The Effect of Dietary Energy and Protein Levels on Production in Breeding Female Ostriches.

1. In a study spanning two breeding seasons, we assessed the effect of different dietary energy and protein levels on body mass, body condition, and egg production of female ostriches. 2. During the first breeding season, groups were given diets with energy concentrations of 8.5, 9.5 and 10.5 MJ/kg dry mass (DM) metabolisable energy (ME) and protein concentrations of 135, 150 and 165 g/kg. In the second breeding season, groups were given diets with ME of 7.5, 8.5 and 9.5 MJ/kg and protein contents of 105, 120 and 135 g/kg. 3. Body mass of birds on diets of 7.5 and 8.5 MJ/kg ME decreased significantly in the course of the breeding season compared with birds fed on diets with higher energy contents and body measurements decreased, suggesting a loss of body condition. 4. Females fed on diets containing only 7.5 MJ/kg ME produced significantly fewer eggs at significantly longer intervals, resulting in fewer chicks hatched. 5. There was no significant difference in egg mass, initial chick mass, chick survival to one month of age and body mass of chicks at one month. 6. Dietary protein concentrations had no effect on egg production, egg mass, hatchability, initial chick mass, chick survival or chick mass at one month old. 7. The female ostriches regained their original body mass during the 4-month rest period between breeding seasons, but significant differences in some parameters during the second breeding season suggest that they may not have fully recovered their body condition. 8. A dietary energy content of 7.5 MJ/kg proved to have an adverse effect on egg production by breeding female ostriches, and it may be concluded from this study that a diet containing 8.5MJ ME/kg DM and 105 g/kg protein should be regarded as the minimum that can be used for breeding female ostriches without compromising egg production

The Effect of Dietary Energy and Protein Levels on Body Condition and Production of Breeding Male Ostriches (Struthio cemelus domesticus).

In a study over two breeding seasons we assessed the effect of different energy and protein levels in the diet of male ostriches on their body weight, body condition and the fertility of the eggs produced by their females. During the first season, the birds were fed diets with energy levels of 8.5, 9.5 or 10.5 MJ metabolisable energy (ME)/kg dry matter (DM) and 13.5, 15.0 or 16.5% protein. Corresponding lysine concentrations were 6.5, 7.5 and 8.5 g/kg. In the second breeding season the groups were fed diets with energy levels of 7.5, 8.5 and 9.5 MJ ME/kg and protein levels of 10.5, 12.0 and 13.5%. Corresponding lysine concentrations were 4.9, 5.9 and 6.9 g/kg. During the first breeding season the weight of all birds increased, but the weight of those fed the 8.5 MJ ME/kg DM diet was significantly lower at the end of the season than that of birds fed diets containing 9.5 and 10.5 MJ ME/kg DM. During the second season the trend in the case of the 8.5 and 9.5 MJ ME/kg diets was the same as in the previous season, but a significant decrease in weight occurred in birds fed the 7.5 MJ ME/kg DM diet. A general loss in body condition occurred at all energy levels. In contrast, protein level in the diets had no significant effect on any parameters measured. There were no trends or significant differences in the production of fertile eggs with any of the experimental diets. We concluded from this study that levels of 8.5 MJ ME/kg DM and 10.5% protein in the diet of breeding male ostriches are sufficient if maintenance in weight is the main criteria for formulating rations

Ocular manifestations of children with sickle cell disease in Ibadan, Nigeria

Background: Children with sickle cell disease can present with ocular complaints. Regular eye examination can detect sight threatening conditions amenable to treatment. The aim of the study was to describe ocular manifestation of children with sickle cell disease attending the Pediatric Outpatient Department of the University College Hospital Ibadan.Methodology: Children 15 year and below diagnosed with sickle cell disease at the Pediatric Outpatient of the University College Hospital were examined in detail by the Ophthalmologist to document ocular findings.Results: One hundred and five (105) patients were examined. Mean age was 3.22 ± 2.49 years with a male to female ratio of 1.2: 1. Ninety children (85.7%) had Hemoglobin SS while HB SC had 15(14.3%). The commonest ocular finding was retinal vascular tortuosity in 15(14.3%). Other important findings were central retinal artery occlusion in 2 (1.9%) patients; black sunbursts pigmentation 2(1.9%); chorioretinal atrophy 3(2.8%), salmon patch retina hemorrhage 1(0.95%); retina holes1(0.95%) and retina coloboma1(0.95%). The only anterior segment finding was jaundice in all the patients. No conjunctiva vascular abnormalities were found.Conclusion: Retinal vascular tortuosity is the commonest ocular manifestation of children with sickle cell disease in Ibadan. Central retinal artery occlusion, a devastating condition is an emerging manifestation. Regular eye examination for sickle cell retinopathy in children less than 15 years of age is not recommended

