted to water storage, and differences in hydraulic resistance relative to herbs. Nonetheless, the gas exchange and water relations responses in Q. macrocarpa were much more similar to those previously measured in herbaceous subalpine and grassland species than to those documented for subalpine trees. Thus, rapid gas exchange responses to variable PPF may also occur in tree growth forms.     

Use of nuclear morphometry characteristics to distinguish between normal and abnormal cervical glandular histologies.

This is a methodological study exploring the use of quantitative histopathology applied to the cervix to discriminate between normal and cancerous (consisting of adenocarcinoma and adenocarcinoma in situ) tissue samples. The goal is classifying tissue samples, which are populations of cells, from measurements on the cells. Our method uses one particular feature, the IODs-Index, to create a tissue level feature. The specific goal of this study is to find a threshold for the IODs-Index that is used to create the tissue level feature. The main statistical tool is Receiver Operating Characteristic (ROC) curve analysis. When applied to the data, our method achieved promising results with good estimated sensitivity and specificity for our data set. The optimal threshold for the IODs-Index was found to be 2.12.     

Responses in stomatal conductance to elevated CO2 in 12 grassland species that differ in growth form

Responses in stomatal conductance (g _st ) and leaf xylem pressure potential ( _leaf ) to elevated CO₂ (2x ambient) were compared among 12 tallgrass prairie species that differed in growth form and growth rate. Open-top chambers (OTCs, 4.5 m diameter, 4.0 m in height) were used to expose plants to ambient and elevated CO₂ concentrations from April through November in undisturbed tallgrass prairie in NE Kansas (USA). In June and August, _leaf was usually higher in all species at elevated CO₂ and was lowest in adjacent field plots (without OTCs). During June, when water availability was high, elevated CO₂ resulted in decreased g _st in 10 of the 12 species measured. Greatest decreases in g _st (ca. 50%) occurred in growth forms with the highest potential growth rates (C₃ and C₄ grasses, and C₃ ruderals). In contrast, no significant decrease in g _st was measured in the two C₃ shrubs. During a dry period in September, reductions in g _st at elevated CO₂ were measured in only two species (a C₃ ruderal and a C₄ grass) whereas increased g _st at elevated CO₂ was measured in the shrubs and a C₃ forb. These increases in g _st were attributed to enhanced _leaf in the elevated CO₂ plants resulting from increased soil water availability and/or greater root biomass. During a wet period in September, only reductions in g _st were measured in response to elevated CO₂. Thus, there was significant interspecific variability in stomatal responses to CO₂ that may be related to growth form or growth rate and plant water relations. The effect of growth in the OTCs, relative to field plants, was usually positive for g _st and was greatest (>30%) when water availability was low, but only 6–12% when _leaf was high.The results of this study confirm the importance of considering interactions between indirect effects of high CO₂ of plant water relations and direct effects of elevated CO₂ on g _st , particularly in ecosystems such as grasslands where water availability often limits productivity. A product of this interaction is that the potential exists for either positive or negative responses in g _st to be measured at elevated levels of CO₂.