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Hydrogen is troublesome in any periodic table classification. This being so it may as well be placed in a position that confers desirable attributes to the arrangement of the elements, while notionally recognising its lineage to the group 1 alkali metals and the group 17 halogens. Since the noble gases bridge the halogens and the alkali metals, and hydrogen encompasses the transition from the alkali metals to the halogens, there is more to the idea of hydrogen over helium. Hydrogen...seems to claim an exceptional position (Meyer 1870, p. 357) The real voyage of discovery consists not in seeking new lands but in seeing with new eyes (Proust 1927, p. 559) [ABSTRACT FROM AUTHOR]

Many studies on buyer–supplier-supplier triads demonstrate the value of the interactions between three business actors instead of two for identifying triadic collaboration strategies that can lead firms to improve their performance. However, there is little research to date that has explored which specific lean improvements the various types of buyer–supplier-supplier triads lead to. This paper fills this gap. We study an automotive supplier manufacturing company (the buyer) and its seven types of buyer–supplier-supplier triads emerging from the buyers' attempt to implement zero-defect manufacturing (ZDM) in the production process of a crash management system. The case study shows how a buyer manages their first-tier suppliers through three types of closed buyer–supplier-supplier triads, where all three actors collaborate to work for the common goal of ZDM. The case also shows four additional types of open triads, where the buyer relies on the first-tier supplier to manage the second-tier supplier without directly interacting with the latter. The paper discusses what types of triads in the case study seem to be associated with the buyers' efforts to achieve the following lean sub-goals of ZDM: full automation, production line flexibility, product flexibility, low cost, low defect rate, short cycle time, and minimum quality control. Finally, we also analyze the role of geographic proximity between the actors in open and closed buyer–supplier-supplier ZDM triads. [ABSTRACT FROM AUTHOR]

Partner choice promotes competition among individuals to be selected as a cooperative partner, a phenomenon referred to as competitive altruism. We explored whether chimpanzees engage in competitive altruism in a triadic Ultimatum Game where two proposers can send offers simultaneously or consecutively to a responder who can only accept one of the two competing offers. In a dyadic control condition only one proposer at a time could send an offer to the responder. Chimpanzees increased their offers across trials in the competitive triadic, but not in the dyadic control condition. Chimpanzees also increased their offers after being rejected in previous triadic trials. Furthermore, we found that chimpanzees, under specific conditions, outcompete first proposers in triadic consecutive trials before the responder could choose which offer to accept by offering more than what is expected if they acted randomly or simply offered the smallest possible amount. These results suggest that competitive altruism in chimpanzees did not emerge just as a by-product of them trying to increase over previous losses. Chimpanzees might consider how others' interactions affect their outcomes and engage in strategies to maximize their chances of being selected as cooperative partners. [ABSTRACT FROM AUTHOR]

Android is now one of the most popular operating systems in the world because of its open source character, so the threshold for hackers to make malware has also become lower, and more and more malware has started to threaten people's lives. Graphs are used to represent the program's syntactic and semantic structure, and can naturally represent malicious behavior, so we propose a malware detection method named SFCGDroid, which based on sensitive function call graph, so we propose a malware detection method named SFCGDroid, which based on sensitive function call graph. We first decompile the Android application to generate a function call graph (FCG), and extract the sensitive function call graph (SFCG) on the FCG. Secondly, we extract two class features (1) use the Skip-gram model to obtain function embeddings, and (2) treat the SFCG as a social network and extract the triads attribute of the sensitive API. The two types of features are combined as a feature representation of the SFCG and fed into a graph convolutional network (GCN) for malware detection. For experiments on 26,939 Android software datasets, SFCGDroid in this paper can achieve 98.22% accuracy and 98.20% F1 score. [ABSTRACT FROM AUTHOR]

