Optical second harmonic generation probe of two-dimensional ferroelectricity

Optical second harmonic generation (SHG) is used as a noninvasive probe of two-dimensional (2D) ferroelectricity in Langmuir-Blodgett (LB) films of copolymer vinylidene fluoride with trifluorethylene. The surface 2D ferroelectric-paraelectric phase transition in the topmost layer of LB films and a thickness independent (almost 2D) transition in the bulk of these films are observed in temperature studies of SHG.Comment: 9 pages, 2 figures, Optics Letters, in prin

Insulin-Like Growth Factor-I Gene Polymorphism Associations with Growth, Body Composition, Skeleton Integrity, and Metabolic Traits

Molecular genetic selection on individual genes is a promising method to genetically improve economically important traits in chickens. A resource population was developed to study the genetics of growth, body composition, skeletal integrity, and metabolism traits. Broiler sires were crossed to dams of 2 diverse, highly inbred lines (Leghorn and Fayoumi), and the F1 birds were intermated by dam line to produce broiler-Leghorn and broiler-Fayoumi F2 offspring. Growth, body composition, skeletal integrity, and hormonal and metabolic factors were measured in 713 F2 individuals. Insulin-like growth factor-I (IGF1) was selected for study as a biological and positional candidate gene. A single nucleotide polymorphism (SNP) was identified between the founder lines in the IGF1 promoter region, and a PCR-RFLP assay was developed. A mixed model was used to statistically analyze associations of IGF1-SNP1 with phenotypic traits. The IGF1-SNP1 had significant associations with most recorded traits, except metabolic traits. Strong interactions between the IGF1 gene and genetic background on growth traits in the 2 F2 populations suggest that genetic interaction is an important aspect for consideration before using the IGF1-SNP1 in marker-assisted selection programs. Several beneficial effects (improved growth, increased breast muscle weight, decreased abdominal fat, and enhanced skeletal integrity) associated with 1 allele indicate the presence of 1 or more loci near IGF1-SNP1 controlling biologically diverse and economically important traits in chickens

Genome-Wide Linkage Analysis to Identify Chromosomal Regions Affecting Phenotypic Traits in the Chicken. III. Skeletal Integrity

Two unique chicken F2 populations generated from a broiler breeder male line and 2 genetically distinct inbred (\u3e99%) chicken lines (Leghorn and Fayoumi) were used for whole genome QTL analysis. Twelve phenotypic skeletal integrity traits (6 absolute and 6 relative traits) were measured or calculated, including bone mineral content, bone mineral density, tibia length, shank length, shank weight, and shank length:shank weight. All traits were also expressed as a percentage of BW at 8 wk of age. Birds were genotyped for 269 microsatellite markers across the entire genome. The QTL affecting bone traits in chickens were detected by the QTL express program. Significance levels were obtained using the permutation test. For the 12 traits, a total of 56 significant QTL were detected at the 5% chromosome-wise significance level, of which 14 and 10 were significant at the 5% genome-wise level for the broiler-Leghorn cross and broiler-Fayoumi cross, respectively. Phenotypic variation for each trait explained by all detected QTL across the genome ranged from 12.0 to 35.6% in the broiler-Leghorn cross and 2.9 to 31.3% in the broiler-Fayoumi cross. Different QTL profiles identified between the 2 related F2 crosses for most traits suggested that genetic background is an important factor for QTL analysis. Study of associations of biological candidate genes with skeletal integrity traits in chickens will reveal new knowledge of understanding biological process of skeletal homeostasis. The results of the current study have identified markers for bone strength traits, which may be used to genetically improve skeletal integrity in chickens by MAS, and to identify the causal genes for these traits

Chicken Quantitative Trait Loci for Growth and Body Composition Associated with Transforming Growth Factor-β Genes1

Transforming growth factor-β (TGF-β) belongs to a large family of multifunctional growth factors that regulate a broad spectrum of biological activities involved in morphogenesis, development, and differentiation. The current study was designed to investigate the effects of TGF-β genes on chicken growth and body composition traits. The Iowa Growth and Composition Resource Population was established by crossing broiler sires with dams from two unrelated highly inbred lines (Leghorn and Fayoumi). The F1 birds were intercrossed, within dam line, to produce two related F2 populations. Body weight and body composition traits were measured in the F 2 population. Primers for TGF-β2, TGF-β3, and TGF-β4 were designed from database chicken sequence. Polymorphisms between parental lines were detected by DNA sequencing, and PCR-RFLP methods were then developed to screen the F2 population. The TGF-β2 polymorphisms between broiler and Leghorn and the TGF-β4 polymorphism between broiler and Fayoumi were associated with traits of skeletal integrity, such as tibia length, bone mineral content, bone mineral density, and the percentage of each measure to BW. The TGF-β3 polymorphism between broilers and Leghorns was associated with traits of growth and body composition, such as BW, average daily gain, weight of breast muscle, abdominal fat pad and spleen, as well as the percentage of these organ weights to BW, and the percentage of shank weight and length to BW. The current research supports the broad effects of TGF-β genes on growth and development of chickens

4-Amino­pyridinium picrate

In the title compound, C5H7N2 +·C6H2N3O7 −, the 4-amino­pyridinium cation is essentially planar (r.m.s. deviation = 0.002 Å). The three nitro groups in the picrate anion are twisted away from the attached benzene ring [dihedral angles = 24.1 (1), 9.3 (3) and 21.4 (1)°]. In the crystal structure, the ions are linked into a three-dimensional network by N—H⋯O and C—H⋯O hydrogen bonds

