bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation and Characterization of Cu2Zn(GexSn1-x)Se4 Thin-films from Sputtered Elemental Precursors
Authors: Jan Antony , Yee Yesheng , Clemens Bruce M.
Published: May 2014

Thin-film absorber layers for photovoltaics have attracted much attention for their potential for low cost per unit power generation, due both to reduced material consumption and to higher tolerance for defects such as grain boundaries. Cu2ZnGeSe4 (CZGSe) comprises one such material system which has a near-optimal direct band gap of 1.6 eV for absorption of the solar spectrum, and is made primarily from earth-abundant elements.

CZGSe metallic precursor films were sputtered from Cu, Zn, and Ge onto Mo-coated soda lime glass substrates. These were then selenized in a two-zone close-space sublimation furnace using elemental Se as the source, with temperatures in the range of 400 to 500 C, and at a variety of background pressures. Films approximately 1-1.5 µm thick were obtained with the expected stannite crystal structure.

Next, Cu2ZnSnSe4 (CZTSe), which has a direct band gap of 1.0 eV, was prepared in a similar manner and combined with CZGSe as either compositionally homogeneous or layered absorbers. The compositional uniformity of selenide absorbers made by selenizing compositionally homogeneous Cu-Zn-Ge-Sn precursor layers was determined and the band gap as a function of composition was investigated in order to demonstrate that the band gap is tuneable for a range of compositions. For layered Cu-Zn-Ge/Cu-Zn-Sn precursor films, the composition profile was measured before and after selenization to assess the stability of the layered structure, and its applicability for forming a band-gap-graded device for improved current collection.
Spin fluctuations, Fermi surface hotspots and nesting in PuCoGa5
Authors: Graf Matthias J. , Das Tanmoy , Zhu Jian-Xin
Published: May 2014

Surprisingly little is known about the mechanism and symmetry of superconducting pairing in PuCoGa5. A common thread with other unconventional superconductors is the presence of spin fluctuations in the normal state, which in this particular case is controlled by strong spin–orbit coupling split bands. The many and anisotropic Fermi surfaces make the guessing of the potential spin-fluctuation nesting vector and resulting symmetry of the pairing function a nontrivial task. To provide much needed guidance for the identification of the pairing symmetry in this multiband superconductor, we perform first-principles based magnetic spin susceptibility calculations to identify the dominant nesting vectors that potentially give rise to interband pairing with nodal d- or s±-wave gap functions.
Theoretical confirmation of Ga-stabilized anti-ferromagnetism in plutonium metal
Authors: Söderlind Per , Landa Alex
Published: May 2014

The density-functional-theory model for plutonium metal is shown to be consistent with recent magnetic measurements that suggest anti-ferromagnetism in Pu-Ga alloys at low temperatures. The theoretical model predicts a stabilization of the face-centered-cubic (fcc, δ) form of plutonium in an anti-ferromagnetic configuration when alloyed with gallium. The ordered magnetic phase occurs because Ga removes the mechanical instability that exists for unalloyed δ-Pu. The cause of the Ga-induced stabilization is a combination of a lowering of the band (kinetic) and electrostatic (Coulomb) energies for the cubic relative to the tetragonal phase.
Polybenzimidazoles with Pendant Quaternary Ammonium Groups as Anion Exchange Membranes: Synthesis, Characterization and Alkaline Stability
Authors: Kulkarni Mahesh P. , Peckham Timothy J. , Thomas Owen D. , Holdcroft Steven
Published: May 2014

A novel method for introducing quaternary ammonium-bearing side chains has been developed and applied to a polybenzimidazole backbone to generate new anionic-exchange polymers, TMHA-m-FPBI where m = the degree of substitution of available sites (values ranging from 74 to 100%). These polymers have been shown to exhibit hydroxide ion conductivities up to 34 mS cm-1in hydrated membranes at ambient temperature and 13 mS cm-1at 60 °C, RH = 95%. Immersion of these polymers in 2 M KOH at 60 °C has shown they remain stable with no sign of chemical structure degradation to a period of at least 15 days.
Gordon Syndrome: Literature Review and a Report of Two Cases
Authors: Botha Sarel J.P. , Kloppers Hendrik P. , Bütow Kurt-W
Published: May 2014

The aim of this article is to publish a literature review and report on two new cases of Gordon syndrome (GS), a rare syndrome documented to have an autosomal dominant inheritance pattern or to occur sporadically; it is characterized by camptodactyly, cleft palate, and talipes equinovarus. We report two exceptional cases of GS where both patients were also diagnosed with congenital myopathy, and one developed malignant hyperthermia. These are the first two cases reported where patients were diagnosed with both GS and congenital myopathy or where GS is associated with malignant hyperthermia.
Mandibular Asymmetry in Patients with the Crouzon or Apert Syndrome
Authors: Elmi P. , Reitsma J.H. , Buschang P.H. , Wolvius E.B. , Ongkosuwito E.M.
Published: May 2014

