Multi-location Study Research Articles

Variabilité des teneurs et compositions des composés mineurs dans l’huile de tournesol au cours du développement du capitule

Sunflower oil is rich in polyunsaturated fatty acids and in minor components (1% of the oil fraction) including phytosterols, tocopherols, waxes and others components. This study evaluates the content and composition of the phytosterols in four sunflower hybrids during two growing seasons (2002 & 2003) and in seven more hybrids in a multilocal study in 2003. The phytosterol content in the maturing seeds was followed from flowering stage till full maturity. The kinetics of phytosterols accumulation was similar to that of fatty acids : a rapid increase until 25 Days After Flowering DAF and a stabilization after 50 DAF. However, the temperature during the seed development induced changes in the phytosterol content, since the total amount of phytosterols was significantly increased by high temperatures in some hybrids. On the other hand, the comparison of phytosterol content in the 11 hybrids tested in 2003 shows significant differences in phytosterol content between hybrids and low location X hybrid interaction. In this study the environment effect was the major source of variation. This study shows that phytosterol content in sunflower oil can be promoted though combined action on selection and growth conditions.

Revisiting children ‘home on trial’ in the context of current concerns about the costs and effectiveness of the looked‐after children system: findings from an exploratory study

ABSTRACTStatute and practice relating to s.31 part IV of The Children Act 1989 allow children subject to care orders to be placed at home with their parent(s). It is not uncommon for the courts to accept a plan for children to return home at the final hearing of care proceedings at which full care orders are granted. In such instances, children retain looked‐after status but, in terms of their day‐to‐day care, are looked after by parent(s). Whilst there are a small number of studies conducted in the 1990s relating to children ‘home on trial’, there is a much more limited recent literature. It is important to revisit this population of children, given current concerns about the burgeoning costs of child care proceedings and the looked‐after children system (LAC). This paper reports on a small‐scale exploratory study in one north‐west local authority area. Consisting of a file study and interviews with parents and professionals, the study examines the factors that contributed to initial removal of children to public care, the impact of the LAC system for children ‘home on trial’, stability of placements at home, as well as issues to do with the discharge of care orders. Particular attention is drawn to lone father headed households, a social group over‐represented in our sample. The study aims to inform further multi‐location studies.

Spatio‐temporal dynamics of corn rootworm, Diabrotica spp., adults and their spatial association with environment

AbstractMultiyear and multilocation studies were conducted to investigate the within‐ and the between‐year spatial dynamics of corn rootworms Diabrotica spp. (Coleoptera: Chrysomelidae), adults and their spatial associations with environmental factors in cornfields. Grid‐based spatial sampling was conducted by trapping adults emerging from the soil (i.e., ‘emergence‐trap counts’) and by counting the number of adults in the ear zone of corn plant (i.e., ‘ear‐zone count’). Spatial analysis with distance indices (SADIE) was used to determine spatial distribution patterns and to investigate spatial associations. Ear‐zone counts and emergence‐trap counts were spatially dynamic within a year and more frequently aggregated in the middle of growing seasons and random early and late in the season. However, during the peak population periods, spatial distribution of ear‐zone counts and emergence‐trap counts were significantly consistent between years, indicating predictability of future spatial distributions. Spatial distribution of emergence‐trap counts and ear‐zone counts were positively associated with soil moisture and presence of corn plants with silks, respectively. This study demonstrated that within‐year spatial distribution patterns were dynamic and that there was between‐year spatial consistency of corn rootworm adult distributions. Such information can be used to improve preventative management of corn rootworms.

Variabilité des teneurs et compositions des composés mineurs dans l’huile de tournesol au cours du développement du capitule

The sunflower oil is rich in polyunsaturated fatty acids and in minor components (1 % of the oil fraction) including phytosterols, tocopherols, wax and others components. This study evaluates the content and composition of the tocopherols in four sunflower hybrids during two growing seasons (2002 & 2003) and in seven supplemented hybrids during a multilocal study in 2003. The accumulation of tocopherol in the maturing seeds was studied followed from flowering stage till full maturity. The kinetics of tocopherols was similar to fatty acids: rapid increase prior to 25 Days After Flowering (DAF) and then stabilization after 50 DAF. However, the temperature during the seed development induced changes in the tocopherol content, since the total amount of tocopherols was significantly reduced by high temperatures. On the other hand, the comparison of tocopherol content in the 11 hybrids tested clearly shows the impact of genetic factor concerning the level of tocopherols expressed in the seed. However in this study the genotype-environment interaction was slight. Data provided by this study show that content of tocopherol in the sunflower oil can be promoted though combined action on selection and growth conditions.

