沿海蝗区东亚飞蝗产卵选择的适应性

以沿海蝗区南大港水库为研究区域,通过2年野外调查旨在掌握东亚飞蝗Locustamigratoriamanilensis(Meyen)产卵场所的选择。结果表明,飞蝗产卵适宜的植被覆盖度、土壤含盐量和土壤5cm含水量分别为0~30%、0.09%~1.99%和10.0%~20.0%,当植被覆盖度>70%,土壤含水量>30%或含盐量>3%时,不再适合飞蝗产卵。土壤有机质和pH值不是影响飞蝗产卵选择的主要因素。与20世纪50年代的研究结果相比,飞蝗产卵时对土壤含水量和含盐量的耐受范围拓宽,对环境的适应能力增强。     

黄河三角洲盐生植被与土壤盐分的相关性研究

 本文在主要盐生植被类型研究的基础上,通过植物、土壤、水样品的化学测试,对黄河三角洲盐生植被与土壤盐分的相关性进行了定量的研究。结果表明：盐生植被的类型、空间分布、植株所含的化学成分、生物累积强度和演替等方面与土壤含盐量的关系极为密切。     

芨芨草群落土壤盐分特征

通过对内蒙古及青海9个样点芨芨草群落及其相邻地带性群落土壤电导率的研究,从区域大尺度及生境小尺度揭示了土壤盐分对芨芨草群落分布的影响,并基于土壤的盐分特征分析了芨芨草群落的植被属性。结果表明:在区域大尺度,芨芨草群落的分布与土壤盐分不存在直接的相关性,芨芨草既可以在低盐环境下形成群落,也可在盐分较高的环境下形成群落,是一个生态幅较宽的耐盐物种;而在相同地点的小尺度上,芨芨草群落的土壤含盐量总是比相邻地带性针茅群落的土壤含盐量高,地带性针茅群落的耐盐性不及芨芨草群落;青海地区大面积的芨芨草草原发育在含盐量较高的土壤环境,远高于相邻地带性针茅群落。土壤盐分特征分析结果表明,芨芨草群落表现出明显的非地带性植被特征,其分布与区域降水不存在直接的相关性。     

黄河三角洲垦利县夏季土壤水盐空间变异及土壤盐分微域特征

黄河三角洲作为我国重要的后备土地资源区,土壤盐渍化问题突出,切实掌握季节性土壤水盐状况及其微域特征是该区土壤盐渍化防控和土地资源高效利用的重要基础。选择黄河三角洲垦利县,通过野外调查实测与室内化验分析获取土壤水盐含量数据,利用统计分析、GIS空间插值、实地观测与数据分析对比等方法,分析了研究区夏季土壤水盐状况及其微域变异规律。结果显示:研究区夏季土壤水盐含量总体较高,含盐量以中度盐渍化为主,随着土层深度的增加含盐量呈上升趋势,且各层土壤含盐量呈显著正相关性;含盐量较高的地区主要分布在该区东北部和中东部,含盐量较低的地区主要分布在西南部和中部;土壤含盐量从大到小的植被类型依次为光板地→碱蓬→高粱→芦苇→茅草→水稻→棉花→玉米;土壤盐分微域变化特征明显,含盐量受距路边远近、不同耕作措施、地形部位、植被群落等因素影响较大,表现出微域规律性和复杂性。该研究基本摸清了研究区夏季时相的土壤水盐状况及其微域特征,为黄河三角洲农作物栽培管理及土壤资源可持续利用提供了科学依据。     

秦王川湿地柽柳分布与环境因子的关系

环境因子与植被分布的关系是生态学研究的重要内容,对揭示植物种群的形成机制和生态适应策略、预测植被的空间分布具有重要意义。为探究小尺度下干旱区湿地生境中环境因子对柽柳(Tamarix gansuensis H.Z.Zhang)空间分布的影响,在秦王川国家湿地保育区,基于遥感影像和数字高程模型,运用Maxent模型分析了海拔、坡度、坡向、坡位、离河流距离、土壤含水量、土壤含盐量等7个环境变量对柽柳空间分布的影响。结果表明:柽柳在秦王川国家湿地保育区内呈聚集分布,多分布在土壤含水量15%—30%、土壤导电率≤5 ms/cm、离河流18—70 m、海拔1890—1913 m、沟间地或沟坡地上;其空间分布主要受土壤含水量、含盐量和离河流距离3个环境变量的影响;海拔、坡度和离河流距离3个环境变量与土壤含水量、含盐量负相关(P0.05),坡位变量则与之相反。土壤水、盐含量等土壤因子是影响湿地植被分布格局形成的主要环境因子,水文因子和地形因子通过控制湿地土壤水、盐含量,改变局部环境条件,间接影响湿地植被的分布。     

