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91.
The eggshell of Reeve's pheasant (Syrmaticus reevesii) collected from the Dongzhai National Nature Reserve in Henan Province,China was studied.By using scanning electron microscopy and inductively coupled plasma (ICP) spectrometry,the ultrastructure and elemental composition of the eggshell was determined.The study showed that the average thickness of the surface layer of crystals,the palisade and cone layer,and the eggshell membrane were 20.8,220.8 and 62.5 larn,respectively,accounting for 6.8%,72.6% and 20.6% of the total thickness of the eggshell.There were many vesicular holes in the palisade layer with an average diameter of 0.32±0.08 μm(n = 30).The function of these holes might be significant to air exchange.The shape of the eggshell pore on the surface layer of crystals is round or elliptical.The fracture surface of the pore is funnel-shaped.Some granules filled the upper part of the eggshell pores.The content of 21 elements in the eggshell of wild and captive Reeve's pheasants was compared and presented.It indicated that among the elements that made up the eggshell of the wild pheasant,the content of Ca,Mg,P and S was much higher,ω> 1 mg/g,with ω (Ca) being higher than 40% of the eggshell.The contents of Na,Si,Sr,K and A1 were ω = 0.1-1 mg/g,while Fe,Zn,Pb,Mn,Cu,V and Ti had lower concentrations (ω = 1-100 μg/g).The ω ofNi,Cr,Co,Se,Cd were lower than 1 μg/g.The elemental composition in the eggshell of the captive Reeve's pheasant kept in the Dongzhai National Natural Reserve was significantly different from that of the wild species,with a difference of over 20% on S,Cu,Fe,AI,Mn,Si,Sr,Se and Cr.The lower intake of Fe,Mn,Si and Sr on the one hand and the higher intake of S,Cu,Al and Cr on the other hand might be responsible for the low fertility of captive Reeve's pheasants in the Dongzhai National Nature Reserve.In order to ensure that the pheasants are receiving the proper amount of nutrition and to improve their breeding success,the amount of certain elements in the food should be adjusted.  相似文献   
92.
凝结芽胞杆菌(TBC169)片治疗便秘的实验研究和临床疗效   总被引:3,自引:1,他引:2  
目的观察凝结芽胞杆菌片(BC1)对便秘的药理作用和I临床疗效。方法昆明种雄性小鼠随机分为6组(每组10只)。BC1片(3个剂量)和BCz片治疗组小鼠口服BC。片和BC2片,空白对照组小鼠和模型对照组小鼠口服自来水,每天1次,共7d。之后,两治疗组和模型对照组小鼠在禁食12h后.均口服复方地芬诺酯(CDX)片,引发便秘。成人慢性便秘38例患者随机分为治疗组(20例)和对照组(18例),分别口服BC1片和金双歧片(BG),每天3次,共14~21d。结果BC1片能明显地减少便秘小鼠的首次排便时间(P〈0.05)和显著地增加大便粒数及重量(P〈0.05)。在临床试验中,治疗成人慢性便秘,BC1片的治愈率为45%,总有效率为70%,而相对的BG片分别为44%和72%,两药均未见不良反应或副作用。结论BC1片对小鼠实验性便秘和成人慢性便秘均有明显的治疗作用,在临床试验中未见不良反应或副作用。  相似文献   
93.
Cacopsylla melanoneura is a univoltine psyllid vector of ‘Candidatus Phytoplasma mali’, the etiological agent of apple proliferation (AP), a severe disease in European apple orchards. The influence of ‘Ca. P. mali’ on the fitness of C. melanoneura was studied. In the spring of 2007, male-female pairs of field-collected adults were exposed to ‘Ca. P. mali’-infected or healthy ‘Golden Delicious’ apple shoots. Exposure to these diseased shoots did not affect the life span of the adult psyllids. However, significantly fewer eggs were laid on the diseased shoots. Furthermore, fewer of the eggs that were laid on the infected plants hatched. Data suggest a detrimental effect of AP phytoplasma on the fitness of C. melanoneura.  相似文献   
94.
