Ghrelin receptors in human gastrointestinal tract during prenatal and early postnatal development

The aim of our study was to investigate the appearance, density and distribution of ghrelin cells and GHS-R1a and GHS-R1b in the human stomach and duodenum during prenatal and early postnatal development. We examined chromogranin-A and ghrelin cells in duodenum, and GHS-R1a and GHS-R1b expression in stomach and duodenum by immunohistochemistry in embryos, fetuses, and infants. Chromogranin-A and ghrelin cells were identified in the duodenum at weeks 10 and 11 of gestation. Ghrelin cells were detected individually or clustered within the base of duodenal crypts and villi during the first trimester, while they were presented separately within the basal and apical parts of crypts and villi during the second and third trimesters. Ghrelin cells were the most numerous during the first (∼11%) and third (∼10%) trimesters of gestation development. GHS-R1a and GHS-R1b were detected at 11 and 16 weeks of gestation, showed the highest level of expression in Brunner's gland and in lower parts of duodenal crypts and villi during the second trimester in antrum, and during the third trimester in corpus and duodenum. Our findings demonstrated for the first time abundant duodenal expression of ghrelin cells and ghrelin receptors during human prenatal development indicating a role of ghrelin in the regulation of growth and differentiation of human gastrointestinal tract.     

Distribution and accumulation of PVM and PVY,PVX in infected potato plants

The ability of PVM, PVY and PVX viruses and their progeny to distribute themselves and accumulate in primary infected potato plants by mono‐ and mixed infections is analysed. It is shown, that the transport and accumulation of virus in inoculated potato plants depends on variety resistance, combination of viruses and sequence of their application.     

A new species of Rhytidognathus (Carabidae,?Migadopini) from Argentina

The Migadopini are a small tribe of Carabidae with 47 species that occur in South America, Australia, and New Zealand, in the sub-Antarctic areas. In South America, most of the genera inhabit areas related to sub-Antartic Nothofagus forest except two monogeneric genera, the Ecuadorian genus Aquilex Moret and the Pampean genus Rhytidognathus Chaudoir. These two genera are geographically isolated from the remaining five South American genera. New material of Rhytidognathus from the northeast of Buenos Aires province and from Entre Ríos province permits establishing that the previous records of Rhytidognathus ovalis (Dejean) for Argentina were erroneous and that it belongs to a new species. Based on external morphological characters and from male and female genitalia we describe Rhytidognathus platensis as a new species. In this contribution we provide illustrations, keys, habitat characteristics and some biogeographic considerations on the distribution of Rhytidognathus.     

Ephelides are More Related to Pigmentary Constitutional Host Factors than Solar Lentigines

Ephelides and solar lentigines are benign pigmented spots, which are currently associated with an increased risk of skin cancer. These two pigmented spots are known to be discriminated by their clinical, histological, and electron microscopic characteristics, even though occasional misclassification can occur because of their similarity. It has also been questioned whether these spots are not one and the same. In this study, we have attempted to differentiate between these two pigmented spots with the use of a standardized protocol for clinical examinations on 272 healthy volunteers, paying particular consideration to their pigmentary and constitutional host factors. We found that solar lentigines 1) are more prevalent than ephelides, 2) increase in prevalence and number with higher age, and 3) are most prevalent on the trunk and occur more frequently in males than in females. A trend is also observed whereby ephelides 1) loose their prevalence with age, 2) become equally distributed on the face, arms, and trunk, and 3) occur more frequently in females. An intimate association of ephelides, but not solar lentigines, has been found with hair color and skin type. All of these findings are in agreement with most of those reported in the literature, supporting the view that ephelides and solar lentigines are different types of pigmented lesions.     

利用Ecopath模型评价鲢鳙放养对千岛湖生态系统的影响

“保水渔业”是中国控制"水华"暴发等生态灾变的措施之一，其结果存在较大的不确定性。在浙江省的新安江水库（千岛湖），"保水渔业"的实施带来了水质改善和渔业增产的双重效果。但在生态系统自组织层面，这种人工干预手段引起的生态系统结构化效应的研究，尚未真正展开。基于2008-2010年千岛湖的生态和渔业资源调查数据，应用EwE （V6.6）构建了2010年千岛湖生态系统的Ecopath模型，并将其与2004和2016年的模型进行对照，分析了千岛湖生态系统在鲢、鳙鱼放养下的变化。千岛湖生态系统在3个年份均为4个整合营养级，营养能流分布成典型的金字塔型，且营养流总量中流向碎屑的占比很大，营养级Ⅰ、Ⅱ的能量被利用得不够充分；除鲢、鳙鱼外大部分鱼类的生物量逐渐下降，浮游植物和碎屑的生物量增多；系统的初级生产力和规模得到了一定提升，但总体的能量转换效率有所降低。在一些和系统成熟度、复原力和稳定性密切相关的参数方面，总初级生产量/总呼吸量增加，Finn氏循环指数和Finn氏平均路径长度逐渐降低，3个年份的连接指数（CI）分别为0.223、0.219、0.263，系统杂食指数（SOI）分别为0.087、0.102和0.131。研究分析表明，长期的鲢、鳙鱼放养使千岛湖的食物网结构发生了较大的变动，生态系统的营养交互关系不够复杂，成熟度和稳定性有所下降。千岛湖作为一个由水库发展而来的淡水水体，食物网关系本身就较为简单。因此，未来需要避免过多的人为干扰，并基于生态学原理更系统地进行修复工作。     

Feeding Characteristics of Three Species of Intertidal Sea Anemones of the South Kuril Islands

We examined the content of the coelenteron of Oulactis orientalis, Cnidopus japonicus, and Aulactinia sp. (family Actiniidae) inhabiting the intertidal area of Shikotan and Kunashir Islands (South Kuril Islands). The feeding characteristics (food spectrum, the index of filling of the coelenteron, the index of food similarity of the species, occurrence frequency, the index of trophic importance, and the proportions of certain components in the food pellet) allowed us to determine that the examined species are euryphagous.     

On the Estimation of Heritability from Unbalanced Data

The distribution and moments, of ANOVA estimator of heritability are given under unbalanced random model. These expressions are used to investigate the effect of unbalancedness on the bias and variance/MSE of the estimator and also the validity of certain approximations for its variance, numerically. The computed results reveal that the unbalancedness increases both the bias and variance/MSE of the estimator and the Smith-approximation for the variance of the estimator provides better accuracy.     

Differential human impact and vegetation history in two adjacent Pyrenean valleys in the Ariège basin,southern France,from 3000 B.P. to the present

Detailed palynological studies in two adjoining French Pyrenean valleys, complemented by the study of archives, demonstrate that under similar climatic conditions, the forest history of each valley from the Bronze Age to present time was essentially determined by socio-economical constraints, possibly modified by natural characteristics such as topography. The studies show why the expansion of Fagus (beech) at c. 4000 B.P. was asynchronous on the northern slope of the Pyrenees and emphasize the effects of the human impact on the recent lowering of the tree-line.A contribution to the 8th IPC, Aix-en-Provence, 1992