Graph theoretical methods for comparing phytosociological structures

This paper describes some methods that can be used to compare the phytosociological structure of plant communities using some graph theoretic properties of the directed graphs that represent them. In such a graph, the species are represented by points and the association of species A with species B is represented by a directed line segment going from B to A. Two communities can be compared using simple indices to measure the similarity of their species-lists (point similarity) and of the species associations in them (line similarity). A more sophisticated and informative measure of line similarity is the probability that, given the number of points shared by two graphs, they have at least as many lines in common as they are observed to have. A formula for calculating that probability is given here. The graphs of community structure can also be compared with respect to the homogeneity of the distribution of the lines among the points, a property related to the number of species that are important in determining the composition of the community. These techniques are illustrated using the graphs of the phytosociological structure of intertidal seaweed communities on the southeast coast of Nova Scotia.Nomenclature follows: South and Cardinal (1970)     

Semantic couplets as an expression of cultural identity

Semantic couplets in the Nahuatl language can function as discourse markers that have the pragmatic function of building identities among speech communities. The subsistence of these linguistic structures in present day institutional discourses points to similarities, not only in social, religious but also in linguistic practices of speech communities that are distant in time. Semantic couplets are presented as evidence that links modern speech events with those from pre-Hispanic times.     

Speech graphs provide a quantitative measure of thought disorder in psychosis

Background

Psychosis has various causes, including mania and schizophrenia. Since the differential diagnosis of psychosis is exclusively based on subjective assessments of oral interviews with patients, an objective quantification of the speech disturbances that characterize mania and schizophrenia is in order. In principle, such quantification could be achieved by the analysis of speech graphs. A graph represents a network with nodes connected by edges; in speech graphs, nodes correspond to words and edges correspond to semantic and grammatical relationships.

Methodology/Principal Findings

To quantify speech differences related to psychosis, interviews with schizophrenics, manics and normal subjects were recorded and represented as graphs. Manics scored significantly higher than schizophrenics in ten graph measures. Psychopathological symptoms such as logorrhea, poor speech, and flight of thoughts were grasped by the analysis even when verbosity differences were discounted. Binary classifiers based on speech graph measures sorted schizophrenics from manics with up to 93.8% of sensitivity and 93.7% of specificity. In contrast, sorting based on the scores of two standard psychiatric scales (BPRS and PANSS) reached only 62.5% of sensitivity and specificity.

Conclusions/Significance

The results demonstrate that alterations of the thought process manifested in the speech of psychotic patients can be objectively measured using graph-theoretical tools, developed to capture specific features of the normal and dysfunctional flow of thought, such as divergence and recurrence. The quantitative analysis of speech graphs is not redundant with standard psychometric scales but rather complementary, as it yields a very accurate sorting of schizophrenics and manics. Overall, the results point to automated psychiatric diagnosis based not on what is said, but on how it is said.     

Graph topology plays a determinant role in the evolution of cooperation

We study the evolution of cooperation in communities described in terms of graphs, such that individuals occupy the vertices and engage in single rounds of the Prisoner's Dilemma with those individuals with whom they are connected through the edges of those graphs. We find an overwhelming dominance of cooperation whenever graphs are dynamically generated through the mechanisms of growth and preferential attachment. These mechanisms lead to the appearance of direct links between hubs, which constitute sufficient conditions to sustain cooperation. We show that cooperation dominates from large population sizes down to communities with nearly 100 individuals, even when extrinsic factors set a limit on the number of interactions that each individual may engage in.     

Cladistic analysis of languages: Indo-European classification based on lexicostatistical data

The phylogeny of the Indo‐European (IE) language family is reconstructed by application of the cladistic methodology to the lexicostatistical dataset collected by Dyen (about 200 meanings, 84 speech varieties, the Hittite language used as a functional outgroup). Three different methods of character coding provide trees that show: (a) the presence of four groups, viz., Balto‐Slavonic clade, Romano‐Germano‐Celtic clade, Armenian‐Greek group, and Indo‐Iranian group (the two last groups possibly paraphyletic); (b) the unstable position of the Albanian language; (c) the unstable pattern of the basalmost IE differentiation; but (d) the probable existence of the Balto‐Slavonic–Indo‐Iranian (“satem”) and the Romano‐Germano‐Celtic (+Albanian?) superclades. The results are compared with the phenetic approach to lexicostatistical data, the results of which are significantly less informative concerning the basal pattern. The results suggest a predominantly branching pattern of the basic vocabulary phylogeny and little borrowing of individual words. Different scenarios of IE differentiation based on archaeological and genetic information are discussed.     

Contributions of infant word learning to language development

Infants learn the forms of words by listening to the speech they hear. Though little is known about the degree to which these forms are meaningful for young infants, the words still play a role in early language development. Words guide the infant to his or her first syntactic intuitions, aid in the development of the lexicon, and, it is proposed, may help infants learn phonetic categories.     

