Extension Growth Research Articles

Binary Bamboo Forest Growth Optimization Algorithm for Feature Selection Problem.

Inspired by the bamboo growth process, Chu et al. proposed the Bamboo Forest Growth Optimization (BFGO) algorithm. It incorporates bamboo whip extension and bamboo shoot growth into the optimization process. It can be applied very well to classical engineering problems. However, binary values can only take 0 or 1, and for some binary optimization problems, the standard BFGO is not applicable. This paper firstly proposes a binary version of BFGO, called BBFGO. By analyzing the search space of BFGO under binary conditions, the new curve V-shaped and Taper-shaped transfer function for converting continuous values into binary BFGO is proposed for the first time. A long-mutation strategy with a new mutation approach is presented to solve the algorithmic stagnation problem. Binary BFGO and the long-mutation strategy with a new mutation are tested on 23 benchmark test functions. The experimental results show that binary BFGO achieves better results in solving the optimal values and convergence speed, and the variation strategy can significantly enhance the algorithm's performance. In terms of application, 12 data sets derived from the UCI machine learning repository are selected for feature-selection implementation and compared with the transfer functions used by BGWO-a, BPSO-TVMS and BQUATRE, which demonstrates binary BFGO algorithm's potential to explore the attribute space and choose the most significant features for classification issues.

Calcification response of reef corals to seasonal upwelling in the northern Arabian Sea (Masirah Island, Oman)

Abstract. Tropical shallow-water reefs are the most diverse ecosystems in the ocean. Their persistence rests upon adequate calcification rates of the reef building biota, such as reef corals. Coral calcification is favoured in oligotrophic environments with high seawater saturation states of aragonite (Ωsw), which leads to an increased vulnerability to anthropogenic ocean acidification and eutrophication. Here we present Porites calcification records from the northern Arabian Sea upwelling zone and investigate the coral calcification response to low Ωsw and high nutrient concentrations due to seasonal upwelling. The calcification rate was determined from the product of skeletal extension rate and bulk density. Skeletal Ba/Ca and Li/Mg proxy data were used to identify skeletal portions that calcified during upwelling and non-upwelling seasons, respectively, and to reconstruct growth temperatures. With regard to sub-annual calcification patterns, our results demonstrate compromised calcification rates during the upwelling season. This is due to declining extension rates, which we attribute to light dimming caused by high primary production. Interestingly, seasonal variations in skeletal density show no relationship with temporally low Ωsw during upwelling. This suggests relatively constant, year-round saturation states of aragonite at the site of calcification (Ωcf) independent of external variability in Ωsw. Although upwelling does not affect seasonal density variability, exceptionally low mean annual density implies permanent Ωcf adjustment to the lowest sub-annual Ωsw (e.g. upwelling). In the Arabian Sea upwelling zone, the mean annual calcification rate is similar to Porites from non-upwelling regions because low skeletal density is compensated by high extension growth. Variable responses of reef coral extension to nutrients, which either exacerbate or compensate negative effects of diminished skeletal density associated with ocean acidification, may therefore be critical to the maintenance of adequate carbonate accumulation rates in coral reefs under global change.

Study of Apple Varieties in High-Density Plantation under Cold Dry Temperate Conditions of Kinnaur

The study was carried out to evaluate four apple varieties on different rootstocks under high-density plantations in the cold temperate region of Kinnaur for growth, yield and quality attributes. The experiment evaluated four apple varieties ‘Red Cap Valtod/MM 106’, ‘Red Velox/M9’, ‘Jeromine/M9’ and ‘Super Chief/MM 106’ planted at a spacing of 2.5×1.0 m2 in Randomized Block Design, with four replicates. From the evaluation of data on growth, floriculture and quality standards, it was clear that var. Jeromine/M9 followed by Red Velox/M9 has recorded better horticultural performance than other varieties studied. Among different varieties Red Velox/M9 recorded maximum shoot extension growth (22.65 cm), trunk girth (47.27 mm) and tree height (340.02 cm), tree spread (175.52 E-W and 181.68 cm N-S), number of fruit set tree-1 (41.85), fruit Breadth (78.90 mm), fruit weight (207.39 g fruit-1), TSS (10.11 °Brix), whereas, maximum fruit set (25.48%), fruit length (71.74 mm), yield (3.59 kg tree-1) and productivity (14.35 MT Hac-1) was recorded in cultivar Jeromine/M9. However, the maximum number of fruits tree-1 was observed in the variety Red Cap Vatod/MM 106. Variety, Red Velox /M9 was found to be superior for growth, flowering, yield and quality characteristics with good market potential under Kinnaur conditions.