The aim of this study was to describe directional and fluctuating mandibular asymmetry over time in children with Crouzon or Apert syndrome. Mandibular asymmetry of children between 7.5 and 14 years of age with Crouzon syndrome (n = 35) and Apert syndrome (n = 24) were compared with controls (n = 327). From panoramic radiographs, mandibular directional and fluctuating asymmetry was determined for the three groups. Multilevel statistical techniques were used to describe mandibular asymmetry changes over time. Patients with Crouzon and Apert syndromes showed statistically significant more fluctuating asymmetry for mandibular measures than did controls. Between the Crouzon and Apert syndromes groups, no statistical differences were found in directional and fluctuating asymmetry. The control group showed statistically significantly more directional asymmetry than did patients with Crouzon or Apert syndrome. The controls showed no change over time for the directional asymmetry of condylar-ramal height; however, the directional asymmetry of the gonial angle increased. Patients with Crouzon syndrome showed side dominance for only condylar-ramal height; whereas, patients with Apert syndrome did not show dominance for any of the measurements. Apert and Crouzon syndromes showed developmental instability, in contrast to the controls. No statistically significant longitudinal differences were found for either the directional or the fluctuating asymmetry between Crouzon and Apert syndromes. Findings for fluctuating and directional asymmetry for both syndromes may indicate an inability to cope with genetic and environmental stress during development and treatment, compared with untreated nonsyndromic individuals.
The Effectiveness of Psychosocial Intervention for Individuals with Cleft Lip and/or Palate
Authors: Norman Alyson , Persson Martin , Stock Nicola , Rumsey Nichola , Sandy Jonathan , Waylen Andrea , Edwards Zoe , Hammond Vanessa , Partridge Lucy , Ness Andy
Published: May 2014

Objective

The aim of this review was to assess the effectiveness of different psychological interventions for children and adults with cleft lip and/or palate and their parents.

Design

We searched six databases including MEDLINE and EMBASE to June 2013 and checked bibliographies. We included research that evaluated any psychological intervention in studies in which at least 90% of the participants had cleft lip and/or palate or were parents of those with cleft lip and/or palate. Studies containing less than 90% were excluded unless they reported results separately for those with cleft lip and/or palate, or raw data were available upon request from the authors. Inclusion assessment, data extraction, and risk of bias assessment were carried out independently by two reviewers.

Results

Seven studies were identified as inclusions, with only two studies being included in the full data analysis (one of which failed to meet the full inclusion criteria). The five remaining studies were included only in a narrative synthesis because data were available for people or parents of those with cleft lip and/or palate only. This highlights a distinct dearth of research into psychological intervention within the field of cleft lip and/or palate.

Conclusions

The review found no evidence to support any specific intervention. Key uncertainties need to be identified and addressed. Adequately powered, methodologically rigorous randomized controlled trials are needed to provide a secure evidence base for psychological intervention techniques in participants with cleft lip and/or palate and their parents.
Academic Outcomes of Children with Isolated Orofacial Clefts Compared with Children without a Major Birth Defect
Authors: Knight Jessica , Cassell Cynthia H. , Meyer Robert E. , Strauss Ronald P.
Published: May 2014

Objective

To compare academic outcomes between children with orofacial cleft (OFC) and children without major birth defects.

Design and Setting

In 2007–2008, we mailed questionnaires to a random sample of mothers of school-aged children with OFC and mothers of children without major birth defects (comparison group). The questionnaire included Likert-scale, closed-ended, and open-ended questions from validated instruments. We conducted bivariate and multivariable analyses on parent-reported educational outcomes and bivariate analyses on parent-reported presence of related medical conditions between children with isolated OFC and unaffected children.

Patients/Participants

A random sample of 504 parents of children with OFCs born 1996–2002 (age 5–12 years) were identified by the North Carolina Birth Defects Monitoring Program. A random sample of 504 parents of children without birth defects born 1996–2002 was selected from North Carolina birth certificates. Of the 289 (28.7%) respondents, we analyzed 112 children with isolated OFC and 138 unaffected children.

Main Outcome Measures

Letter grades, school days missed, and grade retention.

Results

Parents of children with isolated OFC reported more developmental disabilities and hearing and speech problems among their children than comparison parents. Children with isolated OFC were more likely to receive lower grades and miss more school days than unaffected children. Because of the low response rate, results should be interpreted cautiously.

Conclusion

Children with isolated OFC may have poorer academic outcomes during elementary school than their unaffected peers. Future studies are needed to confirm these results and determine whether these differences persist in later grades.
Farmland abandonment: threat or opportunity for biodiversity conservation? A global review
Authors: Queiroz Cibele , Beilin Ruth , Folke Carl , Lindborg Regina
Published: May 2014

Farmland abandonment is changing rural landscapes worldwide, but its impacts on biodiversity are still being debated in the scientific literature. While some researchers see it as a threat to biodiversity, others view it as an opportunity for habitat regeneration. We reviewed 276 published studies describing various effects of farmland abandonment on biodiversity and found that a study's geographic region, selected metrics, assessed taxa, and conservation focus significantly affected how those impacts were reported. Countries in Eurasia and the New World reported mainly negative and positive effects of farmland abandonment on biodiversity, respectively. Notably, contrasting impacts were recorded in different agricultural regions of the world that were otherwise similar in land‐use and biodiversity characteristics. We showed that the conservation focus (pre‐ or post‐abandonment) in different regions is an important factor influencing how scientists address the abandonment issue, and this may affect how land‐use policies are defined in agricultural landscapes.
Variation in vegetation and microbial linkages with slope aspect in a montane temperate hardwood forest
Authors: Gilliam Frank S. , Hédl Radim , Chudomelová Markéta , McCulley Rebecca L. , Nelson Jim A.
Published: May 2014

