1,318 research outputs found
Conditioning Thermal Stability and Dose Effects of Commercially Available Phytase Preparations on Performance and Tibia Mineralization of Young Broiler Chickens
Phytases have become a vital part of broiler diets due to their ability to decrease feed cost and potential environmental pollution caused by the use of excessive phosphorus. The objective of the first study was to compare the effects of various inclusions of a Transgenic Phytase Corn (TPC) to a Granulated Bacteria Phytase (GBP) on 21-d broiler performance and tibia mineralization. Treatments varied in non-phytate phosphorus (Negative control (NC) = 0.2, positive control (PC) = 0.4, 0.3, and 0.35), phytase product (TPC or GBP), and phytase dose (500-3000 FTU/kg). A 2x2 factorial analysis was performed with the main effects phytase activity and phytase product. The inclusion of granulated bacterial phytase resulted in increased broiler performance and tibia mineralization compared to the inclusion of transgenic phytase corn. This may be attributed to variations in dispersion of enzyme within the diet or the general efficacy of the expressed enzyme. The inclusion of a commercial phytase at 3,000 FTU/kg increased broiler performance and tibia mineralization compared to inclusion at 500 FTU/kg. These results may be due to a greater reduction of phytate, alleviating anti-nutrient effects.;The objective of the second study was to evaluate the effects three commercial 6-phytase products with a phosphorus deficient diet subjected to increased steam conditioning temperatures on broiler performance and tibia mineralization. Treatments included a negative control, and a negative control with the addition of a Buttiauxella phytase expressed in Trichoderma reesei (B Trich), an E. coli phytase expressed in Pichia pastoris (E Pichia), or an E. coli phytase expressed in Trichoderma reesei (E Trich), steam conditioned at 82, 88, or 93°C, for a total of twelve treatments. Broiler performance and tibia mineralization were analyzed using a 4 x 3 factorial with the main effects of product and conditioning temperature. The commercial phytase products demonstrated differences in supporting the phosphorus requirement in broilers. Increasing conditioning temperatures had a detrimental effect on broiler performance and tibia mineralization. The increased conditioning temperatures may have decreased nutrient availability, denatured phytase products, or both of these events may have influenced the results
Fast determination of coarse grained cell anisotropy and size in epithelial tissue images using Fourier transform
Mechanical strain and stress play a major role in biological processes such
as wound healing or morphogenesis. To assess this role quantitatively, fixed or
live images of tissues are acquired at a cellular precision in large fields of
views. To exploit these data, large numbers of cells have to be analyzed to
extract cell shape anisotropy and cell size. Most frequently, this is performed
through detailed individual cell contour determination, using so-called
segmentation computer programs, complemented if necessary by manual detection
and error corrections. However, a coarse grained and faster technique can be
recommended in at least three situations. First, when detailed information on
individual cell contours is not required, for instance in studies which require
only coarse-grained average information on cell anisotropy. Second, as an
exploratory step to determine whether full segmentation can be potentially
useful. Third, when segmentation is too difficult, for instance due to poor
image quality or too large a cell number. We developed a user-friendly, Fourier
transform-based image analysis pipeline. It is fast (typically cells per
minute with a current laptop computer) and suitable for time, space or ensemble
averages. We validate it on one set of artificial images and on two sets of
fully segmented images, one from a Drosophila pupa and the other from a chicken
embryo; the pipeline results are robust. Perspectives include \textit{in vitro}
tissues, non-biological cellular patterns such as foams, and stacks.Comment: 13 pages; 9 figure
Concurrent 43 and 86 GHz Very Long Baseline Polarimetry of 3C273
We present sub-milliarcsecond resolution total intensity and linear
polarization VLBI images of 3C273, using concurrent 43 and 86 GHz data taken
with the Very Long Baseline Array in May 2002. The structure seen in the
innermost jet suggest that we have fortuitously caught the jet in the act of
changing direction. The polarization images confirm that the core is
unpolarized (fractional polarization m < 1 %) at 86 GHz, but also show well
ordered magnetic fields (m ~ 15 %) in the inner jet, at a projected distance of
2.3 pc from the core. In this strongly polarized region, the rotation measure
changes across the jet by 4.2 x 10^{4} rad m^{-2} over an angular width of
about 0.3 milliarcseconds. If the lack of polarization in the core is also
attributed to a Faraday screen, then a rotation measure dispersion > 5.2 x
