Distribution Of Dyads Research Articles

Close Kin Dyads Indicate Intergenerational Dispersal and Barriers.

AbstractThe movement of individuals through continuous space is typically constrained by dispersal ability and dispersal barriers. A range of approaches have been developed to investigate these. Kindisperse is a new approach that infers recent intergenerational dispersal (σ) from close kin dyads and appears particularly useful for investigating taxa that are difficult to observe individually. This study, focusing on the mosquito Aedes aegypti, shows how the same close kin data can also be used for barrier detection. We empirically demonstrate this new extension of the method using genome-wide sequence data from 266 Ae. aegypti. First, we use the spatial distribution of full-sib dyads collected within one generation to infer past movements of ovipositing female mosquitoes. These dyads indicated the relative barrier strengths of two roads and performed favorably against alternative genetic methods for detecting barriers. We then use Kindisperse to quantify recent intergenerational dispersal (-197.1 m generation-1/2) from the difference in variance between the sib and the first cousin spatial distributions and, from this, estimate effective population density (-4,864 km-2). Dispersal estimates showed general agreement with those from mark-release-recapture studies. Barriers, σ, ρ, and neighborhood size (331-526) can inform forthcoming releases of dengue-suppressing Wolbachia bacteria into this mosquito population.

Linking Genetic Kinship and Demographic Analyses to Characterize Dispersal: Methods and Application to Blanding's Turtle.

Characterizing how frequently, and at what life stages and spatial scales, dispersal occurs can be difficult, especially for species with cryptic juvenile periods and long reproductive life spans. Using a combination of mark-recapture information, microsatellite genetic data, and demographic simulations, we characterize natal and breeding dispersal patterns in the long-lived, slow-maturing, and endangered Blanding's turtle (Emydoidea blandingii), focusing on nesting females. We captured and genotyped 310 individual Blanding's turtles (including 220 nesting females) in a central Wisconsin population from 2010 to 2013, with additional information on movements among 3 focal nesting areas within this population available from carapace-marking conducted from 2001 to 2009. Mark-recapture analyses indicated that dispersal among the 3 focal nesting areas was infrequent (<0.03 annual probability). Dyads of females with inferred first-order relationships were more likely to be found within the same nesting area than split between areas, and the proportion of related dyads declined with increasing distance among nesting areas. The observed distribution of related dyads for nesting females was consistent with a probability of natal dispersal at first breeding between nearby nesting areas of approximately 0.1 based on demographic simulations. Our simulation-based estimates of infrequent female dispersal were corroborated by significant spatial genetic autocorrelation among nesting females at scales of <500 m. Nevertheless, a lack of spatial genetic autocorrelation among non-nesting turtles (males and females) suggested extensive local connectivity, possibly mediated by male movements or long-distance movements made by females between terrestrial nesting areas and aquatic habitats. We show here that coupling genetic and demographic information with simulations of individual-based population models can be an effective approach for untangling the contributions of natal and breeding dispersal to spatial ecology.

Dyad content is reduced in cardiac myocytes of mice with impaired calmodulin regulation of RyR2.

In cardiac muscle, calmodulin (CaM) regulates the activity of several membrane proteins involved in Ca(2+) homeostasis (CaV1.2; RyR2, SERCA2, PMCA). Three engineered amino acid substitutions in the CaM binding site of the cardiac ryanodine receptor (RyR2) in mice (Ryr2 (ADA/ADA) ) strongly affect cardiac function, with impaired CaM inhibition of RyR2, reduced SR Ca(2+) sequestration, and early cardiac hypertrophy and death (Yamaguchi et al., J Clin Invest 117:1344-1353, 2007). We have examined the ultrastructure and RyR2 immunolocalization in WT and Ryr2 (ADA/ADA) hearts at ~10 days after birth. The myocytes show only minor evidence of structural damage: some increase in intermyofibrillar space, with occasional areas of irregular SR disposition and an increase in frequency of smaller myofibrils, despite an increase of about 15 % in average myocyte cross sectional area. Z line streaming, a sign of myofibrillar stress, is limited and fairly rare. Immunolabeling with an anti-RyR2 antibody shows that RyR-positive foci located at the level of the Z lines are less frequent in mutant hearts. A dramatic decrease in the frequency and size of dyads, accompanied by a decrease in occupancy of the gap by RyR2, but without obvious alterations in location and general structure is a notable ultrastructural feature. The data suggest that the uneven distribution of dyads or calcium release sites within the cells resulting from an overall reduction in RyR2 content may contribute to the poor cardiac performance and early death of Ryr2 (ADA/ADA) mice. An unusual fragmentation of mitochondria, perhaps related to imbalances in free cytoplasmic calcium levels, accompanies these changes.

