Full Yield Research Articles

Genome-wide association study for resistance to the southern root-knot nematode (Meloidogyne incognita) in soybean

Soybean [Glycine max (L.) Merrill] is one of the most important traded commodities for the world’s economy. However, soybean cultivation is often affected by biotic and abiotic factors that prevent the crop from attaining its full yield potential. With the advent of new tools for next-generation sequencing, the genomic knowledge gained from the study of this major oilseed crop has increased considerably in recent years. In this study, we performed a genotypic characterization of 188 plant introductions (PIs) and five cultivars using a genotyping-by-sequencing (GBS) approach and a phenotypic characterization for resistance/tolerance to the southern root-knot nematode, Meloidogyne incognita. We then performed a genome-wide association study (GWAS) for this important trait. From 46,196 SNP markers identified and validated on this set of genotypes, three were significantly associated with nematode resistance. Remarkably, all of these were in a single, very small (3.4 kb) region of chromosome 10. Most lines (48 out of 57) with the highest level of resistance shared the haplotype composed of the alleles associated with resistance at these three SNP loci. Interestingly, nine of the lines exhibiting a high level of resistance did not exhibit the “resistant haplotype” on Gm10. This suggests either that recombination has broken the association between the SNPs and the resistance locus or that resistance is conferred by a different locus altogether. In the latter case, these lines represent a putative alternative source of resistance, an important information for breeding programs.

Theoretical and numerical studies of elastic buckling and load resistance of double cross-arm pre-tensioned cable stayed buckling-restrained braces

This paper investigates the elastic buckling behaviour and load resistance of a double cross-arm pre-tensioned cable stayed buckling-restrained brace (DPCS-BRB) where an extra cross-arm is assigned within a longitudinal cable truss along its length. Naturally, the span and efficiency of the PCS-BRB can be increased and improved by adopting multiple cross-arms. Equilibrium method is utilised to derive the formula of elastic buckling load of a pin-ended DPCS-BRB, and the obtained results have been verified through FE analysis. It is found from theoretical derivations and FE analysis that there exists a single-wave symmetric and double-wave antisymmetric buckling modes in the DPCS-BRB, respectively. In addition, a negative linear correlation exists between the elastic buckling load and the initial pre-tensioning force of the cables in the DPCS-BRB. Furthermore, it has been explored through FE analysis that the optimal location of the cross-arms for achieving higher elastic buckling load as well as higher ultimate compressive load-carrying capacity is found to be a quarter length to each end of the DPCS-BRB. At last, the ultimate compressive load-carrying capacity of the DPCS-BRB is found to be directly proportional to its restraining ratio, and there exists a lower limit of the restraining ratio which ensures the core could reach its full cross-sectional yield load without overall instability of the DPCS-BRB. The investigation of the elastic buckling behaviour and ultimate compressive load-carrying capacity as well as the failure mechanism of the DPCS-BRB provides fundamentals to the further development of a comprehensive design method of the DPCS-BRB subjected to axial cyclic loads.

The Japanese pear ‘Hosui’ improves the fertility of European pears ‘Spadona’ and ‘Coscia’

Abstract In a previous work, it was found that ‘Spadona’ the main European pear cultivar grown in Israel, is semi-compatible with each of its three pollinators ‘Gentile’,‘Coscia’ and ‘Spadochina’. Thus, the full yield potential of these cultivars is not being realized. The Japanese pear (Pyrus pyrifolia) can fertilize European pears. In Israel, the environmental conditions for growing pears are sub-optimal for most pear cultivars. However, the Japanese pear ‘Hosui’ is well adapted to these conditions; moreover, it is fully compatible and flowers simultaneously with the cultivated European pears. In this work, we report on a 10-year evaluation of pollination of ‘Spadona’ and ‘Coscia’ pollinated by ‘Hosui’. The experiments were conducted in three stages: hand pollination; ‘bouquet insertion’; and a combined European-Asian pear orchard. The results indicate that this is a beneficial means for significantly improving fruit quality and quantity.