基于多源遥感影像的盐碱地治理效果

将Landsat-8 OLI影像与Sentinel-2号影像结合,利用光合有效辐射比率（FPAR）,构建适用于MODIS植被总初级生产力（GPP）影像空间分辨率提高的逐层逐像元修正因子,实现内蒙古巴彦淖尔市赵贵圪旦组盐碱地农田改良前后的植被长势监测,同时结合不同深度土壤的含盐量数据,采用转移矩阵方法与热点分析方法分别分析了全局土壤含盐量变化与植被长势变化的局部差异。结果表明：（1）12-20号地块内土壤含盐量改良效果最明显,且研究区改良效果随土壤深度增加而逐渐降低。土壤深度0-20cm,盐土向中度盐土转入面积最大;土壤深度20-40cm,强度盐土向中度盐土转入面积最大;土壤深度40-60cm,强度盐土与盐土的转入面积大于转出面积,其他土壤的转入面积小于转出面积。（2）研究区内,GPP提升区域比降低区域面积约多60.36hm²,占研究区面积的42.88%;同时,对改良前植被GPP低值区域提高效果更明显。（3） GPP提升区域中热点区域集中分布在12-17、25-27、34号地块内,该区域改良效果显著;GPP降低区域中冷点区域集中分布在6、12-14、22-23、27-28、30-31号地块内,该区域改良效果差。     

黄河口湿地典型植物群落土壤水、盐入渗过程模拟

为探究积水条件、盐分条件对黄河三角洲河口湿地土壤水盐运移规律的影响,本研究采用实验室原位土柱实验,对芦苇、柽柳和盐地碱蓬3种典型河口湿地植被土壤的入渗过程及水盐重分布过程进行观测,并采用Hydrus-1D模型模拟水分入渗及重分布后的土壤剖面含水率、含盐量分布状况。结果表明：积水深度对土壤水分运移影响明显,不同积水深度条件下3种类型土壤的入渗速率均表现为先升高后骤降的变化趋势,并随入渗时间延长而不断衰减并趋于稳定;入渗实验结束后,0～30 cm土层含盐量基本与入渗水含盐量一致,在水盐运移末端(深度100 cm)趋近于土壤原始含盐量;水盐重分布后,剖面各层土壤含水率的差异减小,各层含盐量同入渗实验结束时含盐量相比基本保持不变;Hydrus-1D能很好地模拟土壤水盐入渗速率及土壤剖面的整体变化趋势,研究结果可为河口湿地水盐调控、湿地水文连通修复提供理论依据。     

基于林龄的滨海盐碱地杨树刺槐混交林土壤理化性质及草本植物多样性动态

以黄河三角洲滨海盐碱地不同林龄的杨树(Populus×Euramercana‘Neva’)、刺槐(Robinia pseucdoacacia)人工混交林及相应的纯林为研究对象,采用空间代时间的方法,研究了其不同林龄人工林林下植被特征与土壤理化性质变化。结果表明:(1)白茅(Imperata cylindrica)、猪毛菜(Salsola collina)、刺儿菜(Cirsium setosum)是滨海盐碱地人工林林下群落的优势种。(2)随着林分年龄(3年、7年、18年)的增加,杨树刺槐混交林及相应纯林Patrick指数及Margalef指数、Shannon-Wiener指数、Simpson指数及Pielou指数均表现出低-高-低的变化趋势,7年生时丰富度、草本多样性、均匀度最高。(3)杨树刺槐混交提高了林下草本物种组成及重要值,就纯林而言,刺槐林下植被物种多样性显著高于同龄杨树。(4)随着林龄的增大,杨树刺槐混交林及其纯林林下土壤p H值逐渐降低,杨树刺槐纯林土壤含盐量先增后减,杨树×刺槐混交林土壤含盐量依次递减;杨树刺槐混交林及其纯林林下土壤全磷含量呈先增加后减小趋势;杨树纯林及杨树×刺槐混交林全氮含量呈先减小后增加的趋势,刺槐纯林林下土壤全氮量呈连续增长的趋势;林龄间土壤p H、含盐量、全氮及全磷含量差异显著。(5)草本植物多样性相关指数与土壤含盐量呈极显著负相关,与土壤全磷量呈极显著正相关。     

