Co-occurrence patterns of cavity-nesting birds in cottonwood-willow communities

Summary We studied the covariation of six species of cavity-nesting birds to determine the extent to which species' co-occurrence patterns were attributable to interspecific relations. We tested two null hypotheses: (1) inverse relations did not exist among potential competitors for nest trees or nest cavities, and (2) there were no positive relations among potential commensals for nest cavities. Statistical power analyses, and simple, partial, and multiple partial correlation and regression analyses provided little evidence of species-species or higher-order inverse or positive relations. Most of the variation in co-occurrence patterns was associated with stand characteristics. Collectively, an abundance of nest trees and nest cavities, differences among species in acceptable nest-tree and nest-cavity dimensions, and different periods of peak nesting activity appear to be responsible for the lack of negative relations among potential competitors. Positive relations among potential commensals were weak presumably because (1) secondary cavity nesters (SCNs) frequently used cavities that originated from wind-, lightning-, and/or disease-damaged limbs and were thus not dependent completely on primary cavity nesters for cavities, and (2) the lag time for cavity use by SCNs is often two or more seasons. Interspecific relations were apparently not major determinants of community structure during our investigation; assemblages of cavity nesters appeared instead to be influenced more by independent species-specific habitat responses.     

The Relational Basis of Molecular Codes

Molecular codes can be considered a special type of mapping among molecular species in biochemical systems. The formalization of molecular codes allows to identify these in network models of real world systems. Analyzing algorithmically identified codes leads to the observation that codes does not necessarily stand alone, but that we can identify certain relations among codes. In this paper I will define two types of relations that can occur among codes, (1) code linkage and (2) code nesting, and will discuss implications of this finding.     

AFLP 引物组合数量对准确研究竹子系统关系的影响

利用AFLP技术对26个竹子种类进行了多样性分析, 以探索引物组合数量对准确研究竹子类群系统关系的影响。实验共随机选取10对AFLP引物, 并对所得10组AFLP标记数据随机组合后进行Nei氏遗传距离/UPGMA聚类分析。每对AFLP引物 扩增数据为一组, 随着用于聚类统计的AFLP标记数据随机组合数量的增加, 26个竹子种类的聚类关系趋向一致。这提示我们,在系统学研究中, 足够数量的引物组合是获得供试材料间准确聚类关系的基础, 应采用对各AFLP引物组合数据随机累加后进行聚类分析的方法, 以聚类关系为标准来确定用于分析供试品种的最少引物组合数量。     

Intertroop relations of chacma baboon (Papio ursinus)

Intertroop relations among four troops of the chacma baboon population on the Suikerbosrand Nature Reserve, southern Transvaal, South Africa, were studied for 18 months using radiotelemetry. Encounters between troops occurred only rarely and were relatively nonantagonistic in character. Dominance among the four troops was difficult to identify by means of behavior although differences in range quality among the four were marked. The way in which intertroop relations affected the fitness of members of each of the troops was, therefore, unclear. Transfer of individuals from one troop to another was easily accomplished by both males and females and probably negated the effects of differential range quality on individual reproductive fitness.     

Interannual variation in bird–landscape relations: understanding sources of a pervasive conservation dilemma

Interannual variation in bird–landscape relations is pervasive, and it generates decision dilemmas for conservationists who use such relations to support landscape-level planning, acquisition and management. Interannual variation occurs in two ways. Model consistency refers to agreement among years in the variables and directions of relations in a model for a species. R² consistency measures variation in the strengths of association between bird and landscape variables for a species among years. We examined how distributional and biological traits of species, model-selection certainty (likelihood the best model was selected in a given year), and model complexity (number of landscape variables) were associated with interannual variation in bird–landscape relations for 72 species in the Appalachian Mountains, USA. Abundant, narrowly distributed species, and cavity nesters exhibited higher model consistency, but model-selection certainty, not species' traits or model complexity, had the most influence on model and R² consistency. Increasing model-selection certainty by improving sampling methods and model-selection strategies may be the most effective way to cope with interannual variation in bird–landscape relations.     

Relations among variations in human red cell volume,density, membrane area,hemoglobin content and cation content

It is shown how variations in different properties of red cells can be inter-related provided relations exist among these properties at the single cell level. On the basis of the cell density dependence on cell volume and hemoglobin content, and the assumed volume dependence on red cell cation and hemoglobin content, nine relations among the variations in red cell volume, density, membrane area, hemoglobin content and cation content, and their correlations are derived. Values of seven correlation coefficients are theoretically predicted and are shown to be consistent with the experiments performed by density fractionated red blood cells. The cell volume dependence on cation and hemoglobin content obtained from relations among variations is compared with the predictions obtained by the existing model about the osmotic behavior of the red blood cell. Furthermore, it is shown that data on the variations of the red cell properties indicate the existence of the relation among cation content, hemoglobin content, and membrane area at the level of a single cell.     

