首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
《Plains anthropologist》2013,58(48):99-103
Abstract

Sexual intimacy as a means of transferring spiritual power appears to have been a Mandan-Hidatsa ceremonial trait borrowed by three Algonkian Plains tribes as part of the graded men’s societies complex. The Algonkian tribes modified the rite, which in the village tribes emphasized the role of father’s clan. The Arapaho emphasized the cosmic symbolism of the rite, the Atsina made it a test of self-discipline, and the Blackfoot stressed the dangerous power commanded by those who performed it. These modifications parallel the differences in kinship structure between village and nomadic Plains tribes discussed by Eggan.  相似文献   

2.
Sound symbolism is a non-arbitrary relationship between speech sounds and meaning. We review evidence that, contrary to the traditional view in linguistics, sound symbolism is an important design feature of language, which affects online processing of language, and most importantly, language acquisition. We propose the sound symbolism bootstrapping hypothesis, claiming that (i) pre-verbal infants are sensitive to sound symbolism, due to a biologically endowed ability to map and integrate multi-modal input, (ii) sound symbolism helps infants gain referential insight for speech sounds, (iii) sound symbolism helps infants and toddlers associate speech sounds with their referents to establish a lexical representation and (iv) sound symbolism helps toddlers learn words by allowing them to focus on referents embedded in a complex scene, alleviating Quine''s problem. We further explore the possibility that sound symbolism is deeply related to language evolution, drawing the parallel between historical development of language across generations and ontogenetic development within individuals. Finally, we suggest that sound symbolism bootstrapping is a part of a more general phenomenon of bootstrapping by means of iconic representations, drawing on similarities and close behavioural links between sound symbolism and speech-accompanying iconic gesture.  相似文献   

3.
This article explains the ritual symbolism of a sacrificial rite characteristic of the so-called 'secret societies' of the conflict-ridden Upper Guinea forest and coastal region of West Africa. Whereas the political dimension of these secret societies or cults is relatively well known, very little knowledge exists about the ritual communication with imperceptible beings around which the cults are organized. It appears from the study of Loma ritual prayer that secret mask cults are typical self-referential entities constituted by a symbolism emerging from a reconfiguration in ritual speech of modes of relationships characteristic of the social structure of the Loma of Guinea and Liberia. Against recent anthropological theories of ritual which reject the idea that ritual can be defined as communication of meaning, it is argued that Loma sacrificial prayer conveys an essential 'message' about the secret cult's constitution. In addition to an analysis of the recontextualization of modes of relationships that typifies Loma ritual prayer, the article also pays attention to indexical expressions in prayer which serve to negotiate social relationships and power relations external to the ritual context.  相似文献   

4.
Sexual selection has resulted in sex-based size dimorphism in many mammals, including humans. In Western societies, average to taller stature men and comparatively shorter, slimmer women have higher reproductive success and are typically considered more attractive. This size dimorphism also extends to vocalisations in many species, again including humans, with larger individuals exhibiting lower formant frequencies than smaller individuals. Further, across many languages there are associations between phonemes and the expression of size (e.g. large /a, o/, small /i, e/), consistent with the frequency-size relationship in vocalisations. We suggest that naming preferences are a product of this frequency-size relationship, driving male names to sound larger and female names smaller, through sound symbolism. In a 10-year dataset of the most popular British, Australian and American names we show that male names are significantly more likely to contain larger sounding phonemes (e.g. “Thomas”), while female names are significantly more likely to contain smaller phonemes (e.g. “Emily”). The desire of parents to have comparatively larger, more masculine sons, and smaller, more feminine daughters, and the increased social success that accompanies more sex-stereotyped names, is likely to be driving English-language first names to exploit sound symbolism of size in line with sexual body size dimorphism.  相似文献   

5.
Bomati EK  Noel JP 《The Plant cell》2005,17(5):1598-1611
We describe the three-dimensional structure of sinapyl alcohol dehydrogenase (SAD) from Populus tremuloides (aspen), a member of the NADP(H)-dependent dehydrogenase family that catalyzes the last reductive step in the formation of monolignols. The active site topology revealed by the crystal structure substantiates kinetic results indicating that SAD maintains highest specificity for the substrate sinapaldehyde. We also report substantial substrate inhibition kinetics for the SAD-catalyzed reduction of hydroxycinnamaldehydes. Although SAD and classical cinnamyl alcohol dehydrogenases (CADs) catalyze the same reaction and share some sequence identity, the active site topology of SAD is strikingly different from that predicted for classical CADs. Kinetic analyses of wild-type SAD and several active site mutants demonstrate the complexity of defining determinants of substrate specificity in these enzymes. These results, along with a phylogenetic analysis, support the inclusion of SAD in a plant alcohol dehydrogenase subfamily that includes cinnamaldehyde and benzaldehyde dehydrogenases. We used the SAD three-dimensional structure to model several of these SAD-like enzymes, and although their active site topologies largely mirror that of SAD, we describe a correlation between substrate specificity and amino acid substitution patterns in their active sites. The SAD structure thus provides a framework for understanding substrate specificity in this family of enzymes and for engineering new enzyme specificities.  相似文献   