广东森林群落排序分析

本文应用极点排序和位置向量排序的方法对广东13个森林群落进行排序分析,并分别用极点排序图和位置向量排序的二维图和三维图表示排序的结果。同时对排序图的生态学意义及排序方法的优缺点进行讨论。结果表明,三维位置向量排序图能较好地把性质相近的群落类型聚在一起,可作为植被分类的辅助方法;积点排序图从一定程度上反映了植被的连续变化;极点排序与位置向量排序虽然取得一定结果,但由于同属线性排序,损失的信息量较多,寻求非线性排序方法是研究的方向。     

Basic auditory processes involved in the analysis of speech sounds

This paper reviews the basic aspects of auditory processing that play a role in the perception of speech. The frequency selectivity of the auditory system, as measured using masking experiments, is described and used to derive the internal representation of the spectrum (the excitation pattern) of speech sounds. The perception of timbre and distinctions in quality between vowels are related to both static and dynamic aspects of the spectra of sounds. The perception of pitch and its role in speech perception are described. Measures of the temporal resolution of the auditory system are described and a model of temporal resolution based on a sliding temporal integrator is outlined. The combined effects of frequency and temporal resolution can be modelled by calculation of the spectro-temporal excitation pattern, which gives good insight into the internal representation of speech sounds. For speech presented in quiet, the resolution of the auditory system in frequency and time usually markedly exceeds the resolution necessary for the identification or discrimination of speech sounds, which partly accounts for the robust nature of speech perception. However, for people with impaired hearing, speech perception is often much less robust.     

对中国植物名称引入世界语的商榷

<正> 笔者在《世界语词源结构略析》一文中,曾提到中国植物名称引入世界语的问题,将另作论述。本文就是笔者根据近年来对千余种植物名称,就英、日、俄、拉及世界语等语种,进行文献调研,挑选其中约二百个中国常见植物的名称反复考察,发现在大多数资源植物中,几乎有一半属于药用植物。而它们的名称,近年来随着我国科技成果的推广,已经按汉语拼音在世界各国广泛应用,另有部分植物名称早年已为国外引用,至今仍在使用的。尚有部分在学名中有中国或中国某地方名的音译。对于这些植物名称引入世界语的问题,笔者在此提出个人的一些见解。     

Speech perception at the interface of neurobiology and linguistics

Speech perception consists of a set of computations that take continuously varying acoustic waveforms as input and generate discrete representations that make contact with the lexical representations stored in long-term memory as output. Because the perceptual objects that are recognized by the speech perception enter into subsequent linguistic computation, the format that is used for lexical representation and processing fundamentally constrains the speech perceptual processes. Consequently, theories of speech perception must, at some level, be tightly linked to theories of lexical representation. Minimally, speech perception must yield representations that smoothly and rapidly interface with stored lexical items. Adopting the perspective of Marr, we argue and provide neurobiological and psychophysical evidence for the following research programme. First, at the implementational level, speech perception is a multi-time resolution process, with perceptual analyses occurring concurrently on at least two time scales (approx. 20-80 ms, approx. 150-300 ms), commensurate with (sub)segmental and syllabic analyses, respectively. Second, at the algorithmic level, we suggest that perception proceeds on the basis of internal forward models, or uses an 'analysis-by-synthesis' approach. Third, at the computational level (in the sense of Marr), the theory of lexical representation that we adopt is principally informed by phonological research and assumes that words are represented in the mental lexicon in terms of sequences of discrete segments composed of distinctive features. One important goal of the research programme is to develop linking hypotheses between putative neurobiological primitives (e.g. temporal primitives) and those primitives derived from linguistic inquiry, to arrive ultimately at a biologically sensible and theoretically satisfying model of representation and computation in speech.     

Does Lateral Transmission Obscure Inheritance in Hunter-Gatherer Languages?

