8,958 research outputs found
Intestinal Effects of Dietary Betaine in Piglets
The study was conducted to investigate the effects of graded dietary inclusion levels
of betaine on ileal and total tract nutrient digestibilities and intestinal bacterial fermentation
characteristics in piglets. A total of 8 barrows (BW 7.9 kg) was fitted with simple T-cannulas at the
distal ileum. The animals were randomly allocated to 1 of the 4 assay diets with 2 pigs per treatment in
4 repeated measurement periods. The assay diets included a basal diet based on wheat, barley and
soybean meal alone, or supplemented with a liquid betaine product at dietary levels of 1.5, 3.0, or 6.0
g betaine kg–1
diet (as–fed). Ileal digestibilities of dry matter (DM) and neutral detergent fiber (NDF)
increased both quadratically and linearly (P<0.05), and ileal digestibility of glycine increased linearly
as dietary betaine level increased (P<0.05). Moreover, there were linear increases in the concentrations
of ileal D–lactic acid (P<0.05), indicating intensified intestinal bacterial activities as dietary betaine
level increased. At the fecal level, total tract crude protein (CP) digestibility increased quadratically
(P<0.05), and digestibility of amino acids (AA) tended to increase quadratically (P=0.06 to P=0.11),
except for proline (P>0.05), as dietary betaine level increased. The increased bacterial degradation of
CP and AA in the large intestine coincides with the linear increase (P<0.05) in fecal diaminopimelic
acid concentrations, indicating enhanced intestinal bacterial growth with increasing dietary betaine
levels. In most cases, there was a response in the variables that were measured up to 3.0 g betaine per
kg diet, whereas increasing the betaine level from 3.0 to 6.0 g betaine per kg diet had no additional
effect. It can be concluded that dietary betaine stimulates microbial fermentation of fiber in the small
intestine, leaving less fermentable fiber to reach the large intestine and therefore, increased microbial
degradation of protein in the large intestine may occur.
Keywords: piglets, betaine, digestibility, bacterial fermentation, microflor
Betaine, organic acids and inulin do not affect ileal and total tract nutrient digestibility or microbial fermentation in piglets
The study was conducted to investigate the effects of betaine alone or combined with organic acids and inulin on ileal and total tract nutrient digestibilities and intestinal microbial fermentation characteristics in piglets. In total, 24 four-week-old barrows with an average initial body weight of 6.7 kg were used in two consecutive experiments with 12 piglets each. Betaine, organic acids and inulin at a level of 0.2, 0.4 and 0.2%, respectively, or combinations of these supplements were added to the basal diet. The supplementation of betaine, organic acids and inulin or any of their combinations did not affect ileal and total tract nutrient digestibilities. The microbial fermentation products both at the ileal and faecal level were not affected by any of the treatments. In conclusion, combining betaine with organic acids and inulin did not have any associated effects on the variables that were measured
Dirac points with giant spin-orbit splitting in the electronic structure of two-dimensional transition-metal carbides
Two-dimensional (2D) materials, especially their most prominent member,
graphene, have greatly influenced many scientific areas. Moreover, they have
become a base for investigating the relativistic properties of condensed matter
within the emerging field of Dirac physics. This has ignited an intense search
for new materials where charge carriers behave as massless or massive Dirac
fermions. Here, we theoretically show the existence of Dirac electrons in a
series of 2D transition-metal carbides, known as MXenes. They possess twelve
conical crossings in the 1st Brillouin zone with giant spin-orbit splitting.
Our findings indicate that the 2D band structure of MXenes is protected against
external perturbations and preserved even in multilayer phases. These results,
together with the broad possibilities to engineer the properties of these
materials phases, make Dirac MXenes a potential candidate for studying and
developing novel Dirac-physics-based technologies.Comment: 4 figures and supplementar
Phase composition and transformations in magnetron-sputtered (Al,V)2O3 coatings
Coatings of (Al1-xVx)2O3, with x ranging from 0 to 1, were deposited by
pulsed DC reactive sputter deposition on Si(100) at a temperature of 550
{\deg}C. XRD showed three different crystal structures depending on V-metal
fraction in the coating: {\alpha}-V2O3 rhombohedral structure for 100 at.% V, a
defect spinel structure for the intermediate region, 63 - 42 at.% V. At lower
V-content, 18 and 7 at.%, a gamma-alumina-like solid solution was observed,
shifted to larger d-spacing compared to pure {\gamma}-Al2O3. The microstructure
changes from large columnar faceted grains for {\alpha}-V2O3 to smaller
equiaxed grains when lowering the vanadium content toward pure {\gamma}-Al2O3.
