共查询到20条相似文献,搜索用时 15 毫秒
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Signe Preuschoft 《Ethology : formerly Zeitschrift fur Tierpsychologie》1992,91(3):220-236
In an observational study on semi-free Barbary macaques it was investigated whether the phylogenetic roots of human laughter and smile can be traced back to the genus Macaca. On the basis of morphological similarity a ‘relaxed open-mouth display’ as the phylogenetic precursor of the laughter, and a ‘silent bared-teeth display’ as the possible ancestor of the smile can be distinguished in the repertory of the Barbary macaque. Behavioural sequences from focal animal protocols were analyzed in order to establish message and meaning of both displays. Relaxed open-mouth display is regularly observed in the play interactions of juveniles. It is associated with partner-directed behaviour, it is frequently answered by a relaxed open-mouth display of the receiver, and accompanied by a special vocalization. Although up to 50% of the juvenile's play partners were higher ranking than themselves voluntary participation was the rule. Most characteristically, the behaviour patterns shown by both play partners are highly symmetrical and synchronized. Silent bared-teeth display is typically accompanied by evasive or submissive body movements, and occurs primarily in dyadic interactions, mainly by the lower ranking individual. It is not an unidirectional sign of a linear dominance hierarchy, though. Silent bared-teeth display is a frequent answer to aggressive behaviour shown by the receiver. After its performance, an increase of body contact between sender and receiver was observed. Behavioural sequences of senders and receivers are complementary, but lose their asymmetry after occurrence of the display. It is concluded that these results further support Van Hooff 's (1972) view that human laughter and smile have different phylogenetic roots: while silent bared-teeth display is a signal of submission and appeasement, relaxed open-mouth display is rightly called the ‘play face’, and is an expression of fun. 相似文献
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The design of artificial hemoproteins that could lead to new biocatalysts for selective oxidation reactions of organic compounds presents a huge interest especially in pharmacology, both for a better understanding of the metabolic profile of drugs and for the synthesis of enantiomerically pure molecules that could be involved in the design of drugs.The present results show that the so-called “host-guest strategy” that involves the non-covalent incorporation of anionic water-soluble iron-porphyrins into xylanase A from Streptomyces lividans, a low cost protein, leads to such an artificial hemoprotein that is able to perform the stereoselective oxidation of sulfides. 相似文献
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Rosalind Alp 《American journal of primatology》1997,41(1):45-52
In Tenkere, Sierra Leone, a community of wild chimpanzees (Pan troglodytes verus) spent long hours eating the fruits and flowers of the Kapok (Ceiba pentandra) tree. The branches of this species are covered in sharp thorns which make movement in their high canopies problematic for the chimpanzees. In an apparent attempt to increase their mobility and to ease the discomfort of lengthy bouts of eating in these trees, some of the Tenkere chimpanzees have been observed using stick tools as foot (“stepping-sticks”) and body (“seat-sticks”) protection against the painful thorns. This form of tool-using is culturally unique to the Tenkere chimpanzees, as at other sites where these apes have been observed eating parts of kapok trees, there are no published records of this tool technology. In three of the stepping-stick tool use incidents, the chimpanzee used the tool(s), held between their greater and lesser toes, in locomotion. This form of tool use is the first recorded case of habitually used tools that can be justifiably categorized as being “worn” by any known wild population of Pan troglodytes. Am J Primatol 41:45–52, 1997. © 1997 Wiley-Liss, Inc. 相似文献
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Technological progress and adoption are fundamentally interconnected with environmental challenges faced by society. At the product level, researchers often explore the interplay between technological change and the environment by tracking trends in impacts per unit functionality—for example, gasoline consumed per distance traveled by a vehicle. In this article, we explore an alternative measure: “typical product.” A typical product measure accounts for changes in consumers’ demand and use of products as product quality improves—for example, gasoline consumed for a typical driving pattern for a vehicle. We compare and contrast functionality and typical product measures through a case study of electricity use to fabricate Intel desktop microprocessors from 1995 to 2006. The functionality normalization is measured in terms of electricity use per transistor produced. Results show rapid and sustained exponential decrease. The “typical product” measures electricity use per typical desktop microprocessor of a given year (e.g., a Pentium II in 1998, a Pentium IV in 2002). Results show that, despite fluctuations, energy use per typical microprocessor is roughly constant over the 12‐year period. The explanation of this result is that although technological progress dramatically reduces the energy needed per transistor, it also induces demand for more powerful chips, which contain many more transistors. The typical product measure has applications in defining functional units in life cycle assessment, characterizing rebound effects, and measuring energy efficiency trends. 相似文献