Variabilité des teneurs et compositions des composés mineurs dans l’huile de tournesol au cours du développement du capitule

1 Universite de Toulouse ; Ecole d’Ingenieurs de Purpan ; Laboratoire d’Agro-Physiologie ; 75, voie du TOEC, BP 57611, F-31076 Toulouse Cedex 03, France 2 ONIDOL, Organisation nationale interprofessionnelle des oleagineux, 12, avenue George V, 75008 Paris, France 3 ASEDIS-SO, 39, chemin Virebent, 31200 Toulouse, France 4 COGNIS-France, Usine d’Estarac, 31 360 Boussens, France Abstract: Sunflower oil is rich in polyunsaturated fatty acids and in minor components (1 % of the oil fraction) including phytosterols, tocopherols, waxes and others components. This study evaluates the content and composition of the phytosterols in four sunflower hybrids during two growing seasons (2002 & 2003) and in seven more hybrids in a multilocal study in 2003. The phytosterol content in the maturing seeds was followed from flowering stage till full maturity. The kinetics of phytosterols accumulation was similar to that of fatty acids : a rapid increase until 25 Days After Flowering DAF and a stabilization after 50 DAF. However, the temperature during the seed development induced changes in the phytosterol content, since the total amount of phytosterols was significantly increased by high temperatures in some hybrids. On the other hand, the comparison of phytosterol content in the 11 hybrids tested in 2003 shows significant differences in phytosterol content between hybrids and low location X hybrid interaction. In this study the environment effect was the major source of variation. This study shows that phytosterol content in sunflower oil can be promoted though combined action on selection and growth conditions.

Factors Affecting Cure and Somatic Cell Count After Pirlimycin Treatment of Subclinical Mastitis in Lactating Cows

This study investigated the associations of both bacteriological cure and quarter somatic cell count (SCC) after intramammary antibiotic treatment with treatment duration, cow characteristics, and pretreatment bacteriology and SCC. For the purpose of this paper, data from 2 treatment groups in each of 2 multi-location studies were selected. These studies were conducted to evaluate the efficacy of daily intramammary infusions with 50mg of pirlimycin hydrochloride for the treatment of subclinical mastitis. Data from study 1 allowed for comparison of a group of cows that received pirlimycin intramammarily for 2 d with a group that received no treatment, and study 2 provided data for comparison of pirlimycin for 2 d with pirlimycin for 8 d. Quarter milk samples from cows with a high monthly SCC were tested for bacteriology and SCC. If one or more quarters had both a positive bacteriology and an SCC ≥300,000 cells/mL, the cow was enrolled and randomly allocated to a treatment group. Enrolled cows were monitored for clinical mastitis and other disease for 4 wk after treatment initiation. At 3 and 4 wk after treatment initiation, milk samples were taken from each enrolled quarter to determine the SCC and conduct a bacteriological culture. Bacteriological culture results were interpreted such that quarters where the same bacterial species was cultured before treatment and found in at least 1 of the 2 posttreatment samples were considered a failure. The analysis of SCC used a mixed linear model (SAS proc mixed) and the analysis of bacteriological cure used a mixed logistic model (SAS glimmix macro). Bacteriological cure rate was significantly higher for lower parity, lower number of colonies in the pretreatment culture, longer treatment duration, and for streptococci compared with Staphylococcus aureus. However, treatment regimen affected bacteriological cure differently in major than in minor pathogens and there was a significant interaction of treatment regimen with stage of lactation. Posttreatment SCC was significantly higher with increasing parity, in rear quarters, and with shorter duration of treatment. In the group of second and third parity animals, post-treatment SCC was more reduced in front quarters than in rear quarters. Also, the difference in posttreatment SCC between younger and older cows increased with higher pretreatment SCC. In conclusion, when predicting bacteriological cure following treatment of subclinical mastitis during lactation both treatment regimen and other risk factors need to be considered. The other risk factors may vary with treatment regimen. Posttreatment SCC was associated with treatment regimen, other risk factors, and interactions among the other risk factors; but these other risk factors did not vary significantly with treatment regimen.