Variability Patterns in Guava (Psidium guajava L.) Seedlings Progenie for Growth and Leaf Parameters

The present study was conducted to assess variation among existing guava trees of seedling origin. During 2018, a total of 60 healthy seedling guava of trees were marked for study. Marked trees were observed to be erect, spreading and drooping in growth habit, varying in tree height (4.0–10.9m), trunk girth (40.3–114.3 cm), extension growth of twigs (15.4–22.5 cm) and fruit yield (15.4–32.8 kg/tree). The variation was observed in shape of the leaf (round, ovate, obtrullate, obovate and oblong), colour of mature leaf (green to dark green), leaf area (34.42–55.22 cm2 ) and leaf chlorophyll index (32.30-54.80 SPAD meter).Based on overall distinguishing qualities, four of the 60 guava seedling trees tested were identified as "elite."These high-variation traits will be used in a guava breeding programme to select top types, genotypes and vegetatively replicate them on a commercial scale.

Fatigue behavior of corroded steel plates strengthened with CFRP plates

This paper presents an experimental study performed to investigate the effectiveness of carbon fiber reinforced polymer (CFRP) plates in extending fatigue life of corroded steel plates. Specimens with five kinds of corrosion damage level, four kinds of strengthening configuration and four kinds of applied fatigue stress amplitude were tested and the primary fatigue behavior indications consist of failure mode, fatigue fractography, fatigue life and crack propagation were analyzed. Results showed that externally patching CFRP plates significantly strengthened the fatigue behavior of corroded steel plates, and even made the fatigue life of corroded steel plates recovered or exceeded that of the un-corroded ones, the fatigue life of the patched specimen which presented the most significant strengthening effectiveness even showed a fatigue life extension of more than 85.3 times with respect to the un-patched corroded steel plate and approximately 2 times over the un-corroded steel plate. Results also indicated that different strengthening configurations appeared to have diversity effect on the fatigue life extension and crack growth retardation of corroded steel plates, end anchorage measures effectively delayed the failure process of CFRP bonding interface and improved the fatigue strengthening effect, increasing CFRP strengthening stiffness or adopting prestressed CFRP plates significantly reduced the crack growth rate and extended the fatigue life of corroded steel plates. The outcome of the tests provided meaningful references and essential data for the reliable application of CFRP strengthening system in the fatigue performance improvement of corroded steel structures.

Triacylglycerol biosynthesis in shaded seeds of tung tree (Vernicia fordii) is regulated in part by Homeodomain Leucine Zipper 21.

Light quantity and quality affect many aspects of plant growth and development. However, few reports have addressed the molecular connections between seed oil accumulation and light conditions, especially dense shade. Shade-avoiding plants can redirect plant resources into extension growth at the expense of leaf and root expansion in an attempt to reach areas containing richer light. Here, we report that tung tree seed oil accumulation is suppressed by dense shade during the rapid oil accumulation phase. Transcriptome analysis confirmed that oil accumulation suppression due to dense shade was attributed to reduced expression of fatty acid and triacylglycerol biosynthesis-related genes. Through weighted gene co-expression network analysis, we identified 32 core transcription factors (TFs) specifically upregulated in densely shaded seeds during the rapid oil accumulation period. Among these, VfHB21, a class I homeodomain leucine zipper TF, was shown to suppress expression of FAD2 and FADX, two key genes related to α-eleostearic acid, by directly binding to HD-ZIP I/II motifs in their respective promoter regions. VfHB21 also binds to similar motifs in the promoters of VfWRI1 and VfDGAT2, two additional key seed lipid regulatory/biosynthetic genes. Functional conservation of HB21 during plant evolution was demonstrated by the fact that AtWRI1, AtSAD1, and AtFAD2 were downregulated in VfHB21-overexpressor lines of transgenic Arabidopsis, with concomitant seed oil reduction, and the fact that AtHB21 expression also was induced by shade. This study reveals some of the regulatory mechanisms that specifically control tung tree seed oil biosynthesis and more broadly regulate plant storage carbon partitioning in response to dense shade conditions.