6.
Shan ZZ  Dai SM  Fang F  Su DF 《生理学报》2003,55(1):75-78
既往的研究表明,动脉压力感受性反射(ABR)功能下降在高血压靶器官损伤中起独立作用。为进一步研究ABR功能下降致器官损伤的可能机制,实验采用去窦弓神经(SAD)大鼠作为ABR受损的动物模型,分别测定清醒、自由活动状态下SAD及对照的假手术组大鼠24h动脉血压、心率、血压波动性(BPV)及心率波动性(HRV)。并采用放免法测定血浆、心脏和肾脏组织的血管紧张素Ⅱ(AngⅡ)含量。结果发现,SAD术后1周大鼠的24h平均收缩压(SBP)、舒张压(DBP)均显著高于对照组及术后18周的慢性期SAD大鼠。SAD术后18周,24h平均SBP、DBP及HR与假手术对照组均无显著差异;24h收缩压波动性(SBPV)和舒张压波动性(DBPV)均显著高于对照组大鼠。SAD大鼠术后1周的血浆、心脏和肾脏组织的AngⅡ含量及术后18周的血浆AngⅡ水平与对照组之间相比无显著差异。而在术后慢性期(18周),SAD大鼠的心肌及肾组织AngⅡ含量显著高于假手术对照组大鼠。在术后18周时,接受慢性应激刺激的SAD大鼠,其血浆、心肌及肾组织中AngⅡ水平显著高于同处应激状态下的假手术对照组大鼠及未接受应激刺激的SAD大鼠。这些结果表明,SAD术后急性期血压增高,但在慢性期平均血压并无增高,仅BPV增高;慢性期心、肾组织内AngⅡ的分泌增加。在慢性期接受应激可致AngⅡ过度分泌,上述结果提示,BPV增高和心、肾组织AngⅡ含量升高与SAD大鼠发生心脏、肾脏等器官损害有关。  相似文献   

7.
Community ecologists have attempted to explain species abundance distribution (SAD) shape for more than 80 years, but usually without relating SAD shape explicitly to ecological variables. We explored whether the scale (total assemblage abundance) and shape (assemblage evenness) of avifaunal SADs were related to ecological covariates. We used data on avifaunas, in-site habitat structure and landscape context that were assembled from previous studies; this amounted to 197 transects distributed across 16,000 km2 of the box-ironbark forests of southeastern Australia. We used Bayesian conditional autoregressive models to link SAD scale and shape to these ecological covariates. Variation in SAD scale was relatable to some ecological covariates, especially to landscape vegetation cover and to tree height. We could not find any relationships between SAD shape and ecological covariates. SAD shape, the core component in SAD theory, may hold little information about how assemblages are governed ecologically and may result from statistical processes, which, if general, would indicate that SAD shape is not useful for distinguishing among theories of assemblage structure.  相似文献   

8.
We examined how climate-mediated forest dieback regulates zoonotic disease prevalence using the relationship between sudden aspen decline (SAD) and Sin Nombre virus (SNV) as a model system. We compared understory plant community structure, small mammal community composition, and SNV prevalence on 12 study sites within aspen forests experiencing levels of SAD ranging from <10.0% crown fade to >95.0% crown fade. Our results show that sites with the highest levels of SAD had reduced canopy cover, stand density, and basal area, and these differences were reflected by reductions in understory vegetation cover. Conversely, sites with the highest levels of SAD had greater understory standing biomass, suggesting that vegetation on these sites was highly clustered. Changes in forest and understory vegetation structure likely resulted in shifts in small mammal community composition across the SAD gradient, as we found reduced species diversity and higher densities of deer mice, the primary host for SNV, on sites with the highest levels of SAD. Sites with the highest levels of SAD also had significantly greater SNV prevalence compared to sites with lower levels of SAD, which is likely a result of their abundance of deer mice. Collectively, results of our research provide strong evidence to show SAD has considerable impacts on vegetation community structure, small mammal density and biodiversity and the prevalence of SNV.  相似文献   