Cyclic tests of steel plate shear walls using box‐shape vertical boundary elements with or without infill concrete

SummaryThe steel plate shear wall (SPSW) is an effective lateral force resisting system in which unstiffened steel infill plates are connected to the horizontal and vertical boundary elements (VBEs) on all sides of the plates. The boundary elements must be designed to resist the tension field force of the infill panels. When the VBEs are made from a steel box section, the flange of each box VBE connected with the infill panels can be pulled out‐of‐plane by significant panel forces, called pull‐out action. This study investigates capacity design methods for box VBEs in SPSWs. Simplified fixed beam and portal frame models aim to estimate the pull‐out responses of the flange of the box sections with and without infill concrete, respectively. In this study, cyclic tests of three full‐scale two‐story SPSWs using box VBEs with or without the infill concrete are conducted. Inelastic pushover analyses of the finite element models are conducted. The tests and analytical results confirm that the proposed design methods, which aimed to prevent the full yield of the flange under the pull‐out action, are applicable. Furthermore, the test and analytical results suggest that the initial yielding of the flange of box VBEs under the collective effects of the pull‐out action on the flange, the gravity load, and the sway action on the SPSW represents a local yielding. A strict prohibition of the initial yielding on the flange under the aforementioned collective effects is not recommended for pursuing a cost‐effective design. Copyright © 2017 John Wiley & Sons, Ltd.

A simple procedure to simulate a smooth elastic-plastic transition in Cam-Clay models

A simple procedure is proposed to simulate a smooth transition from elastic to elastoplastic behaviour in Cam-Clay models. The procedure consists of the definition of an external constitutive surface where full yield is assumed, and an internal one that allows the definition of the position in which plastic strains start to appear before the external yield surface is reached. The comparison of the model results with different laboratory tests shows the validity of the procedure. The method considers one additional parameter with regard to a “standard” critical state model, and it can easily be implemented in existing integration modules.

Numerical studies of cyclic behavior and design suggestions on triple-truss-confined buckling-restrained braces

Abstract The cyclic behavior and design of a triple-truss-confined buckling-restrained brace (TTC-BRB) is investigated, especially when it is used in mega-frame high-rise buildings and long-span spatial structures as a long-span BRB. The TTC-BRB is formed by introducing an additional structural system of rigid truss frames to the outside of a common double-tube BRB in order to achieve a higher external restraining flexural stiffness as well as a high overall load-carrying capacity. An analytical method is utilized to derive a formula of the elastic buckling load of a pin-ended TTC-BRB, which is verified and modified through FE analyses. The effect of restraining ratio of the TTC-BRB on its cyclic behavior and failure mechanism is explored. The findings indicate that the TTC-BRB may have two different failure modes, namely in-plane and out-of-plane instability failures of the chord subjected to compression at the mid-span of the TTC-BRB. In addition, the load-carrying capacity of the TTC-BRB under cyclic loading is found to be proportional to the restraining ratio, and there exists a lower limit of the restraining ratio which ensures the core could reach its full cross-sectional yield load before overall instability failure of the TTC-BRB. Furthermore, in order for the TTC-BRB to be an energy dissipation type of BRBs, the lower limit requirement of the restraining ratio should be satisfied and its end constructional and strength design should be carefully carried out to avoid its premature failure. The investigation of the elastic buckling load and cyclic behavior as well as failure mechanism of the TTC-BRB provides fundamentals to the further development of a comprehensive design method of the TTC-BRB.

Accelerating early growth in miscanthus with the application of plastic mulch film

Miscanthus is a low input, high yielding C4 rhizomatous grass which could be used in Europe to meet renewable energy targets mandated in the EU2020 Directive. Currently, it takes three years for the crop to reach full yield potential at which point an economically viable biomass yield is returned by the crop. Reducing the time before an economically viable crop is produced would increase the profitability of the crop. Field trials were established over three years to investigate methods of accelerating early growth of Miscanthus x giganteus crops. Various plastic mulch film treatments, rhizome water pre-treatments, rhizome hormone pre-treatments and ridge treatments were trialled in this study. The hot water, water, hormone and ridge treatments did not increase establishment rates or accelerate early growth. Establishment rates, average height, stem numbers and biomass yield was increased through the application of plastic mulch film in the first growing season in 2014, 2015 and 2016 (P < 0.0001). There was a residual effect of plastic treatment with sustained increases in height, stem numbers per plant and biomass yields in the second growing season (P < 0.0001). There was a significant increase in stem numbers in the plastic treatment during the third growing season (P < 0.05). Net increases in both economic and GHG abatement were achieved through the application of plastic mulch film which offers a practical means of accelerating the time needed for miscanthus crops to reach their full yield potential.

