The effect of feeding high concentrations of cholecalciferol, phytase or the combination on broiler chicks and laying hens fed various concentrations of nonphytate phosphorus

Two broiler chick and one laying hen experiments were conducted to determine the effects of feeding high concentrations of cholecalciferol (D 3 ), phytase (PHY) or the combination on the respective bird group (broiler chick or laying hen) fed various concentrations of nonphytate phosphorus (nPP) on performance, tibia ash and total tract phosphorus retention. The first broiler experiment utilized a completely randomized design with a 5 × 3 factorial arrangement of treatments consisting of five dietary concentrations of nPP (0.20, 0.26, 0.33, 0.39 and 0.45%) and three of D3 (0, 7,500 and 15,000 IU/kg) fed from day 5 to 23. The second broiler experiment was arranged as a 4 × 2 × 2 factorial in a completely randomized design resulting in four dietary concentrations of nPP (0.15, 0.25, 0.35 and 0.45%), two of PHY (0 and 1,000 FTU/kg), and two of D3 (0 and 7,500 IU/kg) fed from day 4 to 18. Ross 308 broiler chicks were housed in battery cages in an environmentally controlled room with ad libitum access to feed and water. Body weight gain (BWG) and feed efficiency (FE) were calculated over the duration of the each broiler experiment. Tibia and excreta samples were collected at the end of each experiment to determine bone ash, expressed as total ash weight (AshW) and as a percentage of total tibia weight (AshP), and total tract phosphorus retention (TTPR). In experiment one, a main effect of nPP resulted in significant (P &le 0.05) increases in BWG, AshW, and AshP. There was a significant D3 × nPP interaction (P &le 0.05) for FE and TTPR. Supplementation of D3 improved FE up to 0.39% dietary nPP, while FE peaked at 0.26% dietary nPP and remained constant for the non&ndashsupplemented diets. A quadratic effect was observed in TTPR with supplemental D3 (at both levels), while inconsistent results in TTPR were noted for the non&ndashsupplemental diets. The results of experiment one suggest that although D3 increased the TTPR, this increased P retention had little effect on bird performance. In experiment two, there were main effects of PHY and nPP that resulted in significant (P &le 0.05) increases in BWG and FE. A significant (P &le 0.05) PHY × nPP interaction was observed in both AshW and AshP. As expected, PHY was more efficient in improving tibia ash at lower concentrations of nPP than with higher concentrations of nPP. A significant (P &le 0.05) three-way interaction among D3 × nPP × PHY occurred in TTPR due to a low P retention value of chicks fed the non&ndashsupplemented 0.45% dietary nPP. The addition of higher concentrations of D3 to boiler diets was able to effectively improve phosphorus retention in experiment one, but did not affect the performance of chicks in either. As expected, phytase supplementation had a positive effect on performance of chicks fed low nPP diets. A laying hen experiment was conducted to investigate the effects of feeding high concentrations of D3 and PHY to 240 42-week-old Hy-line W-36 laying hens fed no supplemental inorganic P on bird performance (egg production, feed intake, hen weight), egg shell quality, tibia ash and TTPR. The experiment consisted of five dietary treatments arranged in a randomized complete block design and was conducted over a 12 week period. Treatments consisted of a positive control diet formulated to contain 0.46% nPP, a negative control diet formulated to contain 0.12% nPP, the negative control diet supplemented with 300 FTU/kg of PHY, 7,500 IU/kg of D3 or the combination of both PHY and D3 . Hens were housed in high rise single tier cages in an environmentally controlled room with ad libitum access to feed and water. Egg production (EP), feed intake (FI), hen weight (HW), dry shell weight (DSW), shell thickness (ST), specific gravity (SG) were determined over the duration of the experiment. Tibia and excreta samples were collected at the end of the experiment to determine tibia ash, expressed as AshW and AshP, and TTPR. There was a significant (P \u3c 0.01) treatment effect for FI and HW, while a significant (P \u3c 0.02) treatment effect was observed over time for HW. Hens fed the positive control diet consumed 4 g more of feed per day than those fed the negative control, supplemental PHY or D3 diets, and 8 g more of feed per day than those fed the combination diet. Hens fed the positive control diet were overall significantly (P &le 0.05) heavier than those fed the supplemented PHY, D3 or the combination diets. Hens fed the negative control diet supplemented with D3 or the combination weighed less than those fed the positive control diet during the last six weeks of the experiment. A significant (P \u3c 0.0001) treatment effect was also seen in TTPR. The diet supplemented with D3 and the diet with both D3 and PHY supplementation had very low phosphorus retention when compared to the other three diets. Significant treatment effects were not observed for all other parameters tested (EP, ST, DSW, SG, AshW, AshP). Analysis of total phosphorus concentration of the diets noted total phosphorus concentrations were elevated than the formulated values. This might explain the lack of significant treatment effects on performance, egg quality, tibia ash and why phosphorus retention had a lower than expected value. The results from these experiments suggest that higher concentrations of dietary D3 may not be a suitable substitute for supplementation of inorganic phosphorus