From April to July 2003 and 2004, we surveyed the nest-site selection of the White Eared pheasant (Crossoptilon crossoptilon) in the Zhujie Monastery and in the mountain facing it in Sichuan Province, China. In this paper, we studied the nest characteristics and the clutch size of the pheasant. Habitat sampling method was used to determine the variables that might affect the nest-site selection of the White Eared pheasant. Chi-square test was used to identify which habitat type was likely to be preferred by the bird. Independent-samples t test and Mann-Whitney U test were used to find which variables were important for the birds’ nest-site selection. A total of 13 nests were found. Oak shrub was greatly preferred as nest sites (84.62%). Nests under a rock wall (7.69%) and a fallen tree (7.69%) were also found. The average clutch size of a White Eared pheasant is 7.33±0.54 (range, 5–11; n=12). Laying period was between April 27 and May 21. In the Zhujie area, 1 nest was in the forest and 11 nests were in oak shrubs. The species preferred oak shrub as its nesting habitat (χ 2=8.333, df=1, P<0.05). The bird was more likely to place its nest in sites with a high coverage, i.e. 0.5, 1, and 2 m above the ground (independent-samples t test, P<0.05), and with a large shrub diameter (Mann-Whitney U test, P<0.05). The species are more likely to prefer sites with plant cover, shrub cover (independent-samples t test, P<0.05), and shrub height (Mann-Whitney U test, P<0.05) in a relatively small range. Translated from Journal of Beijing Normal University (Natural Science), 2005, 41(2) (in Chinese)  相似文献   
95.
PurposeThis study performed the accurate measurements of beam profiles with a new rigid board, which was consistent with the supplied reference beam profiles (RBPs) for clinical Halcyon model.MethodsPercentage depth doses (PDDs), lateral and diagonal dose profiles were measured and compared with RBPs. A water tank was set on the rigid board bridged Halcyon bore without sagging and source-to-surface distance was 90.0 cm. Field sizes were from 2.0 to 28.0 cm squares and depths of lateral and diagonal dose profiles were 1.3, 5.0, 10.0, and 20.0 cm. For the PDD, the depth of maximum dose (dmax), PDD value at depth of 10.0 cm (PDD10), and absolute dose difference (DD) between RBP and measured beam profiles (MBP) were evaluated. For lateral and diagonal dose profiles, DDs for the whole and divided areas (central, shoulder, and extended areas) defined by third derivative, and distance-to-agreement (DTA) in the penumbra area were evaluated.ResultsFor PDDs, the differences of dmax and PDD10 and DD beyond the dmax were within 1.0 mm, 0.3%, and 1.0%, respectively. For lateral and diagonal dose profiles, the DDs reached approximately 5.0% in the whole area because of penumbra area, while the DDs in the central, shoulder, and extended areas were within 1.0%, 2.0%, and 1.0%, respectively. The DTAs in the penumbra area were within 0.8 mm.ConclusionsThe supplied RBPs can be used clinically owing to the good agreement with the accurate MBPs with rigid board.  相似文献   
96.
Synthetic genomics-driven dematerialization of genetic resources facilitates flexible hypothesis testing and rapid product development. Biological sequences have compositional biases, which, I reasoned, could be exploited for engineering of enhanced synthetic genomics systems. In proof-of-concept assays reported herein, the abundance of random oligonucleotides in viral genomic components was analyzed and used for the rational design of a synthetic genomics framework with plant virome capacity (SynViP). Type IIS endonucleases with low abundance in the plant virome, as well as Golden Gate and No See'm principles were combined with DNA chemical synthesis for seamless viral clone assembly by one-step digestion-ligation. The framework described does not require subcloning steps, is insensitive to insert terminal sequences, and was used with linear and circular DNA molecules. Based on a digital template, DNA fragments were chemically synthesized and assembled by one-step cloning to yield a scar-free infectious clone of a plant virus suitable for Agrobacterium-mediated delivery. SynViP allowed rescue of a genuine virus without biological material, and has the potential to greatly accelerate biological characterization and engineering of plant viruses as well as derived biotechnological tools. Finally, computational identification of compositional biases in biological sequences might become a common standard to aid scalable biosystems design and engineering.  相似文献   
97.