Phenomenology is the unity of principles and methods employed for investigating the essence of things. The present paper is a brief review of the series of publications that these authors carried out over the past decade. The general thrust of these publications consists in the idea that phenomenological ideas of physics are used to analyze earthquakes. One conspicuous example of a phenomenological theory is thermodynamics. Maxwell's electrodynamics is also a perfect example of a phenomenological theory. The phenomenology of earthquakes is still far from reaching that high level of excellence. A look at the rational knowledge of geodynamics shows that we have so far reached a preliminary stage where we are aware of the subject-matter, methods, and problems faced by the future phenomenological theory of earthquakes. Nevertheless, we already clearly see that our approach to the construction of such a theory has promise. We are using concrete examples to show that phenomenological concepts of general physics are helpful in the search for the principles of the theory, in the processing and analysis of concrete manifestations of seismicity. [ABSTRACT FROM AUTHOR]

Background: sFLT-1 has been implicated in the pathogenesis of HDP. We aimed to examine the role of maternal and fetal polymorphisms in risk of HDP and severe-spectrum disease.Cases of HDP (143) and controls (169) from mother-baby dyads were recruited at the Los Angeles County Women’s and Children’s Hospital (WCH). Cases of severe disease (99) and controls (31) from mother-father-baby triads were recruited through HELLP syndrome websites. Four sFLT-1 SNPs (rs7993594, rs3751395, rs7983774, and rs664393) were genotyped. Data was analyzed using a log-linear regression model in the Haplin package in R.Maternal double dose of the A allele (rs7993594) exhibited a nominally significant increased risk of HDP (RR = 3.52, 95% CI 1.08, 11.20). In the severe-spectrum cohort, a marginally significant protective effect among mothers carrying infants with a single dose of the A allele (rs7993594) was observed (RR = 0.59, 95% CI 0.36, 0.98) and double-dose maternal carriage of the G-t-G-G haplotype increased risk of severe disease (RR = 4.13, 95% CI 1.22, 13.80).The maternal rs7993594 A allele appears to be associated with increased risk of HDP. Double-dose maternal carriage of the G-t-G-G haplotype increased risk of severe disease whereas the fetal rs7983774 A allele appears to be associated with decreased risk.Methods: sFLT-1 has been implicated in the pathogenesis of HDP. We aimed to examine the role of maternal and fetal polymorphisms in risk of HDP and severe-spectrum disease.Cases of HDP (143) and controls (169) from mother-baby dyads were recruited at the Los Angeles County Women’s and Children’s Hospital (WCH). Cases of severe disease (99) and controls (31) from mother-father-baby triads were recruited through HELLP syndrome websites. Four sFLT-1 SNPs (rs7993594, rs3751395, rs7983774, and rs664393) were genotyped. Data was analyzed using a log-linear regression model in the Haplin package in R.Maternal double dose of the A allele (rs7993594) exhibited a nominally significant increased risk of HDP (RR = 3.52, 95% CI 1.08, 11.20). In the severe-spectrum cohort, a marginally significant protective effect among mothers carrying infants with a single dose of the A allele (rs7993594) was observed (RR = 0.59, 95% CI 0.36, 0.98) and double-dose maternal carriage of the G-t-G-G haplotype increased risk of severe disease (RR = 4.13, 95% CI 1.22, 13.80).The maternal rs7993594 A allele appears to be associated with increased risk of HDP. Double-dose maternal carriage of the G-t-G-G haplotype increased risk of severe disease whereas the fetal rs7983774 A allele appears to be associated with decreased risk.Results: sFLT-1 has been implicated in the pathogenesis of HDP. We aimed to examine the role of maternal and fetal polymorphisms in risk of HDP and severe-spectrum disease.Cases of HDP (143) and controls (169) from mother-baby dyads were recruited at the Los Angeles County Women’s and Children’s Hospital (WCH). Cases of severe disease (99) and controls (31) from mother-father-baby triads were recruited through HELLP syndrome websites. Four sFLT-1 SNPs (rs7993594, rs3751395, rs7983774, and rs664393) were genotyped. Data was analyzed using a log-linear regression model in the Haplin package in R.Maternal double dose of the A allele (rs7993594) exhibited a nominally significant increased risk of HDP (RR = 3.52, 95% CI 1.08, 11.20). In the severe-spectrum cohort, a marginally significant protective effect among mothers carrying infants with a single dose of the A allele (rs7993594) was observed (RR = 0.59, 95% CI 0.36, 0.98) and double-dose maternal carriage of the G-t-G-G haplotype increased risk of severe disease (RR = 4.13, 95% CI 1.22, 13.80).The maternal rs7993594 A allele appears to be associated with increased risk of HDP. Double-dose maternal carriage of the G-t-G-G haplotype increased risk of severe disease whereas the fetal rs7983774 A allele appears to be associated with decreased risk.Conclusion: sFLT-1 has been implicated in the pathogenesis of HDP. We aimed to examine the role of maternal and fetal polymorphisms in risk of HDP and severe-spectrum disease.Cases of HDP (143) and controls (169) from mother-baby dyads were recruited at the Los Angeles County Women’s and Children’s Hospital (WCH). Cases of severe disease (99) and controls (31) from mother-father-baby triads were recruited through HELLP syndrome websites. Four sFLT-1 SNPs (rs7993594, rs3751395, rs7983774, and rs664393) were genotyped. Data was analyzed using a log-linear regression model in the Haplin package in R.Maternal double dose of the A allele (rs7993594) exhibited a nominally significant increased risk of HDP (RR = 3.52, 95% CI 1.08, 11.20). In the severe-spectrum cohort, a marginally significant protective effect among mothers carrying infants with a single dose of the A allele (rs7993594) was observed (RR = 0.59, 95% CI 0.36, 0.98) and double-dose maternal carriage of the G-t-G-G haplotype increased risk of severe disease (RR = 4.13, 95% CI 1.22, 13.80).The maternal rs7993594 A allele appears to be associated with increased risk of HDP. Double-dose maternal carriage of the G-t-G-G haplotype increased risk of severe disease whereas the fetal rs7983774 A allele appears to be associated with decreased risk. [ABSTRACT FROM AUTHOR]

