The structure of the upper atmosphere of mars: In situ accelerometer measurements from mars global surveyor

The Mars Global Surveyor (MGS) z-axis accelerometer has obtained over 200 vertical structures of thermospheric density, temperature, and pressure, ranging from 110 to 170 kilometers, compared to only three previous such vertical structures. In November 1997, a regional dust storm in the Southern Hemisphere triggered an unexpectedly large thermospheric response at mid-northern latitudes, increasing the altitude of thermospheric pressure surfaces there by as much as 8 kilometers and indicating a strong global thermospheric response to a regional dust storm. Throughout the MGS mission, thermospheric density bulges have been detected on opposite sides of the planet near 90 degreesE and 90 degreesW, in the vicinity of maximum terrain heights. This wave 2 pattern may be caused by topographically-forced planetary waves propagating up from the lower atmosphere.     

Effects of translocation on survival and growth of freshwater mussels within a West Gulf Coastal Plain river system

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Modified assay for true and apparent metabolisable energy based on tube feeding

1. To improve the accuracy with which true metabolisable energy (TME) values of feedingstuffs are determined, a modification to the assay based on tube-feeding is proposed. 2. To ensure that the gastrointestinal tracts of the experimental birds are as empty as possible at the start of the assay it is recommended that the normal food is withdrawn 48 h before tube-feeding. 3. In order to partly alleviate the effects of starvation, all birds are given two doses of 25 g glucose (as an aqueous solution) about 40 and 16 h before tube-feeding. Birds, from which endogenous energy losses are to be derived, are fed 50 g glucose rather than given no food. 4. All birds are given 50 ml water by tube about 32 h after feeding to overcome any effects induced by low water intake. 5. A comparison of the two procedures with 8 feedingstuffs showed that the mean coefficient of variation was reduced from 5.5% to 1.5% for TME and from 4.7% to 1.8% for TME.     

Estimation of genetic trend in a selected population with and without the use of a control population

Data from a selection experiment conducted with sheep at Massey University, New Zealand, were analyzed to obtain an evaluation of selection response. Selection was for heavy 14-mo greasy fleece weight. Approximately seven generations of selection were represented in the data. Three estimates of genetic superiority of the selected line to the control line were obtained. All three estimates were obtained from a mixed model evaluation using the individual animal model for predicting breeding values from own and relatives' records. The estimators were 1) deviation of selected line predicted yearly phenotypes from control line predicted yearly phenotypes, 2) deviation of the predicted yearly phenotype for the selected line from the year estimate in the control line and 3) the mean yearly breeding value from the analysis of the selected line only. The realized heritability using the first approach was .20. However, the control line was found to have a slight positive drift; hence, this estimate was biased downward. Using Approach 2, accounting for drift, the realized heritability was .23. The same realized heritability, .23, was obtained from an analysis of the selected line ignoring the control (Approach 3), when a prior heritability of .30 was assumed for the mixed model evaluation. The estimate of genetic trend from predicted breeding values in the latter approach is, however, quite dependent on the assumed heritability.     

Growth performance of broilers fed on diets containing processed poultry wastes

1. Broilers were grown on diets containing processed poultry wastes: dehydrated broiler litter, with (DBLA) or without (DBLN) arsenical residues, “in‐house” dried waste (IHDW) and dehydrated layer waste (DLW), all from commercial poultry houses.

2. Wastes were included at 100 g/kg in starter and finisher diets given, in most cases, from 0 to 8 weeks. In formulation the contents of true protein and of experimentally‐determined metabolisable energy values were used to ensure nutritional balance.

3. Body weight at 8 weeks with inclusion of wastes was equivalent to control (DLW) or increased (DBLA, DBLN). The gain: food ratio was reduced by the two layer wastes because of increased food consumption. Litter moisture was increased by the feeding of wastes.     

Effects of food regulation during the growing and laying stages on the productivity of broiler breeders

1. From 1 to 22 weeks of age 720 Ross 1 parent stock pullets were given regulated amounts of food to achieve 90, 100 or 110% of a target weight (R90, R100 or R110, respectively) while from 23 to 64 weeks of age they were fed 80 or 100% of a set allowance (L80 or L100, respectively). One hundred and fifty Ross 1 parent stock males were on the R110 treatment and then either the L80 or L100 during breeding.

2. Mean number of settable (> 53 g) eggs per hen housed was 131, 131 and 135 and mean number of chicks hatched per hen housed was 108, 101 and 101, respectively, for the R90, R100 and R110 treatments. These differences were not statistically significant.

3. Mean number of settable eggs per hen housed was 116 and 148 and mean number of chicks hatched per hen housed was 94 and 112, respectively, for the L80 and L100 treatments (P<0.001).

4. Fertility and hatchability were improved but uniformity of the birds was decreased by restricting food intake.