Golden‐cheeked Warblers (Setophaga chrysoparia) are endangered songbirds that breed exclusively in the Ashe juniper (Juniperus ashei) and oak (Quercus spp.) woodlands of central Texas. Despite being the focus of numerous studies, we still know little about the size of the range‐wide breeding population and how density varies across the spectrum of juniper co‐dominated woodlands. Models that have been tested and shown to be accurate are needed to help develop management and conservation guidelines. We evaluated the accuracy and bias of density estimates from binomial mixture models, the dependent double‐observer method, and distance sampling by comparing them to actual densities determined by intensive territory monitoring on plots in the Balcones Canyonlands Preserve, Austin, Texas. We found that the binomial mixture models consistently overestimated density by 1.1–3.2 times (actual density = 0.07–0.46 males/ha), and the other two models overestimated by 1.1–29.8 times at low density and underestimated by 0.5–0.9 times at high density plots (actual density = 0.01–0.46 males/ha). The magnitude of error for all models was greatest at sites with few or no birds (<0.15 males/ha), with model performance improving as actual density increased. These non‐linear relationships indicate a lack of sensitivity with respect to true changes in density. Until systematic evaluation demonstrates that models such as those we tested provide accurate and unbiased density estimates for a given species over space and time, we recommend additional field tests to validate model‐based estimates. Continued model validation and refinement of point‐count methods are needed until accurate estimates are obtained across the density spectrum for Golden‐cheeked Warblers and other songbird species.  相似文献   
98.
布鲁斯效应是一种由非配偶雄性的化学信号所诱发的雌性妊娠终止现象,曾被认为是雌性对抗雄性杀婴行为的一种进化策略。布鲁斯效应最初在实验小鼠中发现。后续的研究证明了在实验室条件下多种啮齿类动物中存在布鲁斯效应。布鲁斯效应是否为实验室啮齿类动物中存在的普遍规律,目前尚无定论。本实验首先探讨了布鲁斯效应在金色中仓鼠中是否存在。在交配之后给予实验组雌鼠陌生雄鼠的非直接接触刺激,对照组雌鼠接受配偶雄鼠的非直接接触刺激。同时还测定了雌鼠的体重、胚胎质量以及生理器官(肾上腺、脾脏、卵巢和子宫)质量。结果显示,实验组雌鼠的流产率、体重、胚胎质量、生理器官(肾上腺、脾脏、卵巢、子宫)质量与对照组不存在显著差异。本实验结果表明:陌生雄鼠的化学信号对雌性金色中仓鼠的怀孕状态没有影响,实验室条件下的金色中仓鼠不存在布鲁斯效应。  相似文献   
99.
The number of cells in the S-phase fraction of the cell cycle reflects proliferative activity. Using flow cytometry histograms and the Phoenix M+ cell cycle program, the percent of cells in the S-phase fraction was measured in single cell suspensions prepared from testes of hamsters of different ages. A cyclical pattern with a period of 9 days, superimposed on another rhythm with a 38 day period was observed (p < 0.01) during hamster maturation and it disappeared after the second spermatogenic wave, where the S phase values reached a plateau. It was concluded that maturing animals passed through a stage in which testicular biological rhythm was involved. Therefore it was concluded that it takes approximately two spermatogenic waves before the proliferation rate in the testis reached a steady state.  相似文献   
100.
利用无线电遥测位点分析红腹锦鸡的生境利用   总被引:9,自引:0,他引:9  
为了解红腹锦鸡(Chrysolophus pictus)的生境利用及其季节变化以及对距森林边缘不同距离的生境的利用情况,我们于1996年1月-8月、1998年11月-1999年9月分别在陕西佛坪和贵州宽阔水自然保护区,采用无线电遥测位点与随机点相比较的方法,从不同时空尺度定量分析了红腹锦鸡的生境利用。两研究区共遥测24只红腹锦鸡个体(亚成体和成体,6♂,15♀,3亚♂),其遥测位点分布与随机点比较,冬、春和夏季3季节中均有极显著差异,落入各区域的活动位点与其期望位点数之间也存在着极显著差异。这说明红腹锦鸡对生境的利用不是随机的,而是有选择地利用。红腹锦鸡对距森林边缘不同距离的生境的利用有选择性,并存在着明显的季节变化。分析结果表明,红腹锦鸡在冬、春季对森林边缘和林缘开阔区的利用较多,有一定偏好。红腹锦鸡在两研究区的生境利用模式相似,但在对森林边缘和林缘开阔区的利用强度上,宽阔水研究区显著大于佛坪研究区[动物学报49(2):179一184,2003]。  相似文献   
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