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Understanding the direct and indirect mechanisms of xylanase action on starch digestion in broilers
The objective of the current study was to investigate the mechanisms of xylanase action in a maize-soya diet and its effect on starch digestion. A total of 60 broilers were divided into 6 treatment groups; a control group without xylanase, and five other groups supplemented with xylanase (Econase XT 25; 100 g/t) from 1, 2, 3, 4 or 5 weeks before slaughter. At the end of the experiment, digesta was collected from the gizzard, upper and lower small intestine, and both caeca. Digesta pH ranged from pH 2.2-4.4, 5.9-6.6, 6.7-7.8 and 5.7-7.3 in the gizzard, upper small intestine, lower small intestine, and both caeca, respectively, with no effect of xylanase (P > 0.05). Scanning Electron Microscope (SEM) images along with total starch measurements showed the progression of starch digestion through the tract. The SEM did not show any greater disruption to cell wall material with xylanase supplementation. This suggests that xylanase was not working directly on the cell wall and provides evidence for the hypothesis that xylanase works through an indirect mechanism. Peptide YY (PYY) concentration in the blood was higher during the first few weeks of supplementation, with longer periods of supplementation nulling this effect, implying that xylanase may be acting through a prebiotic mechanism. The RT-q PCR results revealed a numerical increase in glucose transporter (GLUT2 and SGLT1) expression at 2 and 3 weeks of xylanase supplementation, respectively, which might suggest a greater absorption capacity of birds. From these results, a potential mechanism of xylanase action in maize-based diets has been proposed
Quantum Criticality and Holographic Superconductors in M-theory
We present a consistent Kaluza-Klein truncation of D=11 supergravity on an
arbitrary seven-dimensional Sasaki-Einstein space (SE_7) to a D=4 theory
containing a metric, a gauge-field, a complex scalar field and a real scalar
field. We use this D=4 theory to construct various black hole solutions that
describe the thermodynamics of the d=3 CFTs dual to skew-whiffed AdS_4 X SE_7
solutions. We show that these CFTs have a rich phase diagram, including
holographic superconductivity with, generically, broken parity and time
reversal invariance. At zero temperature the superconducting solutions are
charged domain walls with a universal emergent conformal symmetry in the far
infrared.Comment: 52 pages, 16 figures, 3 appendices; minor changes, version to be
published in JHE
Domain Wall Holography for Finite Temperature Scaling Solutions
We investigate a class of near-extremal solutions of Einstein-Maxwell-scalar
theory with electric charge and power law scaling, dual to charged IR phases of
relativistic field theories at low temperature. These are exact solutions of
theories with domain wall vacua; hence, we use nonconformal holography to
relate the bulk and boundary theories. We numerically construct a global
interpolating solution between the IR charged solutions and the UV domain wall
vacua for arbitrary physical choices of Lagrangian parameters. By passing to a
conformal frame in which the domain wall metric becomes that of AdS, we uncover
a generalized scale invariance of the IR scaling solution, indicating a
connection to the physics of Lifshitz fixed points. Finally, guided by
effective field theoretic principles and the physics of nonconformal D-branes,
we argue for the applicability of domain wall holography even in theories with
AdS critical points, namely those theories for which a scalar potential is
dominated by a single exponential term over a large range
The influence of blood on the efficacy of intraperitoneally applied phospholipids for prevention of adhesions
<p>Abstract</p> <p>Background</p> <p>The formation of adhesions following abdominal surgery is a well known problem. In previous studies we demonstrated the efficacy and safety of intraperitoneally applied phospholipids in order to prevent adhesion formation. This study evaluates the influence of blood on the efficacy of intraperitoneally applied phospholipids for prevention of adhesions.</p> <p>Methods</p> <p>In 40 Chinchilla rabbits adhesions were induced by median laparotomy, standardized abrasion of the visceral and parietal peritoneum in defined areas of the ventral abdominal wall and the caecum. The animals were randomly divided into four groups. They received either phospholipids 3.0% or normal saline (NaCl 0,9%) (5 ml/kg body weight). In 50% of the rabbits we simulated intraperitoneal bleeding by administration of blood (1,5 ml/kg body weight). The other half served as control group. Ten days following the operation the animals were sacrificed and adhesion formation was assessed by computer aided planimetry and histopathologic examination.</p> <p>Results</p> <p>The median adhesion surface area in the NaCl-group (n = 9) amounted to 68,72 mm<sup>2</sup>, in the NaCl+Blood-group (n = 10) 147,68 mm<sup>2</sup>. In the Phospholipid (PhL)-group (n = 9) the median adhesion surface area measured 9,35 mm<sup>2</sup>, in the PhL+Blood-group (n = 9) 11,95 mm<sup>2</sup>. The phospholipid groups had a significantly smaller adhesion surface area (p < 0.05).</p> <p>Conclusion</p> <p>Again these results confirm the efficacy of phospholipids in the prevention of adhesions in comparison to NaCl (p = 0,04). We also demonstrated the adhesion preventing effect of phospholipids in the presence of intraperitoneal blood.</p
An instability of higher-dimensional rotating black holes
We present the first example of a linearized gravitational instability of an
asymptotically flat vacuum black hole. We study perturbations of a Myers-Perry
black hole with equal angular momenta in an odd number of dimensions. We find
no evidence of any instability in five or seven dimensions, but in nine
dimensions, for sufficiently rapid rotation, we find perturbations that grow
exponentially in time. The onset of instability is associated with the
appearance of time-independent perturbations which generically break all but
