bluuebunny/crossref_metadata_2025_split huggingface dataset:
Atmospheric Circulation Response to an Instantaneous Doubling of Carbon Dioxide. Part I: Model Experiments and Transient Thermal Response in the Troposphere*
Authors: Wu Yutian , Seager Richard , Ting Mingfang , Naik Naomi , Shaw Tiffany A. 
Published: December 2011

AbstractThis study aims to understand the dynamical mechanisms driving the changes in the general circulation of the atmosphere due to increased carbon dioxide (CO2) by looking into the transient step-by-step adjustment of the circulation. The transient atmospheric adjustment is examined using the National Center for Atmospheric Research Community Atmosphere Model, version 3, coupled to a slab ocean model, and the CO2 concentration in the atmosphere is uniformly and instantaneously doubled. The thermal structure and circulation response is well established after one year of integration, with the magnitudes gradually increasing afterward toward quasi equilibrium. Tropical upper-tropospheric warming occurs in the first month. The expansion of the warming in the mid- and upper troposphere to the subtropics occurs later and is found to be primarily dynamically driven due to the intensification of transient eddy momentum flux convergence and resulting anomalous descending motion in this region. The poleward displacement of the midlatitude tropospheric jet streams occurs together with the change in eddy momentum flux convergence, but only after the intensification of the subpolar westerlies in the stratosphere. The results demonstrate the importance of the tropospheric eddies in setting up the extratropical tropospheric response to global warming.
Dynamic-Model-Based Seasonal Prediction of Meteorological Drought over the Contiguous United States
Authors: Yoon Jin-Ho , Mo Kingtse , Wood Eric F. 
Published: December 2011

Abstract
A simple method was developed to forecast 3- and 6-month standardized precipitation indices (SPIs) for the prediction of meteorological drought over the contiguous United States based on precipitation seasonal forecasts from the NCEP Climate Forecast System (CFS). Before predicting SPI, the precipitation (P) forecasts from the coarse-resolution CFS global model were bias corrected and downscaled to a regional grid of 50 km. The downscaled CFS P forecasts, out to 9 months, were appended to the P analyses to form an extended P dataset. The SPIs were calculated from this new time series. Five downscaling methods were tested: 1) bilinear interpolation; 2) a bias correction and spatial downscaling (BCSD) method based on the probability distribution functions; 3) a conditional probability estimation approach using the mean P ensemble forecasts developed by J. Schaake, 4) a Bayesian approach that bias corrects and downscales P using all ensemble forecast members, as developed by the Princeton University group; and 5) multimethod ensemble as the equally weighted mean of the BCSD, Schaake, and Bayesian forecasts. For initial conditions from April to May, statistical downscaling methods were compared with dynamic downscaling based on the NCEP regional spectral model and forecasts from a high-resolution CFS T382 model. The skill is regionally and seasonally dependent. Overall, the 6-month SPI is skillful out to 3–4 months. For the first 3-month lead times, forecast skill comes from the P analyses prior to the forecast time. After 3 months, the multimethod ensemble has small advantages, but forecast skill may be too low to be useful in practice.
Novel Synthetic Method for Metalloporphyrins with Inorganic Metal Salts in High-temperature Water
Authors: Sato Takafumi , Ebisawa Katsutoshi , Ito Satoshi , Sue Kiwamu , Itoh Naotsugu 
Published: December 2011

Abstract
Cobalt, nickel, copper, and oxidovanadium(2+) could be incorporated into nonpolar tetraphenyl porphyrin by using feed materials as metal sulfate, nitrate, and chloride salts and reaction in high-temperature water (423 to 673 K). Yields of metalloporphyrins increased to 94% at 673 K, which indicates that the dissolution of porphyrin and reaction of the metal salts are enhanced in high-temperature water.
Sequential Suzuki–Miyaura Cross-coupling Reactions of 4-Halopyrazolyl MIDA 3-Boronates: A Modular Synthetic Entry to 3,4-Bis(hetero)aromatic Pyrazoles
Authors: Delaunay Thierry , Es-Sayed Mazen , Vors Jean-Pierre , Monteiro Nuno , Balme Geneviève 
Published: December 2011

Abstract
The 1,3-dipolar cycloaddition of N-arylsydnones with ethynyl MIDA boronate produces mixtures of the corresponding regioisomeric pyrazolyl 3(4)-boronates, with the pyrazolyl 3-boronates predominating by a factor of 7:3. Further C-4 iodination of the latter opened access to 4-iodopyrazolyl MIDA 3-boronates as valuable scaffolds for the elaboration of unsymmetrically 1,3,4-trisubstituted pyrazole derivatives via Suzuki cross-coupling reactions.
Diacenaphtho[1,2-b;1′,2′-d]silole and -pyrrole
Authors: Nagasaka Yoshiharu , Kitamura Chitoshi , Kurata Hiroyuki , Kawase Takeshi 
Published: December 2011