Antimicrobial properties of phytohormone (gibberellins) against phytopathogens and clinical pathogens.

The in vitro antimicrobial potential of physiologically active diterpenoid plant-derived gibberellins (gibberellic acids; GAs) was tested on microbial pathogens of significance to plant and human health. The racemic enantiomer GA3 produced varying inhibitory effects against a wide range of plant host disease causal agents (phytopathogens) comprising fungi, oomycetes and bacteria. The results showed that GA3 effected either strong growth arrest of phytopathogenic fungi or holistic biocidal effects on oomycete and phytopathogenic fungi at higher concentration (>10–50 mM) and increased hyphal extension growth when the concentration of GA3 was lowered (<10−0.1 mM). When human clinical pathogenic bacteria cohorts were challenged with gibberellin enantiomers, viz GA1, GA4, GA5, GA7, GA9 and GA13 (50 mM), employing Kirby–Bauer disc bioassay methods for assessment of their efficacies, no inhibitory effect was seen with gibberellin enantiomers, viz GA1, GA3, GA5 and GA13, while GA4 inhibited all human clinical bacterial organisms examined, with GA7 and GA9 showing limited activity. The antibiotic effects of enantiomeric diterpenoid phytohormones evinced in our preliminary study raise prospects for further studies to fully examine their potential therapeutic value for human healthcare and their compliance with cytotoxicity and other ethical considerations in the future.

Cryptochrome 1a of tomato modulates nutritional deficiency responses

The blue light photoreceptor cryptochromes are involved in nutritional response pathways in plants. Evidence shows that cryptochromes mediate the control of genes related to nutrients accumulation in plants. However, nothing is known about the role of cryptochrome 1a (cry1a) in tomato (Solanum lycopersicum L.) nutritional stress responses. Thus, this study aims to evaluate the importance of cry1a photoreceptors in plant responses to nutrient deficiency. To this end, we proposed the use of a tomato mutant carrying a lesion in a gene encoding the blue light photoreceptor cry1a (cry1a) and its wild type (WT; cv. Moneymaker). Both genotypes (20-day-old plants) were grown under treatments consisting of a complete nutrient solution and the individual omission of each nutrient (–N, –P, –K, –Ca, or –S) from a balanced nutrient solution. Subsequently, we measured the growth, pigmentation, oxidative stress, and nutrient accumulation, as well as uptake efficiency, transport efficiency, and use efficiency of nutrients in all treated plants. The cry1a plants had greater shoot extension growth than WT plants in all tested growth conditions, although the shoot biomass accumulation with cry1a was greater than in the WT only under Ca omission. Except in the –N and –Ca conditions, the cry1a plants accumulated less root biomass than WT plants. In addition, leaf pigments (chlorophyll a+b and carotenoids) were reduced in the mutant plants compared to WT plants grown under CS, –P, and –S conditions. Thus, considering that WT plants have the full functions of cry1a photoreceptor, here we showed that cry1a plays an important role in the nutrient deficiency responses in tomato, particularly, mediating growth and development of stressed plants through changes in plant growth and oxidative stress, as well as the nutrient contents and efficiencies of transport use.

