Two-scale modelling of Saponaria bellidifolia Sm. (Caryophyllaceae) abundance on limestone outcrops from its northern range periphery (Southeastern Carpathians)

We modelled the effect of habitat heterogeneity on the abundance of the submediterranean Saponaria bellidifolia, a red list species in Romania. The study was designed at two scales: 100 and 0.5 m². At larger scale, generalized additive models and canonical correspondence analysis were used to model the density of ramets, whereas at microscale, binomial logistic regression was employed to model the species’ occurrence. S. bellidifolia abundance responded sensitively to habitat type (classified as “grassy”, “rocky” and “scree”), rather than to microclimatic variables. At both scales, habitat type was the best predictor of ramet abundance, followed by slope and vegetation cover. At 0.5 m², soil depth was also a good predictor of species occurrence. The data revealed that screes are the most suitable habitats for hosting relatively large populations of this rare species, because of occasional natural disturbances and presumably lower interspecific competition.     

大鼠室旁核注射orexin-A对体重的影响

目的:探讨大鼠室旁核(PVN)注射orexin-A对体重的影响。方法:大鼠室旁核(PVN)微量注射orexin-A,用大脑置管埋管、组织化学染色等方法探讨PVN注射orexin-A对其体重的影响。结果:与安慰剂组大鼠相比,PVN注射orexin-A组大鼠体重明显减轻(P0.05),而orexin-A组和安慰剂组摄食量无明显差异(P0.05)。注射结束后6天,orexin-A处理大鼠的体重仍显著低于注射前(P0.05),而安慰剂组大鼠则比注射前显著增重(P0.05)。药物注射可显著降低机体脂肪,但并不特异存在于注射orexin-A或安慰剂的大鼠身上。Orexin-A组和安慰剂组大鼠的肌肉量和脂肪量均显著降低(P0.05),但注射orexin-A的大鼠降低更明显。与安慰剂组相比,orexin-A处理后的摄食转化率显著降低(P0.05)。结论:大鼠室旁核(PVN)注射orexin-A可通过增加活动量产生负能量平衡,引起体重减轻。     

Toxoplasma gondii: Electron microscopic study on the dye test reaction

When intact Toxoplasma trophozoites were stained with isotonic alkaline methylene blue solution, the organelles rich in nucleic acid, i.e., nucleus, free and membrane-bound ribosomes appeared as electron dense areas. When the parasites were incubated with the anti-Toxoplasma antibody and the accessory factor, swelling of the surface membrane occurred first, followed by destruction of the inner structures. In the dye test positive parasites, there were no definite organelles recognizable, as there were in the intact parasites. By the negative staining method, holes (defects) with dark central portions were observed on the surface of the parasites treated with the antibody and the accessory factor, the diameter of the holes measuring about 10–11 nm. These holes, which tended to occur in clusters, were each surrounded by a clear ring.     

Unbiased Estimation of Odds Ratio by Using Negative Binomial Plans

The use of the negative binomial distribution in both the numerator and denominator in prospective studies leads to an unbiased estimate of the odds ratio and an exact expression for its variance. Sample sizes that minimize the variance of odds ratio estimates are specified. The variance of the odds ratio estimate is shown to be close to the Cramér-Rao lower bound.     

The Negative Binomial Distribution of Order k and Some of Its Properties

The negative binomial distribution of order k is introduced and briefly studied. First it is shown that it is a proper probability distribution. Then its probability generating function, mean and variance are derived. Finally it is shown that the number of trials until the rth kth consecutive success (r ≧ 1, k ≧ 1) in independent trials with constant success probability p (0 < p < 1) is distributed as negative binomial distribution of order k. The present paper generalizes results of SHANE (1973), PHILIPPOU and MUWAFI (1982), and PHILIPPOU, GEORGHIOU and PHILIPPOU (1982).     

On a Mixed-Type Randomized Rule for Selecting Superior Binomial Models

We propose a new class of selection rules for selecting superior models from finite Binomial models. This new class of rules extends the classes of classical rules and shows its superiority to the classical selection rules by some Monte Carlo results. This new class of rules is easier and more flexible to apply than these known classical rules.     

On Analysis of Proportions in Tables with Spoiled Data

This paper discusses analysis of dispersion tests in tables with spoiled data, that is, where some cells are missing. BENNETT (1987) gave a method for estimating the missing cells in a two-way table and illustrated it with a simple example. This paper uses GLIM to estimate the models and indicates that the General Linear Model performs the computations without need to estimate the missing values. The binomial error model also may be used for this problem, and is the more natural approach to the problem.     

Discovery of 6-(pyrimidin-5-ylmethyl)quinoline-8-carboxamide negative allosteric modulators of metabotropic glutamate receptor subtype 5

Based on previous work that established fused heterocycles as viable alternatives for the picolinamide core of our lead series of mGlu₅ negative allosteric modulators (NAMs), we designed a novel series of 6-(pyrimidin-5-ylmethyl)quinoline-8-carboxamide mGlu₅ NAMs. These new quinoline derivatives also contained carbon linkers as replacements for the diaryl ether oxygen atom common to our previously published chemotypes. Compounds were evaluated in a cell-based functional mGlu₅ assay, and an exemplar analog 27 was >60-fold selective versus the other seven mGlu receptors. Selected compounds were also studied in metabolic stability assays in rat and human S9 hepatic fractions and exhibited a mixture of P450- and non-P450-mediated metabolism.     

An interpretation of aphid population development by statistical model

Shiyomi (1967a and b) proposed two models which describe the reproduction and the plant-to-plant movement of aphids. For the explanation of the whole process of development of population of aphids, the above two models were incorporated into a new model (called Model C). This model is superior in the following points to the negative binomial model:

1. Model C has 7 parameters and gives a fuller explanation compared with the negative binomial model which has 2 parameters.
2. Model C describes the structure of population at any stage of its development, while the negative binomial model describes that of a well developed stage of population.