Understanding the oriented-attachment growth of nanocrystals from an energy point of view: a review
NASA Astrophysics Data System (ADS)
Lv, Weiqiang; He, Weidong; Wang, Xiaoning; Niu, Yinghua; Cao, Huanqi; Dickerson, James H.; Wang, Zhiguo
2014-02-01
Since Penn et al. first discovered the oriented attachment growth of crystals, the oriented attachment mechanism has now become a major research focus in the crystal field, and extensive efforts have been carried out over the past decade to systematically investigate the growth mechanism and the statistical kinetic models. However, most of the work mainly focuses on the experimental results on the oriented attachment growth. In contrast to the previous reviews, our review provides an overview of the recent theoretical advances in oriented attachment kinetics combined with experimental evidences. After a brief introduction to the van der Waals interaction and Coulombic interaction in a colloidal system, the correlation between the kinetic models of oriented attachment growth and the interactions is then our focus. The impact of in situ experimental observation techniques on the study of oriented attachment growth is examined with insightful examples. In addition, the advances in theoretical simulations mainly investigating the thermodynamic origin of these interactions at the atomic level are reviewed. This review seeks to understand the oriented attachment crystal growth from a kinetic point of view and provide a quantitative methodology to rationally design an oriented attachment system with pre-evaluated crystal growth parameters.
Oriented attachment by enantioselective facet recognition in millimeter-sized gypsum crystals.
Viedma, Cristóbal; Cuccia, Louis A; McTaggart, Alicia; Kahr, Bart; Martin, Alexander T; McBride, J Michael; Cintas, Pedro
2016-09-22
Crystal growth by oriented attachment involves the spontaneous self-assembly of adjoining crystals with common crystallographic orientations. Herein, we report the oriented attachment of gypsum crystals on agitation to form stereoselective mesoscale aggregates.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Xiao, Dongdong; Wu, Zhigang; Song, Miao
Understanding the growth mechanism of noble metal nanocrystals during solution synthesis is of significant importance for shape and property control. However, much remains unknown about the growth pathways of metal nanoparticles due to lack of direct observation. Using an in-situ transmission electron microscopy technique, we directly observed Ag nanocube and nanobar growth in aqueous solution through both classical monomer-by-monomer addition and non-classical particle attachment processes. During the particle attachment process, Ag nanocubes and nanobars formed via both oriented and non-oriented attachment. Our calculations, along with dynamics of the observed attachment, showed that van der Waals force overcame hydrodynamic and frictionmore » forces and drove the particles toward each other. During classical growth, an anisotropic growth was also revealed, and the resulting unsymmetrical shape constituted an intermediate state for Ag nanocube growth. We hypothesized that the temporary symmetry breaking resulted from different growth rates on {001} surfaces due to a local surface concentration variation caused by the imbalance between the consumption of Ag+ near the surface and the diffusion of Ag+ from bulk to surface.« less
Realignment of Nanocrystal Aggregates into Single Crystals as a Result of Inherent Surface Stress
DOE Office of Scientific and Technical Information (OSTI.GOV)
Liu, Zhaoming; Pan, Haihua; Zhu, Genxing
2016-07-19
Assembly of nanoparticles building blocks during single crystal growth is widely observed in both natural and synthetic environments. Although this form of non-classical crystallization is generally described by oriented attachment, random aggregation of building blocks leading to single crystal products is also observed, but the mechanism of crystallographic realignment is unknown. We herein reveal that random attachment during aggregation-based growth initially produces a non-oriented growth front. Subsequent evolution of the orientation is driven by the inherent surface stress applied by the disordered surface layer and results in single crystal formation via grain boundary migration. This mechanism is corroborated by measurementsmore » of orientation rate vs external stress, demonstrating a predictive relationship between the two. These findings advance our understanding of aggregation-based growth of natural minerals by nanocrystals, and suggest an approach to material synthesis that takes advantage of stress induced co-alignment.« less
Influence of lattice orientation on growth and structure of graphene on Cu(001)
Wofford, Joseph M.; Nie, Shu; Thürmer, Konrad; ...
2015-03-31
We have used low-energy electron microscopy (LEEM) and diffraction (LEED) to examine the significance of lattice orientation in graphene growth on Cu(0 0 1). Individual graphene domains undergo anisotropic growth on the Cu surface, and develop into lens shapes with their long axes roughly aligned with Cu <1 0 0> in-plane directions. Furthermore, the long axis of a lens-shaped domain is only rarely oriented along a C <1 1> direction, suggesting that carbon attachment at “zigzag” graphene island edges is unfavorable. A kink-mediated adatom attachment process is consistent with the behavior observed here and reported in the literature. Likewise, themore » details of the ridged moiré pattern formed by the superposition of the graphene lattice on the (0 0 1) Cu surface also evolve with the graphene lattice orientation, and are predicted well by a simple geometric model. Managing the kink-mediated growth mode of graphene on Cu(0 0 1) will be necessary for the continued improvement of this graphene synthesis technique.« less
A possible oriented attachment growth mechanism for silver nanowire formation
Murph, Simona E. Hunyadi; Murphy, Catherine J.; Leach, Austin; ...
2015-04-06
Electron microscopy studies suggest that silver nanowires prepared by an approach reported earlier by us (Caswell, K. K., Bender, C. M., Murphy, C. J. Nano Lett.,2003, 3, 667–669) form through a coarsening process via an oriented attachment mechanism. Initially, silver nucleation centers were produced by chemical reduction of silver ions in boiling water, with sodium citrate and sodium hydroxide as additives in solution. These nucleation centers, with a twinned crystallographic orientation, ultimately merge into fully grown silver nanowires. This is a completely different mechanism from the seed-mediated growth approach, which has also been used to produce silver nanowires. Furthermore, companionmore » molecular dynamics performed with the embedded atom method are in agreement with our experimental data.« less
A possible oriented attachment growth mechanism for silver nanowire formation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Murph, Simona E. Hunyadi; Murphy, Catherine J.; Leach, Austin
Electron microscopy studies suggest that silver nanowires prepared by an approach reported earlier by us (Caswell, K. K., Bender, C. M., Murphy, C. J. Nano Lett.,2003, 3, 667–669) form through a coarsening process via an oriented attachment mechanism. Initially, silver nucleation centers were produced by chemical reduction of silver ions in boiling water, with sodium citrate and sodium hydroxide as additives in solution. These nucleation centers, with a twinned crystallographic orientation, ultimately merge into fully grown silver nanowires. This is a completely different mechanism from the seed-mediated growth approach, which has also been used to produce silver nanowires. Furthermore, companionmore » molecular dynamics performed with the embedded atom method are in agreement with our experimental data.« less
NASA Astrophysics Data System (ADS)
Cao, Yali; Hu, Pengfei; Jia, Dianzeng
2013-01-01
Hydrothermal strategies were successfully used to control the phases and morphologies of CdS nanocrystals. In the absence of an external direction-controlling process, the hexagonal and cubic phase well-defined leaf- and flower-like CdS nanocrystals were controlled obtained via adjusting the reaction duration or the concentration of surfactant. Oriented attachment growth modes were suggested for the formation of CdS superstructures, which was clarified through the tracing of temporal evolution of CdS nanoparticles. The CdS superstructures were structured by primary building nanoparticles, and held excellent visible emission with a peak in the green regions. This strategy is very helpful for studying the phase and morphology controlled fabrication of sulfides nanocrystals.
Fretting Stresses in Single Crystal Superalloy Turbine Blade Attachments
NASA Technical Reports Server (NTRS)
Arakere, Nagaraj K.; Swanson, Gregory
2000-01-01
Single crystal nickel base superalloy turbine blades are being utilized in rocket engine turbopumps and turbine engines because of their superior creep, stress rupture, melt resistance and thermomechanical fatigue capabilities over polycrystalline alloys. Currently the most widely used single crystal nickel base turbine blade superalloys are PWA 1480/1493 and PWA 1484. These alloys play an important role in commercial, military and space propulsion systems. High Cycle Fatigue (HCF) induced failures in aircraft gas turbine and rocket engine turbopump blades is a pervasive problem. Blade attachment regions are prone to fretting fatigue failures. Single crystal nickel base superalloy turbine blades are especially prone to fretting damage because the subsurface shear stresses induced by fretting action at the attachment regions can result in crystallographic initiation and crack growth along octahedral planes. Furthermore, crystallographic crack growth on octahedral planes under fretting induced mixed mode loading can be an order of magnitude faster than under pure mode I loading. This paper presents contact stress evaluation in the attachment region for single crystal turbine blades used in the NASA alternate Advanced High Pressure Fuel Turbo Pump (HPFTP/AT) for the Space Shuttle Main Engine (SSME). Single crystal materials have highly orthotropic properties making the position of the crystal lattice relative to the part geometry a significant factor in the overall analysis. Blades and the attachment region are modeled using a large-scale 3D finite element (FE) model capable of accounting for contact friction, material orthotrophy, and variation in primary and secondary crystal orientation. Contact stress analysis in the blade attachment regions is presented as a function of coefficient of friction and primary and secondary crystal orientation, Stress results are used to discuss fretting fatigue failure analysis of SSME blades. Attachment stresses are seen to reach peak values at locations where fretting cracks have been observed. Fretting stresses at the attachment region are seen to vary significantly as a function of crystal orientation. Attempts to adapt techniques used for estimating fatigue life in the airfoil region, for life calculations in the attachment region, are presented. An effective model for predicting crystallographic crack initiation under mixed mode loading is required for life prediction under fretting action.
The evolvement of pits and dislocations on TiO{sub 2}-B nanowires via oriented attachment growth
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhao Bin; Chen Feng, E-mail: Fengchen@ecust.edu.c; Qu Wenwu
2009-08-15
TiO{sub 2}-B nanowires were synthesized by an ion exchanging-thermal treatment. The unique morphology of pits and dislocations interspersed on TiO{sub 2}-B nanowires were firstly characterized and studied by high-resolution transmission electron microscopy (HRTEM). Oriented attachment is suggested as an important growth mechanism in the evolvement of pits and dislocations on TiO{sub 2}-B nanowires. Lattice shears and fractures were originally formed during the ion exchanging process of the sodium titanate nanowires, which resulted in the formation of primary crystalline units and vacancies in the layered hydrogen titanate nanowires. Then the (110) lattice planes of TiO{sub 2}-B grown in [110] direction ismore » faster than the other lattice planes, which caused the exhibition of long dislocations on TiO{sub 2}-B nanowires. The enlargement of the vacancies, which was caused by the rearrangement of primary crystalline units, should be the reason of the formation of pits. Additionally, the transformation from TiO{sub 2}-B to anatase could be also elucidated by oriented attachment mechanism. - Graphical abstract: The unique morphology of pits and dislocations on TiO{sub 2}-B nanowires shown in high-resolution transmission electron microscopy (HRTEM) and a proposed evolvement mechanism of pits and dislocations on TiO{sub 2}-B nanowires.« less
Closed membrane shapes with attached BAR domains subject to external force of actin filaments.
Mesarec, Luka; Góźdź, Wojciech; Iglič, Veronika Kralj; Kralj, Samo; Iglič, Aleš
2016-05-01
Membrane deformations induced by attached BAR superfamily domains could trigger or facilitate the growth of plasma membrane protrusions. The BAR domain family consists of BAR, F-BAR and I-BAR domains, each enforcing a different local curvature when attached to the membrane surface. Our theoretical study mainly focuses on the role of I-BAR in the membrane tubular deformations generated or stabilised by actin filaments. The influence of the area density of membrane attached BAR domains and their intrinsic curvature on the closed membrane shapes (vesicles) was investigated numerically. We derived an analytical approximative expression for the critical relative area density of BARs at which the membrane tubular protrusions on vesicles are most prominent. We have shown that the BARs with a higher intrinsic curvature induce thinner and longer cylindrical protrusions. The average orientation of the membrane attached BARs is altered when the vesicle shape is subjected to external force of growing actin rod-like structure inside a vesicle. The average orientation angle of membrane attached BARs may indicate whether the actin filaments are just stabilising the protrusion or generating it by stretching the vesicle. Copyright © 2016 Elsevier B.V. All rights reserved.
Birnbaum, Gurit E; Reis, Harry T; Mikulincer, Mario; Gillath, Omri; Orpaz, Ayala
2006-11-01
The authors explored the contribution of individual differences in attachment orientations to the experience of sexual intercourse and its association with relationship quality. In Study 1, 500 participants completed self-report scales of attachment orientations and sexual experience. The findings indicated that whereas attachment anxiety was associated with an ambivalent construal of sexual experience, attachment avoidance was associated with more aversive sexual feelings and cognitions. In Study 2, 41 couples reported on their attachment orientations and provided daily diary measures of sexual experiences and relationship interactions for a period of 42 days. Results showed that attachment anxiety amplified the effects of positive and negative sexual experiences on relationship interactions. In contrast, attachment avoidance inhibited the positive relational effect of having sex and the detrimental relational effects of negative sexual interactions. The authors discuss the possibility that attachment orientations are associated with different sex-related strategies and goals within romantic relationships.
Cormary, Benoit; Li, Tao; Liakakos, Nikos; ...
2016-06-14
The molecular and ensemble dynamics for the growth of hierarchical supercrystals of cobalt nanorods have been studied by in situ tandem X-ray Absorption Spectroscopy – Small Angle X-ray Scattering (XAS - SAXS). The super-crystals were obtained by reducing a Co(II) precursor under H 2 in the presence of a long chain amine and a long chain carboxylic acid. Complementary time-dependent ex situ TEM studies were also performed. The experimental data provide critical insights into the nanorod growth mechanism, and unequivocal evidence for a concerted growth-organization process. Nanorod formation involves cobalt nucleation, a fast atom by atom anisotropic growth and amore » slower oriented attach-ment process that continues well after cobalt reduction is complete. As a result, smectic-like ordering of the nanorods appears very early in the process, as soon as nanoparticle elongation appears, and nanorod growth takes place inside organized super-lattices, which can be regarded as mesocrystals.« less
ERIC Educational Resources Information Center
Lopez, Frederick G.; Fons-Scheyd, Alia
2008-01-01
This study examined interrelationships among role balance perceptions, adult attachment orientations, and depression within an ethnically diverse, mixed-gender sample of college students. Adult attachment orientations--and particularly attachment avoidance--significantly interacted with students' role balance levels to predict their depression…
Huang, Nan; Sun, Chao; Zhu, Mingwei; Zhang, Bin; Gong, Jun; Jiang, Xin
2011-07-01
ZnO:Al thin films with Al incorporation of 0-20 at.% were deposited through the sol-gel technique. Such a film undergoes a significant microstructure development, from columnar to granular structures and then nanorod arrays with increasing Al content. The important role of Al incorporation level in the microstructure evolution was determined using scanning electron microscopy, x-ray photoelectron spectroscopy and transmission electron microscopy. At low Al level, the transition from columnar to granular grains can be attributed to the coarsening barrier resulting from the introduction of Al into the matrix. However, oriented structures of ZnO nanorod arrays are formed at a high Al level. TEM investigation reveals that a nanorod with smooth morphology at the top and rough morphology at the bottom has a single-crystalline wurtzite structure, which is the aggregation of nanoparticles of a few nanometers in size formed through the orientation attachment mechanism followed by epitaxial growth on the aggregated particles. Finally, the physical properties of the ZnO films with different degrees of Al concentration are discussed. Such detailed microstructure studies may aid the understanding of the doping effect process on the growth of a film, which is essential to altering its physical or chemical properties.
Raju, Muralikrishna; van Duin, Adri C T; Fichthorn, Kristen A
2014-01-01
Oriented attachment (OA) of nanocrystals is now widely recognized as a key process in the solution-phase growth of hierarchical nanostructures. However, the microscopic origins of OA remain unclear. We perform molecular dynamics simulations using a recently developed ReaxFF reactive force field to study the aggregation of various titanium dioxide (anatase) nanocrystals in vacuum and humid environments. In vacuum, the nanocrystals merge along their direction of approach, resulting in a polycrystalline material. By contrast, in the presence of water vapor the nanocrystals reorient themselves and aggregate via the OA mechanism to form a single or twinned crystal. They accomplish this by creating a dynamic network of hydrogen bonds between surface hydroxyls and surface oxygens of aggregating nanocrystals. We determine that OA is dominant on surfaces that have the greatest propensity to dissociate water. Our results are consistent with experiment, are likely to be general for aqueous oxide systems, and demonstrate the critical role of solvent in nanocrystal aggregation. This work opens up new possibilities for directing nanocrystal growth to fabricate nanomaterials with desired shapes and sizes.
Attachment patterns of Arabs and Jews in Israel--are we really so different?
Lavy, Shiri; Azaiza, Faisal; Mikulincer, Mario
2012-01-01
Attachment orientations reflect internal representations of self, others, and relationships. Studies revealed meaningful cultural differences in attachment orientations, but few included Arab samples. to fill this gap, we compared attachment orientations of Jews and Arabs in Israel using valid measures. Israeli participants (292 Arabs and 206 Jews) described their attachment figures and completed the Experiences in Close Relationships questionnaire which measures anxious and avoidant attachment orientations in Arabic and Hebrew, respectively. Israeli Arabs reported higher attachment anxiety than Israeli Jews, but no difference was found in avoidance. Both groups reported that attachment figures were similar in gender and relationship type, and included romantic partners, relatives and friends. Findings should be considered cautiously due to sampling limitations. the results complement previous cross-cultural findings and Arabs-Jews differences in relationship-related norms/values. Higher attachment-anxiety scores observed among Israeli Arabs may be considered culturally normative with implications for the development of culturally competent interventions.
[Play therapy for a child with separation anxiety disorder].
Wu, Y Y; Chiu, Y N; Soong, W T
1995-06-01
Separation anxiety disorder is characterized by severe and exceeding anxiety and fear when a child is facing separation with attachment objects. More over, it affected the child in language, emotional and social interest and development. These children usually brought to physician's attention due to refusal to go to school, social withdraw or multiple somatic complaints with attachment behavior wanted to be nearby or closed to the attachment objects. A child's early attachment relationship and previous separation experience play a major role in the formation of separation anxiety disorder. This report presents a psychoanalytically-oriented play therapy for a 2-year-8-month-old boy in 17 months period total of 54 sessions. According to the main themes in each session the process can be divided into 4 stages, namely establishing therapeutic relationship, expressing repressed emotions, management of transference, attachment and conflict in therapy, and self growth and termination. The formulation of this case and management were discussed.
Morphology design of porous coordination polymer crystals by coordination modulation.
Umemura, Ayako; Diring, Stéphane; Furukawa, Shuhei; Uehara, Hiromitsu; Tsuruoka, Takaaki; Kitagawa, Susumu
2011-10-05
The design of crystal morphology, or exposed crystal facets, has enabled the development (e.g., catalytic activities, material attributes, and oriented film formation) of porous coordination polymers (PCPs) without changing material compositions. However, because crystal growth mechanisms are not fully understood, control of crystal morphology still remains challenging. Herein, we report the morphology design of [Cu(3)(btc)(2)](n) (btc = benzene-1,3,5-tricarboxylate) by the coordination modulation method (modulator = n-dodecanoic acid or lauric acid). A morphological transition (octahedron-cuboctahedron-cube) in the [Cu(3)(btc)(2)](n) crystal was observed with an increase in concentration of the modulator. By suitably defining a coarse-grained standard unit of [Cu(3)(btc)(2)](n) as its cuboctahedron main pore and determining its attachment energy on crystal surfaces, Monte Carlo coarse-grain modeling revealed the population and orientation of carboxylates and elucidated an important role of the modulator in determining the <100>- and <111>-growth throughout the crystal growth process. This comprehension, in fact, successfully led to designed crystal morphologies with oriented growth on bare substrates. Because selective crystal orientations on the bare substrates were governed by crystal morphology, this contribution also casts a new light on the unexplored issue of the significance of morphology design of PCPs.
Linking Calling Orientations to Organizational Attachment via Organizational Instrumentality
ERIC Educational Resources Information Center
Cardador, M. Teresa; Dane, Erik; Pratt, Michael G.
2011-01-01
Despite an emerging interest in callings, researchers know little about whether calling orientations matter in the workplace. We explore the under-examined relationship between a calling orientation and employees' attachment to their organizations. Although some theory suggests that callings may be negatively related to organizational attachment,…
Attachment orientations as mediators in the intergenerational transmission of marital satisfaction.
Jarnecke, Amber M; South, Susan C
2013-08-01
Previous research suggests that there is an intergenerational transmission of marital satisfaction, such that parents' marital satisfaction predicts their adult child's marital satisfaction. The mechanisms that explain this phenomenon remain relatively unknown. In the current study, we examined the role of parent-child attachment orientations and romantic relationship attachment orientations as mediators in the intergenerational transmission of marital satisfaction. Participants (N = 199) were cohabiting newlywed couples who had been married for 12 months or less. All participants separately completed measures of own marital satisfaction, attachment orientations to romantic partners, attachment orientations to rearing parents, and perceptions of parents' marital satisfaction. Data was analyzed using the actor-partner interdependence model in a structural equation modeling framework to account for the nonindependent nature of the data. This allowed for examination of gender differences across husbands and wives and provided overall fit of the hypothesized model. Results supported a partially mediating effect of parent-child attachment and romantic partner attachment on the intergenerational transmission of marital satisfaction, although effects differed by gender. For husbands, the direct effect from parents' marital satisfaction to own satisfaction was partially mediated through anxious attachment styles. There was no direct effect from parents to own marital satisfaction for wives; however, there were significant links from parent's satisfaction to attachment orientations in childhood and adulthood, which in turn impacted wives satisfaction. Findings from this study provide an integrated look at the implications that attachment has on the intergenerational transmission of marital functioning. © 2013 American Psychological Association
Kohn, Jamie L; Rholes, Steven W; Simpson, Jeffry A; Martin, A McLeish; Tran, SiSi; Wilson, Carol L
2012-11-01
This longitudinal study investigated marital satisfaction trajectories across the first 2 years of parenthood. Data were collected from new parents (couples) 6 weeks before the birth of their first child, and then at 6, 12, 18, and 24 months postpartum. Growth curve models revealed two key findings. First, for highly anxious individuals, satisfaction was lower or declined when they perceived their partners as less supportive and as behaving more negatively toward them. Second, for highly avoidant individuals, satisfaction was lower or declined when they perceived more work-family conflict and greater demands from their families. The findings suggest that attachment insecurities predict dissatisfaction in new parents primarily when stressors block the pursuit of important attachment goals.
Homan, Kristin J
2018-03-01
Attachment style refers to a systematic pattern of emotions, behaviors, and expectations that people have for how others will respond in relationships. Extensive evidence has documented the importance of attachment security in infants, children, adolescents, and adults, but the effects of attachment among exclusively older adult populations have received less attention. The present study explored the relationships between attachment style in late adulthood and eudaimonic well-being, which refers to a life replete with meaning, productive activity, and striving to reach one's potential. It also explored the mediating role of self-compassion, which can be described as a kind and forgiving attitude toward the self. A sample of 126 community-dwelling older adults (mean age = 70.40 years) completed measures tapping adult attachment, self-compassion, and six theoretically derived markers of eudaimonic well-being. Attachment anxiety and avoidance were inversely related to self-acceptance, personal growth, interpersonal relationship quality, purpose in life, and environmental mastery. Mediation analyses showed that self-compassion mediated each of these relationships. Results support the importance of attachment orientation for psychological well-being in late life and indicate that secure attachment facilitates an attitude of kindness and acceptance toward the self.
Attachment, Social Value Orientation, Sensation Seeking, and Bullying in Early Adolescence
Innamorati, Marco; Parolin, Laura; Tagini, Angela; Santona, Alessandra; Bosco, Andrea; De Carli, Pietro; Palmisano, Giovanni L.; Pergola, Filippo; Sarracino, Diego
2018-01-01
In this study, bullying is examined in light of the “prosocial security hypothesis”— i.e., the hypothesis that insecure attachment, with temperamental dispositions such as sensation seeking, may foster individualistic, competitive value orientations and problem behaviors. A group of 375 Italian students (53% female; Mean age = 12.58, SD = 1.08) completed anonymous questionnaires regarding attachment security, social values, sensation seeking, and bullying behaviors. Path analysis showed that attachment to mother was negatively associated with bullying of others, both directly and through the mediating role of conservative socially oriented values, while attachment to father was directly associated with victimization. Sensation seeking predicted bullying of others and victimization both directly and through the mediating role of conservative socially oriented values. Adolescents’ gender affected how attachment moderated the relationship between sensation seeking and problem behavior. PMID:29535668
Attachment, Social Value Orientation, Sensation Seeking, and Bullying in Early Adolescence.
Innamorati, Marco; Parolin, Laura; Tagini, Angela; Santona, Alessandra; Bosco, Andrea; De Carli, Pietro; Palmisano, Giovanni L; Pergola, Filippo; Sarracino, Diego
2018-01-01
In this study, bullying is examined in light of the "prosocial security hypothesis"- i.e., the hypothesis that insecure attachment, with temperamental dispositions such as sensation seeking, may foster individualistic, competitive value orientations and problem behaviors. A group of 375 Italian students (53% female; Mean age = 12.58, SD = 1.08) completed anonymous questionnaires regarding attachment security, social values, sensation seeking, and bullying behaviors. Path analysis showed that attachment to mother was negatively associated with bullying of others, both directly and through the mediating role of conservative socially oriented values, while attachment to father was directly associated with victimization. Sensation seeking predicted bullying of others and victimization both directly and through the mediating role of conservative socially oriented values. Adolescents' gender affected how attachment moderated the relationship between sensation seeking and problem behavior.
Murdock, Kyle W; Fagundes, Christopher P
2017-04-01
Low childhood socioeconomic status (SES) is reliably associated with poor adult health. Social environments early in life and physiological stress responses are theorized to underlie this link; however, the role of attachment orientations is relatively unknown. In this study, we examined whether attachment orientations (i.e., attachment anxiety and attachment avoidance) and self-reported stress were mediators of the association between childhood SES and self-reported health in adulthood. Furthermore, we examined whether parasympathetic nervous system functioning was a moderator of associations between attachment orientations and self-reported stress. Participants (N = 213) provided self-reports of childhood SES, attachment orientations, general stress, and self-rated health. Respiratory sinus arrhythmia (RSA) was measured at rest, as well as during an acute social stressor. Low childhood SES was associated with poor self-reported health via the serial pathway from attachment anxiety to general stress. Moreover, attachment avoidance was associated with self-reported health via general stress, but only among those with high stress-induced RSA. Findings were independent of participant age, sex, race, body mass index, baseline RSA, and adult SES. Attachment theory is useful for understanding why those from low SES backgrounds are at greater risk of negative health outcomes in adulthood. Findings extend our knowledge of how interpersonal relationships in childhood can shape emotional and physical health outcomes in adulthood.
Murdock, Kyle W.; Fagundes, Christopher P.
2016-01-01
Background Low childhood SES is reliably associated with poor adult health. Social environments early in life and physiological stress responses are theorized to underlie this link; however, the role of attachment orientations is relatively unknown. Purpose In this study, we examined whether attachment orientations (i.e., attachment anxiety and attachment avoidance) and self-reported stress were mediators of the association between childhood SES and self-reported health in adulthood. Furthermore, we examined whether parasympathetic nervous system functioning was a moderator of associations between attachment orientations and self-reported stress. Methods Participants (N = 213) provided self-reports of childhood SES, attachment orientations, stress, and self-rated health. Respiratory sinus arrhythmia (RSA) was measured at rest, as well as during an acute social stressor. Results Low childhood SES was associated with poor self-reported health via the serial pathway from attachment anxiety to general stress. Moreover, attachment avoidance was associated with self-reported health via general stress, but only among those with high stress-induced RSA. Findings were independent of participant age, sex, race, body mass index, baseline RSA, and adult SES. Conclusions Attachment theory is useful for understanding why those from low SES backgrounds are at greater risk of negative health outcomes in adulthood. Findings extend our knowledge of how interpersonal relationships in childhood can shape emotional and physical health outcomes in adulthood. PMID:27679464
Peleg, Shira; Vilchinsky, Noa; Fisher, William A; Khaskia, Abed; Mosseri, Morris
2017-12-01
To achieve a comprehensive understanding of patients' adherence to medication following acute coronary syndrome (ACS), we assessed the possible moderating role played by attachment orientation on the effects of attitudes, subjective norms, and perceived behavioral control (PBC), as derived from the Theory of Planned Behavior (TPB; Ajzen, 1991), on intention and reported adherence. A prospective longitudinal design was employed. During hospitalization, ACS male patients (N = 106) completed a set of self-report questionnaires including sociodemographic variables, attachment orientation, and measures of TPB constructs. Six months post-discharge, 90 participants completed a questionnaire measuring adherence to medication. Attachment orientations moderated some of the predictions of the TPB model. PBC predicted intention and reported adherence, but these associations were found to be significant only among individuals with lower, as opposed to higher, attachment anxiety. The association between attitudes and intention was stronger among individuals with higher, as opposed to lower, attachment anxiety. Only among individuals with higher attachment avoidance, subjective norms were negatively associated with intention to take medication. Cognitive variables appear to explain both adherence intention and behavior, but differently, depending on individuals' attachment orientations. Integrating personality and cognitive models may prove effective in understanding patients' health behaviors. © 2016 Wiley Periodicals, Inc.
Ondry, Justin C; Hauwiller, Matthew R; Alivisatos, A Paul
2018-04-24
Using in situ high-resolution TEM, we study the structure and dynamics of well-defined edge dislocations in imperfectly attached PbTe nanocrystals. We identify that attachment of PbTe nanocrystals on both {100} and {110} facets gives rise to b = a/2⟨110⟩ edge dislocations. Based on the Burgers vector of individual dislocations, we can identify the glide plane of the dislocations. We observe that defects in particles attached on {100} facets have glide planes that quickly intersect the surface, and HRTEM movies show that the defects follow the glide plane to the surface. For {110} attached particles, the glide plane is collinear with the attachment direction, which does not provide an easy path for the dislocation to reach the surface. Indeed, HRTEM movies of dislocations for {110} attached particles show that defect removal is much slower. Further, we observe conversion from pure edge dislocations in imperfectly attached particles to dislocations with mixed edge and screw character, which has important implications for crystal growth. Finally, we observe that dislocations initially closer to the surface have a higher speed of removal, consistent with the strong dislocation free surface attractive force. Our results provide important design rules for defect-free attachment of preformed nanocrystals into epitaxial assemblies.
Growth kinetics of disk-shaped copper islands in electrochemical deposition.
Guo, Lian; Zhang, Shouliang; Searson, Peter
2009-05-01
The ability to independently dictate the shape and crystal orientation of islands in electrocrystallization remains a significant challenge. The main reason for this is that the complex interplay between the substrate, nucleation, and surface chemistry is not fully understood. Here we report on the kinetics of island growth for copper on ruthenium oxide. The small nucleation overpotential leads to enhanced lateral growth and the formation of hexagonal disk-shaped islands. The amorphous substrate allows the nuclei to achieve the thermodynamically favorable orientation, i.e., a 111 surface normal. Island growth follows power law kinetics in both lateral and vertical directions. At shorter times, the two growth exponents are equal to 1/2 whereas at longer times lateral growth slows down while vertical growth speeds up. We propose a growth mechanism, wherein the lateral growth of disk-shaped islands is initiated by attachment of Cu adatoms on the ruthenium oxide surface onto the island periphery while vertical growth is initiated by two-dimensional nucleation on the top terrace and followed by lateral step propagation. These results indicate three criteria for enhanced lateral growth in electrodeposition: (i) a substrate that leads to a small nucleation overpotential, (ii) fast adatom surface diffusion on substrate to promote lateral growth, and (iii) preferential anion adsorption to stabilize the basal plane.
Human Urine Decreases Function and Expression of Type 1 Pili in Uropathogenic Escherichia coli
Greene, Sarah E.; Hibbing, Michael E.; Janetka, James; Chen, Swaine L.
2015-01-01
ABSTRACT Uropathogenic Escherichia coli (UPEC) is the primary cause of community-acquired urinary tract infections (UTIs). UPEC bind the bladder using type 1 pili, encoded by the fim operon in nearly all E. coli. Assembled type 1 pili terminate in the FimH adhesin, which specifically binds to mannosylated glycoproteins on the bladder epithelium. Expression of type 1 pili is regulated in part by phase-variable inversion of the genomic element containing the fimS promoter, resulting in phase ON (expressing) and OFF (nonexpressing) orientations. Type 1 pili are essential for virulence in murine models of UTI; however, studies of urine samples from human UTI patients demonstrate variable expression of type 1 pili. We provide insight into this paradox by showing that human urine specifically inhibits both expression and function of type 1 pili. Growth in urine induces the fimS phase OFF orientation, preventing fim expression. Urine also contains inhibitors of FimH function, and this inhibition leads to a further bias in fimS orientation toward the phase OFF state. The dual effect of urine on fimS regulation and FimH binding presents a potential barrier to type 1 pilus-mediated colonization and invasion of the bladder epithelium. However, FimH-mediated attachment to human bladder cells during growth in urine reverses these effects such that fim expression remains ON and/or turns ON. Interestingly, FimH inhibitors called mannosides also induce the fimS phase OFF orientation. Thus, the transduction of FimH protein attachment or inhibition into epigenetic regulation of type 1 pilus expression has important implications for the development of therapeutics targeting FimH function. PMID:26126855
Powell, Elisabeth M; Frankel, Leslie A; Umemura, Tomo; Hazen, Nancy
2017-08-01
The present study examines the hypothesis that adult attachment orientation, specifically anxious attachment, is related to children's diminished ability to self-regulate their food intake, and that this relationship is mediated by parents' persuasive-controlling feeding practices. Two hundred and sixty five mothers and fathers of preschool children completed online questionnaires that included measures of Adult Attachment Orientation, Parental Persuasive-Controlling Feeding Practices, and Child Self-Regulation of Eating. Structural equation modeling revealed a significant relationship between parental anxious attachment and child self-regulatory abilities, which was fully mediated by parental persuasive-controlling feeding. Also as predicted, parents' avoidant attachment was found to be unrelated to persuasive-controlling feeding and child self-regulated eating. Findings suggest that parents with an anxious attachment orientation may be more likely than other parents to try to use persuasive techniques to control their children's food intake, which may impair children's ability to regulate their food intake, increasing their obesity risk. Implications for intervention are discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.
Fischer, Natalie; Theis, Désirée
2014-06-01
School motivation and attachment typically decline after the transition to middle school. According to the stage-environment fit approach, extracurricular activities are supposed to promote motivation. However, research has shown that the effects depend on the quality of the activities, which usually is measured by assessing students' individual perceptions. This article adds to previous studies in examining effects of school-based extracurricular participation on the development of individual motivation (learning goal orientation) and school attachment depending on the quality of the activities (i.e., amounts of challenge and social support) at the school level. We focused on the motivation development of 3,230 students at 98 schools who filled in questionnaires in Grades 5 (2005), 7 (2007), and 9 (2009). The quality of extracurricular activities was assessed on the basis of responses from 4,270 students in Grades 5, 7, and 9 at the same schools at the first measurement point (2005). Thus, individual development of the longitudinal sample was predicted by aggregated quality measures at the school level. Three-level hierarchical linear growth-curve models including school level, student level, and time were calculated. Cross-level interactions were analyzed to examine the influence of extracurricular participation on individual development as a function of school quality. Results show that the effects of extracurricular participation on the development of learning goal orientation are dependent on both features of school quality, whereas the development of school attachment in particular is influenced by activities offering social support. Thus, the effects of extracurricular activities are based not only on individual perceptions of activity features but also on school quality. PsycINFO Database Record (c) 2014 APA, all rights reserved.
Constitutive and life modeling of single crystal blade alloys for root attachment analysis
NASA Technical Reports Server (NTRS)
Meyer, T. G.; Mccarthy, G. J.; Favrow, L. H.; Anton, D. L.; Bak, Joe
1988-01-01
Work to develop fatigue life prediction and constitutive models for uncoated attachment regions of single crystal gas turbine blades is described. At temperatures relevant to attachment regions, deformation is dominated by slip on crystallographic planes. However, fatigue crack initiation and early crack growth are not always observed to be crystallographic. The influence of natural occurring microporosity will be investigated by testing both hot isostatically pressed and conventionally cast PWA 1480 single crystal specimens. Several differnt specimen configurations and orientations relative to the natural crystal axes are being tested to investigate the influence of notch acuity and the material's anisotropy. Global and slip system stresses in the notched regions were determined from three dimensional stress analyses and will be used to develop fatigue life prediction models consistent with the observed lives and crack characteristics.
Caregivers' burden and depressive symptoms: the moderational role of attachment orientations.
Vilchinsky, Noa; Dekel, Rachel; Revenson, Tracey A; Liberman, Gabriel; Mosseri, Morris
2015-03-01
The current study explored whether attachment orientations moderate the associations between caregiver burden and depressive symptoms among women coping with their partners' first time acute coronary syndrome. The association between burden and depression was hypothesized to be stronger among caregivers high on anxious attachment than among caregivers low on this dimension. In addition, the association between burden and depressive symptoms was hypothesized to be weaker among caregivers higher on avoidant attachment than among those lower on this dimension. The sample consisted of 111 female caregivers of male patients admitted to the cardiac care unit of a hospital in Israel. Caregivers completed a measure of attachment orientations during patients' hospitalization (baseline). Caregiver burden was measured 1 month later. Depressive symptoms were measured at baseline and again at 6-month follow-up. Structural equation modeling was used to test the moderational models. The association between caregiver burden and depressive symptoms at follow-up was moderated by attachment-related anxiety but not attachment-related avoidance. Congruent with predictions, a stronger association between caregiver burden and depressive symptoms occurred for caregivers with greater (vs. lower) attachment anxiety. The findings shed light on the possible dynamics among attachment orientations and affect regulation when coping with one's partner's illness. The findings are discussed in light of Pietromonaco, Uchino, and Dunkel Schetter's (2013) model of integrating attachment into health psychology research. PsycINFO Database Record (c) 2015 APA, all rights reserved.
Direction-specific interaction forces underlying zinc oxide crystal growth by oriented attachment
Zhang, X.; Shen, Z.; Liu, J.; ...
2017-10-10
Here, crystallization by particle attachment is impacting our understanding of natural mineralization processes and holds promise for novel materials design. When particles assemble in crystallographic registry, expulsion of the intervening solvent and particle coalescence is enabled by near-perfect co-alignment via interparticle forces that remain poorly quantified. Here we report measurement and simulation of these nanoscale aligning forces for the ZnO(0001)-ZnO(000¯1) system in aqueous solution. Dynamic force spectroscopy using nanoengineered single crystal probes reveals an attractive force with 60o rotational periodicity. Calculated distance and orientation-dependent potentials of mean force show several attractive free energy wells distinguished by numbers of intervening watermore » layers, which reach a minimum when aligned. The calculated activation energy to separate the attractively bound solvated interfaces perfectly reproduces the measured 60o periodicity, revealing the key role of intervening water structuring as a basis to generate the interparticle torque that completes alignment and enables coalescence.« less
Direction-specific interaction forces underlying zinc oxide crystal growth by oriented attachment
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhang, X.; Shen, Z.; Liu, J.
Here, crystallization by particle attachment is impacting our understanding of natural mineralization processes and holds promise for novel materials design. When particles assemble in crystallographic registry, expulsion of the intervening solvent and particle coalescence is enabled by near-perfect co-alignment via interparticle forces that remain poorly quantified. Here we report measurement and simulation of these nanoscale aligning forces for the ZnO(0001)-ZnO(000¯1) system in aqueous solution. Dynamic force spectroscopy using nanoengineered single crystal probes reveals an attractive force with 60o rotational periodicity. Calculated distance and orientation-dependent potentials of mean force show several attractive free energy wells distinguished by numbers of intervening watermore » layers, which reach a minimum when aligned. The calculated activation energy to separate the attractively bound solvated interfaces perfectly reproduces the measured 60o periodicity, revealing the key role of intervening water structuring as a basis to generate the interparticle torque that completes alignment and enables coalescence.« less
Moving template analysis of crack growth. 1: Procedure development
NASA Astrophysics Data System (ADS)
Padovan, Joe; Guo, Y. H.
1994-06-01
Based on a moving template procedure, this two part series will develop a method to follow the crack tip physics in a self-adaptive manner which provides a uniformly accurate prediction of crack growth. For multiple crack environments, this is achieved by attaching a moving template to each crack tip. The templates are each individually oriented to follow the associated growth orientation and rate. In this part, the essentials of the procedure are derived for application to fatigue crack environments. Overall the scheme derived possesses several hierarchical levels, i.e. the global model, the interpolatively tied moving template, and a multilevel element death option to simulate the crack wake. To speed up computation, the hierarchical polytree scheme is used to reorganize the global stiffness inversion process. In addition to developing the various features of the scheme, the accuracy of predictions for various crack lengths is also benchmarked. Part 2 extends the scheme to multiple crack problems. Extensive benchmarking is also presented to verify the scheme.
Sleep architecture and sleep-related mentation in securely and insecurely attached people
McNamara, Patrick; Pace-Schott, Edward F.; Johnson, Patricia; Harris, Erica; Auerbach, Sanford
2011-01-01
Based on REM sleep’s brain activation patterns and its participation in consolidation of emotional memories, we tested the hypothesis that measures of REM sleep architecture and REM sleep-related mentation would be associated with attachment orientation. After a habituation night in a sleep lab, a convenience sample of 64 healthy volunteers were awakened 10 minutes into a REM sleep episode and 10 minutes into a control NREM sleep episode in counterbalanced order, then asked to report a dream and to rate themselves and a significant other on a list of trait adjectives. Relative to participants classified as having secure attachment orientations, participants classified as anxious took less time to enter REM sleep and had a higher frequency of REM dreams with aggression and self-denigrating themes. There were no significant differences across attachment groups in other measures of sleep architecture or in post REM-sleep awakening ratings on PANAS subscales reflecting mood and alertness. Selected aspects of REM sleep architecture and mentation appeared to be associated with attachment orientation. We suggest that REM sleep plays a role in processing experiences and emotions related to attachment, and that certain features of sleep and dreaming reflect attachment orientations. PMID:21390907
Koning, G A; Morselt, H W; Gorter, A; Allen, T M; Zalipsky, S; Kamps, J A; Scherphof, G L
2001-09-01
Compare pharmacokinetics of tumor-directed immunoliposomes in healthy and tumor-bearing rats (hepatic colon cancer metastases). A tumor cell-specific monoclonal antibody was attached to polyethyleneglycol-stabilized liposomes, either in a random orientation via a lipid anchor (MPB-PEG-liposomes) or uniformly oriented at the distal end of the PEG chains (Hz-PEG-liposomes). Pharmacokinetics and tissue distribution were determined using [3H]cholesteryloleylether or bilayer-anchored 5-fluoro[3H]deoxyuridine-dipalmitate ([3H]FUdR-dP) as a marker. In healthy animals clearance of PEG-(immuno)liposomes was almost log-linear and only slightly affected by antibody attachment; in tumor-bearing animals all liposomes displayed biphasic clearance. In normal and tumor animals blood elimination increased with increasing antibody density; particularly for the Hz-PEG-liposomes, and was accompanied by increased hepatic uptake, probably due to increased numbers of macrophages induced by tumor growth. The presence of antibodies on the liposomes enhanced tumor accumulation: uptake per gram tumor tissue (2-4% of dose) was similar to that of liver. Remarkably, this applied to tumor-specific and irrelevant antibody. Increased immunoliposome uptake by trypsin-treated Kupffer cells implicated involvement of high-affinity Fc-receptors on activated macrophages. Tumor growth and immunoliposome characteristics (antibody density and orientation) determine immunoliposome pharmacokinetics. Although with a long-circulating immunoliposome formulation, efficiently retaining the prodrug FUdR-dP, we achieved enhanced uptake by hepatic metastases, this was probably not mediated by specific interaction with the tumor cells, but rather by tumor-associated macrophages.
Surface growth kinematics via local curve evolution.
Moulton, Derek E; Goriely, Alain
2014-01-01
A mathematical framework is developed to model the kinematics of surface growth for objects that can be generated by evolving a curve in space, such as seashells and horns. Growth is dictated by a growth velocity vector field defined at every point on a generating curve. A local orthonormal basis is attached to each point of the generating curve and the velocity field is given in terms of the local coordinate directions, leading to a fully local and elegant mathematical structure. Several examples of increasing complexity are provided, and we demonstrate how biologically relevant structures such as logarithmic shells and horns emerge as analytical solutions of the kinematics equations with a small number of parameters that can be linked to the underlying growth process. Direct access to cell tracks and local orientation enables for connections to be made to the underlying growth process.
NASA Astrophysics Data System (ADS)
Roy, Sukumar; Ghosh, Subrata; Bhowmick, Niranjan
2018-06-01
A mechanism to remove the Pseudomonas bacteria from contaminated water by using textile fibrous media has been proposed in this article. The attachment of Pseudomonas bacteria on nylon fibrous media was studied in laboratory column experiment. A systematic study was carried out to investigate the attachment of bacteria on the fibrous material as a function of fiber orientation to the direction of the liquid flow. Three types of textiles media with different orientation fiber were selected for the experiment (i.e. 0°, 45° and 90°). It was found that the bacteria removal efficiency was comparatively higher at 90° orientation as compared to that of 45° and 0° orientation of fibrous media, suggesting that the removal efficiency of bacteria (1 - Fp) was depended on fiber orientation. The removal trends were explained on the basis of colloidal filtration theory. This is due to the higher single collector contact efficiency and attachment/collision efficiency as observed from the experimental data of removal efficiency.
NASA Astrophysics Data System (ADS)
Roy, Sukumar; Ghosh, Subrata; Bhowmick, Niranjan
2018-05-01
A mechanism to remove the Pseudomonas bacteria from contaminated water by using textile fibrous media has been proposed in this article. The attachment of Pseudomonas bacteria on nylon fibrous media was studied in laboratory column experiment. A systematic study was carried out to investigate the attachment of bacteria on the fibrous material as a function of fiber orientation to the direction of the liquid flow. Three types of textiles media with different orientation fiber were selected for the experiment (i.e. 0°, 45° and 90°). It was found that the bacteria removal efficiency was comparatively higher at 90° orientation as compared to that of 45° and 0° orientation of fibrous media, suggesting that the removal efficiency of bacteria (1 - Fp) was depended on fiber orientation. The removal trends were explained on the basis of colloidal filtration theory. This is due to the higher single collector contact efficiency and attachment/collision efficiency as observed from the experimental data of removal efficiency.
Atomistic Insights Into the Oriented Attachment of Tunnel-Based Oxide Nanostructures
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yuan, Yifei; Wood, Stephen M; He, Kun
Controlled synthesis of nanomaterials is one of the grand challenges facing materials scientists. In particular, how tunnel-based nanomaterials aggregate during synthesis while maintaining their well-aligned tunneled structure is not fully understood. Here, we describe the atomistic mechanism of oriented attachment (OA) during solution synthesis of tunneled α-MnO2 nanowires based on a combination of in situ liquid cell transmission electron microscopy (TEM), aberration-corrected scanning TEM with subangstrom spatial resolution, and first-principles calculations. It is found that primary tunnels (1 × 1 and 2 × 2) attach along their common {110} lateral surfaces to form interfaces corresponding to 2 × 3 tunnelsmore » that facilitate their short-range ordering. The OA growth of α-MnO2 nanowires is driven by the stability gained from elimination of {110} surfaces and saturation of Mn atoms at {110}-edges. During this process, extra [MnOx] radicals in solution link the two adjacent {110} surfaces and bond with the unsaturated Mn atoms from both surface edges to produce stable nanowire interfaces. Our results provide insights into the controlled synthesis and design of nanomaterials in which tunneled structures can be tailored for use in catalysis, ion exchange, and energy storage applications.« less
Jeong, Jiyun; Lee, Yeolin; Yoo, Yeongeun; Lee, Myung Kyu
2018-02-01
Agarose gel can be used for three dimensional (3D) cell culture because it prevents cell attachment. The dried agarose film coated on a culture plate also protected cell attachment and allowed 3D growth of cancer cells. We developed an efficient method for agarose film coating on an oxygen-plasma treated micropost polystyrene chip prepared by an injection molding process. The agarose film was modified to maleimide or Ni-NTA groups for covalent or cleavable attachment of photoactivatable Fc-specific antibody binding proteins (PFcBPs) via their N-terminal cysteine residues or 6xHis tag, respectively. The antibodies photocrosslinked onto the PFcBP-modified chips specifically captured the target cells without nonspecific binding, and the captured cells grew 3D modes on the chips. The captured cells on the cleavable antibody-modified chips were easily recovered by treatment of commercial trypsin-EDTA solution. Under fluidic conditions using an antibody-modified micropost chip, the cells were mainly captured on the micropost walls of the chip rather than on the bottom of it. The presented method will also be applicable for immobilization of oriented antibodies on various microfluidic chips with different structures. Copyright © 2017 Elsevier B.V. All rights reserved.
ERIC Educational Resources Information Center
Mohr, Jonathan J.; Fassinger, Ruth E.
2003-01-01
A model linking attachment variables with self-acceptance and self-disclosure of sexual orientation was tested using data from 489 lesbian, gay, and bisexual (LGB) adults. The model included the following 4 domains of variables: (a) representations of childhood attachment experiences with parents, (b) perceptions of parental support for sexual…
Attachment at work and performance.
Neustadt, Elizabeth A; Chamorro-Premuzic, Tomas; Furnham, Adrian
2011-09-01
This paper examines the relations between self-reported attachment orientation at work and personality, self-esteem, trait emotional intelligence (aka emotional self-efficacy), and independently assessed career potential and job performance. Self-report data were collected from 211 managers in an international business in the hospitality industry; independent assessments of these managers' job performance and career potential were separately obtained from the organization. A self-report measure of romantic attachment was adapted for application in the work context; a two-factor solution was found for this measure. Secure/autonomous attachment orientation at work was positively related to self-esteem, trait emotional intelligence, extraversion, agreeableness, and conscientiousness, and also to job performance. Not only was secure/autonomous attachment orientation at work statistically predictive of job performance, but the new measure also made a distinct contribution, beyond conscientiousness, to this prediction.