Cretaceous growth strata in terrigenous basins in the East Yangtze Block: A response to Early Cretaceous extension in Southeast China

Cretaceous syntectonic growth strata in terrigenous basins in Southeast China have scarcely been reported in previous studies. This work focusses on the growth strata of the Early Cretaceous red beds in the East Yangtze Block (EYB), especially in the Huangshan Basin in southern Anhui Province, to help determine the Late Mesozoic tectonic domain and the precise timing of the initiation of extensional tectonics in Southeast China. Field observations show that the dip angles of the red conglomerate‐bearing sandstones from the lower part of the Huizhou Fm. vary from 49° to gentle dips towards the basin centre and that the visible and estimated thickness within a single bed increases slightly downward from the upper to the lower part. These characteristics indicate that the sedimentary area of the Early Cretaceous Huizhou Formation (Fm.) has undergone an extensional process with the expansion and deepening of the sedimentary basin by rotation of the border surface (limb) and thus deposited the extension growth strata simultaneously with (or closely after) the 139 Ma Shiling volcanic activity. Caused by a NW‐SE‐oriented extensional stress field since ca. 140 Ma, a model in which NE‐SW‐oriented tectonic lines transform to E‐W‐trending tectono‐magmatic belts by intersecting and inheriting the previous E‐W‐trending tectonic fabrics is established in the present work. Consequently, these phenomena are influenced by Palaeo‐Pacific Plate rollback and the inheritance of a structural framework from the regional basement strata and deformation series.

Photoperiodic Flowering Response of Essential Oil, Grain, and Fiber Hemp (Cannabis sativa L.) Cultivars.

Cultivation of hemp (Cannabis sativa L.) in tropical and subtropical regions can be challenging if the flowering behavior of a given cultivar is unknown, poorly understood, or not accurately selected for the photoperiod. Identifying cultivars adapted to local environmental conditions is key to optimizing hemp vegetative and flowering performance. We investigated the effects of varying light cycles in regulating extension growth and flowering response of 15 essential oil and 12 fiber/grain hemp cultivars both indoors and outdoors. Plants were subjected to 11 photoperiods in the controlled rooms ranging from 12 to 18 h, and natural day length in the field. The critical photoperiod threshold was identified for seven essential oil cultivars and two fiber/grain cultivars. “Cherry Wine-CC,” “PUMA-3,” and “PUMA-4” had the shortest critical day length between 13 h 45 min and 14 h. The flowering of essential oil cultivars was generally delayed by 1–2 days when the photoperiod exceeded 13 h compared with 12 h, and flowering was further delayed by 7–8 days when the photoperiod exceeded 14 h. In fiber/grain cultivars, flowering was generally delayed by 1–3 days when the day length exceeded 14 h. Flowering for most essential oil cultivars was delayed by 5–13 days under a 14-h photoperiod compared with 13 h 45 min, suggesting a photoperiod difference as little as 15 min can significantly influence the floral initiation of some essential oil cultivars. Cultivars represented by the same name but acquired from different sources can perform differently under the same environmental conditions, suggesting genetic variation among cultivars with the same name. Average days to flower of fiber/grain cultivars was correlated with reported cultivar origin, with faster flowering occurring among northern cultivars when compared with southern cultivars. Plant height generally increased as the day length increased in essential oil cultivars but was not affected in fiber/grain cultivars. In addition, civil twilight of ~2 μmol·m−2·s−1 was discovered to be biologically effective in regulating hemp flowering. Collectively, we conclude that most of the essential oil cultivars and some southern fiber/grain cultivars tested express suitable photoperiods for tropical and sub-tropical region cultivation.

Interdependencies between regulatory capital, credit extension and economic growth

Since the introduction of the third Basel Accord (Basel III) in 2011, there have been debatable outcomes regarding the effects of increased regulatory capital on economic growth. We aim to add clarity to some of these debates by investigating one primary channel through which regulatory capital may affect economic growth, viz. credit extension to the private sector. We capture credit extension through four dimensions, namely: bank credit to the private sector, bank credit to households, bank credit to firms, and bank credit-to-deposit ratio. The latter we use as a metric to capture funding (in)stability. We use a panel vector autoregression (pVAR) model on a sample of 124 countries, across the period 1998–2015 and analyse impulse response functions and forecast error variance decompositions to investigate the interdependence of regulatory capital, credit extension, and GDP growth. Our results indicate that regulatory capital reduces unstable credit (credit that may induce economic distress) while improving GDP growth. Simultaneously, such unstable credit shows negative effects on GDP growth. From this evidence, we infer that regulatory capital can induce funding stability within banking sectors, which can encourage sustainable economic growth. This provides strong support for the Basel III changes which have put more emphasis on Tier 1 capital and stable funding.

