共查询到20条相似文献,搜索用时 15 毫秒
1.
Benjamin B. Beck 《Journal of human evolution》1974,3(6):509-516
Wild chimpanzees make and use tools with far greater frequency and variety than wild baboons. Sampling differences; differences in the sensory, motor, or cognitive capacities for skilled tool use; or environmental differences are not responsible. Fortuitous discovery of novel forms of tool behavior probably occurs as rarely among chimpanzees as among baboons. However, research on wild and captive chimpanzees reveals that the discovery is transmitted quickly among chimpanzee groups by observation learning, and thus becomes well-established in the group's behavioral repertoire. In contrast, study of captive baboons reveals that they acquire little information about tool behavior by observation. With little observation learning the behavior is not likely to be acquired by other group members since repeated independent discovery is improbable. Thus chimpanzees' more proficient tool behavior is due mainly to their greater capacity for observation learning. This suggests that the advent of hominid tool traditions was accompanied by a capacity for facile observation learning and thus, perhaps, by language ability. 相似文献
2.
城市生态系统长期观测是开展城市生态安全评价和制定人居环境健康管理政策的基础。为了确保城市生态观测数据的准确性和科学性,通过辨识城市生态观测质量控制的概念,基于"人机料法环"理论构建了城市生态观测质量控制体系,结合城市生态观测质量控制相关规范的编制与实施现状,探讨了城市生态观测质量控制规范的编制技术。结果表明:(1)城市生态观测质量控制是面向城市生态观测内容(要素、空间格局、功能、服务),为保证生态观测全过程质量要求、提高生态观测结果的准确性而实施的质量控制活动和措施。(2)城市生态观测质量控制体系可从对象和过程这两个维度进行界定:对象维度方面,包括"人"-人员、"机"-仪器设备、"料"-数据、"法"-文件和"环"-观测过程5个方面;过程维度方面,涵盖城市生态观测全过程,包括城市生态观测前期准备工作、观测过程中以及观测后的数据录入、审核与评价等环节的质量控制措施。(3)我国已发布的生态观测相关技术标准中,发布的时间越晚,质量控制内容越完整,目前生态观测相关标准共102则,仅38则明确提出了质量控制具体要求。(4)《城市生态观测质量控制规范》编制需包含质量体系和质量控制措施两项技术内容,主要包括前引、正文和附录三个章节,对生态观测全过程质量保证和质量控制技术进行规定。 相似文献
3.
The coupling process between observed and performed actions is thought to be performed by a fronto-parietal perception-action system including regions of the inferior frontal gyrus and the inferior parietal lobule. When investigating the influence of the movements' characteristics on this process, most research on action observation has focused on only one particular variable even though the type of movements we observe can vary on several levels. By manipulating the visual perspective, transitivity and meaningfulness of observed movements in a functional magnetic resonance imaging study we aimed at investigating how the type of movements and the visual perspective can modulate brain activity during action observation in healthy individuals. Importantly, we used an active observation task where participants had to subsequently execute or imagine the observed movements. Our results show that the fronto-parietal regions of the perception action system were mostly recruited during the observation of meaningless actions while visual perspective had little influence on the activity within the perception-action system. Simultaneous investigation of several sources of modulation during active action observation is probably an approach that could lead to a greater ecological comprehension of this important sensorimotor process. 相似文献
4.
Pearson CH 《History and philosophy of the life sciences》2010,32(4):475-492
Pattern cladists purport to classify biological taxa in a way that is theory-neutral. The idea of a theory-neutral science is, however, philosophically problematic; and, while pattern cladists' commitment to theory-neutrality has been subject to scrutiny by both phylogenetic cladists and some philosophers, virtually no attention has been paid to the core issue of whether observation of patterns in nature is a means to theory-neutrality. This essay critically examines pattern cladists' claim to construct a theory-neutral cladistic taxonomy by relying on observation. Special attention is paid to the observations of patterns involving homologous traits. 相似文献
5.
Salmi Pauliina Calderini Marco Pääkkönen Salli Taipale Sami Pölönen Ilkka 《Journal of applied phycology》2022,34(3):1565-1575
Journal of Applied Phycology - Effective monitoring of microalgae growth is crucial for environmental observation, while the applications of this monitoring could also be expanded to commercial and... 相似文献
6.