Ritual production of environmental history among the Arawakan Wakuénai of Venezuela

This essay examines ritual and ceremonial activities among the Arawakspeaking Wakuénai of the Venezuelan Amazon as processes of constructing power relations in changing historical and ecological conditions. Ritual evocations of the vertical dimension of power relations between mythic ancestors and human descendants adapt local populations to conditions of relatively severe stress, such as epidemics and scarcity of fish in long wet seasons. Other rituals evoke the horizontal dimension of power relations between affinally-related groups as a way of expanding the local descent group in conditions of lowered stress. These two ways of exercising ritual power link human populations to specific natural habitats and provide flexibility needed to adjust to demographic and other historical changes. Through ritual performances, the Wakuénai transform the natural environment into a cultural landscape of socialized objects and, conversely, remember the history of political relations among peoples through spirit-naming of natural species, objects, places, and geographic landmarks.     

Agonistic Interactions of Juvenile Savanna Baboons

19 juvenile members of known genealogies in two wild baboon groups were studied over a 16-month period to compare the ontogeny of agonistic experience and dominance relations for males and females. Juveniles of all age-sex classes were disproportionately likely to receive aggression from and submit to adult males per unit of time spent in proximity. This pattern intensified with increasing juvenile age. With age, juvenile females more often submitted to unrelated adult females from higher-ranking families, whereas this was not true for juvenile males. All juveniles received aggression from older group members more often during feeding than was expected by chance. High rates of agonistic interaction with unrelated adult females accounted for old juvenile females (3–5.5 years-old) interacting agonistically more frequently than male age peers and young juveniles of either sex (1–2.5 years-old). Adult females were also more aggressive toward females among young juveniles, suggesting that adult females target females among juveniles for aggression and resistance to rank reversal. Within juvenile age groups, males dominated all females and all younger males, irrespective of maternal dominance status. Dominance relations among female age-peers were generally isomorphic with relations among their mothers. No juvenile targeted any older male for rank reversal. Males targeted all older females, whereas females typically targeted only older females from families lower-ranking than their own. The strong sexual dimorphism in adult body size in baboons may explain why juvenile males' dominance relations with peers and adult females are not structured along lines of family membership as is true for the less dimorphic macaques. Acquisition of higher agonistic status probably allows juveniles of both sexes to increase their success in within-group feeding competition during late stages of juvenility, which, in turn, could affect important life-history traits such as age at menarche and adult body size.     

Social behavior of the pygmy chimpanzees

The affinitive interactions among the pygmy chimps seem to be the most frequent in the male/female combination, next in the female/female, and the least frequent in the male/male. The differences of frequencies among the combinations, however, are little, and it may be said that the pygmy chimps are not so much biased by sex in the affinitive relations. Their aggressive behavior is mild, and their behavior in general shows high tolerance, especially between different sexes and among females. Similar tendency is also seen in grouping (Kuroda, 1979). Therefore, the pygmy chimp’s society may be said to be integrated by the male/female affinity, little differentiated by sex in the grouping and the affinitive relations, and with high inter-individual tolerance and coherence.     

Cultural Variations on Gender: Latin American Marianismo/Machismo in Australia

This paper concerns cultural and social ideas and practices on gender differences among Latin American immigrants in Australia. It explores the ways in which immigrants' notions of gender relations expressed as marianismo/machismo generated in their societies of origin, influence the social gender relationships among the settlers in Australia. The argument is that marianismo/machismo are ideological constructs which reinforce woman's oppression and at the same time help to perpetuate social relations of inequality between men and women.     

根据叶解剖特征试论赖草属及其相关类群间的亲缘关系

通过叶片的解剖观察,以表型系统学的原理和方法,对赖草属及其相关类群的亲缘关系进行了分析。在横切面上,赖草属及其相关6个属的结构虽然均属于狐茅型,但在各类群之间存在差异。其中,披碱草属与赖草属含有最大数量的相同性状,与赖草属的亲缘关系最近;新麦草属和偃麦草属均与赖草属的相同性状较少,该2属仅稍接近于赖草属;而大麦属、芒麦草属和鹅观草属与赖草属的相同性状更少,则此3属与赖草属的亲缘关系也相对疏远。同时,本文还对其它6属间的亲缘关系作了进一步探讨,绘制了整个7属的亲缘关系示意图,并与其外部形态特征作了对应比较,从而弥补了过去研究的不足。     

The population ecology of male gametophytes: the link between pollination and seed production

The fate of male gametophytes after pollen reaches stigmas links pollination to ovule fertilisation, governing subsequent siring success and seed production. Although male gametophyte performance primarily involves cellular processes, an ecological analogy may expose insights into the nature and implications of male gametophyte success. We elaborate this analogy theoretically and present empirical examples that illustrate associated insights. Specifically, we consider pollen loads on stigmas as localised populations subject to density‐independent mortality and density‐dependent processes as they traverse complex stylar environments. Different combinations of the timing of pollen‐tube access to limiting stylar resources (simultaneous or sequential), the tube distribution among resources (repulsed or random) and the timing of density‐independent mortality relative to competition (before or after) create signature relations of mean pollen‐tube success and its variation among pistils to pollen receipt. Using novel nonlinear regression analyses (two‐moment regression), we illustrate contrasting relations for two species, demonstrating that variety in these relations is a feature of reproductive diversity among angiosperms, rather than merely a theoretical curiosity. Thus, the details of male gametophyte ecology should shape sporophyte reproductive success and hence the dynamics and structure of angiosperm populations.     