The article begins with a response to a recent contribution by Jensen, in which he has criticized several aspects of the use of triads of elements, including Döbereiner's original introduction of the concept and the modern use of atomic number triads by some authors including myself. Such triads are groups of three elements, one of which has approximately the average atomic weight of the other two elements, as well as having intermediate chemical reactivity. I also examine Jensen's attempted reconstruction Mendeleev's use of triads in predicting the atomic weights of three hitherto unknown elements, that were subsequently named gallium, germanium and scandium. The present article then considers the use of atomic number triads, in conjunction with the phenomenon of first member anomaly, in order to offer support for Janet's left-step periodic table, in which helium is relocated into group 2 of the table. Such a table features triads in which the 2nd and third elements of each group, without fail, fall into periods of equal length, a feature that is absent in the conventional 18-column or the conventional 32-column table. The dual sense of the term element, which is the source of much discussion in the philosophy of chemistry, is alluded to in further support of such a relocation of helium that may at first appear to contradict chemical intuition. [ABSTRACT FROM AUTHOR]

In the last decade, the notion of triad was reintroduced by Eric Scerri, who suggested it as a possible categorical criterion to represent chemical periodicity. In particular, he reformulated the notion of triad in terms of atomic number instead of atomic weights; in this way, the value of the intermediate term of the triad became the exact average of the values of the two extremes. Following the inspiration of Scerri’s work, the main purpose of this article is to obtain a representation where all the relations among the chemical elements that form the groups of the periodic system can be reconstructed on the basis of triads, without using electronic configurations. [ABSTRACT FROM AUTHOR]