Nature of the evidence base and frameworks underpinning dietary recommendations for prevention of non-communicable diseases: a position paper from the Academy of Nutrition Sciences

Abstract This Position Paper from the Academy of Nutrition Sciences is the first in a series which describe the nature of the scientific evidence and frameworks that underpin nutrition recommendations for health. This first paper focuses on evidence which underpins dietary recommendations for prevention of non-communicable diseases. It considers methodological advances made in nutritional epidemiology and frameworks used by expert groups to support objective, rigorous and transparent translation of the evidence into dietary recommendations. The flexibility of these processes allows updating of recommendations as new evidence becomes available. For CVD and some cancers, the paper has highlighted the long-term consistency of a number of recommendations. The innate challenges in this complex area of science include those relating to dietary assessment, misreporting and the confounding of dietary associations due to changes in exposures over time. A large body of experimental data is available that has the potential to support epidemiological findings, but many of the studies have not been designed to allow their extrapolation to dietary recommendations for humans. Systematic criteria that would allow objective selection of these data based on rigour and relevance to human nutrition would significantly add to the translational value of this area of nutrition science. The Academy makes three recommendations: (i) the development of methodologies and criteria for selection of relevant experimental data, (ii) further development of innovative approaches for measuring human dietary intake and reducing confounding in long-term cohort studies and (iii) retention of national nutrition surveillance programmes needed for extrapolating global research findings to UK populations.</jats:p

Proceedings of the Rank Forum on Vitamin D

The Rank Forum on Vitamin D was held on 2nd and 3rd July 2009 at the University of Surrey, Guildford, UK. The workshop consisted of a series of scene-setting presentations to address the current issues and challenges concerning vitamin D and health, and included an open discussion focusing on the identification of the concentrations of serum 25-hydroxyvitamin D (25(OH)D) (a marker of vitamin D status) that may be regarded as optimal, and the implications this process may have in the setting of future dietary reference values for vitamin D in the UK. The Forum was in agreement with the fact that it is desirable for all of the population to have a serum 25(OH)D concentration above 25 nmol/l, but it discussed some uncertainty about the strength of evidence for the need to aim for substantially higher concentrations (25(OH)D concentrations . 75 nmol/l). Any discussion of ‘optimal’ concentration of serum 25(OH)D needs to define ‘optimal’ with care since it is important to consider the normal distribution of requirements and the vitamin D needs for a wide range of outcomes. Current UK reference values concentrate on the requirements of particular subgroups of the population; this differs from the approaches used in other European countries where a wider range of age groups tend to be covered. With the re-emergence of rickets and the public health burden of low vitamin D status being already apparent, there is a need for urgent action from policy makers and risk managers. The Forum highlighted concerns regarding the failure of implementation of existing strategies in the UK for achieving current vitamin D recommendations

4-tert-Butyl­pyridinium picrate

In the title compound, C9H14N+·C6H2N3O7 −, the three nitro groups of the picrate anion are twisted out of the plane of the attached benzene ring; the dihedral angles are 32.8 (2), 10.5 (4) and 12.3 (4)°. The pyridinium cations and picrate anions are linked via bifurcated N—H⋯(O,O) hydrogen bonds. The ionic pairs are linked into a ribbon-like structure along [101] by C—H⋯O hydrogen bonds

Properties of Ridges in Elastic Membranes

When a thin elastic sheet is confined to a region much smaller than its size the morphology of the resulting crumpled membrane is a network of straight ridges or folds that meet at sharp vertices. A virial theorem predicts the ratio of the total bending and stretching energies of a ridge. Small strains and curvatures persist far away from the ridge. We discuss several kinds of perturbations that distinguish a ridge in a crumpled sheet from an isolated ridge studied earlier (A. E. Lobkovsky, Phys. Rev. E. 53 3750 (1996)). Linear response as well as buckling properties are investigated. We find that quite generally, the energy of a ridge can change by no more than a finite fraction before it buckles.Comment: 13 pages, RevTeX, acknowledgement adde

Genomic analysis of Ugandan and Rwandan chicken ecotypes using a 600 k genotyping array

Background Indigenous populations of animals have developed unique adaptations to their local environments, which may include factors such as response to thermal stress, drought, pathogens and suboptimal nutrition. The survival and subsequent evolution within these local environments can be the result of both natural and artificial selection driving the acquisition of favorable traits, which over time leave genomic signatures in a population. This study’s goals are to characterize genomic diversity and identify selection signatures in chickens from equatorial Africa to identify genomic regions that may confer adaptive advantages of these ecotypes to their environments. Results Indigenous chickens from Uganda (n = 72) and Rwanda (n = 100), plus Kuroilers (n = 24, an Indian breed imported to Africa), were genotyped using the Axiom® 600 k Chicken Genotyping Array. Indigenous ecotypes were defined based upon location of sampling within Africa. The results revealed the presence of admixture among the Ugandan, Rwandan, and Kuroiler populations. Genes within runs of homozygosity consensus regions are linked to gene ontology (GO) terms related to lipid metabolism, immune functions and stress-mediated responses (FDR \u3c 0.15). The genes within regions of signatures of selection are enriched for GO terms related to health and oxidative stress processes. Key genes in these regions had anti-oxidant, apoptosis, and inflammation functions. Conclusions The study suggests that these populations have alleles under selective pressure from their environment, which may aid in adaptation to harsh environments. The correspondence in gene ontology terms connected to stress-mediated processes across the populations could be related to the similarity of environments or an artifact of the detected admixture