Abstract
π-Extended silole and pyrrole analogs fused with two acenaphthylene units were synthesized from 2,2′-dibromo-1,1′-biacenaphthylene. The pyrrole was obtained as a stable compound, while the silole was thermally stable, but highly acid-sensitive purple crystals. The molecular structures reveal that both heteroles have a planar π-system and stack to form a head-to-tail dimer structure. Observed electronic and electrochemical properties obviously indicate low LUMO energy level of the silole and high HOMO level of the pyrrole as predicted by DFT calculations.
Selective Dimerization of Aryl-substituted Terminal Alkynes on Bis(indenyl)zirconocene Derivatives
Authors: Ren Shenyong , Seki Takashi , Necas David , Shimizu Hiroyuki , Nakajima Kiyohiko , Kanno Ken-ichiro , Song Zhiying , Takahashi Tamotsu 
Published: December 2011

Abstract
Dimerization of aryl-substituted terminal alkynes on indenyl zirconium complexes occurred in a selective way. 1,4-Aryl-1,3-diene derivatives were formed exclusively after hydrolysis. It is in sharp contrast to the reaction on [Cp2Zr] complexes.
Synthesis of Co-oligomers of Thiophene Derivatives from Oligoynes via Zirconacyclopentadiene
Authors: Payra Debabrata , Song Zhiyi , Kanno Ken-ichiro , Takahashi Tamotsu 
Published: December 2011

Abstract
For the formation of oligothiophenes or thiophene co-oligomers, a preconnected method using zirconacyclopentadienes was demonstrated. Oligoynes of 4,4-bis(butoxymethyl)-1,6-heptadiyne linked through bithiophene were prepared where all components and diyne moieties were connected in advance before converting to zirconacyclopentadiene-containing precursors. Treatment of the reactive zirconacyclopentadienes in the preconnected precursors with acid, dimethyl acetylenedicarboxylate or sulfur monochloride afforded different oligothiophenes or thiophene co-oligomer derivatives.
Cross Coupling on Gold Nanoparticles. Effect of Reinforced Affinity of Organic Group with Bipedal Thiol
Authors: Sugie Atsushi , Kumazawa Kenta , Hatta Tomomi , Kanie Kiyoshi , Muramatsu Atsushi , Mori Atsunori 
Published: December 2011

Abstract
Bipedal thiol, whose end is modified with iodoarene, is synthesized and introduced onto the surface of gold nanoparticles. The obtained nanoparticles allow the Suzuki–Miyaura and Sonogashira cross-coupling reactions to form the carbon–carbon bond on the surface of the nanoparticle without serious aggregation under harsh conditions.
Protonation-induced Cyclization of 1,8-Bis(arylethynyl)anthraquinones: Monopyrylium Salt Formation and Intensification of Donor–Acceptor Interaction
Authors: Rao Koya Prabhakara , Kondo Mio , Sakamoto Ryota , Kusamoto Tetsuro , Kume Shoko , Nishihara Hiroshi 
Published: December 2011

Abstract
We previously reported protonation-induced double cyclization reaction of 1,4-Ar2Aq and 1,5-Ar2Aq (Ar2Aq: bis(arylethynyl)anthraquinone) with strong acid HX that generated the corresponding dipyrylium salts [1,4-Ar2Pyl2]X2 and [1,5-Ar2Pyl2]X2. In this communication we disclose the protonation reactions of 1,8-Fc2Aq (Fc: ferrocenyl), 1,8-Am2Aq (Am: 4-N,N-bis(4-methoxyphenyl)aminophenyl), and 1,8-AmFcAq, which is the first example of heterodonor molecules in the Ar2Aq series, and synthesized by means of stepwise Sonogashira–Hagihara cross-coupling reactions. In contrast to the 1,4-Ar2Aq and 1,5-Ar2Aq series, 1,8-Ar2Aq undergoes protonation-induced single cyclization, so that it is converted into the corresponding monopyrylium salt [1,8-Ar2Pyl]X. [1,8-Ar2Pyl]X features an extremely small HOMO–LUMO gap (0.50–0.73 V), ascribable to the significant lowering of the LUMO level upon the pyrylium formation.
Grain Yield Response to Planting Density in Forage Rice with a Large Number of Spikelets
Authors: Nakano H. , Morita S. , Kitagawa H. , Wada H. , Takahashi M. 
Published: December 2011