In recent years, linguists have begun to increasingly rely on quantitative phylogenetic approaches to examine language evolution. Some linguists have questioned the suitability of phylogenetic approaches on the grounds that linguistic evolution is largely reticulate due to extensive lateral transmission, or borrowing, among languages. The problem may be particularly pronounced in hunter-gatherer languages, where the conventional wisdom among many linguists is that lexical borrowing rates are so high that tree building approaches cannot provide meaningful insights into evolutionary processes. However, this claim has never been systematically evaluated, in large part because suitable data were unavailable. In addition, little is known about the subsistence, demographic, ecological, and social factors that might mediate variation in rates of borrowing among languages. Here, we evaluate these claims with a large sample of hunter-gatherer languages from three regions around the world. In this study, a list of 204 basic vocabulary items was collected for 122 hunter-gatherer and small-scale cultivator languages from three ecologically diverse case study areas: northern Australia, northwest Amazonia, and California and the Great Basin. Words were rigorously coded for etymological (inheritance) status, and loan rates were calculated. Loan rate variability was examined with respect to language area, subsistence mode, and population size, density, and mobility; these results were then compared to the sample of 41 primarily agriculturalist languages. Though loan levels varied both within and among regions, they were generally low in all regions (mean 5.06%, median 2.49%, and SD 7.56), despite substantial demographic, ecological, and social variation. Amazonian levels were uniformly very low, with no language exhibiting more than 4%. Rates were low but more variable in the other two study regions, in part because of several outlier languages where rates of borrowing were especially high. High mobility, prestige asymmetries, and language shift may contribute to the high rates in these outliers. No support was found for claims that hunter-gatherer languages borrow more than agriculturalist languages. These results debunk the myth of high borrowing in hunter-gatherer languages and suggest that the evolution of these languages is governed by the same type of rules as those operating in large-scale agriculturalist speech communities. The results also show that local factors are likely to be more critical than general processes in determining high (or low) loan rates.     

缙云山常绿阔叶林次生演替优势种群动态

本文用林木大小级分析了缙云山常绿阔叶林次生演替系列群落优势乔木种群密度动态。通过方差分析,用均方—区组图探讨优势种群分布格局动态,研究了种群增长、分布格局与群落演替的关系。通过对演替期间优势种群大小级密度、结构、存活曲线的分析,估计优势种群在演替系列群落中出现的顺序,从而分为演替森林先锋种、顶极先锋种和顶极种。大小级结构分析结果表明,白茅群丛只有Ⅰ、Ⅱ级苗木;马尾松林除V级大树外,为一倒金字塔形;针阔混交林与银木荷林具完整等级的典型金字塔形,栲树林的金字塔不规则。种群分布格局随演替进程而变化,但主要表现为集群分布。以K值判断,顶极群落优势种群集聚度低于混交林。演替期间,种群个体格局规模增大。环境格局变化相应于分布格局而变化,如马尾松种群,规模增加强度下降,如银木荷,或规模强度都增加,如白毛新木姜子。     

Evidence of structural balance in spatial ecological networks

Despite recent advances in applying networks to study ecological systems, most of the network datasets are built attending only to a single type of interaction between nodes, which can be an oversimplification. In the present work, we built ecological networks that had positive and negative links for multiple plant communities based on the local spatial association between species. Then, we evaluated whether those networks were in balance, a hypothesis commonly formulated for real signed graphs but never tested in systems other than social networks. Specifically, we quantified the global and the local structural balance in the networks. We found that plant community networks were more balanced than expected by chance, and that this pattern was due to a large number of balanced triads to the detriment of unbalanced ones. Furthermore, this pattern was consistent among all of the types of the plant communities examined, which suggests that configurations that promote structural balance might be common in ecological signed networks. We also found that almost all networks had some unbalanced components, which might be responsible for the adaptation of the system. Mechanisms behind these structure and possible applications for community ecology are discussed. Our results encourage testing structural balance in other ecological networks to confirm if it is a widespread architecture of natural systems.     

Dynamics of formation of internal lexicon in junior school children

Study of lexicon has shown that the verbal-thinking activity did not yet acquired the automatic character in school-children of 1–2 grades; predominant are nouns that reflect the graphic-sensory world picture. Such world picture represents the near space of the child with emphasis of interior of the class and apartment. This period is suggested to be due to predominance of activity of the right hemisphere. In the 9–10-year-old children, as compared with the 7–8-year-old children, the lexicon is distinguished by automatic character of the speech flow, an increase of the number of verbs, adjectives, and proper nouns, by the appearance of the wide circle of associations, by the presence of conceptual lexicon, and by the appearance of the word-substituting and word-forming associates and dual oppositions indicating development of abstract thinking. This is suggested to be the beginning of the ontogenetically late stage of the verbal-thinking activity associated with an increase of activity of the left hemisphere.Translated from Zhurnal Evolyutsionnoi Biokhimii i Fiziologii, Vol. 40, No. 5, 2004, pp. 436–440.Original Russian Text Copyright © 2004 by Nikolaenko.To the 100-Anniversary of N. N. Traugott     

Bantu language trees reflect the spread of farming across sub-Saharan Africa: a maximum-parsimony analysis

Linguistic divergence occurs after speech communities divide, in a process similar to speciation among isolated biological populations. The resulting languages are hierarchically related, like genes or species. Phylogenetic methods developed in evolutionary biology can thus be used to infer language trees, with the caveat that 'borrowing' of linguistic elements between languages also occurs, to some degree. Maximum-parsimony trees for 75 Bantu and Bantoid African languages were constructed using 92 items of basic vocabulary. The level of character fit on the trees was high (consistency index was 0.65), indicating that a tree model fits Bantu language evolution well, at least for the basic vocabulary. The Bantu language tree reflects the spread of farming across this part of sub-Saharan Africa between ca. 3000 BC and AD 500. Modern Bantu subgroups, defined by clades on parsimony trees, mirror the earliest farming traditions both geographically and temporally. This suggests that the major subgroups of modern Bantu stem from the Neolithic and Early Iron Age, with little subsequent movement by speech communities.     