Energy-Momentum Tensor of Particles Created in an Expanding Universe

We present a general formulation of the time-dependent initial value problem for a quantum scalar field of arbitrary mass and curvature coupling in a FRW cosmological model. We introduce an adiabatic number basis which has the virtue that the divergent parts of the quantum expectation value of the energy-momentum tensor are isolated in the vacuum piece of , and may be removed using adiabatic subtraction. The resulting renormalized is conserved, independent of the cutoff, and has a physically transparent, quasiclassical form in terms of the average number of created adiabatic `particles'. By analyzing the evolution of the adiabatic particle number in de Sitter spacetime we exhibit the time structure of the particle creation process, which can be understood in terms of the time at which different momentum scales enter the horizon. A numerical scheme to compute as a function of time with arbitrary adiabatic initial states (not necessarily de Sitter invariant) is described. For minimally coupled, massless fields, at late times the renormalized goes asymptotically to the de Sitter invariant state previously found by Allen and Folacci, and not to the zero mass limit of the Bunch-Davies vacuum. If the mass m and the curvature coupling xi differ from zero, but satisfy m^2+xi R=0, the energy density and pressure of the scalar field grow linearly in cosmic time demonstrating that, at least in this case, backreaction effects become significant and cannot be neglected in de Sitter spacetime.Comment: 28 pages, Revtex, 11 embedded .ps figure

Analytical approximation of the stress-energy tensor of a quantized scalar field in static spherically symmetric spacetimes

Analytical approximations for ${}$ and ${}$ of a quantized scalar field in static spherically symmetric spacetimes are obtained. The field is assumed to be both massive and massless, with an arbitrary coupling $\xi$ to the scalar curvature, and in a zero temperature vacuum state. The expressions for ${}$ and ${}$ are divided into low- and high-frequency parts. The contributions of the high-frequency modes to these quantities are calculated for an arbitrary quantum state. As an example, the low-frequency contributions to ${}$ and ${}$ are calculated in asymptotically flat spacetimes in a quantum state corresponding to the Minkowski vacuum (Boulware quantum state). The limits of the applicability of these approximations are discussed.Comment: revtex4, 17 pages; v2: three references adde

The Nuclear Sigma Term in the Skyrme Model: Pion-Nucleus Interaction

The nuclear sigma term is calculated including the nuclear matrix element of the derivative of the NN interaction with respect to the quark mass, $m_q\frac{\partial V_{NN}}{\partial m_q}$. The NN potential is evaluated in the skyrmion-skyrmion picture within the quantized product ansatz. The contribution of the NN potential to the nuclear sigma term provides repulsion to the pion-nucleus interaction. The strength of the s-wave pion-nucleus optical potential is estimated including such contribution. The results are consistent with the analysis of the experimental data.Comment: 16 pages (latex), 3 figures (eps), e-mail: [email protected] and [email protected]

Massless Minimally Coupled Fields in De Sitter Space: O(4)-Symmetric States Versus De Sitter Invariant Vacuum

The issue of de Sitter invariance for a massless minimally coupled scalar field is revisited. Formally, it is possible to construct a de Sitter invariant state for this case provided that the zero mode of the field is quantized properly. Here we take the point of view that this state is physically acceptable, in the sense that physical observables can be computed and have a reasonable interpretation. In particular, we use this vacuum to derive a new result: that the squared difference between the field at two points along a geodesic observer's space-time path grows linearly with the observer's proper time for a quantum state that does not break de Sitter invariance. Also, we use the Hadamard formalism to compute the renormalized expectation value of the energy momentum tensor, both in the O(4) invariant states introduced by Allen and Follaci, and in the de Sitter invariant vacuum. We find that the vacuum energy density in the O(4) invariant case is larger than in the de Sitter invariant case.Comment: TUTP-92-1, to appear in Phys. Rev.

Method to compute the stress-energy tensor for the massless spin 1/2 field in a general static spherically symmetric spacetime

A method for computing the stress-energy tensor for the quantized, massless, spin 1/2 field in a general static spherically symmetric spacetime is presented. The field can be in a zero temperature state or a non-zero temperature thermal state. An expression for the full renormalized stress-energy tensor is derived. It consists of a sum of two tensors both of which are conserved. One tensor is written in terms of the modes of the quantized field and has zero trace. In most cases it must be computed numerically. The other tensor does not explicitly depend on the modes and has a trace equal to the trace anomaly. It can be used as an analytic approximation for the stress-energy tensor and is equivalent to other approximations that have been made for the stress-energy tensor of the massless spin 1/2 field in static spherically symmetric spacetimes.Comment: 34 pages, no figure

EFFECTS OF CHANGE IN BODY POSTURE ON PLASMA AND SERUM ELECTROLYTES IN NORMAL SUBJECTS AND IN PRIMARY ALDOSTERONISM

We observed that change in body posture from the supine to the erect position in normal volunteers was associated with a rise in circulating potassium and a fall in sodium concentrations, irrespective of whether the electrolytes were measured in serum or plasma, or whether head-up tilt or ambulation was used. In patients with primary aldosteronism, the fall in serum sodium and rise in serum potassium with ambulation tended to obscure the characteristic electrolyte abnormalities of that syndrome. These changes in potassium and sodium could contribute to the rise in aldosterone secretion on orthostasis. The body posture of patients should be considered in the interpretation of plasma and serum electrolyte levels.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75439/1/j.1365-2265.1981.tb02972.x.pd