ABSTRACTBecause forage rice (Oryza sativa L.) must be cost‐competitive with other forage crops, high grain yield is essential. The objective of the present study was to determine the effects of planting density (11, 25, or 100 hills m−2) and N application method (the 79‐21N method, with 79% of the N applied before the panicle initiation stage and 21% after, or the 36‐64N method, 36% before and 64% after) on grain yield and its components in the cultivar Mizuhochikara, which produces an unusually large number of spikelets per square meter. Grain yield was not different between N application methods but increased from 799 g m−2 to 870 g m−2 with increasing planting density. The number of spikelets per square meter was not strongly influenced by the planting densities. The percentage of filled spikelets and the 1000‐grain weight was higher at 100 and 25 hills m−2 than at 11 hills m−2. The amount of nonstructural carbohydrate (NSC) in the leaf sheaths plus stems per square meter at the full heading stage was larger at 100 and 25 hills m−2 than at 11 hills m−2. The percentages of both primary and secondary spikelets increased with increasing planting density, whereas that of tertiary spikelets decreased. Grain weight per spikelet was generally higher at primary and secondary spikelets than at tertiary spikelets. At each position in the panicle, grain weight per spikelet was heavier at 100 and 25 hills m−2 than at 11 hills m−2. Thus, dense planting may increase the grain yield, the percentage of filled spikelets, and the 1000‐grain weight by increasing NSC at full heading stage and decreasing the number of tertiary spikelets even at a large number of spikelets per square meter in Mizuhochikara.
Effects of Temperature and Light on Photosynthetic Heterosis of an Upland Cotton Hybrid Cultivar
Authors: Zeng Bin , Xu Xiaoming , Zhou Shixiang , Zhu Chunshen , Tang Canming 
Published: December 2011

ABSTRACTThe hybrid vigor of crops is related to photosynthesis. However, the effects of environmental factors on the heterosis of the net photosynthesis rate (Pn) of upland cotton (Gossypium hirsutum L.) hybrids remain largely unknown. The objective of this study was to identify the relationship between the heterosis of Pn and temperature and light intensity by using reciprocal hybrids of upland cotton (G. hirsutum cv. Xiangzamian 3) and their corresponding parental lines at the flowering‐boll stage. Both the effects of heterosis on the diurnal variations of Pn throughout the day and Pn responses to light under different temperatures in the fourth leaves from the tops of the main stems were surveyed. The maximum values of Pn for all plants were observed at 1000 h. A reduction in Pn was noticeable between 1000 and 1200 h. The maximum heterosis of the obverse F1 and reverse F1 of Pn was observed between 1300 and 1700 h under high light intensities (>1000 μmol m−2 s−1), high temperatures (≥40°C), and low relative humidity (≤40%). The effects of heterosis on the self‐cooling abilities of the F1 leaves may be related to the heterosis of Pn in the hybrids that were under heat stress. The resistance of hybrids to high temperatures under high light intensities may act as the heterotic mechanism affecting cotton photosynthetic rates and may also allow for a new method of selecting cotton cultivars with high Pn.
Molecular Variation Among and Within Improved Cultivars in the U.S. Cotton Germplasm Collection
Authors: Hinze Lori L. , Dever Jane K. , Percy Richard G. 
Published: December 2011

ABSTRACTMany cotton (Gossypium spp.) accessions conserved in the U.S. Cotton Germplasm Collection are not characterized sufficiently to encourage breeders’ interest in using these accessions. This study was conducted to determine the genetic variability of several groups of improved Gossypium hirsutum L. accessions and how this variability can be used to enhance current breeding programs. These groups were selected based on region or era of development and included cultivars from China and northern and southern Africa and obsolete and recent U.S. cultivars. Both inter‐ and intracultivar diversity were observed among these cultivars, but larger patterns of diversity based on region or era of development were poor or lacking. Heterozygosity levels averaged 44% for all groups, with Chinese cultivars showing the lowest polymorphism (72%) and polymorphism information content (PIC) values (0.332). The African cultivars showed the highest levels of intracultivar molecular variation with 13.4% polymorphic loci. The majority of molecular diversity was found within groups (62.2%) and within cultivars (31.0%) rather than among groups (6.8%). The average genetic similarity between cultivars was 0.832, ranging from 0.675 to 0.999. This information will provide cotton breeders with more accurate guidance in the selection of unique and desirable accessions to introduce diversity that possibly will reduce vulnerability to disease and insect pressures and could provide improvements for yield, agronomic, and fiber quality traits.
Comparative Quantitative Trait Loci Mapping for Gibberella Ear Rot Resistance and Reduced Deoxynivalenol Contamination across Connected Maize Populations
Authors: Martin M. , Miedaner T. , Schwegler D. D. , Kessel B. , Ouzunova M. , Dhillon B. S. , Schipprack W. , Utz H. F. , Melchinger A. E. 
Published: December 2011

