• The high-throughput phenotypic analysis of Arabidopsis thaliana collections requires methodological progress and automation. Methods to impose stable and reproducible soil water deficits are ...presented and were used to analyse plant responses to water stress. • Several potential complications and methodological difficulties were identified, including the spatial and temporal variability of micrometeorological conditions within a growth chamber, the difference in soil water depletion rates between accessions and the differences in developmental stage of accessions the same time after sowing. Solutions were found. • Nine accessions were grown in four experiments in a rigorously controlled growth-chamber equipped with an automated system to control soil water content and take pictures of individual plants. One accession, An1, was unaffected by water deficit in terms of leaf number, leaf area, root growth and transpiration rate per unit leaf area. • Methods developed here will help identify quantitative trait loci and genes involved in plant tolerance to water deficit.
The spatial distributions of leaf expansion rate, cell division rate and cell size was examined under contrasting soil water conditions, evaporative demands and temperatures in a series of ...experiments carried out in either constant or naturally fluctuating conditions. They were examined in the epidermis and all leaf tissues. (1) Meristem temperature affected relative elongation rate by a constant ratio at all positions in the leaf. If expressed per unit thermal time, the distribution of relative expansion rate was independent of temperature and was similar in all experiments with low evaporative demand and no water deficit. This provides a reference distribution, characteristic of the studied genotype, to which any distribution in stressed plants can be compared. (2) Evaporative demand and soil water deficit affected independently the distribution of relative elongation rate and had near‐additive effects. For a given stress, a nearly constant difference was observed, at all positions of the leaf, between the relative elongation rates of stressed plants and those of control plants. This caused a reduction in the length of the zone with tissue elongation. (3) Methods for calculating cell division rate in the epidermis and in all leaf tissues are proposed and discussed. In control plants, the zone with cell division was 30 mm and 60 mm long in the epidermis and in whole tissues, respectively. Both this length and relative division rate were reduced by soil water deficit. The size of epidermal and of mesophyll cells was nearly unaffected in the leaf zone with both cell division and tissue expansion, suggesting that water deficit affects tissue expansion rate and cell division rate to the same extent. Conversely, cell size of epidermis and mesophyll were reduced by water deficit in mature parts of the leaf.
As it is imperative for the damage evaluation of infrastructures to establish an efficient non-destructive testing (NDT), an acoustic emission (AE) tomography technique has been developed. Authors ...has been studying tomography techniques based on elastic-wave and acoustic emission (AE) to visualize the internal defects in concrete. In the result of AE tomography, it can reasonably be assumed that lower elastic-wave velocity corresponds to heavier deterioration. Thus, the AE tomography estimates wave velocity distribution, which is supposed to be decreased as the damage progresses, inside the reinforced concrete. The AE tomography combines an iterative AE source location algorithm with travel-time tomography to produce a 3D visualization of the elastic wave velocity. However, since the computation for the elastic wave ray-trace algorithm considering all potential detours of elastic waves takes up much time, and in the case that only a few AE signals are detected, AE tomography technique does not always work efficiently. In this paper, AE signals induced by random hammering and rain droplets, which provide elastic waves with a variety of frequency, on surface of RC deck are utilized as elastic waves' excitations, and wave velocity and attenuation tomography assuming linear ray paths are performed in conjunction with AE source locations. Accordingly, random hammering lead to a hundred of AE events after in-situ measurement for a few minutes and rain-induced elastic waves also does to thousands of those as well for an hour. Consequently, the 3D tomography results show accurate and time-saving analysis, compared to the above-mentioned conventional AE tomography technique, for quantifying the damage of RC slab.
The EURODELTA-Trends multi-model chemistry-transport experiment has been designed to facilitate a better understanding of the evolution of air pollution and its drivers for the period 1990–2010 in ...Europe. The main objective of the experiment is to assess the efficiency of air pollutant emissions mitigation measures in improving regional-scale air quality. The present paper formulates the main scientific questions and policy issues being addressed by the EURODELTA-Trends modelling experiment with an emphasis on how the design and technical features of the modelling experiment answer these questions. The experiment is designed in three tiers, with increasing degrees of computational demand in order to facilitate the participation of as many modelling teams as possible. The basic experiment consists of simulations for the years 1990, 2000, and 2010. Sensitivity analysis for the same three years using various combinations of (i) anthropogenic emissions, (ii) chemical boundary conditions, and (iii) meteorology complements it. The most demanding tier consists of two complete time series from 1990 to 2010, simulated using either time-varying emissions for corresponding years or constant emissions. Eight chemistry-transport models have contributed with calculation results to at least one experiment tier, and five models have – to date – completed the full set of simulations (and 21-year trend calculations have been performed by four models). The modelling results are publicly available for further use by the scientific community. The main expected outcomes are (i) an evaluation of the models' performances for the three reference years, (ii) an evaluation of the skill of the models in capturing observed air pollution trends for the 1990–2010 time period, (iii) attribution analyses of the respective role of driving factors (e.g. emissions, boundary conditions, meteorology), (iv) a dataset based on a multi-model approach, to provide more robust model results for use in impact studies related to human health, ecosystem, and radiative forcing.