An atomistic mechanism study of GaN step-flow growth in vicinal m-plane orientations
Liu, Zhun; Wang, Ru-Zhi; Zapol, Peter
2016-10-12
We present elucidation of homoepitaxial growth mechanisms on vicinal non-polar surfaces of GaN that is highly important for gaining an understanding of and control thin film surface morphology and properties. Using first-principles calculations, we study the step-flow growth in m-plane GaN based on atomic row nucleation and kink propagation kinetics. Ga–N dimer adsorption onto the m-plane is energetically more favorable than that of Ga and N isolated adatoms. Therefore, we have treated the dimers as the dominant growth species attached to the step edges. By calculating the free energies of sequentially attached Ga–N dimers, we have elucidated that the a-stepmore » edge kink growth proceeds by parallel attachment rather than by across the step edge approach. We found a series of favorable configurations of kink propagation and calculated the free energy and nucleation barriers for kink evolution on five types of step edges (a, +c, -c, +a + c, and -a - c). By changing the chemical potential μGa and the excess chemical potential Δμ, the growth velocities at the five types of edges are controlled by the corresponding kink pair nucleation barrier E* in their free energy profiles. To explore the kink-flow growth instability observed at different Ga/N flux ratios, calculations of kink pairs on the incompact -c and +c-step edges are further performed to study their formation energies. Variations of these step edge morphologies with a tuned chemical environment are consistent with previous experimental observations, including stable diagonal ±a ± c-direction steps. In conclusion, our work provides a first-principles approach to explore step growth and surface morphology of the vicinal m-plane GaN, which is applicable to analyze and control the step-flow growth of other binary thin films.« less
Guo, Xiamei
2018-01-01
The crude divorce rate has been increasing steadily for over a decade in China. Consequently, more and more children have to face the challenge of growing up in single parent families. The current study investigated the mediating effects of problem-oriented and emotion-oriented coping on the relationship between parental attachment and psychological resilience among a sample of Chinese adolescents from single parent families and intact families. Participants were 975 high school students (44.30% males; aged 15-19 years, M = 16.32 years, SD = 0.74), 871 from intact families and 104 from single parent families. Structural equation modeling showed that security in maternal attachment was positively associated with resilience through the indirect effect of reduced emotion-oriented coping among adolescents from single parent families. Among adolescents from intact families, security in maternal attachment was both directly associated with resilience and indirectly through enhanced problem-oriented and reduced emotion-oriented coping. Security in paternal attachment was associated with resilience both directly and indirectly through enhanced problem-oriented coping as well among those from intact families. Female adolescents exhibited significantly lower levels of resilience than male adolescents did regardless of the marital status of their parents. Limitations and suggestions for future research are discussed.
Zirconium diselenite microstructures, formation and mechanism
NASA Astrophysics Data System (ADS)
Naik, Chandan C.; Salker, A. V.
2018-04-01
In this work, a series of microstructures of zirconium diselenite (Zr(SeO3)2) has been prepared via a simple precipitation method at room temperature without adding any organic surfactants. Phase purity of the sample has been checked by X-ray Diffraction. From the SEM, FESEM, and TEM images spheroid nanoparticles to the starfish-like structure of zirconium diselenite are detected. The morphological evolution processes were investigated carefully following time-dependent experiments and a growth mechanism has been proposed. Two different crystal growth processes, the oriented attachment process accompanying the Ostwald ripening process were held responsible for the formation of a structure resembling starfish having four arms.
Yaakobi, Erez; Williams, Kipling D
2016-03-01
Ostracism--being excluded and ignored--is painful and threatens needs for belonging, self-esteem, control and meaningful existence. Many studies have shown that immediate responses to ostracism tend to be resistant to moderation. Once ostracized individuals are able to reflect on the experience, however, personality and situational factors moderate recovery speed and behavioural responses. Because attachment orientation is grounded in perceptions of belonging, we hypothesized that attachment orientation would moderate both immediate and delayed reactions to laboratory-induced ostracism. Participants from individualistic or collectivistic cultures were either included or ostracized in a game of Cyberball, a virtual ball-toss game. In both cultures, we found that compared to more securely attached individuals, more avoidant participants were less distressed by ostracism, but more distressed by inclusion. It is suggested that over and beyond differences in culture, individuals who avoid meaningful attachment may be less affected by ostracism. © 2015 The British Psychological Society.
Van Sluytman, Laurens; Spikes, Pilgrim; Nandi, Vijay; Van Tieu, Hong; Frye, Victoria; Patterson, Jocelyn; Koblin, Beryl
2015-01-01
In the USA, the impact of psychological distress may be greater for Black men who have sex with men given that they may experience both racial discrimination in society at large and discrimination due to sexual orientation within Black communities. Attachments to community members may play a role in addressing psychological distress for members of this vulnerable population. This analysis is based on 312 Black men who have sex with men recruited for a behavioural intervention trial in New York City. Analyses were conducted using bivariate and multivariable logistic regression to examine the relationship of discrimination and community attachment to psychological distress. Most participants (63%) reported exposure to both discrimination due to race and sexual orientation. However, a majority of participants (89%) also reported racial and/or sexual orientation community attachment. Psychological distress was significant and negatively associated with older age (40 years and above), being a high school graduate and having racial and/or sexual orientation community attachments. Psychological distress was significantly and positively associated with being HIV-positive and experiencing both racial and sexual orientation discrimination. Similar results were found in the multivariable model. Susceptibility to disparate psychological distress outcomes must be understood in relation to social membership, including its particular norms, structures and ecological milieu. PMID:25647586
Van Sluytman, Laurens; Spikes, Pilgrim; Nandi, Vijay; Van Tieu, Hong; Frye, Victoria; Patterson, Jocelyn; Koblin, Beryl
2015-01-01
In the USA, the impact of psychological distress may be greater for Black men who have sex with men given that they may experience both racial discrimination in society at large and discrimination due to sexual orientation within Black communities. Attachments to community members may play a role in addressing psychological distress for members of this vulnerable population. This analysis is based on 312 Black men who have sex with men recruited for a behavioural intervention trial in New York City. Analyses were conducted using bivariate and multivariable logistic regression to examine the relationship of discrimination and community attachment to psychological distress. Most participants (63%) reported exposure to both discrimination due to race and sexual orientation. However, a majority of participants (89%) also reported racial and/or sexual orientation community attachment. Psychological distress was significant and negatively associated with older age (40 years and above), being a high school graduate and having racial and/or sexual orientation community attachments. Psychological distress was significantly and positively associated with being HIV-positive and experiencing both racial and sexual orientation discrimination. Similar results were found in the multivariable model. Susceptibility to disparate psychological distress outcomes must be understood in relation to social membership, including its particular norms, structures and ecological milieu.
The role of attachment styles in regulating the effects of dopamine on the behavior of salespersons
Verbeke, Willem; Bagozzi, Richard P.; van den Berg, Wouter E.
2014-01-01
Two classic strategic orientations have been found to pervade the behavior of modern salespersons: a sales orientation (SO) where salespersons use deception or guile to get customers to buy even if they do not need a product, and a customer orientation (CO) where salespersons first attempt to discover the customer's needs and adjust their product and selling approach to meet those needs. Study 1 replicates recent research and finds that the Taq A1 variant of the DRD2 gene is not related to either sales or CO, whereas the 7-repeat variant of the DRD4 gene is related to CO but not SO. Study 2 investigates gene × phenotype explanations of orientation of salespersons, drawing upon recent research in molecular genetics and biological/psychological attachment theory. The findings show that attachment style regulates the effects of DRD2 on CO, such that greater avoidant attachment styles lead to higher CO for persons with the A2/A2 variant but neither the A1/A2 nor A1/A1 variants. Likewise, attachment style regulates the effects of DRD4 on CO, such that greater avoidant attachment styles lead to higher CO for persons with the 7-repeat variant but not other variants. No effects were found on a SO, and secure and anxious attachment styles did not function as moderators. PMID:24550811
García-Ruiz, Marta; Rodrigo, María José; Hernández-Cabrera, Juan A; Máiquez, María Luisa
2013-12-01
This study examined the contribution to parent-adolescent conflict resolution of parental adult attachment styles and attitudes toward adolescent separation. Questionnaires were completed by 295 couples with early to late adolescent children. Structural equation models were used to test self and partner influences on conflict resolution for three attachment orientations: confidence (model A), anxiety (model B) and avoidance (model C). Model A showed self influences between parents' confidence orientation and negotiation and also via positive attitudes towards separation. Also, the fathers' use of negotiation was facilitated by the mothers' confidence orientation and vice versa, indicating partner influences as well. Model B showed self influences between parents' anxiety orientation and the use of dominance and withdrawal and also via negative attitudes towards separation. Model C showed self influences between parents' avoidance orientation and dominance and withdrawal, and a partner influence between fathers' avoidance and mothers' use of dominance. The results indicated that the parents' adult attachment system and the parenting system were related in the area of conflict resolution, and that self influences were stronger than partner influences. © 2013 The Scandinavian Psychological Associations.
Kim, Sang Woo; Ahn, Jae-Pyoung
2013-01-01
This study proposes a seed/template-free method that affords high-purity semiconducting nanowires from nanoclusters, which act as basic building blocks for nanomaterials, under supercritical CO2 fluid. Polycrystalline nanowires of Gd-doped ceria (Gd-CeO2) were formed by CO2-mediated non-oriented attachment of the nanoclusters resulting from the dissociation of single-crystalline aggregates. The unique formation mechanism underlying this morphological transition may be exploited for the facile growth of high-purity polycrystalline nanowires. PMID:23572061
Structure evolution of self-catalyzed grown Au, Ag and their alloy nanostructure
NASA Astrophysics Data System (ADS)
Zhu, Zhu; Chen, Feng; Xu, Chunxiang; Yang, Guangcan; Zhu, Ye; Luo, Zhaoxu
2017-12-01
Monitoring the nucleation and growth of nanomaterials is a key technique for material synthesis design and control. An efficient fabrication method can be realized deeply understanding the growth mechanisms. Here, noble metal nanostructures, gold (Au) nanoparticles, silver nanostructures (Ag nanoparticles/Ag nanowires) and gold-silver alloy nanoparticles were prepared in a facile method at room temperature. The growth processes of the Au nanoparticles, Ag nanowires and Au-Ag alloy nanoparticles can be monitored real-timely through the ultraviolet visible absorption (UV-vis), dynamic light scattering (DLS) and transmission electron microscopy (TEM). It is found that the whole formation involved Digestive ripening and Ostwald ripening cooperative mechanism. Furthermore, the self-assembly growth is noticed in the oriented attachment of precursor Ag monomers into nanowires under the same synthetic conditions without external templates or rigorous conditions. This result can provide a platform to discover the underlying growth mechanism of wet-chemistry methods for metal nanostructure fabrication.
Ferenczi, Nelli; Marshall, Tara C
2016-02-01
Do insecurely attached individuals perceive greater rejection from their heritage culture? Few studies have examined the antecedents and outcomes of this perceived rejection - termed intragroup marginalization - in spite of its implications for the adjustment of cultural migrants to the mainstream culture. This study investigated whether anxious and avoidant attachment orientations among cultural migrants were associated with greater intragroup marginalization and, in turn, with lower subjective well-being and flourishing and higher acculturative stress. Anxious attachment was associated with heightened intragroup marginalization from friends and, in turn, with increased acculturative stress; anxious attachment was also associated with increased intragroup marginalization from family. Avoidant attachment was linked with increased intragroup marginalization from family and, in turn, with decreased subjective well-being.
Secretary of Defense's Spring 2018 Foreign Attachés Operations Orientation Program (OOP ). Thirty-five foreign attachés received an orientation brief and an introduction to JIATF South operations. OOP fosters closer cooperation between the U.S. Department of Defense and foreign militaries
The interrelationship between orthorexia nervosa, perfectionism, body image and attachment style.
Barnes, Marta A; Caltabiano, Marie L
2017-03-01
We investigated whether perfectionism, body image, attachment style, and self-esteem are predictors of orthorexia nervosa. A cohort of 220 participants completed a self-administered, online questionnaire consisting of five measures: ORTO-15, the Multidimensional Perfectionism Scale (MPS), the Multidimensional Body-Self Relations Questionnaire-Appearance Scale (MBSRQ-AS), the Relationship Scales Questionnaire (RSQ), and Rosenberg's Self-Esteem Scale (RSES). Correlation analysis revealed that higher orthorexic tendencies significantly correlated with higher scores for perfectionism (self-oriented, others-oriented and socially prescribed), appearance orientation, overweight preoccupation, self-classified weight, and fearful and dismissing attachment styles. Higher orthorexic tendencies also correlated with lower scores for body areas satisfaction and a secure attachment style. There was no significant correlation between orthorexia nervosa and self-esteem. Multiple linear regression analysis revealed that overweight preoccupation, appearance orientation and the presence of an eating disorder history were significant predictors of orthorexia nervosa with a history of an eating disorder being the strongest predictor. Orthorexia nervosa shares similarities with anorexia nervosa and bulimia nervosa with regards to perfectionism, body image attitudes, and attachment style. In addition, a history of an eating disorder strongly predicts orthorexia nervosa. These findings suggest that these disorders might be on the same spectrum of disordered eating.
Mechanism of dynamic reorientation of cortical microtubules due to mechanical stress.
Muratov, Alexander; Baulin, Vladimir A
2015-12-01
Directional growth caused by gravitropism and corresponding bending of plant cells has been explored since 19th century, however, many aspects of mechanisms underlying the perception of gravity at the molecular level are still not well known. Perception of gravity in root and shoot gravitropisms is usually attributed to gravisensitive cells, called statocytes, which exploit sedimentation of macroscopic and heavy organelles, amyloplasts, to sense the direction of gravity. Gravity stimulus is then transduced into distal elongation zone, which is several mm far from statocytes, where it causes stretching. It is suggested that gravity stimulus is conveyed by gradients in auxin flux. We propose a theoretical model that may explain how concentration gradients and/or stretching may indirectly affect the global orientation of cortical microtubules, attached to the cell membrane and induce their dynamic reorientation perpendicular to the gradients. In turn, oriented microtubule arrays direct the growth and orientation of cellulose microfibrils, forming part of the cell external skeleton and determine the shape of the cell. Reorientation of microtubules is also observed in reaction to light in phototropism and mechanical bending, thus suggesting universality of the proposed mechanism. Copyright © 2015 Elsevier B.V. All rights reserved.
ERIC Educational Resources Information Center
Gormley, Barbara; Lopez, Frederick G.
2010-01-01
This study investigated whether gender, stressful problems common among college students, and adult attachment orientations (anxiety and avoidance) contributed to self-reported perpetration of psychological abuse in dating relationships among 127 college students. College men's stress levels were the strongest predictor of perpetration of…
ERIC Educational Resources Information Center
Scharf, Miri
2014-01-01
The associations between self-perception and attachment orientations and three aspects of children's competence within friendships were examined: "Managing conflict", "seeking support", and "giving support". Questionnaires were completed by 260 4th- and 5th-grade students. Homeroom teachers reported on the children's…
Murdock, Kyle W; Seiler, Annina; Chirinos, Diana A; Garcini, Luz M; Acebo, Sally L; Cohen, Sheldon; Fagundes, Christopher P
2018-04-01
Low subjective social status (SSS) in childhood places one at greater risk of a number of health problems in adulthood. Theoretical and empirical evidence indicates that exposure to supportive parenting may buffer the negative effects of low childhood SSS on adult health. Given the importance of supportive caregivers and close others for the development of attachment orientations throughout the lifespan, attachment theory may be important for understanding why some individuals are resilient to the negative effects of low childhood SSS on adult health while others are not. We examined if attachment anxiety and attachment avoidance altered the association between childhood subjective social status (SSS) and length of telomeres in white blood cells in adulthood. Shorter telomere length is associated with increased risk of age-related diseases including cancer, type 2 diabetes, and cardiovascular disease. Participants (N = 128) completed self-report measures of childhood SSS and attachment orientations, as well as a blood draw. We found that among those with low childhood SSS, low attachment anxiety was associated with longer telomere length in white blood cells in comparison to high attachment anxiety controlling for participant age, sex, race, body mass index, and adult SSS. Among those with high childhood SSS, low attachment anxiety was associated with a slight decrease in telomere length. Attachment avoidance was unrelated to length of telomeres. Such findings provide further evidence for the role that close relationships may have on buffering SSS related health disparities. © 2018 Wiley Periodicals, Inc.
Basic Trust: An Attachment-Oriented Intervention Based on Mind-Mindedness in Adoptive Families
ERIC Educational Resources Information Center
Colonnesi, Cristina; Wissink, Inge B.; Noom, Marc J.; Asscher, Jessica J.; Hoeve, Machteld; Stams, Geert Jan J. M.; Polderman, Nelleke; Kellaert-Knol, Marijke G.
2013-01-01
Objectives: We evaluated a new attachment-oriented intervention aimed at improving parental mind-mindedness, promoting positive parent-child relationships, and reducing child psychopathology in families with adopted children. Method: The sample consisted of 20 families with adopted children (2-5 years of age). After the pretest, the intervention…
Söllner, Wolfgang; Müller, Markus M; Albus, Christian; Behnisch, Rüdiger; Beutel, Manfred E; de Zwaan, Martina; Fritzsche, Kurt; Habermeier, Anita; Hellmich, Martin; Jordan, Jochen; Jünger, Jana; Ladwig, Karl-Heinz; Michal, Matthias; Petrowski, Katja; Ronel, Joram; Stein, Barbara; Weber, Cora; Weber, Rainer; Herrmann-Lingen, Christoph
2018-05-01
The relationship between attachment orientations and the recovery from depressive symptoms in patients diagnosed with coronary artery disease (CAD) with and without a psychotherapeutic intervention was examined in this study. In a multicenter trial of 570 depressed CAD patients (SPIRR-CAD), assigned to usual care plus either a stepwise psychotherapy intervention or one information session, 522 patients provided attachment data at baseline. Attachment was measured with the Relationship Scales Questionnaire (RSQ), yielding four attachment orientations. The primary outcome was change in Hospital Anxiety and Depression Scale depression (HADS-D) scores from baseline to follow-up at 18 months. Secondary outcomes were HADS-D scores at 1, 6, 12, and 24 months. Independent of treatment assignment, attachment was related to change in depression at 18 months (p < 0.01) with secure attachment resulting in a significant reduction (-2.72, SE = 0.27) in depression compared to dismissive-avoidant (-1.51, SE = 0.35, p = 0.040) and fearful-avoidant (-0.65, SE = 0.61, p = 0.012) attachment. Patients with anxious-preoccupied attachment showed changes similar to secure attachment (-2.01, SE = 0.47). An explorative subgroup analysis across all assessment time points revealed patients with a dismissive-avoidant attachment benefitted from psychotherapy (average mean difference = 0.93, SE = 0.47, p = 0.048). Attachment played an important role for improvement in depressive symptoms. Only dismissive-avoidant patients seemed to benefit from the intervention. The lack of improvement in fearful-avoidant patients shows a need for specific interventions for this group. www.clinicaltrials.govNCT00705965; www.isrctn.com ISRCTN76240576. Copyright © 2018 Elsevier Inc. All rights reserved.
Smith, Phillip N; Gamble, Stephanie A; Cort, Natalie A; Ward, Erin A; Conwell, Yeates; Talbot, Nancy L
2012-01-01
The current study examined the interaction of attachment orientation and acute social maladjustment as risk factors for death ideation in a sample of women with Major Depression and histories of childhood sexual abuse. Social maladjustment was associated with greater endorsement of death ideation. Avoidant and anxious attachment orientations moderated the social maladjustment and death ideation associations in some domains. Work-related maladjustment was associated with greater odds of death ideation for those with higher attachment avoidance. Parent-role maladjustment was associated with greater odds of death ideation for those with lower attachment anxiety. Findings demonstrate strong associations between death ideation and social maladjustment, and suggest that death ideation may be specific to certain domains of adjustment for anxious and avoidant attachment styles. © 2011 Wiley Periodicals, Inc.
Children's memories of removal: a test of attachment theory.
Melinder, Annika; Baugerud, Gunn Astrid; Ovenstad, Kristianne Stigsdatter; Goodman, Gail S
2013-02-01
We report a study of parents' attachment orientations and children's autobiographical memory for an experience that according to Bowlby's (1982) attachment theory should be particularly threatening-children's forced separation from their parents. It was hypothesized that individual differences in parents' attachment orientations would be associated with children's distress and memory for this highly traumatic event. Children (n = 28) were observed during forced removal from home or school by Child Protective Services due to allegations of child maltreatment. Children's memory for the removal was tested 1 week later, and biological parents (n = 28) completed an adult attachment measure. Parental attachment anxiety significantly predicted children's distress during less stressful phases of the removal, R(2) = .25, and parents' attachment-related avoidance predicted fewer correct memory reports from the children (i.e., fewer hits to open-ended questions, R(2) = .16, and fewer hits to direct questions, R(2) = .27). The findings indicate that attachment theory provides important guidance for understanding children's autobiographical memory for traumatic events. Copyright © 2013 International Society for Traumatic Stress Studies.
The use of moments of momentum to account for crystal habits
NASA Technical Reports Server (NTRS)
Barber, P. G.
1985-01-01
A three-step theory of crystal growth is proposed which involves first an association of molecules or ions in solution to form an impinging growth unit, then second the orientation of this unit prior to its impact on the surface of a crystal, and finally the attachment of this unit to the crystal face. From this theory the habit of a crystal is dependent upon the moments of momentum of the impinging growth unit. The results of sample calculations are presented or sodium chloride, succinic acid, sucrose, and chromium boride. The faces predicted by this proposed theory are compared with those predicted by other, energy-based calculations and with those experimentally observed. The proposed theory suggests alternative strategies for crystallization and habit modification which may be of technological importance. Listings of the two computer programs that were used are provided.
Attachment orientation and sexual risk behaviour among young Black gay and bisexual men.
Cook, Stephanie H; Watkins, Daphne C; Calebs, Benjamin; Wilson, Patrick A
This mixed methods study used an explanatory sequential design to examine the relationship between attachment and sexual behavior among young Black gay and bisexual men (YBGBM). Cross sectional online surveys and sex diaries were completed by a sample of YBGBM in New York City ( n = 153) to assess the association between adult attachment insecurity and sexual risk behavior. The Experiences in Close Relationships Scale-Revised (ECR-R) was used to assess three types of adult attachment (i.e., secure, anxious, and avoidant). Participants reported condomless sex encounters, as well as serodiscordant condomless anal sex encounters, as measures of sexual risk. Quantitative findings suggested that there were few associations between attachment type and sexual risk behavior; only men with attachment avoidance were likely to engage in condomless sex. However, qualitative findings illuminated some of the social complexities of the association between attachment in childhood, attachment in young adulthood and intimate partnerships, which could be linked to young adult sexual risk behavior. The study findings highlight the need for researchers to further examine the process by which individual differences in attachment orientation are related to YBGBM's sexual behavior.
Xu, Wei; Fu, Zhongfang; He, Li; Schoebi, Dominik; Wang, Jianping
2015-11-30
This study explored whether attachment moderated the relationship between grief and posttraumatic growth. A total of 240 Chinese adults who have lost a family member to cancer reported on their grief (Prolonged Grief Questionnaire-13; PG-13), posttraumatic growth (Posttraumatic Growth Inventory; PTGI) and attachment (Experiences in Close Relationships; ECR). The results suggested that bereaved individuals who scored high on attachment anxiety showed a substantial and positive relationship between grief and posttraumatic growth, while their less anxiously attached counterparts showed no such association. Attachment avoidance was not significantly related to the association between grief and posttraumatic growth. Findings indicated that individuals high in attachment anxiety have the potential to benefit and gain from the process of adapting to the loss. The implications of the results for relevant research and grief counseling were discussed. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Host-Polarized Cell Growth in Animal Symbionts.
Pende, Nika; Wang, Jinglan; Weber, Philipp M; Verheul, Jolanda; Kuru, Erkin; Rittmann, Simon K-M R; Leisch, Nikolaus; VanNieuwenhze, Michael S; Brun, Yves V; den Blaauwen, Tanneke; Bulgheresi, Silvia
2018-04-02
To determine the fundamentals of cell growth, we must extend cell biological studies to non-model organisms. Here, we investigated the growth modes of the only two rods known to widen instead of elongating, Candidatus Thiosymbion oneisti and Thiosymbion hypermnestrae. These bacteria are attached by one pole to the surface of their respective nematode hosts. By incubating live Ca. T. oneisti and T. hypermnestrae with a peptidoglycan metabolic probe, we observed that the insertion of new cell wall starts at the poles and proceeds inward, concomitantly with FtsZ-based membrane constriction. Remarkably, in Ca. T. hypermnestrae, the proximal, animal-attached pole grows before the distal, free pole, indicating that the peptidoglycan synthesis machinery is host oriented. Immunostaining of the symbionts with an antibody against the actin homolog MreB revealed that it was arranged medially-that is, parallel to the cell long axis-throughout the symbiont life cycle. Given that depolymerization of MreB abolished newly synthesized peptidoglycan insertion and impaired divisome assembly, we conclude that MreB function is required for symbiont widening and division. In conclusion, our data invoke a reassessment of the localization and function of the bacterial actin homolog. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.
The Role of Surface Passivation in Controlling Ge Nanowire Faceting.
Gamalski, A D; Tersoff, J; Kodambaka, S; Zakharov, D N; Ross, F M; Stach, E A
2015-12-09
In situ transmission electron microscopy observations of nanowire morphologies indicate that during Au-catalyzed Ge nanowire growth, Ge facets can rapidly form along the nanowire sidewalls when the source gas (here, digermane) flux is decreased or the temperature is increased. This sidewall faceting is accompanied by continuous catalyst loss as Au diffuses from the droplet to the wire surface. We suggest that high digermane flux and low temperatures promote effective surface passivation of Ge nanowires with H or other digermane fragments inhibiting diffusion and attachment of Au and Ge on the sidewalls. These results illustrate the essential roles of the precursor gas and substrate temperature in maintaining nanowire sidewall passivation, necessary to ensure the growth of straight, untapered, ⟨111⟩-oriented nanowires.
Rosario, Margaret; Reisner, Sari L.; Corliss, Heather L.; Wypij, David; Frazier, A. Lindsay; Austin, S. Bryn
2013-01-01
Lesbian, gay, and bisexual youth have elevated rates of depression compared to heterosexuals. We proposed and examined a theoretical model to understand whether attachment and stress paradigms explain disparities in depressive distress by sexual orientation, using the longitudinal Growing Up Today Study (GUTS) and Nurses’ Health Study II (NHSII). GUTS participants eligible for this analysis reported sexual orientation, childhood gender nonconforming behaviors (GNBs), attachment to mother (all in 2005), and depressive symptoms (in 2007). Mothers of the GUTS participants who are the NHSII participants reported attitudes toward homosexuality (in 2004) and maternal affection (in 2006). The sample had 6,122 participants. Of GUTS youth (M = 20.6 years old in 2005; 64.4% female), 1.7% were lesbian/gay (LG), 1.7% bisexual (BI), 10.0% mostly heterosexual (MH), and 86.7% completely heterosexual (CH). After adjusting for demographic characteristics and sibling clustering, LGs, BIs, and MHs reported more depressive distress than CHs. This relation was partially mediated (i.e., explained) for LGs, BIs, and MHs relative to CHs by less secure attachment. A conditional relation (i.e., interaction) indicated that BIs reported more distress than CHs as GNBs increased for BIs; no comparable relation was found for LGs vs. CHs. Sibling comparisons found that sexual minorities (LGs, BIs, and MHs) reported more depressive distress, less secure attachment, and more childhood GNBs than CH siblings; the mothers reported less affection for their sexual-minority than CH offspring. The findings suggest that attachment and childhood gender nonconformity differentially pattern depressive distress by sexual orientation. Attachment and related experiences are more problematic for sexual minorities than for their CH siblings. PMID:23780518
Rosario, Margaret; Reisner, Sari L; Corliss, Heather L; Wypij, David; Frazier, A Lindsay; Austin, S Bryn
2014-07-01
Lesbian, gay, and bisexual (BI) youth have elevated rates of depression compared to heterosexuals. We proposed and examined a theoretical model to understand whether attachment and stress paradigms explain disparities in depressive distress by sexual orientation, using the longitudinal Growing Up Today Study (GUTS) and Nurses' Health Study II (NHSII). GUTS participants eligible for this analysis reported sexual orientation, childhood gender nonconforming behaviors (GNBs), attachment to mother (all in 2005), and depressive symptoms (in 2007). Mothers of the GUTS participants who are the NHSII participants reported attitudes toward homosexuality (in 2004) and maternal affection (in 2006). The sample had 6,122 participants. Of GUTS youth (M = 20.6 years old in 2005; 64.4 % female), 1.7 % were lesbian/gay (LG), 1.7 % bisexual (BI), 10.0 % mostly heterosexual (MH), and 86.7 % completely heterosexual (CH). After adjusting for demographic characteristics and sibling clustering, LGs, BIs, and MHs reported more depressive distress than CHs. This relation was partially mediated (i.e., explained) for LGs, BIs, and MHs relative to CHs by less secure attachment. A conditional relation (i.e., interaction) indicated that BIs reported more distress than CHs as GNBs increased for BIs; no comparable relation was found for LGs versus CHs. Sibling comparisons found that sexual minorities (LGs, BIs, and MHs) reported more depressive distress, less secure attachment, and more childhood GNBs than CH siblings; the mothers reported less affection for their sexual-minority than CH offspring. The findings suggest that attachment and childhood gender nonconformity differentially pattern depressive distress by sexual orientation. Attachment and related experiences are more problematic for sexual minorities than for their CH siblings.
Berant, Ety; Wald, Yaarit
2009-07-01
In this study, we addressed associations between self-reported attachment scales (anxiety and avoidance) and Rorschach (1921/1942) indexes indicating ego-boundary perception (barrier and penetration), use of projective identification, devaluation and splitting defenses, and Comprehensive System (Exner, 2005) scores that represent boundary blurring (incongruous and fabulized combinations). In this study, we extended the sample and findings described by Berant, Mikulincer, Shaver, and Segal (2005) using a nonclinical sample of 89 Israeli adults. We found significant associations between attachment orientations and Rorschach indexes dynamically related to anxiety. We also found a trend toward association between attachment orientation and avoidance. We discuss the theoretical and clinical implications of these findings.
Attachment-Based Family Therapy: A Review of the Empirical Support.
Diamond, Guy; Russon, Jody; Levy, Suzanne
2016-09-01
Attachment-based family therapy (ABFT) is an empirically supported treatment designed to capitalize on the innate, biological desire for meaningful and secure relationships. The therapy is grounded in attachment theory and provides an interpersonal, process-oriented, trauma-focused approach to treating adolescent depression, suicidality, and trauma. Although a process-oriented therapy, ABFT offers a clear structure and road map to help therapists quickly address attachment ruptures that lie at the core of family conflict. Several clinical trials and process studies have demonstrated empirical support for the model and its proposed mechanism of change. This article provides an overview of the clinical model and the existing empirical support for ABFT. © 2016 Family Process Institute.
Exploring Individual Differences in Online Addictions: the Role of Identity and Attachment.
Monacis, Lucia; de Palo, Valeria; Griffiths, Mark D; Sinatra, Maria
2017-01-01
Research examining the development of online addictions has grown greatly over the last decade with many studies suggesting both risk factors and protective factors. In an attempt to integrate the theories of attachment and identity formation, the present study investigated the extent to which identity styles and attachment orientations account for three types of online addiction (i.e., internet addiction, online gaming addiction, and social media addiction). The sample comprised 712 Italian students (381 males and 331 females) recruited from schools and universities who completed an offline self-report questionnaire. The findings showed that addictions to the internet, online gaming, and social media were interrelated and were predicted by common underlying risk and protective factors. Among identity styles, 'informational' and 'diffuse-avoidant' styles were risk factors, whereas 'normative' style was a protective factor. Among attachment dimensions, the 'secure' attachment orientation negatively predicted the three online addictions, and a different pattern of causal relationships were observed between the styles underlying 'anxious' and 'avoidant' attachment orientations. Hierarchical multiple regressions demonstrated that identity styles explained between 21.2 and 30% of the variance in online addictions, whereas attachment styles incrementally explained between 9.2 and 14% of the variance in the scores on the three addiction scales. These findings highlight the important role played by identity formation in the development of online addictions.
Petermann, Holger; Sander, Martin
2013-04-01
Since the 19th century, identification of muscle attachment sites on bones has been important for muscle reconstructions, especially in fossil tetrapods, and therefore has been the subject of numerous biological and paleontological studies. At the microscopic level, in histological thin sections, the only features that can be used reliably for identifying tendon-bone or muscle-tendon-bone interactions are Sharpey's fibers. Muscles, however, do not only attach to the bone indirectly with tendons, but also directly. Previous studies failed to provide new indicators for muscle attachment, or to address the question of whether muscles with direct attachment can be identified histologically. However, histological identification of direct muscle attachments is important because these attachments do not leave visible marks (e.g. scars and rugosities) on the bone surface. We dissected the right hind limb and mapped the muscle attachment sites on the femur of one rabbit (Oryctolagus cuniculus), one Alligator mississippiensis, and one turkey (Meleagris cuniculus). We then extracted the femur and prepared four histological thin sections for the rabbit and the turkey and five histological thin sections for the alligator. Sharpey's fibers, vascular canal orientation, and a frayed periosteal margin can be indicators for indirect but also direct muscle attachment. Sharpey's fibers can be oriented to the cutting plane of the thin section at high angles, and two Sharpey's fibers orientations can occur in one area, possibly indicating a secondary force axis. However, only about 60% of mapped muscle attachment sites could be detected in thin sections, and frequently histological features suggestive of muscle attachment occurred outside mapped sites. While these insights should improve our ability to successfully identify and reconstruct muscles in extinct species, they also show the limitations of this approach. © 2013 The Authors Journal of Anatomy © 2013 Anatomical Society.
Petermann, Holger; Sander, Martin
2013-01-01
Since the 19th century, identification of muscle attachment sites on bones has been important for muscle reconstructions, especially in fossil tetrapods, and therefore has been the subject of numerous biological and paleontological studies. At the microscopic level, in histological thin sections, the only features that can be used reliably for identifying tendon–bone or muscle–tendon-bone interactions are Sharpey's fibers. Muscles, however, do not only attach to the bone indirectly with tendons, but also directly. Previous studies failed to provide new indicators for muscle attachment, or to address the question of whether muscles with direct attachment can be identified histologically. However, histological identification of direct muscle attachments is important because these attachments do not leave visible marks (e.g. scars and rugosities) on the bone surface. We dissected the right hind limb and mapped the muscle attachment sites on the femur of one rabbit (Oryctolagus cuniculus), one Alligator mississippiensis, and one turkey (Meleagris cuniculus). We then extracted the femur and prepared four histological thin sections for the rabbit and the turkey and five histological thin sections for the alligator. Sharpey's fibers, vascular canal orientation, and a frayed periosteal margin can be indicators for indirect but also direct muscle attachment. Sharpey's fibers can be oriented to the cutting plane of the thin section at high angles, and two Sharpey's fibers orientations can occur in one area, possibly indicating a secondary force axis. However, only about 60% of mapped muscle attachment sites could be detected in thin sections, and frequently histological features suggestive of muscle attachment occurred outside mapped sites. While these insights should improve our ability to successfully identify and reconstruct muscles in extinct species, they also show the limitations of this approach. PMID:23439026
NASA Astrophysics Data System (ADS)
Xiao, Yuanhua; Zhao, Xiaobing; Jin, Qingxian; Su, Dangcheng; Wang, Xuezhao; Wu, Shide; Zhou, Liming; Fang, Shaoming
2017-10-01
3D Hierarchical porous cobalt monoxide (CoO) nanoplates with a book-like structure derive from Co(CO3)0.5(OH)·0.11H2O by a two-steps oriented attachment mechanism in the solvothermal process. Firstly, nanoplates are formed by oriented attachment of nanorods. Secondly, new nanoplates could be generated on the old nanoplates by a sloped oriented attachment of nanorods with the based nanoplates shape into a 3D hierarchical book-like structure. The CoO nanoplates show superior specific capacitance about 1221.7 F g-1 at 1 A g-1 to most of the Co-based supercapacitor materials up to date. An asymmetric supercapacitor (ASC) based on positive electrode CoO and negative electrode active carbon (AC) exhibits an excellent energy density of 50.1 Wh kg-1 at a power density of 589 W kg-1 and gets a satisfactory cycling stability (86.3% of its initial capacitance retention at 10 A g-1 over 10 000 cycles).
ERIC Educational Resources Information Center
Clear, Sarah J.; Zimmer-Gembeck, Melanie J.
2017-01-01
Attachment theory and previous research on emotion regulation (ER) suggest that ER will be associated with adult attachment orientation, with the expectation of different associations of attachment avoidance, anxiety, and security with specific ER patterns. In addition, research has shown that the emotion under consideration and the context may…
Intercultural training of medical students.
van Wieringen, J.C.M.; Schulpen, T.W.J.; Kuyvenhoven, M.M.
2001-01-01
Until recently the Utrecht Medical School had a traditional curriculum with a predominantly biomedical orientation and strong emphasis on curative medicine. In 1997 an experimental 'Multi-cultural Family Attachment Course' started at the Utrecht Medical School with 20 second-year medical students. Each student was attached to a native Dutch and an ethnic minority family with a newborn or chronically ill child. In a period of 1.5 years students had to visit each family at home four times. The students monitored growth and development of the child and discussed several aspects of health and disease with the parents according to a structured schedule. In regular group sessions students reported back their experiences. In this way, the influence of socioeconomic circumstances, culture and environment on health becomes a real-life experience. This paper aims to describe some aspects of this pilot-course and the reactions of the students.
ERIC Educational Resources Information Center
Segal, Daniel L.; Needham, Tracy N.; Coolidge, Frederick L.
2009-01-01
The attachment patterns of younger and older adults were studied using two-dimensional self-report measures of adult attachment. Community-dwelling younger (n = 144, M = 22.5 years, SD = 3.6) and older (n = 106, M = 68.6 years, SD = 8.3) adults completed the Measure of Attachment Qualities (MAQ; Carver, 1997) and the Relationship Style…
Ein-Dor, Tsachi; Verbeke, Willem J M I; Mokry, Michal; Vrtička, Pascal
2018-08-01
Attachment in the context of intimate pair bonds is most frequently studied in terms of the universal strategy to draw near, or away, from significant others at moments of personal distress. However, important interindividual differences in the quality of attachment exist, usually captured through secure versus insecure - anxious and/or avoidant - attachment orientations. Since Bowlby's pioneering writings on the theory of attachment, it has been assumed that attachment orientations are influenced by both genetic and social factors - what we would today describe and measure as gene by environment interaction mediated by epigenetic DNA modification - but research in humans on this topic remains extremely limited. We for the first time examined relations between intra-individual differences in attachment and epigenetic modification of the oxytocin receptor (OXTR) and glucocorticoid receptor (NR3C1) gene promoter in 109 young adult human participants. Our results revealed that attachment avoidance was significantly and specifically associated with increased OXTR and NR3C1 promoter methylation. These findings offer first tentative clues on the possible etiology of attachment avoidance in humans by showing epigenetic modification in genes related to both social stress regulation and HPA axis functioning.
Attachment orientation and sexual risk behaviour among young Black gay and bisexual men
Cook, Stephanie H.; Watkins, Daphne C.; Calebs, Benjamin; Wilson, Patrick A.
2016-01-01
This mixed methods study used an explanatory sequential design to examine the relationship between attachment and sexual behavior among young Black gay and bisexual men (YBGBM). Cross sectional online surveys and sex diaries were completed by a sample of YBGBM in New York City (n = 153) to assess the association between adult attachment insecurity and sexual risk behavior. The Experiences in Close Relationships Scale-Revised (ECR-R) was used to assess three types of adult attachment (i.e., secure, anxious, and avoidant). Participants reported condomless sex encounters, as well as serodiscordant condomless anal sex encounters, as measures of sexual risk. Quantitative findings suggested that there were few associations between attachment type and sexual risk behavior; only men with attachment avoidance were likely to engage in condomless sex. However, qualitative findings illuminated some of the social complexities of the association between attachment in childhood, attachment in young adulthood and intimate partnerships, which could be linked to young adult sexual risk behavior. The study findings highlight the need for researchers to further examine the process by which individual differences in attachment orientation are related to YBGBM’s sexual behavior. PMID:27570578
Oriented Attachment Is a Major Control Mechanism To Form Nail-like Mn-Doped ZnO Nanocrystals.
Patterson, Samuel; Arora, Priyanka; Price, Paige; Dittmar, Jasper W; Das, Vijay Kumar; Pink, Maren; Stein, Barry; Morgan, David Gene; Losovyj, Yaroslav; Koczkur, Kallum M; Skrabalak, Sara E; Bronstein, Lyudmila M
2017-12-26
Here, we present a controlled synthesis of Mn-doped ZnO nanoparticles (NPs) with predominantly nail-like shapes, whose formation occurs via tip-to-base-oriented attachment of initially formed nanopyramids, followed by leveling of sharp edges that lead to smooth single-crystalline "nails". This shape is prevalent in noncoordinating solvents such as octadecene and octadecane. Yet, the double bond in the former promotes oriented attachment. By contrast, Mn-doped ZnO NP synthesis in a weakly coordinating solvent, benzyl ether, results in dendritic structures because of random attachment of initial NPs. Mn-doped ZnO NPs possess a hexagonal wurtzite structure, and in the majority of cases, the NP surface is enriched with Mn, indicating a migration of Mn 2+ ions to the NP surface during the NP formation. When the NP formation is carried out without the addition of octadecyl alcohol, which serves as a surfactant and a reaction initiator, large, concave pyramid dimers are formed whose attachment takes place via basal planes. UV-vis and photoluminescence spectra of these NPs confirm the utility of controlling the NP shape to tune electro-optical properties.
Chae, Yoojin; Goodman, Gail S; Edelstein, Robin S
2011-01-01
The authors propose a novel model of autobiographical memory development that features the fundamental role of attachment orientations and negative life events. In the model, it is proposed that early autobiographical memory derives in part from the need to express and remember negative experiences, a need that has adaptive value, and that attachment orientations create individual differences in children's recollections of negative experiences. Specifically, the role of attachment in the processing of negative information is discussed in regard to the mnemonic stages of encoding, storage, and retrieval. This model sheds light on several areas of contradictory data in the memory development literature, such as concerning earliest memories and children's and adults' memory/suggestibility for stressful events.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sushko, M. L.; Rosso, K. M.
Atomic-to-mesoscale simulations were used to reveal the origin of oriented attachment between anatase TiO2 nanoparticles in aqueous HCl solutions. Analysis of the distance and pH dependence of interparticle interactions demonstrates that ion correlation forces are responsible for facet-specific attraction and rotation into lattice co-alignment at long-range. These forces give rise to a metastable solvent separated capture minimum on the disjoining pressure-distance curve, with the barrier to attachment largely due to steric hydration forces from structured intervening solvent.
Shi, Jian; Li, Zhaodong; Kvit, Alexander; Krylyuk, Sergiy; Davydov, Albert V; Wang, Xudong
2013-01-01
Understanding the evolution of amorphous and crystalline phases during atomic layer deposition (ALD) is essential for creating high quality dielectrics, multifunctional films/coatings, and predictable surface functionalization. Through comprehensive atomistic electron microscopy study of ALD TiO2 nanostructures at designed growth cycles, we revealed the transformation process and sequence of atom arrangement during TiO2 ALD growth. Evolution of TiO2 nanostructures in ALD was found following a path from amorphous layers to amorphous particles to metastable crystallites and ultimately to stable crystalline forms. Such a phase evolution is a manifestation of the Ostwald-Lussac Law, which governs the advent sequence and amount ratio of different phases in high-temperature TiO2 ALD nanostructures. The amorphous-crystalline mixture also enables a unique anisotropic crystal growth behavior at high temperature forming TiO2 nanorods via the principle of vapor-phase oriented attachment.
Zhu, Wenzhen; Wang, Chiachih Dc; Chong, Chu Chian
2016-11-01
In the current study, we tested a moderated mediation model in which cultural orientation moderated the mediation model of adult attachment-perceived social support-depressive symptoms, using 2 comparable cross-cultural samples of college students recruited from China and the U.S. (n = 363 for each group). Results indicated that perceived social support mediated the effect of attachment anxiety on depressive symptoms as well as the link between attachment avoidance and depression in both samples. Moderated mediation analyses using PROCESS revealed that interdependent self-construal significantly buffered the indirect effect of attachment avoidance (via perceived social support) on depressive symptoms. The findings indicated significant differences in the mediation models between the U.S. and China groups and interdependent self-construal accounted for the between-country differences. Limitations, implications of the findings, and future research directions are discussed from the perspectives of cross-cultural variation of adult attachment functioning. (PsycINFO Database Record (c) 2016 APA, all rights reserved).
The role of surface passivation in controlling Ge nanowire faceting
Gamalski, A. D.; Tersoff, J.; Kodambaka, S.; ...
2015-11-05
In situ transmission electron microscopy observations of nanowire morphologies indicate that during Au-catalyzed Ge nanowire growth, Ge facets can rapidly form along the nanowire sidewalls when the source gas (here, digermane) flux is decreased or the temperature is increased. This sidewall faceting is accompanied by continuous catalyst loss as Au diffuses from the droplet to the wire surface. We suggest that high digermane flux and low temperatures promote effective surface passivation of Ge nanowires with H or other digermane fragments inhibiting diffusion and attachment of Au and Ge on the sidewalls. Furthermore, these results illustrate the essential roles of themore » precursor gas and substrate temperature in maintaining nanowire sidewall passivation, necessary to ensure the growth of straight, untapered, <111>-oriented nanowires.« less
Therapeutic alliance in schizophrenia: the role of recovery orientation, self-stigma, and insight.
Kvrgic, Sara; Cavelti, Marialuisa; Beck, Eva-Marina; Rüsch, Nicolas; Vauth, Roland
2013-08-30
The present study examined variables related to the quality of the therapeutic alliance in out-patients with schizophrenia. We expected recovery orientation and insight to be positively, and self-stigma to be negatively associated with a good therapeutic alliance. We expected these associations to be independent from age, clinical symptoms (i.e. positive and negative symptoms, depression), and more general aspects of relationship building like avoidant attachment style and the duration of treatment by the current therapist. The study included 156 participants with DSM-IV diagnoses of schizophrenia or schizoaffective disorder in the maintenance phase of treatment. Therapeutic alliance, recovery orientation, self-stigma, insight, adult attachment style, and depression were assessed by self-report. Symptoms were rated by interviewers. Hierarchical multiple regressions revealed that more recovery orientation, less self-stigma, and more insight independently were associated with a better quality of the therapeutic alliance. Clinical symptoms, adult attachment style, age, and the duration of treatment by current therapist were unrelated to the quality of the therapeutic alliance. Low recovery orientation and increased self-stigma might undermine the therapeutic alliance in schizophrenia beyond the detrimental effect of poor insight. Therefore in clinical settings, besides enhancing insight, recovery orientation, and self-stigma should be addressed. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.
Photoswitchable method for the ordered attachment of proteins to surfaces
Camarero, Julio A [Livermore, CA; DeYoreo, James J [Clayton, CA; Kwon, Youngeun [Livermore, CA
2011-07-05
Described herein is a method for the attachment of proteins to any solid support with control over the orientation of the attachment. The method is extremely efficient, not requiring the previous purification of the protein to be attached, and can be activated by UV-light. Spatially addressable arrays of multiple protein components can be generated by using standard photolithographic techniques.
Photoswitchable method for the ordered attachment of proteins to surfaces
Camarero, Julio A.; De Yoreo, James J.; Kwon, Youngeun
2010-04-20
Described herein is a method for the attachment of proteins to any solid support with control over the orientation of the attachment. The method is extremely efficient, not requiring the previous purification of the protein to be attached, and can be activated by UV-light. Spatially addressable arrays of multiple protein components can be generated by using standard photolithographic techniques.
Rodríguez-Navarro, Carlos; Ruiz-Agudo, Encarnación; Harris, Joe; Wolf, Stephan E
2016-11-01
Recent research has shown that biominerals and their biomimetics (i) typically form via an amorphous precursor phase, and (ii) commonly display a nanogranular texture. Apparently, these two key features are closely related, underlining the fact that the formation of biominerals and their biomimetics does not necessarily follow classical crystallization routes, and leaves a characteristic nanotextural imprint which may help to disclose their origins and formation mechanisms. Here we present a general overview of the current theories and models of nonclassical crystallization and their applicability for the advance of our current understanding of biomineralization and biomimetic mineralization. We pay particular attention to the link between nonclassical crystallization routes and the resulting nanogranular textures of biomimetic CaCO 3 mineral structures. After a general introductory section, we present an overview of classical nucleation and crystal growth theories and their limitations. Then, we introduce the Ostwald's step rule as a general framework to explain nonclassical crystallization. Subsequently, we describe nonclassical crystallization routes involving stable prenucleation clusters, dense liquid and solid amorphous precursor phases, as well as current nonclassical crystal growth models. The latter include oriented attachment, mesocrystallization and the new model based on the colloidal growth of crystals via attachment of amorphous nanoparticles. Biomimetic examples of nanostructured CaCO 3 minerals formed via these nonclassical routes are presented which help us to show that colloid-mediated crystal growth can be regarded as a wide-spread growth mechanism. Implications of these observations for the advance in the current understanding on the formation of biomimetic materials and biominerals are finally outlined. Copyright © 2016 Elsevier Inc. All rights reserved.
ERIC Educational Resources Information Center
Allison, Colleen J.; Bartholomew, Kim; Mayseless, Ofra; Dutton, Donald G.
2008-01-01
The authors explored the attachment dynamics of heterosexual couples identified for male partner violence. Based on semistructured interviews, participants were assessed for attachment orientations. Based on a thematic analysis of the interviews, two strategies for regulating distance within these relationships were identified: pursuit and…
ERIC Educational Resources Information Center
Keller, Chad J.; Brown, Chris
2014-01-01
Due to prior research suggesting that relational variables are related to the career development process, we sought to understand how maternal conflictual independence, paternal conflictual independence, attachment anxiety, and attachment avoidance influence the career decision status of Asian American undergraduate students (N = 113). The…
Freitas, Erico T F; Stroppa, Daniel G; Montoro, Luciano A; de Mello, Jaime W V; Gasparon, Massimo; Ciminelli, Virginia S T
2016-09-01
The nature of As-Al-Fe co-precipitates aged for 120 days are investigated in detail by High Resolution Transmission Electron Microscopy (HRTEM), Scanning TEM (STEM), electron diffraction, Energy Dispersive X-Ray Spectroscopy (EDS), Electron Energy-Loss Spectroscopy (EELS), and Energy Filtered Transmission Electron Microscopy (EFTEM). The Al present in magnetite is shown to favour As incorporation (up to 1.10 wt%) relative to Al-free magnetite and Al-goethite, but As uptake by Al-magnetite decreases with increasing Al substitution (3.53-11.37 mol% Al). Arsenic-bearing magnetite and goethite mesocrystals (MCs) are formed by oriented aggregation (OA) of primary nanoparticles (NPs). Well-crystalline magnetite likely formed by Otswald ripening was predominant in the Al-free system. The As content in Al-goethite MCs (having approximately 13% substituted Al) was close to the EDS detection limit (0.1 wt% As), but was below detection in Al-goethites with 23.00-32.19 mol% Al. Our results show for the first time the capacity of Al-magnetite to incorporate more As than Al-free magnetite, and the role of Al in favouring OA-based crystal growth under the experimental conditions, and therefore As retention in the formed MCs. The proposed mechanism of As incorporation involves adsorption of As onto the newly formed NPs. Arsenic is then trapped in the MCs as they grow by self-assembly OA upon attachment of the NPs. We conclude that Al may diffuse to the crystal faces with high surface energy to reduce the total energy of the system during the attachment events, thus favouring the oriented aggregation. Copyright © 2016 Elsevier Ltd. All rights reserved.