ABSTRACTGibberella ear rot (GER) of maize (Zea mays L.) caused by Fusarium graminearum Schwabe leads to yield loss and contamination with deoxynivalenol (DON), the most commonly detected mycotoxin. To enhance the efficiency of marker‐assisted selection (MAS), it is necessary to identify quantitative trait loci (QTL), which are effective across different genetic backgrounds. The objectives of the present study were to (i) map QTL for GER resistance and reduced DON contamination, (ii) examine the congruency of QTL across four connected populations (three from this study and one from an earlier study), and (iii) draw conclusions about the prospects of MAS. The populations under study comprised doubled haploid (DH) lines derived from crosses of four flint inbreds. The traits were recorded under artificial inoculation. Estimates of genotypic variances were significant and heritabilities were moderately high to high. We mapped QTL together explaining 21 to 49% of for GER severity and 19 to 30% for DON concentration. Colocalized QTL for GER resistance and reduced DON contamination were identified in each mapping population. Further, QTL located at similar positions were detected across three populations in two chromosomal regions and across two populations in additional two regions. The study indicated that a combination of classical phenotypic selection and MAS is a promising strategy to breed maize for GER resistance and reduced DON contamination.
Genetic Gains in Grain Yield and Physiological Traits of Winter Wheat in Shandong Province, China, from 1969 to 2006
Authors: Xiao Y. G. , Qian Z. G. , Wu K. , Liu J. J. , Xia X. C. , Ji W. Q. , He Z. H. 
Published: December 2011

ABSTRACTKnowledge on the changes in yield potential and associated physiological traits is essential for understanding the main yield‐limiting factors and guiding future breeding strategies. Our objective was to identify physiological traits associated with genetic gains in grain yield of winter wheat (Triticum aestivum L.) in Shandong province, China. Thirteen milestone cultivars and two advanced lines released from 1969 to 2006 were examined over 3 yr at Tai'an during 2006 to 2009. The genetic gain in grain yield was 62 kg ha−1 yr−1, largely associated with increased kernels per square meter, biomass, and harvest index (HI) and reduced plant height. Significant genetic changes were also observed especially for apparent leaf area index (LAI) at heading and anthesis, chlorophyll content (Chl) at anthesis, photosynthesis rate during grain filling, and stem water‐soluble carbohydrate (WSC) content at anthesis. Comparing genotypes having Rht‐D1b and others with both Rht‐D1b and Rht8c (Rht‐D1b+Rht8c) showed increased grain yield, thousand kernel weight, kernels per spike, kernel weight per spike, HI, canopy temperature depression, and Chl at anthesis and LAI at heading with the latter but no difference in height. The results suggested that genetic gains in grain yield in Shandong province were mainly contributed by increases in kernels per square meter and biomass, which were achieved through improving crop photosynthesis at and after heading, and the source for grain filling may have benefited from increased WSC in stems at anthesis.
Screening Methods for Aluminum Tolerance in Alfalfa
Authors: Khu Dong‐Man , Reyno Rafael , Brummer E. Charles , Monteros Maria J. 
Published: December 2011

ABSTRACTReliable phenotypic assays are essential to identify genetic variation for factors limiting crop productivity. Aluminum in the soil is highly phytotoxic and is a major limitation to crop production. Current methods to evaluate Al tolerance in alfalfa (Medicago sativa L.) based on root characteristics are time consuming, labor intensive, and subject to microenvironmental variation. Our objective was to develop two rapid whole‐plant assays, one in culture media and one in soil, to evaluate acid and Al tolerance in alfalfa. The culture‐media method involved measuring root growth and architecture 2 wk after growing the plants in media at pH 7.0 without Al, pH 4.0 without Al, and pH 4.0 with Al. The greenhouse‐based soil method is simpler, faster, and more efficient than previously used soil assays. The two assays produced similar results, consistently distinguishing between Al‐sensitive and Al‐tolerant alfalfa genotypes in accord with previously described assays. These whole‐plant assay methods will enable the screening of breeding populations to improve Al tolerance and the dissection of the genetic determinants underlying variation in tolerance responses.
Winter Wheat and Red Clover Intercrop Response to Tillage and Compost Amendment
Authors: Blaser Brock C. , Singer Jeremy W. , Gibson Lance R. 
Published: December 2011