Épocas de semeadura afetando índices morfofisiológicos de cultivares de arroz de terras altas

The expression of the full yield potential of crops depends on genetic factors, favorable environmental conditions and management. This study aimed to determine the effects of sowing dates on the solar radiation use efficiency (RUE), on morphophysiological indices, and on the grain yield of contrasting upland rice cultivars. The field experiment was conducted in the central region of Brazil in soils in Cerrado areas. The experiment had a 3 x 5 factorial randomized design with eight replications. The treatments consisted of combinations of three cultivars (BRS Primavera, BRSMG Curinga, and Douradao) with five sowing dates (11/09/2012, 22/10/2012, 11/28/2012, 21/12/2012, and 27/2/2013). All cultivars required less accumulated degree-days to reach the reproductive phase as the sowing was delayed. The lower biomass accumulation and leaf area index (LAI) of the three cultivars occurred on the earlier sowing date, which may have been a result of lower RUE. The assimilate partitioning to leaves and stems was similar among cultivars, but the translocation rate of carbohydrates to the panicle was higher in the cultivars BRSMG Curinga and Douradao. The cultivars differed in the total number of grains per area, with the highest values found in Douradao and the lowest in BRS Primavera. The highest grain yields were obtained in sowing dates covering the traditional period of sowing upland rice, which is October to December.

Epitaxial Lift-Off and Transfer of III-N Materials and Devices from SiC Substrates

In this paper, electrical characterization results of N-polar GaN high-electron-mobility transistors that have been released from a 6H-SiC wafer and manually transferred to a Si wafer using a novel epitaxial lift-off (ELO) technique are presented. This recently developed ELO method uses a thin sacrificial layer of Nb2N, a hexagonal epitaxial conductor with less than 1% lattice mismatch to 4H- and 6H-SiC, to serve as the template for III-N device heterostructure growth. Measured results of transferred devices indicate that electron transport properties and low power density electrical performance are nominally unchanged relative to values measured before release. This technique has several advantages over competing ELO techniques, such as the well-known smart cut method, including bonding-ready released material with atomically-smooth backsides (≤ 0.5 nm rms), easy substrate reclaim with indefinite recycling potential, and a transfer process that can be performed after full front-side device processing and yield screening has been completed.

Evaluation of water-limited cropping systems in a semi-arid climate using DSSAT-CSM

Water is the major factor limiting crop production in western Kansas due to declining groundwater levels in the Ogallala aquifer resulting from withdrawals for irrigation exceeding recharge rates coupled with erratic semi-arid rainfall. Study objectives were to assess yield and water productivity of water limited cropping systems in western Kansas using DSSAT-CSM (Decision Support System for Agrotechnology Transfer Cropping Systems Model). The cropping systems evaluated included continuous (corn, wheat, and grain sorghum) and rotation (corn-wheat, corn-wheat-grain sorghum, and corn-wheat-grain sorghum-corn). Results showed that the model adequately reproduced measured days to flowering and maturity as well as yield and aboveground biomass of all three crops. Crop rotation improved water productivity of corn. Under deficit irrigation, corn in rotation produced higher yields, crop water productivity, and irrigation water use efficiency compared to continuous corn, implying that crop rotation is a better option under limited well capacities. Under full irrigation, yield and water productivity of continuous wheat were lower than wheat in rotation. In contrast, continuous wheat yields under deficit irrigation were better than under crop rotation. Deficit irrigation substantially improved irrigation water use efficiency of grain sorghum under both continuous and crop rotations. Long–term average grain sorghum yields under rotation were higher than those of continuous grain sorghum. Indicating grain sorghum should be grown in rotation under deficit irrigation. This research did not simulate the impacts of pests, weeds and diseases, hail and freeze damage on crop yield. However, the study identifies cropping systems that are more likely to produce highest water productivity under semi-arid climate similar to that in western Kansas.

Transcriptome Sequencing Identified Genes and Gene Ontologies Associated with Early Freezing Tolerance in Maize.

Originating in a tropical climate, maize has faced great challenges as cultivation has expanded to the majority of the world's temperate zones. In these zones, frost and cold temperatures are major factors that prevent maize from reaching its full yield potential. Among 30 elite maize inbred lines adapted to northern China, we identified two lines of extreme, but opposite, freezing tolerance levels—highly tolerant and highly sensitive. During the seedling stage of these two lines, we used RNA-seq to measure changes in maize whole genome transcriptome before and after freezing treatment. In total, 19,794 genes were expressed, of which 4550 exhibited differential expression due to either treatment (before or after freezing) or line type (tolerant or sensitive). Of the 4550 differently expressed genes, 948 exhibited differential expression due to treatment within line or lines under freezing condition. Analysis of gene ontology found that these 948 genes were significantly enriched for binding functions (DNA binding, ATP binding, and metal ion binding), protein kinase activity, and peptidase activity. Based on their enrichment, literature support, and significant levels of differential expression, 30 of these 948 genes were selected for quantitative real-time PCR (qRT-PCR) validation. The validation confirmed our RNA-Seq-based findings, with squared correlation coefficients of 80% and 50% in the tolerance and sensitive lines, respectively. This study provided valuable resources for further studies to enhance understanding of the molecular mechanisms underlying maize early freezing response and enable targeted breeding strategies for developing varieties with superior frost resistance to achieve yield potential.