Abstract CN09-03: Capitalizing on the teachable moment of the cancer diagnosis to promote healthful lifestyle changes among women with breast cancer and their daughters: Preliminary findings of the DAMES Trial

Abstract CN09-03: Capitalizing on the teachable moment of the cancer diagnosis to promote healthful lifestyle changes among women with breast cancer and their daughters: Preliminary findings of the DAMES Trial

Characterization of poly(2-propenoyl chloride) by nuclear magnetic resonance spectroscopy

A device to obtain the nuclear magnetic resonance (NMR) spectra of poly(2-propenoyl chloride) (PPC) avoiding any contact with the room moisture is described. The 1H and 13C NMR spectra of PPC in THF-d8 solution are thus obtained. The distribution of meso and racemic dyads inferred from the integration of different 1H NMR signals is: (m)=0.45 and (r)=0.55.

Positional and compositional heterogeneity of partially modified poly(propyleneimine) dendrimers

The partial end group modification of dendrimers leads to two types of heterogeneity in the product's structure: compositional heterogeneity (distribution of degree of substitution) and positional heterogeneity (spatial distribution of the substituents over the dendrimer molecule). Poly(propyleneimine) dendrimers were partially modified by direct amidation at 150°C with stearic acid. The compositional distribution (analysed by HPLC and ES-MS) follows a random pattern, governed by a binomial distribution. The positional distribution can be expressed as the distribution of dyads AA (two unreacted end groups), AB (one unreacted. one reacted) and BB (both reacted), where a dyad consists of two end groups originating at a common final branching point in the dendrimer. 13 C NMR and a Cu(II) complexation titration were used for determining the dyad distribution. Lower generations of dendrimers give a random distribution of dyads. In higher generations a marked preference for single substitution of dyads was found, possibly caused by intramolecular interactions or steric hindrance.

Late-Life Sibling Relationships: Does Race Affect Typological Distribution?

Using a typology of sibling relationships in old age (Gold, 1989a), effects of race on distribution of relationships were studied. Differences between elderly white and black sibling pairs on several dimensions were also examined. Analyses of interview data suggest that race is systematically related to distribution, but that other demographic variables do not significantly affect the distribution of dyads among categories in the typology. Using log linear models, it was shown that the interaction between race, type, and dyadic gender composition was significant. Data also suggest that black dyads are represented more frequently in the positive categories, and white dyads are more likely to be categorized as "apathetic" or "hostile."

Quality of Infants' Attachments to Professional Caregivers: Relation to Infant-Parent Attachment and Day-Care Characteristics

75 infants (mean age 15 months) were observed 3 times in the Strange Situation with their professional caregivers, mothers, and fathers. Sensitivity of these attachment figures to the infant's signals during free play, as well as a number of day-care characteristics, were assessed. Attachment classification distribution of infant-caregiver dyads did not differ significantly from infant-mother or infant-father attachment classification distributions. The quality of infant-caregiver attachment was independent of both infant-mother and infant-father attachments. About 10% of the infants had 3 insecure attachments. Professional caregivers observed with more than 1 infant did not have similar types of attachment classifications to all infants with whom they were observed. Infants who were securely attached to their professional caregivers spent more hours per week in day-care, and came from a middle-class background. Their caregivers appeared to be younger and more sensitive during free play than caregivers with whom the infants developed an insecure relationship.

Sibling relationships in old age: a typology.

Sibling interactions in old age have received limited attention in social science literature. This article examines the different kinds of relationships which exist between siblings in old age and the ways in which each type meets or ignores the social and psychological needs of older people. Five types of sibling relationships emerged from data collected in open-ended, exploratory interviews with thirty men and thirty women over the age of sixty-five who had at least one living sibling. Each type reflects a discrete pattern of instrumental support, emotional support, and contact, as well as a different degree of closeness, envy, resentment, approval, and involvement with the sibling. The distribution of same-sex and cross-sex dyads among the types suggests gender differences in sibling interactions based on the gender composition of the sibling dyad rather than on the gender of the respondent.