ABSTRACTFrost‐seeding red clover (Trifolium pratense L.) into winter cereals is an efficient establishment method, although performance under contrasting soil management practices remains unclear. Wheat and intercropped red clover productivity were evaluated in intensive tillage (IT), moderate tillage (MT), and no tillage (NT) with and without compost amendment in a corn (Zea mays L.)–soybean [Glycine max (L.) Merr.]–winter wheat (Triticum aestivum L.) and red clover rotation between 2005 and 2010. Wheat yields were not affected by tillage system and averaged 3.80 Mg ha−1 but were 10% higher in compost amended soil compared to no compost. Red clover plant density and dry matter (DM) at cereal grain harvest averaged 127 plants m−2 and 32 g m−2 and were not affected by tillage or amendment treatments. Maximum wheat canopy light interception was attained in late May to early June and ranged from 84 to 91% and typically exceeded 77% light interception for at least 22 d. Red clover root DM increased on average 378% between wheat harvest and 40 d after harvest compared with a 64% average increase in red clover root length. Red clover shoot:root averaged 8.5 at wheat harvest compared with 11.2 40 d after wheat harvest. Producers using this wheat and red clover intercrop should expect no difference in wheat yield or red clover productivity when using IT, MT, or NT.
Genetic Diversity of Rapeseed Accessions from Different Geographic Locations Revealed by Expressed Sequence Tag‐Simple Sequence Repeat and Random Amplified Polymorphic DNA Markers
Authors: Li Wei , Jiang Wei , Zhao Hui xian , Vyvadilova Miroslava , Stamm Michael , Hu Sheng wu 
Published: December 2011

ABSTRACTGenetic diversity information will be very valuable for future rapeseed (Brassica napus L.) improvement. The genetic diversity and relationships among 92 rapeseed accessions, including 44 from China, 22 from Europe, 16 from the United States, and 10 from Canada, were assessed by 60 random amplified polymorphic DNA (RAPD) and 22 expressed sequence tag (EST)‐simple sequence repeat (SSR) primers. In total, 618 RAPD and 117 EST‐SSR polymorphic fragments were detected. The average number of polymorphic fragments found by each RAPD primer was 10.3 ranging from 3 to 17 and that detected by each pair of EST‐SSR primer was 5.3 ranging from 4 to 7. The unweighted pair‐group method with arithmetic mean (UPGMA) cluster analysis revealed that these 92 accessions could be classified into three major clusters. Cluster I consisted of accessions mainly from China, which belong to the semi‐winter type. Cluster II contained accessions from Europe and the United States, which belong to the winter type. Cluster III was a semi‐winter and spring type mixture group, which contained accessions mainly from China and Canada. The principal component analysis and population structure analysis revealed similar results to the cluster analysis. Analysis of molecular variance result based on four geographic groups indicated that genetic variation was 8.24% among populations of geographic regions and 91.76% within geographic regions. Rapeseed accessions from the United Stated have the greatest genetic distance from accessions of other geographic origins, especially those from China. United States rapeseed could be important germplasm resources for enriching the genetic background of Chinese rapeseed and vice versa.
Genetic Diversity and Structure of Pepper (Capsicum AnnuumL.) from Northwestern Mexico Analyzed by Microsatellite Markers
Authors: Pacheco‐Olvera Antonio , Hernández‐Verdugo Sergio , Rocha‐Ramírez Víctor , González‐Rodríguez Antonio , Oyama Ken 
Published: December 2011

ABSTRACTThe analysis of the variability and genetic structure of wild and landrace populations of pepper (Capsicum annuumL.) is important for the management and conservation of valuable genetic resources and to understand the consequences of domestication on the patterns of neutral genetic variation. For this purpose, 12 populations of wild peppers, 3 landrace populations and 7 hybrid populations from northwestern Mexico were studied using microsatellites. On average, 3.62 alleles per locus were detected in the wild relatives, 3.37 in the landraces, and 3.08 in the hybrids. According to the average values of expected heterozygosity (He), slightly greater genetic diversity was found among the wild relatives (He = 0.466) than in the hybrids (He = 0.440) or the landraces (He = 0.422). In terms of the average number of alleles per locus and the average expected heterozygosity, reductions of 8.18 and 10.25% were found in the genetic diversity of the landraces and hybrids, respectively, with respect to the wild populations. The genetic differentiation among the populations was the highest among hybrids (GST= 0.324), followed by landraces (0.309) and wild relatives (the lowest, at 0.208). Cluster analysis clearly demarcated the wild relatives and domesticated populations into different groups. The high levels of genetic diversity found amongC. annuumin northwestern Mexico suggest that the wild and landrace populations are a valuable resource that should be conserved.