Plant ecologists have long been interested in aspect‐related contrasts of montane forests. Few studies have assessed correlation (linkage) among vegetation strata; fewer have included soil microbial communities. This study assessed contrasts in overstory, spring herbaceous, and soil microbial communities between northeast (NE) ‐ and southwest (SW) ‐facing slopes in a second‐growth West Virginia hardwood forest. We addressed three questions: (1) how do soil microbial, herbaceous layer, and overstory communities vary with slope aspect? (2) do forest vegetation strata and soil microbial communities exhibit linkage? (3) do biotic relationships and linkage vary with slope aspect? Moisture, organic matter, pH, soil NO3−, and net nitrification were significantly higher in NE soils; soil NH4+was significantly higher in SW soils, and net N mineralization was virtually identical between aspects. Vegetation communities markedly differed between the slopes. Overall, 29 tree and 118 herbaceous species were encountered, with overstory dominated by sugar maple and sweet buckeye on NE slopes and white oak on SW slopes. The herb layer of the NE aspect was characterized by forbs with fewer graminoids, whereas higher diversity and importance of graminoids were typical for SW slopes. Important microbial groups for NE soils were Gram‐positive and Gram‐negative bacteria; SW soils were dominated by fungal groups and Gram‐negative bacteria associated with environmental stress. Linkage was detected between soil microbes and overstory on the NE slope and between soil microbes and herb layer on the SW slope. We suggest that higher net radiation to the SW slope has created more weathered soil conditions, selecting for microbial groups both adapted to, and maintaining, low N availability (bottom‐up control). This has resulted in dominance of NO3−in less weathered NE soils and NH4+in more weathered SW soils. Other differences arose from contrasts in humus formation, driven by overstory species composition and maintained by soil moisture (top‐down control). Higher moisture of NE soils is more conducive to humus formation, supporting different microbial communities than the SW slopes with drier and often exposed mineral soil. Thus, plants and microbes can form biotic linkages in forest ecosystems which can vary among vegetation strata and with slope aspect.
Estimation of Bone Loss Biomarkers as a Diagnostic Tool for Peri‐Implantitis
Authors: Rakic Mia , Struillou Xavier , Petkovic‐Curcin Aleksandra , Matic Smiljana , Canullo Luigi , Sanz Mariano , Vojvodic Danilo
Published: May 2014

Background: The aims of this study are to estimate the profile of bone loss biomarkers in peri‐implant tissues and to identify potential prognostic biomarkers of peri‐implantitis.

Methods: Peri‐implant crevicular fluid samples collected from 164 participants (52 patients with peri‐implantitis, 54 with mucositis, and 58 with healthy peri‐implant tissues) were analyzed using enzyme‐linked immunosorbent assays to evaluate concentrations of the receptor activator of nuclear factor‐κB (RANK), soluble RANK ligand (sRANKL), osteoprotegerin (OPG), cathepsin‐K, and sclerostin.

Results: Concentrations of RANK, sRANKL, OPG, and sclerostin were significantly increased in patients with peri‐implantitis compared with patients with healthy peri‐implant tissues. Comparisons between peri‐implantitis and mucositis demonstrated significantly higher values of sclerostin in peri‐implantitis samples. Comparisons between mucositis and healthy peri‐implant tissues showed significantly increased levels of RANK and cathepsin‐K in mucositis.

Conclusion: These results are suggestive of a role of sRANKL, OPG, and sclerostin as prognostic biomarkers in peri‐implantitis.
Dual Use Switchgrass: Managing Switchgrass for Biomass Production and Summer Forage
Authors: Richner J. M. , Kallenbach R. L. , Roberts C. A.
Published: May 2014

The primary objective was to determine the feasibility of harvesting switchgrass (Panicum virgatum L.) for biomass and/or forage in a single season. Plots were located at Mt. Vernon, on Viraton silt loam (fine‐loamy, siliceous, active, mesic Oxyaquic Fragiudalf), and Columbia, on Mexico silt loam (fine, smectitic, mesic Vertic Epiaqualf), both in Missouri. Forage/biomass yields and nutritive value of samples intended for forage use, were compared between four harvest management treatments: a single post‐frost harvest for biomass (Treatment I), a forage harvest at boot stage followed by a post‐frost biomass harvest (Treatment II), biomass harvest at postanthesis with late summer regrowth harvested as forage (Treatment III) and biomass harvest at preanthesis with late summer regrowth harvested as forage (Treatment IV). A complementary study was conducted to determine the effects of switchgrass maturity stage on efficiency of conversion to glucose through enzymatic hydrolysis. Both studies were conducted in 2010 and 2011. The single, post‐frost harvest (Treatment I) yielded as much as or more biomass than any other treatment. At Mt. Vernon in both years, yields intended for forage use were greatest for Treatment II. At Columbia, forage yields were greatest for Treatment IV in 2010 while there was no difference between treatments in 2011. When forage harvests were compared, summer regrowth was generally more lignified than growth harvested at boot stage. Two‐harvest systems can yield as much as single harvest systems; producers should weigh the economic value of forage vs. biomass before deciding which strategy fits best.
Factors Affecting Manure Applications as Directed by Nutrient Management Plans at Four Connecticut Dairy Farms
Authors: Tao Haiying , Morris Thomas F. , Bravo-Ureta Boris E. , Meinert Richard
Published: May 2014

