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951.
952.
ALAN R. MOOTNICK CLARE CUNNINGHAM ELAINE BAKER 《American journal of primatology》2012,74(11):1035-1043
Although there have been few studies of self‐scratching in primates, some have reported distinct differences in whether hands or feet are used, and these variations seem to reflect the evolutionary history of the Order. Monkeys and prosimians use both hands and feet to self‐scratch while African great apes use hands almost exclusively. Gibbons represent an evolutionary divergence between monkeys and great apes and incidental observations at the Gibbon Conservation Center pointed to a difference in self‐scratching among the four extant gibbon genera (Hoolock, Nomascus, Symphalangus, and Hylobates). To validate and further explore these preliminary observations, we collected systematic data on self‐scratching from 32 gibbons, including nine species and all four genera. To supplement gibbon data, we also collected self‐scratching information from 18 great apes (four species), five prosimians (two species), 26 New World Monkeys (nine species) and 20 Old World Monkeys (seven species). All monkeys and some prosimians used both hands and feet to self‐scratch, whereas one prosimian species used only feet. All African great apes used hands exclusively (orangutans were an exception displaying occasional foot‐use). This appears to represent a fundamental difference between monkeys and great apes in limb use. Interestingly, there was a clear difference in self‐scratching between the four gibbon genera. Hylobates and Symphalangus self‐scratched only with hands (like all African great apes), while Hoolock and Nomascus self‐scratched with both hands and feet (like monkeys and prosimians). This difference in gibbon behavior may reflect the evolutionary history of gibbons as Hoolock and Nomascus are thought to have evolved before both Hylobates and Symphalangus. What evolutionary pressures led to this divergent pattern is currently opaque; however, this shift in limb preference may result from niche separation across the order facilitating differences in the behavioral repertoire associated with hind and forelimbs. Am. J. Primatol. 74:1035‐1043, 2012. © 2012 Wiley Periodicals, Inc. 相似文献
953.
Richard Dean 《Bioethics》2014,28(8):414-419
The stigmatization of some groups of people, whether for some characteristic they possess or some behavior they engage in, will initially strike most of us as wrong. For many years, academic work in public health, which focused mainly on the stigmatization of HIV‐positive individuals, reinforced this natural reaction to stigmatization, by pointing out the negative health effects of stigmatization. But more recently, the apparent success of anti‐smoking campaigns which employ stigmatization of smokers has raised questions about whether stigmatization may sometimes be justified, because of its positive effects on public health. Discussion of the issue so far has focused on consequences, and on some Kantian considerations regarding the status of the stigmatized. In this article, I argue that further Kantian considerations regarding the treatment of the general public (the potential stigmatizers) also count against any public health policy involving stigmatization. Attempts to encourage stigmatization are likely to fail to appeal to the rational decision‐making abilities of the general public, and the creation of stigmatized groups (even if they are stigmatized for their voluntary behavior) is an obstacle to the self‐improvement of members of the general public. 相似文献
954.
We utilised a simple bidirectional (N→C and C→N) solid phase synthesis strategy entailing conventional solid phase peptide synthesis and fragment condensation with a water‐soluble carbodiimide to synthesise a model anionic glycylglycine bolaamphiphile containing a suberic acid linker moiety, namely N,N′‐suberoyldiglycylglycine. The synthetic suberoyldiglycylglycine was purified using its inherent ability to rapidly self‐assemble in an aqueous acidic solution (0.1% trifluoroacetic acid). Monitoring of the rapid assembly process corroborated our visual observation and confirmed packing‐directed self‐assembly rather than non‐specific aggregation or precipitation. The progress of suberoyldiglycylglycine self‐assembly was observed to be via the formation of oligomers in the solution, which then self‐assembled to form layered β‐sheet type macrostructures. Within 24 h, nanotubes grew from these macrostructures and eventually combined to formed microtubes, which we isolated after 5–7 days. Copyright © 2012 European Peptide Society and John Wiley & Sons, Ltd. 相似文献
955.
956.
Zuping Zhou Takintope Akinbiyi Lili Xu Melissa Ramcharan Daniel J. Leong Stephen J. Ros Alexis C. Colvin Mitchell B. Schaffler Robert J. Majeska Evan L. Flatow Hui B. Sun 《Aging cell》2010,9(5):911-915
Aging is a major risk factor for tendon injury and impaired tendon healing, but the basis for these relationships remains poorly understood. Here we show that rat tendon‐derived stem/progenitor cells (TSPCs) differ in both self‐renewal and differentiation capability with age. The frequency of TSPCs in tendon tissues of aged animals is markedly reduced based on colony formation assays. Proliferation rate is decreased, cell cycle progression is delayed and cell fate patterns are also altered in aged TSPCs. In particular, expression of tendon lineage marker genes is reduced while adipocytic differentiation increased. Cited2, a multi‐stimuli responsive transactivator involved in cell growth and senescence, is also downregulated in aged TSPCs while CD44, a matrix assembling and organizing protein implicated in tendon healing, is upregulated, suggesting that these genes participate in the control of TSPC function. 相似文献
957.