The effect of sequence distribution on glass transition in the theory of the cooperative Behaviour of random copolymers

The description of the cooperative behaviour of polymers in the glass transition region according to ADAM and GIBBS (1965) has been extended to comprise the dependence of glass transition temperature, Tg, on the chemical composition of random copolymers if the distribution of dyads of comonomer units is included. The compositional dependence of Tg is expressed in terms of (i) differences between the isobaric heat capacities in the liquid and glassy states, and of (ii) the equilibrium T2 temperatures of the parent homopolymers and of the alternating copolymer. Validity of this theory was verified by comparison with data on styrene/methyl methacrylate and styrene/n-octyl methacrylate copolymers; the results indicate that the relations derived agree quantitatively with the experiment similarly to the equations suggested earlier by JOHNSTON (1976) and BARTON (1970). Moreover, these relations are based on a physically better justified approach to the glass transition phenomenon.

Studies on triploid Allium triquetrum

This work describes the relationship between the univalents seen at metaphase I and the distribution of dyads at anaphase I in the pollen mother cells of triploid Allium triquetrum. The orientation of the centromeres within the trivalents and bivalents at metaphase I towards the two poles of the pollen mother cells is random. The distribution of polar univalents towards the two poles at metaphase I is also random, as is the distribution of dyads at anaphase I in “low” univalent frequency collections. However, in a “high” univalent frequency collection, the distribution of dyads at anaphase I is non-random. There is an excess of cells with the most equal dyad distribution (13–14) and a paucity of cells with a 12–15 distribution. In low univalent frequency collections, the equatorial univalents are believed to remain in the equatorial region during anaphase I and are seen as laggards at late anaphase I. The remaining chromosomes move according to the metaphase I orientation of their centromeres to give a random distribution of dyads at anaphase I. In high univalent frequency collections it is argued that the non-random dyad distribution seen at anaphase I is the result of non-random movement of some of the equatorial univalents away from the equatorial region during anaphase I. The remaining equatorial univalents remain in the equatorial region and are seen as laggards at late anaphase I.

Electron Microscopic Analysis of the Inner Synaptic Layer in the River Lamprey(Lampetra fluviatilis)

Different types of synaptic contacts between bipolar, amacrine and ganglion cells were scored on random electron micrographs and on montages comprising the entire thickness of the inner synaptic layer. Currently accepted criteria were used when classifying the different cell processes. The percental distribution of dyads was estimated to 56 % amacrine-amacrine dyads, 34 % amacrine-ganglion dyads and 10 % ganglion-ganglion dyads. The ratio of amacrine conventional synapses to bipolar ribbon synapses was 6.8 : 1. The density per unit area of conventional synapses (0.035/μm2) and ribbon synapses (0.005/ μm2) was found markedly low as compared with other vertebrate species except the carp. The inner synaptic layer of the river lamprey is suggested to be of the intermediate type in which both simple and complex ganglion cell receptive fields may be expected.

Study on the Distribution of Dyads in Acrylonitrile-Methyl Acrylate Copolymers by Pyrolysis Gas Chromatography

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStudy on the Distribution of Dyads in Acrylonitrile-Methyl Acrylate Copolymers by Pyrolysis Gas ChromatographyYoshiyuki Yamamoto, Shin Tsuge, and Tsugio TakeuchiCite this: Macromolecules 1972, 5, 3, 325–327Publication Date (Print):May 1, 1972Publication History Published online1 May 2002Published inissue 1 May 1972https://doi.org/10.1021/ma60027a019RIGHTS & PERMISSIONSArticle Views56Altmetric-Citations5LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (313 KB) Get e-Alerts Get e-Alerts

High Resolution NMR Study of Vinyl Chloride-Ethylene Copolymers

Abstract The high resolution NMR spectra of vinyl chloride-ethylene copolymers obtained by trialkylboron catalyst have been analyzed. The copolymer composition could be determined from the resonance peak area, and the monomer reactivity ratios thus obtained were in good consistency with those determined from the results of elementary analysis. The fine structure of the copolymers have been elucidated in terms of the run number concept, and the distribution of dyads as well as the average sequence lengths of the monomer unit have been determined. It was found that the observed values fitted theoretical values, indicating that a terminal model holds in this copolymerization.