Language development: breaking the code

This paper reviews the major achievements of the preschool years regarding language acquisition. Although most children appear to master their native language with little apparent effort, learning a language is a complex task. It requires the ability to extract clues from environmental stimuli and to discover how those stimuli convey meanings and are modified according to the meaning conveyed. In general, language learning follows a similar sequence regardless of the language being learned. The major accomplishments in the areas of speech perception, early sound production, phonology, lexicon, syntax, and morphology are described, with specific examples from recent studies of acquisition of French in young children from Québec. These examples confirm major milestones observed in other languages, but also illustrate how comparisons across languages and across children learning the same language can be challenging. For each area, current issues are identified regarding the bases (neurological, genetic) of language development, as well as the processes (social, cognitive, linguistic) involved. Current hypotheses regarding language acquisition and language disorders are briefly discussed.     

Linguistic Syncretism and Language Ideologies: Transforming Sociolinguistic Hierarchy on Rapa Nui (Easter Island)

Recent work in linguistic anthropology highlights the role of linguistic ideologies, or cultural conceptions of language, in transforming social relations and linguistic structure and use. This article examines the links between language attitudes and uses in their institutional and interactional contexts on Rapa Nui, a Polynesian island community that is part of the Chilean nation-state. By the 1970s, a sociolinguistic hierarchy and functional compartmentalization of languages between Spanish and Rapa Nui—what I will describe as "colonial diglossia"—had become established in the community, which was rapidly becoming bilingual. Language shift toward Spanish has continued to advance since then. However, rising Rapa Nui syncretic language practice and consciousness, combined with the political successes of a local indigenous movement and changes in the local economy, are now contributing to the breakdown of colonial diglossia, generating better conditions for the maintenance of the Rapa Nui language.     

Netgram: Visualizing Communities in Evolving Networks

Real-world complex networks are dynamic in nature and change over time. The change is usually observed in the interactions within the network over time. Complex networks exhibit community like structures. A key feature of the dynamics of complex networks is the evolution of communities over time. Several methods have been proposed to detect and track the evolution of these groups over time. However, there is no generic tool which visualizes all the aspects of group evolution in dynamic networks including birth, death, splitting, merging, expansion, shrinkage and continuation of groups. In this paper, we propose Netgram: a tool for visualizing evolution of communities in time-evolving graphs. Netgram maintains evolution of communities over 2 consecutive time-stamps in tables which are used to create a query database using the sql outer-join operation. It uses a line-based visualization technique which adheres to certain design principles and aesthetic guidelines. Netgram uses a greedy solution to order the initial community information provided by the evolutionary clustering technique such that we have fewer line cross-overs in the visualization. This makes it easier to track the progress of individual communities in time evolving graphs. Netgram is a generic toolkit which can be used with any evolutionary community detection algorithm as illustrated in our experiments. We use Netgram for visualization of topic evolution in the NIPS conference over a period of 11 years and observe the emergence and merging of several disciplines in the field of information processing systems.     

Social variation in Shoshoni phonology: An ecological interpretation

Under certain environmental and social conditions, intensive dialect borrowing can yield situations in which alternate phonemes may occur with such frequency in items elicited within a single speech community as to give the appearance of free variation. Such social variation, in which members of a single speech community utilize different reflexes of the same historic phoneme within their own vocabulary — thereby creating a superficial impression of free variation within the community — occurs within Shoshoni phonology.     

The self-organization of speech sounds

The speech code is a vehicle of language: it defines a set of forms used by a community to carry information. Such a code is necessary to support the linguistic interactions that allow humans to communicate. How then may a speech code be formed prior to the existence of linguistic interactions? Moreover, the human speech code is discrete and compositional, shared by all the individuals of a community but different across communities, and phoneme inventories are characterized by statistical regularities. How can a speech code with these properties form? We try to approach these questions in the paper, using the "methodology of the artificial". We build a society of artificial agents, and detail a mechanism that shows the formation of a discrete speech code without pre-supposing the existence of linguistic capacities or of coordinated interactions. The mechanism is based on a low-level model of sensory-motor interactions. We show that the integration of certain very simple and non-language-specific neural devices leads to the formation of a speech code that has properties similar to the human speech code. This result relies on the self-organizing properties of a generic coupling between perception and production within agents, and on the interactions between agents. The artificial system helps us to develop better intuitions on how speech might have appeared, by showing how self-organization might have helped natural selection to find speech.