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Within the Asteridae (“Sympetalae Tetracyclicae”) two main developmental patterns can be distinguished as regards the formation of corolla tubes, namely “early” and “late sympetaly”. Since the character “ontogeny of sympetaly”, after intensive studies, proved to be valuable for systematic considerations, we now recognize two blocks of orders within the Asteridae (and related groups): the Asteridae A-block and the Asteridae B-block (Figs. 82 and 83). By and large this bipartition referring mainly to the corolla tube development corresponds well with major lineages indentified by recent molecular data (see, e.g., Chase et al., 1993). Asteridae A-block is characterized predominantely by “late sympetaly” the “early sympetaly” in Rubiales and Oleales can be interpreted as derived within this block or can be linked with that in Asteridae B-block. Asteridae B-block is uniform throughout in its “early sympetaly”. In this block it is a primitive character, as judged from its occasional occurrence in the choripetalous Cornales and Apiales (Apiaceae, Araliaceae, Pittosporaceae), which can be regarded as ancestral for block B. 相似文献
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The transdiagnostic expression of psychotic experiences in common mental disorder (anxiety/depression/substance use disorder) is associated with a poorer prognosis, and a small minority of people may indeed develop a clinical picture that meets criteria for schizophrenia. However, it appears neither useful nor valid to observe early states of multidimensional psychopathology in young people through the “schizo”‐prism, and apply misleadingly simple, unnecessary and inefficient binary concepts of “risk” and “transition”. A review of the “ultra‐high risk” (UHR) or “clinical high risk” (CHR) literature indicates that UHR/CHR samples are highly heterogeneous and represent individuals diagnosed with common mental disorder (anxiety/depression/substance use disorder) and a degree of psychotic experiences. Epidemiological research has shown that psychotic experiences are a (possibly non‐causal) marker of the severity of multidimensional psychopathology, driving poor outcome, yet notions of “risk” and “transition” in UHR/CHR research are restrictively defined on the basis of positive psychotic phenomena alone, ignoring how baseline differences in multidimensional psychopathology may differentially impact course and outcome. The concepts of “risk” and “transition” in UHR/CHR research are measured on the same dimensional scale, yet are used to produce artificial diagnostic shifts. In fact, “transition” in UHR/CHR research occurs mainly as a function of variable sample enrichment strategies rather than the UHR/CHR “criteria” themselves. Furthermore, transition rates in UHR/CHR research are inflated as they do not exclude false positives associated with the natural fluctuation of dimensional expression of psychosis. Biological associations with “transition” thus likely represent false positive findings, as was the initial claim of strong effects of omega‐3 polyunsatured fatty acids in UHR samples. A large body of UHR/CHR intervention research has focused on the questionable outcome of “transition”, which shows lack of correlation with functional outcome. It may be more productive to consider the full range of person‐specific psychopathology in all young individuals who seek help for mental health problems, instead of “policing” youngsters for the transdiagnostic dimension of psychosis. Instead of the relatively inefficient medical high‐risk approach, a public health perspective, focusing on improved access to a low‐stigma, high‐hope, small scale and youth‐specific environment with acceptable language and interventions may represent a more useful and efficient strategy. 相似文献
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During study of mother-infant interactions of Macaca fuscata, a low-ranking female was observed to use a stone to groom her infant. At times a twig or piece of chow was used in the same fashion. The grooming involved a circular movement of the object around the infant's eye. The use of the stone appears to fit recent definitions of tool-use. Suggestions are offered regarding the functions of this occasional behavior; however, because of the rarity of its occurrence no conclusion is offered. 相似文献
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Like many economic exchanges, industrial symbiosis (IS) is thought to be influenced by social relationships and shared norms among actors in a network. While many implicit references to social characteristics exist throughout the literature, there have been few explicit attempts to operationalize and measure the concepts. The “short mental distance,”“trust,”“openness,” and “communication” recorded among managers in Kalundborg, Denmark, set a precedent for examining and encouraging social interactions among key personnel in the dozens of eco‐industrial networks around the world. In this article we explore the relationships among various aspects of social embeddedness, social capital, and IS. We develop a conceptual framework and an approach using quantitative and qualitative methods to identify and measure these social characteristics, including social network structure, communication, and similarities in norms and conceptions of waste, and apply them in an industrial network in Nanjangud, South India. The findings suggest that there is a fairly high level of shared norms about dealing with waste—the “short mental distance”—in this network, but by‐product transactions are only weakly correlated with the structure and content of communication among managers. Replication of this approach can increase the understanding and comparability of the role of social characteristics in eco‐industrial activities around the world. 相似文献