Smoot, L M; Pierson, M D
1998-10-01
Attachment of Listeria monocytogenes Scott A to Buna-N rubber and stainless steel under different temperature and pH conditions at the time of cell growth or at the time of attachment was investigated. All experiments were conducted using sterile phosphate buffer to avoid cell growth during exposure to the test surfaces. Numbers of attached cells increased with increasing attachment temperature (10 to 45 degrees C) and exposure time for both test surfaces. Maximum levels of attached cells were obtained when cell growth occurred at 30 degrees C. Downward, but not upward, shifts in the cell suspension holding temperature prior to attachment to Buna-N rubber resulted in reduced adhered cell populations. Maximum levels of adhered cells to Buna-N rubber were not affected by adjustments of the attachment medium pH between 4 and 9. However, after short contact times (i.e., less than 30 min), levels of attached cells were lower when attachment occurred under alkaline conditions. Growth pH was also found to affect the levels of adhered cell populations to Buna-N rubber. L. monocytogenes Scott A attached to stainless steel at higher levels for all temperature and pH parameters evaluated in this study.
Sarracino, Diego; Presaghi, Fabio; Degni, Silvia; Innamorati, Marco
2011-06-01
In early adolescence, attachment security reflects not only the quality of ongoing relationships with parents, but also how adolescents process social relationships with "others" - that is, their "social value orientation" - with possible implications for adolescents' risk-taking. In this study, a sample of Italian early adolescents were administered self-report measures in order to examine the relationships (a) between early adolescents' perceived attachment security to mothers and fathers, social values (related to family and the socio-cultural context), and sensation seeking (as a temperamental predisposition to risk-taking), and (b) between these variables and adolescents' externalizing problem behaviour. Adolescents were more securely attached to the same-sexed parent. Further, attachment security with the opposite-sexed parent predicted more conservative social value orientations, and lower levels of problem behaviour. In contrast, sensation seeking predicted self-enhancement and openness-to-change values to a greater extent, and, in girls, lower levels of attachment security to mothers and fathers. Copyright © 2010 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.
Self-aligning lathe chuck jaws
Peterson, William R.
1982-01-01
A lathe chuck jaw for a lathe chuck having a radially moving actuator which radially moves the jaw in to and out from the workpiece. A jaw base part is rigidly connected to the actuator. A jaw shoe part is rotatably attached to the base part. The shoe part has a workpiece-comforming surface which can hold the workpiece. The rotatable attachment of the shoe part allows it to match the general orientation of the workpiece, including a nonlongitudinal orientation due to a workpiece's imperfect shape.
Self-aligning lathe chuck jaws
Not Available
1980-08-26
A lathe chuck jaw for a lathe chuck having a radially moving actuator which radially moves the jaw into and out from the workpiece is described. A jaw base part is rigidly connected to the actuator. A jaw shoe part is rotatably attached to the base part. The shoe part has a workpiece-conforming surface which can hold the workpiece. The rotatable attachment of the shoe part allows it to match the general orientation of the workpiece, including a nonlongitudinal orientation due to a workpiece's imperfect shape.
Parenthood as a Terror Management Mechanism: The Moderating Role of Attachment Orientations.
Yaakobi, Erez; Mikulincer, Mario; Shaver, Phillip R
2014-06-01
Six studies examined the hypothesis that parenthood serves a terror management function, with effects that are moderated by attachment orientations. In Studies 1 and 2, mortality salience, as compared with control conditions, increased the self-reported vividness and implicit accessibility of parenthood-related cognitions. In Studies 3 and 4, activating parenthood-related thoughts reduced death-thought accessibility and romantic intimacy following mortality salience. In Study 5, heightening the salience of parenthood-related obstacles increased death-thought accessibility. Across the five studies, the effects were significant mainly among participants who scored relatively low on avoidant attachment. In Study 6, avoidant people also reacted to mortality salience with more positive parenthood-related cognitions following an experimental manipulation that made parenthood compatible with their core strivings. Overall, the findings suggest that parenthood can have an anxiety-buffering effect that is moderated by attachment-related avoidance. © 2014 by the Society for Personality and Social Psychology, Inc.
Rosario, Margaret; Reisner, Sari L.; Corliss, Heather L.; Wypij, David; Calzo, Jerel; Austin, S. Bryn
2014-01-01
More lesbian, gay, and bisexual (LGB) youths than heterosexuals report substance use. We examined a theoretical model to understand these disparities in lifetime and past-year substance use by means of stress and attachment paradigms, using the longitudinal Growing Up Today Study (GUTS) and Nurses’ Health Study II (NHSII). GUTS participants are the children of participants in NHSII; thus, child and maternal data are available. In addition, GUTS contains siblings, allowing for comparisons of LGB and heterosexual siblings. Of 5,647 GUTS youths (M = 20.6 years old in 2005), 1.6% were lesbian/gay (LG), 1.6% bisexual (BI), 9.9% mostly heterosexual (MH), and 86.9% completely heterosexual (CH). After adjusting for sibling clustering in GUTS and covariates, significantly more sexual minorities (LGs, BIs, and MHs) than CHs reported lifetime and past-year smoking, non-marijuana illicit drug use, and prescription drug misuse. More sexual minorities also reported marijuana use in the past year. The relations between sexual orientation and substance use were moderated by the stress markers: As mother's discomfort with homosexuality increased, more BIs and MHs than CHs used substances. As childhood gender nonconforming behaviors increased, more LGs than CHs used substances. The relations between sexual orientation and substance use were mediated by attachment and maternal affection (percent of effect mediated ranged from 5.6%–16.8%% for lifetime substance use and 4.9%–24.5% for past-year use). In addition, sibling comparisons found that sexual minorities reported more substance use, more childhood gender nonconforming behaviors, and less secure attachment than CH siblings; mothers reported less affection for their sexual-minority than CH offspring. The findings indicate the importance of stress and attachment paradigms for understanding sexual-orientation disparities in substance use. PMID:25134050
Rosario, Margaret; Reisner, Sari L; Corliss, Heather L; Wypij, David; Calzo, Jerel; Austin, S Bryn
2014-09-01
More lesbian, gay, and bisexual (LGB) youths than heterosexuals report substance use. We examined a theoretical model to understand these disparities in lifetime and past-year substance use by means of stress and attachment paradigms, using the longitudinal Growing Up Today Study (GUTS) and Nurses' Health Study II (NHSII). GUTS participants are the children of participants in NHSII; thus, child and maternal data are available. In addition, GUTS contains siblings, allowing for comparisons of LGB and heterosexual siblings. Of 5,647 GUTS youths (M = 20.6 years old in 2005), 1.6% were lesbian/gay (LG), 1.6% bisexual (BI), 9.9% mostly heterosexual (MH), and 86.9% completely heterosexual (CH). After adjusting for sibling clustering in GUTS and covariates, significantly more sexual minorities (LGs, BIs, and MHs) than CHs reported lifetime and past-year smoking, nonmarijuana illicit drug use, and prescription drug misuse. More sexual minorities also reported marijuana use in the past year. The relations between sexual orientation and substance use were moderated by the stress markers: As mother's discomfort with homosexuality increased, more BIs and MHs than CHs used substances. As childhood gender nonconforming behaviors increased, more LGs than CHs used substances. The relations between sexual orientation and substance use were mediated by attachment and maternal affection (percent of effect mediated ranged from 5.6% to 16.8%% for lifetime substance use and 4.9% to 24.5% for past-year use). In addition, sibling comparisons found that sexual minorities reported more substance use, more childhood gender nonconforming behaviors, and less secure attachment than CH siblings; mothers reported less affection for their sexual minority than CH offspring. The findings indicate the importance of stress and attachment paradigms for understanding sexual-orientation disparities in substance use.
Giannona, Suna; Firkowska, Izabela; Rojas-Chapana, José; Giersig, Michael
2007-01-01
In this study, we describe the spatial organization of CAL-72 osteoblast-like cells on arrays of vertically aligned multi-walled carbon nanotubes (VACNTs). It was observed that, unlike cell growth on non-patterned surfaces, the cell attachment and spreading process on VACNTs was significantly enhanced. Additionally, since carbon nanotubes are known to possess resilient mechanical properties and are chemically stable, the effect of periodic arrays of VACNTs on CAL-72 osteoblast-like cells was also studied. The periodicity and alignment of VACNTs considerably influenced growth, shape and orientation of the cells by steering toward the nanopattern. This situation is of great interest for the potential application of VACNTs in bone bioenginnering. This data provides evidence that CAL-72 osteoblast-like cells can sense physical features at the nanoscale. These results give a fascinating insight into the ways in which cell growth can be influenced by man-made nanostructures and could provide a framework for achieving controlled cell guidance with controlled organization and special physical properties.
Feeney, Brooke C.; Collins, Nancy L.; Van Vleet, Meredith; Tomlinson, Jennifer
2015-01-01
This investigation examined the importance of underlying motivations in predicting secure base support behavior, as well as the extent to which support motivations are predicted by individual differences in attachment orientation. Participants were 189 married couples who participated in two laboratory sessions: During a questionnaire session, couples completed assessments of their underlying motivations for providing, and for not providing, support for their partner's exploration (i.e., goal-strivings), as well as assessments of their typical secure base support behavior. In an observational session, couples engaged in a discussion of one member's personal goals, during which the partner's secure base support was assessed. Results revealed a variety of distinct motivations for providing, and for not providing, secure base support to one's partner, as well as theoretically expected links between these motivations and both secure base behavior and attachment orientation. This work establishes motivations as important mechanisms that underlie the effective or ineffective provision of relational support. PMID:23581972
Borelli, Jessica L.; Sbarra, David A.; Randall, Ashley K.; Snavely, Jonathan E.; St. John, Heather K.; Ruiz, Sarah K.
2013-01-01
Military deployment affects thousands of families each year, yet little is known about its impact on non-deployed spouses (NDSs) and romantic relationships. This report examines two factors–attachment security and a communal orientation with respect to the deployment– that may be crucial to successful dyadic adjustment by the NDS. Thirty-seven female NDSs reported on their relationship satisfaction before and during their partner’s deployment, and 20 also did so two weeks following their partner’s return. Participants provided a stream-of-conscious speech sample regarding their relationship during the deployment; linguistic coding of sample transcripts provided measures of each participant’s (a) narrative coherence, hypothesized to reflect attachment security with respect to their deployed spouse; and, (b) frequency of first person plural pronoun use (we-talk), hypothesized to reflect a communal orientation to coping. More frequent first person plural pronouns— we-talk— was uniquely associated with higher relationship satisfaction during the deployment, and greater narrative coherence was uniquely associated with higher relationship satisfaction post-deployment. Discussion centers on the value of relationship security and communal orientations in predicting how couples cope with deployment and other types of relationship stressors. PMID:24033247
2015-01-01
Abstract Social networking sites (SNSs) can be beneficial tools for users to gain social capital. Although social capital consists of emotional and informational resources accumulated through interactions with strong or weak social network ties, the existing literature largely ignores attachment style in this context. This study employed attachment theory to explore individuals' attachment orientations toward Facebook usage and toward online and offline social capital. A university student sample (study 1) and a representative national sample (study 2) showed consistent results. Secure attachment was positively associated with online bonding and bridging capital and offline bridging capital. Additionally, secure attachment had an indirect effect on all capital through Facebook time. Avoidant attachment was negatively associated with online bonding capital. Anxious–ambivalent attachment had a direct association with online bonding capital and an indirect effect on all capital through Facebook. Interaction frequency with good friends on Facebook positively predicted all online and offline capital, whereas interaction frequency with average friends on Facebook positively predicted online bridging capital. Interaction frequency with acquaintances on Facebook was negatively associated with offline bonding capital. The study concludes that attachment style is a significant factor in guiding social orientation toward Facebook connections with different ties and influences online social capital. The study extends attachment theory among university students to a national sample to provide more generalizable evidence for the current literature. Additionally, this study extends attachment theory to the SNS setting with a nuanced examination of types of Facebook friends after controlling extraversion. Implications for future research are discussed. PMID:25751049
Lin, Jih-Hsuan
2015-03-01
Social networking sites (SNSs) can be beneficial tools for users to gain social capital. Although social capital consists of emotional and informational resources accumulated through interactions with strong or weak social network ties, the existing literature largely ignores attachment style in this context. This study employed attachment theory to explore individuals' attachment orientations toward Facebook usage and toward online and offline social capital. A university student sample (study 1) and a representative national sample (study 2) showed consistent results. Secure attachment was positively associated with online bonding and bridging capital and offline bridging capital. Additionally, secure attachment had an indirect effect on all capital through Facebook time. Avoidant attachment was negatively associated with online bonding capital. Anxious-ambivalent attachment had a direct association with online bonding capital and an indirect effect on all capital through Facebook. Interaction frequency with good friends on Facebook positively predicted all online and offline capital, whereas interaction frequency with average friends on Facebook positively predicted online bridging capital. Interaction frequency with acquaintances on Facebook was negatively associated with offline bonding capital. The study concludes that attachment style is a significant factor in guiding social orientation toward Facebook connections with different ties and influences online social capital. The study extends attachment theory among university students to a national sample to provide more generalizable evidence for the current literature. Additionally, this study extends attachment theory to the SNS setting with a nuanced examination of types of Facebook friends after controlling extraversion. Implications for future research are discussed.
Fiedler, Kathrin
2015-01-01
Functional morphology and biomechanical properties of hook structures functioning as attachment devices in the leaning climbers Rosa arvensis, Rosa arvensis ‘Splendens‘, Asparagus falcatus and Asparagus setaceus are analysed in order to investigate the variability in closely related species as well as convergent developments of hook structure and properties in distant systematic lineages (monocots and dicots). Prickles and spines were characterised by their size, orientation and the maximum force measured at failure in mechanical tests performed with traction forces applied at different angles. In Rosa arvensis and Rosa arvensis ‘Splendens‘ three types of prickles differing largely in geometrical and mechanical properties are identified (prickles of the wild species and two types of prickles in the cultivar). In prickles of Rosa arvensis no particular orientation of the prickle tip is found whereas in the cultivar Rosa arvensis ‘Splendens‘ prickles gradually gain a downward-orientation due to differential growth in the first weeks of their development. Differences in mechanical properties and modes of failure are correlated to geometrical parameters. In Asparagus falcatus and Asparagus setaceus spines are composed of leaf tissue, stem tissue and tissue of the axillary bud. Between species spines differ in size, orientation, distribution along the stem, tissue contributions and mechanical properties. The prickles of Rosa arvensis and its cultivar and the spines of the studied Asparagus species have several traits in common: (1) a gradual change of cell size and cell wall thickness, with larger cells in the centre and smaller thick-walled cells at the periphery of the hooks, (2) occurrence of a diversity of shape and geometry within one individual, (3) failure of single hooks when submitted to moderate mechanical stresses (Fmax/basal area < 35 N/mm²) and (4) failure of the hooks without severe stem damage (at least in the tested wild species). PMID:26629690
Gallenmüller, Friederike; Feus, Amélie; Fiedler, Kathrin; Speck, Thomas
2015-01-01
Functional morphology and biomechanical properties of hook structures functioning as attachment devices in the leaning climbers Rosa arvensis, Rosa arvensis 'Splendens', Asparagus falcatus and Asparagus setaceus are analysed in order to investigate the variability in closely related species as well as convergent developments of hook structure and properties in distant systematic lineages (monocots and dicots). Prickles and spines were characterised by their size, orientation and the maximum force measured at failure in mechanical tests performed with traction forces applied at different angles. In Rosa arvensis and Rosa arvensis 'Splendens' three types of prickles differing largely in geometrical and mechanical properties are identified (prickles of the wild species and two types of prickles in the cultivar). In prickles of Rosa arvensis no particular orientation of the prickle tip is found whereas in the cultivar Rosa arvensis 'Splendens' prickles gradually gain a downward-orientation due to differential growth in the first weeks of their development. Differences in mechanical properties and modes of failure are correlated to geometrical parameters. In Asparagus falcatus and Asparagus setaceus spines are composed of leaf tissue, stem tissue and tissue of the axillary bud. Between species spines differ in size, orientation, distribution along the stem, tissue contributions and mechanical properties. The prickles of Rosa arvensis and its cultivar and the spines of the studied Asparagus species have several traits in common: (1) a gradual change of cell size and cell wall thickness, with larger cells in the centre and smaller thick-walled cells at the periphery of the hooks, (2) occurrence of a diversity of shape and geometry within one individual, (3) failure of single hooks when submitted to moderate mechanical stresses (Fmax/basal area < 35 N/mm²) and (4) failure of the hooks without severe stem damage (at least in the tested wild species).
[Time perception, maternal tasks, and maternal role behavior among pregnant Japanese women].
Yamamoto, A
1996-01-01
The relationship of time perception, maternal tasks, and maternal role behavior was examined in 140 pregnant Japanese women with a short-term longitudinal design. A model developed by Rubin provided the conceptual framework for this research. The Time Perception Scale. Time Production Method, and the Prefatory Maternal Response measured the study variables. Study results revealed significant differences in duration of time, time production, maternal-fetal attachment, and maternal role behavior before and after quickening(fetal movement)occurred. Medium to strong positive relationships among time orientation, maternal-fetal attachment, gratification, and maternal role behavior were found before and after movement. After quickening, a weak relationship between time orientation and duration was found. After controlling maternal-fetal attachment and gratification in pregnancy and maternal role, orientation in time perception accounted for significant amounts of variance in maternal role behavior before and after fetal movement. Results show that the process of becoming a mother, which started before quickening, increased in magnitude after fetal movement. The function of fetal movement is important in developing motherhood. In the process of becoming a mother, cognitive, emotional, and behavioral aspects in becoming a mother are inseparable from each other. Future orientation of time perception contributes to development of maternal role behavior. Having a future orientation during pregnancy may indicate hope or positive expectation. Based on these findings, several recommendations were proposed: (a)to study further the general process of becoming a mother and the role of time perception in developing motherhood, (b)to disseminate information to the general public about the process in development of motherhood, (c)to construct theory to explain the process of becoming a mother, and(d)to conduct future research to clarify the construct of time perception and attachment.
Carnelley, Katherine B; Boag, Elle M
2018-04-16
There is a paucity of research that examines prejudice from an attachment theory perspective. Herein we make theoretical links between attachment patterns and levels of prejudice. Perceptions of outgroup threat, which activate the attachment system, are thought to lead to fear and prejudice for those high in attachment anxiety, and to distancing and prejudice for those high in attachment avoidance. We review the literature that examines the associations between attachment patterns and prejudice; evidence from attachment priming studies suggests a causal role of attachment security in reducing prejudice. We identify several mediators of these links: empathy, negative emotions, trust, social dominance orientation, romanticism, and contact quality. Future research should manipulate potential mediators and use psychophysiological assessments of threat. Copyright © 2018 Elsevier Ltd. All rights reserved.
Kague, E; Witten, P E; Soenens, M; Campos, C L; Lubiana, T; Fisher, S; Hammond, C; Brown, K Robson; Passos-Bueno, M R; Huysseune, A
2018-03-15
The capacity to fully replace teeth continuously makes zebrafish an attractive model to explore regeneration and tooth development. The requirement of attachment bone for the appearance of replacement teeth has been hypothesized but not yet investigated. The transcription factor sp7 (osterix) is known in mammals to play an important role during odontoblast differentiation and root formation. Here we study tooth replacement in the absence of attachment bone using sp7 zebrafish mutants. We analysed the pattern of tooth replacement at different stages of development and demonstrated that in zebrafish lacking sp7, attachment bone is never present, independent of the stage of tooth development or fish age, yet replacement is not interrupted. Without bone of attachment we observed abnormal orientation of teeth, and abnormal connection of pulp cavities of predecessor and replacement teeth. Mutants lacking sp7 show arrested dentinogenesis, with non-polarization of odontoblasts and only a thin layer of dentin deposited. Osteoclast activity was observed in sp7 mutants; due to the lack of bone of attachment, remodelling was diminished but nevertheless present along the pharyngeal bone. We conclude that tooth replacement is ongoing in the sp7 mutant despite poor differentiation and defective attachment. Without bone of attachment tooth orientation and pulp organization are compromised. Copyright © 2018 Elsevier Inc. All rights reserved.
On the Relationship between Value Orientation, Valences, and Academic Achievement
ERIC Educational Resources Information Center
Fries, Stefan; Schmid, Sebastian; Hofer, Manfred
2007-01-01
Value orientations are believed to influence learning in school. We assume that this influence is mediated by the valences attached to specific school subjects. In a questionnaire study (704 students from 36 classes) achievement and well-being value orientations were measured. Students also rated valence scales for the school subjects German and…
Attachment and growth of human keratinocytes in a serum-free environment.
Gilchrest, B A; Calhoun, J K; Maciag, T
1982-08-01
Using a serum-free system, we have investigated the influence of human fibronectin (HFN) and selected growth factors (GF) on the attachment and growth of normal human keratinocytes in vitro. Single-cell suspensions of keratinocytes from near-confluent primary plates, plated on 5-10 microgram/cm2 HFN, showed approximately 30-40% attachment after 2-24 hours of incubation at 37 degrees C, compared with 4-6% attachment on uncoated platic plates. Percentage of attached cells was independent of seed density, tissue donor age, in vitro culture age, or medium composition, while subsequent cellular proliferation was strongly dependent on these factors. Keratinocytes grown on an adequate HFN matrix in a previously described hormone-supplemented medium (Maciag et al., 1981a) achieved four to eight population doubling over 7-12 days at densities greater than or equal to 104 cell/cm2. Removal of most GF individually from the medium had little or no effect on growth, while removal of epidermal growth factor (EGF) alone reduced growth by 30-35% and removal of bovine brain extract (BE) alone reduced growth by approximately 90%. Conversely, EGF alone in basal medium supported approximately 10% control growth, BE alone supported 30-40% control growth, and the combination of EGF and BE approximately 70%. In addition to its major effect on proliferation in this system, BE was necessary to preserve normal keratinocyte morphology and protein production. These findings expand earlier observations that HFN facilitates keratinocyte attachment in vitro and that a brain-derived extract can exert a major positive influence on cultured keratinocytes.
Effect of Crystal Orientation on Analysis of Single-Crystal, Nickel-Based Turbine Blade Superalloys
NASA Technical Reports Server (NTRS)
Swanson, G. R.; Arakere, N. K.
2000-01-01
High-cycle fatigue-induced failures in turbine and turbopump blades is a pervasive problem. Single-crystal nickel turbine blades are used because of their superior creep, stress rupture, melt resistance, and thermomechanical fatigue capabilities. Single-crystal materials have highly orthotropic properties making the position of the crystal lattice relative to the part geometry a significant and complicating factor. A fatigue failure criterion based on the maximum shear stress amplitude on the 24 octahedral and 6 cube slip systems is presented for single-crystal nickel superalloys (FCC crystal). This criterion greatly reduces the scatter in uniaxial fatigue data for PWA 1493 at 1,200 F in air. Additionally, single-crystal turbine blades used in the Space Shuttle main engine high pressure fuel turbopump/alternate turbopump are modeled using a three-dimensional finite element (FE) model. This model accounts for material orthotrophy and crystal orientation. Fatigue life of the blade tip is computed using FE stress results and the failure criterion that was developed. Stress analysis results in the blade attachment region are also presented. Results demonstrate that control of crystallographic orientation has the potential to significantly increase a component's resistance to fatigue crack growth without adding additional weight or cost.
Correlates of Psychological Abuse Perpetration in College Dating Relationships
ERIC Educational Resources Information Center
Gormley, Barbara; Lopez, Frederick G.
2010-01-01
This study examined the contributions of gender, adult romantic attachment orientations (i.e., avoidance, anxiety), defense mechanisms (i.e., narcissism, other-splitting), and stressors to college student psychological abuse perpetration (dominance). Men with higher levels of attachment avoidance, narcissistic entitlement, and stressful problems…
Aurora A kinase contributes to a pole-based error correction pathway
Ye, Anna A.; Deretic, Jovana; Hoel, Christopher M.; Hinman, Albert W.; Cimini, Daniela; Welburn, Julie P.; Maresca, Thomas J.
2015-01-01
Summary Chromosome biorientation, where sister kinetochores attach to microtubules (MTs) from opposing spindle poles, is the configuration that best ensures equal partitioning of the genome during cell division. Erroneous kinetochore-microtubule (kt-MT) attachments are commonplace but often corrected prior to anaphase [1, 2]. Error correction, thought to be mediated primarily by the centromere-enriched Aurora B kinase (ABK) [3-5], typically occurs near spindle poles [6]; albeit, the relevance of this locale is unclear. Furthermore, polar ejection forces (PEFs), highest near poles [7], can stabilize improper attachments by pushing mal-oriented chromosome arms away from spindle poles [8, 9]. Hence, a conundrum: erroneous kt-MT attachments are weakened where PEFs are most likely to strengthen them. Here, we report that Aurora A kinase (AAK) opposes the stabilizing effect of PEFs. AAK activity contributes to phosphorylation of kinetochore substrates near poles and its inhibition results in chromosome mis-alignment and an increased incidence of erroneous kt-MT attachments. Furthermore, AAK directly phosphorylates a site in the N-terminal tail of Ndc80/Hec1 that has been implicated in reducing the affinity of the Ndc80 complex for MTs when phosphorylated [10-12]. We propose that an AAK activity gradient contributes to correcting mal-oriented kt-MT attachments in the vicinity of spindle poles. PMID:26166783
Childbirth Pain, Attachment Orientations, and Romantic Partner Support During Labor and Delivery.
Wilson, Carol L; Simpson, Jeffry A
2016-12-01
Attachment anxiety is associated with greater perceived physical pain, whereas social support is associated with lower pain perceptions. Few studies, however, have examined the joint effects of attachment and support on acute physical pain in a dyadic context. In this study, first-time expectant mothers ( N =140) and their male partners completed romantic attachment measures (prenatally) and postnatal assessments of women's pain and men's emotional support during labor and delivery. More securely attached women benefited from emotional support in terms of reduced pain, more avoidantly attached women reported greater pain when given more support, and more anxiously attached women reported greater pain, regardless of their partner's support. These results advance our understanding of which women are most vulnerable to painful childbirth.
The method of attachment influences accelerometer-based activity data in dogs.
Martin, Kyle W; Olsen, Anastasia M; Duncan, Colleen G; Duerr, Felix M
2017-02-10
Accelerometer-based activity monitoring is a promising new tool in veterinary medicine used to objectively assess activity levels in dogs. To date, it is unknown how device orientation, attachment method, and attachment of a leash to the collar holding an accelerometer affect canine activity data. It was our goal to evaluate whether attachment methods of accelerometers affect activity counts. Eight healthy, client-owned dogs were fitted with two identical neck collars to which two identical activity monitors were attached using six different methods of attachment. These methods of attachment evaluated the use of a protective case, positioning of the activity monitor and the tightness of attachment of the accelerometer. Lastly, the effect of leash attachment to the collar was evaluated. For trials where the effect of leash attachment to the collar was not being studied, the leash was attached to a harness. Activity data obtained from separate monitors within a given experiment were compared using Pearson correlation coefficients and across all experiments using the Kruskal-Wallis Test. There was excellent correlation and low variability between activity monitors on separate collars when the leash was attached to a harness, regardless of their relative positions. There was good correlation when activity monitors were placed on the same collar regardless of orientation. There were poor correlations between activity monitors in three experiments: when the leash was fastened to the collar that held an activity monitor, when one activity monitor was housed in the protective casing, and when one activity monitor was loosely zip-tied to the collar rather than threaded on using the provided metal loop. Follow-up, pair-wise comparisons identified the correlation associated with these three methods of attachment to be statistically different from the level of correlation when monitors were placed on separate collars. While accelerometer-based activity monitors are useful tools to objectively assess physical activity in dogs, care must be taken when choosing a method to attach the device. The attachment of the activity monitor to the collar should utilize a second, dedicated collar that is not used for leash attachment and the attachment method should remain consistent throughout a study period.
Strategic orientations of small multihospital systems.
Luke, R D; Begun, J W
1988-01-01
Strategic behaviors of organizations can be classified along two dimensions--growth orientations, or patterns of evolution over time, and action orientations, or strategic aggressiveness in undertaking a particular growth orientation. We create measures of growth and action orientations for small multihospital systems and test the validity of the growth and action orientation typologies, using data from a sample of small multihospital systems. Growth and action orientations do appear to exist independently of each other, and they are related to the ownership status of the systems. Not-for-profit and church-other systems exhibit similar strategic orientations, unlike those of Catholic and investor-owned systems. PMID:3060448
Links between an Owner’s Adult Attachment Style and the Support-Seeking Behavior of Their Dog
Rehn, Therese; Beetz, Andrea; Keeling, Linda J.
2017-01-01
The aim of this study was to investigate if an owner’s adult attachment style (AAS) influences how their dog interacts and obtains support from them during challenging events. A person’s AAS describes how they perceive their relationship to other people, but it may also reflect their caregiving behavior, and so their behavior toward the dog. We measured the AAS of 51 female Golden retriever owners, using the Adult Attachment Style Questionnaire (ASQ), and observed the reactions of the dog-owner dyads in response to different challenging situations [visual surprise, auditory stressor and social stressors like a person approaching dressed as ghost or in coat, hat and sunglasses]. In addition, the dog was left alone in a novel environment for 3 min. Interactions between the dog and owner were observed both before and after separation. Spearman rank correlation tests were made (between owner AAS and dog behavior) and where correlations were found, Mann–Whitney U-tests were made on the dogs’ behavioral response between high and low scoring groups of owners of the different subscales of the ASQ. The more secure the owner (ASQ subscale ‘Confidence’), the longer the dog was oriented to the two sudden stressors (the visual and auditory stressor). The more anxious the owner (ASQ subscale ‘Attachment anxiety’), the longer the dog oriented toward the owner during the approach of the strange-looking person and the dog showed less lip licking during separation from the owner. The more avoidant the owner (ASQ subscale ‘Avoidant attachment’), the longer the dog oriented toward the owner during the visual stressor, the less it was located behind the owner during the auditory stressor and the less it was oriented toward the auditory stressor. These links between owner attachment style and dog behavior imply that dogs may develop different strategies to handle challenging situations, based on the type of support they get from their owner. PMID:29250009
Hsiao, Sheng-Wen; Venault, Antoine; Yang, Hui-Shan; Chang, Yung
2014-06-01
Three well-defined diblock copolymers made of poly(sulfobetaine methacrylate) (poly(SBMA)) and poly(propylene oxide) (PPO) groups were synthesized by atom transfer radical polymerization (ATRP) method. They were physically adsorbed onto three types of surfaces having different topography, including smooth flat surface, convex surface, and indented surface. Chemical state of surfaces was characterized by XPS while the various topographies were examined by SEM and AFM. Hydrophilicity of surfaces was dependent on both the surface chemistry and the surface topography, suggesting that orientation of copolymer brushes can be tuned in the design of surfaces aimed at resisting bacterial attachment. Escherichia coli, Staphylococcus epidermidis, Streptococcus mutans and Escherichia coli with green fluorescent protein (E. coli GFP) were used in bacterial tests to assess the resistance to bacterial attachment of poly(SBMA)-covered surfaces. Results highlighted a drastic improvement of resistance to bacterial adhesion with the increasing of poly(SBMA) to PPO ratio, as well as an important effect of surface topography. The chemical effect was directly related to the length of the hydrophilic moieties. When longer, more water could be entrapped, leading to improved anti-bacterial properties. The physical effect impacted on the orientation of the copolymer brushes, as well as on the surface contact area available. Convex surfaces as well as indented surfaces wafer presented the best resistance to bacterial adhesion. Indeed, bacterial attachment was more importantly reduced on these surfaces compared with smooth surfaces. It was explained by the non-orthogonal orientation of copolymer brushes, resulting in a more efficient surface coverage of zwitterionic molecules. This work suggests that not only the control of surface chemistry is essential in the preparation of surfaces resisting bacterial attachment, but also the control of surface topography and orientation of antifouling moieties. Copyright © 2014 Elsevier B.V. All rights reserved.
Infant-Mother Attachment and the Growth of Externalizing Problems across the Primary-School Years
ERIC Educational Resources Information Center
Pasco Fearon, R. M.; Belsky, Jay
2011-01-01
Background: Some contend that attachment insecurity increases risk for the development of externalizing behavior problems in children. Method: Latent-growth curve analyses were applied to data on 1,364 children from the NICHD Study of Early Child Care to evaluate the association between early attachment and teacher-rated externalizing problems…
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wu, Zhigang; Chun, Jaehun; Chatterjee, Sayandev
Detailed knowledge of the forces between nanocrystals is very crucial for understanding many generic (e.g., random aggregation/assembly and rheology) and specific (e.g., oriented attachment) phenomena at macroscopic length scales, especially considering the additional complexities involved in nanocrystals such as crystal orientation and corresponding orientation-dependent physicochemical properties. Because there are a limited number of methods to directly measure the forces, little is known about the forces that drive the various emergent phenomena. Here we report on two methods of preparing crystals as force measurement tips used in an atomic force microscope (AFM): the focused ion beam method and microlithography method. Themore » desired crystals are fabricated using these two methods and are fixed to the AFM probe using platinum deposition, ultraviolet epoxy, or resin, which allows for the orientation-dependent force measurements. These two methods can be used to attach virtually any solid particles (from the size of a few hundreds of nanometers to millimeters). We demonstrate the force measurements between aqueous media under different conditions such as pH.« less
Oesterreich, Steffi
2003-11-01
Scaffold attachment factor B1 (SAFB1) and SAFB2 are large, multifunctional proteins that have been implicated in numerous cellular processes including chromatin organization, transcriptional regulation, RNA splicing, and stress response. While the two homologous proteins show high similarity, and functional domains are highly conserved, evidence suggests that they also have unique properties. For example, SAFB2 can be found in both the nucleus and cytoplasm, whereas SAFB1 seems to be mainly localized in the nucleus. In breast cancer cells, SAFBs function as estrogen receptor corepressors and growth inhibitors. SAFB protein expression is lost in approximately 20% of breast cancers. Interestingly, the two genes reside in close proximity, oriented head-to-head, on chromosome 19p13, a locus which is frequently lost in clinical breast cancer specimens. Furthermore, SAFB1 mutations have been identified in breast tumors that were not present in adjacent normal tissue. The possibility that SAFB1 and SAFB2 are novel breast tumor suppressor genes, and how they might function in this role, are discussed. Copyright 2003 Wiley-Liss, Inc.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Liu, Lili; Zhang, Shuai; Bowden, Mark E.
Barium tungstate (BaWO 4) is a widely investigated inorganic optical material due to its attractive emission properties. Because those properties strongly depend on crystal structure and morphology, numerous approaches to controlling growth have been pursued. However, an understanding of the growth mechanisms that lead to the wide range of morphologies obtained to date is largely lacking, and most attempts to develop that understanding have been based on post-growth analyses. Significantly, such analyses have led to the conclusion that certain BaWO 4 crystal morphologies result from a nonclassical growth process of oriented attachment. In this work, we systematically varied the morphologymore » of BaWO 4 crystals by adjusting the relative concentrations of solute, water, and ethanol. We then explored the growth mechanism leading to the observed range of morphologies through in situ TEM and in situ AFM. We find that even the most complex BaWO 4 morphologies occur through purely classical growth mechanisms largely controlled by the content of solute and ethanol. The latter acts as an impurity to poison growth at low concentrations and low solute levels, but leads to development of growth instabilities and eventual dendritic growth at high alcohol and moderate solute concentrations by driving up the supersaturation. These findings also highlight the necessity of in situ experiments to interpret ex situ observations of crystal growth and decipher the controlling mechanisms.« less
George, Carol; Buchheim, Anna
2014-01-01
The following case study is presented to facilitate an understanding of how the attachment information evident from Adult Attachment Projective Picture System (AAP) assessment can be integrated into a psychodynamic perspective in making therapeutic recommendations that integrate an attachment perspective. The Adult Attachment Projective Picture System (AAP) is a valid representational measure of internal representations of attachment based on the analysis of a set of free response picture stimuli designed to systematically activate the attachment system (George and West, 2012). The AAP provides a fruitful diagnostic tool for psychodynamic-oriented clinicians to identify attachment-based deficits and resources for an individual patient in therapy. This paper considers the use of the AAP with a traumatized patient in an inpatient setting and uses a case study to illustrate the components of the AAP that are particularly relevant to a psychodynamic conceptualization. The paper discusses also attachment-based recommendations for intervention. PMID:25140164
Childbirth Pain, Attachment Orientations, and Romantic Partner Support During Labor and Delivery
Wilson, Carol L.; Simpson, Jeffry A.
2016-01-01
Attachment anxiety is associated with greater perceived physical pain, whereas social support is associated with lower pain perceptions. Few studies, however, have examined the joint effects of attachment and support on acute physical pain in a dyadic context. In this study, first-time expectant mothers (N=140) and their male partners completed romantic attachment measures (prenatally) and postnatal assessments of women’s pain and men’s emotional support during labor and delivery. More securely attached women benefited from emotional support in terms of reduced pain, more avoidantly attached women reported greater pain when given more support, and more anxiously attached women reported greater pain, regardless of their partner’s support. These results advance our understanding of which women are most vulnerable to painful childbirth. PMID:28529444
Mata, Marcia M; da Silva, Wladimir P; Wilson, Richard; Lowe, Edwin; Bowman, John P
2015-02-06
Contamination of industrial and domestic food usage environments by the attachement of bacterial food-borne pathogen Listeria monocytogenes has public health and economic implications. Comprehensive proteomics experiments using label-free liquid chromatography/tandem mass spectrometry were used to compare the proteomes of two different L. monocytogenes strains (Siliken_1/2c and F2365_4b), which show very different capacities to attach to surfaces. Growth temperature and strain type were highly influential on the proteomes in both attached and planktonic cells. On the basis of the proteomic data, it is highly unlikely that specific surface proteins play a direct role in adherence to inanimate surfaces. Instead, strain-dependent responses related to cell envelope polymer biosynthesis and stress response regulation likely contribute to a different ability to attach and also to survive external stressors. Collectively, the divergent proteome-level responses observed define strain- and growth-temperature-dependent differences relevant to attachment efficacy, highlight relevant proteins involved in stress protection in attached cells, and suggest that strain differences and growth conditions are important in relation to environmental persistence.
Starks, Tyrel J; Castro, Michael A; Castiblanco, Juan P; Millar, Brett M
2017-05-01
The existing literature has identified that beliefs about the interpersonal meaning of condom use are a significant predictor of condomless anal sex (CAS). Some have suggested that condom use in this context may function as a form of nonverbal communication. This study utilized attachment theory as a framework and tested a hypothesized model linking adult attachment to CAS through communication skills and condom expectancies. An online survey was completed by 122 single, HIV-negative gay and bisexual (GB) men living in the U.S. They completed measures of adult attachment (anxious and avoidant), condom expectancies regarding intimacy and pleasure interference, communication skills, self-assessed mate value, and recent CAS with casual partners. There was a significant, positive bivariate association between anxious attachment and receptive CAS. In path model analyses, two over-arching pathways emerged. In the other-oriented pathway, anxious attachment, self-perceived mate value, and emotional communication predicted the belief that condoms interfere with intimacy. In turn, intimacy interference expectancies were positively associated with the odds of receptive CAS. In the self-oriented pathway, assertive communication skills mediated a link between avoidant attachment and the belief that condoms interfere with sexual pleasure. Pleasure interference expectancies were positively associated with the odds of insertive CAS. The findings highlight the importance of relational or interpersonal concerns in sexual risk-taking among single GB men. Attachment theory may serve as a framework for organizing these interpersonal correlates of CAS. Results are consistent with the conceptualization of condom use as a form of nonverbal attachment-related behavior. Implications for sexual health and risk-reduction interventions are explored in this context.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kim, Dong Hoe; Park, Jaehong; Li, Zhen
Organic-inorganic perovskites with intriguing optical and electrical properties have attracted significant research interests due to their excellent performance in optoelectronic devices. Recent efforts on preparing uniform and large-grain polycrystalline perovskite films have led to enhanced carrier lifetime up to several microseconds. However, the mobility and trap densities of polycrystalline perovskite films are still significantly behind their single-crystal counterparts. Here, a facile topotactic-oriented attachment (TOA) process to grow highly oriented perovskite films, featuring strong uniaxial-crystallographic texture, micrometer-grain morphology, high crystallinity, low trap density (≈4 x 10 14 cm -3), and unprecedented 9 GHz charge-carrier mobility (71 cm 2 V -1 smore » -1), is demonstrated. TOA-perovskite-based n-i-p planar solar cells show minimal discrepancies between stabilized efficiency (19.0%) and reverse-scan efficiency (19.7%). In conclusion, the TOA process is also applicable for growing other state-of-the-art perovskite alloys, including triple-cation and mixed-halide perovskites.« less
Kim, Dong Hoe; Park, Jaehong; Li, Zhen; ...
2017-04-18
Organic-inorganic perovskites with intriguing optical and electrical properties have attracted significant research interests due to their excellent performance in optoelectronic devices. Recent efforts on preparing uniform and large-grain polycrystalline perovskite films have led to enhanced carrier lifetime up to several microseconds. However, the mobility and trap densities of polycrystalline perovskite films are still significantly behind their single-crystal counterparts. Here, a facile topotactic-oriented attachment (TOA) process to grow highly oriented perovskite films, featuring strong uniaxial-crystallographic texture, micrometer-grain morphology, high crystallinity, low trap density (≈4 x 10 14 cm -3), and unprecedented 9 GHz charge-carrier mobility (71 cm 2 V -1 smore » -1), is demonstrated. TOA-perovskite-based n-i-p planar solar cells show minimal discrepancies between stabilized efficiency (19.0%) and reverse-scan efficiency (19.7%). In conclusion, the TOA process is also applicable for growing other state-of-the-art perovskite alloys, including triple-cation and mixed-halide perovskites.« less
Development of an attached microalgal growth system for biofuel production.
Johnson, Michael B; Wen, Zhiyou
2010-01-01
Algal biofuel production has gained a renewed interest in recent years but is still not economically feasible due to several limitations related to algal culture. The objective of this study is to explore a novel attached culture system for growing the alga Chlorella sp. as biodiesel feedstock, with dairy manure wastewater being used as growth medium. Among supporting materials tested for algal attachment, polystyrene foam led to a firm attachment, high biomass yield (25.65 g/m(2), dry basis), and high fatty acid yield (2.31 g/m(2)). The biomass attached on the supporting material surface was harvested by scraping; the residual colonies left on the surface served as inoculum for regrowth. The algae regrowth on the colony-established surface resulted in a higher biomass yield than that from the initial growth on fresh surface due to the downtime saved for initial algal attachment. The 10-day regrowth culture resulted in a high biodiesel production potential with a fatty acid methyl esters yield of 2.59 g/m(2) and a productivity of 0.26 g/m(-2) day(-1). The attached algal culture also removed 61-79% total nitrogen and 62-93% total phosphorus from dairy manure wastewater, depending on different culture conditions. The biomass harvested from the attached growth system (through scraping) had a water content of 93.75%, similar to that harvested from suspended culture system (through centrifugation). Collectively, the attached algal culture system with polystyrene foam as a supporting material demonstrated a good performance in terms of biomass yield, biodiesel production potential, ease to harvest biomass, and physical robustness for reuse.
Iqbal, Asif; Arslan, Sinan; Okumus, Burak; Wilson, Timothy J.; Giraud, Gerard; Norman, David G.; Ha, Taekjip; Lilley, David M. J.
2008-01-01
We have found that the efficiency of fluorescence resonance energy transfer between Cy3 and Cy5 terminally attached to the 5′ ends of a DNA duplex is significantly affected by the relative orientation of the two fluorophores. The cyanine fluorophores are predominantly stacked on the ends of the helix in the manner of an additional base pair, and thus their relative orientation depends on the length of the helix. Observed fluorescence resonance energy transfer (FRET) efficiency depends on the length of the helix, as well as its helical periodicity. By changing the helical geometry from B form double-stranded DNA to A form hybrid RNA/DNA, a marked phase shift occurs in the modulation of FRET efficiency with helix length. Both curves are well explained by the standard geometry of B and A form helices. The observed modulation for both polymers is less than that calculated for a fully rigid attachment of the fluorophores. However, a model involving lateral mobility of the fluorophores on the ends of the helix explains the observed experimental data. This has been further modified to take account of a minor fraction of unstacked fluorophore observed by fluorescent lifetime measurements. Our data unequivocally establish that Förster transfer obeys the orientation dependence as expected for a dipole–dipole interaction. PMID:18676615
Library orientation methods: J. Hillis Miller Health Center Library program.
Eaton, E S
1972-01-01
Two orientation devices are described which are currently in use at the J. Hillis Miller Health Center Library. One is a taped tour which requires a portable recorder with earphones attached. Tapes are now available for nursing students, physical therapy students, and Health Center staff. The tour includes location information and description of the card catalog and certain basic index and abstract services. The second orientation device is a short instruction tape on the use of Index Medicus which is attached to the Index Medicus table. This is heard through a telephone apparatus. It is anticipated that the tape technique will be expanded to apply to other students and other library tools. It is also believed that this technique may be used in other libraries. Information about the supplies and equipment used is given as an addendum.
Preliminary development and validation of the Supervisee Attachment Strategies Scale (SASS).
Menefee, Deleene S; Day, Susan X; Lopez, Frederick G; McPherson, Robert H
2014-04-01
The influence of counselor trainees' adult attachment orientations in the context of supervision has the potential to inform both training and supervision practice. However, the pursuit of such research requires the availability of appropriate assessment tools. The present study describes the development and validation of the Supervisee Attachment Strategies Scale (SASS), a theory-based measure of counseling trainees' attachment orientations toward their clinical supervisors. Participants were recruited online through their training directors at Association of Psychology Postdoctoral and Internship Centers member programs. Data were nationally collected from 352 trainees representing programs in the United States and Canada. Exploratory factor analysis yielded 2 interpretable factors along the adult attachment dimensions of avoidance vs. engagement and rejection concern vs. security. These 2 factors accounted for 55.85% of the interitem variance in the rotated solution of the 22-item SASS scale. SASS subscale scores were negatively correlated with the supervisory working alliance and predicted greater endorsement of role conflict and role ambiguity in the current supervisory relationship. Higher avoidance (but not rejection concern) predicted diminished perceptions of satisfaction with the overall training experience. Findings from this study suggest that trainees who engaged in adaptive attachment strategies may be more likely to address conflict, negotiate additional explorative opportunities in training, and seek out their supervisors in times of uncertainty. (PsycINFO Database Record (c) 2014 APA, all rights reserved).
ERIC Educational Resources Information Center
Newcombe, Rhiannon; Reese, Elaine
2004-01-01
The present study examined the socialisation of children's narrative ability across the preschool period, exploring the association between children's and mothers' narrative style and children's attachment security. Fifty-six children and their mothers engaged in past event memory conversations about everyday shared past experiences when the…
ERIC Educational Resources Information Center
Taveggia, Thomas C.; Ziemba, Thomas
1978-01-01
Investigated overall central life interests and attachments to work of 1112 male and female employees of six Southern California manufacturing firms. Male employees have a slight tendency to be more work oriented in their overall central life interests than female employees. (Author)
McGee, Rob; Williams, Sheila; Howden-Chapman, Philippa; Martin, Jennifer; Kawachi, Ichiro
2006-02-01
We examined social participation in organized clubs and groups from childhood to adolescence in a sample of young people from Dunedin, New Zealand. Groups were broadly categorized as "sports" and "cultural/youth" groups. While the results indicated high levels of participation in childhood with a decline over the ensuing adolescent years, path analyses suggested strong continuities in participation over time. Both family "active-recreational" orientation (ARO) and "intellectual-cultural" orientation (ICO) predicted participation, and mediated the effects of disadvantage on participation. Participation was significantly related to adolescent attachment to parents, friends and school/workplace, as well as self-perceived strengths, after controlling for early family disadvantage and social support, peer attachment and literacy. The effect of participation in adolescence is to widen the "social convoy" to which young people are exposed as well as strengthening relationships within that convoy.
Sequence-Controlled Polymerization on Facially Amphiphilic Templates at Interfaces
2016-06-14
controlled chain growth polymerization. We will synthesize a ?- conjugated “parent” polymer by iterative exponential growth (IEG), attach cyclic olefin...template that is programmed to direct sequence- controlled chain growth polymerization. We will synthesize a ?- conjugated “parent” polymer by iterative...polymerization. We will synthesize a π- conjugated “parent” polymer by organometallic iterative exponential growth (IEG),2 attach cyclic olefin “daughter
Nature of inclined growth in thin-layer electrodeposition under uniform magnetic fields.
Soba, Alejandro; González, Graciela; Calivar, Lucas; Marshall, Guillermo
2012-11-01
Electrochemical deposition (ECD) in thin cells in a vertical position relative to gravity, subject to an external uniform magnetic field, yields a growth pattern formation with dense branched morphology with branches tilted in the direction of the magnetic force. We study the nature of the inclined growth through experiments and theory. Experiments in ECD, in the absence of magnetic forces, reveal that a branch grows by allowing fluid to penetrate its tip and to be ejected from the sides through a pair of symmetric vortices attached to the tip. The upper vortices zone defines an arch separating an inner zone ion depleted and an outer zone in a funnel-like form with a concentrated solution through which metal ions are carried into the tip. When a magnetic field is turned on, vortex symmetry is broken, one vortex becoming weaker than the other, inducing an inclination of the funnel. Consequently, particles entering the funnel give rise to branch growth tilted in the same direction. Theory predicts, in the absence of a magnetic force, funnel symmetry induced through symmetric vortices driven by electric and gravitational forces; when the magnetic force is on, it is composed with the pair of clockwise and counterclockwise vortices, reducing or amplifying one or the other. In turn, funnel tilting modifies particle trajectories, thus, growth orientation.
Dimensionality of Women's Career Orientation.
ERIC Educational Resources Information Center
Marshall, Sandra J.; Wijting, Jan P.
1982-01-01
Factor analysis of data from two samples identified nine indices of women's career orientation. Two factors accounted for significant variance common to the indices: career centeredness, which reflects the importance attached to a career relative to other life activities, and career commitment, which implies a commitment to lifetime employment.…
Oliveira, Paula; Costa, Maria Emilía
2009-11-01
This study examined associations between adult attachment dimensions, perceived health status and worrying (coping strategy with chronic pain), and explored whether worrying mediated observed relationships between attachment dimensions and health outcomes within a sample of 128 Portuguese female fibromyalgia patients. Physical health status was inversely correlated with dependence and worrying; mental health status was positively correlated with trust, and inversely related to attachment-related ambivalence, dependence and worrying. Finally, worrying mediated relationships between dependence and both physical and mental health status; moreover, worrying partially mediated the relationship between ambivalence and mental health status. Implications of the findings are discussed.
Effects of nerve cells and adhesion molecules on nerve conduit for peripheral nerve regeneration
Fiorellini, Joseph P.