In the present contribution the distributive pattern of phosphatases and non-specific esterase amongst the constituents of the leech eye has been revealed and the significance of the enzymatic locales in relation to the visual processes has been discussed. All the phosphatases studied demonstrate absence of the activity in the lens. Activity of the phosphatases, however, is restricted to the plasma membrane and associated cytoplasm to varying degrees. The significance of the phosphatases in the nerve impulses and transmission has been highlightened. The observation of considerable significance relates the demonstration of a high degree of non-specific esterase activity in the lens, which has defied all the phosphatases. Another observation relates to the positive activity of 5-nucleotidase in the group of axons constituting optic nerve. The significance of this observation has also been discussed. 相似文献
7.
N. Rashevsky 《Bulletin of mathematical biology》1973,35(3):339-344
The phenomenon of mental creativity is considered from the standpoint of the theory of organismic sets, developed by the author
in a series of previous publications. It is shown how the differences in creativity between different individuals may be interpreted
on this basis, and why extreme creativity is rare. A parallel interpretation for facility in observation is given, and it
is shown why facility in creativity and observation is much rarer than either individual facility. A further conclusion is
drawn regarding the deducibility of the laws of nature by purely logical means. 相似文献
8.
9.
Hans G. Othmer 《Mathematical biosciences》1984,71(1):121-122
The occupancy principle and the mean-transit-time theorem are derived for the passage of a tracer through a system that can be described by a general pool model. It is proved, using matrix theory, that if (and only if) tracer entering the system labels equally all tracee fluxes into the system, then the integral of the tracer concentration is the same in all the pools. It is also proved that if, in addition, all flow out of the system is through the observation point, the first moment of the tracer concentration at the observation point can be used to calculate the total amount of trace in the system. The necessity of this condition is analyzed. Examples are given of models in which the occupancy principle and the mean-transit-time theorem hold or do not hold. 相似文献
10.
Gonadotropin-releasing hormone: molecular and cell biology, physiology, and clinical applications 总被引:1,自引:0,他引:1
The observations in recent years that gonadotropin-releasing hormone ( pyroGlu1 -His2-Trp3- Ser4 -Tyr5- Gly6 -Leu7-Arg8-Pro9- G ly10NH2 [GnRH]) has considerable clinical efficacy as a contraceptive, an ovulation-inducing agent, and a drug that is useful in the therapy of a number of diseases are owed in no small part to advances that have been made in the basic molecular biology and physiology of this peptide. It is reasonable then that this symposium should be broken down into three separate yet integrated areas: 1) the molecular and cellular biology of GnRH, 2) the physiology of GnRH, and 3) the clinical efficacy of this compound. A number of recent advances have helped the progress of work in all three of these areas. The observation that substitution of a D-amino acid in the sixth amino acid position leads to considerable metabolic stability and reduced degradation of releasing hormone analogs has been especially useful. In addition, the observation that the further derivatization of such substituted compounds by deletion of the 10th amino acid and addition of an ethylamide group to Pro9 has resulted in compounds with a markedly increased ability to bind to the receptor. These compounds have been useful clinically and have allowed development of radioligand assays to be used in animal studies and in vitro. The availability of a large number of agonists and antagonists has allowed formulation of molecular models for GnRH and resulted in development of clinically useful compounds. In a short paper of this nature we cannot hope to provide an encyclopedic review; rather we hope to provide an overview and offer references to the literature for those who wish a more in-depth treatment. 相似文献
11.
Theodor Boveri (1862-1915) is often credited with suggesting (in 1914) the first chromosomal theory of cancer, especially in terms of abnormal numbers of chromosomes arising in cells by multipolar mitoses in adult cells. However, multipolar mitoses in animal cells had been described as early as 1875, and Hansemann (1858-1920), in publications between 1890 and 1919, included this mechanism among various ways by which abnormal chromosome numbers might arise in cells and cause tumour formation. Both theories were conceived in a period when gametogenic ideas of tumour formation were current. Boveri based his theory on the observation that some cells in early sea urchin embryos having abnormal chromosome complements wander from their usual developmental paths. His observation may have been seen by other authors at the time as support for Cohnheim's "embryonic cell rest" theory of cancer. Hansemann's contribution is seen as both the original, and the more significant of the chromosomal theories of cancer. 相似文献
12.
