Cell death induced by ozone stress in the leaves of Populus deltoides × maximowiczii

When exposed to an acute ozone stress, cell death occurred in leaves of the O₃ sensitive Populus deltoides × maximowiczii clone Eridano. After treatment (5 h fumigation and 24 h recovery), the damaged areas covered more than 50 % of the leaf surface. At cellular level, these lesions were preceded by some apoptotic hallmarks and by biochemical and physiological alterations evoked by the apoplastic O₃ dissociation. The cell death pattern was highly localized and involved an increase of membrane permeability, externalization of phosphatidylserine, DNA fragmentation, callose accumulation, polyphenol production, and a biphasic oxidative burst accompanied by NO overproduction. These results indicate a process of programmed cell death that could have the biological significance of limiting the spreading the oxidative burst triggered by ozone dissociation in apoplastic environment. Moreover, materials derived from cell dismantling could be remobilized toward developing structures which can conclude their ontogenetic program after the stress.     

Carved trees in grazed forests in boreal Sweden—analysis of remaining trees, interpretation of past land-use and implications for conservation

Culturally modified trees (CMTs) provide unique insights into traditional knowledge and uses of the forest ecosystems. In close relation to pre-industrial livestock herding in central Sweden, it was a custom to carve text and symbols on trees and use them as notice boards in the forest. The main aim of this study was to document and analyse remaining carved trees in a managed forest landscape of 160 km². The same area was surveyed twice, once in 1986 and once in 2003. 488 carved trees were documented and classified into legible themes that were interpreted in the light of past herding practices. Name was the most common theme, found in 85% of the carvings. Most of the carvings were made in the period from the 1750s until the early 1900s. The custom of carving on trees was closely related to important grazing areas and the need to establish rights to them. The main losses of carved trees nowadays are due to their natural death and decay as most of the carved trees are located in areas that are not targeted for management. A primary recommendation for preservation is therefore to continue documentation of the trees because of the noticeable deterioration in readability of the carvings.     

Simulation of a balloon expandable stent in a realistic coronary artery—Determination of the optimum modelling strategy

Computational models of stent deployment in arteries have been widely used to shed light on various aspects of stent design and optimisation. In this context, modelling of balloon expandable stents has proved challenging due to the complex mechanics of balloon–stent interaction and the difficulties involved in creating folded balloon geometries. In this study, a method to create a folded balloon model is presented and utilised to numerically model the accurate deployment of a stent in a realistic geometry of an atherosclerotic human coronary artery. Stent deployment is, however, commonly modelled by applying an increasing pressure to the stent, thereby neglecting the balloon. This method is compared to the realistic balloon expansion simulation to fully elucidate the limitations of this procedure. The results illustrate that inclusion of a realistic balloon model is essential for accurate modelling of stent deformation and stent stresses. An alternative balloon simulation procedure is presented however, which overcomes many of the limitations of the applied pressure approach by using elements which restrain the stent as the desired diameter is achieved. This study shows that direct application of pressure to the stent inner surface may be used as an optimal modelling strategy to estimate the stresses in the vessel wall using these restraining elements and hence offer a very efficient alternative approach to numerically modelling stent deployment within complex arterial geometries. The method is limited however, in that it can only predict final stresses in the stented vessel and not those occurring during stent expansion, in which case the balloon expansion model is required.     

To what extent do current and projected increases in surface ozone affect photosynthesis and stomatal conductance of trees? A meta‐analytic review of the last 3 decades of experiments

The surface concentration of ozone ([O(3)]) has risen from less than 10 ppb prior to the industrial revolution to a day-time mean concentration of approximately 40 ppb over much of the northern temperate zone. If current global emission trends continue, surface [O(3)] is projected to rise a further 50% over this century, with larger increases in many locations including Northern Hemisphere forests. This review uses statistical meta-analysis to determine mean effects, and their confidence limits, of both the current and projected elevations of [O(3)] on light-saturated photosynthetic CO(2) uptake (A(sat)) and stomatal conductance (g(s)) in trees. In total, 348 measurements of A(sat) from 61 studies and 266 measures of g(s) from 55 studies were reviewed. Results suggested that the elevation of [O(3)] that has occurred since the industrial revolution is depressing A(sat) and g(s) by 11% (CI 9-13%) and 13% (CI 11-15%), respectively, where CI is the 95% confidence interval. In contrast to angiosperms, gymnosperms were not significantly affected. Both drought and elevated [CO(2)] significantly decreased the effect of ambient [O(3)]. Younger trees (<4 years) were affected less than older trees. Elevation of [O(3)] above current levels caused progressively larger losses of A(sat) and g(s), including gymnosperms. Results are consistent with the expectation that damage to photosynthesis depends on the cumulative uptake of ozone (O(3)) into the leaf. Thus, factors that lower g(s) lessen damage. Where both g(s) and [O(3)] were recorded, an overall decline in A(sat) of 0.21% per mmol m(-2) of estimated cumulative O(3) uptake was calculated. These findings suggest that rising [O(3)], an often overlooked aspect of global atmospheric change, is progressively depressing the ability of temperate and boreal forests to assimilate carbon and transfer water vapour to the atmosphere, with significant potential effects on terrestrial carbon sinks and regional hydrologies.     

