bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diel Feeding Chronology, Gastric Evacuation, and Daily Food Consumption of Juvenile Chinook Salmon in Oregon Coastal Waters
Authors: Benkwitt Cassandra E. , Brodeur Richard D. , Hurst Thomas P. , Daly Elizabeth A. 
Published: January 2009

AbstractThe diel feeding periodicity of juvenile Chinook salmon Oncorhynchus tshawytscha was determined from stomachs collected in coastal waters off Oregon in 2000 and 2003. Juvenile Chinook salmon exhibited a diurnal feeding pattern with morning and evening feeding periods. There were differences in the duration and magnitude of the dawn and dusk peaks between the 2 years. Gastric evacuation rates of euphausiid meals were estimated from laboratory experiments at 9.3, 10.7, and 13.9°C. Based on an exponential model, the instantaneous evacuation rates at these three temperatures were 0.0407, 0.0589, and 0.0807 per hour, respectively. The daily ration of juvenile Chinook salmon in Oregon coastal waters in 2000 and 2003 was estimated using three models. Using laboratory‐derived evacuation rates, the Elliott and Persson and Eggers models produced daily ration estimates of 2.04% and 2.57% of body weight (BW), respectively, in 2000 and 2.93% and 2.46%BW in 2003. The MAXIMS model, which does not rely on laboratory‐derived evacuation rates, produced higher estimates of daily ration (3.84% and 4.28%BW). Our diel feeding chronology, gastric evacuation rate, and daily ration estimates for juvenile Chinook salmon were comparable to those of other juvenile salmonids.
Increased Population Density and Suppressed Prey Biomass: Relative Impacts on Juvenile Atlantic Salmon Growth
Authors: Ward D. M. , Nislow K. H. , Folt C. L. 
Published: January 2009

AbstractIndividual growth rates of fish often depend on both population density and resource availability, both of which are subject to anthropogenic impacts and can be manipulated in the interest of restoring or enhancing fish populations. However, direct tests of the relative contribution of these factors to growth variation are lacking for most populations and are critically needed to guide management. We used a large‐scale field experiment to evaluate the relative effects of increased population density and suppressed prey biomass on the growth of juvenile Atlantic salmon Salmo salar. We directly manipulated salmon population density by releasing newly hatched salmon fry from uniform initial conditions at three density treatments in natural streams (18 sites total, repeated over 2 years). We arrayed the density treatments across sites that encompassed a more than 10‐fold range in the biomass of benthic invertebrate prey for salmon, a low prey biomass being associated with heavy shading from riparian forest canopy. This controlled approach clearly demonstrated the enormous growth plasticity of juvenile Atlantic salmon; their mean body mass ranging from 1.2 to 14 g across sites after one growing season. Variation in prey biomass had the strongest effects on fish growth. The fish grew faster at sites with high prey biomass regardless of population density, and prey biomass alone accounted for 71% of the explained variation in their growth. Only after taking the variation explained by prey biomass into account was it apparent that the study fish grew faster at sites with low stocking density and at sites where high losses reduced Atlantic salmon population density. To maintain salmon growth and size‐dependent life histories, restoration and management efforts clearly need to consider anthropogenic factors that suppress prey abundance.
Missing in Action: Vocabulary Instruction in Pre‐K
Authors: Neuman Susan B. , Dwyer Julie 
Published: January 2009