滨海盐碱地刺槐(Robinia pseudoacacia)混交林土壤水盐动态

以固氮树种刺槐与绒毛白蜡、榆树、臭椿三树种的混交林及其纯林为研究对象,研究了刺槐与不同树种混交对土壤水分、盐分年动态变化的影响。研究结果表明：（1）刺槐与3个树种混交,刺槐臭椿混交林生长最好,均高于各自纯林。（2）混交林一定程度改善了土壤含水量及层次分布,土壤含水量整体趋势均表现出0～60 cm表层土中含水量高于各自纯林,而深层土壤含水量低的特点,只有8月份纯林和混交林的土壤含水量没有显著差别。不同树种在具体层次上略有差异;（3）混交林降低了土壤含盐量,改变了土壤盐分层次分布和年变化规律。不同月份间土壤含盐量随土壤深度、混交树种的变化而变化。深层土壤含盐量高,表层土壤含盐量低,混交林含盐量低于纯林且存在树种差异。混交林与纯林含盐量均雨季低,旱季高;但在某一具体月份各层次含盐量差别不大;不同土层含水量、含盐量与天然降水之间有明显的相关性,天然降水是混交林及纯林土壤水分的主要来源。     

滨海盐碱地刺槐(Robinia pseudoacacia)混交林土壤水盐动态

以固氮树种刺槐与绒毛白蜡、榆树、臭椿三树种的混交林及其纯林为研究对象,研究了刺槐与不同树种混交对土壤水分、盐分年动态变化的影响.研究结果表明:(1)刺槐与3个树种混交,刺槐臭椿混交林生长最好,均高于各自纯林.(2)混交林一定程度改善了土壤含水量及层次分布,土壤含水量整体趋势均表现出0～60 cm表层土中含水量高于各自纯林,而深层土壤含水量低的特点,只有8月份纯林和混交林的土壤含水量没有显著差别.不同树种在具体层次上略有差异;(3)混交林降低了土壤含盐量,改变了土壤盐分层次分布和年变化规律.不同月份间土壤含盐量随土壤深度、混交树种的变化而变化.深层土壤含盐量高,表层土壤含盐量低,混交林含盐量低于纯林且存在树种差异.混交林与纯林含盐量均雨季低,旱季高;但在某一具体月份各层次含盐量差别不大;不同土层含水量、含盐量与天然降水之间有明显的相关性,天然降水是混交林及纯林土壤水分的主要来源.     

Antibiotics in the treatment of wounds in the victims of the earthquake in the Armenian SSR

Purulent wounds in 88 victims of the Armenian earthquake with the syndrome of long-term squeezing were examined microbiologically and the experience with using antimicrobial drugs for their treatment was analyzed. In all the cases microbial associations were detected, coliform and nonfermenting gram-negative bacilli, enterococci, anaerobes and yeast-like fungi being isolated from 80, 20, 15 and 25 per cent of the patients respectively. 130 bacterial strains were studied in detail. 80 to 100 per cent of the bacterial isolates were resistant to the antibiotics routinely used in surgical practice, i.e. benzylpenicillin, tetracycline, levomycetin, kanamycin, cephalothin and cefazolin and highly sensitive to new antimicrobial drugs belonging to ureidopenicillins (mezlocillin), quinolones (ciprofloxacin) and cephalosporins of the 3rd generation (cefoperazone and ceftazidime). Retrospective estimation of the antibiotic therapy revealed its inadequacy in 55.7 per cent of the patients for the most part because of the isolates resistance. The 19 variants of the antibiotic use prescribed by the physicians mainly included penicillins, aminoglycosides and their combinations (in 67.2 per cent of the cases). The use of the highly efficient drugs of the groups of ureidopenicillins and quinolones was extremely rare which was likely due to lacking of information on the drugs.     