Meiotic pairing in wheat-rye derivatives detected by genomic in situ hybridization and C-banding — A comparative analysis

Meiosis of triticalextetraploid rye hybrids (genome constitution ABRRR) was analysed by genomic in situ hybridization (GISH) and C-banding. The results obtained reveal a considerable difference between these techniques with regard to their efficiency in detecting any type of pairing, either homologous or homoeologous. Thus the percentage of pollen mother cells containing wheat/rye homoeologous associations determined by C-banding and GISH was 2.5 and 9.2, respectively. Such a discrepancy can be ascribed to a certain proportion of wheat/rye associations not being identified by C-banding. The potential and limitations of the two techniques for meiotic analysis are discussed.     

Grid — A space density analysis for recognition of noda in vegetation samples

Summary Recognition of noda is performed in a point cloud of n-space using grid analysis. The input data represent coordinates, preferably component scores, to reduce dimensionality. The exact position of the noda is approximated in an iterative search procedure which allows the user-defined space segments to drift into regions of high point density. The results are independent of group size and shape and they tend to compensate for uneven sampling in the different types of the survey site. The method gives flexibility in group recognition at different resolutions and provides a practical means to handling large data sets, while at the same time producing an optimal solution. The method, suitable to be used in the place of divisive clustering algorithms, has been applied to vegetation data with success. Results from two such applications are presented.The author expresses his thanks to Dr. L. Orlóci for discussions and critical review, and to the University of Western Ontario for computer time.     

Low use of surveillance and early diagnosis of hepatocellular carcinoma in Norway—A population-based cohort study

Background and aimsCurative treatment of hepatocellular carcinoma (HCC) is dependent on early diagnosis. Surveillance of patients at high risk for HCC is a key determinant to achieve this goal, but may be an underutilized tool. The aim of this study was to determine the rate of pre-diagnosis surveillance in patients with HCC in a large population-based cohort and to assess to what extent cirrhosis was known prior to the diagnosis of HCC.MethodsAll patients diagnosed with HCC during 2000–2009 in The South-Eastern Regional Health Authority, representing 56% of the Norwegian population, were identified from The National Cancer Registry and the medical records were reviewed.ResultsFifteen out of 486 patients (3%) were diagnosed by surveillance. Potential curative treatment was offered to 58% of the patients who underwent surveillance as opposed to 15% in the non-surveillance group. Only age ≤65 years was an independent predictor of screening in a multivariate model. Almost two thirds of the patients with cirrhosis were unrecognized prior to the HCC diagnosis. Two hundred and fourteen patients (44%) were non-cirrhotics.ConclusionRegular HCC surveillance in at-risk populations is virtually not applied in Norway and this may contribute to inferior overall survival. Failure to recognize cirrhosis and a high rate of HCC in non-cirrhotic patients will be limiting factors for the overall effectiveness of a potential surveillance program.     

Genetic analysis of tolerance to photo-oxidative stress induced by high light in winter wheat （Triticum aestivum L.）