9.
Sound symbolism, or the nonarbitrary link between linguistic sound and meaning, has often been discussed in connection with language evolution, where the oral imitation of external events links phonetic forms with their referents (e.g., Ramachandran & Hubbard, 2001). In this research, we explore whether sound symbolism may also facilitate synchronic language learning in human infants. Sound symbolism may be a useful cue particularly at the earliest developmental stages of word learning, because it potentially provides a way of bootstrapping word meaning from perceptual information. Using an associative word learning paradigm, we demonstrated that 14-month-old infants could detect Köhler-type (1947) shape-sound symbolism, and could use this sensitivity in their effort to establish a word-referent association.  相似文献   

10.
Simultaneous ANAMMOX and denitrification (SAD) process in batch tests   总被引:1,自引:0,他引:1  
The occurrence of simultaneous anaerobic ammonia oxidation and nitrate reduction (SAD) processes by enrichment culture in the presence of glucose were clarified in batch tests. Nitrate conversion and the formation of interim by-products were investigated under autotrophic and mixotrophic conditions. Eventually, the nitrite was fully consumed and co-occurred with ammonia oxidation. The effect of penicillin G and methanol on the SAD process was also investigated. Methanol addition led to complete loss of ANAMMOX activity at concentrations as low as 1?mM. Penicillin G has little effect on the SAD process. Scanning electron microscopy (SEM) observation and denaturing gradient gel electrophoresis (DGGE) analysis revealed that ANAMMOX bacteria and co-existing bacteria are responsible for the SAD process. In conclusion, this study indicates that the ratio of nitrogen to organic carbon, and the cooperation and competition between microbes can affect the dynamics of this process. It has a potential application to remove ammonia and nitrate in the presence of organic matter by the SAD process.  相似文献   

11.
The arterial baroreflex pathway provides the fundamental basis for the short-term control of blood pressure via the rapid regulation of the mean level of sympathetic nerve activity (SNA) in response to changes in blood pressure. A central tenet in the generation and regulation of bursts of SNA is that input from the arterial baroreceptors also regulates the timing of the bursts of sympathetic activity. With the use of an implantable telemetry-based amplifier, renal SNA was recorded in intact and arterial baroreceptor-denervated (SAD) conscious rabbits. Data were collected continuously while animals were in their home cage. Mean levels of SNA were not different between SAD and baroreceptor-intact animals. Whereas SNA was unresponsive to changes in blood pressure in SAD rabbits, the timing of the bursts of SNA relative to the arterial pulse wave was maintained (time between the diastolic pressure and the next maximum SNA voltage averaged 107+/-12 ms SAD vs. 105+/-7 ms intact). Transfer function analysis between blood pressure and SNA indicates the average gain at the heart rate frequency was not altered by SAD, indicating strong coupling between the cardiac cycle and SNA bursts in SAD animals. Further experiments in anesthetized rabbits showed that this entrainment is lost immediately after performing baroreceptor denervation surgery and remained absent while the animal was under anesthesia but returned within 20 min of turning off the anesthesia. We propose that this finding indicates the regulation of the mean level of SNA requires the majority of input from baroreceptors to be functional; however, the regulation of the timing of the bursts in the conscious animal requires only minimal input, such as a sensitive trigger mechanism. This observation has important implications for understanding the origin and regulation of SNA.  相似文献   

12.
Species abundance distribution (SAD) is a classic topic of multispecies ecology. Different types of SAD may indicate specific environmental conditions. A possible way to present some properties of a theoretical or empirical SAD is the construction of a rank-abundance curve (RAC). With regard to the applicability of the RAC as a widely used indicator of the structure of a multispecies community and of the ecological status of its habitat, a basic question is the link between the type of SAD and the shape of the associated RAC. One of the simplest ways to characterize a RAC is to determine its concave and convex segments. However, none of ecological textbooks does give a clear-cut guideline concerning this issue. In the paper a connection is presented between some types of SAD and the convex and concave segments of the related RAC: including among others linearity for the geometric SAD (e.g. with communities in early stage of succession), convexity for the Zipf-Mandelbrot SAD (e.g. with communities with slow successional process), and convexity and then concavity with an inflexion point at approximately the mode of the associated histogram for the lognormal SAD (e.g. with climax, equilibrium communities). Our approach has the potential to improve and justify the use of RACs when searching for the determinants of community structure, initiating further studies in this field.  相似文献   

