退化红壤不同植被恢复类型的土壤弹尾虫群落结构

以退化红壤的侵蚀裸地、旱生性草坡、稀疏针叶林、针叶林、针阔混交林5种植被恢复类型及常绿阔叶林（对照）为研究对象,对各类型植被的土壤弹尾虫群落进行了调查,共捕获弹尾虫2亚目7科23属,其中符跳属、类符跳属、小圆跳属等为优势类群.应用个体密度、类群数及多样性指数等指标,研究了植被类型对弹尾虫群落特征的影响.结果表明：各项指标以常绿阔叶林为最高,裸地最低,基本没有弹尾虫存在;旱生性草坡、稀疏针叶林、针叶林和针阔混交林4种植被恢复类型的土壤弹尾虫群落得到了一定恢复,但各类型之间土壤弹尾虫群落没有明显差异,均处于恢复的早期阶段;Bray-Curtis指数显示,侵蚀裸地与顶级常绿阔叶林的差异最大（0.99）,其它植被恢复类型与顶级常绿阔叶林的差异也较明显,但各植被恢复类型间弹尾虫群落的差异较小.     

退化红壤不同植被恢复类型的土壤弹尾虫群落结构

以退化红壤的侵蚀裸地、旱生性草坡、稀疏针叶林、针叶林、针阔混交林5种植被恢复类型及常绿阔叶林（对照）为研究对象,对各类型植被的土壤弹尾虫群落进行了调查,共捕获弹尾虫2亚目7科23属,其中符跳属、类符跳属、小圆跳属等为优势类群.应用个体密度、类群数及多样性指数等指标,研究了植被类型对弹尾虫群落特征的影响.结果表明：各项指标以常绿阔叶林为最高,裸地最低,基本没有弹尾虫存在;旱生性草坡、稀疏针叶林、针叶林和针阔混交林4种植被恢复类型的土壤弹尾虫群落得到了一定恢复,但各类型之间土壤弹尾虫群落没有明显差异,均处于恢复的早期阶段; Bray-Curtis指数显示,侵蚀裸地与顶级常绿阔叶林的差异最大（0.99）,其它植被恢复类型与顶级常绿阔叶林的差异也较明显,但各植被恢复类型间弹尾虫群落的差异较小.     

兰坪铅锌矿区植被恢复初期土壤种子库与地上植被关系的研究

尾矿废弃地是一种极端的生态系统,其植被恢复的研究将丰富传统的生态学理论。该研究通过野外植被调查与室内萌发实验相结合的方法,探讨了兰坪铅锌矿区植被恢复初期不同群落类型地上植被、土壤种子库及其相互关系。结果显示:（1）与对照群落（云南松林、高山栎灌丛）相比,尾矿区恢复期各群落（早熟禾人工草地、魁蒿群落、马桑灌丛）地上植被及土壤种子库的物种数、物种多样性均较低。（2）植被恢复时间较短的2个群落（魁蒿群落、人工草地）土壤种子库较地上植被物种多样性高。（3）尾矿区恢复期各群落地上植被及土壤种子库的优势种均主要由风播、种子繁殖的植物组成,菊科、禾本科占较大比例,这些植物在尾矿区植被恢复初期起重要作用。（4）尾矿区恢复期各群落土壤种子库与地上植被的物种相似性较高,各群落之间地上植被及土壤种子库的相似性则较低。研究表明,尾矿区恢复初期土壤种子库与地上植被紧密联系,群落改造方式、恢复时间对土壤种子库具有重要影响。     

北京市海淀区土壤节肢动物群落特征

掌握城市土壤节肢动物的群落结构和物种组成对保护城市物种多样性具有重要意义.用手拣法和干漏斗法对北京市土壤节肢动物进行调查,共得土壤节肢动物样本4 984个,隶属6纲16目,共36个类群,其中蜱螨目、蚁科和弹尾目是优势类群,分别占个体总数的32.60%,27.83%,26.91%.不同功能区土壤节肢动物群落特征不同,平均密度为公园＞机关单位＞校园＞工业区＞交通干线＞住宅区,丰富度为公园＞交通干线＞校园＞工业区＞机关单位＞住宅区.不同地表植被状况下,土壤节肢动物的平均密度、丰富度和多样性指数排序均为林地＞草地＞行道树＞裸地.另外土壤节肢动物的个体数和类群数随着土层的加深而减少.北京市土壤节肢动物群落组成与同地带森林生态系统土壤节肢动物群落组成基本相同.     

长春市不同土地利用生境土壤弹尾虫群落结构特征

对长春市郊区天然次生林、农田、防护林和市区公园绿地等典型土地利用生境进行土壤弹尾虫调查,研究土地利用差异对土壤弹尾虫群落结构的影响.结果表明,长春市土地利用差异对弹尾虫群落结构特征影响明显,地表凋落物移除和耕作活动是影响弹尾虫群落结构特征的主要因素,地表凋落物移除显著减少弹尾虫的个体数量和群落多样性,耕作活动影响弹尾虫个体数量在土体中的垂直分布;地表植物群落类型对土壤弹尾虫群落结构特征也有一定影响.     