Despite an increasing number of studies, there is still a lack of knowledge about the unique features that underlie the process in equine assisted social work (EASW). This study aimed to reveal, through qualitative methods, the dyads within the triad that become stronger during the process of EASW, as well as the effect of the participation of the horse on the relationship between the counselor and client. Data were collected through in-depth interviews with nine female self-harming clients aged 15-21 years and eight staff members. The interviews, together with video-recorded human-horse interactions with three staff members and four clients were analyzed, resulting in additional issues answered by these three staff members and four clients in a second interview. Critical dialogues between patterns and fragmentations in the narratives and video-recordings, as well as a dialogue with the participants while they were viewing videos of their own EASW sessions, led to the conclusion that adding a horse qualitatively changes therapeutic relationships in EASW. The different triads consist of different liaisons between actors in the triad, giving rise to unique combinations. The quality of the relationships depends on both the staff and the clients' attachment orientations. Further research is needed to investigate how the degree of emotional connection to the horse affects the impact that horses have on triads in EASW. [ABSTRACT FROM AUTHOR]

All ethnic groups have norms and values according to which one is expected to behave. Immigrants in particular have personal networks that simultaneously consist of co-ethnics and friends of a different ethnic background. As a consequence, they may be accustomed to the behavior, norms, and values of their own ethnic group, and also be expected to behave according to those of another ethnic group. This may either lead to ego-gratification and the strengthening and enrichment of their personality, or to feelings of stress and non-acceptance if they cannot behave fully in accordance with the expectations of their friends. This study addresses the association between interethnic open triads in networks (i.e., brokerage) and individual psychological well-being. That is, we examine whether having intra-ethnic and interethnic relationships with friends who are not also friends with each other, is either positively or negatively associated with psychological well-being. Using (network) data from a large sample (N = 2,942; age = 19) of native Swedes and first- and second-generation immigrants from former Yugoslavia and Iran (all born in 1990 and currently living in Sweden), we show that interethnic brokerage is negatively associated with psychological well-being, which implies that the different norms, values and corresponding behaviors that prevail in different ethnic groups to which the ethnic broker is connected may result in internal and external conflicts, to feelings that one is not fully accepted by any of these groups, and ultimately to a lower level of psychological well-being. [ABSTRACT FROM AUTHOR]

This paper provides an introduction to the articles submitted to the special issue of Trends in Organized Crime bringing forward numerous empirical research findings and theoretical accounts on Chinese organized crime in China and beyond. [ABSTRACT FROM AUTHOR]

Recent events have shifted the way the Chinese state responds to organized crime and corruption. The re-definition of organized crime, improved judicial oversight and the re-assessment of 'strike-hard' style police campaigns are key reforms. This paper discusses the recent changes in law, practice and oversight in the context of a brief overview of criminal groups in China and the Chongqing policing model. Revisions to the criminal law are described and the likely outcomes are assessed in the context of the key struggle to contain corruption and organized crime. [ABSTRACT FROM AUTHOR]

In order to elucidate the cytological mechanism of 2 n pollen formation in Chinese jujube, a cultivar named 'Linglingzao' (2 n = 2 x = 24) which produces relative more 2 n pollens naturally was employed for microsporogenesis analysis. Chromosomes paired in 12 bivalents at diakinesis and the first meiotic division was normal, whereas, the second division was characterized by frequent abnormal spindle orientation (parallel and tripolar spindles). Perpendicular, tripolar, and parallel spindles at metaphase II accounted for 72.93, 17.22, and 9.85% respectively. Perpendicular and tripolar spindles led to tetrads and triads formation respectively. Two types of parallel spindles were observed and a significant association correlation ( r = 0.84, P < 0.05) between parallel spindle II (fused spindles) and dyads was found which meant only fused spindles can form dyads, while parallel spindle I with a long distance between two sets of chromosomes seemed to lead tetrad formation. At tetrad stage, the observed frequencies of tetrads, triads and dyads were 80.99, 16.40, and 2.61% respectively. By the rule that each tetrad can form four n pollens, each triad can form one 2 n pollen and two n pollens, each dyad can form two 2 n pollens, the frequency of 2 n pollen estimated was 5.71%. Based on the pollen diameter difference between n and 2 n pollens, frequency of 2 n pollen observed was 6.15%. No significant difference was observed between frequency of 2 n pollen estimated and that of observed. The results indicated that, tripolar spindles and fused spindles at metaphase II followed by more triads and few dyads formation at tetrad stage were responsible for the production of 2 n pollen in Chinese jujube. 2 n gametes observed correspond to first division restitution. Research on the cytological mechanism of unreduced pollen will provide a platform for unreduced pollen induction and polyploidy breeding in Chinese jujube. [ABSTRACT FROM AUTHOR]