one of the rotational symmetries. This is interpreted as evidence for the
existence of a new 70-parameter family of black hole solutions with only a
single rotational symmetry. We also present results for the Gregory-Laflamme
instability of rotating black strings, demonstrating that rotation makes black
strings more unstable.Comment: 38 pages, 13 figure
Long-term complete responses after 131I-tositumomab therapy for relapsed or refractory indolent non-Hodgkin's lymphoma
We present the long-term results of 18 chemotherapy relapsed indolent (N=12) or transformed (N=6) NHL patients of a phase II anti-CD20 131I-tositumomab (Bexxar®) therapy study. The biphasic therapy included two injections of 450 mg unlabelled antibody combined with 131I-tositumomab once as dosimetric and once as therapeutic activity delivering 75 or 65 cGy whole-body radiation dose to patients with normal or reduced platelet counts, respectively. Two patients were not treated due to disease progression during dosimetry. The overall response rate was 81% in the 16 patients treated, including 50% CR/CRu and 31% PR. Median progression free survival of the 16 patients was 22.5 months. Median overall survival has not been reached after a median observation of 48 months. Median PFS of complete responders (CR/CRu) has not been reached and will be greater than 51 months. Short-term side effects were mainly haematological and transient. Among the relevant long-term side effects, one patient previously treated with CHOP chemotherapy died from secondary myelodysplasia. Four patients developed HAMA. In conclusion, 131I-tositumomab RIT demonstrated durable responses especially in those patients who achieved a complete response. Six of eight CR/CRu are ongoing after 46–70 months
Holography for Einstein-Maxwell-dilaton theories from generalized dimensional reduction
We show that a class of Einstein-Maxwell-Dilaton (EMD) theories are related
to higher dimensional AdS-Maxwell gravity via a dimensional reduction over
compact Einstein spaces combined with continuation in the dimension of the
compact space to non-integral values (`generalized dimensional reduction').
This relates (fairly complicated) black hole solutions of EMD theories to
simple black hole/brane solutions of AdS-Maxwell gravity and explains their
properties. The generalized dimensional reduction is used to infer the
holographic dictionary and the hydrodynamic behavior for this class of theories
from those of AdS. As a specific example, we analyze the case of a black brane
carrying a wave whose universal sector is described by gravity coupled to a
Maxwell field and two neutral scalars. At thermal equilibrium and finite
chemical potential the two operators dual to the bulk scalar fields acquire
expectation values characterizing the breaking of conformal and generalized
conformal invariance. We compute holographically the first order transport
coefficients (conductivity, shear and bulk viscosity) for this system.Comment: v2, Important additions: (1) discussion of the entropy current, (2)
postulated zeta/eta bound is generically violated. Some comments and
references added, typos corrected. 50 page
Three little pieces for computer and relativity
Numerical relativity has made big strides over the last decade. A number of
problems that have plagued the field for years have now been mostly solved.
This progress has transformed numerical relativity into a powerful tool to
explore fundamental problems in physics and astrophysics, and I present here
three representative examples. These "three little pieces" reflect a personal
choice and describe work that I am particularly familiar with. However, many
more examples could be made.Comment: 42 pages, 11 figures. Plenary talk at "Relativity and Gravitation:
100 Years after Einstein in Prague", June 25 - 29, 2012, Prague, Czech
Republic. To appear in the Proceedings (Edition Open Access). Collects
results appeared in journal articles [72,73, 122-124
Wilson loops in Five-Dimensional Super-Yang-Mills
We consider circular non-BPS Maldacena-Wilson loops in five-dimensional
supersymmetric Yang-Mills theory (d = 5 SYM) both as macroscopic strings in the
D4-brane geometry and directly in gauge theory. We find that in the Dp-brane
geometries for increasing p, p = 4 is the last value for which the radius of
the string worldsheet describing the Wilson loop is independent of the UV
cut-off. It is also the last value for which the area of the worldsheet can be
(at least partially) regularized by the standard Legendre transformation. The
asymptotics of the string worldsheet allow the remaining divergence in the
regularized area to be determined, and it is found to be logarithmic in the UV
cut-off. We also consider the M2-brane in AdS_7 x S^4 which is the M-theory
lift of the Wilson loop, and dual to a "Wilson surface" in the (2,0), d = 6
CFT. We find that it has exactly the same logarithmic divergence in its
regularized action. The origin of the divergence has been previously understood
in terms of a conformal anomaly for surface observables in the CFT. Turning to
the gauge theory, a similar picture is found in d = 5 SYM. The divergence and
its coefficient can be recovered for general smooth loops by summing the
leading divergences in the analytic continuation of dimensional regularization
of planar rainbow/ladder diagrams. These diagrams are finite in 5 - epsilon
dimensions. The interpretation is that the Wilson loop is renormalized by a
factor containing this leading divergence of six-dimensional origin, and also
subleading divergences, and that the remaining part of the Wilson loop
expectation value is a finite, scheme-dependent quantity. We substantiate this
claim by showing that the interacting diagrams at one loop are finite in our
regularization scheme in d = 5 dimensions, but not for d greater than or equal
to 6.Comment: 1+18 pages, 3 figures. v2 added a reference and made minor cosmetic
changes, JHEP version. v3 added generalization to arbitrary smooth, closed
contours, added references. v4 added references and clarified discussion
beneath eq. (23
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