Air pollution biomonitoring in an urban-industrial setting (Taranto, Italy) using Mediterranean plant species

This study presents the first report on the elemental composition of five Mediterranean plant species (Pinus pinaster, Eucalyptus camaldulensis, Nerium oleander, Olea europaea and Pittosporum heterophyllum) to trace industrial emissions in Taranto, Italy, a mixed-use industrial and urban setting. Potential metal sources include vehicular traffic, steel and cement plants, and a petrochemical refinery. Samples were collected from 29 sites covering the Tamburi-Lido Azzurro neighbourhood and the historical quarter Città Vecchia-Borgo. High concentrations of toxic metals were observed in all samples, with marked inter-species variability. Model based clustering identified two distinct groups, one dominated by pine needles with higher metal concentrations than the other group composed of the other four plant species. The contamination factor (CF) and pollution load index (PLI) indices which use background samples to standardise the level of pollution, were used to remove species effect allowing for direct site comparison. Spatial analysis of CF and PLI data identified pollution hotspots near industrial areas and major roads, with areas of little to no air pollution near green spaces. Statistical analysis of the CFs revealed the contribution of different sources to element emissions. Ni and Cr were primarily emitted from the steel plant and petrochemical refinery, while Fe and Al were associated with road traffic emissions, and geogenic elements Ca, Mg, K, and Na were linked to marine spray and Saharan dust. This study demonstrates that combining multiple plant species with pollution indices can be a cost-effective biomonitoring approach for assessing air pollution and creating a high-density spatial monitoring network

T-Branes and Monodromy

We introduce T-branes, or "triangular branes," which are novel non-abelian bound states of branes characterized by the condition that on some loci, their matrix of normal deformations, or Higgs field, is upper triangular. These configurations refine the notion of monodromic branes which have recently played a key role in F-theory phenomenology. We show how localized matter living on complex codimension one subspaces emerge, and explain how to compute their Yukawa couplings, which are localized in complex codimension two. Not only do T-branes clarify what is meant by brane monodromy, they also open up a vast array of new possibilities both for phenomenological constructions and for purely theoretical applications. We show that for a general T-brane, the eigenvalues of the Higgs field can fail to capture the spectrum of localized modes. In particular, this provides a method for evading some constraints on F-theory GUTs which have assumed that the spectral equation for the Higgs field completely determines a local model.Comment: 110 pages, 5 figure

On Global Flipped SU(5) GUTs in F-theory

We construct an SU(4) spectral divisor and its factorization of types (3,1) and (2,2) based on the construction proposed in [1]. We calculate the chiral spectra of flipped SU(5) GUTs by using the spectral divisor construction. The results agree with those from the analysis of semi-local spectral covers. Our computations provide an example for the validity of the spectral divisor construction and suggest that the standard heterotic formulae are applicable to the case of F-theory on an elliptically fibered Calabi-Yau fourfold with no heterotic dual.Comment: 45 pages, 12 tables, 1 figure; typos corrected, footnotes added, and a reference adde

The Structure of n-Point One-Loop Open Superstring Amplitudes

In this article we present the worldsheet integrand for one-loop amplitudes in maximally supersymmetric superstring theory involving any number n of massless open string states. The polarization dependence is organized into the same BRST invariant kinematic combinations which also govern the leading string correction to tree level amplitudes. The dimensions of the bases for both the kinematics and the associated worldsheet integrals is found to be the unsigned Stirling number S_3^{n-1} of first kind. We explain why the same combinatorial structures govern on the one hand finite one-loop amplitudes of equal helicity states in pure Yang Mills theory and on the other hand the color tensors at quadratic alpha prime order of the color dressed tree amplitude.Comment: 75 pp, 8 figs, harvmac TeX, v2: published versio

Acute aortic dissection in a young patient without Marfan fibrillinopathy: a case report

This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

The level set method for the two-sided eigenproblem

We consider the max-plus analogue of the eigenproblem for matrix pencils Ax=lambda Bx. We show that the spectrum of (A,B) (i.e., the set of possible values of lambda), which is a finite union of intervals, can be computed in pseudo-polynomial number of operations, by a (pseudo-polynomial) number of calls to an oracle that computes the value of a mean payoff game. The proof relies on the introduction of a spectral function, which we interpret in terms of the least Chebyshev distance between Ax and lambda Bx. The spectrum is obtained as the zero level set of this function.Comment: 34 pages, 4 figures. Changes with respect to the previous version: we explain relation to mean-payoff games and discrete event systems, and show that the reconstruction of spectrum is pseudopolynomia