Recognizing the importance of starting early, the purpose of our article is to examine if and how vocabulary is taught in commercially prepared early literacy curriculum for pre‐K. Ten curriculum programs are reviewed to determine the prevalence of vocabulary instruction and the pedagogical practices used to support the learning of words and their meanings. Results of the analysis indicate a paucity of instructional guidance in vocabulary in pre‐K early literacy curriculum programs.إن غرض مقالتنا هذه هو أن يستقصى إذا وكيف يتم تعليم المفردات في منهاج التعلم المبكر الذي قد حضر تجارياً لمرحلة التعليم ما قبل الروضة إدراكاً لأهمية الانطلاق المبكر. ولقد تمت المراجعة لعشرة برامج منهاجية كي يحدد انتشار تعليم المفردات والممارسات التعليمية المستخدمة لدعم اكتساب الكلمات ومعانيها. وتشير نتائج التحليل إلى قلة التوجيه التعليمي في المفردات في برامج التعلم المنهاجية ما قبل الروضة.本文作者意识到及早开始学习字汇的重要性。本文目的是考查由商营机构提供的幼儿前读写课程是否有教授字汇和怎样教授字汇。本文评审了十个课程，考查教授字汇的普遍性，以及为支持学习单字和单字的意思所采用的教学实践。分析结果显示，只有少数的幼儿前读写课程会给予学生在学习字汇方面的教学指引。Reconnaissant l'importance de commencer tôt, notre article a pour but d'examiner si et de quelle façon on enseigne le vocabulaire dans le matériel pédagogique du commerce destiné aux enfants d'avant le jardin d'enfants au début de la lecture‐écriture. On a examiné dix matériels afin de déterminer la prévalence de l'enseignement du vocabulaire et des pratiques pédagogiques employées en vue de l'apprentissage des mots et de leurs significations. Les résultats de l'analyse montrent un manque de guidage didactique en matière de vocabulaire dans les matériels destinés aux enfants d'avant le jardin d'enfants au début de la lecture‐écriture.Цель данной статьи: выяснить, предусмотрено ли расширение словарного запаса детей в рамках коммерчески разработанных программ для дошкольников и если да, то как именно это осуществляется. Признавая важность раннего обучения, авторы проанализировали десять учебных программ, чтобы определить, включают ли они в себя работу с лексикой и какими методами достигается усвоение слов и понимание их смысла. Результаты анализа указывают на недостаточность работы со словарем в учебных планах по развитию грамотности дошкольников.Concientes de la importancia de empezar temprano, el propósito de nuestro artículo es el de examinar si y cómo se enseña el vocabulario en los currículos preparados por el comercio para los grados pre‐K. Se examinaron diez programas para determinar cuán común era la instrucción de vocabulario y las prácticas pedagógicas usadas para apoyar el aprendizaje de las palabras y sus significados. Los resultados del análisis indican una falta de orientación en la instrucción de vocabulario en los programas curriculares de alfabetización en el pre‐K.
Bloat Reduction Potential of an Alfalfa Cultivar Selected for Low Initial Ruminal Disappearance
Authors: Bernáldez M. Laura , Basigalup Daniel H. , Ferrer Jorge Martínez , Balzarini Mónica , Alomar Daniel 
Published: January 2009

ABSTRACTFoamy bloat causes large economic losses in beef and dairy grazing systems based on alfalfa (Medicago sativa L.). Dry matter (DM) disappearance at initial stages of rumen fermentation is associated with bloat. The National Institute for Agricultural Technology, Argentina, developed a cultivar of alfalfa (Carmina) with low initial ruminal DM disappearance (LIRD). To study the bloat reduction potential of Carmina, a grazing trial using steers was conducted. The trial was repeated in 10 periods using the cultivar Barbara as control. Bloat frequency and severity were estimated by direct observation of each animal after the start of grazing. Just before grazing, forage samples were taken so as to characterize agronomic properties and chemical composition of the pasture. Cultivars were not different in crude protein, neutral detergent fiber, acid detergent fiber, and lignin concentration (248, 317, 239, and 58 g kg−1 DM, respectively). Overall, Carmina reduced bloat occurrence (P < 0.01) by 25.2% compared to Barbara, but presented a lower forage DM yield per hectare and a slight more advanced maturity stage (cultivars were grazed from early to mid‐bud). Selection for LIRD was an effective way to reduce bloat risk.
Gene Expression and Isoflavone Concentrations in Soybean Sprouts Treated with Chitosan
Authors: Chen Huilan , Seguin Philippe , Archambault Annie , Constan Lea , Jabaji Suha 
Published: January 2009

ABSTRACTThis study was undertaken to investigate whether chitosan treatments of sprouts of three soybean [Glycine max (L.) Merr.] cultivars (OAC Champion, AC Orford, and AC Proteina) can increase not only concentration of isoflavones in sprouts but also the transcript levels of genes and their subfamilies encoding enzymes at key points of the phenylpropanoid pathway (phenylalanine ammonia‐lyase [E.C. 4.3.1.5], chalcone synthase [E.C. 2.3.1.74], chalcone isomerase [E.C. 5.5.1.6], and chalcone reductase [E.C. 2.3.1.170]), and at a key branch‐point enzyme in isoflavone biosynthesis (isoflavone synthase [E.C. 1.14.13.86]). Chitosan effects on transcript levels of 14 genes differed depending on the cultivar as demonstrated by significant interactions (P < 0.05) between soybean cultivar and chitosan treatment for all genes. For all cultivars, response to chitosan treatments varied significantly depending on the gene. Overall, the greatest response was observed with high molecular weight chitosan. Very‐low‐ and low‐isoflavone cultivars (i.e., AC Orford and OAC Champion) sometimes responded positively to chitosan treatments, while the high‐isoflavone cultivar (i.e., AC Proteina) responded only negatively to chitosan. Chitosan treatments had limited effect on isoflavone concentrations, only reducing glycitein in OAC Champion by 38%. No correlation was found between gene expression and isoflavone concentrations. Differences in isoflavone concentrations were observed between sprouts of the three cultivars; AC Proteina had the highest isoflavone concentration and AC Orford the lowest. Results indicate that although isoflavone concentration and gene expression varied with cultivar, chitosan treatment is not a viable option for increasing isoflavone content in sprouts of cultivars evaluated.
Early Growth of Flint Maize Landraces under Cool Conditions
Authors: Peter Roland , Eschholz Tobias W. , Stamp Peter , Liedgens Markus 
Published: January 2009