Colony-Level 3D Photogrammetry Reveals That Total Linear Extension and Initial Growth Do Not Scale With Complex Morphological Growth in the Branching Coral, Acropora cervicornis

The ability to quantify changes in the structural complexity of reefs and individual coral colonies that build them is vital to understanding, managing, and restoring the function of these ecosystems. However, traditional methods for quantifying coral growth in situ fail to accurately quantify the diversity of morphologies observed both among and within species that contribute to topographical complexity. Three-dimensional (3D) photogrammetry has emerged as a powerful tool for the quantification of reefscape complexity but has yet to be broadly adopted for quantifying the growth and morphology of individual coral colonies. Here we debut a high-throughput method for colony-level 3D photogrammetry and apply this technique to explore the relationship between linear extension and other growth metrics in Acropora cervicornis. We fate-tracked 156 individual coral transplants to test whether initial growth can be used to predict subsequent patterns of growth. We generated photographic series of fragments in a restoration nursery immediately before transplanting to natural reef sites and re-photographed coral at 6 months and 1 year post-transplantation. Photosets were used to build 3D models with Agisoft Metashape, which was automated to run on a high-performance computing system using a custom script to serially process models without the need for additional user input. Coral models were phenotyped in MeshLab to obtain measures of total linear extension (TLE), surface area, volume, and volume of interstitial space (i.e., the space between branches). 3D-model based measures of TLE were highly similar to by-hand measurements made in the field (r = 0.98), demonstrating that this method is compatible with established techniques without additional in water effort. However, we identified an allometric relationship between the change in TLE and the volume of interstitial space, indicating that growth in higher order traits is not necessarily a linear function of growth in branch length. Additionally, relationships among growth measures weakened when comparisons were made across time points, implying that the use of early growth to predict future performance is limited. Taken together, results show that 3D photogrammetry is an information rich method for quantifying colony-level growth and its application can help address contemporary questions in coral biology.

Digital transformation of russian economy: challenging the highest rank in the global innovation development

A simple prognostic method was applied to estimate the percentage ratio of the digital economy in Russia’s GDP relying on technology solutions expenditure and sectoral investment. The research indicates a significant impact of Russia’s digital sector on innovation development in B2B, B2G, and B2C segments. The prognostic analysis shows the extension of on-line education, social networking, e-commerce, private and corporate banking, and end-to-end technology solutions in manufacturing. The findings point at the opportunity for the sectoral investment extension and steady annual growth 7-8 % in the next few years. Due to requirements on updating the technological solutions in the related public services, the digital sphere can support the annual growth in the national economy by 1,0-1,2 % until 2024. Respectively the digital economy in Russia will be growing faster the world's average to provide the sector’s contribution of 8,0-8,1 % in GDP by 2024. The findings show the digital platforms are becoming a driver for innovation development integrating the production process, cloud resources, data analysis, and e-learning services. The research contains hints on improving the research efficiency and winning the talent battle that promises to improve the country’s global innovation and economic ranks.

Experimental Examination of Crack Extension in Steel with Notch Under Tensile Loading and Corrosive Environment

Carbon steels are the most versatile engineering material which are widely used in much industry for making automotive and machinery equipment or components and also used in structural and constructional work. Under loading condition, the effect of environment said materials is unique in every application. So it is necessary to experimentally investigate for the future life prediction of such material in term of crack extension and crack growth rate. In the present work, a study has to be made to investigate the crack extension and crack growth rate in steel under loading condition and different corrosive environments. Tensile loading has been done by using universal testing machine to find tensile properties in terms of fracture stress. Simultaneously with tensile loading measurement of change in electrical resistance across the notch has measured by instrument Digital Micro-Ohm Meter, in which the increase in electrical resistance can be directly correlated to the formation and extension of crack. Finally, change in electrical resistance measured value is converted into crack extension and crack growth rate with mathematical relation. Further crack extension of notched sample has been carried out after exposure to different environmental conditions.