10^{4} rad m^{-2} must be present in or in front of that region. These are
among the highest rotation measures reported so far in the nucleus of any
active galaxy or quasar, and must occur outside (but probably close to) the
radio emitting region. The transverse rotation measure gradient is in the same
sense as that observed by Asada et al and by Zavala and Taylor at greater core
distances. The magnitude of the transverse gradient decreases rapidly with
distance down the jet, and appears to be variable.Comment: 4 pages, LaTeX, 3 postscript figures, submitted to Astrophysical
Journal Letter
Discovery of two simultaneous non-harmonically related Quasi-Periodic Oscillations in the 2005 outburst of the black-hole binary GRO J1655-40
We studied the low-frequency quasi-periodic oscillations (LFQPOs) in the
black hole GRO J1655-40 during the 2005 outburst, using data from the Rossi
X-ray Timing Explorer. All LFQPOs could be identified as either type B or type
C using previously proposed classification schemes. In the soft state of the
outburst the type-C LFQPOs reached frequencies that are among the highest ever
seen for LFQPOs in black holes. At the peak of the outburst, in the
ultra-luminous state, the power spectrum showed two simultaneous,
non-harmonically related peaks which we identified as a type-B and a type-C
QPO. The simultaneous presence of a type-C and type-B QPO shows that at least
two of the three known LFQPO types are intrinsically different and likely the
result of distinct physical mechanisms. We also studied the properties of a
broad peaked noise component in the power spectra of the ultra-luminous state.
This noise component becomes more coherent with count rate and there are strong
suggestions that it evolves into a type-B QPO at the highest observed count
rates.Comment: 14 pages, 6 figures, 2 tables, accepted for publication in MNRA
How Narcissism Shapes Responses to Antisocial and Prosocial Behavior: Hypo-Responsiveness or Hyper-Responsiveness?
Narcissists have a relatively higher proclivity for displaying antisocial rather than prosocial behaviors, suggesting a comparatively higher tendency for unfavorably impacting societies. However, maintenance of social order also depends on appropriate responses to othersâ social behavior. Once we focus on narcissists as observers rather than actors, their impact on social functioning becomes less clear-cut. Theoretical arguments suggest that narcissists could be either hypo-responsive or hyper-responsive to othersâ social behavior. Across four studies, we examined narcissistsâ responsiveness to variations in othersâ antisocial and prosocial behaviors. Results showed that narcissists differentiated less between othersâ antisociality/prosociality, as reflected in their subsequent moral character evaluations (Studies 1â4) and reward and punishment (Studies 3 and 4). These results suggest that narcissists are hypo-responsive to othersâ social behaviors. Implications and directions for future research are discussed
A Comparative Study Of Cardiovascular Risk Factors Between Black And White Adolescent Males
The purpose of this descriptive study was to compare the existence of cardiovascular risk factors between black and white adolescent males within the 18 and 19 year age range. A total of 22 male subjects, 13 white and 9 black, completed a three-day diary of diet, exercise, and smoking activity entitled The Heart Health Profile. Subjects were also interviewed concerning family history of cardiovascular disease, and measurements of blood pressure, percentage of body fat, and body weight were obtained. The researcher hypothesized that when black and white adolescent males were compared, there would be no significant difference relative to seven cardiovascular risk factors: smoking, blood pressure, dietary cholesterol intake, percentage of body fat, percentage of body weight above maximum allowable weight, aerobic exercise, and family history of cardiovascular disease. When the two groups were compared using the t-test, the only hypothesis which was significant at the .0 5 level was family history of cardiovascular disease. Thus, hypothesis VII was rejected. Since there was no significant difference at the . 05 level between the two groups relative to the other six risk factors, the researcher failed to reject hypotheses I through VI
CTMC calculations of electron capture and ionization in collisions of multiply charged ions with elliptical Rydberg atoms
We have performed classical trajectory Monte Carlo (CTMC) studies of electron
capture and ionization in multiply charged (Q=8) ion-Rydberg atom collisions at
intermediate impact velocities. Impact parallel to the minor and to the major
axis, respectively, of the initial Kepler electron ellipse has been
investigated. The important role of the initial electron momentum distribution
found for singly charged ion impact is strongly disminished for higher
projectile charge, while the initial spatial distribution remains important for
all values of Q studied.Comment: 3 pages, 5 figure
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