The predictability of planetary or ultra-long scale waves is limited by the large growth of errors in these scales in almost all the medium range forecast models. Understanding the cause for the enormous build up of error is, therefore, a necessary task for improving the prediction of planetary waves. A diagnostic analysis of the systematic error energetics has been performed in the Global Forecast System model to investigate the reasons for poor predictability of the lower tropospheric ultra-long waves (wavenumber bands 1-4) in tropics using the analysis-forecast system of horizontal wind field at 850 hPa level during the boreal summer period. For this purpose, systematic error energy is computed in spatial as well as in wavenumber domain. Non-linear inter-scale transfer of error has been formulated and evaluated through energy exchanges among participating triads. The study reveals that the error is generated in the prognostic model initially with a small magnitude at the different locations around tropical convergence zone (TCZ) attributed to the inaccuracy in representing different physical processes like cumulus convection applied in the model. At subsequent evolution of forecasts, error increases and spreads along the TCZ due to its non-linear advection to the higher scales and eventually to the ultra-long scales attributed to the inherent dynamics of the model evaluated through the process of wave-wave exchange of error energy in terms of the triad interactions. The continuous generation and then, non-linear propagation of error up to the planetary scales in the course of prediction increase the uncertainty in ultra-long scales which actually inhibit to predict accurately the planetary scale waves in tropics during medium range forecasts. This work suggests caveats to the modeler's community in the predictability study of tropical ultra-long waves. [ABSTRACT FROM AUTHOR]

The philosophical significance of Dmitri Mendeleev's successful predictions of the properties of gallium and scandium vis a vis the acceptance of the Periodic Table 1874-1886 has been debated recently. This author presents evidence that De Boisbaudran and Cleve both respectively predicted the possible existence of gallium and scandium, but on the basis of the old TRIAD methodology. This suggests that these successful Mendeleev predictions were therefore not independent corroboration of the concept of the Periodic System. Instead the significantly independent predictive successes for Mendeleev's system were (a) the determination of the atomic weight of the known element uranium as 240 instead of the previously accepted 120 in 1874 and (b) the isolation of germanium by Winkler in 1886. [ABSTRACT FROM AUTHOR]

For the model of thermal turbulence in the Boussinesq approximation with heating from below a change in the structure of the nonlinear interaction of the harmonics of the velocity field with the appearance of rotation is examined. The parameters of convection with rotation are chosen in such a way to correspond to the typical regimes in the models of the planetary dynamo. For such regimes, the structure of the triadic mechanism of the kinetic energy transfer through the spectrum is investigated. [ABSTRACT FROM AUTHOR]

In genetic studies, the transmission/disequilibrium test (TDT) using case–parent triads has gained popularity attributable to its robustness to population admixture. Several extensions have been proposed to accommodate incomplete triads. Some strategies assume that parental genotypes are missing completely at random (MCAR) to insure an unbiased conclusion and some methods allow parental genotypes to be missing informatively, resulting in reduced power when the missing data pattern is indeed MCAR. However, these tests assumed that offspring genotypes were MCAR. Recently, Guo indicated that when offspring genotypes were missing informatively, an occurrence that can be considered as ascertainment bias, inflated type-I error and/or reduced power may occur using the TDT when incomplete triads are excluded. In an effort to avoid an erroneous conclusion, we propose a strategy called testing informative missingness (TIM) that compares conditional distributions of parental genotypes among complete triads and incomplete data with only one parent to examine the missing data pattern. Through computer simulations, TIM has decent power to detect informative missingness and is robust to population admixture. In addition, we illustrate TIM with an application to the Framingham Heart Study.European Journal of Human Genetics (2008) 16, 992–1001; doi:10.1038/ejhg.2008.38; published online 12 March 2008 [ABSTRACT FROM AUTHOR]