High light induced photooxidation (HLIP) usually leads to leaf premature senescence and causes great yield loss in winter wheat. In order to explore the genetic control of wheat tolerance to HLIP stress, a quantitative trait loci (QTL) analysis was conducted on a set of doubled haploid population, derived from two winter wheat cultivars. Actual values of chlorophyll content (Chl), minimum fluorescence level (Fo), maximum fluorescence level (Fm), and the maximum quantum efficiency of photosystem Ⅱ (Fv/Fm) under both HLIP and non-stress conditions as well as the ratios of HLIP to non-stress were evaluated. HLIP considerably reduced Chl, Fm, and Fv/Fm, but increased Fo, compared with that under non-stress condition. A total of 27, 16, and 28 QTLs were associated with the investigated traits under HLIP and non-stress and the ratios of HLIP to non-stress, respectively. Most of the QTLs for the ratios of HLIP to non-stress collocated or nearly linked with those detected under HLIP condition. HLIP-induced QTLs were mapped on 15 chromosomes, involving in 1A, 1B, 1D,2A, 2B, 2D, 3A, 3B, 4A, 4D, 5B, 6A, 6B, 7A, and 7D while those expressed under non-stress condition involved in nine chromosomes, including 1B, 1D, 2A, 2B, 3B, 4A, 5A, 5B, and 7A. The expression patterns of QTLs under HLIP condition were different from that under non-stress condition except for six loci on five chromosomes. The phenotypic variance explained by individual QTL ranged from 5.0% to 19.7% under HLIP, 8.3% to 20.8% under non-stress, and 4.9% to 20.2% for the ratios of HLIP to non-stress, respectively. Some markers, for example,Xgwm192 and WMC331 on 4D regulating Chl, Fo, Fm, and Fv/Fm under HLIP condition, might be used in marker assistant selection.     

Land use planning in Ireland—a life cycle energy analysis of recent residential development in the Greater Dublin Area

Background, aim, and scope  One third of the total housing stock in the Republic of Ireland has been built in 10 years up to and including 2006 and of this approximately 34% was built in the Greater Dublin Area (GDA). Much of the housing was low-density with poor public transport links leading to doubts over its sustainability—particularly in terms of energy use. Although the country is committed to reducing greenhouse gas emissions to 13% above 1990 levels by the period 2008–2012, by 2005, emissions were already 25.4% higher than the baseline and current projections are that this figure will rise to 37% over the period. The residential sector is estimated to contribute to approximately 24.5% of energy-related CO₂ emissions. This paper estimates total emissions from residential developments in the GDA constructed between 1997 and 2006. Materials and methods  Carbon dioxide equivalent (CO₂) emissions are estimated using a life cycle assessment approach over a 100-year building lifespan and employing process, input–output and hybrid energy techniques. Life cycle stages include: construction, operation, transport, maintenance and demolition. The main data sources include: national population and industry census data, household travel survey data, residential energy performance surveys and national accounts. The GDA was split into four zones each encompassing development at increasing radii from Dublin’s city centre, namely: city centre, suburbs, exurbs and commuter towns. Results  Per capita CO₂ life cycle emissions in the GDA were found to be approximately 50–55% greater in the exurbs and commuter towns than in the city centre. Of the five life cycle stages studied, operational energy requirements (predominantly space heating and hot water, but including power) contributed most significantly to emissions (68%), followed by transport (17%), construction (9%) and maintenance/renovation (6%). Discussion  Operating emissions from dwellings in the commuter town and extra-urban zones were almost twice those in the city centre both due to larger dwelling sizes and the predominance of detached and semi-detached dwellings (with large amounts of exposed walls) in the former and the prevalence of smaller apartments in the latter. Car use was most pronounced in the zones furthest from the city centre where per capita emissions were almost twice those of residents in the city centre. Despite their smaller size, the per capita construction CO₂ emissions of apartments were approximately one third greater than for low-rise dwellings due to the greater energy intensity of the structure. However, this difference was more than compensated for by the significantly lower operational emissions referred to above. Conclusions  In 2006, recurrent CO₂ emissions (operational, transport and maintenance) from dwellings built in the GDA over the ten preceding years were 2,108 kt while construction-related emissions in that year were 1,325 kt giving a total contribution from the residential sector of 3,434 kt CO₂/annum—representing 4.9% of national emissions for that year. Had the development policy prescribed ‘city centre’-type development and transport modes, then emissions for the year 2006 would have been 2,892 kt CO₂—a reduction of almost 16% over the actual figure. However, in this scenario recurrent emissions would have been reduced to 1,417 kt CO₂—a reduction of 33% over actual levels. Recommendations and perspectives  This study supports Irish and international governments’ policies aimed at curbing CO₂ emissions from the domestic sector which focus primarily on reducing operational emissions from new and existing housing through design and construction improvements. However, it demonstrates that significant reductions in operational emissions are associated with high-density residential development with modest floor areas. Furthermore, it highlights the scope for transport emissions’ reductions through better spatial planning leading to reduced car travel.     