ABSTRACTCold stress is a major factor that limits the success of environmentally sound cultivation of maize in central and northern Europe. This study evaluated the early growth of seven groups of Swiss Flint maize landraces (Zea mays L. ssp. mays) of different geographic origin under controlled cool conditions by assessing shoot and root traits. Measurements of plants, subjected to a permanent cold stress of 15/13°C (day/night), were made at the three‐leaf stage of the check Magister, a hybrid of approved good early vigor. The ranking (univariate analysis of variance) and the multivariate clustering of the groups of landraces differed when root and shoot traits were included in the evaluation. Furthermore, the association of phenotype with geographic parameters was successful only when root traits were considered. Groups of Swiss landrace accessions expressed three types of phenotypes under cold conditions: (i) large leaf area and an extensive axile root system for landraces from the Tessin and the Poschiavo valley (i.e., south of the Alps), (ii) large leaf area and a short axile root system in landraces from the Linth valley, the lower Rhine valley, and the posterior Rhine valley, all of which are north of the Alps, (iii) small leaf area and a short axile root system in landraces from the anterior Rhine valley and the Swiss Rhône valley. The method of root phenotyping (i.e., a simple and rapid determination of traits of axile roots) proved suitable for the characterization of a large number of samples, as is typically required in quantitative genetic analysis.
Novel Safflower Germplasm with Increased Saturated Fatty Acid Content
Authors: Hamdan Yamen A. S. , Pérez‐Vich Begoña , Fernández‐Martínez José M. , Velasco Leonardo 
Published: January 2009

ABSTRACTSafflower (Carthamus tinctorius L.) oil with high concentration of saturated fatty acids has potential applications in the food industry. So far only germplasm with increased stearic acid content (50–120 g kg−1), controlled by alleles at the locus St, has been developed. The objectives of the present research were to evaluate safflower germplasm for saturated fatty acid content, to isolate lines with increased levels of palmitic acid and stearic acid, to study the inheritance of both traits, and to evaluate the feasibility of recombining them. Germplasm evaluation and further selection led to the isolation of the line CR‐50 with increased palmitic acid content (98.2 ± 7.9 g kg−1 vs. 64.0 ± 3.4 g kg−1 in the check) and the line CR‐13 with increased stearic acid content (92.8 ± 9.2 g kg−1 vs. 22.2 ± 3.4 g kg−1 in the check). Inheritance studies including evaluation of F1, F2, and F3 seed generations from crosses with the nuclear male‐sterile line CL1, with conventional fatty acid profile, suggested that increased palmitic acid content was determined by additive alleles at a single locus Pa, whereas stearic acid content was controlled by partially recessive alleles at a single locus, probably St. Recombination of pa and st alleles produced transgressive segregants with 211.3 ± 14.6 g kg−1 saturated fatty acids, compared with 149.6 ± 14.0 g kg−1 in CR‐50, 159.7 ± 8.0 g kg−1 in CR‐13, and 89.3 ± 4.9 in the line CL1. These are the highest levels of saturated fatty acids reported so far in safflower.
Genetic Mapping of Sheath Blight Resistance QTLs within Tropical Japonica Rice Cultivars
Authors: Sharma Arun , McClung Anna M. , Pinson Shannon R. M. , Kepiro Joseph L. , Shank A. Robert , Tabien Rodante E. , Fjellstrom Robert 
Published: January 2009