Distribution of manure on a farm is constrained by strategic, tactical, and operational factors and can be optimized by use of a nutrient management plan (NMP). Variables affecting a farmer's choice to implement manure recommendations can be identified by econometric models. Probit and feasible generalized least squares multiple regression models for panel data were fitted using 4 to 5 yr of field‐by‐field records of manure applications from four dairy farms in Connecticut. The results of the models showed that the farmers’ decisions about manure applications were significantly affected by a common factor: the distance from the manure storage lagoon to the field. Other factors, including field ownership, field size, crop, soil test P, recommended manure application, fertilizer N and P applications, and N and P requirements for crop growth, also significantly affected some of the farmers’ decisions about manure distribution. Identification of the factors affecting a farmer's decision is important for NMP planners and policymakers for developing more feasible and adoptable NMPs while minimizing the negative effects of land application of manure. This research illustrates how to use and interpret econometric models to analyze the decisions farmers make when they face two alternatives: a traditional practice or an improved NMP.
Sugarcane Yield Response to Nitrogen on Sand Soils
Authors: McCray J. Mabry , Morgan Kelly T. , Baucum Les , Ji Shangning
Published: May 2014

Maintenance of sufficient crop N for optimum sugarcane (Saccharum spp.) production on Florida mineral soils is critical but difficult because of high rainfall and the leachable nature of the sand soils. This study was conducted to determine sugarcane yield response to N on mineral soils in southern Florida and to revise current N recommendations. Four test sites were established on mineral soils (one Entisol, two Spodosols, and one Alfisol) with organic matter content of 7.2 to 16.9 g kg−1. Annual soluble N rates of 157, 202, 246, 291, and 336 kg N ha−1 were applied at Sites 1 to 3 and 0, 67, 134, 202, and 269 kg N ha−1 were applied at Site 4. Comparisons of four vs. five split N applications were made in some cases and three vs. four in other cases. Exponential models for plant and ratoon crops predicted 95% of maximum relative sucrose yield at 240 and 220 kg N ha−1, respectively, demonstrating yield response to rates higher than the current recommendation of 202 kg N ha−1. There were no yield differences between four and five split N applications for plant or ratoon crops, but one of two ratoon crops had increased sugarcane yield with four applications compared to three. Proposed N recommendations for plant and ratoon crops are 202 to 252 kg N ha−1 in four to five split applications and 172 to 222 kg N ha−1 in three to four split applications, respectively.
Genetic Relationships between Plant Height and Its Components in Japonica Rice
Authors: Wang Jingguo , Zou Detang , Zheng Hongliang , Zhao Hongwei , Liu Hualong , Jiang Tingbo
Published: May 2014

Plant height (PH) has strong genetic associations with plant height components (PHC), such as spike length (SL), the first (FIL), second (SIL), third (TIL) and fourth internode length (FOIL) from the top. To dissect the genetic relationships between PH and individual PHC, both unconditional (UAM) and conditional association mapping (CAM) were conducted by phenotyping 278 japonica rice (Oryza sativa L. subsp. japonica) accessions with 154 polymorphic SSR markers in 2010 and 2011. A total of 26 significant marker‐trait associations (MTAs) (P < 0.001) for PH were identified by using UAM within 19 markers in both years. Seven of the 19 markers were associated with PH in both 2010 and 2011. By using CAM, additional 35 significant MTAs (P < 0.001) were identified within 27 markers in 2 yr, when the influences of SL, FIL, SIL, TIL and FOIL were excluded. Four of the 27 markers were suppressed by different components in both years. CAM indicated that TIL contributed the most to PH, followed by SL, FOIL, SIL, and FIL. Any associated marker for PH identified by UAM and CAM was associated with at least one of the five PHC traits and explained 2.76 ∼ 15.20% of the phenotypic variation. The CAM could be used to evaluate genetic relationships between PH and PHC, and efficiently and precisely reveal counteracting associated markers. This study will provide theoretical bases for the improvement of PH in rice breeding programs.
Nutrient Source and Tillage Impacts on Tall Fescue Production and Soil Properties
Authors: Netthisinghe Annesly M. P. , Woosley Paul B. , Gilfillen Becky , Cook Kimberly L. , Sistani Karamat R.
Published: May 2014