2017-01-01
Background For peripheral nerve regeneration, recent attentions have been paid to the nerve conduits made by tissue-engineering technique. Three major elements of tissue-engineering are cells, molecules, and scaffolds. Methods In this study, the attachments of nerve cells, including Schwann cells, on the nerve conduit and the effects of both growth factor and adhesion molecule on these attachments were investigated. Results The attachment of rapidly-proliferating cells, C6 cells and HS683 cells, on nerve conduit was better than that of slowly-proliferating cells, PC12 cells and Schwann cells, however, the treatment of nerve growth factor improved the attachment of slowly-proliferating cells. In addition, the attachment of Schwann cells on nerve conduit coated with fibronectin was as good as that of Schwann cells treated with glial cell line-derived neurotrophic factor (GDNF). Conclusions Growth factor changes nerve cell morphology and affects cell cycle time. And nerve growth factor or fibronectin treatment is indispensable for Schwann cell to be used for implantation in artificial nerve conduits. PMID:29090249
Wiegand-Grefe, Silke; Bomba, Franziska; Tönnies, Sven; Bullinger, Monika; Plass, Angela
2016-01-01
Do Attachment Styles of Mentally Ill Parents Impact on the Health-related Quality of Life of their Children? Parents with a mental disorder often display a problematic attachment style which may impact on their children's health related quality of life (HrQoL). The current study cross-sectionally examines attachment styles (BEPE) in mentally ill parents with underage children (n = 62) and the effect of attachment on their children's HrQoL (KINDL-R). Results show that secure attachment is less represented in parents with a mental health condition than in a healthy reference group. Within the clinical sample, children of mentally ill parents with a secure attachment style exhibit a higher HrQoL than children of mentally ill parents with ambivalent or avoidant attachment styles. These findings indicate not only that problematic attachment styles frequently occur in families with a mentally ill parent, but also suggest that this negatively affects the children's HrQoL. Appropriate interventions should include attachment oriented concepts.
Fibre Optic Connections And Method For Using Same
Chan, Benson; Cohen, Mitchell S.; Fortier, Paul F.; Freitag, Ladd W.; Hall, Richard R.; Johnson, Glen W.; Lin, How Tzu; Sherman, John H.
2004-03-30
A package is described that couples a twelve channel wide fiber optic cable to a twelve channel Vertical Cavity Surface Emitting Laser (VCSEL) transmitter and a multiple channel Perpendicularly Aligned Integrated Die (PAID) receiver. The package allows for reduction in the height of the assembly package by vertically orienting certain dies parallel to the fiber optic cable and horizontally orienting certain other dies. The assembly allows the vertically oriented optoelectronic dies to be perpendicularly attached to the horizontally oriented laminate via a flexible circuit.
String stabilized ribbon growth a method for seeding same
Sachs, Emanuel M.
1987-08-25
This invention is a method of initiating or seeding the growth of a crystalline or polycrystalline ribbon by the String Stabilized Ribbon Growth Method. The method for seeding the crystal growth comprises contacting a melt surface with a seed and two strings used in edge stabilization. The wetted strings attach to the wetted seed as a result of the freezing of the liquid melt. Upon drawing the seed, which is attached to the strings, away from the melt surface a melt liquid meniscus, a seed junction, and a growth interface forms. Further pulling of the attached seed causes a crystal ribbon to grow at the growth interface. The boundaries of the growing ribbon are: at the top the seed junction, at the bottom the freezing boundary of the melt liquid meniscus, and at the edges frozen-in strings.
A Qualitative Exploration of the Use of Attachment Theory in Adult Psychological Therapy.
Burke, Eilish; Danquah, Adam; Berry, Katherine
2016-01-01
There is a growing interest into how attachment theory can inform psychotherapeutic practice with adults. This study aimed to explore how a group of therapists with an interest in attachment theory use it in their work with adult clients. A cross-sectional qualitative design was adopted. Sampling, data collection and analysis procedures were guided by grounded theory principles. Semi-structured telephone interviews were conducted with 12 therapists from a variety of training backgrounds. Data were coded and developed into thematic categories. Six primary themes were identified to describe how attachment theory influenced the clinical practice of the sample through the following: (i) complementing other therapeutic models; (ii) providing a framework to understand the development of clients' mental health problems; (iii) working with different attachment styles; (iv) thinking about the therapeutic relationship as an attachment relationship; (iv) influencing the different stages of the therapeutic process; and (vi) influencing clinical service design and delivery. It is concluded that attachment theory can play a significant role in influencing the practice of therapists and can be usefully adopted to complement therapeutic processes irrespective of the therapist's dominant clinical orientation. Further research is needed to explore the views of clinicians from different theoretical orientations and to investigate the security of the client-therapist attachment within the context of therapeutic change processes. Attachment theory may have implications for practice across a range of different types of therapy and may help therapists to bridge apparent differences between modality-specific formulation and techniques. Attachment theory can be used to understand the development of mental health problems. Therapists should assess and formulate clients' attachment styles, and these formulations should guide therapeutic approaches. Attachment theory provides a comprehensive framework for facilitating the therapist's attentiveness to relational issues and use of the therapeutic relationship as a fulcrum for change. The principles of attachment theory can be used to inform all stages of the therapeutic process, as well as the design and delivery of mental health services. Copyright © 2015 John Wiley & Sons, Ltd.
Polarimetry of Pinctada fucata nacre indicates myostracal layer interrupts nacre structure.
Metzler, Rebecca A; Jones, Joshua A; D'Addario, Anthony J; Galvez, Enrique J
2017-02-01
The inner layer of many bivalve and gastropod molluscs consists of iridescent nacre, a material that is structured like a brick wall with bricks consisting of crystalline aragonite and mortar of organic molecules. Myostracal layers formed during shell growth at the point of muscle attachment to the shell can be found interspersed within the nacre structure. Little has been done to examine the effect the myostracal layer has on subsequent nacre structure. Here we present data on the structure of the myostracal and nacre layers from a bivalve mollusc, Pinctada fucata . Scanning electron microscope imaging shows the myostracal layer consists of regular crystalline blocks. The nacre before the layer consists of tablets approximately 400 nm thick, while after the myostracal layer the tablets are approximately 500 nm thick. A new technique, imaging polarimetry, indicates that the aragonite crystals within the nacre following the myostracal layer have greater orientation uniformity than before the myostracal layer. The results presented here suggest a possible interaction between the myostracal layer and subsequent shell growth.
Shape-controlled narrow-gap SnTe nanostructures: From nanocubes to nanorods and nanowires
Guo, Shaojun; Andrew F. Fidler; He, Kai; ...
2015-11-06
In this study, the rational design and synthesis of narrow-gap colloidal semiconductor nanocrystals (NCs) is an important step toward the next generation of solution-processable photovoltaics, photodetectors, and thermoelectric devices. SnTe NCs are particularly attractive as a Pb-free alternative to NCs of narrow-gap lead chalcogenides. Previous synthetic efforts on SnTe NCs have focused on spherical nanoparticles. Here we report new strategies for synthesis of SnTe NCs with shapes tunable from highly monodisperse nanocubes, to nanorods (NRs) with variable aspect ratios, and finally to long, straight nanowires (NWs). Reaction at high temperature quickly forms thermodynamically favored nanocubes, but low temperatures lead tomore » elongated particles. Transmission electron microscopy studies of reaction products at various stages of the synthesis reveal that the growth and shape-focusing of monodisperse SnTe nanocubes likely involves interparticle ripening, while directional growth of NRs and NWs may be initiated by particle dimerization via oriented attachment.« less
Polarimetry of Pinctada fucata nacre indicates myostracal layer interrupts nacre structure
NASA Astrophysics Data System (ADS)
Metzler, Rebecca A.; Jones, Joshua A.; D'Addario, Anthony J.; Galvez, Enrique J.
2017-02-01
The inner layer of many bivalve and gastropod molluscs consists of iridescent nacre, a material that is structured like a brick wall with bricks consisting of crystalline aragonite and mortar of organic molecules. Myostracal layers formed during shell growth at the point of muscle attachment to the shell can be found interspersed within the nacre structure. Little has been done to examine the effect the myostracal layer has on subsequent nacre structure. Here we present data on the structure of the myostracal and nacre layers from a bivalve mollusc, Pinctada fucata. Scanning electron microscope imaging shows the myostracal layer consists of regular crystalline blocks. The nacre before the layer consists of tablets approximately 400 nm thick, while after the myostracal layer the tablets are approximately 500 nm thick. A new technique, imaging polarimetry, indicates that the aragonite crystals within the nacre following the myostracal layer have greater orientation uniformity than before the myostracal layer. The results presented here suggest a possible interaction between the myostracal layer and subsequent shell growth.
Turan, Bulent; Goldstein, Mary K.; Garber, Alan M.; Carstensen, Laura L.
2011-01-01
Objective At times caregivers make life-and-death decisions for loved ones. Yet very little is known about the factors that make caregivers more or less accurate as surrogate decision makers for their loved ones. Previous research suggests that in low stress situations, individuals with high attachment-related anxiety are attentive to their relationship partners’ wishes and concerns, but get overwhelmed by stressful situations. Individuals with high attachment-related avoidance are likely to avoid intimacy and stressful situations altogether. We hypothesized that both of these insecure attachment patterns limit surrogates’ ability to process distressing information and should therefore be associated with lower accuracy in the stressful task of predicting their loved ones’ end-of-life health care wishes. Methods Older patients visiting a medical clinic stated their preferences toward end-of-life health care in different health contexts and surrogate decision makers independently predicted those preferences. For comparison purposes, surrogates also predicted patients’ perceptions of everyday living conditions so that surrogates’ accuracy of their loved ones’ perceptions in non-stressful situations could be assessed. Results Surrogates high on either type of insecure attachment dimension were less accurate in predicting their loved ones’ end-of-life health care wishes. Interestingly, even though surrogates’ attachment-related anxiety was associated with lower accuracy of end-of-life health care wishes of patients, it was associated with higher accuracy in the non-stressful task of predicting their everyday living conditions. Conclusions Attachment orientation plays an important role in accuracy about loved ones’ end-of-life health care wishes. Interventions may target emotion regulation strategies associated with insecure attachment orientations. PMID:22081941
ERIC Educational Resources Information Center
Fischer, Natalie; Theis, Désirée
2014-01-01
School motivation and attachment typically decline after the transition to middle school. According to the stage-environment fit approach, extracurricular activities are supposed to promote motivation. However, research has shown that the effects depend on the quality of the activities, which usually is measured by assessing students' individual…
ERIC Educational Resources Information Center
Sarracino, Diego; Presaghi, Fabio; Degni, Silvia; Innamorati, Marco
2011-01-01
In early adolescence, attachment security reflects not only the quality of ongoing relationships with parents, but also how adolescents process social relationships with "others"--that is, their "social value orientation"--with possible implications for adolescents' risk-taking. In this study, a sample of Italian early…
Nuclear reactor support and seismic restraint with in-vessel core retention cooling features
DOE Office of Scientific and Technical Information (OSTI.GOV)
Edwards, Tyler A.; Edwards, Michael J.
A nuclear reactor including a lateral seismic restraint with a vertically oriented pin attached to the lower vessel head and a mating pin socket attached to the floor. Thermally insulating materials are disposed alongside the exterior surface of a lower portion of the reactor pressure vessel including at least the lower vessel head.
Wang, Yang; Zhang, Xiao-Jian; Chen, Yu-Qiao; Lu, Pin-Pin; Chen, Chao
2009-11-01
This study investigated the growth characteristics of iron bacteria on cast iron and relationship between suspended and attached iron bacteria. The steady-state growth of iron bacteria would need 12 d and iron bacteria level in effluents increased 1 lg. Hydraulics influence on iron bacteria level and detachment rate of steady-state attached iron bacteria was not significant. But it could affect the time of attached iron bacteria on cast-iron coupons reaching to steady state. When the chlorine residual was 0.3 mg/L, the iron bacteria growth could be controlled effectively and suspended and attached iron bacteria levels both decreased 1 lg. When the chlorine residual was more than 1.0 mg/L, it could not inactivate the iron bacteria of internal corrosion scale yet. There was little effect on inhibiting the iron bacteria growth that the chlorine residual was 0.05 mg/L in drinking water quality standard of China. The iron bacteria on coupons reached to steady state without disinfectant and then increased the chlorine residual to 1.25 mg/L, the attached iron bacteria level could decrease 2 lg to 3 lg. Under steady-state, the suspended iron bacteria levels were linearly dependent on the attached iron bacteria. The control of iron bacteria in drinking water distribution systems was advanced: maintaining the chlorine residual (0.3 mg/L), flushing the pipeline with high dosage disinfectant, adopting corrosion-resistant pipe materials and renovating the old pipe loop.
How do attachment dimensions affect bereavement adjustment? A mediation model of continuing bonds.
Yu, Wei; He, Li; Xu, Wei; Wang, Jianping; Prigerson, Holly G
2016-04-30
The current study aims to examine mechanisms underlying the impact of attachment dimensions on bereavement adjustment. Bereaved mainland Chinese participants (N=247) completed anonymous, retrospective, self-report surveys assessing attachment dimensions, continuing bonds (CB), grief symptoms and posttraumatic growth (PTG). Results demonstrated that attachment anxiety predicted grief symptoms via externalized CB and predicted PTG via internalized CB at the same time, whereas attachment avoidance positively predicted grief symptoms via externalized CB but negatively predicted PTG directly. Findings suggested that individuals with a high level of attachment anxiety could both suffer from grief and obtain posttraumatic growth after loss, but it depended on which kind of CB they used. By contrast, attachment avoidance was associated with a heightened risk of maladaptive bereavement adjustment. Future grief therapy may encourage the bereaved to establish CB with the deceased and gradually shift from externalized CB to internalized CB. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Jones, Jason D; Cassidy, Jude; Shaver, Phillip R
2015-02-01
For decades, attachment scholars have been investigating how parents' adult attachment orientations relate to the ways in which they parent. Traditionally, this research has been conducted by developmental and clinical psychologists who typically employ the Adult Attachment Interview (AAI) to measure adult attachment. However, dating back to the mid-1990s, social and personality psychologists have been investigating how self-reported adult attachment styles relate to various facets of parenting. The literature on self-reported attachment and parenting has received less attention than AAI research on the same topic and, to date, there is no comprehensive review of this literature. In this article, we review more than 60 studies of the links between self-reported attachment styles and parenting, integrate the findings to reach general conclusions, discuss unresolved questions, and suggest future directions. Finally, we discuss the potential benefits to the study of parenting of collaborations among researchers from the developmental and social attachment research traditions. © 2014 by the Society for Personality and Social Psychology, Inc.
Jones, Jason D.; Cassidy, Jude; Shaver, Phillip. R.
2014-01-01
For decades, attachment scholars have been investigating how parents’ adult attachment orientations relate to the ways in which they parent. Traditionally, this research has been conducted by developmental and clinical psychologists who typically employ the Adult Attachment Interview (AAI) to measure adult attachment. However, dating back to the mid-1990s, social and personality psychologists have been investigating how self-reported adult attachment styles relate to various facets of parenting. The literature on self-reported attachment and parenting has received less attention than AAI research on the same topic and, to date, there is no comprehensive review of this literature. In this article, we review over 60 studies of the links between self-reported attachment styles and parenting, integrate the findings to reach general conclusions, discuss unresolved questions, and suggest future directions. Finally, we discuss the potential benefits to the study of parenting of collaborations among researchers from the developmental and social attachment research traditions. PMID:25024278
Smith, Phillip N.; Gamble, Stephanie A.; Cort, Natalie A.; Ward, Erin A.; Conwell, Yeates; Talbot, Nancy L.
2012-01-01
Objective Women who experience both depression and a history of childhood sexual abuse are at substantially greater risk for suicide compared to those who experience depression alone. Though psychiatric diagnoses, such as Major Depression and Borderline Personality Disorder, are often considered in the assessment and management of suicide risk, understanding how enduring characteristics interact with contextual factors to result in suicide-related thoughts and behaviors may be more useful for identifying specific targets for intervention. Design The current study used cross-sectional survey methodology to examine the interaction of attachment orientation and acute social maladjustment as risk factors for death ideation in a sample of women with Major Depression and histories of childhood sexual abuse. Results Social maladjustment was associated with greater likelihood of endorsing death ideation. Avoidant and anxious attachment orientations moderated the social maladjustment and death ideation associations in some domains. Specifically, work-related social maladjustment was associated with greater odds of death ideation for those with higher levels of attachment avoidance. Parent-role related maladjustment was associated with greater odds of death ideation for those with lower levels of attachment anxiety. Conclusions Findings demonstrate strong associations between death ideation and acute social maladjustment, and suggest that death ideation may be specific to certain domains of adjustment for anxious and avoidant attachment styles. Implications for the conceptualization and treatment of patients who report death ideation are discussed. PMID:22125120
Sanchez, Sophie; Dupret, Vincent; Tafforeau, Paul; Trinajstic, Katherine M; Ryll, Bettina; Gouttenoire, Pierre-Jean; Wretman, Lovisa; Zylberberg, Louise; Peyrin, Françoise; Ahlberg, Per E
2013-01-01
Firm attachments binding muscles to skeleton are crucial mechanical components of the vertebrate body. These attachments (entheses) are complex three-dimensional structures, containing distinctive arrangements of cells and fibre systems embedded in the bone, which can be modified during ontogeny. Until recently it has only been possible to obtain 2D surface and thin section images of entheses, leaving their 3D histology largely unstudied except by extrapolation from 2D data. Entheses are frequently preserved in fossil bones, but sectioning is inappropriate for rare or unique fossil material. Here we present the first non-destructive 3D investigation, by propagation phase contrast synchrotron microtomography (PPC-SRµCT), of enthesis histology in extant and fossil vertebrates. We are able to identify entheses in the humerus of the salamander Desmognathus from the organization of bone-cell lacunae and extrinsic fibres. Statistical analysis of the lacunae differentiates types of attachments, and the orientation of the fibres, reflect the approximate alignment of the muscle. Similar histological structures, including ontogenetically related pattern changes, are perfectly preserved in two 380 million year old fossil vertebrates, the placoderm Compagopiscis croucheri and the sarcopterygian fish Eusthenopteron foordi. We are able to determine the position of entheses in fossil vertebrates, the approximate orientation of the attached muscles, and aspects of their ontogenetic histories, from PPC-SRµCT data. Sub-micron microtomography thus provides a powerful tool for studying the structure, development, evolution and palaeobiology of muscle attachments.
Orienteering: Growth Patterns in the United States.
ERIC Educational Resources Information Center
Jeffery, Charles F.
The history of orienteering in the United States includes both military and civilian interest, with the period of greatest growth between 1970 and 1980. To investigate growth patterns in orienteering, questionnaires were mailed to 42 civilian orienteering clubs and 286 universities supporting senior Reserve Office Training Corps (ROTC)…
Kim, Bo-Ram; Stifter, Cynthia A.; Philbrook, Lauren E.; Teti, Douglas M.
2014-01-01
The present study examines the influences of mothers’ emotional availability towards their infants during bedtime, infant attachment security, and interactions between bedtime parenting and attachment with infant temperamental negative affectivity, on infants’ emotion regulation strategy use at 12 and 18 months. Infants’ emotion regulation strategies were assessed during a frustration task that required infants to regulate their emotions in the absence of parental support. Whereas emotional availability was not directly related to infants’ emotion regulation strategies, infant attachment security had direct relations with infants’ orienting towards the environment and tension reduction behaviors. Both maternal emotional availability and security of the mother-infant attachment relationship interacted with infant temperamental negative affectivity to predict two strategies that were less adaptive in regulating frustration. PMID:24995668
Implications of kangaroo care for growth and development in preterm infants.
Dodd, Virginia L
2005-01-01
To review research on kangaroo care with implications for growth and development in preterm infants. Nursing, medical, and child development research literature was searched through PubMed through 2003 using the search terms kangaroo Care, skin-to-skin, growth/development, and premature infants. Randomized controlled trials, pretest-posttest designs, and other comparative studies of kangaroo care were reviewed. Reports exploring parent perspectives were examined for attachment and parent-infant interaction findings. Theory and research regarding growth in preterm infants were explored. Research on topics of kangaroo care, skin-to-skin contact, preterm infant growth, preterm infant weight gain, and failure to thrive was evaluated. Research on kangaroo care reports physiologic safety for preterm infants and increased attachment for parents. Attachment promotes nurturing behaviors that support growth and development. Weight gain as a benefit of kangaroo care remains in question. Kangaroo care is safe for preterm infants and may have important benefits for growth and development. Suggestions are made for future research on effects of KC on preterm infants.
Network growth models: A behavioural basis for attachment proportional to fitness
NASA Astrophysics Data System (ADS)
Bell, Michael; Perera, Supun; Piraveenan, Mahendrarajah; Bliemer, Michiel; Latty, Tanya; Reid, Chris
2017-02-01
Several growth models have been proposed in the literature for scale-free complex networks, with a range of fitness-based attachment models gaining prominence recently. However, the processes by which such fitness-based attachment behaviour can arise are less well understood, making it difficult to compare the relative merits of such models. This paper analyses an evolutionary mechanism that would give rise to a fitness-based attachment process. In particular, it is proven by analytical and numerical methods that in homogeneous networks, the minimisation of maximum exposure to node unfitness leads to attachment probabilities that are proportional to node fitness. This result is then extended to heterogeneous networks, with supply chain networks being used as an example.
ERIC Educational Resources Information Center
Popper, Sally D.; And Others
As part of a longitudinal study of postpartum adjustment and infant development, this study examined whether securely attached 12-month-old infants show greater object mastery motivation and social-object mastery motivation than do insecurely attached infants. Object mastery relates to infants' goal-directed behavior that is oriented toward…
ERIC Educational Resources Information Center
Zakalik, Robyn A.; Wei, Meifen
2006-01-01
This study examined perceived discrimination as both a mediator and moderator between adult attachment (anxiety and avoidance) and levels of depression in a gay male sample. Survey data were collected from 234 self-identified gay males through the Internet and in person through community resources across several states. Results from structural…
Lecannelier, Felipe; Silva, Jaime R; Hoffmann, Marianela; Melo, Rolando; Morales, Raquel
2014-01-01
The Chilean government commissioned a quasi-experimental study with a pre-/postintervention design that had two general aims: (a) to assess infants' psychoaffective developmental levels (pre-intervention phase) and (b) to evaluate whether an intervention based on the promotion of socioemotional development modifies the infant's psychoaffective development. Sixty-two institutionalized infants and their alternative caregivers were evaluated at a pre-intervention stage. An intervention then took place, with the caregivers trained according to an "attachment sensitivity manual." Results showed normal ranges of psychomotor development (64% normal, 9% delayed) and a very high frequency of attachment insecurity, as compared to the normative population (53%).The intervention significantly improved social orientation and object orientation as well as activity and reactivity levels. We conclude that although institutionalized infants in Chile do not exhibit high levels of atypical attachment, socioemotional deterioration may lead to vulnerability in present and future development. Finally, the scope of this study affected public policies regarding children, initiating a change to a foster family system and a variety of modifications in the strategies for adopting institutionalized infants. © 2014 Michigan Association for Infant Mental Health.
Oriented molecular sieve membranes by heteroepitaxial growth.
Jeong, Hae-Kwon; Krohn, John; Sujaoti, Khristina; Tsapatsis, Michael
2002-11-06
Heteroepitaxial growth of titanosilicates (ETS-10 and ETS-4) is reported. Using this heteroepitaxial growth, oriented ETS-10/-4 membranes have been fabricated, demonstrating a novel way to achieve preferred orientation of molecular sieve films.
Kelley, Melissa M; Chan, Keith T
2012-03-01
Research has examined the relationship of styles of attachment to others and meaning with grief and the stress-related growth process. Less has been written on styles of attachment to God and patterns of religious coping and how these constructs may impact adjustment in persons dealing with loss. This study examines the roles of attachment to God, meaning, and religious coping as mediators in the grief experience for a sample of 93 individuals who experienced a significant death in the prior year. Results suggest that a more secure style of attachment to God was directly and indirectly associated with lower depression and grief and increased stress-related growth for this sample. Meaning, defined as a sense of purpose and coherence, also emerged as an important construct in this process. Overall goodness-of fit statistics were examined for competing models using structural equation modeling. Secure attachment to God, meaning, and positive religious coping were found to have significant direct and indirect effects on grief and stress-related growth. For some individuals, attachment to God may be an important construct in the experience of meaning following a significant death and may have tremendous potential in its direct and indirect effects on overall outcomes.
Adult Attachment, Social Adjustment, and Well-Being in Drug-Addicted Inpatients.
Delvecchio, Elisa; Di Riso, Daniela; Lis, Adriana; Salcuni, Silvia
2016-04-01
In recent years, attachment studies have gathered overwhelming evidence for a relation between insecure attachment and drug addiction. The existing literature predominantly addresses attachment styles and little attention is given to attachment-pattern-oriented studies. The current study explored how attachment, social adjustment, and well-being interact in 40 (28 men, 12 women; ages 20-52 years, M = 32.3, SD = 9.4) inpatients with drug addiction. The Adult Attachment Projective Picture System (AAP), the Social Adjustment Scale-Self-report (SAS-SR), and the General Health Questionnaire-28 (GHQ-28) were administered. Descriptive statistics were computed as well as differences between patterns of attachment in all variables were measured. None of the inpatients showed a secure attachment pattern: 7 scored as dismissing (18%), 5 preoccupied (12%) and 28 unresolved (70%). AAP stories were mainly connected with themes of danger, lack of protection, and helplessness. Inpatients classified as unresolved reported significantly higher maladjustment on the SAS-SR and GHQ-28 than those with resolved attachment patterns. Implications for clinicians and researchers are presented. © The Author(s) 2016.
Cao, Xiancai; Madore, Kevin P; Wang, Dahua; Schacter, Daniel L
2018-09-01
Attachment theories and studies have shown that Internal Working Models (IWMs) can impact autobiographical memory and future-oriented information processing relevant to close relationships. According to the constructive episodic simulation hypothesis (CESH), both remembering the past and imagining the future rely on episodic memory. We hypothesised that one way IWMs may bridge past experiences and future adaptations is via episodic memory. The present study investigated the association between attachment and episodic specificity in attachment-relevant and attachment-irrelevant memory and imagination among young and older adults. We measured the attachment style of 37 young adults and 40 older adults, and then asked them to remember or imagine attachment-relevant and attachment-irrelevant events. Participants' narratives were coded for internal details (i.e., episodic) and external details (e.g., semantic, repetitions). The results showed that across age group, secure individuals generated more internal details and fewer external details in attachment-relevant tasks compared to attachment-irrelevant tasks; these differences were not observed in insecure individuals. These findings support the CESH and provide a new perspective to understand the function of IWMs.
Pavlovčič, Urban; Diaci, Janez; Možina, Janez; Jezeršek, Matija
2013-09-26
Knowing the orientation of the head is important in many fields, including medicine. Many methods and measuring systems exist, but usually they use different markers or sensors attached to the subject's head for head orientation determination. In certain applications these attachments may represent a burden or a distraction to the subject under study which may have an unfavourable impact on the measurement. We propose a non-contact optical method for head-to-trunk orientation measurement that does not require any attachments to the subject under study. An innovative handheld 3D apparatus has been developed for non-invasive and fast 3D shape measurements. It is based on the triangulation principle in combination with fringe projection. The shape of the subject's upper trunk and head is reconstructed from a single image using the Fourier transform profilometry method. Two shape measurements are required to determine the head-to-trunk orientation angles: one in the reference (neutral) position and the other one in the position of interest. The algorithm for the head-to-trunk orientation angle extraction is based on the separate alignment of the shape of the subject's upper trunk and head against the corresponding shape in the reference pose. Single factor analysis of variance (ANOVA) was used for statistical characterisation of the method precision. The method and the 3D apparatus were verified in-vitro using a mannequin and a reference orientation tracker. The uncertainty of the calculated orientation was 2°. During the in-vivo test with a human subject diagnosed with cervical dystonia (aged 60), the repeatability of the measurements was 3°. In-vitro and in-vivo comparison was done on the basis of an experiment with the mannequin and a healthy male (aged 29). These results show that only the difference between flexion/extension measured angles was statistically significant. The differences between means were less than 1° for all ranges. The new non-contact method enables the compensation of the movement of the measuring instrument or the subject's body as a whole, is non-invasive, requires little additional equipment and causes little stress for the subject and operator. We find that it is appropriate for measurements of the head orientation with respect to the trunk for the characterization of the cervical dystonia.
Mechanisms of complex network growth: Synthesis of the preferential attachment and fitness models
NASA Astrophysics Data System (ADS)
Golosovsky, Michael
2018-06-01
We analyze growth mechanisms of complex networks and focus on their validation by measurements. To this end we consider the equation Δ K =A (t ) (K +K0) Δ t , where K is the node's degree, Δ K is its increment, A (t ) is the aging constant, and K0 is the initial attractivity. This equation has been commonly used to validate the preferential attachment mechanism. We show that this equation is undiscriminating and holds for the fitness model [Caldarelli et al., Phys. Rev. Lett. 89, 258702 (2002), 10.1103/PhysRevLett.89.258702] as well. In other words, accepted method of the validation of the microscopic mechanism of network growth does not discriminate between "rich-gets-richer" and "good-gets-richer" scenarios. This means that the growth mechanism of many natural complex networks can be based on the fitness model rather than on the preferential attachment, as it was believed so far. The fitness model yields the long-sought explanation for the initial attractivity K0, an elusive parameter which was left unexplained within the framework of the preferential attachment model. We show that the initial attractivity is determined by the width of the fitness distribution. We also present the network growth model based on recursive search with memory and show that this model contains both the preferential attachment and the fitness models as extreme cases.
How Escherichia coli lands and forms cell clusters on a surface: a new role of surface topography
Gu, Huan; Chen, Aaron; Song, Xinran; Brasch, Megan E.; Henderson, James H.; Ren, Dacheng
2016-01-01
Bacterial response to surface topography during biofilm formation was studied using 5 μm tall line patterns of poly (dimethylsiloxane) (PDMS). Escherichia coli cells attached on top of protruding line patterns were found to align more perpendicularly to the orientation of line patterns when the pattern narrowed. Consistently, cell cluster formation per unit area on 5 μm wide line patterns was reduced by 14-fold compared to flat PDMS. Contrasting the reduced colony formation, cells attached on narrow patterns were longer and had higher transcriptional activities, suggesting that such unfavorable topography may present a stress to attached cells. Results of mutant studies indicate that flagellar motility is involved in the observed preference in cell orientation on narrow patterns, which was corroborated by the changes in cell rotation pattern before settling on different surface topographies. These findings led to a set of new design principles for creating antifouling topographies, which was validated using 10 μm tall hexagonal patterns. PMID:27412365
Yu, Mingzhe; Draskovic, Thomas I; Wu, Yiying
2014-06-02
The delafossite CuGaO2 is an important p-type transparent conducting oxide for both fundamental science and industrial applications. An emerging application is for p-type dye-sensitized solar cells. Obtaining delafossite CuGaO2 nanoparticles is challenging but desirable for efficient dye loading. In this work, the phase formation and crystal growth mechanism of delafossite CuGaO2 under low-temperature (<250 °C) hydrothermal conditions are systematically studied. The stabilization of Cu(I) cations in aqueous solution and the controlling of the hydrolysis of Ga(III) species are two crucial factors that determine the phase formation. The oriented attachment (OA) growth is proposed as the crystal growth mechanism to explain the formation of large CuGaO2 nanoplates. Importantly, by suppressing this OA process, delafossite CuGaO2 nanoparticles that are 20 nm in size were successfully synthesized for the first time. Moreover, considering the structural and chemical similarities between the Cu-based delafossite series compounds, the understanding of the hydrothermal chemistry and crystallization mechanism of CuGaO2 should also benefit syntheses of other similar delafossites such as CuAlO2 and CuScO2.
Kim, Bo-Ram; Stifter, Cynthia A; Philbrook, Lauren E; Teti, Douglas M
2014-11-01
The present study examines the influences of mothers' emotional availability toward their infants during bedtime, infant attachment security, and interactions between bedtime parenting and attachment with infant temperamental negative affectivity, on infants' emotion regulation strategy use at 12 and 18 months. Infants' emotion regulation strategies were assessed during a frustration task that required infants to regulate their emotions in the absence of parental support. Whereas emotional availability was not directly related to infants' emotion regulation strategies, infant attachment security had direct relations with infants' orienting toward the environment and tension reduction behaviors. Both maternal emotional availability and security of the mother-infant attachment relationship interacted with infant temperamental negative affectivity to predict two strategies that were less adaptive in regulating frustration. Copyright © 2014 Elsevier Inc. All rights reserved.
Drag Enhancement of Microbial Slime Films on Rotating Discs.
1981-03-27
barnacle and algal growth , had also occurred (7). Laboratory culture eliminated these contaminants. The bacteria were grown in artificial seawater (Instant...attachment and growth under flow conditions , using an aquarium power filter pump (12). Films grown in this manner were sufficiently adherent to plastic...the large and easily visible organisms, such as barnacles, bryozoa, and tubeworms do not prevent attachment and growth of micro-organisms, which may
A stabilized headless measles virus attachment protein stalk efficiently triggers membrane fusion.
Brindley, Melinda A; Suter, Rolf; Schestak, Isabel; Kiss, Gabriella; Wright, Elizabeth R; Plemper, Richard K
2013-11-01
Paramyxovirus attachment and fusion (F) envelope glycoprotein complexes mediate membrane fusion required for viral entry. The measles virus (MeV) attachment (H) protein stalk domain is thought to directly engage F for fusion promotion. However, past attempts to generate truncated, fusion-triggering-competent H-stem constructs remained fruitless. In this study, we addressed the problem by testing the hypothesis that truncated MeV H stalks may require stabilizing oligomerization tags to maintain intracellular transport competence and F-triggering activity. We engineered H-stems of different lengths with added 4-helix bundle tetramerization domains and demonstrate restored cell surface expression, efficient interaction with F, and fusion promotion activity of these constructs. The stability of the 4-helix bundle tags and the relative orientations of the helical wheels of H-stems and oligomerization tags govern the kinetics of fusion promotion, revealing a balance between H stalk conformational stability and F-triggering activity. Recombinant MeV particles expressing a bioactive H-stem construct in the place of full-length H are viable, albeit severely growth impaired. Overall, we demonstrate that the MeV H stalk represents the effector domain for MeV F triggering. Fusion promotion appears linked to the conformational flexibility of the stalk, which must be tightly regulated in viral particles to ensure efficient virus entry. While the pathways toward assembly of functional fusion complexes may differ among diverse members of the paramyxovirus family, central elements of the triggering machinery emerge as highly conserved.
Hart, Joshua; Hung, Jacqueline A; Glick, Peter; Dinero, Rachel E
2012-11-01
The authors present an integrative account of how attachment insecurities relate to sexism. Two studies showed that attachment avoidance predisposes men to endorse hostile but to reject benevolent sexism (BS), whereas attachment anxiety predisposes men toward ambivalent (both hostile and benevolent) sexism. The authors also tested predicted mediators, finding that men's social dominance orientation (a competitive intergroup ideology) mediated the avoidance to hostile sexism link. In addition, romanticism (an idealized interpersonal ideology) mediated attachment insecurity to BS links: (a) Avoidant men tended to reject romanticism (i.e., were cynical about romance) and, in turn, were likely to reject BS, whereas (b) anxious men tended to endorse romanticism (i.e., were idealistic about romance) and, in turn, likely to endorse BS. The authors conclude that men's sexism stems in part from dispositional attachment working models, both directly and through the interpersonal and intergroup ideologies they generate.
Plasma-electric field controlled growth of oriented graphene for energy storage applications
NASA Astrophysics Data System (ADS)
Ghosh, Subrata; Polaki, S. R.; Kamruddin, M.; Jeong, Sang Mun; (Ken Ostrikov, Kostya
2018-04-01
It is well known that graphene grows as flat sheets aligned with the growth substrate. Oriented graphene structures typically normal to the substrate have recently attracted major attention. Most often, the normal orientation is achieved in a plasma-assisted growth and is believed to be due to the plasma-induced in-built electric field, which is usually oriented normal to the substrate. This work focuses on the effect of an in-built electric field on the growth direction, morphology, interconnectedness, structural properties and also the supercapacitor performance of various configurations of graphene structures and reveals the unique dependence of these features on the electric field orientation. It is shown that tilting of growth substrates from parallel to the normal direction with respect to the direction of in-built plasma electric field leads to the morphological transitions from horizontal graphene layers, to oriented individual graphene sheets and then interconnected 3D networks of oriented graphene sheets. The revealed transition of the growth orientation leads to a change in structural properties, wetting nature, types of defect in graphitic structures and also affects their charge storage capacity when used as supercapacitor electrodes. This simple and versatile approach opens new opportunities for the production of potentially large batches of differently oriented and structured graphene sheets in one production run.
Anatomy and biomechanics of gluteus maximus and the thoracolumbar fascia at the sacroiliac joint.
Barker, P J; Hapuarachchi, K S; Ross, J A; Sambaiew, E; Ranger, T A; Briggs, C A
2014-03-01
Biomechanical models predict that recruitment of gluteus maximus (GMax) will exert a compressive force across the sacroiliac joint (SIJ), yet this muscle requires morphologic assessment. The aims of this study were to document GMax's proximal attachments and assess their capacity to generate forces including compressive force at the SIJ. In 11 embalmed cadaver limbs, attachments of GMax crossing the SIJ were dissected and their fascicle orientation, length and attachment volume documented. The physiological cross-sectional area (PCSA) of each attachment was calculated along with its estimated maximum force at the SIJ and lumbar spine. GMax fascicles originated from the gluteus medius fascia, ilium, thoracolumbar fascia, erector spinae aponeurosis, sacrum, coccyx, dorsal sacroiliac and sacrotuberous ligaments in all specimens. Their mean fascicle orientation ranged from 32 to 45° below horizontal and mean length from 11 to 18 cm. The mean total PCSA of GMax was 26 cm(2) (range 16-36), of which 70% crossed the SIJ. The average maximum force predicted to be generated by GMax's total attachments crossing each SIJ was 891 N (range 572-1,215), of which 70% (702 N: range 450-1,009) could act perpendicular to the plane of the SIJ. The capacity of GMax to generate an extensor moment at lower lumbar segments was estimated at 4 Nm (range 2-9.5). GMax may generate compressive forces at the SIJ through its bony and fibrous attachments. These may assist effective load transfer between lower limbs and trunk. Copyright © 2013 Wiley Periodicals, Inc.
Nicholson, David A; Rutledge, Gregory C
2016-12-28
Non-equilibrium molecular dynamics is used to study crystal nucleation of n-eicosane under planar shear and, for the first time, uniaxial extension. A method of analysis based on the mean first-passage time is applied to the simulation results in order to determine the effect of the applied flow field type and strain rate on the steady-state nucleation rate and a characteristic growth rate, as well as the effects on kinetic parameters associated with nucleation: the free energy barrier, critical nucleus size, and monomer attachment pre-factor. The onset of flow-enhanced nucleation (FEN) occurs at a smaller critical strain rate in extension as compared to shear. For strain rates larger than the critical rate, a rapid increase in the nucleation rate is accompanied by decreases in the free energy barrier and critical nucleus size, as well as an increase in chain extension. These observations accord with a mechanism in which FEN is caused by an increase in the driving force for crystallization due to flow-induced entropy reduction. At high applied strain rates, the free energy barrier, critical nucleus size, and degree of stretching saturate, while the monomer attachment pre-factor and degree of orientational order increase steadily. This trend is indicative of a significant diffusive contribution to the nucleation rate under intense flows that is correlated with the degree of global orientational order in a nucleating system. Both flow fields give similar results for all kinetic quantities with respect to the reduced strain rate, which we define as the ratio of the applied strain rate to the critical rate. The characteristic growth rate increases with increasing strain rate, and shows a correspondence with the nucleation rate that does not depend on the type of flow field applied. Additionally, a structural analysis of the crystalline clusters indicates that the flow field suppresses the compaction and crystalline ordering of clusters, leading to the formation of large articulated clusters under strong flow fields, and compact well-ordered clusters under weak flow fields.
Hogan, Nancy; Schmidt, Lee; Coolican, Maggie
2014-09-01
Donated tissues can save lives of critically burned patients and those needing a heart valve replacement. Tissues enhance the lives of a million recipients annually through transplants of corneas, bones, tendons, and vein grafts. Unfortunately, the need for some tissues exceeds their availability. The goal of the quantitative component of this mixed methods study was to identify the grief, posttraumatic stress, personal growth, and ongoing attachment response of tissue donors' family members during a 2-year period. Simultaneous mixed methods design. The sample for this study consisted of 52 tissue donors' family members, mostly widows (83%). Data were collected for 2 years to test changes in grief, posttraumatic stress, panic behavior, personal growth, and ongoing attachment. The bereaved participants experienced significantly fewer grief reactions, less posttraumatic stress, and greater personal growth. There was no significant difference in the ongoing attachment to their deceased loved ones. The results of this study may reinforce the positive meaning that tissue donors' family members can find in tissue donation. Findings also demonstrate that the bereavement process corroborates contemporary bereavement and attachment theories. Health professionals are encouraged to seek donations with less worry that tissue donors' family members will experience adverse outcomes during bereavement.
Scharf, Miri; Mayseless, Ofra
2009-03-01
Elementary school teachers identified characteristics in 4 major socioemotional domains associated with children's social leadership: self-perception, social anxiety, attachment orientation with peers, and interpersonal goals and skills in close friendships. Participants were 260 4th- and 5th-grade students (126 boys, 134 girls) from 10 classes in a school in northern Israel. Social leadership skills were associated with positive self-perceptions in various domains, low social anxiety, secure orientation to peers, higher levels of relationship-maintenance goal, lower levels of revenge goal in close friendships, and-unexpectedly-lower levels of accommodation as a strategy to solve conflicts with a friend. Positive self-concept and attachment security were indirectly associated with leadership qualities through their significant association with prosocial orientation skills. The authors discuss these findings as reflecting an internalization of positive model of self and positive model of others in children who exhibit social leadership qualities. The authors also discuss implications of these qualities for school and class ecology, as well as the importance of culture.
Infant Nutrition and 12 and 18 Months Secure Base Behavior: An Exploratory Study
ERIC Educational Resources Information Center
Wachs, Theodore D.; Posada, German; Carbonell, Olga A.; Creed-Kanashiro, Hillary; Gurkas, Pinar
2011-01-01
A notable omission in studies of developmental links to early nutritional deficiencies is infant attachment. In those few studies investigating associations between infant nutrition and attachment, nutrition was defined solely by physical growth, and infants had moderate-severe growth retardation. In this study, we utilized multiple markers of…
Mohd-Sahib, Ainur-Assyakirin; Lim, Jun-Wei; Lam, Man-Kee; Uemura, Yoshimitsu; Isa, Mohamed Hasnain; Ho, Chii-Dong; Kutty, Shamsul Rahman Mohamed; Wong, Chung-Yiin; Rosli, Siti-Suhailah
2017-09-01
The potential to grow attached microalgae Chlorella vulgaris in fluidized bed bioreactor was materialized in this study, targeting to ease the harvesting process prior to biodiesel production. The proposed thermodynamic mechanism and physical property assessment of various support materials verified polyurethane to be suitable material favouring the spontaneous adhesion by microalgae cells. The 1-L bioreactor packed with only 2.4% (v/v) of 1.00-mL polyurethane foam cubes could achieve the highest attached growth microalgae biomass and lipid weights of 812±122 and 376±37mg, respectively, in comparison with other cube sizes. The maturity of attached growth microalgae biomass for harvesting could also be determined from the growth trend of suspended microalgae biomass. Analysis of FAME composition revealed that the harvested microalgae biomass was dominated by C16-C18 (>60%) and mixture of saturated and mono-unsaturated fatty acids (>65%), satiating the biodiesel standard with adequate cold flow property and oxidative stability. Copyright © 2017 Elsevier Ltd. All rights reserved.
Effects of substrate orientation on the growth of InSb nanostructures by molecular beam epitaxy
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chou, C. Y.; Torfi, A.; Pei, C.
2016-05-09
In this work, the effects of substrate orientation on InSb quantum structure growth by molecular beam epitaxy (MBE) are presented. Motivated by the observation that (411) evolves naturally as a stable facet during MBE crystal growth, comparison studies have been carried out to investigate the effects of the crystal orientation of the underlying GaSb substrate on the growth of InSb by MBE. By depositing InSb on a number of different substrate orientations, namely: (100), (311), (411), and (511), a higher nanostructure density was observed on the (411) surface compared with the other orientations. This result suggests that the (411) orientationmore » presents a superior surface in MBE growth to develop a super-flat GaSb buffer surface, naturally favorable for nanostructure growth.« less
Tauchman, Eric C; Boehm, Frederick J; DeLuca, Jennifer G
2015-12-01
During mitosis, duplicated sister chromatids attach to microtubules emanating from opposing sides of the bipolar spindle through large protein complexes called kinetochores. In the absence of stable kinetochore-microtubule attachments, a cell surveillance mechanism known as the spindle assembly checkpoint (SAC) produces an inhibitory signal that prevents anaphase onset. Precisely how the inhibitory SAC signal is extinguished in response to microtubule attachment remains unresolved. To address this, we induced formation of hyper-stable kinetochore-microtubule attachments in human cells using a non-phosphorylatable version of the protein Hec1, a core component of the attachment machinery. We find that stable attachments are sufficient to silence the SAC in the absence of sister kinetochore bi-orientation and strikingly in the absence of detectable microtubule pulling forces or tension. Furthermore, we find that SAC satisfaction occurs despite the absence of large changes in intra-kinetochore distance, suggesting that substantial kinetochore stretching is not required for quenching the SAC signal.
Tauchman, Eric C.; Boehm, Frederick J.; DeLuca, Jennifer G.
2015-01-01
During mitosis, duplicated sister chromatids attach to microtubules emanating from opposing sides of the bipolar spindle through large protein complexes called kinetochores. In the absence of stable kinetochore–microtubule attachments, a cell surveillance mechanism known as the spindle assembly checkpoint (SAC) produces an inhibitory signal that prevents anaphase onset. Precisely how the inhibitory SAC signal is extinguished in response to microtubule attachment remains unresolved. To address this, we induced formation of hyper-stable kinetochore–microtubule attachments in human cells using a non-phosphorylatable version of the protein Hec1, a core component of the attachment machinery. We find that stable attachments are sufficient to silence the SAC in the absence of sister kinetochore bi-orientation and strikingly in the absence of detectable microtubule pulling forces or tension. Furthermore, we find that SAC satisfaction occurs despite the absence of large changes in intra-kinetochore distance, suggesting that substantial kinetochore stretching is not required for quenching the SAC signal. PMID:26620470
USDA-ARS?s Scientific Manuscript database
Studies in Argentina and Chile during 2010-11 evaluated a new trap (Ajar) for monitoring the oriental fruit moth, Grapholita molesta (Busck). The Ajar trap was delta-shaped with a jar filled with a terpinyl acetate plus brown sugar bait attached to the bottom center of the trap. The screened lid of ...
Graphene Growth on Low Carbon Solubility Metals
NASA Astrophysics Data System (ADS)
Wofford, Joseph Monroe
Advances in synthesis are imperative if graphene is to fulfill its scientific and technological potential. Single crystal graphene of is currently available only in the small flakes generated by mechanical exfoliation. Layers of larger size may be grown either by the thermal decomposition of SiC or by chemical vapor deposition on metals. However, as they are currently implemented, these methods yield graphene films of inferior quality. Thus the requirement for wafer-scale, high-quality graphene films remains unmet. This dissertation addresses this issue by examining graphene growth on metal surfaces. Through a survey of the fundamental underlying processes, it provides guidance for improving the quality of the resulting graphene films. Graphene was grown on Cu(100), Cu(111), and Au(111) by physical vapor deposition of elemental C. The nucleation and growth behaviors of graphene were evaluated by low-energy electron microscopy. Graphene tends to nucleate heterogeneously at surface imperfections although it also does so homogeneously on Cu(111) and Au(111). Graphene growing on Cu(100) is governed by the attachment kinetics of C at the propagating crystal front. The resulting angularly dependent growth rate sculpts individual crystals into elongated lobes. In contrast, graphene growth on both Cu(111) and Au(111) is surface diffusion limited. This yields ramified, dendritic graphene islands. Graphene films grown on Cu(100) contain significant rotational disorder. This disorder is partially attributable to the symmetry mismatch between film and substrate. The common symmetry between graphene and Cu(111) contributes to a significant reduction in disorder in films grown on this surface. Most graphene domains occupy a ˜6º arc of orientations. On Au(111) the vast majority of graphene domains are locked into alignment with the substrate surface. The extraordinary extent of their orientational homogeneity is such that the resulting graphene film is a quasi-single crystal. The findings presented illustrate how metal species and crystal symmetry influence the structural properties of monolayer graphene. The selection of an optimal substrate for graphene growth can significantly reduce crystalline disorder in the resulting film.
Heinze, Justin; Miller, Alison L.; Zimmerman, Marc A.
2015-01-01
Purpose Forming secure friendship attachments during adolescence are important for mental health; few, however, have specifically examined the ways in which the transitions in attachment during adolescence may influence future mental health outcomes among African-Americans. Method The current study examines how transitions in attachment in adolescence predicted changes in depression symptoms from late adolescents through adulthood in an African-American sample of adolescents. We used growth curve modeling to examine the association between transitions in friendship attachment and changes in depression symptoms in adulthood. Results At age 16, 346 (64.0%) reported secure attachment with 195 (36.0%) reporting either avoidant or resistant attachment. At age 17, 340 (62.9%) reported secure attachment and 201 (37.2%) reported avoidant or resistant attachment. The largest percentage of participants (46.2%) reported stable-secure attachment across the two time points. Results of the growth model indicated that adolescents who reported a stable-secure attachment style had lower levels of depression symptoms during adulthood than those individuals who transitioned from secure-to-insecure, from insecure-to-secure, or were in the stable-insecure group. Interestingly enough, individuals in both of the attachment transition groups had a faster declining rate of depression symptoms over time compared to the two stability groups. Conclusion Data support existing research showing an association between transitions in attachment during adolescence and depression through adulthood. Further these study findings suggest there may be protective features associated with transitioning between attachment styles during adolescence on later depression, compared to African-American’s who remain stable in their attachment style. PMID:26903426
Space Station accommodation of attached payloads
NASA Technical Reports Server (NTRS)
Browning, Ronald K.; Gervin, Janette C.
1987-01-01
The Attached Payload Accommodation Equipment (APAE), which provides the structure to attach payloads to the Space Station truss assembly, to access Space Station resources, and to orient payloads relative to specified targets, is described. The main subelements of the APAE include a station interface adapter, payload interface adapter, subsystem support module, contamination monitoring system, payload pointing system, and attitude determination system. These components can be combined to provide accommodations for small single payloads, small multiple payloads, large self-supported payloads, carrier-mounted payloads, and articulated payloads. The discussion also covers the power, thermal, and data/communications subsystems and operations.
Karakurt, Gunnur; Silver, Kristin E
2014-01-01
The aim of this paper is to understand the effects of childhood sexual abuse on a survivor's later life. For understanding and treating the emotional distress and interpersonal problems resulting from childhood sexual abuse, attachment theory provides a valuable framework. When this framework is combined with family systems theory, it can help therapists understand the family context where sexual abuse occurs and how this affects health and functioning throughout the lifespan. Case examples of female adult sexual abuse survivors are also explored, with insight from the intersection of systems and attachment theories.
The Politics of Attachment: Lines of Flight with Bowlby, Deleuze and Guattari.