This article examines the effects of dyadic ties and interpersonal trust on referrals and investment decisions of venture capitalists in the Chinese and Russian contexts. The study uses the postulate of transitivity of social network theory as a conceptual framework. The findings reveal that referee-venture capitalist tie, referee-entrepreneur tie, and interpersonal trust between referee and venture capitalist have positive effects on referrals and investment decisions of venture capitalists. The institutional, social and cultural differences between China and Russia have minimal effects on referrals. Interpersonal trust has positive effects on investment decisions in Russia. [ABSTRACT FROM AUTHOR]

Genetic as well as clinical data suggest that catechol O-methyltransferase (COMT) is involved in multiple complex psychiatric conditions. Recent studies have described an association between the Val158Met COMT polymorphism and panic disorder. Other recent investigations provide evidence that there are other loci within or nearby the COMT gene that may contribute to the susceptibility to panic disorder. To further evaluate the influence of the Val158Met COMT polymorphism in panic disorder we genotyped this marker in the coding region of the COMT gene and two additional variants (rs737865 and rs165599) in the 5′ and the 3′ region, respectively, in two independent Canadian samples: 121 nuclear families, and 89 cases with matched controls. In the nuclear families, significant transmission disequilibrium for the valine allele was observed between the alleles of the Val158Met COMT polymorphism and panic disorder (p<0.01). A significant excess of the valine allele was found in analysis of the case–control sample (p<0.01). This effect was mainly derived from the subgroup of females. This finding, including the female effect, replicates earlier results in studies of the Val158Met polymorphism in panic disorder. No significant results were found for the other two markers. These results support the hypothesis that the valine allele of the Val158Met COMT polymorphism or a nearby locus is involved in the etiopathogenesis of panic disorder.Neuropsychopharmacology (2006) 31, 2237–2242. doi:10.1038/sj.npp.1301048; published online 8 March 2006 [ABSTRACT FROM AUTHOR]

The Method of Sorting is a widely-used research tool for quantifying human cognition. It allows informants to provide data that are generally analysed with multidimensional scaling. Here the method was extended to collect additional information. In combination with the Method of Triads, it was applied to 36 brands of cigarette, resulting in a three-dimensional `Cigarette space', where the dimensions correspond to the main criteria on which brands were compared. Previous research, including reports from within the tobacco industry, provides points of comparison. One dimension resulting from tapping into the informants' accumulated expertise was closely correlated with tar content and can be identified as `strength' – in effect, a Strength scale for cigarette brands, allowing the informal distinction between light and heavy smokers to be refined. Other dimensions correspond to other aspects of taste. In a validity test, the map proved to be congruent with the same informants' preferences. [ABSTRACT FROM AUTHOR]

Two triad systems were synthesized from deuteroporphyrin IX by tethering 1,4-naphthoquinone derivative and aromatic amino acids to its propionic groups using the method of mixed anhydrides. Physicochemical characteristics of the triads were studied, and the π-electron systems of their chromophores were shown to interact. [ABSTRACT FROM AUTHOR]