Tall fescue [Schedonorus arundinaceus (Schreb.) Dumort.] provides a major forage base for livestock production in the southeastern United States. Forage production using manure helps recycle nutrients with fewer environmental impacts. This study examined tall fescue forage production and soil chemical properties when using broiler litter (BL), dairy manure (DMN), commercial fertilizer (CF), and a control (UTC) treatment in no‐till (NT) and conventional tillage (CT) systems. Forage nutritive values and majority of soil properties were not different in DMN, BL, and CF treatments. Herbage harvested was similar in BL and CF (9.3 and 8.1 Mg ha−1); DMN and UTC (6.6 and 5.6 Mg ha−1). Forage nutritive values in DMN and UTC were similar. Greater forage Cu and Zn contents were observed in BL and CF when compared to DMN and UTC. The soil pH of DMN treatment was 0.3 to 0.4 units higher than BL and CF. Soil organic matter (SOM) levels in all fertilizer treatments were similar (30.0–32.0 g kg−1). Broiler litter addition increased soil test P by 87%, NO3–N by 33%, and Cu by 30%, and Zn by 76%. The soil properties in DMN treatment did not change significantly. Tillage did not impact soil properties except for Fe; NDF (2012), Cu (2011), and Zn (2011). The results indicated that both broiler litter and dairy manure application can produce just as much herbage mass as commercial fertilizers with similar nutritive value. When manure is applied to meet crop N requirement, BL caused more intense soil nutrient loading than DMN.
Row Arrangement, Phosphorus Fertility, and Hybrid Contributions to Managing Increased Plant Density of Maize
Authors: Haegele Jason W. , Becker Ryan J. , Henninger Adam S. , Below Frederick E.
Published: May 2014

Inter‐plant competition must be carefully managed to realize the yield potential of increased plant density of maize (Zea mays L.). Twin row planting arrangement, P fertility, and hybrid selection may be important components of managing increased plant density. Our hypotheses were (i) that twin row planting arrangement would be superior to traditional 0.76‐m rows at ultra‐high densities and (ii) that supplemental P fertility would alleviate inter‐plant competition. In 2010 and 2011, twin row planting arrangement was compared to single 0.76‐m rows across densities ranging from 61,775 to 160,615 plants ha−1 and P fertility treatments ranging from 0 to 168 kg P2O5 ha−1. Twin rows did not increase yield relative to single rows, and twin rows often yielded significantly less at plant densities greater than 111,195 plants ha−1. Mean responses to supplemental fertility were 1.0 and 0.3 Mg ha−1 in 2010 and 2011, respectively. There was no interaction between plant density and P fertility suggesting that extra resource availability does not necessarily overcome inter‐plant competition. In 2011, two hybrids of contrasting ear type were included to explore the role of hybrid selection in plant density response. Maximum yields of each hybrid were achieved at contrasting densities, and genetic differences in plant density tolerance appeared to be related to (i) kernel number response on a per‐area basis and (ii) stability of individual kernel weight. These results highlight the importance of independently optimizing row spacing and soil fertility while understanding the plant density response characteristics of maize hybrids.
Diurnal Variability in Reflectance Measurements from Cotton
Authors: Oliveira Luciane F. , Scharf Peter C.
Published: May 2014

Diurnal variability of reflectance measurements on crop plants has been documented for passive sensors, but minimally studied for active sensors. Active sensors are now commercially available for crop management decisions including diagnosis and control of N rate. Our objective was to quantify variability during the day for both passive and active sensors mounted above a cotton canopy, and to assess the effect that this variability would have on N rate decisions. Measurements were taken from 0600 to 2000 h at early square, midsquare, and early flower growth stages using Cropscan (passive), Crop Circle (active), and GreenSeeker (active) reflectance sensors. Average CV for GreenSeeker was higher than for Crop Circle for visible/near‐infrared (Vis/NIR) (P = 0.01) and possibly for normalized difference vegetative index (NDVI) as well (P = 0.15). Variability in Cropscan reflectance was much higher in north‐south than in east‐west rows. When restricted to east‐west rows, Cropscan CVs were equal to or lower than the other sensors. Nitrogen rates calculated from sensor measurements also were more variable for GreenSeeker (SD ≥ 19 kg N ha–1) than for Crop Circle (SD ≥ 12 kg N ha–1) (P < 0.09). GreenSeeker NDVI followed a consistent diurnal pattern: lower in midday and higher in morning and evening. A regression equation using temperature, solar radiation, and solar time explained 45 to 50% of this variability, and could potentially be used to correct values during field use. Additional study to isolate causal factors of variability is justified. Strategies to compensate for drift in reflectance measurements will be needed when using sensors to control applications of N fertilizer or other inputs, even for active sensors.
Genomic Selection for the Traits Expressed after Pollination in Allogamous Plants
Authors: Yabe Shiori , Ohsawa Ryo , Iwata Hiroyoshi
Published: May 2014

Mass selection, a breeding method commonly used to improve allogamous crops, is characterized by low efficiency, especially when a target trait is expressed after pollination. The trait cannot be observed before pollination. Therefore, pollen from unselected plants contributes to the next generation. Genomic selection (GS) enables prediction of the genetic potential of plants from marker genotypes and selection of good pollen parents before pollination. This study investigated the potential of GS in mass selection of a trait expressed after pollination via breeding simulations with annual allogamous plants. We compared GS and phenotypic selection (PS) in traits expressed before and after pollination. Genetic gain attained by PS breeding was much lower than the gain by GS breeding in a trait expressed after pollination. Genetic gain attained by GS breeding was almost equal between traits expressed before pollination and after, except when the breeding cycle was once per year. High efficiency of GS breeding in a trait expressed after pollination was attributable to the high selection accuracy of chromosomes derived from a pollen parent at GS immediately after selection with model update, where we did not select pollen parents because of phenotype requirements. It engendered increased population size and prevented depletion of genetic variation in a breeding population. Results show that GS is effective for improvement of a trait expressed after pollination.
Time and Temperature Interactions in Freezing Tolerance of Winter Wheat
Authors: Skinner D. Z.
Published: May 2014