13.
This study was designed to assess the effect of the dimethyl ester of succinic acid (SAD) upon the hormonal and metabolic response to a 60-min exercise in overnight-starved Goto-Kakizaki rats. Twenty Goto-Kakizaki rats were starved overnight and then either maintained at rest or obliged to swim for 60 min. Half of the rats were injected intraperitoneally with the dimethyl ester of succinic acid (SAD, 5.0 micromol g(-1) body wt) immediately before exercise (or 60 min of rest). In the hereditarily diabetic rats, overnight starvation lowered the plasma D- glucose, insulin and lactate concentrations, while increasing that of free fatty acids and beta-hydroxybutyrate. In resting rats, the injection of SAD increased the glycogen content of liver, heart and muscle and the plasma concentration of D-glucose, insulin, glycerol and free fatty acids. In control animals, not injected with SAD, exercise increased the plasma concentration of D- glucose, lactate and glycerol, whilst lowering both that of insulin and the glycogen content of liver, heart and muscle. The injection of SAD before exercise failed to prevent and, on occasion, even accentuated the changes in both the glycogen content of liver, heart and muscle and the plasma concentration of D-glucose, insulin, glycerol and free fatty acids, whilst minimizing the increase in lactate concentration otherwise caused by exercise. Nevertheless, the comparison between resting and exercising rats, both injected with SAD, suggested that the ester abolished the exercise-induced rise in D-glucose, glycerol and fatty acid concentrations. By comparison with comparable experiments conducted in overnight-starved normal rats, these findings emphasize both the difference between normal and diabetic rats in their metabolic response to exercise, especially in terms of changes in glycemia, and the usefulness of SAD to compensate for the increased consumption of endogenous nutrients during exercise.  相似文献   

14.
SAD mutation of Saccharomyces cerevisiae is an extra a cassette.   总被引:8,自引:5,他引:3       下载免费PDF全文
Sporulation of Saccharomyces cerevisiae ordinarily requires the a1 function of the a mating type locus. SAD is a dominant mutation that allows strains lacking a1 (MAT alpha/MAT alpha and mata1/MAT alpha diploids) to sporulate. We provide functional and physical evidence that SAD is an extra cassette in the yeast genome, distinct from those at HML, MAT, and HMR. The properties of SAD strains indicate that the a cassette at SAD produces a limited amount of a1 product, sufficient for promoting sporulation but not for inhibiting mating and other processes. These conclusions come from the following observations. (i) SAD did not act by allowing expression of HMRa: mata1/MAT alpha diploids carrying SAD and only alpha cassettes at HML and HMR sporulated efficiently. (ii) SAD acted as an a cassette donor in HML alpha HMR alpha strains and could heal a mata1 mutation to MATa as a result of mating type interconversion. (iii) The genome of SAD strains contained a single new cassette locus, as determined by Southern hybridization. (iv) Expression of a functions from the SAD a cassette was limited by Sir: sir- SAD strains exhibited more extreme phenotypes than SIR SAD strains. This observation indicates that SAD contains not only cassette information coding for a1 (presumably from HMRa) but also sites for Sir action.  相似文献   

15.
A long-standing problem in ecology is to understand how the species–abundance distribution (SAD) varies with sampling scale. The problem was first characterized by Preston as the veil line problem. Although theoretical and empirical studies have now shown the nonexistence of the veil line, this problem has generated much interest in scaling biodiversity patterns. However, research on scaling SAD has so far exclusively focused on the relationship between the SAD in a smaller sampling area and a known SAD assumed for a larger area. An unsolved challenge is how one may predict species–abundance distribution in a large area from that of a smaller area. Although upscaling biodiversity patterns (e.g. species–area curve) is a major focus of macroecological research, upscaling of SAD across scale is, with few exceptions, ignored in the literature. Methods that directly predict SAD in a larger area from that of a smaller area have just started being developed. Here we propose a Bayesian method that directly answers this question. Examples using empirical data from tropical forests of Malaysia and Panama are employed to demonstrate the use of the method and to examine its performance with increasing sampling area. The results indicate that only 10-15% of the total census area is needed to adequately predict species abundance distribution of a region. In addition to species abundance distributions, the method also predicts well the regional species richness.  相似文献   

16.
The aim of this study is to investigate the rate of childhood traumatic experiences and assess the relationship between childhood trauma and impulsivity in the presence of attention deficit–hyperactivity disorder (ADHD) in patients with social anxiety disorder (SAD). A total of 123 patients with a primary diagnosis of SAD were enrolled. All patients were assessed by using the clinical version of Structured Clinical Interview for DSM-IV (SCID-I/CV) and Schedule for Affective Disorders and Schizophrenia for School Age Children—Present and Lifetime version (K-SADS-PL), ADHD module. A clinical and sociodemographic data form and rating scales were filled out. We found higher rates of emotional traumatic experiences and impulsivity along with more severe symptoms of depression, anxiety and social anxiety in the group of SAD patients with childhood ADHD than in SAD patients without ADHD in childhood. The presence of ADHD is associated with higher severity in several domains in patients with SAD. Patients with SAD should be assessed carefully whether they have ADHD, especially when their SAD symptoms are severe, when they have a history of traumatic experiences or problems with impulse control.  相似文献   