This paper outlines recent conceptual and methodological developments in the assessment of triadic and family group process during infancy and toddlerhood. Foundations of the emerging family group process are identified, and conditions specific to the assessment of the family during the early phases of family formation are summarized. Both microanalytic and global approaches to evaluating mother–father–child interactions are discussed. We highlight both similarities and differences in the strategies and methods employed by several different investigators who have been studying the group dynamics of families with infant and toddler children, and underscore several important family patterns and emerging themes that appear to be cutting across these different methods and measurement strategies. Preliminary evidence for the validity and clinical significance of family-level assessments is summarized, and directions currently being pursued by researchers engaged in studies of the family triad are outlined. We close by identifying several conceptual and clinical issues that remain to be addressed by subsequent work. [ABSTRACT FROM AUTHOR]

The results of studies on the synthesis of porphyrin-quinone compounds and investigation of their photochemical properties are summarized. Effects of various factors (the redox potential, the distance between donor and acceptor moieties, their spatial orientation, the free energy of the reaction, and solvents) on the photoinduced electron transfer in these model systems are discussed. The dyad and triad model systems have been compared. The possibility of using these systems for modeling the primary steps of photosynthesis is discussed. [ABSTRACT FROM AUTHOR]

Recent research into children's conceptual representation-much of it based on the so-called 'triads' task-has created a number of issues such as the age at which children become capable of representation at the superordinate level; the relative prominence of taxonomic, perceptual or thematic relations as the basis of representation; and the range of categories to which these different representations apply at different ages. In the study reported in this paper we presented children of three different ages with three types of triads designed to assess children's sensitivity to these different relations separately across ten common superordinate categories. The approach which allowed us to track preferences for perceptual, thematic and taxonomic relations simultaneously across the three age groups showed an increase in sensitivity to both thematic and taxonomic relations with age. We conclude by suggesting that these relations are part of a common representation based on patterns of covariation within (static taxonomic relations) and across (event relations) time. [ABSTRACT FROM AUTHOR]

A modified staining technique for transverse tubular and sarcoplasmic reticular systems was used to investigate their occurrence in different types of intrafusal muscle fibres in cat tail spindles. Intrafusal muscle fibres can be divided into three basic regions, namely, the periaxial space (A-region), intracapsular area (B-region) and the extracapsular area (C-region); the components of these systems were seen to vary in structure and distribution. The occurrence of these systems also varied among the different types of intrafusal muscle fibres, namely, the bag, bag and chain fibres. In bag fibres components were sparse in the A-region, increased slightly in the B-region, but were most developed in the C-region; triads were consistently located at the border between A- and I-bands. In bag fibres membrane components were noted in the A-region but were more abundant in the B-region where some tubular components showed transverse and longitudinal branches linked together in the form of a network; membrane systems diminished towards the C-region. The majority of triads were located within the A-bands. In chain fibres the membrane systems occurred more commonly in the A-region, while in the B- and C-regions, the transverse tubular system possessed numerous transverse and longitudinal branches forming irregularly distributed tubular networks. Some tubular branches were dilated, while other branches terminated as sacs among arrays of the sarcoplasmic reticular system in I-bands. Some transverse tubules bifurcated into two branches with numbers of dilated sarcoplasmic reticular cisternae lying on either side, or between, the branches. Triads sometimes occurred between A- and I-bands, but, generally, were situated well within A-bands. [ABSTRACT FROM AUTHOR]

Electron microscopical studies of the thalamic AV-AM nuclei substantiated the presence of two main types of neurons, i.e. principal (or relay) cells and Golgi type II interneurons. Characteristic synaptic islands are found in abundance in the AV-AM. Four different types of synaptic terminals have been identified in these islands: RL-boutons = large axonal terminals with round synaptic vesicles; RS-boutons = small axonal terminals with round synaptic vesicles; F-boutons = small axonal profiles containing flattened synaptic vesicles, and F-profiles interpreted as presynaptic dendrite appendages, bearing pleomorphic vesicles, both belonging to the Golgi type II interneurons. - The synaptic relations were studied in normal preparations and after lesions in the mamillary body, limbic cortex and hippocampus. The specific afferents (RL-boutons) - originating from the medial mamillary nucleus - are presynaptic to both relay cell dendrites and 'presynaptic' dendrite profiles of Golgi type II interneurons, which in turn are presynaptic to the same relay dendrites (synaptic triads). RS-boutons originate mainly from limbic cortex and hippocampus. [ABSTRACT FROM AUTHOR]