Theoretical analysis and numerical simulation of development length of straight steel fiber in cementitious materials

In fiber-reinforced concrete, it is important to choose an appropriate length in each fiber to develop its full yield strength without a failure in the bond strength between the fiber and the concrete. This length is called the fiber development length, Ldf. The bond capacity is evaluated between the fiber and the concrete using the pull-out tests. This test evaluates the bond capacity of various types of steel fiber surfaces relative to a specific embedded length. If the steel fiber is smooth and straight, the distribution of tensile stresses will be uniform around the fiber at a specific section and varies along the anchorage length of the fiber and at a radial distance from the surface of the fiber. Pull-out tests can be performed on an embedded straight steel fiber in concrete matrix, in this case, the tensile force, P, is increased gradually and the number of cracks and their spacings and widths is recorded. The bond stresses vary along the fiber length between the cracks. The strain in the steel fiber is maximum at the cracked section and decreases toward the middle section between cracks. If the embedded length of the straight steel fiber is greater than the development length, the steel fiber may yield, leaving some length of the fiber in the concrete. The linear elastic behavior of the fiber-matrix system is interrupted by interface debonding which occurs due to overall weak bonding between the concrete matrix and the surface of the steel fiber. This paper introduces new developed shear lag model and explains simplified method to find the development length of straight steel fiber in concrete matrix using finite element model and analysis of shear lag stresses, where the maximum tension force which is applied on the steel fiber is resisted by another internal force related with the ultimate average bond stress, steel fiber diameter and its yield strength.

Yield gap analysis of US rice production systems shows opportunities for improvement

Many assessments of crop yield gaps based on comparisons to actual yields suggest grain yields in highly intensified agricultural systems are at or near the maximum yield attainable. However, these estimates can be biased in situations where yields are below full yield potential. Rice yields in the US continue to increase annually, suggesting that rice yields are not near the potential. In the interest of directing future efforts towards areas where improvement is most easily achieved, we estimated yield potential and yield gaps in US rice production systems, which are amongst the highest yielding rice systems globally. Zones around fourteen reference weather stations were created, and represented 87% of total US rice harvested area. Rice yield potential was estimated over a period of 13–15 years within each zone using the ORYZA(v3) crop model. Yield potential ranged from 11.5 to 14.5Mgha−1, while actual yields varied from 7.4 to 9.6Mgha−1, or 58–76% of yield potential. Assuming farmers could exploit up to 85% of yield potential, yield gaps ranged from 1.1 to 3.5Mgha−1. Yield gaps were smallest in northern California and the western rice area of Texas, and largest in the southern rice area of California, southern Louisiana, and northern Arkansas/southern Missouri. Areas with larger yield gaps exhibited greater annual yield increases over the study period (35.7kgha−1year−1 per Mg yield gap). Adoption of optimum management and hybrid rice varieties over the study period may explain annual yield increases, and may provide a means to further increase production via expanded adoption of current technologies.

Hydrogen generation from aluminum hydride for wearable polymer electrolyte membrane fuel cells

Aluminum hydride (AlH3) has been identified as a promising H2 storage material for fuel cell systems and offers a significant weight savings over conventional Li-ion batteries, due its high H2 storage capacity and simple balance of plant requirements for H2 generation. This work reports on the development and characterization of a novel, wearable AlH3 based PEM fuel cell system. System characterization revealed an unexpectedly low energy density value, 25% lower than anticipated, (436 Wh kg−1 vs. 582 Wh kg−1 for 1440 Wh) due in part to a previously unpublished phenomenon of incomplete α-AlH3 thermolysis. Based on literature reports, complete thermolysis was expected to occur at <180 °C, however this work reports on conditions where the full H2 yield cannot be obtained despite high temperature (>250 °C) exposure. This work provides an experimental characterization of this phenomenon and quantitatively describes it by developing a new model in the framework of the Avrami–Erofeev phase transformation model, which can be utilized for the optimum design of high energy density AlH3 cartridges.