ABSTRACTMost commercial cultivars of rice (Oryza sativa L.) are susceptible to sheath blight (SB), a devastating fungal disease causing significant losses in grain yield and quality. There are limited sources of genetic resistance adapted to U.S. growing conditions, and no commercial long grain cultivar of rice is currently available in the United States with a high level of SB resistance. Sheath blight resistance has been reported to be horizontal and quantitative. A population of 279 F2:3 progeny rows derived from a cross between two tropical japonica U.S. rice cultivars, Rosemont (semi‐dwarf, SB susceptible) and Pecos (tall, SB resistant), was used to map SB resistance. Progeny families were evaluated for disease reactions, plant height (PH), and heading date (HD) in replicated field trials for 2 yr and genotyped with 149 simple sequence repeat markers. Correlation analysis between SB ratings with PH and HD showed that both agronomic traits were significantly correlated with SB resistance. Four significant (logarithm of odds ratio ≥ 3.6) quantitative trait loci (QTLs) were identified for SB resistance, with individual effects explaining 5.6 to 33.4% of the total phenotypic variation. Plant height appears to have a direct influence on SB resistance, with QTLs for these traits colocated on chromosome 1. Consistent results across years indicate the stability of the identified QTLs and their potential for improving rice SB resistance using marker‐assisted selection.
Genome‐Wide Reduction of Genetic Diversity in Wheat Breeding
Authors: Fu Yong‐Bi , Somers Daryl J. 
Published: January 2009

ABSTRACTPublic concerns about crop uniformity introduced by modern plant breeding and genetic vulnerability to biotic and abiotic stresses have been one of the major forces driving long‐term efforts in plant germplasm conservation for future food security. However, such concerns have gained little empirical support, as recent molecular diversity analyses of improved crop gene pools did not reveal much reduction from early to recent breeding efforts. We conducted a genome‐wide examination of 75 Canadian hard red spring wheat (Triticum aestivum L.) cultivars released from 1845 to 2004 using 370 simple sequence repeat (or SSR) markers that were widely distributed over all 21 wheat chromosomes. A total of 2280 SSR alleles were detected. Allelic reduction occurred in every part of the wheat genome and a majority of the reduced alleles resided in only a few early cultivars. Significant allelic reduction started in the 1930s. Considering 2010 SSR alleles detected in the 20 earliest cultivars, 38% of them were retained, 18% were new, and 44% were lost in the 20 most recent cultivars. The net reduction of the total SSR variation in 20 recent cultivars was 17%. This clear‐cut evidence not only supports the contention that modern plant breeding reduces the genetic diversity of Canadian wheat, but also underlies the need for conserving wheat germplasm and introducing genetic diversity into wheat breeding.
QTL Analysis of Root Architecture Traits and Low Phosphorus Tolerance in an Andean Bean Population
Authors: Cichy Karen A. , Blair Matthew W. , Galeano Mendoza Carlos H. , Snapp Sieglinde S. , Kelly James D. 
Published: January 2009

ABSTRACTTolerance to low P soils is a desirable trait in common bean (Phaseolus vulgarisL.) cultivars grown in acid‐weathered soils. Genetic variability in response to P‐deficient soils exists in the Andean gene pool. G19833, a low P–tolerant indeterminate Andean landrace, has been evaluated for quantitative trait loci (QTL) and tolerance to low P in combination with Mesoamerican parents. Our goal was to expand our understanding of phenotypic traits and QTL from G19833 expressed in an Andean background. An F5:7recombinant inbred line (RIL) population developed from two Andean bean genotypes, G19833 and AND696, a determinate line susceptible to low P soils, was examined under low and high soil P levels in replicated field trials. Phosphorus uptake was reduced by 70% and yield by 60% in low P compared to high P treatments. A linkage map was developed with 11 linkage groups and a total length of 1105 cM. Quantitative trait loci for root growth, seed yield, seed P content, and P use efficiency colocalized near thefingene on linkage group B1. Quantitative trait loci for root growth traits, seed yield, and P uptake colocalized on B11. Quantitative trait loci for root length density (cm cm−3) and root surface area (cm2) did not colocalize with QTL for P uptake. This study indicates that root traits did not play an important role in tolerance to low P soil in an Andean × Andean cross, contrary to previous results with the same P‐efficient Andean parent (G19833) crossed to a Mesoamerican bean genotype.
Development of a PCR Assay and Marker‐Assisted Transfer of Leaf Rust and Stripe Rust Resistance Genes Lr57 and Yr40 into Hard Red Winter Wheats
Authors: Kuraparthy Vasu , Sood Shilpa , See Deven R. , Gill Bikram S. 
Published: January 2009