Duschinsky, Robbie; Greco, Monica; Solomon, Judith
2015-12-01
Research on attachment is widely regarded in sociology and feminist scholarship as politically conservative - oriented by a concern to police families, pathologize mothers and emphasize psychological at the expense of socio-economic factors. These critiques have presented attachment theory as constructing biological imperatives to naturalize contingent, social demands. We propose that a more effective critique of the politically conservative uses of attachment theory is offered by engaging with the 'attachment system' at the level of ontology. In developing this argument we draw on Deleuze and Guattari, making use of the common language of ethology which links their ideas to that of attachment theory. The attachment system can and has been reified into an image of the infant returning to their caregiver as an image of familial sufficiency. This has offered ammunition for discourses and institutions which isolate women from health, social and political resources. Yet Deleuze and Guattari can help attachment theory and research to be recognized as a powerful ally for progressive politics, for reflection on the movement of human individuation, and for arguing for the meaningful resourcing of those who care for someone else.
Polarimetry of Pinctada fucata nacre indicates myostracal layer interrupts nacre structure
Jones, Joshua A.; D'Addario, Anthony J.; Galvez, Enrique J.
2017-01-01
The inner layer of many bivalve and gastropod molluscs consists of iridescent nacre, a material that is structured like a brick wall with bricks consisting of crystalline aragonite and mortar of organic molecules. Myostracal layers formed during shell growth at the point of muscle attachment to the shell can be found interspersed within the nacre structure. Little has been done to examine the effect the myostracal layer has on subsequent nacre structure. Here we present data on the structure of the myostracal and nacre layers from a bivalve mollusc, Pinctada fucata. Scanning electron microscope imaging shows the myostracal layer consists of regular crystalline blocks. The nacre before the layer consists of tablets approximately 400 nm thick, while after the myostracal layer the tablets are approximately 500 nm thick. A new technique, imaging polarimetry, indicates that the aragonite crystals within the nacre following the myostracal layer have greater orientation uniformity than before the myostracal layer. The results presented here suggest a possible interaction between the myostracal layer and subsequent shell growth. PMID:28386442
Lee, Hyunsoo; Lee, Han-Bo-Ram; Kwon, Sangku; Salmeron, Miquel; Park, Jeong Young
2015-04-28
We report on the physical and chemical properties of atomic steps on the surface of highly oriented pyrolytic graphite (HOPG) investigated using atomic force microscopy. Two types of step edges are identified: internal (formed during crystal growth) and external (formed by mechanical cleavage of bulk HOPG). The external steps exhibit higher friction than the internal steps due to the broken bonds of the exposed edge C atoms, while carbon atoms in the internal steps are not exposed. The reactivity of the atomic steps is manifested in a variety of ways, including the preferential attachment of Pt nanoparticles deposited on HOPG when using atomic layer deposition and KOH clusters formed during drop casting from aqueous solutions. These phenomena imply that only external atomic steps can be used for selective electrodeposition for nanoscale electronic devices.
1993-12-01
Longitudinal) E3 Fatigue Crack Growth Rate Data for Alcan 8090-T8 160 1 " x 4" Extrusion ( L-T Orientation). Grumman E4 Fatigue Crack Growth Rate...Data for Alcan 8090-T8 161 1 " x 4" Extrusion (T-L Orientation). Grumman E5 Fatigue Crack Growth Rate Data for Alcan 8090-T651 162 1 "x 4" Extrusion (L-T...Orientation). Northrop E6 Fatigue Crack Growth Rate for Alcan 8090-T651 163 1 " x 4" Extrusion (T-L Orientation). Northrop E7 Fatigue Crack Growth Rate
Cusinato, Maria; Calvo, Vincenzo; Bisogno, Gianni; Viscardi, Elisabetta; Pillon, Marta; Opocher, Enrico; Basso, Giuseppe; Montanaro, Maria
2017-01-01
To investigate the impact of childhood cancer on parents' adult attachment, social support, marital adjustment, anxiety, and depression. 30 parents of children with childhood cancer and 30 matched controls completed the following questionnaires: Experiences in Close Relationships-Revised, Dyadic Adjustment Scale-4, Multidimensional Scale of Perceived Social Support, State-Trait Anxiety Inventory - form Y, and Beck Depression Inventory. Parents of children with childhood cancer had a significantly lower dyadic adjustment than controls, and higher levels of insecure-avoidant attachment, state anxiety, and depression. It is important for health-care personnel to take into account these parents' propensity to show increased levels of avoidant attachment during children's treatment to foster effective communication and supportive relationships between clinicians, pediatric patients, and parents.
USDA-ARS?s Scientific Manuscript database
Listeria monocytogenes can colonize a poultry processing or further processing plant as a resident in floor drains. Limiting growth and attachment to drain surfaces may help lessen the potential for cross contamination of product. The objective of this study was to compare a synthetic hydrogen per...
Investigation of Polyurea-Crosslinked Silica Aerogels as a Neuronal Scaffold: A Pilot Study
Sabri, Firouzeh; Cole, Judith A.; Scarbrough, Michael C.; Leventis, Nicholas
2012-01-01
Background Polymer crosslinked aerogels are an attractive class of materials for future implant applications particularly as a biomaterial for the support of nerve growth. The low density and nano-porous structure of this material combined with large surface area, high mechanical strength, and tunable surface properties, make aerogels materials with a high potential in aiding repair of injuries of the peripheral nervous system. However, the interaction of neurons with aerogels remains to be investigated. Methodology In this work the attachment and growth of neurons on clear polyurea crosslinked silica aerogels (PCSA) coated with: poly-L-lysine, basement membrane extract (BME), and laminin1 was investigated by means of optical and scanning electron microscopy. After comparing the attachment and growth capability of neurons on these different coatings, laminin1 and BME were chosen for nerve cell attachment and growth on PCSA surfaces. The behavior of neurons on treated petri dish surfaces was used as the control and behavior of neurons on treated PCSA discs was compared against it. Conclusions/Significance This study demonstrates that: 1) untreated PCSA surfaces do not support attachment and growth of nerve cells, 2) a thin application of laminin1 layer onto the PCSA discs adhered well to the PCSA surface while also supporting growth and differentiation of neurons as evidenced by the number of processes extended and b3-tubulin expression, 3) three dimensional porous structure of PCSA remains intact after fixing protocols necessary for preservation of biological samples and 4) laminin1 coating proved to be the most effective method for attaching neurons to the desired regions on PCSA discs. This work provides the basis for potential use of PCSA as a biomaterial scaffold for neural regeneration. PMID:22448239
Panwivia, Supaporn; Sirvithayapakorn, Sanya; Wantawin, Chalermraj; Noophan, Pongsak Lek; Munakata-Marr, Junko
2014-01-01
Attached growth-systems for the anaerobic ammonium oxidation (anammox) process have been postulated for implementation in the field. However, information about the anammox process in attached growth-systems is limited. This study compared nitrogen removal rates and nitrous oxide (N2O) production of enriched anammox cultures in both suspended and attached growth sequencing batch reactors (SBRs). Suspended growth reactors (SBR-S) and attached growth reactors using polystyrene sponge as a medium (SBR-A) were used in these experiments. After inoculation with an enriched anammox culture, significant nitrogen removals of ammonium (NH4 (+)) and nitrite (NO2 (-)) were observed under NH4 (+):NO2 (-) ratios ranging from 1:1 to 1:2 in both types of SBRs. The specific rates of total nitrogen removal in SBR-S and SBR-A were 0.52 mg N/mg VSS-d and 0.44 mg N/mg VSS-d, respectively, at an NH4 (+):NO2 (-) ratio of 1:2. N2O production by the enriched anammox culture in both SBR-S and SBR-A was significantly higher at NH4 (+):NO2 (-) ratio of 1:2 than at NH4 (+):NO2 (-) ratios of 1:1 and 1:1.32. In addition, N2O production was higher at a pH of 6.8 than at pH 7.3, 7.8, and 8.3 in both SBR-S and SBR-A. The results of this investigation demonstrate that the anammox process may avoid N2O emission by maintaining an NH4 (+):NO2 (-) ratio of less than 1:2 and pH higher than 6.8.
The associations between adult attachment, posttraumatic symptoms, and posttraumatic growth.
Arikan, Gizem; Stopa, Lusia; Carnelley, Katherine B; Karl, Anke
2016-01-01
Individual differences after trauma vary considerably and can range from posttraumatic stress disorder (PTSD) to posttraumatic growth (PTG). Current theoretical models cannot fully explain this variability. Therefore, we integrated attachment theory with Ehlers and Clark's model of PTSD to understand whether attachment style is associated with negative appraisals of a traumatic event(s), posttraumatic stress symptoms (PTS), and PTG. Our aim was to test this integrated model PTSD in an analog sample who had experienced at least one traumatic event. We used structural equation modeling to test the association of adult attachment and posttraumatic cognitions (self and world/others) with PTS and PTG using a cross-sectional, correlational design. The sample comprised 393 university staff and students (RangeAge= 18-49, 85% females) who completed online measures. Attachment anxiety and negative posttraumatic self-cognitions were positively associated. Negative posttraumatic self-cognitions were positively associated with PTS. Attachment anxiety had an indirect effect (via negative posttraumatic self-cognitions) on PTS, whereas attachment avoidance predicted more negative posttraumatic world cognitions and lower perceived PTG. The study highlights the importance of considering how attachment styles influence posttraumatic emotion regulation and cognitive processing of the trauma to determine posttraumatic mental health.
Effects of nisin on growth of bacteria attached to meat.
Chung, K T; Dickson, J S; Crouse, J D
1989-01-01
Nisin had an inhibitory effect on gram-positive bacteria (Listeria monocytogenes, Staphylococcus aureus, and Streptococcus lactis) but did not have an inhibitory effect on gram-negative bacteria (Serratia marcescens, Salmonella typhimurium, and Pseudomonas aeruginosa) attached to meat. Nisin delayed bacterial growth on meats which were artificially inoculated with L. monocytogenes or Staphylococcus aureus for at least 1 day at room temperature. If the incubation temperature was 5 degrees C, growth of L. monocytogenes was delayed for more than 2 weeks, and growth of Staphylococcus aureus did not occur. We also found that the extractable activity of nisin decreased rapidly when the meats were incubated at ambient temperatures and that this decrease was inversely related to the observed inhibitory effect. These findings disclosed that nisin delays the growth of some gram-positive bacteria attached to meat. However, nisin alone may not be sufficient to prevent meat spoilage because of the presence of gram-negative and other nisin-resistant gram-positive bacteria. PMID:2764559
Step Permeability on the Pt(111) Surface
NASA Astrophysics Data System (ADS)
Altman, Michael
2005-03-01
Surface morphology will be affected, or even dictated, by kinetic limitations that may be present during growth. Asymmetric step attachment is recognized to be an important and possibly common cause of morphological growth instabilities. However, the impact of this kinetic limitation on growth morphology may be hindered by other factors such as the rate limiting step and step permeability. This strongly motivates experimental measurements of these quantities in real systems. Using low energy electron microscopy, we have measured step flow velocities in growth on the Pt(111) surface. The dependence of step velocity upon adjacent terrace width clearly shows evidence of asymmetric step attachment and step permeability. Step velocity is modeled by solving the diffusion equation simultaneously on several adjacent terraces subject to boundary conditions at intervening steps that include asymmetric step attachment and step permeability. This analysis allows a quantitative evaluation of step permeability and the kinetic length, which characterizes the rate limiting step continuously between diffusion and attachment-detachment limited regimes. This work provides information that is greatly needed to set physical bounds on the parameters that are used in theoretical treatments of growth. The observation that steps are permeable even on a simple metal surface should also stimulate more experimental measurements and theoretical treatments of this effect.
Assembly of Oriented Virus Arrays by Chemo-Selective Ligation Methods and Nanolithography Techniques
DOE Office of Scientific and Technical Information (OSTI.GOV)
Camarero, J A; Cheung, C L; Lin, T
2002-12-02
The present work describes our ongoing efforts towards the creation of nano-scaled ordered arrays of protein/virus covalently attached to site-specific chemical linkers patterned by different nanolithograpy techniques. We will present a new and efficient solid-phase approach for the synthesis of chemically modified long alkyl-thiols. These compounds can be used to introduce chemoselective reacting groups onto gold and silicon-based surfaces. Furthermore, these modified thiols have been used to create nanometric patterns by using different nanolithography techniques. We will show that these patterns can react chemoselectively with proteins and/or virus which have been chemically or recombinantly modified to contain complementary chemical groupsmore » at specific positions thus resulting in the oriented attachment of the protein or virus to the surface.« less
NASA Technical Reports Server (NTRS)
Penn, B. G.; Shields, A.; Frazier, D. O.
1988-01-01
Methods for the growth of polydiacetylene thin films by melt and vapor growth and their subsequent polymerization are summarized. Films with random orientations were obtained when glass or quartz were used as substrates in the vapor growth process. Oriented polydiacetylene films were fabricated by the vapor deposition of diacetylene monomer onto oriented polydiacetylene on a glass substrate and its subsequent polymerization by UV light. A method for the growth of oriented thin films by a melt-shear growth process as well as a method of film growth by seeded recrstallization from the melt between glass plates, that may be applied to the growth of polydiacetylene films, are described. Moreover, a method is presented for the fabrication of single crystal thin films of polyacetylenes by irradiation of the surface of diacetylene single crystals to a depth between 100 and 2000 angstroms.
ERIC Educational Resources Information Center
Kelley, Melissa M.; Chan, Keith T.
2012-01-01
Research has examined the relationship of styles of attachment to others and meaning with grief and the stress-related growth process. Less has been written on styles of attachment to God and patterns of religious coping and how these constructs may impact adjustment in persons dealing with loss. This study examines the roles of attachment to God,…
Cook, Stephanie H; Calebs, Benjamin J
2016-01-01
Gay and bisexual boys and men experience social stigma associated with their sexual minority status that can negatively influence health. In addition, experiencing sexual orientation stigma may be linked to a decreased capacity to effectively form and maintain secure attachment relationships with parents, peers, and romantic partners across the life-course. We proposed that utilizing a framework that integrates the process by which sexual minority men develop attachment relationships in the context of sexual minority stress can lead to a better understanding of health and well-being among sexual minority boys and men. In addition, we highlight where future research can expand upon the presented model in order to better understand the developmental processes through which attachment and sexual minority stress influences health and health behaviors among sexual minority boys and men.
Vasileva, Mira; Petermann, Franz
2016-09-22
A proper preparation for foster parents to care for abused and neglected children includes effective training and initial diagnostics in order to plan individual treatment. Hence, a basic knowledge about the main psychosocial and developmental problems associated with abuse and neglect and their prevalence in foster children is needed. For this purpose, a systematical literature review and a series of meta-analyses were conducted. A total of 25 studies reporting data on development (n = 4,033), mental health (n = 726), and attachment (n = 255) of foster children in preschool age met the inclusion criteria. The meta-analyses indicated prevalence rates of approximately 40% for developmental, mental health problems, and insecure attachment. Rates of disorganized attachment were estimated to 22%. These findings outline the necessity of an initial trauma-oriented diagnostics and trainings for foster parents that address foster children's development, mental health, and disorganized attachment. © The Author(s) 2016.
Calebs, Benjamin
2016-01-01
Gay and bisexual boys and men experience social stigma associated with their sexual minority status that can negatively influence health. In addition, experiencing sexual orientation stigma may be linked to a decreased capacity to effectively form and maintain secure attachment relationships with parents, peers and romantic partners across the life-course. We proposed that utilizing a framework that integrates the process by which sexual minority men develop attachment relationships in the context of sexual minority stress can lead to a better understanding of health and well-being among sexual minority men. In addition, we highlight where future research can expand upon the presented model in order to better understand the developmental processes through which attachment and sexual minority stress influences health and health behaviors among sexual minority young adult men. PMID:27337620
Effect of Micro- and Nanoscale Topography on the Adhesion of Bacterial Cells to Solid Surfaces
Hsu, Lillian C.; Fang, Jean; Borca-Tasciuc, Diana A.; Worobo, Randy W.
2013-01-01
Attachment and biofilm formation by bacterial pathogens on surfaces in natural, industrial, and hospital settings lead to infections and illnesses and even death. Minimizing bacterial attachment to surfaces using controlled topography could reduce the spreading of pathogens and, thus, the incidence of illnesses and subsequent human and financial losses. In this context, the attachment of key microorganisms, including Escherichia coli, Listeria innocua, and Pseudomonas fluorescens, to silica and alumina surfaces with micron and nanoscale topography was investigated. The results suggest that orientation of the attached cells occurs preferentially such as to maximize their contact area with the surface. Moreover, the bacterial cells exhibited different morphologies, including different number and size of cellular appendages, depending on the topographical details of the surface to which they attached. This suggests that bacteria may utilize different mechanisms of attachment in response to surface topography. These results are important for the design of novel microbe-repellant materials. PMID:23416997
Granqvist, Pehr; Mikulincer, Mario; Gewirtz, Vered; Shaver, Phillip R
2012-11-01
Four studies examined implications of attachment theory for psychological aspects of religion among Israeli Jews. Study 1 replicated previous correlational findings indicating correspondence among interpersonal attachment orientations, attachment to God, and image of God. Studies 2-4 were subliminal priming experiments, which documented both normative and individual-difference effects. Regarding normative effects, findings indicated that threat priming heightened cognitive access to God-related concepts in a lexical decision task (Study 2); priming with "God" heightened cognitive access to positive, secure base-related concepts in the same task (Study 3); and priming with a religious symbol caused neutral material to be better liked (Study 4). Regarding individual differences, interpersonal attachment-related avoidance reduced the normative effects (i.e., avoidant participants had lower implicit access to God as a safe haven and secure base). Findings were mostly independent of level of religiousness. The present experiments considerably extend the psychological literature on connections between attachment constructs and aspects of religion. (c) 2012 APA, all rights reserved.
Effects of microstructure banding on hydrogen assisted fatigue crack growth in X65 pipeline steels
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ronevich, Joseph A.; Somerday, Brian P.; San Marchi, Chris W.
Banded ferrite-pearlite X65 pipeline steel was tested in high pressure hydrogen gas to evaluate the effects of oriented pearlite on hydrogen assisted fatigue crack growth. Test specimens were oriented in the steel pipe such that cracks propagated either parallel or perpendicular to the banded pearlite. The ferrite-pearlite microstructure exhibited orientation dependent behavior in which fatigue crack growth rates were significantly lower for cracks oriented perpendicular to the banded pearlite compared to cracks oriented parallel to the bands. Thus the reduction of hydrogen assisted fatigue crack growth across the banded pearlite is attributed to a combination of crack-tip branching and impededmore » hydrogen diffusion across the banded pearlite.« less
Effects of microstructure banding on hydrogen assisted fatigue crack growth in X65 pipeline steels
Ronevich, Joseph A.; Somerday, Brian P.; San Marchi, Chris W.
2015-09-10
Banded ferrite-pearlite X65 pipeline steel was tested in high pressure hydrogen gas to evaluate the effects of oriented pearlite on hydrogen assisted fatigue crack growth. Test specimens were oriented in the steel pipe such that cracks propagated either parallel or perpendicular to the banded pearlite. The ferrite-pearlite microstructure exhibited orientation dependent behavior in which fatigue crack growth rates were significantly lower for cracks oriented perpendicular to the banded pearlite compared to cracks oriented parallel to the bands. Thus the reduction of hydrogen assisted fatigue crack growth across the banded pearlite is attributed to a combination of crack-tip branching and impededmore » hydrogen diffusion across the banded pearlite.« less
USDA-ARS?s Scientific Manuscript database
Reniform nematodes (Rotylenchulus reniformis) from pot culture were attached with in vitro produced Pasteuria spp. spores using a centrifuge attachment technique that resulted in 40-50% of the vermiform nematodes with spores adhering to their cuticles. Attached nematodes were placed into small plast...
Attachment Style and Less Severe Forms of Sexual Coercion: A Systematic Review.
Karantzas, Gery C; McCabe, Marita P; Karantzas, Kellie M; Pizzirani, Bengianni; Campbell, Hilary; Mullins, Ellie R
2016-07-01
Few studies have examined how attachment insecurity (i.e., attachment anxiety, attachment avoidance) is associated with the more subtle and less severe forms of sexual coercion, such as verbal threats and partner manipulation. This is despite the fact that past research has indicated some of the relationship behaviors exhibited by insecurely attached individuals represent behaviors indicative of either the perpetration or victimization of less severe forms of sexual coercion. The aim of this study was to conduct a systematic review on the association between attachment style and less severe forms of sexual coercion. Our search, which included published journal papers, book chapters, and theses published between January 1970 and October 2014, yielded 1091 records. Examination of these records against exclusion criteria yielded 11 studies that focused on the associations between attachment orientation and perpetration of sexual coercion (n = 3), sexual coercion victimization (n = 3), or both perpetration and victimization (n = 5). Findings revealed that attachment anxiety appeared to be more consistently associated with being the victim of sexual coercion than attachment avoidance. In terms of perpetration, attachment avoidance was more consistently associated with sexual coercion. These findings were observed when examining the association between attachment dimensions and motives for sexual coercion. The findings also revealed gender to be a moderator for victimization. This review provides insights into how attachment style may influence the perpetration and victimization of sexual coercion.
NASA Astrophysics Data System (ADS)
van der Heide, Uulke A.; Gerritsen, Hans C.; Trayer, Ian P.; Levine, Yehudi K.
1992-04-01
The time-resolved fluorescence anisotropy of myosin S1 covalently labeled with Eosin-5- maleimide and 1,5-I-AEDANS was measured in solution. Each probe was specifically attached at one SH-group on the S1. The two most reactive SH sites on the heavy chain of the myosin S1 were used. The fluorescence anisotropy was measured at different excitation wavelengths. In this way, several absorption moments were utilized, each having a distinct orientation in the frame of the dye. The orientations of the transition moments in the dyes were determined in a separate experiment using an angle resolved fluorescence depolarization experiment on dyes embedded in stretched matrices of PVA polymers. The anisotropy decay curves exhibit fast (<3 ns) and slow (> 100 ns) components. The slow decay components reflect the motion of the large protein molecules. The fast anisotropy decay are attributed to a fast, but restricted, motion of the bound dye relative to the protein as experiments on free dyes in solution reveal subnanosecond anisotropy decays. The anisotropy decays have been analyzed in terms of a model which describes the restricted motion of the dye molecule relative to the protein and the overall rotation of the dye-protein complex in solution. An important element in the model is the incorporation of the orientational distribution of the dye relative to the protein. The observed anisotropy decays were analyzed using a global target approach in which the experimental data obtained at different excitation wavelengths are fitted simultaneously to the theoretical model. It is important to note that the orientational distribution of the dye relative to the protein, as well as the rotational correlation times of the motions for a dye attached to a given binding site, are independent of the excitation wavelength used. This leads to a reduction in the number of independent parameters optimized by the nonlinear least squares procedure. The orientational distribution of the dye relative to the protein obtained in this way is particularly useful for the interpretation of fluorescence depolarization data obtained from labeled muscle fibers. Indeed, knowledge of the distribution function of a dye attached to a binding site of the S1 protein is a prerequisite for a probe-independent determination of the orientational distribution of the S1 proteins themselves in the muscle fiber.
Ridge, S R; Feeney, J A
1998-12-01
The objective of the present study was to assess the applicability of attachment theory to the relationships of gay males and lesbians, with particular emphasis on parental relationships, relationship satisfaction, sexual attitudes and 'coming out' as being homosexual. Gay males (n = 77) and lesbians (n = 100) completed questionnaires assessing attachment style, working models of attachment, early relationships with parents and relationship history, status and functioning. A comparison sample of heterosexual participants completed measures of attachment style and relationship history. Relative frequencies of attachment styles were similar for homosexual and heterosexual samples. Contrary to previous research using largely heterosexual respondents, no link between early parenting and attachment style was found. However, homosexual males reported more positive early relationships with mothers than did females. Associations of attachment style with working models, relationship variables and sexual attitudes largely supported those based on heterosexual samples. Gender and attachment style differences were found in reported effects of 'coming out' on relationships with parents. Overall, the results suggest that insecure attachment may not be over-represented in gay and lesbian samples, but that insecurity is associated with less relationship satisfaction and with problems related to the disclosure of sexual orientation. The implications of these findings for research and clinical practice are addressed.
Syngouna, Vasiliki I; Chrysikopoulos, Constantinos V
2016-03-01
The cotransport of clay colloids and viruses in vertically oriented laboratory columns packed with glass beads was investigated. Bacteriophages MS2 and ΦX174 were used as model viruses, and kaolinite (ΚGa-1b) and montmorillonite (STx-1b) as model clay colloids. A steady flow rate of Q=1.5 mL/min was applied in both vertical up (VU) and vertical down (VD) flow directions. In the presence of KGa-1b, estimated mass recovery values for both viruses were higher for VD than VU flow direction, while in the presence of STx-1b the opposite was observed. However, for all cases examined, the produced mass of viruses attached onto suspended clay particles were higher for VD than VU flow direction, suggesting that the flow direction significantly influences virus attachment onto clays, as well as packed column retention of viruses attached onto suspended clays. KGa-1b hindered the transport of ΦX174 under VD flow, while STx-1b facilitated the transport of ΦX174 under both VU and VD flow directions. Moreover, KGa-1b and STx-1b facilitated the transport of MS2 in most of the cases examined except of the case where KGa-1b was present under VD flow. Also, the experimental data were used for the estimation of virus surface-coverages and virus surface concentrations generated by virus diffusion-limited attachment, as well as virus attachment due to sedimentation. Both sedimentation and diffusion limited virus attachment were higher for VD than VU flow, except the case of MS2 and STx-1b cotransport. The diffusion-limited attachment was higher for MS2 than ΦΧ174 for all cases examined. Copyright © 2015 Elsevier B.V. All rights reserved.
Nakagawa, Yoshitaka; Kageyama, Hiroyuki; Oaki, Yuya; Imai, Hiroaki
2015-06-09
Monocrystalline architectures with well-defined shapes were achieved by bottom-up routes through epitaxial attachment of Mn3O4 nanocrystals. The crystallographically continuous 1D chains elongated in the a axis and 2D panels having large a or c faces were obtained by removal of the organic mediator from surfactant-mediated 1D and 2D arrays of Mn3O4 nanocrystals, respectively. Our basal approach indicates that the epitaxial attachment through the surfactant-mediated arrays is utilized for fabrication of a wide variety of micrometric architectures from nanometric crystalline units.
[Sibling relations from the family therapy perspective--support, attachment, rivalry and envy].
Cierpka, M
2001-01-01
In family therapy, during the last years more and more importance is attached to the dynamics of the sibling subsystem. In the present paper differences between them as well as similarities are discussed from the point of view of family theory. Relevant dimensions like support, attachment, rivalry and envy between brothers and sisters contribute essentially to the family dynamics. In this clinically orientated paper, we describe by means of a case example how the couple's conflicts after their separation is unconsciously repeated in the sibling subsystem. It is shown how the intergenerational dynamics can be interrupted by the initiative of the children and the initiated family therapy.
Jia, Yuncheng; Cheng, Gang; Zhang, Dajun; Ta, Na; Xia, Mu; Ding, Fangyuan
2017-01-01
Objective: To determine the influence of adult attachment orientations on infant preference. Methods: We adopted eye-tracking technology to monitor childless college women’s eye movements when looking at pairs of faces, including one adult face (man or woman) and one infant face, with three different expressions (happy, sadness, and neutral). The participants (N = 150; 84% Han ethnicity) were aged 18–29 years (M = 19.22, SD = 1.72). A random intercepts multilevel linear regression analysis was used to assess the unique contribution of attachment avoidance, determined using the Experiences in Close Relationships scale, to preference for infant faces. Results: Women with higher attachment avoidance showed less infant preference, as shown by less sustained overt attentional bias to the infant face than the adult face based on fixation time and count. Conclusion: Adult attachment might be related to infant preference according to eye movement indices. Women with higher attachment avoidance may lack attentional preference for infant faces. The findings may aid the treatment and remediation of the interactions between children and mothers with insecure attachment. PMID:28184210
Jia, Yuncheng; Cheng, Gang; Zhang, Dajun; Ta, Na; Xia, Mu; Ding, Fangyuan
2017-01-01
Objective: To determine the influence of adult attachment orientations on infant preference. Methods: We adopted eye-tracking technology to monitor childless college women's eye movements when looking at pairs of faces, including one adult face (man or woman) and one infant face, with three different expressions (happy, sadness, and neutral). The participants ( N = 150; 84% Han ethnicity) were aged 18-29 years ( M = 19.22, SD = 1.72). A random intercepts multilevel linear regression analysis was used to assess the unique contribution of attachment avoidance, determined using the Experiences in Close Relationships scale, to preference for infant faces. Results: Women with higher attachment avoidance showed less infant preference, as shown by less sustained overt attentional bias to the infant face than the adult face based on fixation time and count. Conclusion: Adult attachment might be related to infant preference according to eye movement indices. Women with higher attachment avoidance may lack attentional preference for infant faces. The findings may aid the treatment and remediation of the interactions between children and mothers with insecure attachment.
Zhuang, Zanyong; Xu, Xinjiang; Wang, Yongjing; Wang, Yandi; Huang, Feng; Lin, Zhang
2012-04-15
The treatment of industrial sludge containing amorphous/nanophase metal oxides or hydroxides is one of the vital issues in hazardous waste disposal. In this work, we developed a strategy to recycle nano-SnO(2) from tinplate electroplating sludge. It revealed that the major components of this sludge were acid soluble Sn and Fe amorphous phases. By introducing NaOH as a mineralizer, a fast growth of amorphous Sn compound into acid-insoluble SnO(2) nanowires was achieved selectively. Thus, the as-formed nano-SnO(2) could be recycled via dissolving other solid compositions in the sludge by using acid. The role of NaOH on accelerating both the Oriented Attachment (OA) and Ostwald Ripening (OR) growth of SnO(2) was discussed, which was regarded as a critical factor for treating the sludge. A pilot-scale experiment was conducted to treat 2.3 kg original sludge and the recycling of about 90 g nano-SnO(2) was achieved. We anticipate this work can provide a good example for the recycling of valuable metals from industrial sludge containing fine metal oxides or hydroxides. Copyright © 2011 Elsevier B.V. All rights reserved.
Yu, Ermeng; Xie, Jun; Wang, Jinlin; Ako, Harry; Wang, Guangjun; Chen, Zhanghe; Liu, Yongfeng
2016-07-01
Bacteria play crucial roles in the combined system of substrate addition and C/N control, which has been demonstrated to improve aquaculture production. However, the complexity of surface-attached bacteria on substrates and suspended bacteria in the water column hamper further application of this system. This study firstly applied this combined system into the culture of grass carp, and then explored the relationship between microbial complexes from surface-attached and suspended bacteria in this system and the production of grass carp. In addition, this study investigated bacterial community structures as affected by four C/N ratios using Illumina sequencing technology. The results demonstrated that the weight gain rate and specific growth rate of grass carp in the CN20 group (C/N ratio 20:1) were the highest (P < 0.05), and dietary supplementation of the microbial complex had positive effects on the growth of grass carp (P < 0.05). Sequencing data revealed that, (1) the proportions of Verrucomicrobiae and Rhodobacter (surface-attached), sediminibacterium (suspended), and emticicia (surface-attached and suspended) were much higher in the CN20 group compared with those in the other groups (P < 0.05); (2) Rhodobacter, Flavobacterium, Acinetobacter, Pseudomonas, Planctomyces, and Cloacibacterium might be important for the microbial colonization on substrates; (3) as the C/N ratio increased, proportions of Hydrogenophaga (surface-attached and suspended), Zoogloea, and Flectobacillus (suspended) increased, but proportions of Bacillus, Clavibacter, and Cellvibro (surface-attached and suspended) decreased. In summary, a combined system of substrate addition and C/N control increased the production of grass carp, and Verrucomicrobiae and Rhodobacter in the surface-attached bacterial community were potential probiotic bacteria that contributed to the enhanced growth of grass carp.
Limited period of graviresponsiveness in germinating spores of Ceratopteris richardii
NASA Technical Reports Server (NTRS)
Edwards, E. S.; Roux, S. J.
1994-01-01
Rhizoids of the fern Ceratopteris richardii Brogn. usually emerge 40 h after germination is initiated by light, and more than 90% of them emerge growing in a downward direction. However, when the spores are germinated on a clinostat, the emerging rhizoids show no preferential orientation. This indicates that under normal 1 g conditions the initial growth direction of rhizoids can be oriented by gravity. If the orientation of the spores is changed 3 h or less after the start of germination, the growth direction of most emerging rhizoids becomes downward relative to the new orientation. However, if the orientation of the spores is changed by 180 degrees 8 h or more after germination is initiated by light, most rhizoids emerge growing upward; i.e., the same direction as if there had been no orientation change. Emerged rhizoids also do not change their direction of growth if their orientation is changed. These results indicate that the growth direction of emerging rhizoids is set by gravity prior to actual emergence, and that the time of full orientation responsiveness is limited to a period ranging from the initiation of germination to about 3-4 h after the start of germination. There is a gravity-oriented nuclear movement beginning at about 13 h after germination, and this movement appears to predict the initial growth direction of rhizoids.
Limited period of graviresponsiveness in germinating spores of Ceratopteris richardii.
Edwards, E S; Roux, S J
1994-01-01
Rhizoids of the fern Ceratopteris richardii Brogn. usually emerge 40 h after germination is initiated by light, and more than 90% of them emerge growing in a downward direction. However, when the spores are germinated on a clinostat, the emerging rhizoids show no preferential orientation. This indicates that under normal 1 g conditions the initial growth direction of rhizoids can be oriented by gravity. If the orientation of the spores is changed 3 h or less after the start of germination, the growth direction of most emerging rhizoids becomes downward relative to the new orientation. However, if the orientation of the spores is changed by 180 degrees 8 h or more after germination is initiated by light, most rhizoids emerge growing upward; i.e., the same direction as if there had been no orientation change. Emerged rhizoids also do not change their direction of growth if their orientation is changed. These results indicate that the growth direction of emerging rhizoids is set by gravity prior to actual emergence, and that the time of full orientation responsiveness is limited to a period ranging from the initiation of germination to about 3-4 h after the start of germination. There is a gravity-oriented nuclear movement beginning at about 13 h after germination, and this movement appears to predict the initial growth direction of rhizoids.
DisAp-dependent striated fiber elongation is required to organize ciliary arrays
Galati, Domenico F.; Bonney, Stephanie; Kronenberg, Zev; Clarissa, Christina; Yandell, Mark; Elde, Nels C.; Jerka-Dziadosz, Maria; Giddings, Thomas H.; Frankel, Joseph
2014-01-01
Cilia-organizing basal bodies (BBs) are microtubule scaffolds that are visibly asymmetrical because they have attached auxiliary structures, such as striated fibers. In multiciliated cells, BB orientation aligns to ensure coherent ciliary beating, but the mechanisms that maintain BB orientation are unclear. For the first time in Tetrahymena thermophila, we use comparative whole-genome sequencing to identify the mutation in the BB disorientation mutant disA-1. disA-1 abolishes the localization of the novel protein DisAp to T. thermophila striated fibers (kinetodesmal fibers; KFs), which is consistent with DisAp’s similarity to the striated fiber protein SF-assemblin. We demonstrate that DisAp is required for KFs to elongate and to resist BB disorientation in response to ciliary forces. Newly formed BBs move along KFs as they approach their cortical attachment sites. However, because they contain short KFs that are rotated, BBs in disA-1 cells display aberrant spacing and disorientation. Therefore, DisAp is a novel KF component that is essential for force-dependent KF elongation and BB orientation in multiciliary arrays. PMID:25533842
Electromagnetic (EM) Wave Attachment to Laser Plasma Filaments
2009-05-01
this phenomenon over a laboratory scale distance and observed that the channel energy, diameter, and modulated spectrum all remained relatively ...are oriented parallel to one another and insulated from one another to maintain a calculated separation. The TEM waves also represent plane waves...orientation, the electric field will point along the direction of the wire axis. The wire is 0.8 mm copper wire, fixed at both ends and insulated at
Controlling Growth Orientation of Phthalocyanine Films by Electrical Fields
NASA Technical Reports Server (NTRS)
Zhu, S.; Banks, C. E.; Frazier, D. O.; Ila, D.; Muntele, I.; Penn, B. G.; Sharma, A.; Rose, M. Franklin (Technical Monitor)
2001-01-01
Organic Phthalocyanine films have many applications ranging from data storage to various non-linear optical devices whose quality is affected by the growth orientation of Phthalocyanine films. Due to the structural and electrical properties of Phthalocyanine molecules, the film growth orientation depends strongly on the substrate surface states. In this presentation, an electrical field up to 4000 V/cm is introduced during film growth. The Phthalocyanine films are synthesized on quartz substrates using thermal evaporation. An intermediate layer is deposited on some substrates for introducing the electrical field. Scanning electron microscopy, x-ray diffraction, and Fourier transform infrared spectroscopy are used for measuring surface morphology, film structure, and optical properties, respectively. The comparison of Phthalocyanine films grown with and without the electrical field reveals different morphology, film density, and growth orientation, which eventually change optical properties of these films. These results suggest that the growth method in the electrical field can be used to synthesized Phthalocyanine films with a preferred crystal orientation as well as propose an interaction mechanism between the substrate surface and the depositing molecules. The details of growth conditions and of the growth model of how the Phthalocyanine molecules grow in the electrical field will be discussed.
Koós, O; Gergely, G
2001-01-01
The authors present a new approach to the etiology of disorganized attachment based on contingency detection theory. According to this view, the relevant common factor in parental maltreatment and unresolved loss that leads to disorganized attachment has to do with the type of "deviant contingency environment" that both of these conditions generate. In such environments, infants experience periods of being in control followed by periods of sudden loss of control over the caregiver's behavior. The authors hypothesize that this adversely affects the developmental unfolding of the infant's innate "contingency detection module" (Gergely & Watson, 1999), which normally involves a maturational shift around 3 months from an initial attention bias for perfectly contingent stimulation to an emerging preference for less-than-perfect social contingencies. The periodically changing controllability of abusive and dissociating "unresolved" attachment figures is hypothesized to block this process and to lead to the defensive fixation of a dysfunctional "flickering contingency switch" mechanism with two dominant and competing target positions (self-oriented vs. other-oriented). This results in the dissociative style of attention and behavioral organization characteristic of disorganized infant attachment. The authors summarize the preliminary results of an empirical study that provides support for this model in 6.5-month-old infants using a modified Still-Face situation (the Mirror Interaction Situation). The study demonstrates differential emotional and behavioral reactions to sudden loss of maternal contingency and a specific interest in exploring the perfectly contingent self-image in the mirror in infants who at 12 months become categorized as "disorganized" in the Strange Situation.
Kimura, Atsushi; Kuwazawa, Shigetaka; Wada, Yuji; Kyutoku, Yasushi; Okamoto, Masako; Yamaguchi, Yui; Masuda, Tomohiro; Dan, Ippeita
2011-04-01
The effect of sensory and extrinsic attributes on consumer intentions to purchase the Japanese traditional fermented soybean product natto was evaluated using conjoint analysis. Six attributes with 2 levels each were chosen and manipulated: price (high compared with low), the country of origin of the soybeans (domestic compared with imported), stickiness (strong compared with moderate), smell (rich compared with moderate), attached seasonings (attached compared with no attached seasonings), and the environmental friendliness of the packaging (high compared with low). A fractional factorial design was applied and 8 hypothetical product labels were produced. A sample of 479 Japanese housewives ranked these product labels based on their purchase intentions. Overall purchase intention was affected by country of origin, attached seasonings, and price; those attributes accounted for 81.0%, while the sensory attributes of the product accounted for 19.0% of purchase intents. In order to estimate market segments for the natto products based on consumer preference, a cluster analysis was performed. It identified 4 segments of consumers: 1 oriented to attached seasonings, another conscious of the price, and the other 2 oriented to origins. The behavioral and demographic characteristics of the respondents had a limited influence on segment membership. This research was conducted to understand how consumers valuate various sensory and nonsensory product attributes based on their assessment of the overall product in the case of Japanese fermented soy product (natto). The data of this research would be of great importance both in understanding consumer behavior and in designing strategies for product development.
NASA Astrophysics Data System (ADS)
Seo, Yeonwoo; Lee, Sanghwa; Jue, Miyeon; Yoon, Hansub; Kim, Chinkyo
2012-12-01
Over a wide range of growth conditions, GaN domains were grown on bare m-plane sapphire substrates by using hydride vapor phase epitaxy (HVPE), and the relation between these growth conditions and three possible preferred crystallographic orientations ([1100], [1103], [1122]) of GaN domains was investigated. In contrast with the previous reports by other groups, our results revealed that preferentially [1100]-oriented GaN domains were grown without low-temperature nitridation or a buffer layer, and that the growth condition of preferentially [1100]-oriented GaN was insensitive to V/III ratio.
Nakano, Tomoyuki; Kanai, Yoshihiko; Amano, Yusuke; Yoshimoto, Taichiro; Matsubara, Daisuke; Shibano, Tomoki; Tamura, Tomoko; Oguni, Sachiko; Katashiba, Shizuka; Ito, Takeshi; Murakami, Yoshinori; Fukayama, Masashi; Murakami, Takashi; Endo, Shunsuke; Niki, Toshiro
2017-01-01
Decreased cell-substratum adhesion is crucially involved in metastasis. Previous studies demonstrated that lung cancer with floating cell clusters in histology is more likely to develop metastasis. In the present study, we investigated whether cancer cells in long-term, three-dimensional low attachment cultures acquire high metastatic potential; these cells were then used to examine the mechanisms underlying metastasis. Two KRAS-mutated adenocarcinoma cell lines (A549 and H441) were cultured and selected on ultra-low attachment culture dishes, and the resulting cells were defined as FL (for floating) sublines. Cancer cells were inoculated into NOD/SCID mice via an intracardiac injection, and metastasis was evaluated using luciferase-based imaging and histopathology. In vitro cell growth (in attachment or suspension cultures), migration, and invasion were assayed. A whole genomic analysis was performed to identify key molecular alterations in FL sublines. Upon detachment on low-binding dishes, parental cells initially formed rounded spheroids with limited growth activity. However, over time in cultures, cells gradually formed smaller spheroids that grew slowly, and, after 3–4 months, we obtained FL sublines that regained prominent growth potential in suspension cultures. On ordinary dishes, FL cells reattached and exhibited a more spindle-shaped morphology than parental cells. No marked differences were observed in cell growth with attachment, migration, or invasion between FL sublines and parental cell lines; however, FL cells exhibited markedly increased growth potential under suspended conditions in vitro and stronger metastatic abilities in vivo. A genomic analysis identified epithelial-mesenchymal transition (EMT) and c-Myc amplification in A549-FL and H441-FL cells, respectively, as candidate mechanisms for metastasis. The growth potential of FL cells was markedly inhibited by lentiviral ZEB1 knockdown in A549-FL cells and by the inhibition of c-Myc through lentiviral knockdown or the pharmacological inhibitor JQ1 in H441-FL cells. Long-term three-dimensional low attachment cultures may become a useful method for investigating the mechanisms underlying metastasis mediated by decreased cell-substratum adhesion. PMID:28786996
Development of a Multi-Functional Biopolymer Scaffold for Neural Tissue Engineering
NASA Astrophysics Data System (ADS)
Francis, Nicola Louise
Spinal cord injury (SCI) affects approximately 270,000 people in the U.S., with approximately 12,000 new cases occurring every year. Several strategies have been investigated to enhance axonal regeneration after SCI, however, the resulting growth can be random and disorganized. Bioengineered scaffolds provide a physical substrate for the guidance of regenerating axons towards their targets, and can be produced by freeze casting. This technique involves the controlled directional solidification of an aqueous solution or suspension, resulting in a linearly aligned porous structure caused by ice templating. In this thesis, freeze casting was used to create novel porous chitosan-alginate (C/A) scaffolds with longitudinally aligned channels and a compressive modulus (5.08 ± 0.61 kPa) comparable to that of native spinal cord tissue. These C/A scaffolds supported the viability, attachment, and directionally oriented growth of chick dorsal root ganglia (DRG) neurites in vitro, with surface adsorptions of polycations and laminin promoting significantly longer neurite growth than the uncoated scaffolds (p<0.001). In order to integrate therapeutic biomolecules within the scaffolds for sustained release, alginate and chitosan microcapsules produced by spray drying were used to encapsulate brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3), and the enzyme chondroitinase ABC (chABC) prior to scaffold incorporation. BDNF and NT-3 were released from the C/A scaffolds in a sustained manner for 8 weeks in vitro, while chABC was released for up to 35 days. However, up to 85% of biomolecules emained entrapped within the scaffold walls, due to limitation of diffusion by the scaffold wall mesh size. Release of bioactive chABC and neurotrophins from the multifunctional scaffolds promoted the growth of DRG neurites through an in vitro barrier of chondroitin sulfate proteoglycans, a main inhibitory component of the growth-inhibiting glial scar in the injured spinal cord. The present data suggest these multi-functional scaffolds are suitable for use and future testing in vivo as a combination strategy for spinal cord repair due to their ability to promote the directionally oriented growth of neurites and their ability to provide the sustained release of therapeutic bioactive molecules for the stimulation of axonal growth through the glial scar.
The Politics of Attachment: Lines of Flight with Bowlby, Deleuze and Guattari
Duschinsky, Robbie; Greco, Monica; Solomon, Judith
2015-01-01
Research on attachment is widely regarded in sociology and feminist scholarship as politically conservative – oriented by a concern to police families, pathologize mothers and emphasize psychological at the expense of socio-economic factors. These critiques have presented attachment theory as constructing biological imperatives to naturalize contingent, social demands. We propose that a more effective critique of the politically conservative uses of attachment theory is offered by engaging with the ‘attachment system’ at the level of ontology. In developing this argument we draw on Deleuze and Guattari, making use of the common language of ethology which links their ideas to that of attachment theory. The attachment system can and has been reified into an image of the infant returning to their caregiver as an image of familial sufficiency. This has offered ammunition for discourses and institutions which isolate women from health, social and political resources. Yet Deleuze and Guattari can help attachment theory and research to be recognized as a powerful ally for progressive politics, for reflection on the movement of human individuation, and for arguing for the meaningful resourcing of those who care for someone else. PMID:27110049
The role of attachment in recovery after a school-shooting trauma.
Turunen, Tuija; Haravuori, Henna; Punamäki, Raija-Leena; Suomalainen, Laura; Marttunen, Mauri
2014-01-01
Survivors of life-endangering trauma use varying resources that help them to recover. Attachment system activates in the times of distress, and is expected to associate with stress responses, arousal regulation, and mental health. We examined the associations of attachment style with posttraumatic stress disorders (PTSD) symptoms and dissociative symptoms, and posttraumatic growth (PTG) among students exposed to a school shooting in Finland in a three-wave follow-up setting. Participants were students (M age=24.9 years; 95% female) who were followed 4 (T1, N=236), 16 (T2, N=180), and 28 months (T3, N=137) after the shooting. The assessments included the Attachment Style Questionnaire, the Impact of Event Scale, part of the Adolescent Dissociative Experiences Scale and the Posttraumatic Growth Inventory. Securely attached survivors had lower levels of posttraumatic stress and dissociative symptoms than preoccupied at T1 and T2 as hypothesized. At T3 survivors with avoidant attachment style had higher levels of intrusive and hyperarousal symptoms than those with secure style. Concerning PTG, survivors with avoidant attachment style scored lower in PTG at T3 than survivors with both secure and preoccupied style. Secure attachment style was beneficial in trauma recovery. A challenge to the health care systems is to acknowledge that survivors with preoccupied and avoidant attachment styles react uniquely to trauma, and thus need help in different doses, modalities, and timings.
McAuley, Catherine M.; Duffy, Lesley L.; Subasinghe, Nela; Hogg, Geoff; Coventry, John; Fegan, Narelle
2015-01-01
Salmonellosis in Australia has been linked to eggs and egg products with specific serotypes associated with outbreaks. We compared attachment to and survival on egg shells and growth in eggs of two Salmonella serotypes, an egg outbreak associated Salmonella Typhimurium and a non-egg-associated Salmonella enterica ssp. II 1,4,12,27:b:[e,n,x] (S. Sofia). Experiments were conducted at combinations of 4, 15, 22, 37 and 42°C. No significant differences occurred between the serotypes in maximum growth rates, which were significantly greater (P < 0.001) in egg yolk (0.427 log10 CFU/mL/h) compared to whole egg (0.312 log10 CFU/mL/h) and egg white (0.029 log10 CFU/mL/h). Attachment to egg shells varied by time (1 or 20 min) and temperature (4, 22 and 42°C), with S. Typhimurium isolates attaching at higher levels (P < 0.05) than S. Sofia after 1 min at 4°C and S. Typhimurium ATCC 14028 attaching at higher (P < 0.05) levels at 22°C. Survival on egg shells was not significantly different across isolates. Salmonella serotypes behaved similarly regarding growth in egg contents, attachment to egg shells and survival on eggs, indicating that other factors more likely contributed to reasons for S. Typhimurium being implicated in multiple egg-associated outbreaks. PMID:26539536
MicroRNA miR-30 family regulates non-attachment growth of breast cancer cells
2013-01-01
Background A subset of breast cancer cells displays increased ability to self-renew and reproduce breast cancer heterogeneity. The characterization of these so-called putative breast tumor-initiating cells (BT-ICs) may open the road for novel therapeutic strategies. As microRNAs (miRNAs) control developmental programs in stem cells, BT-ICs may also rely on specific miRNA profiles for their sustained activity. To explore the notion that miRNAs may have a role in sustaining BT-ICs, we performed a comprehensive profiling of miRNA expression in a model of putative BT-ICs enriched by non-attachment growth conditions. Results We found breast cancer cells grown under non-attachment conditions display a unique pattern of miRNA expression, highlighted by a marked low expression of miR-30 family members relative to parental cells. We further show that miR-30a regulates non-attachment growth. A target screening revealed that miR-30 family redundantly modulates the expression of apoptosis and proliferation-related genes. At least one of these targets, the anti-apoptotic protein AVEN, was able to partially revert the effect of miR-30a overexpression. Finally, overexpression of miR-30a in vivo was associated with reduced breast tumor progression. Conclusions miR30-family regulates the growth of breast cancer cells in non-attachment conditions. This is the first analysis of target prediction in a whole family of microRNAs potentially involved in survival of putative BT-ICs. PMID:23445407
Edge-Controlled Growth and Etching of Two-Dimensional GaSe Monolayers
Li, Xufan; Dong, Jichen; Idrobo, Juan C.; ...
