402 research outputs found
Xylanase and xylo- oligosaccharide prebiotic improve the growth performance and concentration of potentially prebiotic oligosaccharides in the ileum of broiler chickens
The objective of this study was to investigate the effect of supplementing broiler diets with xylanase or xylo- oligosaccharide (XOS) on growth performance, the concentration of non-starch polysaccharide (NSP) hydrolysis products in the ileum and concentration of short chain fatty acids (SCFA) in the caeca of broiler chickens.
In total, 500 male Ross 308 broilers were used in this 29-day (d) study. The treatments were organised into a 2×2 plus 1 factorial arrangement consisting of two additives (xylanase or XOS) at two levels (low or high) plus a control treatment with no additives. This gave five treatments with 100 bird in each treatment group. The diets were slightly deficient in protein by 20 g/kg and energy by 1 MJ/kg.
On d 14 and 28, two birds per pen were euthanised, the caeca content collected and analysed for short chain fatty acid (SCFA) concentration. On d 29, six birds per pen were euthanised and ileal digesta were collected and analysed for the concentration of NSP fractions.
On d 14, caecal acetic acid, iso-butyric acid, iso-valeric acid, n-valeric acid and total SCFA concentrations were significantly greater (P≤0.05) when diets were supplemented with XOS compared with xylanase.
Ileal concentration of arabinose, galactose and glucuronic acid (GlucA2) were significantly greater (P≤0.05) in the insoluble NSP fraction when diets were supplemented with a high level of xylanase, compared with the control treatment. Ileal concentration of fructose was significantly greater (P≤0.05) in the water soluble NSP when a high level of xylanase or low level of XOS were included in the diet compared with the control.
It was concluded that xylanase and XOS had similar effects on NSP concentration and SCFA in the caeca, although there was little effect on performance. This observation demonstrated further benefits of xylanase supplementation in wheat-based broiler diets beyond digesta viscosity reduction and the release of extra nutrients
A role for glycosaminoglycans in the development of collagen fibrils
AbstractExtensive data on the glycosaminoglycan (GAG) composition and the collagen fibril diameter distribution have been collected for a diverse range of connective tissues. It is shown that tissues with the smallest diameter collagen fibrils (mass-average diameter < 60 nm) have high concentrations of hyaluronic acid and that tissues with the largest diameter collagen fibrils (mass-average diameter ∼200 nm) have high concentrations of dermatan sulphate. It is suggested that the lateral growth of fibrils beyond a diameter of about 60 nm is inhibited by the presence of an excess of hyaluronic acid but that this inhibitory effect may be removed by an increasing concentration of chondroitin sulphate and/or dermatan sulphate. It is also postulated that high concentrations of chondroitin sulphate will inhibit fibril growth beyond a mass-average diameter of ∼150 nm. Such an inhibition may in turn be removed by an increasing concentration of dermatan sulphate such that it becomes the dominant GAG present in the tissue
Theoretical considerations in determining allometric growth within instars of crustaceans, with special reference to Americamysis bahia
Allometry in crustaceans is typically considered growth over several instars primarily because crustaceans are presumed to grow only during ecdysis (discontinuous growth). Using theoretical distributions of the sizes of two morphometric variables over several instars, four theoretical instar allometry models are postulated: continuous allometry (indiscrete and discrete); discontinuous allometry (indiscrete and discrete); mixed allometry (simple or complex); and two‐rate continuous allometry. The estimates of proportions of allometry within the instars are determined using Y = f(X) and X = f(Y) for variables X and Y. The amount of allometry in each variable is estimated using the mean ± standard deviation on the independent variable. Application of these theoretical instar allometry models using carapace and abdomen sizes in six instars indicates Americamysis bahia experiences two‐rate continuous allometry, rather than “traditional” discontinuous allometry, with 85% or more of total growth occurring in the intermolt phase, and with the abdomen accounting for about 60% of the expansion.http://wileyonlinelibrary.com/journal/jez2020-11-01hj2020Paraclinical Science
Relaxin family peptide receptors in GtoPdb v.2023.1
Relaxin family peptide receptors (RXFP, nomenclature as agreed by the NC-IUPHAR Subcommittee on Relaxin family peptide receptors [23, 119]) may be divided into two pairs, RXFP1/2 and RXFP3/4. Endogenous agonists at these receptors are heterodimeric peptide hormones structurally related to insulin: relaxin-1, relaxin, relaxin-3 (also known as INSL7), insulin-like peptide 3 (INSL3) and INSL5. Species homologues of relaxin have distinct pharmacology and relaxin interacts with RXFP1, RXFP2 and RXFP3, whereas mouse and rat relaxin selectively bind to and activate RXFP1 [260]. relaxin-3 is the ligand for RXFP3 but it also binds to RXFP1 and RXFP4 and has differential affinity for RXFP2 between species [259]. INSL5 is the ligand for RXFP4 but is a weak antagonist of RXFP3. relaxin and INSL3 have multiple complex binding interactions with RXFP1 [267] and RXFP2 [132] which direct the N-terminal LDLa modules of the receptors together with a linker domain to act as a tethered ligand to direct receptor signaling [262]. INSL5 and relaxin-3 interact with their receptors using distinct residues in their B-chains for binding, and activation, respectively [321, 152]
UPDATE ON THE SATELLITE TAGGING OF ATLANTIC AND MEDITERRANEAN SWORDFISH
This paper provides an update of the study on habitat use for swordfish, developed within the
working plan of the Swordfish Species Group of ICCAT. A total of 26 miniPAT tags have been
deployed so far in the North (n=13) and South Atlantic (n=9) and the Mediterranean (n=4). Data