ABSTRACTThe wheat (Triticum aestivum L.)‐Aegilops geniculata introgression T5DL·5DS‐5MgS(0.95), with stripe rust resistance gene Yr40 and leaf rust resistance gene Lr57, is an effective source of resistance against most isolates of the rust pathogen in Kansas and India. Rust resistance genes Lr57 and Yr40 were transferred to the hard red winter wheat (HRWW) cultivars Jagger and Overley by standard backcrossing and marker‐assisted selection (MAS). PCR‐based cleaved amplified polymorphic sequence (CAPS) markers were developed and used to select backcross F1 plants with rust resistance. Diagnostic polymorphism detected by CAPS marker XLr57/Yr40‐MAS‐CAPS16 was consistent between the resistant source and a set of wheat cultivars selected by the U.S. Wheat Coordinated Agricultural Project. Homozygous BC3F2 plants with rust resistance genes were selected using the Restriction Fragment Length Polymorphisms (RFLP)‐based diagnostic DNA marker polymorphism detected by the wheat grain softness protein (GSP). Deletion of Puroindoline a (Pina‐Mg1) and Puroindoline b (Pinb‐Mg1) gene sequences in the chromosome segment of 5MgS substituting for 5DS of wheat suggests that the backcross derivatives with Lr57/Yr40 can be used to develop hard textured wheats. The HRWW germplasm with Lr57 and Yr40 will provide breeders in the Southern Great Plains with adapted lines having an additional source of resistance that can be used to achieve durability of rust resistance.
Can Changes in Canopy and/or Root System Architecture Explain Historical Maize Yield Trends in the U.S. Corn Belt?
Authors: Hammer Graeme L. , Dong Zhanshan , McLean Greg , Doherty Al , Messina Carlos , Schussler Jeff , Zinselmeier Chris , Paszkiewicz Steve , Cooper Mark 
Published: January 2009

ABSTRACTContinuous increase in the yield of maize (Zea mays L.) in the U.S. Corn Belt has involved an interaction with plant density. A number of contributing traits and mechanisms have been suggested. In this study we used a modeling approach to examine whether changes in canopy and/or root system architecture might explain the observed trends. A maize crop model was generalized so that changes in canopy and root system architecture could be examined. A layered, diurnal canopy photosynthesis model was introduced to predict consequences of change in canopy architecture. A two‐dimensional root exploration model was introduced to predict consequences of change in root system architecture. Field experiments were conducted to derive model parameters for the base hybrid (Pioneer 3394). Simulation studies for various canopy and root system architectures were undertaken for a range of sites, soils, and densities. Simulated responses to density compared well with those found in field experiments. The analysis indicated that (i) change in root system architecture and water capture had a direct effect on biomass accumulation and historical yield trends; and (ii) change in canopy architecture had little direct effect but likely had important indirect effects via leaf area retention and partitioning of carbohydrate to the ear. The study provided plausible explanations and identified testable hypotheses for future research and crop improvement effort.
Biomass Heterosis as the Basis for Grain and Stover Yield Heterosis in Arid Zone Pearl Millet Hybrids
Authors: Bidinger F. R. , Yadav O.P. 
Published: January 2009

ABSTRACTPearl millet [Pennisetum glaucum (L.) R. Br.] single cross hybrids, bred from high‐yielding parental lines in favorable environments, are not well adapted to northwest India's arid zone. The objectives of these experiments were (i) to measure grain and stover yield heterosis in testcrosses of six landrace‐based restorer populations and (ii) to understand how heterosis for biomass and harvest index (HI) affects heterosis for grain and stover yields in crosses of these populations. Six restorer populations and their testcrosses on 10 to 13 A1 male‐sterile lines were evaluated at two arid zone locations of northwest India. Heterosis was calculated as percentage advantage of testcross hybrids over parental restorer population. The range in individual testcross heterosis varied from −3% to +39% for grain yield and from −22% to +17% for stover yield. Variation in biomass heterosis accounted for 55% of the variation in grain yield heterosis and 84% of the variation in stover yield heterosis. Harvest index heterosis accounted for 38% of variation in grain yield heterosis and 13% of stover yield heterosis with a positive heterosis in HI resulting in negative heterosis in stover yield. The testcrosses with the highest biomass heterosis for each restorer population achieved 20% biomass heterosis level (combined with a mean 12% heterosis in HI), resulting in 32% grain yield heterosis and 18% stover yield heterosis. We concluded that heterosis for biomass was the major determinant of grain and stover yield heterosis in pearl millet.