2016-12-07
Understanding the atomistic mechanisms governing the growth of two-dimensional (2D) materials is of great importance in guiding the synthesis of wafer-sized, single-crystalline, high-quality 2D crystals and heterostructures. Etching, in many cases regarded as the reverse process of material growth, has been used to study the growth kinetics of graphene. In this paper, we explore a growth–etching–regrowth process of monolayer GaSe crystals, including single-crystalline triangles and irregularly shaped domains formed by merged triangles. We show that the etching begins at a slow rate, creating triangular, truncated triangular, or hexagonally shaped holes that eventually evolve to exclusively triangles that are rotated 60°more » with respect to the crystalline orientation of the monolayer triangular crystals. The regrowth occurs much faster than etching, reversibly filling the etched holes and then enlarging the size of the monolayer crystals. A theoretical model developed based on kinetic Wulff construction (KWC) theory and density functional theory (DFT) calculations accurately describe the observed morphology evolution of the monolayer GaSe crystals and etched holes during the growth and etching processes, showing that they are governed by the probability of atom attachment/detachment to/from different types of edges with different formation energies of nucleus/dents mediated by chemical potential difference Δμ between Ga and Se. Finally, our growth–etching–regrowth study provides not only guidance to understand the growth mechanisms of 2D binary crystals but also a potential method for the synthesis of large, shape-controllable, high-quality single-crystalline 2D crystals and their lateral heterostructures.« less
Ferràndez-Cañadell, Carles; Briguglio, Antonino; Hohenegger, Johann; Wöger, Julia
2015-01-01
In foraminifera, so-called “double tests” usually arise due to abnormal growth originating mainly from twinning, but may also be caused by irregularities in the early chambers and by regeneration after test injury that modifies the direction of growth. A fourth cause of double tests has only rarely been reported: the fusion of the tests of two adult individuals. We studied an early Eocene Nummulites double test consisting of two adult individuals that fused after an extended period of independent growth. The specimen was studied using computed tomography with micrometric resolution (micro-CT) that allowed bi- and three-dimensional visualization of the internal structure. Before fusion each individual test had 30–36 chambers, which, by comparison with growth rates in recent nummulitids, implies at least three months of independent growth. After fusion, the compound test grew in two spirals that fused after about one whorl and then continued in a single spiral. To fuse their tests, either adult individuals have to be forced to do so or the allorecognition (ability to distinguish between self and another individual) mechanisms must fail. A possible explanation for the merged Nummulites tests in this study is forced fusion in attached individuals after surviving ingestion and digestion by a metazoan. Alternatively, environmental stress could lead to a failure of allorecognition mechanisms and/or foraminiferal motility. Once fused, subsequent growth seems to be determined mainly by the relative orientation of individual tests. In any case, the frequency in which adult fusion occurs remains unknown. PMID:26166916
Improved attachment of mesenchymal stem cells on super-hydrophobic TiO2 nanotubes.
Bauer, Sebastian; Park, Jung; von der Mark, Klaus; Schmuki, Patrik
2008-09-01
Self-organized layers of vertically orientated TiO(2) nanotubes providing defined diameters ranging from 15 up to 100nm were grown on titanium by anodic oxidation. These TiO(2) nanotube layers show super-hydrophilic behavior. After coating TiO(2) nanotube layers with a self-assembled monolayer (octadecylphosphonic acid) they showed a diameter-dependent wetting behavior ranging from hydrophobic (108+/-2 degrees ) up to super-hydrophobic (167+/-2 degrees ). Cell adhesion, spreading and growth of mesenchymal stem cells on the unmodified and modified nanotube layers were investigated and compared. We show that cell adhesion and proliferation are strongly affected in the super-hydrophobic range. Adsorption of extracellular matrix proteins as fibronectin, type I collagen and laminin, as well as bovine serum albumin, on the coated and uncoated surfaces showed a strong influence on wetting behavior and dependence on tube diameter.
Zhao, Haidong; Liu, Rui; Guo, Yong; Yang, Shengchun
2015-12-14
In the current research, the PtxAgy (x/y = 86/14, 79/21, 52/48, 21/79, 11/89) nanoparticles (NPs) are synthesized in the KNO3-LiNO3 molten salts without using any organic surfactant or solvent. The SEM results suggest that when the content of Ag is higher than 48%, the wormlike PtxAgy nanotubes (NTs) can be synthesized. The diameter of the PtxAgyNTs shows a slow decrease with the increase of Ag content. The TEM and HRTEM results indicate that the growth of hollow PtxAgy NTs undergoes an oriented attachment process and a Kirkendall effect approach. The results of cyclic voltammetry (CV) measurement indicate that the Pt52Ag48 catalyst presents a remarkable enhancement for methanol electrooxidation, while the Pt86Ag14 catalyst prefers electrochemically oxidizing formic acid compared with that of the commercially available Pt black.
Bioengineering single crystal growth.
Wu, Ching-Hsuan; Park, Alexander; Joester, Derk
2011-02-16
Biomineralization is a "bottom-up" synthesis process that results in the formation of inorganic/organic nanocomposites with unrivaled control over structure, superior mechanical properties, adaptive response, and the capability of self-repair. While de novo design of such highly optimized materials may still be out of reach, engineering of the biosynthetic machinery may offer an alternative route to design advanced materials. Herein, we present an approach using micro-contact-printed lectins for patterning sea urchin embryo primary mesenchyme cells (PMCs) in vitro. We demonstrate not only that PMCs cultured on these substrates show attachment to wheat germ agglutinin and concanavalin A patterns but, more importantly, that the deposition and elongation of calcite spicules occurs cooperatively by multiple cells and in alignment with the printed pattern. This allows us to control the placement and orientation of smooth, cylindrical calcite single crystals where the crystallographic c-direction is parallel to the cylinder axis and the underlying line pattern.
Berrang, Mark E; Hofacre, Charles L; Frank, Joseph F
2014-12-01
Listeria monocytogenes can colonize a poultry processing plant as a resident in floor drains. Limiting growth and attachment to drain surfaces may help lessen the potential for cross-contamination of product. The objective of this study was to compare a hydrogen peroxide-peroxyacetic acid-based chemical to chitosan-arginine or heat to prevent attachment of or destroy existing L. monocytogenes on the inner surface of model floor drains. L. monocytogenes was introduced to result in about 10(9) planktonic and attached cells within untreated polyvinyl chloride model drain pipes. Treatments (0.13 % peroxide-based sanitizer, 0.1 % chitosan-arginine, or 15 s of hot water at 95 to 100°C) were applied immediately after inoculation or after 24 h of incubation. Following treatment, all pipes were incubated for an additional 24 h; planktonic and attached cells were enumerated by plate count. All treatments significantly (P < 0.05) lowered numbers of planktonic and attached cells recovered. Chitosan-arginine resulted in approximately a 6-log reduction in planktonic cells when applied prior to incubation and a 3-log reduction after the inoculum had a chance to grow. Both heat and peroxide significantly outperformed chitosan-arginine (8- to 9-log reduction) and were equally effective before and after incubation. Heat was the only treatment that eliminated planktonic L. monocytogenes. All treatments were less effective against attached cells. Chitosan-arginine provided about a 4.5-log decrease in attached cells when applied before incubation and no significant decrease when applied after growth. Like with planktonic cells, peroxide-peroxyacetic acid and heat were equally effective before or after incubation, causing decreases ranging from 7 to 8.5 log for attached L. monocytogenes. Applied at the most efficacious time, any of these techniques may lessen the potential for L. monocytogenes to remain as a long-term resident in processing plant floor drains.
“Ins” and “Outs” of mesenchymal stem cell osteogenesis in regenerative medicine
Yamaguchi, Dean T
2014-01-01
Repair and regeneration of bone requires mesenchymal stem cells that by self-renewal, are able to generate a critical mass of cells with the ability to differentiate into osteoblasts that can produce bone protein matrix (osteoid) and enable its mineralization. The number of human mesenchymal stem cells (hMSCs) diminishes with age and ex vivo replication of hMSCs has limited potential. While propagating hMSCs under hypoxic conditions may maintain their ability to self-renew, the strategy of using human telomerase reverse transcriptase (hTERT) to allow for hMSCs to prolong their replicative lifespan is an attractive means of ensuring a critical mass of cells with the potential to differentiate into various mesodermal structural tissues including bone. However, this strategy must be tempered by the oncogenic potential of TERT-transformed cells, or their ability to enhance already established cancers, the unknown differentiating potential of high population doubling hMSCs and the source of hMSCs (e.g., bone marrow, adipose-derived, muscle-derived, umbilical cord blood, etc.) that may provide peculiarities to self-renewal, differentiation, and physiologic function that may differ from non-transformed native cells. Tissue engineering approaches to use hMSCs to repair bone defects utilize the growth of hMSCs on three-dimensional scaffolds that can either be a base on which hMSCs can attach and grow or as a means of sequestering growth factors to assist in the chemoattraction and differentiation of native hMSCs. The use of whole native extracellular matrix (ECM) produced by hMSCs, rather than individual ECM components, appear to be advantageous in not only being utilized as a three-dimensional attachment base but also in appropriate orientation of cells and their differentiation through the growth factors that native ECM harbor or in simulating growth factor motifs. The origin of native ECM, whether from hMSCs from young or old individuals is a critical factor in “rejuvenating” hMSCs from older individuals grown on ECM from younger individuals. PMID:24772237
Attachment in young children with incarcerated fathers.
Poehlmann-Tynan, Julie; Burnson, Cynthia; Runion, Hilary; Weymouth, Lindsay A
2017-05-01
The present study examined young children's attachment behaviors during paternal incarceration and reported on initial validity of a new measure used to rate children's attachment-related behaviors and emotions during visits in a corrections setting. Seventy-seven children, age 2 to 6 years, and their jailed fathers and current caregivers participated in the home visit portion of the study, whereas 28 of these children participated in the jail visit. The results indicated that 27% of children witnessed the father's crime and 22% of children witnessed the father's arrest, with most children who witnessed these events exhibiting extreme distress; children who witnessed these events were more likely to have insecure attachments to their caregivers. Consistent with attachment theory and research, caregivers who exhibited more sensitivity and responsivity during interactions with children and those who provided more stimulating, responsive, learning-oriented home environments had children who were more likely to have secure attachments (measured with the Attachment Q-Sort). We also found preliminary evidence for the validity of our new measure, the Jail Prison Observation Checklist, in that children's attachment-related behaviors and emotions during the jail visit correlated with their attachment security observed in the home. Our observations indicate that, in certain contexts, noncontact visits with incarcerated parents can be stressful for children and that children's caregivers may play a significant role during these visits.
Schmitt, Elizabeth Dunne
2008-01-01
Several studies examine the link between sexual orientation and earnings using large data sets that distinguish sexual orientation through questions about sexual behavior and/or by allowing respondents to self-identify as part of a same-sex cohabitating couple. After controlling for other earnings-related characteristics these studies generally show an earnings penalty for gay/bisexual men relative to heterosexual men and an earnings premium for lesbian/bisexual women relative to heterosexual women. Explanations for this gender disparity include gender differences in sexual orientation discrimination, greater labor force attachment for lesbian/bisexual women, and the effects of the overall gender earnings gap.
Scott, Charles D.; Hancher, Charles W.
1977-01-01
A vertically oriented conically shaped column is used as a fluidized bed bioreactor wherein biologically catalyzed reactions are conducted in a continuous manner. The column utilizes a packing material a support having attached thereto a biologically active catalytic material.
Understanding the Role of Solvation Forces on the Preferential Attachment of Nanoparticles in Liquid
Welch, David A.; Woehl, Taylor J.; Park, Chiwoo; ...
2015-11-20
We discuss optimization of colloidal nanoparticle synthesis techniques, which requires an understanding of underlying particle growth mechanisms. Nonclassical growth mechanisms are particularly important as they affect nanoparticle size and shape distributions, which in turn influence functional properties. For example, preferential attachment of nanoparticles is known to lead to the formation of mesocrystals, although the formation mechanism is currently not well-understood. Here we employ in situ liquid cell scanning transmission electron microscopy and steered molecular dynamics (SMD) simulations to demonstrate that the experimentally observed preference for end-to-end attachment of silver nanorods is a result of weaker solvation forces occurring at rodmore » ends. In conclusion, SMD reveals that when the side of a nanorod approaches another rod, perturbation in the surface-bound water at the nanorod surface creates significant energy barriers to attachment. Additionally, rod morphology (i.e., facet shape) effects can explain the majority of the side attachment effects that are observed experimentally.« less
Understanding the Role of Solvation Forces on the Preferential Attachment of Nanoparticles in Liquid
DOE Office of Scientific and Technical Information (OSTI.GOV)
Welch, David A.; Woehl, Taylor J.; Park, Chiwoo
We discuss optimization of colloidal nanoparticle synthesis techniques, which requires an understanding of underlying particle growth mechanisms. Nonclassical growth mechanisms are particularly important as they affect nanoparticle size and shape distributions, which in turn influence functional properties. For example, preferential attachment of nanoparticles is known to lead to the formation of mesocrystals, although the formation mechanism is currently not well-understood. Here we employ in situ liquid cell scanning transmission electron microscopy and steered molecular dynamics (SMD) simulations to demonstrate that the experimentally observed preference for end-to-end attachment of silver nanorods is a result of weaker solvation forces occurring at rodmore » ends. In conclusion, SMD reveals that when the side of a nanorod approaches another rod, perturbation in the surface-bound water at the nanorod surface creates significant energy barriers to attachment. Additionally, rod morphology (i.e., facet shape) effects can explain the majority of the side attachment effects that are observed experimentally.« less
Understanding the Role of Solvation Forces on the Preferential Attachment of Nanoparticles in Liquid
DOE Office of Scientific and Technical Information (OSTI.GOV)
Welch, David A.; Woehl, Taylor J.; Park, Chiwoo
Optimization of colloidal nanoparticle synthesis techniques requires an understanding of underlying particle growth mechanisms. Non-classical growth mechanisms are particularly important as they affect nanoparticle size and shape distributions which in turn influence functional properties. For example, preferential attachment of nanoparticles is known to lead to the formation of mesocrystals, although the formation mechanism is currently not well understood. Here we employ in situ liquid cell scanning transmission electron microscopy (STEM) and steered molecular dynamics (SMD) simulations to demonstrate that the experimentally observed preference for end-to-end attachment of silver nanorods is a result of weaker solvation forces occurring at rod ends.more » SMD reveals that when the side of a nanorod approaches another rod, perturbation in the surface bound water at the nanorod surface creates significant energy barriers to attachment. Additionally, rod morphology (i.e. facet shape) effects can explain the majority of the side attachment effects that are observed experimentally.« less
Cameron, Catherine Ann; Ungar, Michael; Liebenberg, Linda
2007-04-01
The authors examine one of the precursors of positive development: attachment. Attachment and the positive growth it portends for populations of children under stress underpins positive developmental outcomes now termed "resilience." Resilience may be understood as a process of adaptation to adversity that is scaffolded by environmental, cultural, social, psychologic, and physiologic processes. The authors focus on two methodologically different approaches to studying attachments that contribute to resilient functioning at two different phases of development (toddlerhood and adolescence). The authors examine the cultural differences found in manifestations of resilience in different countries and cultures. Organized around this theme of attachment, the authors identify adaptive factors in resistance to risk from adverse circumstances. The authors strive to identify how the adaptation involved in attachment relations can protect against vulnerability. The authors conclude with a description of the processes that might help us to understand situational, experiential, and personal resources that intersect to protect the developing individual against assaults on normal growth and development.
Probing the Pathways and Interactions Controlling Crystallization by Particle Attachment
NASA Astrophysics Data System (ADS)
De Yoreo, J. J.; Li, D.; Chun, J.; Schenter, G.; Mundy, C.; Rosso, K. M.
2016-12-01
Crystallization by particle attachment appears to be a widespread mechanism of mineralization. Yet many long-standing questions surrounding nucleation and assembly of precursor particles remain unanswered, due in part to a lack of tools to probe mineralization dynamics with adequate spatial and temporal resolution. Here we report results of liquid phase TEM studies of nucleation and particle assembly in a number of mineral systems. We interpret the results within a framework that considers the impact of both the complexity of free energy landscapes and kinetic factors associated with high supersaturation or slow dynamics. In the calcium carbonate system, the need for high supersturations to overcome the high barrier to nucleation of calcite leads to simultaneous occurrence of multiple pathways, including direct formation of all the common ploymorphs, as well as two-step pathways through which initial precursors, particularly ACC, undergo a direct transformation to a more stable phase. Introduction of highly charged polymers that bind calcium inhibits nucleation, but directs the pathway to a metastable amorphous phase that no longer transforms to more stable polymorphs. Experiments in the iron oxide and oxyhydroxide systems show that, when high supersaturations lead to nucleation of many nanoprticles, further growth occurs through a combination of particle aggregation events and Ostwald ripening. In some cases, aggregation occurs only through oriented attachment on lattice matched faces, leading to single crystals with complex topologies and internal twin boundaries, while in others aggregation results initially in poor co-alignment, but over time the particles undergo atomic rearrangements to achieve a single crystal structure. AFM-based measurements of forces between phyllosilicate surfaces reveal the importance of long-range dispersion interactions in driving alignment, as well as the impact of electrolyte concentration and temperature on the competition of those attractive forces with repulsive electrostatic interactions. Taken together, the results help to define an emerging framework for understanding crystallization by particle attachment.
Role of surface properties in bacterial attachment
NASA Astrophysics Data System (ADS)
Conrad, Jacinta; Sharma, Sumedha
2014-03-01
Bacterial biofilms foul a wide range of engineered surfaces, from pipelines to membranes to biomedical implants, and lead to deleterious costs for industry and for human health. Designing strategies to reduce bacterial fouling requires fundamental understanding of mechanisms by which bacteria attach to surfaces. We investigate the attachment of Escherichia coli on silanized glass surfaces during flow through a linear channel at flow rates of 0.1-1 mL/min using confocal microscopy. We deposit self-assembled monolayers of organosilanes on glass and track the position and orientation of bacteria deposited on these surfaces during flow using high-throughput image processing algorithms. Here, we report differences in deposition rate and surface-tethered motion of cells as a function of surface charge and surface energy, suggesting that attachment of bacteria on these engineered surfaces is dominated by different physical mechanisms.
NASA Astrophysics Data System (ADS)
Ma, Ji; Chen, Kezheng
2016-05-01
In this study, room-temperature spin-glass behaviors were observed in flake-like oriented attached hematite (α-Fe2O3) and iron phosphate hydroxide hydrate (Fe5(PO4)4(OH)3·2H2O) single crystals. Remarkably, their coercivity (HC) values were found to be almost invariable at various given temperatures from 5 to 300 K. The spin topographic map in these flakes was assumed as superparamagnetic (SPM) "islands" isolated by spin glass (SG)-like "bridges". A spin-glass model was then proposed to demonstrate the spin frustration within these "bridges", which were formed by the staggered atomic planes in the uneven surfaces belonging to different attached nanoparticles. Under the spatial limitation and coupling shield of these "bridges", the SPM "islands" were found to be collectively frozen to form a superspin glass (SSG) state below 80 K in weak applied magnetic fields; whereas, when strong magnetic fields were applied, the magnetic coupling of these "islands" would become superferromagnetic (SFM) through tunneling superexchange, so that, these SFM spins could antiferromagnetically couple with the SG-like "bridges" to yield pronounced exchange bias (EB) effect.
Grounding the figure: surface attachment influences figure-ground organization.
Vecera, Shaun P; Palmer, Stephen E
2006-08-01
We investigated whether the lower region effect on figure-ground organization (Vecera, Vogel, and Woodman, 2002) would generalize to contextual depth planes in vertical orientations, as is predicted by a theoretical analysis based on the ecological statistics of edges arising from objects that are attached to surfaces of support. Observers viewed left/right ambiguous figure-ground displays that occluded middle sections of four types of contextual inducers: two types of attached, receding, vertical planes (walls) that used linear perspective and/or texture gradients to induce perceived depth and two types of similar trapezoidal control figures that used either uniform color or random texture to reduce or eliminate perceived depth. The results showed a reliable bias toward seeing as "figure" the side of the figure-ground display that was attached to the receding depth plane, but no such bias for the corresponding side in either of the control conditions. The results are interpreted as being consistent with the attachment hypothesis that the lower region cue to figure-ground organization results from ecological biases in edge interpretation that arise when objects are attached to supporting surfaces in the terrestrial gravitational field.
The role of attachment in recovery after a school-shooting trauma
Turunen, Tuija; Haravuori, Henna; Punamäki, Raija-Leena; Suomalainen, Laura; Marttunen, Mauri
2014-01-01
Background Survivors of life-endangering trauma use varying resources that help them to recover. Attachment system activates in the times of distress, and is expected to associate with stress responses, arousal regulation, and mental health. Objective We examined the associations of attachment style with posttraumatic stress disorders (PTSD) symptoms and dissociative symptoms, and posttraumatic growth (PTG) among students exposed to a school shooting in Finland in a three-wave follow-up setting. Method Participants were students (Mage=24.9 years; 95% female) who were followed 4 (T1, N=236), 16 (T2, N=180), and 28 months (T3, N=137) after the shooting. The assessments included the Attachment Style Questionnaire, the Impact of Event Scale, part of the Adolescent Dissociative Experiences Scale and the Posttraumatic Growth Inventory. Results Securely attached survivors had lower levels of posttraumatic stress and dissociative symptoms than preoccupied at T1 and T2 as hypothesized. At T3 survivors with avoidant attachment style had higher levels of intrusive and hyperarousal symptoms than those with secure style. Concerning PTG, survivors with avoidant attachment style scored lower in PTG at T3 than survivors with both secure and preoccupied style. Conclusion Secure attachment style was beneficial in trauma recovery. A challenge to the health care systems is to acknowledge that survivors with preoccupied and avoidant attachment styles react uniquely to trauma, and thus need help in different doses, modalities, and timings. PMID:25018861
NASA Technical Reports Server (NTRS)
Seidel-Salinas, L. K.; Jones, S. H.; Duva, J. M.
1992-01-01
A semi-empirical model has been developed to determine the complete crystallographic orientation dependence of the growth rate for vapor phase epitaxy (VPE). Previous researchers have been able to determine this dependence for a limited range of orientations; however, our model yields relative growth rate information for any orientation. This model for diamond and zincblende structure materials is based on experimental growth rate data, gas phase diffusion, and surface reactions. Data for GaAs chloride VPE is used to illustrate the model. The resulting growth rate polar diagrams are used in conjunction with Wulff constructions to simulate epitaxial layer shapes as grown on patterned substrates. In general, this model can be applied to a variety of materials and vapor phase epitaxy systems.
Final results of the NASA storm hazards program
NASA Technical Reports Server (NTRS)
Fisher, Bruce D.; Brown, Philip W.; Plumer, J. Anderson; Wunschel, Alfred J., Jr.
1988-01-01
Lightning swept-flash attachment patterns and the associated flight conditions were recorded from 1980-1986 during 1496 thunderstorm penetrations and 714 direct strikes with a NASA F-1068 research airplane. These data were studied with an emphasis on lightning avoidance by aircraft and on aircraft protection design. The individual lightning attachment spots, along with crew comments and on-board photographic data were used to identify lightning swept-flash attachment patterns and the orientations of the lightning channels with respect to the airplane. The full-scale in-flight data were compared to results from scale-model arc-attachment tests. The airborne and scale-model data showed that any exterior surface of this airplane may be susceptible to direct lightning attachment. In addition, the altitudes, ambient temperatures, and the relative turbulence and precipitation levels at which the strikes occurred in thunderstorms are summarized and discussed. It was found that the peak strike rate occurred at pressure altitudes betwen 38,000 ft and 40,000 ft, corresponding to ambient temperatures colder than -40 C.
Lee, Lauren A.; Sbarra, David A.; Mason, Ashley E.; Law, Rita W.
2011-01-01
Marital separation and divorce increase risk for all-cause morbidity and mortality. Using a laboratory analogue paradigm, the present study examined attachment anxiety, language use, and blood pressure (BP) reactivity among 119 (n = 43 men, 76 women) recently separated adults who were asked to mentally reflect on their relationship history and separation experience. We created a language use composite of verbal immediacy from participants’ stream-of-consciousness recordings about their separation experience as a behavioral index of attachment-related hyperactivation. Verbal immediacy moderated the association between attachment anxiety and BP at the beginning of a divorce-specific activation task. Participants reporting high attachment anxiety who discussed their separation in a first-person, present-oriented and highly engaged manner evidenced the highest levels of BP at the start of the divorce-specific task. Results provide a deeper understanding of the association between marital dissolution and health and suggest that verbal immediacy may be a useful behavioral index of hyperactivating coping strategies. PMID:21647240
Lee, Lauren A; Sbarra, David A; Mason, Ashley E; Law, Rita W
2011-06-01
Marital separation and divorce increase risk for all-cause morbidity and mortality. Using a laboratory analogue paradigm, the present study examined attachment anxiety, language use, and blood pressure (BP) reactivity among 119 (n = 43 men, 76 women) recently separated adults who were asked to mentally reflect on their relationship history and separation experience. We created a language use composite of verbal immediacy from participants' stream-of-consciousness recordings about their separation experience as a behavioral index of attachment-related hyperactivation. Verbal immediacy moderated the association between attachment anxiety and BP at the beginning of a divorce-specific activation task. Participants reporting high attachment anxiety who discussed their separation in a first-person, present-oriented and highly engaged manner evidenced the highest levels of BP at the start of the divorce-specific task. Results provide a deeper understanding of the association between marital dissolution and health and suggest that verbal immediacy may be a useful behavioral index of hyperactivating coping strategies.
Microcoupon Assay Of Adhesion And Growth Of Bacterial Films
NASA Technical Reports Server (NTRS)
Pierson, Duane L.; Koenig, David W.
1994-01-01
Microbiological assay technique facilitates determination of some characteristics of sessile bacteria like those that attach to and coat interior walls of water-purification systems. Biofilms cause sickness and interfere with purification process. Technique enables direct measurement of rate of attachment of bacterial cells, their metabolism, and effects of chemicals on them. Used to quantify effects of both bactericides and growth-stimulating agents and in place of older standard plate-count and tube-dilution techniques.
Lin, Hsin-Yi; Peng, Zhao-Xiang
2017-08-17
The surface of medical implant alloy Ti-6Al-4V was chemically modified to allow it to covalently bond with collagen/PVA nanofibers. These nanofibers were successfully attached to the Ti-6Al-4V surface in three different morphologies: randomly oriented high-density fiber, COL(H); randomly oriented low-density fiber, COL(L); and aligned high-density fiber, COL(A). The effects of the morphology of these covalently-bound collagen nanofibers on the growth and differentiation of osteoblasts were studied for 21 days. The low-density nanofibers covered approximately 80% of the Ti64 surface, while the high-density nanofibers covered nearly 100%. These covalently attached fibrous coatings remained attached to the metal surface after 3 weeks of cell culture. In the first week the aligned fibers of COL(A) allowed the osteoblasts to stretch and elongate in the direction of the fibers. This directional elongation was not seen in the cells on the randomly-oriented samples. Cells proliferated and differentiated on all three surfaces over time. By the end of the test, the amount of type I collagen secreted by the cells on COL(H) was the highest, while the degree of mineralization was highest on COL(A) among the three samples (p < 0.05). Different nanofiber morphologies changed the cell morphology and the secretion of cellular products. The mechanisms remained to be investigated. The surface of medical implant alloy Ti-6Al-4V was chemically modified to allow it to covalently bond with collagen/PVA nanofibers. The SEM micrographs in the top row show the random and aligned morphology of the collagen-PVA nanofibers. The nanofibers on COL(A) were aligned in the general direction indicated by the arrow. The second row are images from EDX titanium element mapping. The location of the titanium elements are shown as bright dots. The low-density nanofibers, COL(L), covered approximately 80% of the Ti64 surface, while the high-density nanofibers, COL(H) and COL(A), covered nearly 100%. All three surfaces demonstrated good biocompatibility for the cultured osteoblasts. The fiber alignment seemed to have an effect on early cellular morphology (day 7), collagen secretion and calcium deposition, while the density of the fibers seemed to have no significant effect on cell behavior. SEM micrographs of osteoblasts after 7 and 14 days of cell culture are shown in the third and fourth rows. The surface of COL(L) has more cell-free spots indicated by (*) on day 7 as other two surfaces were covered by cells. The nanofibers could no longer be observed and were covered with mineralized granules (circles) after 14 days of cell culture. The cells appear stretched out on the mineralized granules.
Large-scale fabrication of vertically aligned ZnO nanowire arrays
Wang, Zhong L; Das, Suman; Xu, Sheng; Yuan, Dajun; Guo, Rui; Wei, Yaguang; Wu, Wenzhuo
2013-02-05
In a method for growing a nanowire array, a photoresist layer is placed onto a nanowire growth layer configured for growing nanowires therefrom. The photoresist layer is exposed to a coherent light interference pattern that includes periodically alternately spaced dark bands and light bands along a first orientation. The photoresist layer exposed to the coherent light interference pattern along a second orientation, transverse to the first orientation. The photoresist layer developed so as to remove photoresist from areas corresponding to areas of intersection of the dark bands of the interference pattern along the first orientation and the dark bands of the interference pattern along the second orientation, thereby leaving an ordered array of holes passing through the photoresist layer. The photoresist layer and the nanowire growth layer are placed into a nanowire growth environment, thereby growing nanowires from the nanowire growth layer through the array of holes.
1980-01-01
Prometaphase in two large species of diatoms is examined, using the following techniques: (a) time-lapse cinematography of chromosome movements in vivo; (b) electron microscopy of corresponding stages: (c) reconstruction of the microtubules (MTs) in the kinetochore fiber of chromosomes attached to the spindle. In vivo, the chromosomes independently commence oscillations back and forth to one pole. The kinetochore is usually at the leading edge of such chromosome movements; a variable time later both kinetochores undergo such oscillations but toward opposite poles and soon stretch poleward to establish stable bipolar attachment. Electron microscopy of early prometaphase shows that the kinetochores usually laterally associate with MTs that have one end attached to the spindle pole. At late prometaphase, most chromosomes are fully attached to the spindle, but the kinetochores on unattached chromosomes are bare of MTs. Reconstruction of the kinetochore fiber demonstrates that most of its MTs (96%) extend past the kinetochore and are thus apparently not nucleated there. At least one MT terminates at each kinetochore analyzed. Our interpretation is that the conventional view of kinetochore function cannot apply to diatoms. The kinetochore fiber in diatoms appears to be primarily composed of MTs from the poles, in contrast to the conventional view that many MTs of the kinetochore fiber are nucleated by the kinetochore. Similarly, chromosomes appear to initially orient their kinetochores to opposite poles by moving along MTs attached to the poles, instead of orientation effected by kinetochore MTs laterally associating with other MTs in the spindle. The function of the kinetochore in diatoms and other cell types is discussed. PMID:7400213
Energy-driven surface evolution in beta-MnO2 structures
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yao, Wentao; Yuan, Yifei; Asayesh-Ardakani, Hasti
Exposed crystal facets directly affect the electrochemical/catalytic performance of MnO2 materials during their applications in supercapacitors, rechargeable batteries, and fuel cells. Currently, the facet-controlled synthesis of MnO2 is facing serious challenges due to the lack of an in-depth understanding of their surface evolution mechanisms. Here, combining aberration-corrected scanning transmission electron microscopy (STEM) and high-resolution TEM, we revealed a mutual energy-driven mechanism between beta-MnO2 nanowires and microstructures that dominated the evolution of the lateral facets in both structures. The evolution of the lateral surfaces followed the elimination of the {100} facets and increased the occupancy of {110} facets with the increasemore » in hydrothermal retention time. Both self-growth and oriented attachment along their {100} facets were observed as two different ways to reduce the surface energies of the beta-MnO2 structures. High-density screw dislocations with the 1/2 < 100 > Burgers vector were generated consequently. The observed surface evolution phenomenon offers guidance for the facet-controlled growth of beta-MnO2 materials with high performances for its application in metal-air batteries, fuel cells, supercapacitors, etc.« less
Two-dimensional inorganic-organic perovskite hexagonal nanosheets: growth and mechanism
NASA Astrophysics Data System (ADS)
Shakya, Suman; Prakash, G. Vijaya
2015-03-01
In this era of novel technological materials, inorganic-organic (IO) materials has emerged as new class of materials for their application in photonic materials, miniaturized sensors, optoelectronic devices, non-linear optical apparatus by exploiting the properties of both constituents in a single entity. Here we present the formation and growth mechanism of two dimensional Inorganic-organic (IO) perovskite structures from anisotropically grown PbO hexagonal nanosheets, in three steps: Fabrication of hexagonal PbO nanosheets by the versatile bottom-up electrochemical deposition technique, iodinization of PbO into PbI2, followed by conversion of PbI2 into IO hybrid by the intercalation of organic moiety. A systematic and detailed structural study reveals that PbO nanosheet formation is more likely to result from an oriented attachment mechanism, in which the sheets formed by the reduction in surface area that happens during aggregation of small nanoparticle that each has a net dipole moment, which tends to form a self-assembled structure. Intercalation of organic moiety into the PbI2 layers yielded a selfassembled quantum-wells system of one of the IO hybrid, i.e. (C6H9C2H4NH3)2PbI4 (CHPI), sustaining the hexagonal shape.
Xia, Xinhui; Tu, Jiangping; Zhang, Yongqi; Wang, Xiuli; Gu, Changdong; Zhao, Xin-Bing; Fan, Hong Jin
2012-06-26
The high performance of a pseudocapacitor electrode relies largely on a scrupulous design of nanoarchitectures and smart hybridization of bespoke active materials. We present a powerful two-step solution-based method for the fabrication of transition metal oxide core/shell nanostructure arrays on various conductive substrates. Demonstrated examples include Co(3)O(4) or ZnO nanowire core and NiO nanoflake shells with a hierarchical and porous morphology. The "oriented attachment" and "self-assembly" crystal growth mechanisms are proposed to explain the formation of the NiO nanoflake shell. Supercapacitor electrodes based on the Co(3)O(4)/NiO nanowire arrays on 3D macroporous nickel foam are thoroughly characterized. The electrodes exhibit a high specific capacitance of 853 F/g at 2 A/g after 6000 cycles and an excellent cycling stability, owing to the unique porous core/shell nanowire array architecture, and a rational combination of two electrochemically active materials. Our growth approach offers a new technique for the design and synthesis of transition metal oxide or hydroxide hierarchical nanoarrays that are promising for electrochemical energy storage, catalysis, and gas sensing applications.
Long-wave model for strongly anisotropic growth of a crystal step.
Khenner, Mikhail
2013-08-01
A continuum model for the dynamics of a single step with the strongly anisotropic line energy is formulated and analyzed. The step grows by attachment of adatoms from the lower terrace, onto which atoms adsorb from a vapor phase or from a molecular beam, and the desorption is nonnegligible (the "one-sided" model). Via a multiscale expansion, we derived a long-wave, strongly nonlinear, and strongly anisotropic evolution PDE for the step profile. Written in terms of the step slope, the PDE can be represented in a form similar to a convective Cahn-Hilliard equation. We performed the linear stability analysis and computed the nonlinear dynamics. Linear stability depends on whether the stiffness is minimum or maximum in the direction of the step growth. It also depends nontrivially on the combination of the anisotropy strength parameter and the atomic flux from the terrace to the step. Computations show formation and coarsening of a hill-and-valley structure superimposed onto a long-wavelength profile, which independently coarsens. Coarsening laws for the hill-and-valley structure are computed for two principal orientations of a maximum step stiffness, the increasing anisotropy strength, and the varying atomic flux.
Two-stage epitaxial growth of vertically-aligned SnO 2 nano-rods on(001) ceria
Solovyov, Vyacheslav F.; Wu, Li-jun; Rupich, Martin W.; ...
2014-09-20
Growth of high-aspect ratio oriented tin oxide, SnO 2, nano-rods is complicated by a limited choice of matching substrates. We show that a (001) cerium oxide, CeO 2, surface uniquely enables epitaxial growth of tin-oxide nano-rods via a two-stage process. First, (100) oriented nano-wires coat the ceria surface by lateral growth, forming a uniaxially-textured SnO 2 deposit. Second, vertical SnO 2nano-rods nucleate on the deposit by homoepitaxy. We demonstrate growth of vertically oriented 1-2 μm long nano-rods with an average diameter of ≈20 nm.
2011-01-01
A simple method for the synthesis of ZnO nanofilms composed of vertical array of quasi-1D ZnO nanostructures (quasi-NRs) on the surface was demonstrated via a 1D crystal growth of the attached nanoseeds under a rapid hydrolysis process of zinc salts in the presence of ammonia at room temperature. In a typical procedure, by simply controlling the concentration of zinc acetate and ammonia in the reaction, a high density of vertically oriented nanorod-like morphology could be successfully obtained in a relatively short growth period (approximately 4 to 5 min) and at a room-temperature process. The average diameter and the length of the nanostructures are approximately 30 and 110 nm, respectively. The as-prepared quasi-NRs products were pure ZnO phase in nature without the presence of any zinc complexes as confirmed by the XRD characterisation. Room-temperature optical absorption spectroscopy exhibits the presence of two separate excitonic characters inferring that the as-prepared ZnO quasi-NRs are high-crystallinity properties in nature. The mechanism of growth for the ZnO quasi-NRs will be proposed. Due to their simplicity, the method should become a potential alternative for a rapid and cost-effective preparation of high-quality ZnO quasi-NRs nanofilms for use in photovoltaic or photocatalytics applications. PACS: 81.07.Bc; 81.16.-c; 81.07.Gf. PMID:22027275
Ho, S. Shaun; Swain, James E.
2017-01-01
Maternal attachment-related parenting behaviors require mothers to regulate self-related and child-related distress. Emotion regulation is, in turn, influenced by maternal mood and personal developmental history. In the current study we examined how depressive mood may alter maternal limbic system function and functional connectivity underlying defensive and hedonic motivations. Twenty nine mothers were recruited to undergo a baby-cry task during a functional magnetic resonance imaging (fMRI) scan. Based on self-reported depression symptoms and clinical interview, the participants were grouped as healthy controls (n = 15) and currently depressed (n = 14). In the baby-cry task, 30s-long auditory stimuli of baby-cry sounds were presented to simulate four conditions: generic baby-cry (Just-Listen), baby-cry as if it were their own child’s cry (Your-Baby), baby-cry as if it were themselves (Self), and matched control sounds (Noise). Depressed mothers, as compared to healthy controls, showed greater Self versus Just-Listen responses in left extended amygdala and decreased functional coupling between this left extended amygdala as the seed and nucleus accumbens (NAc) in self-oriented (Self versus Just-Listen) and child-oriented (Your-Baby versus Just-Listen) distress signals. Moreover, the extended amygdala’s differential functional connectivity with dorsomedial prefrontal cortex (dmPFC) during the Your-Baby versus Self was increased for depressed mothers and decreased for healthy controls. Thus, depression may affect mothers by increasing baby-cry threat responses and dysregulating associations between threat and heathy child-oriented parenting motivations. These results are discussed in the context of attachment and self-psychology. PMID:28263829
Pedersen, Gitte A; Jensen, Helene H; Schelde, Anne-Sofie B; Toft, Charlotte; Pedersen, Hans N; Ulrichsen, Maj; Login, Frédéric H; Amieva, Manuel R; Nejsum, Lene N
2017-01-01
Foodborne Enteropathogenic Escherichia coli (EPEC) infections of the small intestine cause diarrhea especially in children and are a major cause of childhood death in developing countries. EPEC infects the apical membrane of the epithelium of the small intestine by attaching, effacing the microvilli under the bacteria and then forming microcolonies on the cell surface. We first asked the question where on epithelial cells EPEC attaches and grows. Using models of polarized epithelial monolayers, we evaluated the sites of initial EPEC attachment to the apical membrane and found that EPEC preferentially attached over the cell-cell junctions and formed microcolonies preferentially where three cells come together at tricellular tight junctions. The ability of EPEC to adhere increased when host cell polarity was compromised yielding EPEC access to basolateral proteins. EPEC pedestals contain basolateral cytoskeletal proteins. Thus, we asked if attached EPEC causes reorganization the protein composition of the host cell plasma membrane at sites of microcolony formation. We found that EPEC microcolony growth at the apical membrane resulted in a local accumulation of basolateral plasma membrane proteins surrounding the microcolony. Basolateral marker protein aquaporin-3 localized to forming EPEC microcolonies. Components of the basolateral vesicle targeting machinery were re-routed. The Exocyst (Exo70) was recruited to individual EPEC as was the basolateral vesicle SNARE VAMP-3. Moreover, several Rab variants were also recruited to the infection site, and their dominant-negative equivalents were not. To quantitatively study the recruitment of basolateral proteins, we created a pulse of the temperature sensitive basolateral VSVG, VSVG3-SP-GFP, from the trans-Golgi Network. We found that after release from the TGN, significantly more VSVG3-SP-GFP accumulated at the site of microcolony growth than on equivalent membrane regions of uninfected cells. This suggests that trafficking of vesicles destined for the basolateral membrane are redirected to the apical site of microcolony growth. Thus, in addition to disrupting host cell fence function, local host cell plasma membrane protein composition is changed by altered protein trafficking and recruitment of basolateral proteins to the apical microcolony. This may aid EPEC attachment and subsequent microcolony growth.
Pedersen, Gitte A.; Jensen, Helene H.; Schelde, Anne-Sofie B.; Toft, Charlotte; Pedersen, Hans N.; Ulrichsen, Maj; Login, Frédéric H.; Amieva, Manuel R.
2017-01-01
Foodborne Enteropathogenic Escherichia coli (EPEC) infections of the small intestine cause diarrhea especially in children and are a major cause of childhood death in developing countries. EPEC infects the apical membrane of the epithelium of the small intestine by attaching, effacing the microvilli under the bacteria and then forming microcolonies on the cell surface. We first asked the question where on epithelial cells EPEC attaches and grows. Using models of polarized epithelial monolayers, we evaluated the sites of initial EPEC attachment to the apical membrane and found that EPEC preferentially attached over the cell-cell junctions and formed microcolonies preferentially where three cells come together at tricellular tight junctions. The ability of EPEC to adhere increased when host cell polarity was compromised yielding EPEC access to basolateral proteins. EPEC pedestals contain basolateral cytoskeletal proteins. Thus, we asked if attached EPEC causes reorganization the protein composition of the host cell plasma membrane at sites of microcolony formation. We found that EPEC microcolony growth at the apical membrane resulted in a local accumulation of basolateral plasma membrane proteins surrounding the microcolony. Basolateral marker protein aquaporin-3 localized to forming EPEC microcolonies. Components of the basolateral vesicle targeting machinery were re-routed. The Exocyst (Exo70) was recruited to individual EPEC as was the basolateral vesicle SNARE VAMP-3. Moreover, several Rab variants were also recruited to the infection site, and their dominant-negative equivalents were not. To quantitatively study the recruitment of basolateral proteins, we created a pulse of the temperature sensitive basolateral VSVG, VSVG3-SP-GFP, from the trans-Golgi Network. We found that after release from the TGN, significantly more VSVG3-SP-GFP accumulated at the site of microcolony growth than on equivalent membrane regions of uninfected cells. This suggests that trafficking of vesicles destined for the basolateral membrane are redirected to the apical site of microcolony growth. Thus, in addition to disrupting host cell fence function, local host cell plasma membrane protein composition is changed by altered protein trafficking and recruitment of basolateral proteins to the apical microcolony. This may aid EPEC attachment and subsequent microcolony growth. PMID:28636623
Subsurface Stress Fields in FCC Single Crystal Anisotropic Contacts
NASA Technical Reports Server (NTRS)
Arakere, Nagaraj K.; Knudsen, Erik; Swanson, Gregory R.; Duke, Gregory; Ham-Battista, Gilda
2004-01-01
Single crystal superalloy turbine blades used in high pressure turbomachinery are subject to conditions of high temperature, triaxial steady and alternating stresses, fretting stresses in the blade attachment and damper contact locations, and exposure to high-pressure hydrogen. The blades are also subjected to extreme variations in temperature during start-up and shutdown transients. The most prevalent high cycle fatigue (HCF) failure modes observed in these blades during operation include crystallographic crack initiation/propagation on octahedral planes, and non-crystallographic initiation with crystallographic growth. Numerous cases of crack initiation and crack propagation at the blade leading edge tip, blade attachment regions, and damper contact locations have been documented. Understanding crack initiation/propagation under mixed-mode loading conditions is critical for establishing a systematic procedure for evaluating HCF life of single crystal turbine blades. This paper presents analytical and numerical techniques for evaluating two and three dimensional subsurface stress fields in anisotropic contacts. The subsurface stress results are required for evaluating contact fatigue life at damper contacts and dovetail attachment regions in single crystal nickel-base superalloy turbine blades. An analytical procedure is presented for evaluating the subsurface stresses in the elastic half-space, based on the adaptation of a stress function method outlined by Lekhnitskii. Numerical results are presented for cylindrical and spherical anisotropic contacts, using finite element analysis (FEA). Effects of crystal orientation on stress response and fatigue life are examined. Obtaining accurate subsurface stress results for anisotropic single crystal contact problems require extremely refined three-dimensional (3-D) finite element grids, especially in the edge of contact region. Obtaining resolved shear stresses (RSS) on the principal slip planes also involves considerable post-processing work. For these reasons it is very advantageous to develop analytical solution schemes for subsurface stresses, whenever possible.
NASA Technical Reports Server (NTRS)
Williams, Robert L., III
1992-01-01
This paper presents three methods to solve the inverse position kinematics position problem of the double universal joint attached to a manipulator: (1) an analytical solution for two specific cases; (2) an approximate closed form solution based on ignoring the wrist offset; and (3) an iterative method which repeats closed form position and orientation calculations until the solution is achieved. Several manipulators are used to demonstrate the solution methods: cartesian, cylindrical, spherical, and an anthropomorphic articulated arm, based on the Flight Telerobotic Servicer (FTS) arm. A singularity analysis is presented for the double universal joint wrist attached to the above manipulator arms. While the double universal joint wrist standing alone is singularity-free in orientation, the singularity analysis indicates the presence of coupled position/orientation singularities of the spherical and articulated manipulators with the wrist. The cartesian and cylindrical manipulators with the double universal joint wrist were found to be singularity-free. The methods of this paper can be implemented in a real-time controller for manipulators with the double universal joint wrist. Such mechanically dextrous systems could be used in telerobotic and industrial applications, but further work is required to avoid the singularities.
Koch, Kerstin; Barthlott, Wilhelm; Wandelt, Klaus
2018-01-01
The time dependence of the formation of lotus wax tubules after recrystallization from various chloroform-based solutions on an HOPG surface at room temperature was studied by atomic force microscopy (magnetic AC mode) taking series of consecutive images of the formation process. The growth of the tubules oriented in an upright fashion follows a sequential rodlet→ring→tubule behavior. The influence of a number of factors, e.g., different wax concentration in chloroform, the additional presence of water, or salts [(NH4)2SO4, NH4NO3] or a mixture of salt/water in the solution on the growth rate and orientation of the tubules is also investigated. Different wax concentrations were found to have no effect on the growth rate or the orientation of tubules in none of the solutions. The presence of water, however, considerably increased the growth rate of tubule formation, while the presence of salt was again found to have no effect on growth rate or orientation of tubules. PMID:29515959
Mehdipour, Hamid; Ostrikov, Kostya Ken
2013-02-06
A multiscale, multiphase thermokinetic model is used to show the effective control of the growth orientation of thin Si NWs for nanoelectronic devices enabled by nanoscale plasma chemistry. It is shown that very thin Si NWs with [110] growth direction can nucleate at much lower process temperatures and pressures compared to thermal chemical vapor deposition where [111]-directed Si NWs are predominantly grown. These findings explain a host of experimental results and offer the possibility of energy- and matter-efficient, size- and orientation-controlled growth of [110] Si NWs for next-generation nanodevices.
Culture of human anulus fibrosus cells on polyamide nanofibers: extracellular matrix production.
Gruber, Helen E; Hoelscher, Gretchen; Ingram, Jane A; Hanley, Edward N
2009-01-01
Studies were approved by the authors' Human Subjects Institutional Review Board. Human anulus cells were tested for growth and extracellular matrix (ECM) production in vitro. To investigate cell attachment, cell proliferation, and ECM production of human intervertebral disc anulus cells seeded onto randomly oriented electrospun polyamide nanofibers. Because nanofibrillar matrices have the potential to promote microenvironments, which may mimic in vivo conditions and resemble connective tissue, their utilization opens new avenues for cell-based tissue engineering applications for disc cells. Anulus cells were isolated from 4 cervical spine surgical disc specimens, expanded, and seeded into either routine plastic culture (control) or a nanofiber surface of randomly oriented electrospun polyamide nanofibers (Ultra-Web-coated culture dish, Corning) with a positive charge or without a charge. Cells were cultured for 9 days, digital images captured, cells harvested, embedded in paraffin, and examined for production of extracellular matrix (ECM). Additional anulus cultures were tested to quantitatively assess total proteoglycan production and cell proliferation under control or nanofiber cultures. Cells attached well and exhibited cell extensions within the nanofiber layers; cells on the charged nanofiber surface deposited greater amounts of chondroitin sulfate than of type II collagen than cells cultured on the uncharged nanofiber surface. Results showed that culture of anulus cells on nanofibers was permissive for secretion and assembly of type II collagen and chondroitin sulfate. Significantly greater total proteoglycan formation was present after culture on the nanofiber with added charge conditions {control, 0.6116 microg/mL +/- 0.186 [4] [mean +/- sem(n)] vs. 1.201 +/- 0.2509 [4], P < 0.05}. Cell proliferation, however, did not differ among treatment groups. Culture of anulus cells on nanofibers was found to be permissive for secretion and assembly of type II collagen and chondroitin sulfate, and culture on nanofibers with added charge significantly increased total proteoglycan production. These novel findings point to the need for further examination of nanofibrillar 3D culture of anulus cells for tissue engineering applications.
{l_angle}110{r_angle} dendrite growth in aluminum feathery grains
DOE Office of Scientific and Technical Information (OSTI.GOV)
Henry, S.; Rappaz, M.; Jarry, P.
1998-11-01
Automatic indexing of electron backscattered diffraction patterns, scanning electron microscopy, and optical microscopy observations have been carried out on aluminum-magnesium-silicon, aluminum-copper, and aluminum-silicon alloys directionally solidified or semicontinuously cast using the direct chill casting process. From these combined observations, it is shown that the feathery grains are made of {l_angle}110{r_angle} primary dendrite trunks (e.g., [011{bar 1}]) split in their centers by a coherent (111) twin plane. The average spacing of the dendrite trunks in the twin plane (about 10 to 20 {micro}m) is typically one order of magnitude smaller than that separating successive rows of trunks (or twin planes). Themore » [011{bar 1}] orientation of these trunks is close to the thermal gradient direction (typically within 15 deg)--a feature probably resulting from a growth competition mechanism similar to that occurring during normal <100> columnar dendrite growth. On both sides of these trunks, secondary dendrite arms also grow along {l_angle}110{r_angle} directions. Their impingement creates wavy noncoherent twin boundaries between the coherent twin planes. In the twin plane, evidence is shown that {l_angle}110{r_angle} branching mechanisms lead to the propagation of the twinned regions, to the regular arrangement of the primary dendrite trunks along a [{bar 2}11] direction, and to coherent planar twin boundaries. From these observations, it is concluded that the feathery grains are probably the result of a change from a normal <100> to a {l_angle}110{r_angle} surface tension/attachment kinetics anisotropy growth mode. Finally, the proposed mechanisms of leathery grain growth are further supported by the observation of {l_angle}110{r_angle} dendrite growth morphologies in thin aluminum-zinc coatings.« less
The birth of modern criminology and gendered constructions of homosexual criminal identity.