Xenorecognition phenomena in coral reefs are expressed by a striking array of morphological and cytological responses. Corals
encountering conspecifics further elicit additional repertoires of effector mechanisms, specific to allogeneic challenges.
Both inducible sets of antagonistic machineries of allo- and xenoresponses are highly specific. In many cases, they are predictable,
reproducible, and reveal the hallmark of coral tissue capacity to distinguish between self and non-self. This essay summarizes
a decade (1992 –2002) of published results on reef coral immune features. While studies on xenorecognition uncovered the existence
of established, non-transitive hierarchies and the importance of antibacterial/cytotoxic compounds secreted by corals, allorecognition
assays disclosed the presence of specific and complex non-transitive hierarchies dictated by the expression of a variety of
effector mechanisms (‘tailored’ against different conspecifics), the existence of gradual maturation of alloresponses (important
in the formation of natural chimeras), the debatable issue of allorecognition memory, and the appearance of delayed, second
sets of alloresponses. A critical evaluation of historecognition reveals that expressed responses in different coral systems
are phenotypically matched with counterpart outcomes recorded in the mammalian immune systems. Histocompatibility in corals,
as in vertebrates, relies on recognition elements (not yet disclosed on the molecular level) as well as on effector mechanisms. 相似文献
958.
Anjali Pandit Nicolas Fay Luc Bordes Céline Valéry Roland Cherif‐Cheikh Bruno Robert Franck Artzner MaÏté Paternostre 《Journal of peptide science》2008,14(1):66-75
We investigated the spectroscopic properties of the aromatic residues in a set of octapeptides with various self-assembly properties. These octapeptides are based on lanreotide, a cyclic peptide analogue of somatostatin-14 that spontaneously self-assembles into very long and monodisperse hollow nanotubes. A previous study on these lanreotide-based derivatives has shown that the disulfide bridge, the peptide hairpin conformation and the aromatic residues are involved in the self-assembly process and that modification of these properties either decreases the self-assembly propensity or modifies the molecular packing resulting in different self-assembled architectures. In this study we probed the local environment of the aromatic residues, naphthyl-alanine, tryptophan and tyrosine, by Raman and fluorescence spectroscopy, comparing nonassembled peptides at low concentrations with the self-assembled ones at high concentrations. As expected, the spectroscopic characteristics of the aromatic residues were found to be sensitive to the peptide-peptide interactions. Among the most remarkable features we could record a very unusual Raman spectrum for the tyrosine of lanreotide in relation to its propensity to form H-bonds within the assemblies. In Lanreotide nanotubes, and also in the supramolecular architectures formed by its derivatives, the tryptophan side chain is water-exposed. Finally, the low fluorescence polarization of the peptide aggregates suggests that fluorescence energy transfer occurs within the nanotubes. 相似文献
959.
《Anthrozo?s》2013,26(4):329-343
ABSTRACTThis research examined whether self psychology could be systematically applied to human–animal relationships. Twenty-four semi-structured interviews were conducted, which consisted of 16 questions designed to illuminate selfobject needs. The interviews were intended to identify whether the horse/dog/cat/rabbit was a selfobject, that is, a provider of self-cohesion, self esteem, calmness, soothing, and acceptance, for the participant and, if so, whether the primary type(s) of selfobject was mirroring, idealizing, or twinship. Results revealed that self psychology could be applied successfully to human–animal relationships, that it could usually be determined whether the animal served a selfobject function, and that selfobject type was generally able to be established. In this sample, animals rivaled and even surpassed humans in their ability to provide important selfobject needs. 相似文献
960.
Abstract The physics of the van der Pol oscillator as realized by the Meissner circuit is discussed by analogy to the beat phenomenon and by a consequent analysis of current balance. The current balance method leads to a new, very accurate equation for the dependence of the oscillator frequency on the feedback parameter. Several aspects of entrainment (existence, limited frequency range, dependence on parameters, phase shift) can be explained, too. Numerical results are presented which have been obtained by solving the homogeneous and inhomogeneous van der Pol equation with a Runge‐Kutta method. 相似文献