Fecundity and longevity of houseflies after space flight

After 7 days of space flight house flies, Musca domestica, exhibited similar longevity, but a reduction in reproductive output as compared to earthbound controls. This reduction was not observed in later generations. These data suggest that space flight directly alters the rate of ovarian development, but that this effect is not genetically transmitted.     

Human epidermal growth factor receptor cDNA sequence and aberrant expression of the amplified gene in A431 epidermoid carcinoma cells

The complete 1,210-amino acid sequence of the human epidermal growth factor (EGF) receptor precursor, deduced from cDNA clones derived from placental and A431 carcinoma cells, reveals close similarity between the entire predicted v-erb-B mRNA oncogene product and the receptor transmembrane and cytoplasmic domains. A single transmembrane region of 23 amino acids separates the extracellular EGF binding and cytoplasmic domains. The receptor gene is amplified and apparently rearranged in A431 cells, generating a truncated 2.8-kilobase mRNA which encodes only the extracellular EGF binding domain.     

Further studies on neural tube defects caused by concanavalin A in early chick embryos

Summary Neural tube defects caused by concanavalin A in chick embryos are consequences of change in the cell surface of developing neuroepithelium.This study was supported in part by grants from the Rutgers University Research Council.     

Analysis of many short time sequences: Forecast improvements achieved by shrinkage

Credibility models in actuarial science deal with multiple short time series where each series represents claim amounts of different insurance groups. Commonly used credibility models imply shrinkage of group-specific estimates towards their average. In this paper we model the claim size yu in group i and at time t as the sum of three independent components: y_it = μ_r + δ_i + ?_it. The first component, μt = μ_t?1 + m_t, represents time-varying levels that are common to all groups. The second component, δ_i, represents random group offsets that are the same in all periods, and the third component represents independent measurement errors. In this paper we show how to obtain forecasts from this model and we discuss the nature of the forecasts, with particular emphasis on shrinkage. We also assess the forecast improvements that can be expected from such a model. Finally, we discuss an extension of the above model which also allows the group offsets to change over time. We assume that the offsets for different groups follow independent random walks.     

On estimation and prediction procedures for ar(1) models with power transformation

The power transformation of Box and Cox (1964) has been shown to be quite useful in short-term forecasting for the linear regression model with AR(1) dependence structure (see, for example, Lee and Lu, 1987, 1989). It is crucial to have good estimates of the power transformation and serial. correlation parameters, because they form the basis for estimating other parameters and predicting future observations. The prediction of future observations is the main focus of this paper. We propose to estimate these two parameters by minimizing the mean squared prediction errors. These estimates and the corresponding predictions compare favourably, via revs and simulated data, with those obtained by the maximum likelihood method. Similar results are also demonstrated in the repeated measurements setting.     

The effect of protein-energy malnutrition on appositional bone growth in the rat

Summary During protein-energy malnutrition appositional bone growth in the seventh caudal vertebra of the rat slows and finally ceases. During rehabilitation appositional growth begins agains and attains a rate in excess of that of the controls. This may account for alterations in skeletal proportions resulting from manutrition.Supported in part by National Research Council of Canada grant A4692.     

Fungal competition and mycotoxin production on corn

Summary Aflatoxin and secalonic acid D production in corn in laboratory and field by mixed cultures ofPencillium oxalicum andAspergillus flavus orA. parasiticus was lower than production by the pure cultures. However, mixed culture of these molds withFusarium spp. did not affect mycotoxin production.