Woods, Jordan Blair
2015-01-01
There is a dearth of engagement with LGBTQ populations, and sexual orientation and gender identity more broadly, in the field of criminology. This article analyzes the treatment of sexual orientation and gender identity at the birth of the discipline around the 1870 s. Through an analysis of Cesare Lombroso's writings, the article argues that a multifaceted stigma of deviance attached to homosexuality and gender nonconformity in early criminological theory. The article explains this multifaceted stigma in terms of broader political, social, cultural, and legal developments before and during the late nineteenth century that shaped modern Western conceptions of sexual orientation and gender identity.
NASA Technical Reports Server (NTRS)
Joslin, Ronald D.
2004-01-01
The unsteady, incompressible Navier-Stokes equations are used for the direct numerical simulation (DNS) of spatially evolving disturbances in a three-dimensional (3-D) attachment-line boundary layer. Two-dimensional (2-D) disturbances are introduced either by forcing at the in ow or by harmonic-source generators at the wall; 3-D disturbances are introduced by harmonic-source generators at the wall. The DNS results are in good agreement with both 2-D non-parallel theory (for small-amplitude disturbances) and weakly nonlinear theory (for finite-amplitude disturbances), which validates the two theories. The 2-D DNS results indicate that nonlinear disturbance growth occurs near branch II of the neutral stability curve; however, steady suction can be used to stabilize this disturbance growth. For 3-D instabilities that are generated o the attachment line, spreading both toward and away from the attachment line causes energy transfer to the attachment-line and downstream instabilities; suction stabilizes these instabilities. Furthermore, 3-D instabilities are more stable than 2-D or quasi-2-D instabilities.
Yang, Wanlei; Han, Weiqi; He, Wei; Li, Jianlei; Wang, Jirong; Feng, Haotian; Qian, Yu
2016-03-01
Effective and safe induction of osteogenic differentiation is one of the key elements of bone tissue engineering. Surface topography of scaffold materials was recently found to promote osteogenic differentiation. Utilization of this topography may be a safer approach than traditional induction by growth factors or chemicals. The aim of this study is to investigate the enhancement of osteogenic differentiation by surface topography and its mechanism of action. Hydroxyapatite (HA) discs with average roughness (Ra) of surface topography ranging from 0.2 to 1.65 μm and mean distance between peaks (RSm) ranging from 89.7 to 18.6 μm were prepared, and human bone-marrow mesenchymal stem cells (hBMSCs) were cultured on these discs. Optimal osteogenic differentiation was observed on discs with surface topography characterized by Ra ranging from 0.77 to 1.09 μm and RSm ranging from 53.9 to 39.3 μm. On this surface configuration of HA, hBMSCs showed oriented attachment, F-actin arrangement, and a peak in the expression of Yes-associated protein (YAP) and PDZ binding motif (TAZ) (YAP/TAZ). These results indicated that the surface topography of HA promoted osteogenic differentiation of hBMSCs, possibly by increasing cell attachment and promoting the YAP/TAZ signaling pathway. Copyright © 2015 Elsevier B.V. All rights reserved.
Kastenbaum, Hannah A; McPherson, Elizabeth W; Murdoch, Geoffrey H; Ozolek, John A
2009-01-01
Conjoined twinning is a rare form of twinning, in which 2 bodies are attached, and is classified according to the anatomic place of attachment. An extremely rare form of conjoined twinning is janiceps conjoined twinning, in which 2 faces are attached but oriented in opposite directions. In this report, we present an unusual and difficult-to-classify case of conjoined male twins with partial duplication of craniofacial, upper oropharyngeal, and cardiac organs. We believe this to be one of the few reported cases of janiceps asymmetrus. We describe in detail the gross and microscopic pathology and offer some insights into the possible embryogenesis and distinction from the other rare form of conjoined twinning with facial duplication, diprosopus.
Alexander, David J.
1994-01-01
An attachment for placement between a test specimen and a remote clip gage extensometer providing improved fracture toughness tests of materials at elevated temperature. Using a cylindrical tube and axial rod in new relationship, the device transfers the displacement signal of the fracture toughness test specimen directly to a clip gage extensometer located outside the high temperature furnace. Virtually frictionless operation is assured by having the test specimen center one end of the rod in one end of the tube, while the clip gage extensometer arms center the other end of the rod in the other end of the tube. By providing positive control over both ends of both rod and tube, the attachment may be operated in orientations other than vertical.
Pressurizer with a mechanically attached surge nozzle thermal sleeve
Wepfer, Robert M
2014-03-25
A thermal sleeve is mechanically attached to the bore of a surge nozzle of a pressurizer for the primary circuit of a pressurized water reactor steam generating system. The thermal sleeve is attached with a series of keys and slots which maintain the thermal sleeve centered in the nozzle while permitting thermal growth and restricting flow between the sleeve and the interior wall of the nozzle.
Two-stage epitaxial growth of vertically-aligned SnO2 nano-rods on (001) ceria
DOE Office of Scientific and Technical Information (OSTI.GOV)
Solovyov, VF; Wu, LJ; Rupich, MW
2014-12-15
Growth of high-aspect ratio oriented tin oxide, SnO2, nano-rods is complicated by a limited choice of matching substrates. We show that a (001) cerium oxide, CeO2, surface uniquely enables epitaxial growth of tin-oxide nano-rods via a two-stage process. First, (100) oriented nano-wires coat the ceria surface by lateral growth, forming a uniaxially-textured SnO2 deposit. Second, vertical SnO2 nano-rods nucleate on the deposit by homoepitaxy. We demonstrate growth of vertically oriented 1-2 mu m long nano-rods with an average diameter of approximate to 20 nm. 2014 Elsevier B.V. All rights reserved.
1993-03-25
attachment-angle :accessor leg-attachment-angle) (linkO :initform (make-instance ’linkO) :accessor linkO) ( linki :initform (make-instance ’ linki ...accessor linki ) (link2 :initform (make-instance ’link2) :accessor link2) (link3 :initform (make-instance ’link3) :accessor link3) (motion-complete-flag...inboard-link ( linki leg)) (linkO leg)) (setf (inboard-link (link2 leg)) ( linki leg)) (setf (inboard-link (link3 leg)) (link2 leg)) (rotate-link (linkO
NASA Astrophysics Data System (ADS)
Zhang, Shenghong
The intergranular films (IGFs) between the ceramics grains have very important effects on the structure and mechanical properties on the whole ceramics and have been studied for many decades. In the thesis, molecular dynamic (MD) computer simulations were applied to study the IGFs between the alumina and silicon nitride ceramic grains. Preferential adsorption of specific ions from the IGFs to the contacting surfaces of the alumina crystals was observed in the study of calcium-alumino-silicate glassy (CAS) IGFs formed between the combined basal and prism orientations of alpha-Al2O3 crystals. This segregation of specific ions to the interface enables formation of localized, ordered structures between the IGF and the crystals. However, the segregation behavior of the ions is anisotropic, depending on the orientation of the alpha-Al2O 3 crystals. Self-diffusion of calcium ions between these CAS IGFs was also carried out by MD simulations. The results show that the diffusion coefficients adjacent to the interfaces are smaller and the activation energies are much higher than those in the interior of the IGF and in bulk glasses. It was also suggested that Ca transport is mainly though the interior of the IGF and implies that diffusion would be significantly inhibited by sufficiently thin IGFs. The growth of the alumina ceramic grains was simulated in the contacting with IGFs containing high concentrations of aluminum ions. Five different compositions in the IGFs were studied. Results show preferential growth along the [1120] of the (1120) surface in comparison to growth along the [0001] direction on the (0001) surface for compositions near a Ca/Al ratio of 0.5. The simulations also show the mechanism by which Ca ions in the IGF inhibit growth on the basal surface. The simulations provide an atomistic view of attachment onto crystal surfaces, affecting grain growth in alumina. The dissolution of the alumina crystal grains in the silicate melts is another important issue in the application of alumina ceramics. The simulations results showed that alumina grains dissolved into the melts homogeneously at very high temperatures. The orientation of the crystals and the compositions of the melts only take effect at some intermediate temperatures, to make the alumina grains dissolution anisotropic. The fracture phenomena of the pure silica IGFs between the basal silicon nitride crystals were studied by applying the constant tensile strain on the simulated IGF system, as well as for the bulk silica glass for the comparison. The data indicated that the fracture was happened in the interior of the IGFs and the thickness of the IGFs has important effect on the fracture stress/strain relationships.
Fairer, George M.; Boernge, James M.; Harris, David W.; Campbell, DeWayne A.; Tuttle, Gene E.; McKeown, Mark H.; Beason, Steven C.
1993-01-01
The laser goniometer is an apparatus which permits an operator to sight along a geologic feature and orient a collimated lamer beam to match the attitude of the feature directly. The horizontal orientation (strike) and the angle from horizontal (dip), are detected by rotary incremental encoders attached to the laser goniometer which provide a digital readout of the azimuth and tilt of the collimated laser beam. A microprocessor then translates the square wave signal encoder outputs into an ASCII signal for use by data recording equipment.
Electrospun oriented gelatin-hydroxyapatite fiber scaffolds for bone tissue engineering.
Salifu, Ali A; Lekakou, Constantina; Labeed, Fatima H
2017-07-01
Tissue engineering of human fetal osteoblast cells was investigated on gelatin-hydroxyapatite (HA), crosslinked, electrospun oriented fiber scaffolds at the different HA concentrations of 0, 10, 20, and 25 wt % in the dry fibers and different fiber diameter, pore size and porosity of scaffolds. Rheological tests and proton nuclear magnetic resonance spectroscopy were conducted for all solutions used for electrospinning. It was found that 25 wt % HA-gelatin scaffolds electrospun at 20 kV led to the greatest cell attachment, cell proliferation and extracellular matrix (ECM) production while fiber orientation improved the mechanical properties, where crosslinked electrospun 25 wt % HA-gelatin fiber scaffolds yielded a Young's modulus in the range of 0.5-0.9 GPa and a tensile strength in the range of 4-10 MPa in the fiber direction for an applied voltage of 20-30 kV, respectively, in the electrospinning of scaffolds. Biological characterization of cell seeded scaffolds yielded the rate of cell growth and ECM (collagen and calcium) production by the cells as a function of time; it included cell seeding efficiency tests, alamar blue cell proliferation assay, alkaline phosphate (ALP) assay, collagen assay, calcium colorimetric assay, fluorescence microscopy for live and dead cells, and scanning electron microscopy for cell culture from 1 to 18 days. After 18 days, cells seeded and grown on the 25 wt % HA-gelatin scaffold, electrospun at 20 kV, reached production of collagen at 370 μg/L and calcium production at 0.8 mM. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1911-1926, 2017. © 2017 Wiley Periodicals, Inc.
Kennaway, Richard; Coen, Enrico; Green, Amelia; Bangham, Andrew
2011-01-01
A major problem in biology is to understand how complex tissue shapes may arise through growth. In many cases this process involves preferential growth along particular orientations raising the question of how these orientations are specified. One view is that orientations are specified through stresses in the tissue (axiality-based system). Another possibility is that orientations can be specified independently of stresses through molecular signalling (polarity-based system). The axiality-based system has recently been explored through computational modelling. Here we develop and apply a polarity-based system which we call the Growing Polarised Tissue (GPT) framework. Tissue is treated as a continuous material within which regionally expressed factors under genetic control may interact and propagate. Polarity is established by signals that propagate through the tissue and is anchored in regions termed tissue polarity organisers that are also under genetic control. Rates of growth parallel or perpendicular to the local polarity may then be specified through a regulatory network. The resulting growth depends on how specified growth patterns interact within the constraints of mechanically connected tissue. This constraint leads to the emergence of features such as curvature that were not directly specified by the regulatory networks. Resultant growth feeds back to influence spatial arrangements and local orientations of tissue, allowing complex shapes to emerge from simple rules. Moreover, asymmetries may emerge through interactions between polarity fields. We illustrate the value of the GPT-framework for understanding morphogenesis by applying it to a growing Snapdragon flower and indicate how the underlying hypotheses may be tested by computational simulation. We propose that combinatorial intractions between orientations and rates of growth, which are a key feature of polarity-based systems, have been exploited during evolution to generate a range of observed biological shapes. PMID:21698124
Exploring the Impact of an Outdoor Orientation Program on Adaptation to College
ERIC Educational Resources Information Center
Ribbe, Robert, Jr.; Cyrus, Rachael; Langan, Emily
2016-01-01
Outdoor orientation programming as a means for orientating students to college has experienced significant growth and expanded use over the past decade. An increase in rigorous research has accompanied this growth as colleges and universities seek to understand and meet the needs of young adults in transition. In this study, two research questions…
NASA Technical Reports Server (NTRS)
Rosowski, J. R.; Gouthro, M. A.; Schmidt, K. K.; Klement, B. J.; Spooner, B. S.
1995-01-01
Cysts of brine shrimp attached with a liquid adhesive to 12-mm diameter glass coverslips in a syringe-type fluid processing apparatus were flown aboard the NASA space shuttle Discovery, flight STS-60, from 3-11 February 1994, and were allowed to undergo postencystment embryogenesis and to hatch in microgravity. The shuttle flight and the ground-based control coverslips with attached cysts were parallel to the earth's surface during incubation in salt water. Based on the position of the cyst shell crack in the attached cyst population, the ground-control nauplii emerged mostly upward. On the shuttle in microgravity, although our method of detection of orientation would not reveal emergence toward the coverslip, the ratio of the position of the cyst shell crack in the population after hatching best fit the predicted values of a random direction for nauplii emergence. Centrifugation on earth was then used to create hypergravity forces of up to 73 g during postencystment embryogenesis and hatching. The upward orientation of emerging nauplii showed a high degree of correlation (r(2) =98.8%) with a linear relationship to the log of g, with 78.2% of the total hatching upward at 1 g and 91.0% hatching upward at 73 g.
Zerach, Gadi; Tam, Elkanor
2016-01-01
This study examined post-traumatic stress disorder (PTSD) symptoms among young adults that were evicted from their residences in Gaza settlements ("Gush Katif") as adolescents and actively participated in the resistance events. Furthermore, we examined the moderating role of exposure to forced relocation on the association between attachment orientations and family functioning and PTSD symptoms. We conducted a correlative, cross-sectional study in 2013. Participants were Israeli evicted residents (ER group; N = 102), comparison groups of evicted nonresidents (ENR group; N = 27), and nonevicted nonresidents (NENR group; N = 53). All participants completed a battery of self-reported questionnaires. The ER group reported a higher number of PTSD symptoms as compared to the comparison groups. However, ER participants did not differ from ENR and NENR participants in their perception of family functioning. Importantly, the group (ER vs. NENR) moderated the association between attachment-anxiety and PTSD symptoms and between family adaptability and PTSD symptoms. Nine years after the forced relocation from Gaza settlements, young adults that were evicted from their residences as adolescents suffer from PTSD symptoms that are more related to the relocation itself than the stress entailed in the resistance events.
Cutrona, Carolyn E; Russell, Daniel W
2017-02-01
Adult attachment theory provides guidance for providing optimal social support in intimate relationships. According to attachment theory, facilitating autonomy (secure base support) sometimes is more important than providing nurturance (safe haven support). In addition, it is important that couples celebrate one another's triumphs and successes (another form of secure base support). A key construct that explains the development of attachment is responsiveness to the individual's needs. Support that is delivered in a responsive manner (i.e., that leads the individual to feel understood, validated, and cared for) is more likely to enhance the relationship and less likely to damage self-esteem than assistance that is not responsive. A responsive exchange is more likely if emotion dysregulation can be prevented. Attachment theory offers explanations for why people vary in their effectiveness at emotion regulation. Appropriate emotion regulation is more likely if disclosures of current difficulties can be made in a way that is not defensive or accusatory, an ability that varies as a function of attachment orientation. Attachment theory also offers guidance regarding the optimal forms of social support for specific individuals. All these insights from adult attachment theory can be integrated into interventions to help couples become more effective support providers. Copyright © 2016 Elsevier Ltd. All rights reserved.
Mechanically Oriented 3D Collagen Hydrogel for Directing Neurite Growth.
Antman-Passig, Merav; Levy, Shahar; Gartenberg, Chaim; Schori, Hadas; Shefi, Orit
2017-05-01
Recent studies in the field of neuro-tissue engineering have demonstrated the promising effects of aligned contact guidance cue to scaffolds of enhancement and direction of neuronal growth. In vivo, neurons grow and develop neurites in a complex three-dimensional (3D) extracellular matrix (ECM) surrounding. Studies have utilized hydrogel scaffolds derived from ECM molecules to better simulate natural growth. While many efforts have been made to control neuronal growth on 2D surfaces, the development of 3D scaffolds with an elaborate oriented topography to direct neuronal growth still remains a challenge. In this study, we designed a method for growing neurons in an aligned and oriented 3D collagen hydrogel. We aligned collagen fibers by inducing controlled uniaxial strain on gels. To examine the collagen hydrogel as a suitable scaffold for neuronal growth, we evaluated the physical properties of the hydrogel and measured collagen fiber properties. By combining the neuronal culture in 3D collagen hydrogels with strain-induced alignment, we were able to direct neuronal growth in the direction of the aligned collagen matrix. Quantitative evaluation of neurite extension and directionality within aligned gels was performed. The analysis showed neurite growth aligned with collagen matrix orientation, while maintaining the advantageous 3D growth.
Attachment change processes in the early years of marriage.
Davila, J; Karney, B R; Bradbury, T N
1999-05-01
The authors examined 4 models of attachment change: a contextual model, a social-cognitive model, an individual-difference model, and a diathesis-stress model. Models were examined in a sample of newlyweds over the first 2 years of marriage, using growth curve analyses. Reciprocal processes, whereby attachment representations and interpersonal life circumstances affect one another over time, also were studied. On average, newlyweds became more secure over time. However, there was significant within-subject variability on attachment change that was predicted by intra- and interpersonal factors. Attachment representations changed in response to contextual, social-cognitive, and individual-difference factors. Reciprocal processes between attachment representations and marital variables emerged, suggesting that these factors influence one another in an ongoing way.
Zhao, Nan; Zhu, Donghui
2014-01-01
Magnesium (Mg) biomaterials are a new generation of biodegradable materials and have promising potential for orthopedic applications. After implantation in bone tissues, these materials will directly interact with extracellular matrix (ECM) biomolecules and bone cells. Type I collagen, the major component of bone ECM, forms the architecture scaffold that provides physical support for bone cell attachment. However, it is still unknown how Mg substrate affects collagen assembly on top of it as well as subsequent cell attachment and growth. Here, we studied the effects of collagen monomer concentration, pH, assembly time, and surface roughness of two Mg materials (pure Mg and AZ31) on collagen fibril formation. Results showed that formation of fibrils would not initiate until the monomer concentration reached a certain level depending on the type of Mg material. The thickness of collagen fibril increased with the increase of assembly time. The structures of collagen fibrils formed on semi-rough surfaces of Mg materials have a high similarity to that of native bone collagen. Next, cell attachment and growth after collagen assembly were examined. Materials with rough surface showed higher collagen adsorption but compromised bone cell attachment. Interestingly, surface roughness and collagen structure did not affect cell growth on AZ31 for up to a week. Findings from this work provide some insightful information on Mg-tissue interaction at the interface and guidance for future surface modifications of Mg biomaterials. PMID:25303459
Structure evolution of zinc oxide thin films deposited by unbalance DC magnetron sputtering
DOE Office of Scientific and Technical Information (OSTI.GOV)
Aryanto, Didik, E-mail: didi027@lipi.go.id; Materials Research Group, Physics Department, Universitas Negeri Semarang, Gunungpati, Semarang 50229 Jawa Tengah; Marwoto, Putut
Zinc oxide (ZnO) thin films are deposited on corning glass substrates using unbalanced DC magnetron sputtering. The effect of growth temperature on surface morphology and crystallographic orientation of ZnO thin film is studied using atomic force microscopy (AFM) and X-ray diffraction (XRD) techniques. The surface morphology and crystallographic orientation of ZnO thin film are transformed against the increasing of growth temperature. The mean grain size of film and the surface roughness are inversely and directly proportional towards the growth temperature from room temperature to 300 °C, respectively. The smaller grain size and finer roughness of ZnO thin film are obtainedmore » at growth temperature of 400 °C. The result of AFM analysis is in good agreement with the result of XRD analysis. ZnO thin films deposited in a series of growth temperatures have hexagonal wurtzite polycrystalline structures and they exhibit transformations in the crystallographic orientation. The results in this study reveal that the growth temperature strongly influences the surface morphology and crystallographic orientation of ZnO thin film.« less
Cho, Kenneth K; Marjadi, Brahm; Langendyk, Vicki; Hu, Wendy
2017-03-21
Self-regulated learning (SRL), which is learners' ability to proactively select and use different strategies to reach learning goals, is associated with academic and clinical success and life-long learning. SRL does not develop automatically in the clinical environment and its development during the preclinical to clinical learning transition has not been quantitatively studied. Our study aims to fill this gap by measuring SRL in medical students during the transitional period and examining its contributing factors. Medical students were invited to complete a questionnaire at the commencement of their first clinical year (T0), and 10 weeks later (T1). The questionnaire included the Motivated Strategies for Learning Questionnaire (MSLQ) and asked about previous clinical experience. Information about the student's background, demographic characteristics and first clinical rotation were also gathered. Of 118 students invited to participate, complete paired responses were obtained from 72 medical students (response rate 61%). At T1, extrinsic goal orientation increased and was associated with gender (males were more likely to increase extrinsic goal orientation) and type of first attachment (critical care and community based attachments, compared to hospital ward based attachments). Metacognitive self-regulation decreased at T1 and was negatively associated with previous clinical experience. Measurable changes in self-regulated learning occur during the transition from preclinical learning to clinical immersion, particularly in the domains of extrinsic goal orientation and metacognitive self-regulation. Self-determination theory offers possible explanations for this finding which have practical implications and point the way to future research. In addition, interventions to promote metacognition before the clinical immersion may assist in preserving SRL during the transition and thus promote life-long learning skills in preparation for real-world practice.
Tailoring Graphene Morphology and Orientation on Cu(100), Cu(110), and Cu(111)
NASA Astrophysics Data System (ADS)
Jacobberger, Robert; Arnold, Michael
2013-03-01
Graphene CVD on Cu is phenomenologically complex, yielding diverse crystal morphologies, such as lobes, dendrites, stars, and hexagons, of various orientations. We present a comprehensive study of the evolution of these morphologies as a function of Cu surface orientation, pressure, H2:CH4, and nucleation density. Growth was studied on ultra-smooth, epitaxial Cu films inside Cu enclosures to minimize factors that normally complicate growth. With low H2:CH4, Mullins-Sekerka instabilities propagate to form dendrites, indicating transport limited growth. In LPCVD, the dendrites extend hundreds of microns in the 100, 111, and 110 directions on Cu(100), (110), and (111) and are perturbed by twin boundaries. In APCVD, multiple preferred dendrite orientations exist. With increasing H2:CH4, the dendritic nature of growth is suppressed. In LPCVD, square, rectangle, and hexagon crystals form on Cu(100), (110) and (111), reflecting the Cu crystallography. In APCVD, the morphology becomes hexagonal on each surface. If given ample time, every growth regime yields high-quality monolayers with D:G Raman ratio <0.1. The understanding gained here provides a framework to rationally tailor the graphene crystal morphology and orientation.
Mandal, Eugenia; Zalewska, Karolina
2010-01-01
The aim of this study was to diagnose particular personality characteristics of women with suicide attempts: psychological femininity and masculinity, self-appeal, attachment styles, self-presentation strategies and coping styles. A group of 35 adult women who attempted suicide and the control group (35 women) were submitted to a research. The following measures were used: Inventory of Gender Identity (IPP), Strategies of Self-presentation Questionnaire (KSA), Attachment Style Test, Sense of Self-Appeal Scale (SPWA), Coping Inventory of Stressful Situations (CISS). Female suicide-attempters had a lower index of psychological masculinity and a lower sense of self-appeal than women in the control group. They were characterised by an avoidant attachment style, used a strategy of self-depreciation in self-presentation and an emotion-oriented style of coping. The predictors of risk of suicide behaviours that mainly showed: avoidant-attachment style and strategy of self-depreciation in self-presentation. Parasuicides were characterised by lower self-esteem and weak interpersonal skills, which reduced their ways of coping in difficult situations.
Onion epidermis as a new model to study the control of growth anisotropy in higher plants.
Suslov, Dmitry; Verbelen, Jean-Pierre; Vissenberg, Kris
2009-01-01
To elucidate the role of cellulose microfibrils in the control of growth anisotropy, a link between their net orientation, in vitro cell wall extensibility, and anisotropic cell expansion was studied during development of the adaxial epidermis of onion (Allium cepa) bulb scales using polarization confocal microscopy, creep tests, and light microscopy. During growth the net cellulose alignment across the whole thickness of the outer epidermal wall changed from transverse through random to longitudinal and back to transverse relative to the bulb axis. Cell wall extension in vitro was always higher transverse than parallel to the net cellulose alignment. The direction of growth anisotropy was perpendicular to the net microfibril orientation and changed during development from longitudinal to transverse to the bulb axis. The correlation between the degree of growth anisotropy and the net cellulose alignment was poor. Thus the net cellulose microfibril orientation across the whole thickness of the outer periclinal epidermis wall defines the direction but not the degree of growth anisotropy. Strips isolated from the epidermis in the directions perpendicular and transverse to a net cellulose orientation can be used as an extensiometric model to prove a protein involvement in the control of growth anisotropy.
Liang, X; Wang, Z-Y; Liu, H-Y; Lin, Q; Wang, Z; Liu, Y
2015-01-01
to investigate adult attachment status in first-time mothers, and stability and/or changes in maternal sensitivity during infancy. longitudinal study using quantitative and qualitative methods, and statistical modelling. Three home visits were undertaken when the infant was approximately six, nine and 14 months old. The Adult-to-Parental Attachment Experience Survey was used, and scores for three dimensions were obtained: secure-autonomous, preoccupied and dismissive. Maternal sensitivity was assessed at each time point using the Maternal Behaviour Q-Sort by observing interaction between the mother and infant at home. homes and community settings in greater metropolitan Beijing, North China. 83 mothers and infants born in 2010 enrolled in this study. Data were missing for one or more time points in 20 cases. the mean score for maternal sensitivity tended to increase from six to 14 months. Post-hoc analyses of one-way repeated-measures analysis of variance revealed that maternal sensitivity was significantly higher at 14 months than at six or nine months. An unconditional latent growth model (LGM) of maternal sensitivity, estimated using the Bayesian approach, provided a good fit for the data. Using three attachment-related variables as predictors in the conditional LGM, the model fitting indices were found to be sufficient, and the results suggested that the secure score positively predicted the intercept of the growth model, and the dismissive score negatively predicted both the intercept and slope of the growth model. maternal sensitivity increased over time during infancy. Furthermore, individual differences existed in the developmental trajectory, which was influenced by maternal attachment status. knowledge about attachment-related differences in the trajectory of first-time mothers' sensitivity to infants may help midwives and doctors to provide individualised information and support, with special attention given to mothers with a dismissive attachment status. Copyright © 2014 Elsevier Ltd. All rights reserved.
Temporally controlled release of multiple growth factors from a self-assembling peptide hydrogel
NASA Astrophysics Data System (ADS)
Bruggeman, Kiara F.; Rodriguez, Alexandra L.; Parish, Clare L.; Williams, Richard J.; Nisbet, David R.
2016-09-01
Protein growth factors have demonstrated great potential for tissue repair, but their inherent instability and large size prevents meaningful presentation to biologically protected nervous tissue. Here, we create a nanofibrous network from a self-assembling peptide (SAP) hydrogel to carry and stabilize the growth factors. We significantly reduced growth factor degradation to increase their lifespan by over 40 times. To control the temporal release profile we covalently attached polysaccharide chitosan molecules to the growth factor to increase its interactions with the hydrogel nanofibers and achieved a 4 h delay, demonstrating the potential of this method to provide temporally controlled growth factor delivery. We also describe release rate based analysis to examine the growth factor delivery in more detail than standard cumulative release profiles allow and show that the chitosan attachment method provided a more consistent release profile with a 60% reduction in fluctuations. To prove the potential of this system as a complex growth factor delivery platform we demonstrate for the first time temporally distinct release of multiple growth factors from a single tissue specific SAP hydrogel: a significant goal in regenerative medicine.
de Blasio, Birgitte Freiesleben; Seierstad, Taral Guldahl; Aalen, Odd O
2011-01-01
Preferential attachment is a proportionate growth process in networks, where nodes receive new links in proportion to their current degree. Preferential attachment is a popular generative mechanism to explain the widespread observation of power-law-distributed networks. An alternative explanation for the phenomenon is a randomly grown network with large individual variation in growth rates among the nodes (frailty). We derive analytically the distribution of individual rates, which will reproduce the connectivity distribution that is obtained from a general preferential attachment process (Yule process), and the structural differences between the two types of graphs are examined by simulations. We present a statistical test to distinguish the two generative mechanisms from each other and we apply the test to both simulated data and two real data sets of scientific citation and sexual partner networks. The findings from the latter analyses argue for frailty effects as an important mechanism underlying the dynamics of complex networks. PMID:21572513
Mechanically induced orientation of adult rat cardiac myocytes in vitro
NASA Technical Reports Server (NTRS)
Samuel, J.-L.; Vandenburgh, H. H.
1990-01-01
The present study describes the spatial orientation of a population of freshly isolated adult rat cardiac myocytes using a computerized mechanical cell stimulator device for tissue cultured cells. A continuous unidirectional stretch of the substratum at 60 to 400 microns/min for 120 to 30 min, respectively, during the cell attachment period in a serum-free medium was found to induce a significant threefold increase in the number of rod-shaped myocytes oriented parallel to the direction of movement. The myocytes orient less well with unidirectional substratum stretching after their adhesion to the substratum. Adult myocytes plated onto a substratum undergoing continuous 10-percent stretch-relaxation cycling show no significant change in the myocyte orientation or cytoskeletal organization. In addition to the type of mechanical activity, orientation of rod-shaped myocytes is dependent on the speed of the substratum, the final stretch amplitude, and the timing between initiation of substratum stretching and adhesion of myocytes to the substratum.
Bujold, Adina R.
2016-01-01
Tonsils conduct immune surveillance of antigens entering the upper respiratory tract. Despite their immunological function, they are also sites of persistence and invasion of bacterial pathogens. Actinobacillus suis is a common resident of the tonsils of the soft palate in pigs, but under certain circumstances it can invade, causing septicemia and related sequelae. Twenty-four putative adhesins are predicted in the A. suis genome, but to date, little is known about how they might participate in colonization or invasion. To better understand these processes, swine tonsil lysates were characterized by mass spectrometry. Fifty-nine extracellular matrix (ECM) proteins were identified, including small leucine-rich proteoglycans, integrins, and other cell surface receptors. Additionally, attachment of the wild type and 3 adhesin mutants to 5 ECM components was evaluated. Exponential cultures of wild-type A. suis adhered significantly more than stationary cultures to all ECM components studied except collagen I. During exponential growth, the A. suis Δflp1 mutant attached less to collagen IV while the ΔompA mutant attached less to all ECMs. The ΔcomE1 strain attached less to collagen IV, fibronectin, and vitronectin during exponential growth and exhibited differential attachment to collagen I over short adherence time points. These results suggest that Flp1, OmpA, and ComE1 are important during early stages of attachment to ECM components found in tonsils, which supports the notion that other adhesins have compensatory effects during later stages of attachment. PMID:27481253
Father-son attachment and sexual partner orientation in Taiwan.
Lung, For-Wey; Shu, Bih-Ching
2007-01-01
The topic of homosexual adjustment problems has never been explored in Taiwan. The aim of this study was to investigate the role of parental bonding in the adjustment problems of homosexuals. A total of 51 young homosexual males, 100 nonhomosexual personnel with adjustment disorder, and 124 controls were administered the Parental Bonding Instrument, the Eysenck Personality Questionnaire, and the Chinese Health Questionnaire. The final parsimonious logistic regression and structural equation modeling showed paternal attachment, especially paternal overprotection, to be a predisposing factor in the development of homosexuality. Paternal attachment, introversion, and neurotic characteristics were key factors in the development of homosexuals. In particular, paternal overprotection played the most important role in the developmental process of male homosexuals. This study can be used as a reference for clinical personnel in caring for male homosexuals.
Alexander, D.J.
1994-01-04
An attachment for placement between a test specimen and a remote clip gage extensometer providing improved fracture toughness tests of materials at elevated temperature is described. Using a cylindrical tube and axial rod in new relationship, the device transfers the displacement signal of the fracture toughness test specimen directly to a clip gage extensometer located outside the high temperature furnace. Virtually frictionless operation is assured by having the test specimen center one end of the rod in one end of the tube, while the clip gage extensometer arms center the other end of the rod in the other end of the tube. By providing positive control over both ends of both rod and tube, the attachment may be operated in orientations other than vertical. 1 figure.
Rosario, Margaret
2015-01-01
The empirical literature on lesbian, gay, and bisexual (LGB) individuals has predominantly focused on sexual-orientation disparities between LGB and heterosexual individuals on health and adaptation, as well as on the role of gay-related or minority stress in the health and adaptation of LGB individuals. Aside from demographic control variables, the initial predictor is a marker of sexual orientation or LGB-related experience (e.g., minority stress). Missing are potential strengths and vulnerabilities that LGB individuals develop over time and bring to bear on their sexual identity development and other LGB-related experiences. Those strengths and vulnerabilities may have profound consequences for the sexual identity development, health, and adaptation of LGB individuals. Here, I focus on one such set of strengths and vulnerabilities derived from attachment. I conclude by emphasizing the importance of attachment in the lives of LGB individuals and the need to identify other developmental processes that may be equally consequential. PMID:26900586
The Reach of Linear Protein-DNA Dimerizers
Stafford, Ryan L.; Dervan, Peter B.
2008-01-01
A protein-DNA dimerizer constructed from a DNA-binding pyrrole-imidazole polyamide and the peptide FYPWMK facilitates binding of the natural transcription factor Exd to an adjacent DNA site. Previous dimerizers have been constructed with the peptide attached to an internal pyrrole monomer in an overall branched oligomer. Linear oligomers constructed by attaching the peptide to the polyamide C-terminus expand the range of protein-DNA dimerization to six additional DNA sites. Replacing the FYPWMK hexapeptide with a WM dipeptide, which was previously functional in branched compounds, does not lead to a functional linear dimerizer. Instead, inserting an additional lysine generates a minimal, linear WMK tripeptide conjugate that maintains the activity of the larger FYPWMK dimerizers in a single DNA-binding site orientation. These studies provide insight into the importance of linker length and composition, binding site spacing and orientation, and the protein-binding domain content that are important for the optimization of protein DNA-dimerizers suitable for biological experiments. PMID:17949089
Doumen, Sarah; Smits, Ilse; Luyckx, Koen; Duriez, Bart; Vanhalst, Janne; Verschueren, Karine; Goossens, Luc
2012-12-01
Identity formation and the perceived quality of one's peer relationships are theorized to be intimately linked in emerging adulthood. The present study examined the associations between identity styles (i.e., information-oriented, normative, and diffuse-avoidant styles) and the quality of relationships with peers (as indexed by friendship quality and loneliness) in a sample of 343 college students from Belgium. High scores for the information-oriented style were positively related to friendship quality, whereas high scores for the diffuse-avoidant identity style were positively related to loneliness. These direct associations were mediated, at least in part, by attachment-related emotions (i.e., avoidance and anxiety). These associations, both direct and indirect, provide the first evidence linking identity styles and the quality of peer relationships. Suggestions for future research are provided, both at the methodological and the conceptual level. Copyright © 2012 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.
I(CES)-cubes: a modular self-reconfigurable bipartite robotic system
NASA Astrophysics Data System (ADS)
Unsal, Cem; Kiliccote, Han; Khosla, Pradeep K.
1999-08-01
In this manuscript, we introduce I(CES)-Cubes, a class of 3D modular robotic system that is capable of reconfiguring itself in order to adapt to its environment. This is a bipartite system, i.e. a collection of (i) active elements capable of actuation, and (ii) passive elements acting as connectors between actuated elements. Active elements, called links, are 3-DOF manipulators that are capable of attaching/detaching themselves to/from the passive elements. The cubes can then be positioned and oriented using links, which are independent mechatronic elements. Self- reconfiguration property enables the system to performed locomotion tasks over difficult terrain. For example, the system would be capable of moving over obstacles and climbing stairs. These task are performed by positing and orienting cubes and links to form a 3D network with required shape and position. This paper describes the design of the passive and active elements, the attachment mechanics, and several reconfiguration scenarios. Specifics of the hardware implementation and result of experiments with current prototypes are also given.
NASA Technical Reports Server (NTRS)
Heady, Joel; Pereira, J. Michael; Ruggeri, Charles R.; Bobula, George A.
2009-01-01
A test methodology currently employed for large engines was extended to quantify the ballistic containment capability of a small turboshaft engine compressor case. The approach involved impacting the inside of a compressor case with a compressor blade. A gas gun propelled the blade into the case at energy levels representative of failed compressor blades. The test target was a full compressor case. The aft flange was rigidly attached to a test stand and the forward flange was attached to a main frame to provide accurate boundary conditions. A window machined in the case allowed the projectile to pass through and impact the case wall from the inside with the orientation, direction and speed that would occur in a blade-out event. High-peed, digital-video cameras provided accurate velocity and orientation data. Calibrated cameras and digital image correlation software generated full field displacement and strain information at the back side of the impact point.
Growth of organic crystals via attachment and transformation of nanoscopic precursors
NASA Astrophysics Data System (ADS)
Jiang, Yuan; Kellermeier, Matthias; Gebaue, Denis; Lu, Zihao; Rosenberg, Rose; Moise, Adrian; Przybylski, Michael; Cölfen, Helmut
2017-06-01
A key requirement for the understanding of crystal growth is to detect how new layers form and grow at the nanoscale. Multistage crystallization pathways involving liquid-like, amorphous or metastable crystalline precursors have been predicted by theoretical work and have been observed experimentally. Nevertheless, there is no clear evidence that any of these precursors can also be relevant for the growth of crystals of organic compounds. Herein, we present a new growth mode for crystals of DL-glutamic acid monohydrate that proceeds through the attachment of preformed nanoscopic species from solution, their subsequent decrease in height at the surface and final transformation into crystalline 2D nuclei that eventually build new molecular layers by further monomer incorporation. This alternative mechanism provides a direct proof for the existence of multistage pathways in the crystallization of molecular compounds and the relevance of precursor units larger than the monomeric constituents in the actual stage of growth.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Stack, Andrew G; Raiten, Paolo; Gale, Julian D.
2012-01-01
Mineral growth and dissolution are often treated as occurring via a single, reversible process that governs the rate of reaction. We show that multiple, distinct intermediate states can occur during both growth and dissolution. Specifically, we have used metadynamics, a method to efficiently explore the free energy landscape of a system, coupled to umbrella sampling and reactive flux calculations, to examine the mechanism and rates of attachment and detachment of a barium ion onto a stepped, barite (BaSO4) surface. The activation energies calculated for the rate limiting reactions, which are different for attachment and detachment, precisely match those measured experimentallymore » during both growth and dissolution. These results can potentially explain anomalous, non-steady state mineral reaction rates observed experimentally, and will enable the design of more efficient growth inhibitors and facilitate an understanding of the effect of impurities.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bracco, Jacquelyn N.; Gooijer, Yiscka; Higgins, Steven R.
The rate of growth of ionic minerals from solutions with varying aqueous cation:anion ratios may result in significant errors in mineralization rates predicted by commonly-used affinity-based rate equations. To assess the potential influence of solute stoichiometry on barite growth, step velocities on the barite (001) surface have been measured at 108 °C using hydrothermal atomic force microscopy (HAFM) at moderate supersaturation and as a function of the aqueous barium:sulfate ratio (r). Barite growth hillocks at r ~ 1 were bounded bymore » $$\\langle$$120$$\\rangle$$ steps, however at r < 1, kink site densities increased, steps followed a direction vicinal to $$\\langle$$120$$\\rangle$$, and the [010] steps developed. At r > 1, steps roughened and rounded as the kink site density increased. Step velocities peaked at r = 1 and decreased roughly symmetrically as a function of r, indicating the attachment rates of barium and sulfate ions are similar under these conditions. We hypothesize that the differences in our observations at high and low r arise from differences in the attachment rate constants for the obtuse and acute $$\\langle$$120$$\\rangle$$ steps. Based on results at low r, the data suggests the attachment rate constant for barium ions is similar for obtuse and acute steps. Based on results at high r, the data suggests the attachment rate constant for sulfate is greater for obtuse steps than acute steps. In conclusion, utilizing a step growth model developed by Stack and Grantham (2010) the experimental step velocities as a function of r were readily fit while attempts to fit the data using a model developed by Zhang and Nancollas (1998) were less successful.« less
Bracco, Jacquelyn N.; Gooijer, Yiscka; Higgins, Steven R.
2016-03-19
The rate of growth of ionic minerals from solutions with varying aqueous cation:anion ratios may result in significant errors in mineralization rates predicted by commonly-used affinity-based rate equations. To assess the potential influence of solute stoichiometry on barite growth, step velocities on the barite (001) surface have been measured at 108 °C using hydrothermal atomic force microscopy (HAFM) at moderate supersaturation and as a function of the aqueous barium:sulfate ratio (r). Barite growth hillocks at r ~ 1 were bounded bymore » $$\\langle$$120$$\\rangle$$ steps, however at r < 1, kink site densities increased, steps followed a direction vicinal to $$\\langle$$120$$\\rangle$$, and the [010] steps developed. At r > 1, steps roughened and rounded as the kink site density increased. Step velocities peaked at r = 1 and decreased roughly symmetrically as a function of r, indicating the attachment rates of barium and sulfate ions are similar under these conditions. We hypothesize that the differences in our observations at high and low r arise from differences in the attachment rate constants for the obtuse and acute $$\\langle$$120$$\\rangle$$ steps. Based on results at low r, the data suggests the attachment rate constant for barium ions is similar for obtuse and acute steps. Based on results at high r, the data suggests the attachment rate constant for sulfate is greater for obtuse steps than acute steps. In conclusion, utilizing a step growth model developed by Stack and Grantham (2010) the experimental step velocities as a function of r were readily fit while attempts to fit the data using a model developed by Zhang and Nancollas (1998) were less successful.« less
Bacteria Interactions with Dying Diatoms
NASA Astrophysics Data System (ADS)
Smriga, S.; Juarez, G.; Fernandez, V.; Stocker, R.
2016-02-01
Dying phytoplankton are surrounded by microscale gradients of dissolved organic matter (DOM) that can attract bacteria. These 'phycospheres' may impact the trophic transfer of DOM in the marine microbial food web and enable the growth of bacterial populations, yet these effects remain poorly quantified particularly in relation to the physiological state of the phytoplankton. We dissected phycosphere interactions at unprecedented spatial and temporal resolution using the model diatom Thalassiosira weissflogii and the bacterium Marinobacter adhaerans. Diatom stress was stimulated by addition of polyunsaturated aldehyde (PUA) and both diatom and bacterial responses were captured via time-lapse fluorescence microscopy. We found that stressed diatoms underwent lysis 10-15 h after PUA treatment. Coordinated with the timing of this transition into phytodetritus, wild-type Marinobacter accumulated via chemotaxis near the diatoms immediately following lysis. In contrast, at lysis there was no accumulation of either a non-chemotactic or a non-motile mutant of Marinobacter, pointing to behavioral rather than demographic responses as drivers for the accumulation. Despite the lack of response, non-chemotactic as well as non-swimming bacterial cells that by chance attached to or were located near (<30 µm) stressed diatoms experienced more growth than cells further afield. Growth within the phycosphere was even greater after diatom lysis. Through quantification at the microscale, these results reveal that chemotaxis may precede rapid bacterial attachment to stressed and dying diatoms and may be integral to the microbial colonization of new phytodetritus during phytoplankton blooms and bloom collapses in coastal ecosystems. Even while chemotactic cells retain a growth advantage given their ability to sense and respond to lysis events, phycosphere DOM provides growth benefits to both motile and non-motile taxa that become attached to or happen to be co-located with new phytodetrital particles, thus likely influencing the composition of particle-attached microbial communities.
Vertical transport in isotype InAlN/GaN dipole induced diodes grown by molecular beam epitaxy
NASA Astrophysics Data System (ADS)
Fireman, M. N.; Li, Haoran; Keller, Stacia; Mishra, Umesh K.; Speck, James S.
2017-05-01
InAlN dipole diodes were developed and fabricated on both (0001) Ga-Face and (" separators="| 000 1 ¯) N-face oriented GaN on sapphire templates by molecular beam epitaxy. The orientation and direction of the InAlN polarization dipole are functions of the substrate orientation and composition, respectively. Special consideration was taken to minimize growth differences and impurity uptake during growth on these orientations of opposite polarity. Comparison of devices on similarly grown structures with In compositions in excess of 50% reveals that dipole diodes shows poorer forward bias performance and exhibited an increase in reverse bias leakage, regardless of orientation. Similarly, (0001) Ga-face oriented InAlN at a lowered 40% In composition had poor device characteristics, namely, the absence of expected exponential turn on in forward bias. By contrast, at In compositions close to 40%, (" separators="| 000 1 ¯) N-face oriented InAlN devices had excellent performance, with over five orders of magnitude of rectification and extracted barrier heights of 0.53- 0.62 eV; these values are in close agreement with simulation. Extracted ideality factors ranging from 1.08 to 1.38 on these devices are further evidence of their optimal performance. Further discussion focuses on the growth and orientation conditions that may lead to this discrepancy yet emphasizes that with proper design and growth strategy, the rectifying dipole diodes can be achieved with InAlN nitride dipole layers.
McKee, Jason R; Huokuna, Johannes; Martikainen, Lahja; Karesoja, Mikko; Nykänen, Antti; Kontturi, Eero; Tenhu, Heikki; Ruokolainen, Janne; Ikkala, Olli
2014-05-12
Even though nanocomposites have provided a plethora of routes to increase stiffness and strength, achieving increased toughness with suppressed catastrophic crack growth has remained more challenging. Inspired by the concepts of mechanically excellent natural nanomaterials, one-component nanocomposites were fabricated involving reinforcing colloidal nanorod cores with polymeric grafts containing supramolecular binding units. The concept is based on mechanically strong native cellulose nanocrystals (CNC) grafted with glassy polymethacrylate polymers, with side chains that contain 2-ureido-4[1H]-pyrimidone (UPy) pendant groups. The interdigitation of the grafts and the ensuing UPy hydrogen bonds bind the nanocomposite network together. Under stress, UPy groups act as sacrificial bonds: simultaneously providing adhesion between the CNCs while allowing them to first orient and then gradually slide past each other, thus dissipating fracture energy. We propose that this architecture involving supramolecular binding units within side chains of polymer grafts attached to colloidal reinforcements opens generic approaches for tough nanocomposites. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Graphene oxide--MnO2 nanocomposites for supercapacitors.
Chen, Sheng; Zhu, Junwu; Wu, Xiaodong; Han, Qiaofeng; Wang, Xin
2010-05-25
A composite of graphene oxide supported by needle-like MnO(2) nanocrystals (GO-MnO(2) nanocomposites) has been fabricated through a simple soft chemical route in a water-isopropyl alcohol system. The formation mechanism of these intriguing nanocomposites investigated by transmission electron microscopy and Raman and ultraviolet-visible absorption spectroscopy is proposed as intercalation and adsorption of manganese ions onto the GO sheets, followed by the nucleation and growth of the crystal species in a double solvent system via dissolution-crystallization and oriented attachment mechanisms, which in turn results in the exfoliation of GO sheets. Interestingly, it was found that the electrochemical performance of as-prepared nanocomposites could be enhanced by the chemical interaction between GO and MnO(2). This method provides a facile and straightforward approach to deposit MnO(2) nanoparticles onto the graphene oxide sheets (single layer of graphite oxide) and may be readily extended to the preparation of other classes of hybrids based on GO sheets for technological applications.
Prediction of protein orientation upon immobilization on biological and nonbiological surfaces
NASA Astrophysics Data System (ADS)
Talasaz, Amirali H.; Nemat-Gorgani, Mohsen; Liu, Yang; Ståhl, Patrik; Dutton, Robert W.; Ronaghi, Mostafa; Davis, Ronald W.
2006-10-01
We report on a rapid simulation method for predicting protein orientation on a surface based on electrostatic interactions. New methods for predicting protein immobilization are needed because of the increasing use of biosensors and protein microarrays, two technologies that use protein immobilization onto a solid support, and because the orientation of an immobilized protein is important for its function. The proposed simulation model is based on the premise that the protein interacts with the electric field generated by the surface, and this interaction defines the orientation of attachment. Results of this model are in agreement with experimental observations of immobilization of mitochondrial creatine kinase and type I hexokinase on biological membranes. The advantages of our method are that it can be applied to any protein with a known structure; it does not require modeling of the surface at atomic resolution and can be run relatively quickly on readily available computing resources. Finally, we also propose an orientation of membrane-bound cytochrome c, a protein for which the membrane orientation has not been unequivocally determined. electric double layer | electrostatic simulations | orientation flexibility
Activity Recognition Invariant to Sensor Orientation with Wearable Motion Sensors.
Yurtman, Aras; Barshan, Billur
2017-08-09
Most activity recognition studies that employ wearable sensors assume that the sensors are attached at pre-determined positions and orientations that do not change over time. Since this is not the case in practice, it is of interest to develop wearable systems that operate invariantly to sensor position and orientation. We focus on invariance to sensor orientation and develop two alternative transformations to remove the effect of absolute sensor orientation from the raw sensor data. We test the proposed methodology in activity recognition with four state-of-the-art classifiers using five publicly available datasets containing various types of human activities acquired by different sensor configurations. While the ordinary activity recognition system cannot handle incorrectly oriented sensors, the proposed transformations allow the sensors to be worn at any orientation at a given position on the body, and achieve nearly the same activity recognition performance as the ordinary system for which the sensor units are not rotatable. The proposed techniques can be applied to existing wearable systems without much effort, by simply transforming the time-domain sensor data at the pre-processing stage.
NASA Technical Reports Server (NTRS)
Leger, L. J. (Inventor)
1978-01-01
An improved isolation system is provided for attaching ceramic tiles of insulating material to the surface of a structure to be protected against extreme temperatures of the nature expected to be encountered by the space shuttle orbiter. This system isolates the fragile ceramic tiles from thermally and mechanically induced vehicle structural strains. The insulating tiles are affixed to a felt isolation pad formed of closely arranged and randomly oriented fibers by means of a flexible adhesive and in turn the felt pad is affixed to the metallic vehicle structure by an additional layer of flexible adhesive.
Colour stereociné photography with twin cameras through the operation microscope.
Phillips, C I; McDonald, A J
1975-01-01
Two Beaulieu R16 cinecameras attached toa Zeiss operation microscope, OP Mi2, one for each side, produced colour cine films. When these were projected through polarizing filters on to a silver screen, the audience (wearing appropriately oriented polarizing spectacles) achieved a stereoscopic view.
