1,595 research outputs found
Changes in muscularity with growth and its relationship with other carcass traits in three terminal sire breeds of sheep
Data were available for 160 sheep (50 Suffolk males, 50 Suffolk females, 40 Texel males and 20 Charollais males). One fifth of animals within each breed and sex were slaughtered at each of 14, 18 or 22 weeks of age and two-fifths slaughtered at 26 weeks. After slaughter linear measurements were taken on the carcass. The left side of each carcass was then separated into eight joints and each joint dissected into lean, bone and fat. Five muscularity measures (three for the longissimus thoracis et lumborum (LTL) muscle, one for the hind leg and one for the whole carcass) and one for the shape of the LTL cross-section (depth : width) were calculated. With the exception of one measure for the LTL muscularity increased with growth. Rates of increase in most measures were higher in Texels that in each of the other breads, but were not different between the male and female Suffolks or between the Suffolk and Charollais lambs. Increase in most muscularity measures at 17 constant live weight were associated with increases in lean to bone ratio and carcass lean content. Associations with fat content were either non-significant or weak. Correlations between the three measures of muscularity for the LTL were high. Correlations between the whole carcass measure and those within different regions were moderate to high in the Texels but lower in the Suffolk and Charollais breeds. The same was true for correlations between the LTL measures and hind leg muscularity. If muscularity throughout the carcass is to be described effectively, measures in more than one region may be required, particularly in the Suffolk and Charollais breeds
Changes in muscularity with growth and its relationship with other carcass traits in three terminal sire breeds of sheep
Flat-band localization and interaction-induced delocalization of photons
Advances in quantum engineering have enabled the design, measurement, and
precise control of synthetic condensed matter systems. The platform of
superconducting circuits offers two particular capabilities: flexible
connectivity of circuit elements that enables a variety of lattice geometries,
and circuit nonlinearity that provides access to strongly interacting physics.
Separately, these features have allowed for the creation of curved-space
lattices and the realization of strongly correlated phases and dynamics in
one-dimensional chains and square lattices. Missing in this suite of
simulations is the simultaneous integration of interacting particles into
lattices with unique band dispersions, such as dispersionless flat bands. An
ideal building block for flat-band physics is the Aharonov-Bohm cage: a single
plaquette of a lattice whose band structure consists entirely of flat bands.
Here, we experimentally construct an Aharonov-Bohm cage and observe the
localization of a single photon, the hallmark of all-bands-flat physics. Upon
placing an interaction-bound photon pair into the cage, we see a delocalized
walk indicating an escape from Aharonov-Bohm caging. We further find that a
variation of caging persists for two particles initialized on opposite sites of
the cage. These results mark the first experimental observation of a quantum
walk that becomes delocalized due to interactions and establish superconducting
circuits for studies of flat-band-lattice dynamics with strong interactions.Comment: 8 + 9 pages, 4 + 12 figures, 0 + 2 tables; modified title, added a
supplementary figure, and modified the definition used for tunneling tim
On Exchange of Orbital Angular Momentum Between Twisted Photons and Atomic Electrons
We obtain an expression for the matrix element for a twisted
(Laguerre-Gaussian profile) photon scattering from a hydrogen atom. We consider
photons incoming with an orbital angular momentum (OAM) of ,
carried by a factor of not present in a plane-wave or pure
Gaussian profile beam. The nature of the transfer of units of OAM from
the photon to the azimuthal atomic quantum number of the atom is investigated.