Growth, delayed fluorescence and pigment composition of four Prorocentrum minimum strains growing at two salinities

Prorocentrum minimum is a potentially harmful and widely distributed marine dinoflagellate. Several P. minimum strains have already been studied, showing phylogenetical relations of strains isolated from the same geographical regions. Similarity among the strains was further examined on the basis of their physiology. Pigment composition and concentration, as well as delayed fluorescence (DF) decay kinetics and intensity, were measured in four P. minimum strains isolated from the Baltic and Adriatic Seas. The strains were grown at two salinities characteristic of the Baltic (8 PSU) and North Adriatic Seas (32 PSU). Strain differences in DF decay kinetics and growth did not always follow their genetic relations. While two strains showed similarities to the previously described strains from the Baltic and Adriatic Seas in DF parameters, the other two strains seemed to be specific. The differences among strains isolated from the same sea could stem from adaptations to conditions in the specific habitats. Cluster analysis based on the ratio of individual carotenoid pigments concentrations to the chlorophyll a concentration or to total carotenoids were not conclusive in showing relations among the strains. Among the measured pigments, only peridinin concentration depended on salinity in all st.     

A contribution to the mathematical biophysics of psychophysical discrimination II

The properties of a neural mechanism previously discussed are given in more general form. It is shown that, under certain conditions, a psychophysical scale value is proportional to a difference between excitation factors at a synapse. More general relations are derived which hold among different variables in the two and three categories of judgment. An attempt is made to apply the results to the method of choices. Certain relations derived are compared with available experimental data.     

Numerical Classification of Bacteria

It has been suggested by Sokal and Sneath that the mathematical techniques used in numerical taxonomy would effectively be applied to elucidate serological (and perhaps phylogenetic) relations among organisms. This excellent idea, however, has hitherto never come into operation. The present paper describes a mathematical method for analyzing the intensities of antigen-antibody reactions between test organisms to make clear their serological relations. Eighteen corynebacteria were examined as a test case, and a brief discussion is presented on the results obtained.     

Formal modeling of approximate relations in biochemical systems

Aiming to satisfy the need for the formalization of semiquantitative reasoning in the analysis of biochemical systems, the O[M] formalism for reasoning with orders of magnitude and approximate relations has been developed. It is based on seven primitive relations among quantities and compound relations which are formed as implicit disjunctions of primitives. O[M] can perform inferences by using formal approximate relations, algebraic equations, inequalities, if-then rules, assumptions, and goals. The applications discussed include Michaelis-Menten kinetics, different modes of inhibition of an enzymatic reaction, analysis of fluxes in biochemical networks, and identification of rate-limiting steps of biochemical pathways. In these applications, O[M] provides a medium for acquisition and formalization of previously informal concepts, analysis of systems at the order-of-magnitude level of detail, and automation of commonsense reasoning.     

Molecular phylogenetic study on the origin and evolution of Mustelidae

The family Mustelidae, which consists of Mustelinae, Lutrinae, Melinae, and Taxidiinae, is the largest family among Carnivora and is a highly diverse group. Recent molecular phylogenetic studies have clarified the phylogenetic relations among Mustelidae, but there remain several unresolved problems, particularly concerning the deep branchings. Whereas many studies support the monophyly of Mustelidae+Procyonidae among Musteloidea, the relations between Mustelidae+Procyonidae, Ailuridae, and Miphitidae are still unclear. To address these problems, we inferred a tree on the basis of the sequences of mitochondrial genomes and of multiple nuclear genes using the maximum likelihood method. Our results strongly support the hypothesis that the Taxidiinae branched at first, followed by the branching of the Melinae. After that, Mustelinae diversified, and Lutrinae evolved within Mustelinae. With respect to the deep branchings in Musteloidea, the Ailuridae/Mephitidae monophyly tree and the Mephitidae-basal tree are indistinguishable in log-likelihood score, and this problem remains unresolved.     

不同地理种源云南红豆杉的遗传多样性与紫杉醇含量相关性分析

应用AFLP和HPLC方法研究了云南红豆杉（Taxus wallichiana var．wdlwhiana）的遗传多样性与紫杉醇含量之间的关系。AFLP指纹图谱显示7个居群谱带明显分为两种式样。PopGenel．31和Arlequin3．1软件分析结果表明：云南红豆杉居群内遗传比较稳定,居群间遗传分化极其显著（L=0．67）。测定当年生小枝叶紫杉醇含量结果表明：紫杉醇含量在居群间和居群内个体差异都较大。天然林中潞西居群的紫杉醇平均含量为0．0185％;腾冲和永德居群的紫杉醇含量比较低,分别为0．0049％和0．0087％;禄丰栽培居群紫杉醇含量比较高,平均为0．0225％。在居群水平上,遗传多样性和紫杉醇含量有一定程度的关联,但在个体水平上明显无对应关系。