广东双季稻区杂草地和稻田中捕食性节肢动物的群落动态

用吸虫器采样法,于1998年对广东省大沙镇双季稻区两块相邻的杂草地和稻田中捕食性节肢动物群落的结构进行了研究。在杂草地生境中共采集到73种捕食性节肢动物,其中55种为蜘蛛,18种为昆虫。3月21日,早稻田翻耕前,在杂草地中采集到33种捕食性节肢动物,密度为130头/m²。4月4日,水稻移栽1周后,在杂草地中采到29种捕食性节肢动物,密度为92头/m²;同期在稻田中采到12种捕食性节肢动物,密度为16.2头/m2。5月13日早稻成熟前期,在杂草地中只采到19种捕食性节肢动物,密度为28头/m²;而此期,在稻田中采到27种捕食性节肢动物,密度为53.2头/m²。在晚稻生长期,杂草地捕食性节肢动物与稻田捕食性节肢动物物种数和密度的变化与早稻生长期情况相似。杂草地与稻田两生境间的捕食性节肢动物群落的相似性系数大于0.5,由此可见,这两类生境中捕食性节肢动物的物种组成是非常相似的,具有较多的共有种。杂草地捕食性节肢动物群落可能是稻田捕食性节肢动物群落重建的重要种库之一。     

吉林中、西部平原区土壤弹尾虫群落结构的比较

2003年7月和9月对吉林省中、西部平原区天然次生林、农田、居民点园地、防护林和天然割草场等典型生境进行了土壤弹尾虫的调查,用Tullgren法提取弹尾虫,应用个体密度、类群数量、群落多样性、丰富度和均匀度等指数,研究土壤弹尾虫群落结构特征,了解土地利用差异对土壤弹尾虫群落结构的影响。共捕获土壤弹尾虫2亚目8科12属5 531头,优势类群为Onychiurus、Folsomia、Acanthocyrtus、Xenylla和Coloburella属, 占总捕获个体数的90.3%。弹尾虫类群空间分布的广狭与个体数量的多寡在吉林省中、西部平原区呈现出明显的一致性;中部平原区与西部平原区土壤弹尾虫群落组成差异主要体现在优势类群个体密度方面;生境类型明显影响弹尾虫个体密度分布,其中农田、居民点园地和防护林土壤弹尾虫个体密度较低,在不同土层间分布比较均匀,但生境差异对弹尾虫类群数的影响不明显;同时农业生产活动也降低了弹尾虫群落多样性。     

铜尾矿废弃地与相邻生境土壤种子库特征的比较

土壤种子库是植被群落的重要组成部分,其特征决定了群落的演替方向。对铜陵杨山冲尾矿库6个植被群落及相邻两处生境的土壤种子库进行了研究。结果表明,尾矿内各植被群落种子库的种子密度间存在较大差异,变化范围为57—593粒/m2,平均种子密度为370粒/m2,尾矿坝体和周围山体种子库种子密度分别为999和121粒/m2,各样地土壤中种子均主要集中在0—5 cm范围内。尾矿种子库与坝体种子库间的相似性指数大于其与周围山体种子库的相似性指数,但尾矿内各植被群落种子库间的相似性较差,相似性指数的变化范围为0.308—0.636。可见,群落微生境对土壤种子库的种子密度和物种组成产生了较大的影响。尾矿种子库种类与地上植被的平均相似指数为0.355,低于坝体种子库种类与地上植被相似性系数。3处样地土壤种子库的物种多样性、丰富度和均匀度指数均表现为坝体>尾矿>山体。尾矿种子库在农田土壤中萌发并正常生长的幼苗为16科44属53种,而在尾矿基质中仅为9科36属45种,均以禾本科、菊科和豆科植物萌发和生长状况较好,这3科构成了尾矿地上植被的主要类型。尾矿种子库在尾矿基质中萌发成活率为62.2%—91.2%,约为坝体和山体土壤种子库在尾矿基质中萌发成活率的2倍。说明,组成尾矿种子库的种子大部分已经适应了尾矿的极端恶劣环境或者其本身就是耐性极强的植物类型。     

吡虫啉对烟田节肢动物群落的影响研究

利用群落参数分析了吡虫啉对烟田节肢动物群落及其各亚群落的影响。结果表明,施药后对烟田节肢动物群落、害虫亚群落的物种数有一定的影响,对天敌昆虫和蜘蛛亚群落物种数的影响不明显。5月23日施药后至6月13日施药区(Ⅱ)和对照区节肢动物群落、害虫亚群落个体数均下降,下降程度施药区大于对照区。6月14日施药后施药区节肢动物群落、害虫亚群落个体数下降,对照区显著上升。两次施药对天敌昆虫和蜘蛛亚群落个体数的影响不明显,施药后一段时间内优势种烟蚜种群个体数量显著下降,使节肢动物群落和害虫亚群落优势集中性下降,多样性指数和稳定性增加。     

铁矿采矿迹地不同恢复年限的植被特征

1997-2011年利用覆盖客土、覆盖客土+生态植被毯措施对北京首云铁矿尾矿库进行植被恢复,本研究调查了不同恢复年限的植被特征,并与周边自然植被进行对比分析.结果表明:恢复植被以禾本科、豆科和菊科植物为主,占植物物种总数的58％;采用客土+生态植被毯恢复的植被多度、物种丰富度和Shannon指数均接近周边未扰动植被,高于仅覆盖客土恢复的植被;客土+生态植被毯恢复植被的地上和地下部分生物量显著高于仅覆盖客土的植被,与对照差异不显著;采用客土+生态植被毯措施恢复植被的枯落物生物量第6年达到对照水平.采矿迹地植被快速重建对北京市生态涵养发展区的潜在生态功能发挥具有重要的意义,为类似采矿迹地植被重建提供可借鉴的案例.     

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.