Uncertainty and sensitivity analysis of West Java Water Sustainability Index – A case study on Citarum catchment in Indonesia

Water sustainability indices have been recently used to measure the sustainability of water resources within a catchment. Developing a sustainability index involves various steps, some of which have uncertainties associated with them. For the recently developed West Java Water Sustainability Index (WJWSI), three sources of uncertainties were identified, namely uncertainties in the thresholds of non-categorical indicators and sub-indicators, in the weighting schemes, and in the aggregation methods. This paper presents the uncertainty and sensitivity analysis of WJWSI, based on the application of WJWSI to Citarum catchment in West Java, Indonesia. The results of the uncertainty analysis, measured by the coefficient of variation of the thresholds and the sub-indices, indicates that minimum thresholds of Land Use Changes, Coverage, Education, Poverty, Health Impact and Sanitation, and the maximum threshold of Water Quality have higher variation when compared to variation of the other thresholds. The results of the sensitivity analysis, measured by the correlation coefficients between the final index and the thresholds, indicate that changes in the thresholds of WJWSI indicators have not significantly affected the sub-index values of most indicators and sub-indicators. The sensitivity analysis also concluded that either the equal or non-equal weighting scheme can be used for future use of the aggregation of WJWSI indicators and sub-indicators, as changes from equal to non-equal weighting scheme did not significantly affect the final index. However, it was found that the final index values were most sensitive to the aggregation method used (i.e. arithmetic and geometric methods), shown by the significant changes in the final index value when the aggregation method was changed from arithmetic to geometric. The uncertainty and sensitivity analysis presented in this study will not just assist in the efficient use of the WJWSI, but will also help undertake similar analysis for other indices.     

Human Health Risk Assessment of Naturally Occurring Radioactive Materials in Produced Water—A Case Study

Human health effects from naturally occurring radioactive materials (NORM) in produced water are of concern due to their bioavailability and bioaccumulation characteristics in finfish and shellfish species used for human consumption. Being chemically similar to calcium, radium concentrates mostly in bones, shells, and exoskeletons. Previous studies have been based on the whole-body bioaccumulation of radium in fish where the distribution of radium in bone/exoskeleton and the edible parts of fish were not considered separately and thus the predicted risks were relatively high. In this article, the distribution of radium in the non-edible and edible parts of fish and the probability of exposure to a produced water plume have been studied in order to characterize human health risks. A probabilistic hydrodynamic model has been incorporated in this study. Using the concentration distribution approach, the mean cancer risks to humans were predicted in the range of 8.6 × 10^?7 to 9.5 × 10^?7, which were 2.6 to 2.7 times less than the risks predicted by using the whole body concentrations. The exceedence probability of maximum permissible human health cancer risk of 1 × 10^?4 is close to zero. At a risk level of 1 × 10^?6, the exceedence probability is 21% whereas in the whole body concentration approach it is between 45 to 49%. In this study, no effect on fish from exposure to NORM components in produced water was found.     

Generation mutant mice with large chromosomal deletion by use of irradiated ES cells—analysis of large deletion around hprt locus of ES cell

A method of generating mice from embryonic stem (ES) cells with a large chromosomal deletion produced by X-ray irradiation has been developed. Fifty-two mutant ES clones were made that carried a nested set of chromosomal deletions up to approximately 10 cM in length around the hprt locus on the X Chromosome (Chr). Germline chimeras were generated from three ES clones with deletions ranging from 200 to 700 kb. In germline male mice from two independent clones, deletions around the hprt locus yielded a runty phenotype or caused death at birth. The runty mice had approximately ⅓ the body weight and size of wild littermates and did not survive more than 3 weeks after birth. The most plausible cause of these phenotypes is defects in regions flanking the hprt locus. This method of creating mutant mice with a large chromosomal deletion is very useful for the identification and understanding of gene functions. Received: 31 October 1996 / Accepted: 16 December 1997     

High efficiency versus maximal performance — The cause of oxidative stress in eukaryotes: A hypothesis

Degenerative diseases are in part based on elevated production of ROS (reactive oxygen species) in mitochondria, mainly during stress and excessive work under stress (strenuous exercise). The production of ROS increases with increasing mitochondrial membrane potential (ΔΨ_m). A mechanism is described which is suggested to keep ΔΨ_m at low values under normal conditions thus preventing ROS formation, but is switched off under stress and excessive work to maximize the rate of ATP synthesis, accompanied by decreased efficiency. Low ΔΨ_m and low ROS production are suggested to occur by inhibition of respiration at high [ATP]/[ADP] ratios. The nucleotides interact with phosphorylated cytochrome c oxidase (COX), representing the step with the highest flux-control coefficient of mitochondrial respiration. At stress and excessive work neural signals are suggested to dephosphorylate the enzyme and abolish the control of COX activity (respiration) by the [ATP]/[ADP] ratio with consequent increase of ΔΨ_m and ROS production. The control of COX by the [ATP]/[ADP] ratio, in addition, is proposed to increase the efficiency of ATP production via a third proton pumping pathway, identified in eukaryotic but not in prokaryotic COX. We conclude that ‘oxidative stress’ occurs when the control of COX activity by the [ATP]/[ADP] ratio is switched off via neural signals.     