Highlights • A monoclonal antibody (LiD1mAb16) against a recombinant SMase D isoform was produced. • LiD1mAb16 was cross-reactive with protein spots from different Loxosceles species. • LiD1mAb16 ...recognizes a linear epitope in the catalytic loop of SMases D. • LiD1mAb16 showed neutralizing potential. • This mAb is a candidate for therapeutic serum development or immunodiagnostic assays.
Abstract Atroxlysin-I (Atr-I) is a hemorrhagic snake venom metalloproteinase (SVMP) from Bothrops atrox venom, the snake responsible for the majority of bites in the north region of South America. ...SVMPs like Atr-I produce toxic effects in victims including hemorrhage, inflammation, necrosis and blood coagulation deficiency. Mapping of B-cell epitopes in SVMPs might result in the identification of non-toxic molecules capable of inducing neutralizing antibodies and improving the anti-venom therapy. Here, using the SPOT-synthesis technique we identified two epitopes located in the N-ter region of Atr-I (AtrEp1—22 YNGNSDKIRRRIHQM36 ; and AtrEp2—55 GVEIWSNKDLINVQ68 ). Based on the sequence of AtrEp1 and AtrEp2 a third peptide named Atr-I biepitope (AtrBiEp) was designed and synthesized (23 NGNSDKIRRRIH34 GG55 GVEIWSNKDLINVQ68 ). AtrBiEp was used to immunize BALB/c mice. Anti-AtrBiEp serum cross-reacted against Atr-I in western blot and was able to fully neutralize the hemorrhagic activity of Atr-I. Our results provide a rational basis for the identification of neutralizing epitopes on Atr-I snake venom toxin and show that the use of synthetic peptides could improve the generation of immuno-therapeutics.
There is evidence that immune-activated macrophages infected with the Human Immunodeficiency Virus (HIV) are associated with tissue damage and serve as a long-lived viral reservoir during therapy. In ...this study, we analyzed 780 HIV genetic sequences generated from 53 tissues displaying normal and abnormal histopathology. We found up to 50% of the sequences from abnormal lymphoid and macrophage rich non-lymphoid tissues were intra-host viral recombinants. The presence of extensive recombination, especially in non-lymphoid tissues, implies that HIV-1 infected macrophages may significantly contribute to the generation of elusive viral genotypes in vivo. Because recombination has been implicated in immune evasion, the acquisition of drug-resistance mutations, and alterations of viral co-receptor usage, any attempt towards the successful eradication of HIV-1 requires therapeutic approaches targeting tissue macrophages.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We present a new global three‐dimensional chemical‐transport model (called MOZART) developed in the framework of the NCAR Community Climate Model (CCM) and aimed at studying the distribution and ...budget of tropospheric ozone and its precursors. The model, developed with a horizontal resolution of 2.8° in longitude and latitude, includes 25 levels in the vertical between the Earth's surface and an upper boundary located at approximately 35 km altitude. In its present configuration the model calculates the global distribution of 56 chemical constituents with a timestep of 20 min, and accounts for surface emission and deposition, large‐scale advective transport, subscale convective and boundary layer exchanges, chemical and photochemical transformations, as well as wet scavenging. Transport is simulated “off line” from CCM with dynamical variables provided every 3 hours from preestablished history tapes. Advection is calculated using the semi‐Lagrangian transport scheme Rasch and Williamson, 1990 developed for the MATCH model of Rasch et al. 1997. Convective and boundary layer transports are expressed according to Hack 1994 and Holtslag and Boville 1993, respectively. A detailed evaluation of the model results is provided in a companion paper Hauglustaine et al., this issue. An analysis of the spatial and temporal variability in the chemical fields predicted by the model suggests that regional events such as summertime ozone episodes in polluted areas can be simulated by MOZART.
Leaf expansion rate varies with leaf temperature, photon flux density (PPFD), evaporative demand and soil water
status. In most simulation models, it is calculated every day by multiplying the amount ...of carbohydrate available
to leaves by specific leaf area (SLA). However, leaf expansion rate is considerably reduced by mild water deficits
which do not affect photosynthesis, and is not affected by a reduction in the PPFD intercepted during rapid leaf
expansion. Specific leaf area undergoes a several-fold variability depending on PPFD, soil water status and time
of day. It is increased when environmental conditions have a greater depressive effect on expansion rate than on
photosynthesis, and is decreased in the opposite case. It is therefore appropriate to model leaf expansion
independently of the plant carbon budget. Consistent characteristics can be deduced from a series of experiments,
allowing a model of leaf expansion to be proposed. (i) Time courses of relative leaf expansion rate and of epidermal
cell division rate are well conserved within a plant and across a large range of environmental conditions, provided
that durations and rates are expressed in thermal time. Maximum relative rates are common to all zones of a leaf
and to all leaves of a plant, in maize and sunflower. (ii) A water deficit, or a reduction in intercepted PPFD,
imposed in the first half of the period of leaf development affects the relative expansion rate in the deficit only, but
permanently affects the absolute expansion rate. In contrast, a reduction in PPFD causes no effect on leaf
expansion if imposed in the rapid expansion period when the leaf is autotrophic. (iii) Expansion rate is related to
evaporative demand and to the concentration of ABA in the xylem sap with relationships that apply under both
field and laboratory conditions. (iv) Tissue expansion and epidermal cell division behave as independent processes
which determine epidermal cell area at each time.
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