Annealing in air resulted in formation of V2O5 crystals on the surface of the
coating after annealing to 500 {\deg}C for 42 at.% V and 700 {\deg}C for 18
at.% V metal fraction respectively. The highest thermal stability was shown for
pure {\gamma}-Al2O3-coating, which transformed to {\alpha}-Al2O3 after
annealing to 1100{\deg} C. Highest hardness was observed for the Al-rich
oxides, ~24 GPa. The latter decreased with increasing V-content, larger than 7
at.% V metal fraction. The measured hardness after annealing in air decreased
in conjunction with the onset of further oxidation of the coatings
Primal-improv: Towards co-evolutionary musical improvisation
This paper describes a work in progress on co-evolving Artificial Neural Networks (ANNs) for music improvisation. Using this neuro-evolutionary approach the ANNs adapt to the changes in the human player's music as input, while still maintaining some of the structure of the musical piece previously evolved. The system is called PRIMAL-IMPROV and evolves modules that are composed of two ANNs, one controlling pitch and one controlling rhythm. The results of a quantitative study show that, by only introducing simple rules as fitness functions, the system is able to generate more interesting arrangements than ANNs evolved without a specific objective. The emerging and interesting musical patterns that are produced by the evolved ANNs hint at the promising potential of the system
Effect of graded levels of dietary betaine on ileal and total tract nutrient digestibilities and intestinal bacterial metabolites in piglets*
The study was conducted to investigate the effects of graded dietary
inclusion levels of betaine on ileal and total tract nutrient digestibilities
and intestinal bacterial metabolites in piglets. A total of eight barrows
with an average initial body weight of 7.9 kg were randomly allocated
to one of the four assay diets with two pigs per treatment in four
repeated measurement periods. The assay diets included a basal diet
based on wheat, barley and soybean meal alone, or supplemented with
a liquid betaine product at dietary levels of 1.5, 3.0, or 6.0 g betaine per
kilogram diet (as-fed). Ileal digestibilities of dry matter and neutral
detergent fibre increased both quadratically and linearly, and ileal
digestibility of glycine increased linearly as dietary betaine level
increased (p < 0.05). Furthermore, total tract digestibility of crude pro-
tein increased quadratically (p < 0.05) and total tract digestibilities of
most amino acids tended to increase quadratically (p = 0.06 to p = 0.11)
with increasing dietary betaine level. Moreover, there were linear
increases in the concentrations of most bacterial metabolites which were
significant p < 0.05 for ileal d-lactic acid and for faecal diaminopimelic
acid. The results demonstrate that dietary betaine supplementation stim-
ulates bacterial fermentation of fibre in the small intestine and bacterial
degradation of crude protein in the large intestine
WOODLAND POND SALAMANDER ABUNDANCE IN RELATION TO FOREST MANAGEMENT AND ENVIRONMENTAL CONDITIONS IN NORTHERN WISCONSIN
Woodland ponds are important landscape features that help sustain populations of amphibians that require this aquatic habitat for successful reproduction. Species abundance patterns often reflect site-specific differences in hydrology, physical characteristics, and surrounding vegetation. Large-scale processes such as changing land cover and environmental conditions are other potential drivers influencing amphibian populations in the Upper Midwest, but little information exists on the combined effects of these factors. We used Blue-spotted (Ambystoma laterale Hallowell) and Spotted Salamander (A. maculatum Shaw) monitoring data collected at the same woodland ponds thirteen years apart to determine if changing environmental conditions and vegetation cover in surrounding landscapes influenced salamander movement phenology and abundance. Four woodland ponds in northern Wisconsin were sampled for salamanders in April 1992-1994 and 2005-2007. While Bluespotted Salamanders were more abundant than Spotted Salamanders in all ponds, there was no change in the numbers of either species over the years. However, peak numbers of Blue-spotted Salamanders occurred 11.7 days earlier (range: 9-14 days) in the 2000s compared to the 1990s; Spotted Salamanders occurred 9.5 days earlier (range: 3 - 13 days). Air and water temperatures (April 13- 24) increased, on average, 4.8 oC and 3.7 oC, respectively, between the decades regardless of pond. There were no discernible changes in canopy openness in surrounding forests between decades that would have warmed the water sooner (i.e., more light penetration). Our finding that salamander breeding phenology can vary by roughly 10 days in Wisconsin contributes to growing evidence that amphibian populations have responded to changing climate conditions by shifting life-cycle events. Managers can use this information to adjust monitoring programs and forest management activities in the surrounding landscape to avoid vulnerable amphibian movement periods. Considering direct and indirect stressors such as changing habitat and environmental conditions simultaneously to better understand trends in space and time can help improve monitoring programs for this taxa, which is at major risk of continued declines
Electronic structure investigation of Ti3AlC2, Ti3SiC2, and Ti3GeC2 by soft-X-ray emission spectroscopy
The electronic structures of epitaxially grown films of Ti3AlC2, Ti3SiC2 and
Ti3GeC2 have been investigated by bulk-sensitive soft X-ray emission
spectroscopy. The measured high-resolution Ti L, C K, Al L, Si L and Ge M
emission spectra are compared with ab initio density-functional theory
including core-to-valence dipole matrix elements. A qualitative agreement
between experiment and theory is obtained. A weak covalent Ti-Al bond is
manifested by a pronounced shoulder in the Ti L-emission of Ti3AlC2. As Al is
replaced with Si or Ge, the shoulder disappears. For the buried Al and
Si-layers, strongly hybridized spectral shapes are detected in Ti3AlC2 and
Ti3SiC2, respectively. As a result of relaxation of the crystal structure and
the increased charge-transfer from Ti to C, the Ti-C bonding is strengthened.
The differences between the electronic structures are discussed in relation to
the bonding in the nanolaminates and the corresponding change of materials
properties.Comment: 15 pages, 8 figure
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