目的:研究腹腔镜肝癌切除术对肝细胞癌中的治疗效果及对血清AFP、sEC、HGF、ICAM-1的影响。方法:选择2012年3月至2017年3月在我院接受治疗的肝细胞癌患者196例,根据治疗方案不同分为观察组和对照组,对照组给予开腹切除术治疗,观察组给予腹腔镜切除术治疗。观察并比较两组手术前后血清甲胎蛋白(AFP)、sEC、人类生长因子(HGF)、细胞间黏附分子-1(ICAM-1)及总胆红素(TBIL)、直接胆红素(DBIL)、谷丙转氨酶(ALT)及白蛋白(Alb)水平,术中出血量、术后绝对卧床时间、住院时间以及并发症发生率。结果:术后,观察组血清AFP、sEC、HGF、ICAM-1水平均明显低于对照组(P0.05);观察组TBIL、DBIL、ALT水平均显著低于对照组,Alb则显著高于对照组(P0.05);观察组术中出血量、绝对卧床时间以及住院时间均明显低于对照组(P0.05);且观察组术后并发症发生率明显低于对照组(P0.05)。结论:使用腹腔镜肝癌切除术治疗肝细胞癌,可降低患者血清AFP、sEC、HGF、ICAM-1水平从而提高其治疗效果,且术后并发症发生率较低。 相似文献
13.
为分析综合护理干预对百草枯中毒患者临床治疗预后的效果,本研究选取2015年5月至2016年12月我院收治的百草枯中毒患者92例,根据护理方法不同分为对照组和观察组。对照组患者采用常规护理模式进行干预,观察组患者采用综合护理模式进行干预,分析两组患者护理后的效果。研究发现,观察组患者治愈率、7 d存活率和30 d存活率高于对照组,口腔黏膜愈合时间、住院时间短于对照组(p<0.05)。干预前,两组患者hs-CRP、IL-10、ASL、ALT水平比较无统计学差异(p>0.05)。干预后,观察组患者hs-CRP、IL-10、ASL、ALT水平低于对照组(p<0.05)。干预前,两组患者焦虑、抑郁评分比较无统计学差异(p>0.05)。干预后,观察组患者焦虑、抑郁评分低于对照组(p<0.05)。本研究的结果说明,百草枯中毒患者采用综合护理干预可加快患者口腔黏膜愈合时间,提高治愈率、存活率,改善患者心理状况,值得临床推广及进一步规范研究。 相似文献
14.
Ney Shahuano Tello Mojca Stojan-Dolar Eckhard W. Heymann 《Journal of Ornithology》2008,149(2):267-269
This paper reports on the observation of an oilbird, Steatornis caripensis, in Peruvian lowland Amazonia in September 2006, and discusses this sighting in relation to other lowland reports of oilbirds.
Taken together, available information indicates that oilbirds seem to occur in lowland Amazonia more regularly than previously
known. 相似文献
15.
Bastolla U Porto M Eduardo Roman MH Vendruscolo MH 《Journal of molecular evolution》2003,56(3):243-254
Abstract
Protein structures are much more conserved than sequences during evolution. Based on this observation, we investigate the
consequences of structural conservation on protein evolution. We study seven of the most studied protein folds, determining
that an extended neutral network in sequence space is associated with each of them. Within our model, neutral evolution leads
to a non-Poissonian substitution process, due to the broad distribution of connectivities in neutral networks. The observation
that the substitution process has non-Poissonian statistics has been used to argue against the original Kimura neutral theory,
while our model shows that this is a generic property of neutral evolution with structural conservation. Our model also predicts
that the substitution rate can strongly fluctuate from one branch to another of the evolutionary tree. The average sequence
similarity within a neutral network is close to the threshold of randomness, as observed for families of sequences sharing
the same fold. Nevertheless, some positions are more difficult to mutate than others. We compare such structurally conserved
positions to positions conserved in protein evolution, suggesting that our model can be a valuable tool to distinguish structural
from functional conservation in databases of protein families. These results indicate that a synergy between database analysis
and structurally based computational studies can increase our understanding of protein evolution. 相似文献
16.
摘要 目的:通过腰硬联合麻醉在下肢骨折手术中对白细胞(white blood cell,WBC)、白蛋白(albumin,ALB)、C-反应蛋白(C-reactive protein,CRP)、降钙素原(procalcitonin,PCT)的影响分析,探讨腰硬联合麻醉在下肢骨折手术中的应用价值。方法:选取本院2018年12月到2019年10月择期髋部骨折手术的老年患者88例,按不同麻醉方法分为观察组(n=48)与对照组(n=40);对照组为全身麻醉,观察组为腰硬联合麻醉,以WBC、CRP、ALB、PCT为观察指标,结合术后疼痛及术中麻醉效果对腰硬联合麻醉在下肢骨折手术中的应用进行分析评价。结果:观察组术后4 h、24 h、48 h的静息疼痛评分都显著低于对照组(P<0.05)。观察组的感觉阻滞时间、阻滞完善时间、痛觉恢复时间都显著短于对照组(P<0.05)。观察组术后1 d、7 d的WBC、ALB值与对照组对比差异无统计学意义(P>0.05),观察组术后1 d、7 d的血清CRP、PCT含量都显著低于对照组(P<0.05)。结论:腰硬联合麻醉在下肢骨折手术中的应用并不会影响WBC、ALB的表达,但可减轻CRP、PCT的血浓度,能更好的提高麻醉效果,发挥镇痛作用,延长术后无痛时间,从而促进患者的康复。 相似文献
17.