METAPOP—A software for the management and analysis of subdivided populations in conservation programs

We introduce a computer program for the dynamic and flexible management of conserved subdivided populations. Using molecular marker data or pedigree information, the software determines the optimal contributions (i.e., number of offspring) of each individual, the number of migrants, and the particular subpopulations involved in the exchange of individuals in order to maintain the largest level of gene diversity in the whole population with a desired control in the rate of inbreeding. Restrictions can be introduced for the total number of migrants, and the mating of particular pairs and their contribution. A full genetic diversity analysis of the population is carried out. The optimal contribution from each subpopulation to a pool of maximal gene diversity is also provided by the program.     

Characterization of genome variation in tissue cultures by RAPD fingerprinting — A methodological comment

ABSTRACT

Genome variation in tissue culture is of importance for commercial use in plant propagation as well as for basic research on plant growth and development. RAPD fingerprinting can be used to trace genetic or epigenetic changes at the genome level. In the present paper, results of RAPD analyses on primary tissue cultures are given with particular attention to the repeatability of the method. The significance of primer binding site competition for the discovery of qualitative and quantitative DNA polymorphism is discussed.     

Nitrogen uptake by crops,soil distribution and recovery of urea-N in a sorghum—wheat rotation in different soils under Mediterranean conditions

The N uptake by crops, soil distribution and recovery of 15N labelled urea-N (100 kg N ha-1) were investigated in a sorghum-wheat rotation in two silty clay soils (Foggia and Rieti Casabianca) and one silt loam soil (Rieti Piedifiume) under different mediterranean conditions. Non-exchangeable labelled NH4-N represented an important pool at both Rieti sites with higher values (p<0.05) under sorghum (14.0 and 24.6% of the urea N in the 0-20 cm layer at the end of the cropping season) than wheat whereas it was much less important in the Foggia soil (10.0% in the surface soil under sorghum). This is probably related to the clay minerals composition of the three soils; because vermiculite was present in both Rieti sites but not in the Foggia soil. At harvest from 4.4 to 5.3% of the urea N initially applied was present as microbial biomass N in the surface soil layer with no generally significant differences due to location and type of crops. Both sorghum and wheat N yields were higher in the driest site (Foggia) probably due to better light conditions, higher temperatures and irrigation during summer of the sorghum cropping period. The recovery of plant fertilizer N (about 21% for sorghum and 27% for wheat) and the percentage of N in the plant derived from the fertilizer (NDFF) were the lowest at Rieti-Casabianca probably as the result of the protection of immobilized fertilizer N against microbial mineralization by the swelling clays. The fertilizer N unaccounted for was nil or very low (10.8% at Rieti-Casabianca under wheat and 11.8 and 4.9% at Rieti-Piedifiume under sorghum and wheat, respectively). Urea-N losses occurred when Rieti Piedifiume and Rieti Casabianca soils were kept bare. In this case the urea N unaccounted for ranged from 12 to 56% of the urea N with higher losses in Rieti-Piedifiume than in Rieti-Casabianca. The higher recoveries in the latter soil were probably confirmed by the stabilizing effect of clays on the immobilized urea N. This revised version was published online in July 2006 with corrections to the Cover Date.     

Quantitative analysis of methylguanidine and guanidine in physiologic fluids by high-performance liquid chromatography—fluorescence detection method

A rapid and sensitive high-performance liquid chromatographic method has been developed for the quantitative analysis of methylguanidine and guanidine in physiological fluids. These guanidino compounds are separated on a 6 × 0.23 cm cation-exchange column with 0.5 M sodium hydroxide solution. The guanidino compounds are detected with a fluorometer, which monitors the fluorescent guanidine derivatives produced by the reaction of the eluted constituents with 9,10-phenanthrenequinone. Sensitivity to sub-nanomole levels of methylguanidine and guanidine is demonstrated. The method was successfully applied to physiological fluids such as serum and cerebrospinal fluid from uremic patients.