Estrus synchronization of replacement beef heifers by using GnRH, prostaglandin F2α (PGF), and progesterone (CIDR): a multi-location study (2004)

Our objectives were to determine whether a fixed-timed artificial insemination (TAI) protocol could yield similar fertility rates to a protocol requiring detection of estrus and whether an injection of gonadotropin hormone-releasing hormone (GnRH) at CIDR (vaginal insert containing progesterone) insertion enhances pregnancy rates. Replacement beef heifers (n=2,077) from 12 locations were assigned randomly to each of four estrussynchronization protocols. All heifers received a CIDR for 7 days, and an injection of prostaglandin F2α(PGF) on the day of CIDR removal. For treatment EAI, heifers were observed for estrus for 84 hours after PGF administration and were inseminated 6 to 12 hours after observed estrus. Any heifer not detected in estrus was injected with GnRH, followed by TAI. For treatment GnRH+EAI, heifers were treated as those for EAI, but also received GnRH at the time of CIDR insertion. For treatment TAI, heifers received a single TAI at 60 hours after PGF administration. For treatment GnRH+TAI, heifers were treated as those for TAI, but also received GnRH at CIDR insertion. The percentage of heifers cycling at the initiation of estrus-synchronization was 91%; the percentage of cycling heifers among locations ranged from 78 to 100%. Overall pregnancy rates among locations ranged from 38 to 74%. Pregnancy rates were 57.3, 54.5, 53.1, and 49.1% for GnRH+EAI, EAI, GnRH+TAI, and TAI, respectively. Although no statistically significant differences in pregnancy rates among treatments were observed, the GnRH+EAI treatment achieved the numerically greatest pregnancy rates. In addition, the GnRH+TAI protocol provides an alternative that allows producers to synchronize heifers without detection of estrus.

Estrus synchronization of suckled beef cows by using GnRH, prostaglandin F2α (PGF), and progesterone (CIDR): a multi-location study (2004)

Our objectives were to determine whether a fixed-time artificial insemination (TAI) protocol could yield pregnancy rates similar to a protocol requiring detection of estrus and whether inclusion of a CIDR (a vaginal insert containing progesterone) in protocols using gonadotropin-releasing hormone (GnRH) and prostaglandin F2α (PGF) would enhance fertility. Postpartum suckled beef cows (n = 2,630) from 14 locations were assigned randomly to each of five estrus-synchronization protocols using PGF with GnRH and(or) a CIDR. Protocols were Control, CO-Synch, COSynch+CIDR, Hybrid-Synch, and HybridSynch+CIDR. The percentage of cows cycling at the initiation of estrus synchronization was 66.8%, the percentage of cycling cows ranging from 38 to 90% among locations. Overall pregnancy among locations ranged from 39% to 67%. Pregnancy rates were greatest for the Hybrid-Synch+CIDR (57.9%) treatment, although not significantly different from the CO-Synch+CIDR (53.6%) and Hybrid-Synch (53.0%) treatments, but greater than the Control (52.3%) and CO-Synch (43.4%), which yielded the poorest pregnancy rates. Overall, the Hybrid-Synch+CIDR protocol (AI after detected estrus for 3 days, and then a clean-up TAI) achieved the greatest pregnancy rates, but CO-Synch+CIDR is a reliable, fixed-time AI protocol that gives producers the option to eliminate detection of estrus.

Introgression of a quantitative trait locus for yield from Glycine soja into commercial soybean cultivars.

The value of exotic germplasm in broadening the genetic base of most crops has been demonstrated many times. However, the difficulties involved in working with exotic germplasm have limited their utility in plant breeding. Unwanted linkages often thwart the successful incorporation of beneficial exotic genes into commercial lines. Thus, the use of exotics in traditional breeding makes the process of crop improvement a tedious, time-consuming and expensive endeavor. The availability of molecular markers makes it possible to isolate specific genomic regions and transfer them into commercial varieties with minimal linkage drag. We found a yield-enhancing quantitative trait locus (QTL) from Glycine soja (Siebold and Zucc.) by evaluating a population of 265 BC(2) individuals from a cross between HS-1 and PI 407305. The yield QTL was located on linkage group B2(U26) of the soybean [Glycine max (L.) Merrill] genetic linkage map. In a 2-year, multi-location study, individuals carrying the PI 407305 haplotype at the QTL locus demonstrated a 9.4% yield advantage over individuals that did not contain the exotic haplotype. When tested in a more uniform "HS-1-like" background in two locations, we observed an 8% yield advantage for lines that carry the PI 407305 haplotype. We further assessed the QTL effect in various elite soybean genetic backgrounds. The yield effect was consistently observed in only two of six genetic backgrounds. Individuals carrying the PI 407305 haplotype at the QTL locus had a 9% yield advantage in yield trials across locations. Despite the limited adaptability of this yield-QTL across genetic backgrounds, this study demonstrates the potential of exotic germplasm for yield enhancement in soybean.