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Highly variable regions of DNA are found in a wide diversity of organisms and are typically composed of alleles consisting of a variable number of tandem repeats (VNTRs) of a short core sequence. DNA fingerprinting probes are VNTR probes that simultaneously detect a large number of similar VNTRs in the target DNA. The highly polymorphic pattern observed in a DNA fingerprint allows resolution of questions concerning individual identification. M13 phage was used to fingerprint captive chimpanzees for paternity ascertainment. Although the probability of band sharing among captive chimps appears to be higher than among some other reported captive and feral animal populations, the probe is highly useful and can be expected to become more widely used in the genetic management of captive populations. 相似文献
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M. Kierstan 《Biotechnology and bioengineering》1981,23(4):707-716
The use of calcium alginate gels for the “Solids Separation” techniques was demonstrated by entrapment of a yeast extract in calcium alginate pellets and the study of the release of alcohol dehydrogenase and NADH into a dilute calcium chloride solution. The use of calcium alginate gels for a “Diffusional Chromatography” technique was demonstrated in a model system by a fractionation of NAD and hemoglobin release following their entrapment in calcium alginate pellets. The advantages of these techniques and their potentials are discussed. 相似文献
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New neurons are added to two bilateral clusters of neurons in crayfish brain throughout their lives. These interneurons are associated with the olfactory and accessory lobes, areas of the brain that receive primary olfactory information and higher order inputs from the visual and tactile receptor systems. The rate of cell proliferation in these four clusters, revealed by BrdU labeling, is sensitive to the living conditions of the animals: individuals isolated in small spaces (impoverished condition) exhibit a lower rate of cell proliferation in comparison to their siblings living together in larger areas (enriched condition), although both groups were fed to satiation. Reduction in the rate of proliferation can be measured 1 to 2 weeks after the animals are subjected to the impoverished condition. Counts of the labeled neurons that survive after 4 weeks of subjection to the two conditions show that fewer new neurons survive in the brains of animals that have lived for 2 weeks in the impoverished condition in comparison to their siblings living in the enriched conditions. Factors such as surface area, depth of water, and social interaction can all play a role in determining both the rate of new neuron production and the incorporation of the new neurons into the brain of freshwater crayfish. The results indicate a high degree of neuronal plasticity in the crayfish brain that is highly sensitive to the conditions under which the animals are kept. © 2000 John Wiley & Sons, Inc. J Neurobiol 45: 215–226, 2000 相似文献
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The authors consider that cluster analysis does not objectivize but represents the biologist's subjectivity as to (1) characters considered to be significant and to (2) the way of classification. The latter, however, in authors' opinion, must be specific to the field of application. To this effect some methods are suggested for biology. The methods originate in improvements or transformation of Buser and Baroni-Urbani's method, as well as Watanabe's method, and have the property of processing overall information with no loss or distortion. An agglomerative method which yields a necessarily unique result is suggested, being considered by the authors as a homologue of Watanabe's divisive method. The methods proposed are studied using examples logically constructed. These examples can provide from biology, especially from ecology. 相似文献
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We have performed all atom simulations of blocked peptides of the form (AAXAA)3, where X = Gln, Asn, Glu, Asp, Arg, and Lys with explicit water molecules to examine the interactions between side chains spaced i,i–5 in the sequence. Although side chains in this i,i–5 arrangement are commonly believed to be noninteracting, we have observed the formation of unusual i,i–5 main chain hydrogen bonding in such sequences with positively charged residues (Lys) as well as polar uncharged groups (Gln). Our results are consistent with the unusual percentage of hydrogen bonding curves produced by amide exchange measurements on the well-studied sequence acetyl-(AAQAA)3-amide in water (Shalongo, W., Dugad, L., Stellwagen, E. J. Am. Chem. Soc. 116:8288–8293, 1994). Analysis of our simulations indicated that the glutamine side chain showed the greatest propensity to support π helix formation and that the i,i–5 intramolecular hydrogen bonds were stabilized by water-bridging side chain interactions. This intermittent formation of the unusual π helix structure was observed for up to 23% of the total simulation time in some residues in (AAQAA)3. Control studies on peptides with glutamine side chains spaced i,i–3, i,i–4, and i,i–6 did not reveal similar unique structures, providing stronger evidence for the unique role side chain interactions with i,i–5 spacing. © 1997 Wiley-Liss Inc. 相似文献