Interpreting sedimentation dynamics at Longxi catchment in the Three Gorges Area, China, using Cs-137 activity, particle size and rainfall erosivity

Reservoir sedimentation dynamics were interpreted using Cs-137 activity, particle size and rainfall erosivity analysis in conjunction with sediment profile coring. Two sediment cores were retrieved from the Changshou reservoir of Chongqing, which was dammed in 1956 at the outlet of Longxi catchment in the Three Gorges Area using a gravity corer equipped with an acrylic tube with an inner diameter of 6 cm. The extracted cores were sectioned at 2 cm intervals. All sediment core samples were dried, sieved (< 2 mm) and weighed. Cs-137 activity was measured by gamma-ray spectrometry. The particle size of the core samples was measured using laser particle size granulometry. Rainfall erosivity was calculated using daily rainfall data from meteorological records and information on soil conservation history was collated to help interpret temporal sedimentation trends. The peak fallout of Cs-137 in 1963 appeared at a depth of 84 cm in core A and 56 cm in core B. The peaks of sand contents were related to the peaks of rainfall erosivity which were recorded in 1982, 1989, 1998 and 2005, respectively. Sedimentation rates were calculated according to the sediment profile chronological controls of 1956, 1963, 1982, 1989, 1998 and 2005. The highest sedimentation rate was around 2.0 cma (TM) a(-1) between 1982 and 1988 when the Chinese national reform and the Household Responsibility System were implemented, leading to accelerated soil erosion in the Longxi catchment. Since 1990s, and particularly since 2005, sedimentation rates clearly decreased, since a number of soil conservation programs have been carried out in the catchment. The combined use of Cs-137 chronology, particle size and rainfall erosivity provided a simple basis for reconstructing reservoir sedimentation dynamics in the context of both physical processes and soil restoration. Its advantages include avoiding the need for full blown sediment yield reconstruction and the concomitant consideration of core correlation and corrections for autochthonous inputs and reservoir trap efficiency.

A Screening Method for Prevention of Ratcheting Strain Derived From Movement of Temperature Distribution

In this paper, we simplify the existing method and propose a screening method to prevent thermal ratcheting strain in the design of practical components. The proposed method consists of two steps to prevent the continuous accumulation of ratcheting strain. The first step is to determine whether all points through the wall thickness are in the plastic state. This is based on an equivalent membrane stress, which comprises the primary stress and the secondary membrane stress. When the equivalent stress exceeds the yield strength in some regions of the cylinder, the axial lengths of these regions are measured for the second step. The second step is to determine whether the accumulation of the plastic strain saturates. For this purpose, we define the screening criteria for the length of the area with full section yield state. When this length is sufficiently small, residual stress is generated in the direction opposite to the plastic deformation direction. As a result of residual stress, further accumulation of the plastic deformation is suppressed, and finally shakedown occurs. To validate the proposed method, we performed a set of elastoplastic finite element method (FEM) analyses, with the assumption of elastic perfectly plastic material. Not only did we investigate about the effect of the axial length of the area with full section yield state but also we investigated about effects of spatial distribution of temperature, existence of primary stress, and radius thickness ratio.

Economics analysis on yield of cotton as influenced by sulphur and micronutrients

Cotton is still the principal commercial crop touching the country’s economy at several points. It is also an important commercial crop of Karnataka and cultivated on an area of 4.78 lakh ha with a production of 6.77 lakh bales (Anonymous, 2003). With the introduction of high yielding and fertilizer responsive varieties, the practices of using large amounts of high analysis macronutrient fertilizers with much decreased use of organic manures and little recycling of crop residues led to micronutrient hunger in many crops. Generally the need of the micronutrients has been essentially and entirely met through its native reserve in the soil (Singh, 1999), Inspite of liberal application of N, P and K fertilizers, normal growth of high yielding varieties of crop could not be achieved due to little appreciation of the use of secondary and micronutrients. High fertilizer responsive varieties can express their full yield potential only when limiting trace elements fertilizers are also applied along with NPK fertilizers. Since, information on economic aspects of production of cotton (RAHB-87) is lacking in northern transitional zone (Zone-8) of Karnataka, the present study was carried out to know the optimum dose of nutrients, required to produce maximum yield which economically viable. A field experiment was conducted on medium black soil having initial organic carbon content of 0.58 per cent, pH 7.30, available nitrogen phosphorus and potassium content of soil were 315, 22.0, 390 kg/ha, respectively. The experiment was laid out in randomized block design in 3 replications with nine treatment combinations. Results revealed that treatment (T 9 ) receiving combined application of sulphur, iron, zinc each at 50 kg per ha recoded highest seed cotton yield (25.12 q/ha) which was on par with treatment (T 8 ) receiving combined application of sulphur, iron and zinc each at 25 kg per ha. These two treatments were significantly superior over control. Economic analysis of the system revealed that, Economics analysis on yield of cotton as influenced by sulphur and micronutrients