Changes in the size of the nucleoli of the Purkinje cells in the canine cerebellum in the postresuscitation period

The changes in the size of Purkinje cell (PC) nucleolus in the lateral and medial cerebellum zones were studied in dogs with different degree of neurologic status recovery after clinical death of various etiology and duration. PC always possess one nucleolus in the control and experimental groups. In the case of complete neurologic status recovery of animals the area of PC nucleolus increases in both zones studied, irrespective of the cause of clinical death. In the case of neurologic disorders the increase in PC nucleolus area is clearly expressed only in the medial zone of the cerebellum, being insignificant in the lateral zone. It is suggested that adaptive characteristics of PC are distinct in the two compared zones, which leads to greater PC vulnerability in the lateral zone during deep hypoxia.     

Histogenesis of the taste buds of the vallate papilla in the in the rat in the postnatal stages of development

The developing taste buds of vallate papillae were studied with electron microscope in rats during the first 7 days after birth. Two types of cells--light and dark--are identified in the taste buds of a one day old animal. The apical parts of dark cells are characterized by numerous dark granules. A distinguishing feature of light cells is the presence of synaptic contacts with afferent intragemmal nerves. On the 4th day of development on the top of the apical parts of the cell, a microvillar apparatus is seen to form, which does not yet communicate with the oral cavity. On the 7th day, basal cells appear in the taste buds. Some of these cells are seen mitotically dividing. The differentiated microvillar apparatus now communicates with oral cavity. The structure of the taste buds is getting similar to that in the adults. The structural and functional peculiarities of the developing taste buds are discussed in association with the period of ontogenesis under consideration.     

On the role of the pineal in thermoregulation in the pigeon

Diurnal rhythm in body temperature of pigeons subjected to different experimental conditions (pinealectomized, sham-operated, melatonin-implanted, cold-exposed) was studied under a 12 h light and 12 h dark regimen. The body temperature of pigeons during photophase was higher than that during scotophase in the normal as well as every treatment group studied. Pinealectomized pigeons showed higher body temperature in the photophase as well as scotophase, than that of the normal and sham-operated birds when examined 2 or 3 weeks following the post-surgical acclimatization to 25 or 3 degrees C. However, subcutaneous implantation of melatonin pellets into pinealectomized pigeons nullified or even reversed the hyperthermic effect of pinealectomy. Exposure of pigeons to--18 degrees C for 280 min during photophase as well as scotophase, produced a marked drop in body temperature in pinealectomized, sham-operated and normal pigeons. The pinealectomized pigeons exhibited a higher body temperature than that of the sham-operated and normal ones when exposed to--18 degrees C during the photophase, but not during the scotophase. It was concluded that while the pineal is not necessary for maintaining the daily thermal rhythm in the avian body, it has a thermoregulatory role, in that it prevents rise in body temperature in warm (25 degrees C) acclimatized and chronic cold (3 degrees C) exposed birds. In acute short-term cold (--18 degrees C) exposure however, the temperature regulatory role of the pineal was not effective during the scotophase.     

Frequency of the stages in the cycle of the seminiferous epithelium in the rat

This study determined the optimum number of tubules to be counted per testis cross section, and the number of animals per treatment group, when changes in stage frequencies in the cycle of the seminiferous epithelium are criteria for assessing effects of treatment on spermatogenesis. A data base of 9,672 observed and staged tubules was collected from testicular cross sections of 15 Sprague-Dawley rats. A significant variation between animals was found for the frequencies of Stages I, II, IV, VI, VIII, and XIII. Computer simulation was used to randomly select different combinations of animal and tubule numbers from the observed data. Stage frequency means from each simulation experiment were compared statistically to observed mean frequencies. A model that used data from all 14 stages was analyzed. The following conclusions were made: a) a minimum of 200 tubule cross sections/testis is recommended for estimating stage frequencies; b) for a fixed number of tubules scored, the number of animals sampled is more important than the number of tubules per animal in reducing variance; c) to detect a difference of 2 standard deviations from the mean with a 2% error rate and examining 200 tubules/testis, at least 12 animals must be used per group when assessing all 14 stages; d) when individual stages are examined using 10 animals per group, only Stage VII has 80% or greater power of test (alpha = 0.05) to detect a frequency difference; e) pooling stages into 3-4 groups is recommended to improve the power of detecting a treatment difference.