17.
M M Eldeib  C S Reddy 《Teratology》1990,41(2):137-146
Secalonic acid D (SAD) is a teratogenic mycotoxin that causes cleft palate in the offspring of treated pregnant mice. To investigate the role of maternal corticosterone in the teratogenicity of SAD, pregnant CD-1 mice were treated with 30 mg/kg of SAD i.p. on day 11 of pregnancy in either 5% (w/v) NaHCO3 or 20% (v/v) dimethyl sulfoxide (DMSO) in NaHCO3. Radioimmunoassay (RIA) was performed to determine plasma corticosterone at 24, 48, 72, and 96 hr after dosing. No interference by EDTA, SAD, DMSO, or pentobarbital was noticed on the RIA. Significant (P less than .01) elevations in plasma corticosterone concentrations were seen 24 and 48 hr following dosing of SAD in NaHCO3 with concentrations reaching a peak just prior to the onset of shelf elevation and fusion. Simultaneous treatment with DMSO, an agent known to antagonize the teratogenic effect of SAD, completely abolished the SAD-induced corticosterone elevation at the 24 hr time point and significantly (P less than .01) reduced it at the 48 hr time point. To evaluate the specificity of the role of corticosterone in the teratogenicity of SAD, plasma samples from mature males similarly treated with either single or multiple doses of SAD ranging from 15 to 45 mg/kg were assayed for corticosterone. A dose of SAD comparable to that used in the pregnant females failed to significantly change plasma corticosterone concentrations in the males. An elevation corresponding only to 75% of that in the females was seen in males receiving multiple doses of SAD totaling three times the dose used in the females. As with females, DMSO completely abolished plasma corticosterone elevation by SAD in the males. These results demonstrate, for the first time, the effect of SAD on a mammalian endocrine system and provide evidence for a specific involvement of elevated maternal plasma corticosterone concentrations in SAD teratogenicity.  相似文献   

18.
19.
Social anxiety disorder (SAD), characterized by fear of being scrutinized by others, has features that that are closely linked to the concept of shame. Despite this, it remains to be investigated whether shame is elevated in persons with SAD, and if cognitive behavior therapy (CBT) for SAD could reduce shame experience. In the present study, we focused on internal shame, i.e. the type of shame that pertains to how we judge ourselves. Although guilt is distinctly different from shame, we also viewed it as important to investigate its role in SAD as the two emotions are highly correlated. The aim of this study was to investigate: (I) if persons with SAD differ from healthy controls on shame and guilt, (II) if shame, guilt, depressive symptoms, and social anxiety are associated in persons with SAD, and (III) if CBT can reduce internal shame in patients with SAD. Firstly, we conducted a case-control study comparing a sample with SAD (n = 67) with two samples of healthy controls, a main sample (n = 72) and a replication sample (n = 22). Secondly, all participants with SAD were treated with CBT and shame, measured with the Test of Self-Conscious affect, was assessed before and after treatment. The results showed that shame was elevated in person with SAD compared to the control replication sample, but not to the main control sample. In addition, shame, social anxiety, and depressive symptoms were significantly associated among participants with SAD. After CBT, participants with SAD had significantly reduced their shame (Cohen''s d = 0.44). Guilt was unrelated to social anxiety. We conclude that shame and social anxiety are associated and that it is likely that persons with SAD are more prone to experience shame than persons without SAD. Also, CBT is associated with shame reduction in the treatment of SAD.  相似文献   

20.
A definite correlation has been found between the background EEG, the sensory afterdischarge (SAD) of the visual cortex and the nature of the animals' behaviour. Calmer rats with a well pronounced SAD exhibited activation of a certain type of hygienic movements, as fine differentiations were presented. As a rule, the movements were accompanied by EEG synchronization. At the same time positive conditioned reflexes persisted, in spite of an increased number of collisions. In restless animals, as the stress situation became stronger, forced movements appeared against the background of EEG desynchronization with a slightly pronounced SAD, alternating with numbness and stupor. Conditioned reflexes disappeared for several weeks. It has been assumed that relative retention of temporary connections in stress situations in animals with a well pronounced SAD is linked with the defensive-stabilizing nature of the inhibitory synchronized EEG rhythms.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号