The spatial distribution and dispersion of Anaphothrips obscurus (Müller) (Thysanoptera: Thripidae) was examined with the goal of establishing a sequential sampling plan for this pest in timothy, Phleum pratense L. (Poaceae). Approximately 16 different California timothy fields were sampled twice yearly from 2006 to 2008 using direct observation and the beat cup method. For direct observation, the number of thrips on each leaf of the plant was counted. For the beat cup method, tillers were tapped into a cup and dislodged thrips were counted. Samples were separated by ≈3 m in 2006 and 2007 and exactly 3 m in 2008. Spatial autocorrelation of intrafield population distribution was tested for significance in 2008 using Moran's I, but autocorrelation was not detected. The population dispersion was assessed by Taylor's power law and was determined to be aggregated and density-dependent. Intraplant population dispersion and distribution for each year were also evaluated for adults, larvae, and total thrips. All lifestages were highly spatially dependent and more thrips were found near the top of the plant than the bottom. Direct observation proved to be a more accurate and precise method than the beat cup method, especially when thrips abundances were greater than one. However, the number of samples required to provide an accurate level of precision was unrealistic for both methods. A sequential sampling plan was evaluated, but was not practical for the beat cup method because few thrips were found using this method. Because there was no spatial autocorrelation at sampling distances of 3 m, samples can be taken at intervals at 3 m to obtain spatially independent population abundance estimates. 相似文献
18.
ROLAND KELLER 《Botanical journal of the Linnean Society. Linnean Society of London》1994,116(1):33-51
Some taxonomic characters may escape observation when only a small part of the vegetative body of the plant is examined. For this reason, these characters are likely to be overlooked. Phyllotaxy varies in most cases from the trunk to branches. Serial buds, when they exist, may be lacking in the axil of some leaves. Syllepsis is easier to see on the trunk than on twigs. Architectural models are established after appropriate observation of the whole plant or, better, with different individuals of the same species. Nevertheless, many of these characters can be readily observed and frequently help to identify a woody plant without its flowers or fruits. Some interpretations concerning systematics and evolutionary biology are also given. 相似文献
19.
Jorge Vieira Nuno A Fonseca Raquel A M Santos Tsuyoshi Habu Ryutaro Tao Cristina P Vieira 《Genetical research》2008,90(1):17-26
In gametophytic self-incompatibility systems, many specificities (different 'lock-and-key' combinations) are maintained by frequency-dependent selection for very long evolutionary times. In Solanaceae, trans-specific evolution (the observation that an allele from one species may be more closely related to an allele from another species than to others from the same species) has been taken as an argument for the very old age of specificities. In this work, by determining, for the first time, the age of extant Prunus species, we show that this reasoning cannot be applied to Prunoideae. Furthermore, since our sample size is large (all S-RNase encoding the female component and SFB encoding the male component GenBank sequences), we were able to estimate the age of the oldest Prunus specificities. By doing so, we show that the lower variability levels at the Prunus S-locus, in comparison with Solanaceae, is due to the younger age of Prunus alleles, and not to a difference in silent mutation rates. We show that the ancestor to extant Prunus species harboured at least 102 specificities, in contrast to the maximum of 33 observed in extant Prunus species. Since the number of specificities that can be maintained in a population depends on the effective population size, this observation suggests a bottleneck in Prunus evolutionary history. Loss of specificities may have occurred during this event. Using only information on amino acid sites that determine specificity differences, and a simulation approach, we show that a model that assumes closely related specificities are not preferentially lost during evolution, fails to predict the observed degree of specificity relatedness. 相似文献
20.
The amino acid sequence of the carboxyl-terminal half of barley trypsin inhibitor was found to be significantly similar to the whole sequence of bovine pancreatic secretory trypsin inhibitor (Kazal). Kazal type inhibitors and related proteins are known for the extraordinary mode of divergence among animals, and the present observation extends this to a plant for the first time. The present observation together with our previous finding of sequence homology between barley trypsin inhibitor and wheat alpha-amylase inhibitor (Odani, S., Koide, T., & Ono, T. (1982) FEBS Lett. 141, 279-282) suggest an unusual evolutionary relationship between cereal enzyme inhibitors and animal proteinase inhibitors of the Kazal type. 相似文献