To survive the temperature fluctuations that occur during the winter months, winter wheat (Triticum aestivum L.) plants must tolerate episodes of freezing of varying intensity and duration. In this study, the ability of six wheat cultivars to survive exposure to −13.5 to −16.5°C for 2, 3, or 4 h was measured. Tolerance was described as the percentages of plants surviving after time intervals at −10°C or less. The average survival of the six cultivars significantly decreased by about 50% as length of exposure to −10°C or less was increased from 325 to 525 min. Surprisingly, survival then increased with longer exposure times such that the percentages of plants surviving were similar after 675, and after 325 min at −10°C or less. The greater survival after longer exposure times to −10°C or less compared with shorter exposure times suggested that certain freezing tolerance mechanism(s) in wheat are activated only after sufficient exposure to subfreezing temperatures for a sufficient amount of time. Lesser exposure to either temperature or time apparently does not activate this mechanism, leading to greater plant death. Further characterization of this mechanism and its genetic control may lead to development of wheat lines with enhanced ability to survive harsh freezing conditions and thus improved winterhardiness.
Next Generation Transcriptomic Sequencing and Polymorphism Detection in Pepper Varieties Saengryeg 211 and Saengryeg 213
Authors: Ahn Yul‐Kyun , Tripathi Swati , Cho Young‐Il , Kim Jeong‐Ho , Lee Hye‐Eun , Kim Do‐Sun , Woo Jong‐Gyu , Yoon Moo‐Kyoung
Published: May 2014

Limited functional genomics resources and whole genome association studies could be substantially improved in pepper (Capsicum annuumL., Solanaceae) through the application of a molecular approach for characterization of gene content and identification of molecular markers. We performed 454 GS‐FLX Titanium massive parallel pyrosequencing of polyA‐selected and normalized cDNA libraries generated from a single pool of transcripts obtained from two pepper varieties, the highly pungent Saengryeg 211 and the nonpungent Saengryeg 213, for de novo transcriptome assembly, functional annotation, and in silico discovery of potential molecular markers. A single 454 pyrosequencing run generated 361,671 and 274,269 reads totaling 164.49 and 124.60 Mb of sequence data, which assembled into 23,821 and 17,813 isotigs and 18,147 and 15,129 singletons for both varieties, respectively. These reads were organized into 20,352 and 15,781 ‘isogroups’ for both varieties. Assembled sequences were functionally annotated on the basis of homology to genes in multiple public databases and assigned with gene ontology (GO) terms. Analysis of sequence variants identified a total of 11,584 and 9641 potential single nucleotide polymorphisms (SNPs), which eventually resulted in 665 and 632 genotype‐specific SNPs for both the varieties, respectively, after examining SNP frequency distribution for each mapped unigenes. High‐throughput transcriptome profiling and large scale of polymorphic marker discovery using next generation sequencing (NGS) of two pepper varieties provides valuable information for functional genomics resources, which will help to further improve the pepper‐breeding efforts with respect to genetic linkage maps, quantitative trait locus (QTL) mapping, and marker‐assisted trait selection.
Physiological and Biochemical Effects of Ultra‐Dry Storage on Barbados Nut Seeds
Authors: Cui Kai , Wang Haiying , Li Kun , Liao Shengxi , Li Li , Zhang Chunhua
Published: May 2014

In this study, the feasibility of ultra‐dry storage of Barbados nut (Jatropha curcas L.) seeds was investigated. The J. curcas seeds were dehydrated to six different moisture contents (1.33–6.98%) and stored at ambient temperature for 3 yr. Then, the indices related to seed vigor were measured. To explore the mechanism of ultra‐dry storage, some physiological and biochemical indicators, including electrical conductivity (EC); contents of proline (Pro) and malondialdehyde (MDA); activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR); total soluble sugar content; and fatty acid composition, were determined. Results indicated that moisture content and prehumidification method significantly affected seed germination and vigor. The ultra‐dried seeds showed a higher germination percentage than nondehydrated seeds. The germination percentage of ultra‐dried seeds was negatively correlated with EC and MDA content and positively correlated with the activities of five antioxidant enzymes. As compared with the nondehydrated seeds, the ultra‐dried seeds had lower soluble sugar and higher unsaturated fatty acids contents. The moisture content of 4.06% was found to be the optimal ultra‐drying treatment, which is beneficial to enhance the activity of antioxidant enzymes and reduce lipid peroxidation of cell membranes, thereby slowing the decline in viability of J. curcas seeds.
Mapping of QTL for Tolerance to Cereal Yellow Dwarf Virus in Two‐rowed Spring Barley
Authors: del Blanco Isabel A. , Hegarty Joshua , Gallagher L. W. , Falk B. W. , Brown‐Guedira G. , Pellerin E. , Dubcovsky J.
Published: May 2014