We obtain simple formulae for these OAM flip transitions for elastic forward
scattering of twisted photons when the photon wavelength is large
compared with the atomic target size , and small compared the Rayleigh range
, which characterizes the collimation length of the twisted photon beam.Comment: 16 page
Prenatal maternal immune activation causes epigenetic differences in adolescent mouse brain
Epigenetic processes such as DNA methylation have been implicated in the pathophysiology of neurodevelopmental disorders including schizophrenia and autism. Epigenetic changes can be induced by environmental exposures such as inflammation. Here we tested the hypothesis that prenatal inflammation, a recognized risk factor for schizophrenia and related neurodevelopmental conditions, alters DNA methylation in key brain regions linked to schizophrenia, namely the dopamine rich striatum and endocrine regulatory centre, the hypothalamus. DNA methylation across highly repetitive elements (long interspersed element 1 (LINE1) and intracisternal A-particles (IAPs)) were used to proxy global DNA methylation. We also investigated the Mecp2 gene because it regulates transcription of LINE1 and has a known association with neurodevelopmental disorders. Brain tissue was harvested from 6 week old offspring of mice exposed to the viral analog PolyI:C or saline on gestation day 9. We used Sequenom EpiTYPER assay to quantitatively analyze differences in DNA methylation at IAPs, LINE1 elements and the promoter region of Mecp2. In the hypothalamus, prenatal exposure to PolyI:C caused significant global DNA hypomethylation (t=2.44, P=0.019, PolyI:C mean 69.67%, saline mean 70.19%), especially in females, and significant hypomethylation of the promoter region of Mecp2, (t=3.32, P=0.002; PolyI:C mean 26.57%, saline mean 34.63%). IAP methylation was unaltered. DNA methylation in the striatum was not significantly altered. This study provides the first experimental evidence that exposure to inflammation during prenatal life is associated with epigenetic changes, including Mecp2 promoter hypomethylation. This suggests that environmental and genetic risk factors associated with neurodevelopmental disorders may act upon similar pathways. This is important because epigenetic changes are potentially modifiable and their investigation may open new avenues for treatment
Biological invasion hotspots: a trait-based perspective reveals new sub-continental patterns
Invader traits (including plant growth form) may play an important, and perhaps overlooked, role in determining macroscale patterns of biological invasions and therefore warrant greater consideration in future investigations aimed at understanding these patterns. To assess this need, we used empirical data from a national-level survey of forest in the contiguous 48 states of the USA to identify geographic hotspots of forest plant invasion for three distinct invasion characteristics: invasive species richness, trait richness (defined as the number of the five following plant growth forms represented by the invasive plants present at a given location: forbs, grasses, shrubs, trees, and vines), and species richness within each growth form. Three key findings emerged. 1) Th e hotspots identified encompassed from 9 to 23% of the total area of our study region, thereby revealing many forests to be not only invaded, but highly invaded. 2) Substantial spatial disagreement among hotspots of invasive species richness, invasive trait richness, and species richness of invasive plants within each growth form revealed many locations to be hotspots for invader traits, or for particular growth forms of invasive plants, rather than for invasive plants in general. 3) Despite eastern forests exhibiting higher levels of plant invasion than western forests, species richness for invasive forbs and grasses in the west were respectively greater than and equivalent to levels found in the east. Contrasting patterns between eastern and western forests in the number of invasive species detected for each growth form combined with the spatial disagreement found among hotspot types suggests trait-based variability in invasion drivers. Our findings reveal invader traits to be an important contributor to macroscale invasion patterns
Explorations in anatomy: the remains from Royal London Hospital
This paper considers the faunal remains from recent excavations at the Royal London Hospital. The remains date to the beginning of the 19th century and offer an insight into the life of the hospital's patients and practices of the attached medical school. Many of the animal remains consist of partially dissected skeletons, including the unique finds of Hermann's tortoise (Testudo hermanni) and Cercopithecus monkey. The hospital diet and developments in comparative anatomy are discussed by integrating the results with documentary research. They show that zooarchaeological study of later post-medieval material can significantly enhance our understanding of the exploitation of animals in this perio
The modulation of reading strategies by language opacity in early bilinguals: an eye movement study
Converging evidences from eye movement experiments indicate that linguistic contexts influence reading strategies. However, the question of whether different linguistic contexts modulate eye movements during reading in the same bilingual individuals remains unresolved. We examined reading strategies in a transparent (German) and an opaque (French) language of early, highly proficient French–German bilinguals: participants read aloud isolated French and German words and pseudo- words while the First Fixation Location (FFL), its duration and latency were measured. Since transparent linguistic contexts and pseudo-words would favour a direct grapheme/phoneme conversion, the reading strategy should be more local for German than for French words (FFL closer to the beginning) and no difference is expected in pseudo-words’ FFL between contexts. Our results confirm these hypotheses, providing the first evidence that the same individuals engage different reading strategy depending on language opacity, suggesting that a given brain process can be modulated by a given context
Imprints of the Quantum World in Classical Mechanics
The imprints left by quantum mechanics in classical (Hamiltonian) mechanics
are much more numerous than is usually believed. We show Using no physical
hypotheses) that the Schroedinger equation for a nonrelativistic system of
spinless particles is a classical equation which is equivalent to Hamilton's
equations.Comment: Paper submitted to Foundations of Physic
Effect of mode of action of the Texel Muscling QTL (TM-QTL) on carcass traits in purebred Texel lambs
- …