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.     

The effects of acute and chronic morphine on regional distribution of cardiac output in brain

Summary Both acute and chronic administration of morphine resulted in an increase in the percent cardiac output received by brain. However, various brain regions were affected differently by the drug treatments. The greatest increases in percent cardiac output received after chronic administration of morphine occurred in pons and cerebellum, while the greatest increases after acute administration occurred in cortex and midbrain. The changes found are in contrast with earlier studies which suggest that morphine has no effect on cerebral blood flow.     

Exploration of the significance of values in the design of educational systems

In recent decades, there has been increased awareness of the need for systemic change in education. In systemic change, it is of the greatest importance that stakeholders examine and clarify their individual values and articulate shared values and state them clearly. This is necessary because values underlie visions, guide choices, decisions, and actions made in the course of design and, eventually, serve as practical tools in evaluating a system and its programs. This study explores the importance of articulating values in the design of educational systems. Given the importance of the clarification of values consented to by stakeholders and the lack of previous in-depth studies, the paper concludes that it is urgent to develop systemic and comprehensive value categories to aid in articulating core values and to serve as guidelines for applying these values in educational systems design.     

Dose response of gastric secretion,and electrolyte output in pylorus-ligated rats to insulin hypoglycemia

Zusammenfassung Die Insulinwirkung auf die Magensäuresekretion wurde in männlichen Sprague-Dawley Ratten untersucht, deren Pylorus 2 h vorher unterbunden war. Eine Dosis-Wirkungskurve wurde aufgestellt. Maximale Sekretion von Magensäure und Magensaft wurden durch s.c. Injektion von 4 Einheiten krystallinischen Zink-Insulins per 100 g Körpergewicht erzielt. Grössere Dosen von Insulin unterdrücken Säure- und Magensaftsekretion. Das Verhalten der Elektrolyte im Magensaft spricht sowohl für die Neutralisierungs-Verdünnungshypothese als auch für die Austausch-Diffusionshypothese zur Erklärung der Magensaftproduktion.     

Studies on the mechanisms of neurulation in the chick: The intracellular distribution of Ca++1

Summary Coated vesicles were found to accumulate Ca⁺⁺ in neuroepithelial cells and may play a role in regulating the contractile activities of apical microfilament bundles during uplifting of neural folds in the chick.This study was supported in part by grants from the Research Council and the Charles and Johanna Busch Memorial Fund of Rutgers University.     

Distribution of tunichrome and vanadium in sea squirt blood cells sorted by flow cytometry

Specialized blood cells of many tunicates accumulate high concentrations of vanadium and phenolic peptide pigments called tunichromes (TC). In order to determine whether V and TC reside in the same cells, Ascidia nigra and Ascidia ceratodes blood cell subpopulations were isolated by fluorescence-activated cell sorting (flow cytometry) and chemically analyzed. V was found in the spherical, green/grey signet ring cells, and to a lesser degree in the mulberry-shaped, yellow/green morula cells (MRs), whereas free TC was detected mainly in MRs.     

双丁酰环腺苷酸对人胃腺癌体外培养细胞DNA合成的影响

应用~3H-TdR光镜和电镜放射自显影观察表明,MGc80-3 细胞标记指数达31.51％,标记银粒集中于分裂间期的S期细胞核中,细胞核呈重标记状态,绝大多数标记银粒分布于细胞核常染色质区域,少数见于核孔附近的常染色质或核孔附近的细胞质中,核仁未见标记,显示细胞内 DNA合成十分活跃。但经 dBcAMP诱导后,标记指数则降至 4.35％,细胞核呈弱标记状态,电镜放射自显影则未在细胞核内见到标记银粒,表明其DNA合成受到明显抑制。这种变化是由于dBcAMP诱导胃癌细胞内cAMP水平提高而实现的,认为DNA合成抑制是导致MGc80-3细胞走向分化的一个重要原因,对于癌变细胞恶性表型逆转具有重要作用。