Cereal yellow dwarf virus (CYDV‐RPV) causes a serious viral disease affecting small grain crops around the world. In the United States, it frequently is present in California where it causes significant yield losses, and when infections start early in development, plant death. CYDV is transmitted by aphids, and it has been a major impediment to developing malting barley in California. To identify chromosome locations associated with tolerance/resistance to CYDV, a segregating population of 184 recombinant inbred lines (RIL) from a cross of the California‐adapted malting barley line Butta 12 with the CYDV‐tolerant Madre Selva was used to construct a genetic map including 180 polymorphic markers mapping to 170 unique loci. Tolerance to CYDV was evaluated in replicated experiments where plants were challenged by aphid mediated inoculation with the isolate CYDV‐RPV in a controlled environment. Quantitative trait loci (QTL) analysis revealed the presence of two major QTL for CYDV tolerance from Madre Selva on chromosomes 2H (Qcyd.MaBu‐1) and 7H (Qcyd.MaBu‐2), and 4 minor QTL from Butta 12 on chromosomes 3H, 4H, and 2H. This paper discusses the contribution of each QTL and its potential value to improve barley tolerance to CYDV.
Selfing and Outcrossing Fertility in Common Bermudagrass under Open‐Pollinating Conditions Examined by SSR Markers
Authors: Tan Chengcheng , Wu Yanqi , Taliaferro Charles M. , Bell Greg E. , Martin Dennis L. , Smith Mike W. , Moss Justin Q.
Published: May 2014

C. dactylon (L.) Pers. var. dactylon is a cosmopolitan grass species with significant economic value for turf, forage, and soil conservation in the southern United States. The species has long been characterized as an outcrossing species based on heterogeneity of natural populations, comparison of seed set rates under self‐ and cross‐pollination, and assumption of widespread self‐incompatibility. However, reproductive behavior of plants in breeding populations based on definitive characterization of their progeny as to self‐ or cross‐pollinated origin is not available. The objective of this experiment was to quantify selfing and outcrossing rates of common bermudagrass plants grown in field environments conducive to interbreeding. Twenty‐five clonal common bermudagrass plants grown at Stillwater and Perkins, OK in a randomized complete block design with three replications were used in the study. Ten progeny from open‐pollinated seed harvested from each field plot of the maternal plants were grown in a greenhouse at the Agronomy Research Station, Oklahoma State University. Plant DNA samples were isolated from 1439 progeny from both sites along with the 25 seed parents. Eleven polymorphic simple sequence repeat (SSR) markers were chosen to identify breeding origin of the progeny by comparing SSR marker genotypes of the progeny with their respective maternal parents. Among the progeny examined, only two progeny plants from accessions A12281 and A12363 were identified to be selfed, indicating an extremely high outcrossing rate of 99.86%. The finding of complete or near complete outcrossing behavior in this experiment should assist in a fuller understanding of the sexual reproduction characteristics of common bermudagrass.
A Three‐Dimensional View of Nutrient Hotspots in a Sierra Nevada Forest Soil
Authors: Johnson D.W. , Woodward C. , Meadows M.W.
Published: May 2014

Soil nutrient hotspots have important influences on both plant nutrition and water quality that are obscured by averaging values and eliminating outliers from data sets. An investigation of soil nutrient hotspots and hot moments was conducted in a Sierra Nevada forest soil using a matrix of resin capsules placed at various depths and collected at two times (first precipitation in autumn, Mediterranean climate, and post‐snowmelt in spring). Fluxes of Ca2+ and Mg2+ in the mineral soil were much greater in the spring than in the autumn samples, suggesting that soil water flux was a major factor. The reverse was true for NH4+ and Na+, for which most total fluxes occurred during the first precipitation in autumn. Fluxes of NH4+, NO3−, and ortho‐P declined with depth in most cases, whereas the patterns in average fluxes of Na+, Ca2+, and Mg2+ with depth were inconsistent. More than 85% of hotspots for NH4+, NO3−, ortho‐P, Na+, and Ca2+ were also hot moments (varied spatially with time). Most hotspots for Mg2+ were spatially co‐located with time (fewer hot moments), perhaps indicating local variations in soil Mg or preferential flow paths. Hotspots were more common for NH4+ and NO3− than for Ca2+, as noted in most previous studies at this site. Whether the latter reflects fundamental differences between C and N or the relative abundance of these ions in the soil remains to be determined.
Evaluating the Role of Point Source Discharges Informs Statewide Nutrient Control Policy in Utah
Authors: Daigger Glen T. , Datta Tania , Stensel H. David , Whitlock Drury D. , Mackey John K.
Published: May 2014

An evaluation of costs, rate, and environmental impacts of upgrading publically owned treatment works (POTWs) in the State of Utah to four levels of nutrient control allowed a variety of nutrient control policies to be assessed. Upgrade costs and rate impacts indicated that costs would be within a defined range for many POTWs, especially with design capacities greater than 40,000 m3/day (∼10 mgd). However, costs were significantly higher for some POTWs with lower design capacities, and nutrient upgrades to the most stringent levels would not be affordable for these communities, representing about 15 percent of the service population. The resulting equity issues can be addressed through hardship grants program and/or regulations based on a trading scheme. Analysis demonstrated that trading offers advantages, including cost efficiency and flexibility to accommodate further nutrient reductions and population growth, and greater ability to interface with urban and rural nonpoint nutrient control. Currently, the State of Utah is establishing technology‐based nutrient limits that can be affordably implemented at all POTWs in phases. Additionally, a multi‐faceted approach is being evaluated that will consider prioritized watershed‐scale strategies, point and nonpoint sources of pollution, ecological and socioeconomic implications, and stakeholder participation in nutrient reduction programs.
Effect of Nutrients on Bioaccumulation of Heavy Metals in a Tropical Urban Coastal Lacustrine System
Authors: Sheela A. M. , Letha J. , Sabu Joseph , Jobin Thomas , Justus J.
Published: May 2014