from eight tags was analysed for horizontal and vertical habitat use. These preliminary results
showed swordfish moved in several directions, travelling considerable distances in both the
North and South stocks. Swordfish spent most of the daytime in deeper waters with a mean of
540.8 m, being closer to the surface during nighttime (mean=78.3 m). The deepest dive recorded
was of 1480 m. Regarding temperature, swordfish inhabited waters with temperatures ranging
from 3.9ºC to 30.5ºC with a mean of 11.3ºC during daytime and 21.7ºC during nighttime. The
main plan for the next phase of the project is to continue the tag deployment during 2022 in
several regions of the Atlantic Ocean and Mediterranean Sea. Currently 11 tags are with the
participating CPCs and nine tags are still to be attributed.En prens
Vacuum local and global electromagnetic self-energies for a point-like and an extended field source
We consider the electric and magnetic energy densities (or equivalently field
fluctuations) in the space around a point-like field source in its ground
state, after having subtracted the spatially uniform zero-point energy terms,
and discuss the problem of their singular behavior at the source's position. We
show that the assumption of a point-like source leads, for a simple Hamiltonian
model of the interaction of the source with the electromagnetic radiation
field, to a divergence of the renormalized electric and magnetic energy density
at the position of the source. We analyze in detail the mathematical structure
of such singularity in terms of a delta function and its derivatives. We also
show that an appropriate consideration of these singular terms solves an
apparent inconsistency between the total field energy and the space integral of
its density. Thus the finite field energy stored in these singular terms gives
an important contribution to the self-energy of the source. We then consider
the case of an extended source, smeared out over a finite volume and described
by an appropriate form factor. We show that in this case all divergences in
local quantities such as the electric and the magnetic energy density, as well
as any inconsistency between global and space-integrated local self-energies,
disappear.Comment: 8 pages. The final publication is available at link.springer.co
Sex determination in the Giant fish of Amazon Basin, Arapaima gigas (Osteoglossiformes, Arapaimatidae), using laparoscopy
Towards a New Proof of Anderson Localization
The wave function of a non-relativistic particle in a periodic potential
admits oscillatory solutions, the Bloch waves. In the presence of a random
noise contribution to the potential the wave function is localized. We outline
a new proof of this Anderson localization phenomenon in one spatial dimension,
extending the classical result to the case of a periodic background potential.
The proof makes use of techniques previously developed to study the effects of
noise on reheating in inflationary cosmology, employing methods of random
matrix theory
Multimodal augmented reality tangible gaming
This paper presents tangible augmented reality gaming environment that can be used to enhance entertainment using a multimodal tracking interface. Players can interact using different combinations between a pinch glove, a Wiimote, a six-degrees-of-freedom tracker, through tangible ways as well as through I/O controls. Two tabletop augmented reality games have been designed and implemented including a racing game and a pile game. The goal of the augmented reality racing game is to start the car and move around the track without colliding with either the wall or the objects that exist in the gaming arena. Initial evaluation results showed that multimodal-based interaction games can be beneficial in gaming. Based on these results, an augmented reality pile game was implemented with goal of completing a circuit of pipes (from a starting point to an end point on a grid). Initial evaluation showed that tangible interaction is preferred to keyboard interaction and that tangible games are much more enjoyable
Synthesis of fluorescent analogs of relaxin family peptides and their preliminary in vitro and in vivo characterization
Relaxin, a heterodimeric polypeptide hormone, is a key regulator of collagen metabolism and multiple vascular control pathways in humans and rodents. Its actions are mediated via its cognate G-protein-coupled receptor, RXFP1 although it also "pharmacologically" activates RXFP2, the receptor for the related, insulin-like peptide 3 (INSL3), which has specific actions on reproduction and bone metabolism. Therefore, experimental tools to facilitate insights into the distinct biological actions of relaxin and INSL3 are required, particularly for studies of tissues containing both RXFP1 and RXFP2. Here, we chemically functionalized human (H2) relaxin, the RXFP1-selective relaxin analog H2:A(4-24)(F23A), and INSL3 to accommodate a fluorophore without marked reduction in binding or activation propensity. Chemical synthesis of the two chains for each peptide was followed by sequential regioselective formation of their three disulfide bonds. Click chemistry conjugation of Cy5.5 at the B-chain N-terminus, with conservation of the disulfide bonds, yielded analogs displaying appropriate selective binding affinity and ability to activate RXFP1 and/or RXFP2 in vitro. The in vivo biological activity of Cy5.5-H2 relaxin and Cy5.5-H2:A(4-24)(F23A) was confirmed in mice, as acute intracerebroventricular (icv) infusion of these peptides (but not Cy5.5-INSL3) stimulated water drinking, an established behavioral response elicited by central RXFP1 activation. The central distribution of Cy5.5-conjugated peptides was examined in mice killed 30 min after infusion, revealing higher fluorescence within brain tissue near-adjacent to the cerebral ventricle walls relative to deeper brain areas. Production of fluorophore-conjugated relaxin family peptides will facilitate future pharmacological studies to probe the function of H2 relaxin/RXFP1 and INSL3/RXFP2 signaling in vivo while tracking their distribution following central or peripheral administration
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