Ovulation synchronization with progestins prior to a Cosynch protocol in beef cows (2001)

A multi-location study was conducted using suckled beef cows in Minnesota and Kansas to test the benefit of adding a source of progestin to the Cosynch ovulation synchronization protocol (injections of GnRH, 7 days before and 48 hr after an injection of PGF2, with a fixed-time artificial insemination (AI) administered at the same time as the second GnRH injection). Feeding melengestrol acetate (MGA) for 14 days followed in 12 days by the Cosynch protocol was compared to the Cosynch protocol with the addition of a progesterone-impregnated insert (CIDR) placed in the vagina for 7 days concurrent with the first GnRH injection. Pregnancy rates after the first AI (timed AI) were 22% greater with the CIDR insert, whereas conception rates for those cows returning to estrus were greater for cows previously fed MGA. Total pregnant cows after two inseminations were 64% for CIDR cows and 59% for MGA cows.

Influence of Seaweed Extract-treated Tall Fescue on Bovine Antioxidant Activity, Immune Response, and Carcass Characteristics

It has been well documented that tall fescue (Festuca arundinaceaa) infected with the endophyte fungus Neotyphodium coenophialumb is associated with production and health problems in beef cattle. Various approaches to overcome the negative, animal-related effects of the endophyte have been investigated without consistent and/or economically feasible outcome. This multi-location study investigated effects of applying Tasco™ Forage, a proprietary seaweed-based product, to endophyte-infected fescue to improve animal health and production.

Research ethics committees at work: the experience of one multi-location study.

To report the outcome of applications to 43 research ethics committees. Four regional health authorities in England. The research ethics committees varied considerably in their practices. The time lapse until notification of the outcome of the approval ranged from just under one week to 23 weeks with a mean of 8.6 weeks. Four research ethics committees failed to notify the research team of an outcome of their request for approval. A national research ethics committee is needed to review national and multi-location research studies in the light of the fragmented and variable practice of local research ethics committees.

GENERALIZED LINEAR MIXED MODELS - AN OVERVIEW

Generalized linear models provide a methodology for doing regression and ANOV A-type analysis with data whose errors are not necessarily normally-distributed. Common applications in agriculture include categorical data, survival analysis, bioassay, etc. Most of the literature and most of the available computing software for generalized linear models applies to cases in which all model effects are fixed. However, many agricultural research applications lead to mixed or random effects models: split-plot experiments, animal- and plant-breeding studies, multi-location studies, etc. Recently, through a variety of efforts in a number of contexts, a general framework for generalized linear models with random effects, the "generalized linear mixed model," has been developed . The purpose of this presentation is to present an overview of the methodology for generalized mixed linear models. Relevant background, estimating equations, and general approaches to interval estimation and hypothesis testing will be presented. Methods will be illustrated via a small data set involving binary data .

Performance of maize—soybean intercrop combination in the tropics: Results of a multi-location study

Results of an experiment conducted at 14 locations in seven countries during 1976–1979 under the coordination of the East-West Center, Hawaii, are discussed. This study compares the performance of maize—soybean intercrop with the component sole crops at different N levels applied to maize. Intercropping generally gave greater combined yields and monetary returns than obtained from either crop grown alone. On the basis of land equivalent ratio, yield advantage from intercropping varied from 64% at zero N to 42% at 100% of the recommended rate of N application to maize. Returns from intercropping at zero nitrogen were 61% higher than sole maize and 44% higher than sole soybean. Maize—soybean intercrop appears to be particularly well-suited for small farmers in developing countries who operate at subsistence level and use little or no fertilizer. Increased research effort is suggested to identify other crop combinations for use under various ecosystems and management levels, develop efficient methods of fertilising the cereal and to understand benefits of legumes in intercropping.

Influence of weather sequence on rabi jowar crop yield at Solapur

The variations in the grain. and fodder yield of M-35-1 jowar in sowing date trials at Solapur in two typical rainfall years are examined from the meteorological standpoint. The temperature regimes in the vegetative and flowering phases, moisture accretion at or near crop emergence, rainfall Incidence in the vegetative crop phase and soil moisture storage, emerge as the factors chiefly affecting ear development, initial crop stand fodder yield and grain out-turn respectively. The final yield is a result of the interplay of the above effects. More such multi-location studies appear warranted.