The study on bioaccumulation of heavy metals in a lake reveals that during the nonrainy season, accumulation of cadmium in plankton is high in the upstream of the lake where anoxic freshwater condition exists resulting from inflow of urban wastes. Stern action is required to stop the bypass of sewage from the old sewer system especially in the commercial areas of Thiruvananthapuram city, either by augmenting the sewerage system or by treating sewage at the source. During monsoon season, the accumulation of heavy metals—namely lead and nickel, followed by cadmium and chromium—is high in phytoplankton resulting from high nitrate content caused by heavy rainfall. During postmonsoon, lead and nickel accumulation is high. The study emphasizes the need for stormwater management practices for the removal of lead in urban runoff from roads caused by vehicular exhaust, tire wear, and wastes from service stations and workshops.
Constructive Controversy as a Means of Teaching Citizens How to Engage in Political Discourse
Authors: Johnson David W. , Johnson Roger T.
Published: May 2014

Positive political discourse is the heart of democracy. The purposes of political discourse include making an effective decision about the course the society should take and building a moral bond among all members of the society. A responsibility of social sciences within a democratic society is to provide the theory, research, and normative procedures needed to make political discourse constructive. A theory underlying political discourse is constructive controversy. There is considerable research that indicates controversy results in significant increases in the quality and creativity of decision making and problem solving, the quality of relationships among citizens, and improvements in the psychological health of the citizenry. From the validated theory, both a teaching and decision making procedure has been developed and field tested. The theory of constructive controversy, the supporting research, and the normative procedure provide a valid empirically based process for political discourse.
Selective Critical Thinking: A Textbook Analysis of Education for Critical Thinking in Norwegian Social Studies
Authors: Børhaug Kjetil
Published: May 2014

Current Norwegian curricular guidelines oblige schools to educate citizens with a critical perspective on society. From a discourse theoretical perspective, this obligation implies that various school subjects, and in particular social studies, offer discourses on social issues that allow for different points of view and critical evaluation. Educational systems have a strong tendency towards legitimising the existing social and political order. It is therefore important to examine whether critical perspectives are articulated at all, and exactly what students are encouraged to criticise. Globalisation processes are assumed to affect the extent and form of critical assessment. In this article, the textbooks used in Norwegian lower secondary schools in social studies are examined. It is found that critical perspectives are articulated, but systematically directed at issues that do not challenge core political and legal institutions, such as economic policy, non-voters, non-democratic regimes far away, and racists. Political and legal institutions, the United Nations, and Norwegian multiculturalism are above any type of critical assessment. It can be concluded that critical assessments are encouraged, albeit being guided in some directions and not others.
Taking Relationships to School: Power, Authority and Identity Work in Young People's Dispositions to Schooling
Authors: Wadham Ben , Owens Larry , Skryzpiec Grace
Published: May 2014

The question of student engagement in schooling, or adherence to school values, is often conceived in terms of student transgression. Youth has, over time, become a problem to be solved – by parents, teachers and school administrators. This article outlines an engagement with lower socioeconomic status metropolitan schooling in South Australia, seeking to understand the clash of frames of reference between elements of the student body and the school adult population. Twenty-two semi-structured in-depth interviews with young people, and observations at the school, highlighted a strong theme of divergent intercultural relations, articulated in questions of power, authority and identity. The authors explore their relationships to authority as an expression of complex family and schooling relations, and the negotiation of conventional and marginalised cultures. The students' accounts describe troubled and unstable family relationships marked by violence, alcohol and drug use, and poverty and unemployment. The authors assert that the students bring their relationships to school, and that school could focus on the three principles of trust, confidence and respect as a means of improving student engagement. A focus on respectful relationships decentres adult constructions of the ‘problem’ and provides a collaborative and (re)conciliatory approach to improving school culture.
Effect of Rotation Speed on the Quality of Friction Welded AA 6061/AA 7075 Joints
Authors: Orhan Ayhan , Asma Yücel
Published: May 2014

In this experimental study, the alloys AA6061 and AA7075 which have different properties but common usage areas such as aviation, space, and defence industry are difficult and problematic to be welded by conventional fusion welding methods. However, friction welding represents a modern and alternative joining method. For such welded joints, rotation speed was used as variable parameter, and so joints with different mechanical and microstructural properties were obtained. The crosssectional microstructure of friction welds were examined by optical microscopy. In order to determine the mechanical properties, microhardness and tensile tests were performed on the welded samples. Fracture surfaces obtained as a result of tensile tests were examined by scanning electron microscopy (SEM) and fracture type as well as fracture surface characteristics were investigated.