Gluten Protein Compositional Changes in Response to Nitrogen Application Rate

Field trials were conducted to evaluate the effect of nitrogen level on wheat protein content and composition in 16 cultivars over two years at three locations. The nitrogen treatment comprised two nitrogen levels, 0 kg ha−1 as low and 100 kg ha−1 as high nitrogen, applied as top dressings of 50 kg nitrogen per ha at tillering and stem extension growth stages. Increased nitrogen level generally enhanced grain protein by 11.3% (11.5% vs. 12.8%). Considering protein composition determined by reversed phase–high-pressure liquid chromatography, higher nitrogen supply generally enhanced the proportion of total gliadins, α-gliadins, γ-gliadins and high-molecular-weight glutenin subunits by 1.1%, 2.0%, 3.7%, 0.6% and 0.9%, respectively, and reduced albumins and globulins, ω-gliadins, total glutenins and low-molecular-weight glutenin subunits by 1.1%, 1.7%, 1.9% and 3.2%. Under a high nitrogen level, the historical cultivars Libellula, San Pastore and U-1 had a higher protein content (13.1–15.2%) with significantly higher total gliadins, which resulted in a significantly higher gliadin/glutenin ratio (1.68–1.92). In the modern cultivars, protein content varied between 11.4% and 14.6% with a well-balanced gliadin/glutenin ratio (1.08–1.50), except for cultivar MV Nemere which had a high gliadin/glutenin ratio at both nitrogen levels (1.81 vs. 1.87). In summary, increasing nitrogen level enhanced grain protein content while the composition of gliadin and glutenin fractions was changed to a lesser extent and was largely cultivar specific and therefore should be considered for wheat baking quality assessment and breeding purposes.

Forward Modeling Reveals Multidecadal Trends in Cambial Kinetics and Phenology at Treeline

Significant alterations of cambial activity might be expected due to climate warming, leading to growing season extension and higher growth rates especially in cold-limited forests. However, assessment of climate-change-driven trends in intra-annual wood formation suffers from the lack of direct observations with a timespan exceeding a few years. We used the Vaganov-Shashkin process-based model to: (i) simulate daily resolved numbers of cambial and differentiating cells; and (ii) develop chronologies of the onset and termination of specific phases of cambial phenology during 1961–2017. We also determined the dominant climatic factor limiting cambial activity for each day. To asses intra-annual model validity, we used 8 years of direct xylogenesis monitoring from the treeline region of the Krkonoše Mts. (Czechia). The model exhibits high validity in case of spring phenological phases and a seasonal dynamics of tracheid production, but its precision declines for estimates of autumn phenological phases and growing season duration. The simulations reveal an increasing trend in the number of tracheids produced by cambium each year by 0.42 cells/year. Spring phenological phases (onset of cambial cell growth and tracheid enlargement) show significant shifts toward earlier occurrence in the year (for 0.28–0.34 days/year). In addition, there is a significant increase in simulated growth rates during entire growing season associated with the intra-annual redistribution of the dominant climatic controls over cambial activity. Results suggest that higher growth rates at treeline are driven by (i) temperature-stimulated intensification of spring cambial kinetics, and (ii) decoupling of summer growth rates from the limiting effect of low summer temperature due to higher frequency of climatically optimal days. Our results highlight that the cambial kinetics stimulation by increasing spring and summer temperatures and shifting spring phenology determine the recent growth trends of treeline ecosystems. Redistribution of individual climatic factors controlling cambial activity during the growing season questions the temporal stability of climatic signal of cold forest chronologies under ongoing climate change.