El Niño Southern Oscillation Effects on Dryland Crop Production in the Texas High Plains

Risk averse dryland crop management in the U.S. southern High Plains stabilizes annual yields, however in some years the full yield potential is unrealized thereby reducing the overall cropping system productivity. Equatorial Pacific sea surface temperature anomalies (SSTA) systematically couple with the atmosphere to produce predictable El Niño‐Southern Oscillation (ENSO) weather in much of North America that could be exploited for improved crop management. Our objective was to evaluate ENSO effects on site‐specific growth and yield of wheat (Triticum aestivum L.) and grain sorghum [Sorghum bicolor (L.) Moench] in a dryland wheat–sorghum–fallow (WSF) rotation from 1954 to 2011. Measurements from contour farmed terraces were grouped by common ENSO phase years based on 3‐mo classification ending in June (April–June, AMJ) or August (June–August, JJA) that permits timely management of sorghum or wheat. Compared with years classified during September to November (SON) or mature ENSO phases, the JJA classification identified 78 and 68% of common La Niña and El Niño years, respectively, and may have potential application to wheat management. Poor agreement between SON and AMJ phase classifications reduced common La Niña and El Niño years to 61 and 53% respectively, and may limit grain sorghum management. Compared with La Nina, wheat growing‐season precipitation increased 31% for El Nino and contributed to a 55% increase in detrended grain yield differences. For the Texas High Plains, the ENSO phase effects on sorghum grain yield were less pronounced than for wheat, suggesting ENSO based management is better suited to wheat.Core Ideas El Niño phases affected site‐specific rain and crop yield of a 58‐yr field test. Wheat but not sorghum yields responded significantly to El Niño conditions. Predicted El Niño phase has the potential to guide site‐specific wheat management.

Flexural Capacity of Composite Beams Subjected to Fire: Fiber-Based Models and Benchmarking

This paper presents the development and verification of a fiber-based modeling technique to predict the fundamental moment–curvature–temperature (M–Φ–T) response of a composite steel beam cross-section in fire conditions. Experimental investigations and 3D finite element models can provide insight to the behavior of composite beams subjected to fire. However, these experimental and numerical approaches can be expensive and cumbersome for conducting extensive parametric studies. Therefore, a simpler 2D fiber-based modeling technique was developed for calculating the flexural behavior and moment capacity of composite steel beams at elevated temperatures. This simpler fiber-based approach can be implemented relatively easily and independently by designers. The 2D fiber-based approach is a simplified model that accounts for temperature dependent (steel and concrete) material properties and the level of slip at the concrete-to-steel interface at elevated temperature. The model does not account for membrane action or rupture of reinforcement, but it can be used to calculate the moment capacity of partially composite steel beams without an extensive finite element analysis. The fiber-based model was benchmarked using experimental results from composite steel beam tests subjected to fire, illustrating that it was capable of predicting moment capacity corresponding to the applicable limit state (i.e., full yield of the steel beam, concrete crushing or limiting stud slip) at elevated temperature. The fiber model predictions were typically conservative, and on average, the predicted moment capacity was 95% of the capacity determined from the experimental tests.

Growing sensitivity of maize to water scarcity under climate change.

Climate change can reduce crop yields and thereby threaten food security. The current measures used to adapt to climate change involve avoiding crops yield decrease, however, the limitations of such measures due to water and other resources scarcity have not been well understood. Here, we quantify how the sensitivity of maize to water availability has increased because of the shift toward longer-maturing varieties during last three decades in the Chinese Maize Belt (CMB). We report that modern, longer-maturing varieties have extended the growing period by an average of 8 days and have significantly offset the negative impacts of climate change on yield. However, the sensitivity of maize production to water has increased: maize yield across the CMB was 5% lower with rainfed than with irrigated maize in the 1980s and was 10% lower (and even >20% lower in some areas) in the 2000s because of both warming and the increased requirement for water by the longer-maturing varieties. Of the maize area in China, 40% now fails to receive the precipitation required to attain the full yield potential. Opportunities for water saving in maize systems exist, but water scarcity in China remains a serious problem.