We demonstrate for the first time in this study that triadic vesicles derived from skeletal muscle display a voltage dependence of depolarization-induced calcium release similar to that found in intact muscle. We confirm previous studies by Dunn (1989) which demonstrated that changes in extravesicular potassium induced membrane potential changes in isolated transverse tubules with the voltage sensitive dye DiSC(3)-5. Depolarization-induced calcium release was studied in isolated triadic vesicles through similar changes in extravesicular [K] while clamping extravesicular Ca to submicromolar concentrations. The amplitude of fast phase of calcium release, identified as depolarizationinduced calcium release, varied with the percentage of transverse tubules in the preparation (determined through H-PN200-110 specific activity) and different levels of depolarization. Threshold activation of calcium release was obtained with a 40.5 mV potential change; maximal calcium release was obtained with a 75 to 81 mV potential change. Boltzmann fits to the normalized depolarization induced calcium release plotted against the membrane potential change yielded a voltage dependence (k = 4.5 mV per e-fold change) very similar to that found in intact muscle (k = 3-4 mV per e-fold change; Baylor, Chandler & Marshall 1978, 1983; Miledi et al., 1981). Substitution of methanesulfonate for propionate as the impermeant ion or addition of valinomycin in the depolarizing solutions had little effect on the voltage dependence of calcium release. [ABSTRACT FROM AUTHOR]

Depolarization-induced Ca release was studied in a mixture of triads and terminal cisternae isolated from rabbit skeletal muscle. The vesicles were actively loaded with known amounts of Ca in the absence of precipitating anions in a solution containing 100 m m K propionate buffer. Changes in extravesicular Ca were monitored with 10 μ m Fura-2 (membrane impermeant form). Ca release was initiated by diluting an aliquot of the loaded vesicles into a TEACl release solution designed to maintain a constant [K] · [Cl] product. Fast release, defined as the percentage of total Ca loaded which released in less than 10 sec, occurred when extravesicular free Ca was in the submicromolar range and was unaffected by 5 m m caffeine under depolarizing conditions, change in external pH to 6.5, and an increase in external Mg concentration from 0.1 to 0.2 m m. Thus, the Ca release measured in these studies is distinct from Ca-induced Ca release. The fast release more than doubled when a greater dilution (1 ∶ 20 versus 1 ∶ 10) of the loaded vesicles into the release solution, which would produce a larger depolarization, was used. The percentage of loaded Ca which released rapidly in a particular triad preparation was similar to the percentage of vesicles structurally coupled as visualized by electron microscopy. [ABSTRACT FROM AUTHOR]

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When members of an organization share communication codes, coordination across subunits is easier. But if groups interact separately, they will each develop a specialized code. This paper asks: Can organizations shape how people interact in order to create shared communication codes? What kinds of design interventions in communication structures and systems are useful? In laboratory experiments on triads composed of dyads that solve distributed coordination problems, we examine the effect of three factors: transparency of communication (versus privacy), role differentiation, and the subjects' social history. We find that these factors impact the harmonization of dyadic codes into triadic codes, shaping the likelihood that groups develop group-level codes, converge on a single group-level code, and compress the group-level code into a single word. Groups with transparent communication develop more effective codes, while acyclic triads composed of strangers are more likely to use multiple dyadic codes, which are less efficient than group-level codes. Groups of strangers put into acyclic configurations appear to have more difficulty establishing "ground rules"—that is, the "behavioral common ground" necessary to navigate acyclic structures. These coordination problems are transient—groups of different structures end up with the same average communication performance if given sufficient time. However, lasting differences in the code that is generated remain. [ABSTRACT FROM AUTHOR]