Impact of money supply onexchange rate in Nigeria: (1980-2011)

The paper examines the impact of money supply in determining the exchange rate of the currency with respect to fixed and flexible exchange rate policies in Nigeria. Time series data, sourced from Central Bank of Nigeria (CBN) was used. Money supply (MS) was decomposed to include Narrow Money Supply (M1), quasi money (Qm) and Broad Money Supply (M2). Econometric analysis based on the least squares procedure was conducted using E-View Version 7. Descriptive analysis was also carried out. It was found from the study that periods of floating exchange rate policy have influenced exchange rate positively even to a great extent and that quasi money showed a negative and significant sign on exchange rate, while narrow money exhibits a positive sign. Broad money supply indicates that expansionary monetary policy tends to diminish the Naira/ Dollar value. It is therefore recommended among others, that the Nigerian financial market in general and money market in particular should be strengthened in both depth and breath. The available money outside the banking system should be properly channelled for productive purposes in order to achieve the desired stability in the naira exchange rate and by extension growth in the Nigerian economy.

Phytotoxic condensed organic compounds are common in fast but not slow pyrolysis biochars

Biochar chemistry varies with feedstock and pyrolysis parameters: fast pyrolysis may not provide sufficient time for volatile compounds – some phytotoxic – to escape from biochar particles. Lettuce and radish seeds were treated with biochar leachate derived from 100 slow pyrolysis biochars (20 wood species, each pyrolyzed at 300–700 °C for 60 min), and 20 fast pyrolysis biochars (two species pyrolyzed at 500 and 550 °C for 1–5 min). Slow pyrolysis biochar leachates enhanced radicle extension growth by (60% for lettuce; 16% for radish), while fast pyrolysis biochar leachates inhibited radicle growth by (63% for lettuce; 8% for radish). Slow pyrolysis biochars showed higher concentrations of Ca, Mg, K, Fe, Mn, and Zn than fast pyrolysis biochars, whereas fast pyrolysis biochars generally showed higher concentrations of phytotoxic volatile fatty acids, such as acetic and pentanoic acid. These results suggest the importance of extended pyrolysis residence times in producing high-nutrient biochars free from toxicity effects.

Reduced pectin content of cell walls prevents stress-induced root cell elongation in Arabidopsis.

The primary cell walls of plants provide mechanical strength while maintaining the flexibility needed for cell extension growth. Cell extension involves loosening the bonds between cellulose microfibrils, hemicelluloses and pectins. Pectins have been implicated in this process, but it remains unclear if this depends on the abundance of certain pectins, their modifications, and/or structure. Here, cell wall-related mutants of the model plant Arabidopsis were characterized by biochemical and immunohistochemical methods and Fourier-transform infrared microspectroscopy. Mutants with reduced pectin or hemicellulose content showed no root cell elongation in response to simulated drought stress, in contrast to wild-type plants or mutants with reduced cellulose content. While no association was found between the degrees of pectin methylesterification and cell elongation, cell wall composition analysis suggested an important role of the pectin rhamnogalacturonan II (RGII), which was corroborated in experiments with the RGII-modifying chemical 2β-deoxy-Kdo. The results were complemented by expression analysis of cell wall synthesis genes and microscopic analysis of cell wall porosity. It is concluded that a certain amount of pectin is necessary for stress-induced root cell elongation, and hypotheses regarding the mechanistic basis of this result are formulated.

Quantifying effects of urban land-use patterns on flood regimes for a typical urbanized basin in eastern China

Abstract Artificial adjustment and urbanization are key factors of global change and have significant influences on hydrological processes. This study focuses on the effects of urban land-use patterns on flood regimes in a typical urbanized basin in eastern China. Comprehensive assessments of urban land-use patterns were implemented on three levels: total imperviousness area (TIA) magnitude, landscape configuration and relative location in the basin. Hydrologic Engineering Center's Modeling System (HEC-HMS) was calibrated and validated using four groups of parameters associated with land-use conditions. Fourteen flood events were simulated based on 10 land-use scenarios with different land-use patterns. The results indicate that floods are closely associated with three landscape pattern indicators. First, over the past 20 years, the impermeability rate has increased from 3.92 to 17.48%, with the landscape pattern converted from extension growth form to fill-up growth form after 2003. Second, the average flood peak discharge increased by 80% due to impermeable surfaces expansion, with minor floods more sensitive to the expansion than major floods. Third, the contribution of imperviousness expansion to peak discharge in the inner basin is more remarkable than downstream of the river basin, with the landscape pattern metrics of TIA, arable land and forest land displaying strong correlations with flood characteristics.