Individuals' Self-Defining Memories as Reflecting Their Strength and Weaknesses
ERIC Educational Resources Information Center
Goldner, Limor; Scharf, Miri
2017-01-01
The associations between attachment orientations, temperament, resilience, and various dimensions of self-defining memories were examined in 83 female Israeli adolescents and young adults. Resiliency and positive temperament were associated with positive qualities of memories, whereas negative emotionality and reactivity were associated with poor…
Microbial colonization and growth on metal sulfides and other mineral surfaces
NASA Technical Reports Server (NTRS)
Caldwell, D.; Sundquist, A. R.; Lawrence, J.; Doyle, A. P.
1985-01-01
To determine whether a bacterial film forms on sulfur minerals in situ, various sulfur containing and other minerals were incubated in Penitencia Creek. The rate of cell growth and attachment within the surface microenvironment of mineral surfaces was also determined. To determine whether surfaces enriched with soluble sulfur substrates (cysteine, glutathione, thioglycolate, sulfite, and thiosulfate) increased the rate of growth or attachment of natural communities, membrane enrichments were incubated. These rates were determined as described by Caldwell et al. (1981, 1983). The growth of Pseudomonas fluorescens, a heterotrophic sulfur oxidizer, was studied in batch cell suspensions and in continuous culture. In batch culture the cells were oxygen limited (growth rate 0.33 per hour under oxygen limitations and 0.52 per hour when vigorously aerated). Growth within the film was glucose limited. Several behavioral phenomena were observed for cells growing within the hydrodynamic boundary layer. Despite a flow of 10 cm per second in the environment, the bacteria were able to move freely in both directions within the hydrodynamic boundary layer.
Spatial and physical frames of reference in positioning a limb.
Garrett, S R; Pagano, C; Austin, G; Turvey, M T
1998-10-01
Splints attached to the right forearm were used to rotate the forearm's physical reference frame, as defined by the eigenvectors of its inertia tensor, relative to its spatial reference frame. In two experiments, when subjects were required to orient the forearm parallel to, or at 45 degrees to, the environmental horizontal, they produced limb orientations that were systematically deflected from the forearm's longitudinal spatial axis in the direction of the forearm's physical axes. The position sense seems to be based on inertial eigenvectors rather than on joint angles or gravitational torques.
Infant Attachment and Separation: The Foundations for Social/Emotional Growth.
ERIC Educational Resources Information Center
Orion, Judi
2002-01-01
Traces encounters between mother and child that occur around nursing and feeding, which result in a powerful attachment. Identifies approaching solid foods and subsequent weaning as the place where detachment begins. Discusses locomotion as another way incremental steps toward independence are reached: crawling, walking, and pulling up with hands…
USDA-ARS?s Scientific Manuscript database
Broad spectrum antibiotics, used to treat infections in livestock, are often administered at sub-therapeutic levels in feed rations to promote growth and for prophylaxis. Previous studies have shown that bacteria preferentially attach to sediments affecting their transport in overland flow; however...
Salcuni, Silvia; Di Riso, Daniela; Lis, Adriana
2014-01-01
There is a gap between proposed theoretical attachment theory frameworks, measures of attachment in the assessment phase and their relationship with changes in outcome after a psychodynamic oriented psychotherapy. Based on a clinical case study of a young woman with Panic Attack Disorder, this paper examined psychotherapy outcome findings comparing initial and post-treatment assessments, according to the mental functioning in S and M-axis of the psychodynamic diagnostic manual. Treatment planning and post-treatment changes were described with the main aim to illustrate from a clinical point of view why a psycho-dynamic approach, with specific attention to an “attachment theory stance,” was considered the treatment of choice for this patient. The Symptom Check List 90 Revised (SCL-90-R) and the Shedler–Westen Assessment Procedure (SWAP–200) were administered to detect patient’s symptomatic perception and clinician’s diagnostic points of view, respectively; the Adult Attachment Interview and the Adult Attachment Projective Picture System (AAP) were also administered as to pay attention to patient’s unconscious internal organization and changes in defense processes. A qualitative description of how the treatment unfolded was included. Findings highlight the important contribution of attachment theory in a 22-month psychodynamic psychotherapy framework, promoting resolution of patient’s symptoms and adjustment. PMID:25191293
Pseudomonas aeruginosa attachment on QCM-D sensors: the role of cell and surface hydrophobicities.
Marcus, Ian M; Herzberg, Moshe; Walker, Sharon L; Freger, Viatcheslav
2012-04-17
While biofilms are ubiquitous in nature, the mechanism by which they form is still poorly understood. This study investigated the process by which bacteria deposit and, shortly after, attach irreversibly to surfaces by reorienting to create a stronger interaction, which leads to biofilm formation. A model for attachment of Pseudomonas aeruginosa was developed using a quartz crystal microbalance with dissipation monitoring (QCM-D) technology, along with a fluorescent microscope and camera to monitor kinetics of adherence of the cells over time. In this model, the interaction differs depending on the force that dominates between the viscous, inertial, and elastic loads. P. aeruginosa, grown to the midexponential growth phase (hydrophilic) and stationary phase (hydrophobic) and two different surfaces, silica (SiO(2)) and polyvinylidene fluoride (PVDF), which are hydrophilic and hydrophobic, respectively, were used to test the model. The bacteria deposited on both of the sensor surfaces, though on the silica surface the cells reached a steady state where there was no net increase in deposition of bacteria, while the quantity of cells depositing on the PVDF surface continued to increase until the end of the experiments. The change in frequency and dissipation per cell were both positive for each overtone (n), except when the cells and surface are both hydrophilic. In the model three factors, specifically, viscous, inertial, and elastic loads, contribute to the change in frequency and dissipation at each overtone when a cell deposits on a sensor. On the basis of the model, hydrophobic cells were shown to form an elastic connection to either surface, with an increase of elasticity at higher overtones. At lower overtones, hydrophilic cells depositing on the hydrophobic surface were shown to also be elastic, but as the overtone increases the connection between the cells and sensor becomes more viscoelastic. In the case of hydrophilic cells interacting with the hydrophilic surface, the connection is viscous at each overtone measured. It could be inferred that the transformation of the viscoelasticity of the cell-surface connection is due to changes in the orientation of the cells to the surface, which allow the bacteria to attach irreversibly and begin biofilm formation. © 2012 American Chemical Society
Bioengineered anterior cruciate ligament
NASA Technical Reports Server (NTRS)
Martin, Ivan (Inventor); Altman, Gregory (Inventor); Kaplan, David (Inventor); Vunjak-Novakovic, Gordana (Inventor)
2001-01-01
The present invention provides a method for producing an anterior cruciate ligament ex vivo. The method comprises seeding pluripotent stem cells in a three dimensional matrix, anchoring the seeded matrix by attachment to two anchors, and culturing the cells within the matrix under conditions appropriate for cell growth and regeneration, while subjecting the matrix to one or more mechanical forces via movement of one or both of the attached anchors. Bone marrow stromal cells are preferably used as the pluripotent cells in the method. Suitable matrix materials are materials to which cells can adhere, such as a gel made from collagen type I. Suitable anchor materials are materials to which the matrix can attach, such as Goinopra coral and also demineralized bone. Optimally, the mechanical forces to which the matrix is subjected mimic mechanical stimuli experienced by an anterior cruciate ligament in vivo. This is accomplished by delivering the appropriate combination of tension, compression, torsion, and shear, to the matrix. The bioengineered ligament which is produced by this method is characterized by a cellular orientation and/or matrix crimp pattern in the direction of the applied mechanical forces, and also by the production of collagen type I, collagen type III, and fibronectin proteins along the axis of mechanical load produced by the mechanical forces. Optimally, the ligament produced has fiber bundles which are arranged into a helical organization. The method for producing an anterior cruciate ligament can be adapted to produce a wide range of tissue types ex vivo by adapting the anchor size and attachment sites to reflect the size of the specific type of tissue to be produced, and also adapting the specific combination of forces applied, to mimic the mechanical stimuli experienced in vivo by the specific type of tissue to be produced. The methods of the present invention can be further modified to incorporate other stimuli experienced in vivo by the particular developing tissue, some examples of the stimuli being chemical stimuli, and electro-magnetic stimuli. Some examples of tissue which can be produced include other ligaments in the body (hand, wrist, elbow, knee), tendon, cartilage, bone, muscle, and blood vessels.
Xylella fastidiosa Differentially Accumulates Mineral Elements in Biofilm and Planktonic Cells
Cobine, Paul A.; Cruz, Luisa F.; Navarrete, Fernando; Duncan, Daniel; Tygart, Melissa; De La Fuente, Leonardo
2013-01-01
Xylella fastidiosa is a bacterial plant pathogen that infects numerous plant hosts. Disease develops when the bacterium colonizes the xylem vessels and forms a biofilm. Inductively coupled plasma optical emission spectroscopy was used to examine the mineral element content of this pathogen in biofilm and planktonic states. Significant accumulations of copper (30-fold), manganese (6-fold), zinc (5-fold), calcium (2-fold) and potassium (2-fold) in the biofilm compared to planktonic cells were observed. Other mineral elements such as sodium, magnesium and iron did not significantly differ between biofilm and planktonic cells. The distribution of mineral elements in the planktonic cells loosely mirrors the media composition; however the unique mineral element distribution in biofilm suggests specific mechanisms of accumulation from the media. A cell-to-surface attachment assay shows that addition of 50 to 100 µM Cu to standard X. fastidiosa media increases biofilm, while higher concentrations (>200 µM) slow cell growth and prevent biofilm formation. Moreover cell-to-surface attachment was blocked by specific chelation of copper. Growth of X. fastidiosa in microfluidic chambers under flow conditions showed that addition of 50 µM Cu to the media accelerated attachment and aggregation, while 400 µM prevented this process. Supplementation of standard media with Mn showed increased biofilm formation and cell-to-cell attachment. In contrast, while the biofilm accumulated Zn, supplementation to the media with this element caused inhibited growth of planktonic cells and impaired biofilm formation. Collectively these data suggest roles for these minerals in attachment and biofilm formation and therefore the virulence of this pathogen. PMID:23349991
Xylella fastidiosa differentially accumulates mineral elements in biofilm and planktonic cells.
Cobine, Paul A; Cruz, Luisa F; Navarrete, Fernando; Duncan, Daniel; Tygart, Melissa; De La Fuente, Leonardo
2013-01-01
Xylella fastidiosa is a bacterial plant pathogen that infects numerous plant hosts. Disease develops when the bacterium colonizes the xylem vessels and forms a biofilm. Inductively coupled plasma optical emission spectroscopy was used to examine the mineral element content of this pathogen in biofilm and planktonic states. Significant accumulations of copper (30-fold), manganese (6-fold), zinc (5-fold), calcium (2-fold) and potassium (2-fold) in the biofilm compared to planktonic cells were observed. Other mineral elements such as sodium, magnesium and iron did not significantly differ between biofilm and planktonic cells. The distribution of mineral elements in the planktonic cells loosely mirrors the media composition; however the unique mineral element distribution in biofilm suggests specific mechanisms of accumulation from the media. A cell-to-surface attachment assay shows that addition of 50 to 100 µM Cu to standard X. fastidiosa media increases biofilm, while higher concentrations (>200 µM) slow cell growth and prevent biofilm formation. Moreover cell-to-surface attachment was blocked by specific chelation of copper. Growth of X. fastidiosa in microfluidic chambers under flow conditions showed that addition of 50 µM Cu to the media accelerated attachment and aggregation, while 400 µM prevented this process. Supplementation of standard media with Mn showed increased biofilm formation and cell-to-cell attachment. In contrast, while the biofilm accumulated Zn, supplementation to the media with this element caused inhibited growth of planktonic cells and impaired biofilm formation. Collectively these data suggest roles for these minerals in attachment and biofilm formation and therefore the virulence of this pathogen.
Apical control, gravitropic signaling, and the growth of lateral roots in Arabidopsis
NASA Astrophysics Data System (ADS)
Mullen, Jack L.; Wolverton, Chris; Hangarter, Roger P.
Most research on gravity responses in plants has focused on primary roots and shoots, which typically grow in a vertical orientation. However, the patterns of lateral organ growth, which generally have large effects on overall plant architecture, are such that the organs are typically not vertical. In lateral roots of Arabidopsis, growth is initially in a nearly horizontal orientation but changes to a near-vertical orientation as the lateral root develops. Although the non-vertical lateral roots are gravitropically competent, following gravitropic reorientation of seedlings, the lateral roots on the upper flank of the primary root have different growth patterns from those on the lower side of the primary root. The differences are in part dependent on reorientation of the primary root, suggesting that gravitropic signaling from the primary root also contributes to the control of lateral root growth. The hormone auxin appears to play a role in this signaling between the primary and lateral roots, as auxin transport inhibitors applied to the primary root affect lateral root growth. Also, lateral roots of pin3 mutants, which are impaired in polar auxin transport, have altered lateral root orientations. However, other signals from the primary root tip also play an important role in regulating lateral root growth.
Attachment and alliance in the treatment of depressed, sexually abused women.
Smith, Phillip N; Gamble, Stephanie A; Cort, Natalie A; Ward, Erin A; He, Hua; Talbot, Nancy L
2012-02-01
Depression among women with sexual abuse histories is less treatment responsive than in general adult samples. One contributor to poorer treatment outcomes may be abused women's difficulties in forming and maintaining secure relationships, as reflected in insecure attachment styles, which could also impede the development of a positive therapeutic alliance. The current study examines how attachment orientation (i.e. anxiety and avoidance) and development of the working alliance are associated with treatment outcomes among depressed women with histories of childhood sexual abuse. Seventy women seeking treatment in a community mental health center who had Major Depressive Disorder and a childhood sexual abuse history were randomized to Interpersonal Psychotherapy or treatment as usual. Greater attachment avoidance and weaker working alliance were each related to worse depression symptom outcomes; these effects were independent of the presence of comorbid Borderline Personality Disorder and Post-Traumatic Stress Disorder. The effect of avoidant attachment on outcomes was not mediated by the working alliance. Further, working alliance had a stronger effect on depression outcomes in the Interpersonal Psychotherapy group. Understanding the influence of attachment style and the working alliance on treatment outcomes can inform efforts to improve the treatments for depressed women with a history of childhood sexual abuse. © 2012 Wiley Periodicals, Inc.
Powers, Sally I; Pietromonaco, Paula R; Gunlicks, Meredith; Sayer, Aline
2006-04-01
This study investigated theoretically predicted links between attachment style and a physiological indicator of stress, salivary cortisol levels, in 124 heterosexual dating couples. Cortisol was assessed at 7 points before and after an experimental conflict negotiation task, creating a trajectory of stress reactivity and recovery for each participant. Growth modeling of cortisol data tested hypotheses that (a) insecurely attached individuals show patterns of greater physiological stress reactions to interpersonal conflict than do securely attached individuals and (b) people with insecurely attached partners show patterns of greater stress in reaction to relationship conflict than those with securely attached partners. Hypothesis 1 was supported, but men and women differed in the type of insecure attachment that predicted stress trajectories. Hypothesis 2 was supported for men, but not for women. The discussion emphasizes the role of gender role norms and partner characteristics in understanding connections between adult attachment and patterns of cortisol responses to interpersonal stress.
Adaptation of BAp crystal orientation to stress distribution in rat mandible during bone growth
NASA Astrophysics Data System (ADS)
Nakano, T.; Fujitani, W.; Ishimoto, T.; Umakoshi, Y.
2009-05-01
Biological apatite (BAp) c-axis orientation strongly depends on stress distribution in vivo and tends to align along the principal stress direction in bones. Dentulous mandible is subjected to a complicated stress condition in vivo during chewing but few studies have been carried out on the BAp c-axis orientation; so the adaptation of BAp crystal orientation to stress distribution was examined in rat dentulous mandible during bone growth and mastication. Female SD rats 4 to 14 weeks old were prepared, and the bone mineral density (BMD) and BAp crystal orientation were analyzed in a cross-section of mandible across the first molar focusing on two positions: separated from and just under the tooth root on the same cross-section perpendicular to the mesiodistal axis. The degree of BAp orientation was analyzed by a microbeam X-ray diffractometer using Cu-Kα radiation equipped with a detector of curved one-dimensional PSPC and two-dimensional PSPC in the reflection and transmission optics, respectively. BMD quickly increased during bone growth up to 14 weeks, although it was independent of the position from the tooth root. In contrast, BAp crystal orientation strongly depended on the age and the position from the tooth root, even in the same cross-section and direction, especially along the mesiodistal and the biting axes. With increased biting stress during bone growth, the degree of BAp orientation increased along the mesiodistal axis in a position separated from the tooth root more than that near the tooth root. In contrast, BAp preferential alignment clearly appeared along the biting axis near the tooth root. We conclude that BAp orientation rather than BMD sensitively adapts to local stress distribution, especially from the chewing stress in vivo in the mandible.
De Yoreo, James J; Gilbert, Pupa U P A; Sommerdijk, Nico A J M; Penn, R Lee; Whitelam, Stephen; Joester, Derk; Zhang, Hengzhong; Rimer, Jeffrey D; Navrotsky, Alexandra; Banfield, Jillian F; Wallace, Adam F; Michel, F Marc; Meldrum, Fiona C; Cölfen, Helmut; Dove, Patricia M
2015-07-31
Field and laboratory observations show that crystals commonly form by the addition and attachment of particles that range from multi-ion complexes to fully formed nanoparticles. The particles involved in these nonclassical pathways to crystallization are diverse, in contrast to classical models that consider only the addition of monomeric chemical species. We review progress toward understanding crystal growth by particle-attachment processes and show that multiple pathways result from the interplay of free-energy landscapes and reaction dynamics. Much remains unknown about the fundamental aspects, particularly the relationships between solution structure, interfacial forces, and particle motion. Developing a predictive description that connects molecular details to ensemble behavior will require revisiting long-standing interpretations of crystal formation in synthetic systems, biominerals, and patterns of mineralization in natural environments. Copyright © 2015, American Association for the Advancement of Science.
NASA Astrophysics Data System (ADS)
Wang, H.; Dudley, M.; Wu, F.; Yang, Y.; Raghothamachar, B.; Zhang, J.; Chung, G.; Thomas, B.; Sanchez, E. K.; Mueller, S. G.; Hansen, D.; Loboda, M. J.
2015-05-01
Synchrotron x-ray topography and KOH etching studies have been carried out on n-type 4H-SiC offcut substrates before and after homoepitaxial growth to study defect replication and strain relaxation processes and identify the nucleation sources of both interfacial dislocations (IDs) and half-loop arrays (HLAs), which are known to have a deleterious effect on device performance. Two cases are reported. In one, they nucleate from short segments of edge-oriented basal plane dislocations (BPDs) in the substrate which are drawn into the epilayer. In the other, they form from segments of half-loops of BPD that are attached to the substrate surface prior to growth which glide into the epilayer. The significance of these findings is: (1) It is demonstrated that it is not necessary for a BPD to intersect the substrate surface in order for it to be replicated into the homoepitaxial layer and take part in nucleation of IDs and HLAs; (2) The conversion of the surface intersections of a substrate BPD half-loop into threading edge dislocations (TEDs) does not prevent it from also becoming involved in nucleation of IDs and HLAs. This means that, while BPD to TED conversion can eliminate most of the BPD transfer into the epilayer, further mitigation may only be possible by continued efforts to reduce the BPD density in substrates by control of temperature-gradient- induced stresses during their physical vapor transport (PVT) growth.
On Higher Education in China and Canada from the Perspective of Humanity-Orientation
ERIC Educational Resources Information Center
Liang, Xiao; Han, Xuefen
2013-01-01
With the rapid development of the social economy, the ideologies, ways of thinking, psychological qualities, and values of contemporary university students have changed significantly. This poses new challenges for traditional teaching administration. Importance has been attached to the humanity issue in university teaching, which attracts wide…
Globalisation, Mergers and "Inadvertent Multi-Campus Universities": Reflections from Wales
ERIC Educational Resources Information Center
Zeeman, Nadine; Benneworth, Paul
2017-01-01
Multi-site universities face the challenge of integrating campuses that may have different profiles and orientations arising from place-specific attachments. Multi-campus universities created via mergers seeking to ensure long-term financial sustainability, and increasing their attractiveness to students, create a tension in campuses' purposes. We…
49 CFR 572.135 - Upper and lower torso assemblies and torso flexion test procedure.
Code of Federal Regulations, 2010 CFR
2010-10-01
... orientation angle may not exceed 20 degrees. (8) Attach the pull cable and the load cell as shown in Figure O4. (9) Apply a tension force in the midsagittal plane to the pull cable as shown in Figure O4 at any...
The Role of Discourse in Teaching Intercultural Professional Communication
ERIC Educational Resources Information Center
Kartabayeva, Ayana A.; Zhaitapova, Altynai A.
2016-01-01
With Kazakhstan's accession to the Bologna Process, particular importance is attached to the professionally-oriented approach of teaching foreign languages to students, which facilitates formation of their foreign language communicative ability. The article deals with the problem of teaching English to students for the purpose of formation of…
FROM ME TO US: THE CONSTRUCTION OF FAMILY ALLIANCE.
Galdiolo, Sarah; Roskam, Isabelle
2016-01-01
This longitudinal prospective and multi-informant study based on a three-wave research program (pregnancy, 12 months' postpartum, and 16 months' postpartum) aimed to determine the process of construction of family alliance, as assessed by the Lausanne Trilogue Play (Fivaz-Depeursinge & Corboz-Warnery, 1999). A model using parents' individual characteristics (i.e., personality traits and attachment orientations) as distal variables, coparenting as a mediator, child's temperament as a moderator, and family alliance as outcome was tested using structural equation modeling on 62 nonreferred families. Results showed that both parents' conscientiousness was positively and mothers' avoidant attachment and fathers' anxious attachment were negatively and indirectly (via coparenting) associated with the family alliance. The discussion underlines mothers' and fathers' different roles and the importance of coparenting as a core mechanism in the development of family alliance. © 2015 Michigan Association for Infant Mental Health.
Meyer, Régis E; Kim, Seoyoung; Obeso, David; Straight, Paul D; Winey, Mark; Dawson, Dean S
2013-03-01
The conserved kinases Mps1 and Ipl1/Aurora B are critical for enabling chromosomes to attach to microtubules so that partner chromosomes will be segregated correctly from each other, but the precise roles of these kinases have been unclear. We imaged live yeast cells to elucidate the stages of chromosome-microtubule interactions and their regulation by Ipl1 and Mps1 through meiosis I. Ipl1 was found to release kinetochore-microtubule (kMT) associations after meiotic entry, liberating chromosomes to begin homologous pairing. Surprisingly, most chromosome pairs began their spindle interactions with incorrect kMT attachments. Ipl1 released these improper connections, whereas Mps1 triggered the formation of new force-generating microtubule attachments. This microtubule release and reattachment cycle could prevent catastrophic chromosome segregation errors in meiosis.
Electron tomography of the microtubule cytoskeleton in multinucleated hyphae of Ashbya gossypii.
Gibeaux, Romain; Lang, Claudia; Politi, Antonio Z; Jaspersen, Sue L; Philippsen, Peter; Antony, Claude
2012-12-01
We report the mechanistic basis guiding the migration pattern of multiple nuclei in hyphae of Ashbya gossypii. Using electron tomography, we reconstructed the cytoplasmic microtubule (cMT) cytoskeleton in three tip regions with a total of 13 nuclei and also the spindle microtubules of four mitotic nuclei. Each spindle pole body (SPB) nucleates three cMTs and most cMTs above a certain length grow according to their plus-end structure. Long cMTs closely align for several microns along the cortex, presumably marking regions where dynein generates pulling forces on nuclei. Close proximity between cMTs emanating from adjacent nuclei was not observed. The majority of nuclei carry duplicated side-by-side SPBs, which together emanate an average of six cMTs, in most cases in opposite orientation with respect to the hyphal growth axis. Such cMT arrays explain why many nuclei undergo short-range back and forth movements. Only occasionally do all six cMTs orient in one direction, a precondition for long-range nuclear bypassing. Following mitosis, daughter nuclei carry a single SPB with three cMTs. The increased probability that all three cMTs orient in one direction explains the high rate of nuclear bypassing observed in these nuclei. The A. gossypii mitotic spindle was found to be structurally similar to that of Saccharomyces cerevisiae in terms of nuclear microtubule (nMT) number, length distribution and three-dimensional organization even though the two organisms differ significantly in chromosome number. Our results suggest that two nMTs attach to each kinetochore in A. gossypii and not only one nMT like in S. cerevisiae.
A Study of Parameters Affecting Fibroblast Morphology in Response to an Applied Mechanical Force
NASA Technical Reports Server (NTRS)
Grymes, Rosalind A.; Sawyer, Christine
1994-01-01
A precisely controlled stretch/relaxation regimen (20% elongation at 6.6 cycles/min) was applied to normal human fetal, neonatal and aged dermal fibroblasts cultured on flexible membranes. Culture conditions included poly (NH2) or collagen type I coated substrate membranes; control cultures were grown on the same pliable material in the absence of applied stretch. Direct observation and immunofluorescence analyses revealed a progressive change in cell body orientation limited to the stretched dermal fibroblast cultures. Monolayers gradually (over 4 days) acquired a symmetric, radial distribution equivalent to the biaxial array of the applied force. At high seeding density, alignment was inhibited in the fetal cell cultures. This cell strain required collagen type I coating for optimal attachment to the flexible membrane, preferring growth in three-dimensional cell 'balls' on the poly(NH2) coated substrate. Neonatal cells also required the collagen type I coating, but both neonatal and aged dermal fibroblasts aligned efficiently at all seeding densities examined. The randomly oriented neonatal cells on the unstretched control membranes spontaneously detached at confluence, as a single cell sheet. Their aligned counterparts did not detach until the applied stretch stimulus was removed. Low concentrations of cytochalasin D (62.5 ng/ml) disrupted the stretch-related alignment response. Rhodamine phalloidin staining visualized fewer actin stress fibers in stretched, aligned cells than in controls. Both intercellular interactions and cytoskeletal integrity mediate the response to mechanical strain. Normal rabbit corneal stroma fibroblasts (NRC) were also analyzed, and failed to orient under these conditions. This cell type may require a different regimen, or a longer time period, to demonstrate alignment behavior. Supported by NASA Space Biology RTOP 199-40-22 and the NASA-ARC Director's Discretionary Fund.
Crystal Orientation Controlled Photovoltaic Properties of Multilayer GaAs Nanowire Arrays.
Han, Ning; Yang, Zai-Xing; Wang, Fengyun; Yip, SenPo; Li, Dapan; Hung, Tak Fu; Chen, Yunfa; Ho, Johnny C
2016-06-28
In recent years, despite significant progress in the synthesis, characterization, and integration of various nanowire (NW) material systems, crystal orientation controlled NW growth as well as real-time assessment of their growth-structure-property relationships still presents one of the major challenges in deploying NWs for practical large-scale applications. In this study, we propose, design, and develop a multilayer NW printing scheme for the determination of crystal orientation controlled photovoltaic properties of parallel GaAs NW arrays. By tuning the catalyst thickness and nucleation and growth temperatures in the two-step chemical vapor deposition, crystalline GaAs NWs with uniform, pure ⟨110⟩ and ⟨111⟩ orientations and other mixture ratios can be successfully prepared. Employing lift-off resists, three-layer NW parallel arrays can be easily attained for X-ray diffraction in order to evaluate their growth orientation along with the fabrication of NW parallel array based Schottky photovoltaic devices for the subsequent performance assessment. Notably, the open-circuit voltage of purely ⟨111⟩-oriented NW arrayed cells is far higher than that of ⟨110⟩-oriented NW arrayed counterparts, which can be interpreted by the different surface Fermi level pinning that exists on various NW crystal surface planes due to the different As dangling bond densities. All this indicates the profound effect of NW crystal orientation on physical and chemical properties of GaAs NWs, suggesting the careful NW design considerations for achieving optimal photovoltaic performances. The approach presented here could also serve as a versatile and powerful platform for in situ characterization of other NW materials.
Carim, Azhar I.; Batara, Nicolas A.; Premkumar, Anjali; ...
2015-11-23
The template-free growth of well ordered, highly anisotropic lamellar structures has been demonstrated during the photoelectrodeposition of Se–Te films, wherein the orientation of the pattern can be directed by orienting the linear polarization of the incident light. This control mechanism was investigated further herein by examining the morphologies of films grown photoelectrochemically using light from two simultaneous sources that had mutually different linear polarizations. Photoelectrochemical growth with light from two nonorthogonally polarized same-wavelength sources generated lamellar morphologies in which the long axes of the lamellae were oriented parallel to the intensity-weighted average polarization orientation. Simulations of light scattering at themore » solution–film interface were consistent with this observation. Computer modeling of these growths using combined full-wave electromagnetic and Monte Carlo growth simulations successfully reproduced the experimental morphologies and quantitatively agreed with the pattern orientations observed experimentally by considering only the fundamental light-material interactions during growth. Deposition with light from two orthogonally polarized same-wavelength as well as different-wavelength sources produced structures that consisted of two intersecting sets of orthogonally oriented lamellae in which the relative heights of the two sets could be varied by adjusting the relative source intensities. Simulations of light absorption were performed in analogous, idealized intersecting lamellar structures and revealed that the lamellae preferentially absorbed light polarized with the electric field vector along their long axes. In conclusion, these data sets cumulatively indicate that anisotropic light scattering and light absorption generated by the light polarization produces the anisotropic morphology and that the resultant morphology is a function of all illumination inputs despite differing polarizations.« less
NASA Astrophysics Data System (ADS)
Yu, Run-lan; Liu, Jing; Tan, Jian-xi; Zeng, Wei-min; Shi, Li-juan; Gu, Guo-hua; Qin, Wen-qing; Qiu, Guan-zhou
2014-04-01
The pH value plays an important role in the bioleaching of sulphide minerals. The effect of pH values on the extracellular polysaccharide secreted by Acidithiobacillus ferrooxidans was investigated in different phases of bacterial growth during chalcopyrite bioleaching. It is found that extracellular polysaccharide secretion from the cells attached to chalcopyrite is more efficiently than that of the free cells in the bioleaching solution. Three factors, pH values, the concentration of soluble metal ions, and the bacterial growth and metabolism, affect extracellular polysaccharide secretion in the free cells, and are related to the bacterial growth phase. Extracellular polysaccharide secretion from the attached cells is mainly dependent on the pH value of the bacterial culture.
Kolos, Elizabeth; Ruys, Andrew J
2015-01-01
In this study porous alumina samples were prepared and then coated using the biomimetic coating technique using a five times Simulated Body Fluid (5.0SBF) as the growth solution. A coating was achieved after pre-treatment with concentrated acid. From elemental analysis, the coating contained calcium and phosphorous, but also sodium and chlorine. Halite was identified by XRD, a sodium chloride phase. Sintering was done to remove the halite phase. Once halite was burnt off, the calcium phosphate crystals were not covered with halite and, therefore, the apatite phases can be clearly observed. Cell culturing showed sufficient cell attachment to the less porous alumina, Sample B, that has more calcium phosphate growth, while the porous alumina, Sample A, with minimal calcium phosphate growth attained very little cell attachment. This is likely due to the contribution that calcium phosphate plays in the attachment of bone-like cells to a bioinert ceramic such as alumina. These results were repeated on both SEM and confocal microscopy analysis. Confocal microscopy was a novel characterisation approach which gave useful information and was a visual aid.
Functional grading of mineral and collagen in the attachment of tendon to bone.
Genin, Guy M; Kent, Alistair; Birman, Victor; Wopenka, Brigitte; Pasteris, Jill D; Marquez, Pablo J; Thomopoulos, Stavros
2009-08-19
Attachment of dissimilar materials is a major challenge because high levels of localized stress may develop at their interfaces. An effective biologic solution to this problem exists at one of nature's most extreme interfaces: the attachment of tendon (a compliant, structural "soft tissue") to bone (a stiff, structural "hard tissue"). The goal of our study was to develop biomechanical models to describe how the tendon-to-bone insertion derives its mechanical properties. We examined the tendon-to-bone insertion and found two factors that give the tendon-to-bone transition a unique grading in mechanical properties: 1), a gradation in mineral concentration, measured by Raman spectroscopy; and 2), a gradation in collagen fiber orientation, measured by polarized light microscopy. Our measurements motivate a new physiological picture of the tissue that achieves this transition, the tendon-to-bone insertion, as a continuous, functionally graded material. Our biomechanical model suggests that the experimentally observed increase in mineral accumulation within collagen fibers can provide significant stiffening of the partially mineralized fibers, but only for concentrations of mineral above a "percolation threshold" corresponding to formation of a mechanically continuous mineral network within each collagen fiber (e.g., the case of mineral connectivity extending from one end of the fiber to the other). Increasing dispersion in the orientation distribution of collagen fibers from tendon to bone is a second major determinant of tissue stiffness. The combination of these two factors may explain the nonmonotonic variation of stiffness over the length of the tendon-to-bone insertion reported previously. Our models explain how tendon-to-bone attachment is achieved through a functionally graded material composition, and provide targets for tissue engineered surgical interventions and biomimetic material interfaces.
Nanosheet controlled epitaxial growth of PbZr0.52Ti0.48O3 thin films on glass substrates
NASA Astrophysics Data System (ADS)
Bayraktar, M.; Chopra, A.; Bijkerk, F.; Rijnders, G.
2014-09-01
Integration of PbZr0.52Ti0.48O3 (PZT) films on glass substrates is of high importance for device applications. However, to make use of the superior ferro- and piezoelectric properties of PZT, well-oriented crystalline or epitaxial growth with control of the crystal orientation is a prerequisite. In this article, we report on epitaxial growth of PZT films with (100)- and (110)-orientation achieved by utilizing Ca2Nb3O10 (CNO) and Ti0.87O2 (TO) nanosheets as crystalline buffer layers. Fatigue measurements demonstrated stable ferroelectric properties of these films up to 5 × 109 cycles. (100)-oriented PZT films on CNO nanosheets show a large remnant polarization of 21 μC/cm2 that is the highest remnant polarization value compared to (110)-oriented and polycrystalline films reported in this work. A piezoelectric response of 98 pm/V is observed for (100)-oriented PZT film which is higher than the values reported in the literature on Si substrates.
Ghandi, Mostafa; Houshmand, Behzad; Nekoofar, Mohammad H; Tabor, Rachel K; Yadeghari, Zahra; Dummer, Paul M H
2013-03-01
Root surface debridement (RSD) is necessary to create an environment suitable for reattachment of the periodontium. Root surface conditioning may aid the formation of a biocompatible surface suitable for cell reattachment. BioPure™ MTAD (mixture of Doxycycline, citric acid and a detergent) is an endodontic irrigant with antibacterial properties and the ability to remove smear layer. It was hypothesized that MTAD may be useful for root surface conditioning. The efficacy of MTAD as a conditioner was measured by examining fibroblast attachment to root surfaces. Thirty-two specimens of human teeth with advanced periodontal disease were used. The surfaces were root planed until smooth. Half of the specimens were treated with 0.9% saline and the other samples with Biopure MTAD. As a negative control group, five further samples were left unscaled with surface calculus. Human gingival fibroblast cells HGF1-PI1 were cultured and poured over the tooth specimens and incubated. After fixation, the samples were sputter-coated with gold and examined with a SEM. The morphology and number of attached, fixed viable cells were examined. The data was analysed using the Mann-Whitney-U statistical test. There was no significant difference between the numbers of attached cells in the experimental group treated with MTAD and the control group treated with saline. Little or no attached cells were seen in the negative control group. RSD created an environment suitable for cell growth and attachment in a laboratory setting. The use of MTAD did not promote the attachment and growth of cells on the surface of human roots following RSD.
Individualism, innovation, and long-run growth.
Gorodnichenko, Yuriy; Roland, Gerard
2011-12-27
Countries having a more individualist culture have enjoyed higher long-run growth than countries with a more collectivist culture. Individualist culture attaches social status rewards to personal achievements and thus, provides not only monetary incentives for innovation but also social status rewards, leading to higher rates of innovation and economic growth.
Individualism, innovation, and long-run growth
Gorodnichenko, Yuriy; Roland, Gerard
2011-01-01
Countries having a more individualist culture have enjoyed higher long-run growth than countries with a more collectivist culture. Individualist culture attaches social status rewards to personal achievements and thus, provides not only monetary incentives for innovation but also social status rewards, leading to higher rates of innovation and economic growth. PMID:22198759
Derbyshire, Brian; Raut, Videshnandan V.
2013-01-01
Historically, wire markers were attached to cemented all-plastic acetabular cups to demarcate the periphery and to measure socket wear. The wire shape was either a semi-circle passing over the pole of the cup, or a circle around the cup equator. More recently, “double-D” shaped markers were introduced with a part-circular aspect passing over the pole and a semi-circular aspect parallel to the equatorial plane. This configuration enabled cup retroversion to be distinguished from anteversion. In this study, the accuracy of radiographic measurement of cup orientation and wear was assessed for cups with “double-D” and circular markers. Each cup was attached to a measurement jig which could vary the anteversion/retroversion and internal/external rotation of the cup. A metal femoral head was fixed within the socket and radiographic images were created for all combinations of cup orientation settings. The images were measured using software with automatic edge detection, and cup orientation and zero-wear accuracies were determined for each setting. The median error for cup version measurements was similar for both types of wire marker (0.2° double-D marker, −0.24° circular marker), but measurements of the circular marker were more repeatable. The median inclination errors were 2.05° (double-D marker) and 0.23° (circular marker). The median overall “zero wear” errors were 0.19 mm (double-D marker) and 0.03 mm (circular marker). Measurements of the circular wire marker were much more repeatable. PMID:23813165
NASA Astrophysics Data System (ADS)
Moor, Andreas; Volkov, Anatoly F.; Efetov, Konstantin B.
2016-03-01
On the basis of the Usadel equation we study a multiterminal Josephson junction. This junction is composed by "magnetic" superconductors Sm, which have singlet pairing and are separated from the normal n wire by spin filters so that the Josephson coupling is caused only by fully polarized triplet components. We show that there is no interaction between triplet Cooper pairs with antiparallel total spin orientations. The presence of an additional singlet superconductor S attached to the n wire leads to a finite Josephson current IQ with an unusual current-phase relation. The density of states in the n wire for different orientations of spins of Cooper pairs is calculated. We derive a general formula for the current IQ in a multiterminal Josephson contact and apply this formula for analysis of two four-terminal Josephson junctions of different structures. It is shown in particular that both the "nematic" and the "magnetic" cases can be realized in these junctions. In a two-terminal structure with parallel filter orientations and in a three-terminal structure with antiparallel filter orientations of the "magnetic" superconductors with attached additional singlet superconductor, we find a nonmonotonic temperature dependence of the critical current. Also, in these structures, the critical current shows a Riedel peak like dependence on the exchange field in the "magnetic" superconductors. Although there is no current through the S/n interface due to orthogonality of the singlet and triplet components, the phase of the order parameter in the superconuctor S is shown to affect the Josephson current in a multiterminal structure.
Khorakian, Alireza; Sharifirad, Mohammad Sadegh
2018-01-01
The impact of implicit leadership theories on performance and the mechanism linking them have received insufficient theoretical and research attention. Drawing on Bandura's social cognitive theory, the present study contributes theory through examining the assertion that higher congruence between followers' implicit leadership theory and the characteristics of supervisors enhance job performance through higher quality of leader-member exchange and self-efficacy. Moreover, in the proposed model, attachment insecurity was considered as the antecedent of the congruence and leader-member exchange in addition to the moderator of the relationship between them. Capitalizing upon Structural Equation Modeling (SEM), this study tested the model in a field study using a sample of employees in knowledge-oriented firms in Iran. The results suggest that the congruence between followers' implicit leadership theory and the characteristics of supervisors does not directly impact performance and leader-member exchange and self-efficacy are the full mediators. The results also showed that attachment insecurity is the predictor of neither the congruence nor the leader-member exchange. Additionally, attachment insecurity moderates the relationship between these two variables in a way that when attachment insecurity is high, the congruence has more positive impact on leader-member exchange.
An innovative approach to attached cultivation of Chlorella vulgaris using different materials.
Jafari, Negar; Shafiee Alavijeh, Razieh; Abdolahnejad, Ali; Farrokhzadeh, Hossein; Amin, Mohammad Mehdi; Ebrahimi, Afshin
2018-05-10
This article investigates the innovative attached cultivation of Chlorella vulgaris (C. vulgaris) using different materials as an alternative to high capital techniques of harvesting such as centrifugation, flocculation, and filtration. A simple attached algal cultivation system was proposed that was equipped by 10 submerged supporting materials which can harvest algal cells, efficiently. The effect of operational parameters such as light intensity, the rate of aeration, and auto-harvesting time was investigated. A chip, durable, and abundant cellulosic material (Kaldnes carriers covered by kenafs, KCCKs) was proposed for auto-harvesting C. vulgaris cells. The results revealed that optimum aeration rate, light intensity, and auto-harvesting of microalgal cells were 3.6 vvm, 10,548 W/m 2 , and 12 days, respectively. Six of these KCCKs had the highest biofilm formation percent up to 33%. In this condition, the rate of cell growth increased to 0.6 mg/cm 2 . Therefore, this system can be used for appropriate auto-harvesting of microalgae in the attached growth systems. C. vulgaris biomass composition is valuable for biodiesel, bioethanol, and animal protein production.
Homography-based visual servo regulation of mobile robots.
Fang, Yongchun; Dixon, Warren E; Dawson, Darren M; Chawda, Prakash
2005-10-01
A monocular camera-based vision system attached to a mobile robot (i.e., the camera-in-hand configuration) is considered in this paper. By comparing corresponding target points of an object from two different camera images, geometric relationships are exploited to derive a transformation that relates the actual position and orientation of the mobile robot to a reference position and orientation. This transformation is used to synthesize a rotation and translation error system from the current position and orientation to the fixed reference position and orientation. Lyapunov-based techniques are used to construct an adaptive estimate to compensate for a constant, unmeasurable depth parameter, and to prove asymptotic regulation of the mobile robot. The contribution of this paper is that Lyapunov techniques are exploited to craft an adaptive controller that enables mobile robot position and orientation regulation despite the lack of an object model and the lack of depth information. Experimental results are provided to illustrate the performance of the controller.
NASA Astrophysics Data System (ADS)
Yanqoritha, Nyimas; Turmuzi, Muhammad; Derlini
2017-05-01
The appropriate process to resolve sewage contamination which have a high organic using anaerobic technology. Hybrid Upflow Anaerobic Sludge Blanket reactor is one of the anaerobic process which consists of a suspended growth media and attached growth media. The reactor has the ability to work at high load rate, sludge produced easily settles, high biomass and the separation of gas, solid and liquid excelent. The purpose of research is to study the acclimatization process in the reactor of Hybrid Upflow Anaerobic Sludge Blanket using a polyvinl chloride ring as the attached growth medium. Reactor of Hybrid Upflow Anaerobic Sludge Blanket use a working volume of 8.6 L. The operation consisting of 3 L suspended reactor and 5.6 L attached reactor. Acclimatization is conducted by providing the substrate from the smallest concentration of COD up to a concentration that will be processed. During the 50th day, acclimatization process assumed the bacteria begin to work, indicated by the dissolved COD and VSS decrease and biogas production. Due to the wastewater containing the high of protein in consequence operational parameters should be controlled and some precautions should be taken to prevent process partially or totally inhibited.
NASA Technical Reports Server (NTRS)
Delzeit, Lance; Nguyen, Cattien; Li, Jun; Han, Jie; Meyyappan, M.
2002-01-01
The development of nano-arrays for sensors and devices requires the growth of arrays with the proper characteristics. One such application is the growth of vertically aligned carbon nanotubes (CNTs) and graphitic carbon fibers (GCFs) for the chemical attachment of probe molecules. The effectiveness of such an array is dependent not only upon the effectiveness of the probe and the interface between that probe and the array, but also the array and the underlaying substrate. If that array is a growth of vertically aligned CNTs or GCFs then the attachment of that array to the surface is of the utmost importance. This attachment provides the mechanical stability and durability of the array, as well as, the electrical properties of that array. If the detection is to be acquired through an electrical measurement, then the appropriate resistance between the array and the surface need to be fabricated into the device. I will present data on CNTs and GCFs grown from both thermal and plasma enhanced chemical vapor deposition. The focus will be on the characteristics of the metal film from which the CNTs and GCFs are grown and the changes that occur due to changes within the growth process.
Crystallography of Alumina-YAG-Eutectic
NASA Technical Reports Server (NTRS)
Farmer, Serene C.; Sayir, Ali; Dickerson, Robert M.; Matson, Lawrence E.
2000-01-01
Multiple descriptions of the alumina-YAG eutectic crystallography appear in the ceramic literature. The orientation between two phases in a eutectic system has direct impact on residual stress, morphology, microstructural stability, and high temperature mechanical properties. A study to demonstrate that the different crystallographic relationships can be correlated with different growth constraints was undertaken. Fibers produced by Laser-Heated Float Zone (LHFZ) and Edge-defined Film-fed Growth (EFG) were examined. A map of the orientation relationship between Al2O3 and Y3Al5O12 and their relationship to the fiber growth axis as a function of pull rate are presented. Regions in which a single orientation predominates are identified.
Horizontal high speed stacking for batteries with prismatic cans
Bartos, Andrew L.; Lin, Yhu-Tin; Turner, III, Raymond D.
2016-06-14
A system and method for stacking battery cells or related assembled components. Generally planar, rectangular (prismatic-shaped) battery cells are moved from an as-received generally vertical stacking orientation to a generally horizontal stacking orientation without the need for robotic pick-and-place equipment. The system includes numerous conveyor belts that work in cooperation with one another to deliver, rotate and stack the cells or their affiliated assemblies. The belts are outfitted with components to facilitate the cell transport and rotation. The coordinated movement between the belts and the components promote the orderly transport and rotation of the cells from a substantially vertical stacking orientation into a substantially horizontal stacking orientation. The approach of the present invention helps keep the stacked assemblies stable so that subsequent assembly steps--such as compressing the cells or attaching electrical leads or thermal management components--may proceed with a reduced chance of error.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sabat, R.K.
Pure magnesium was subjected to plastic deformation through CSM (continuous stiffness measurement) indentation followed by annealing at 200 °C for 30 min. Nucleation of no new grains was observed neither at the twin–twin intersections nor at the multiple twin variants of a grain after annealing. Significant growth of off-basal twin orientation compared to basal twin orientation was observed in the sample after annealing and is attributed to the partial coherent nature of twin boundary in the later case. Further, growth of twins was independent of the strain distribution between parent and twinned grains. - Highlights: • An ‘ex situ’ EBSDmore » of pure Mg during annealing was investigated. • Nucleation of no new grains was observed. • Significant growth of off-basal twin orientation was observed. • Growth of twins may be attributed to the partial coherent nature of twin boundary.« less
Genetics Home Reference: Shprintzen-Goldberg syndrome
... the transforming growth factor beta (TGF-β) signaling pathway. The TGF-β pathway regulates many processes, including cell growth and division ( ... apoptosis ). By attaching to certain proteins in the pathway, the SKI protein blocks TGF-β signaling. The ...
NASA Astrophysics Data System (ADS)
Buldyrev, S. V.; Pammolli, F.; Riccaboni, M.; Yamasaki, K.; Fu, D.-F.; Matia, K.; Stanley, H. E.
2007-05-01
We present a preferential attachment growth model to obtain the distribution P(K) of number of units K in the classes which may represent business firms or other socio-economic entities. We found that P(K) is described in its central part by a power law with an exponent ϕ = 2+b/(1-b) which depends on the probability of entry of new classes, b. In a particular problem of city population this distribution is equivalent to the well known Zipf law. In the absence of the new classes entry, the distribution P(K) is exponential. Using analytical form of P(K) and assuming proportional growth for units, we derive P(g), the distribution of business firm growth rates. The model predicts that P(g) has a Laplacian cusp in the central part and asymptotic power-law tails with an exponent ζ = 3. We test the analytical expressions derived using heuristic arguments by simulations. The model might also explain the size-variance relationship of the firm growth rates.
Quantitative analysis of microtubule orientation in interdigitated leaf pavement cells.
Akita, Kae; Higaki, Takumi; Kutsuna, Natsumaro; Hasezawa, Seiichiro
2015-01-01
Leaf pavement cells are shaped like a jigsaw puzzle in most dicotyledon species. Molecular genetic studies have identified several genes required for pavement cells morphogenesis and proposed that microtubules play crucial roles in the interdigitation of pavement cells. In this study, we performed quantitative analysis of cortical microtubule orientation in leaf pavement cells in Arabidopsis thaliana. We captured confocal images of cortical microtubules in cotyledon leaf epidermis expressing GFP-tubulinβ and quantitatively evaluated the microtubule orientations relative to the pavement cell growth axis using original image processing techniques. Our results showed that microtubules kept parallel orientations to the growth axis during pavement cell growth. In addition, we showed that immersion treatment of seed cotyledons in solutions containing tubulin polymerization and depolymerization inhibitors decreased pavement cell complexity. Treatment with oryzalin and colchicine inhibited the symmetric division of guard mother cells.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Parish, Chad M.; Wang, Kun; Doerner, Russel P.
2016-09-19
We grew nanotendril “fuzz” on tungsten via plasma exposure and performed transmission Kikuchi diffraction (tKD) in scanning electron microscopy of isolated nanotendrils. 900 °C, 10 23 He/m 2sec, 4 × 10 26 He/m 2 exposure of tungsten produced a deep and fully developed nanotendril mat. tKD of isolated nanotendrils indicated that there was no preferred crystallographic direction oriented along the long axes of the tendrils, and the grain boundary character showed slightly preferential orientations. In conclusion, tendril growth is sufficiently non-equilibrium to prevent any preference of growth direction to manifest measurably, and that new high-angle boundaries (with new grains andmore » grain-growth axes) nucleate randomly along the tendrils during growth.« less
Hetero-Orientation Epitaxial Growth of TiO2 Splats on Polycrystalline TiO2 Substrate
NASA Astrophysics Data System (ADS)
Chen, Lin; Yang, Guan-Jun
2018-05-01
In the present study, the effect of titania (TiO2) substrate grain size and orientation on the epitaxial growth of TiO2 splat was investigated. Interestingly, the splat presented comparable grain size with that of substrate, indicating the hereditary feature of grain size. In addition, hetero- and homo-orientation epitaxial growth was observed at deposition temperatures below 400 °C and above 500 °C, respectively. The preferential growth of high-energy (001) face was also observed at low deposition temperatures (≤ 400 °C), which was found to result from dynamic nonequilibrium effect during the thermal spray deposition. Moreover, thermal spray deposition paves the way for a new approach to prepare high-energy (001) facets of TiO2 crystals.
van Leeuwen, Nikki; Rodgers, Rachel; Régner, Isabelle; Chabrol, Henri
2010-11-01
This study explored the contributions of sociocultural and psychopathological factors to suicidal ideation among adolescents. A sample of 292 French high school students with an immigrant background completed a questionnaire assessing suicidal ideation, borderline personality traits, depressive symptoms, parental attachment, life events, acculturation orientations, ethnic identity, cannabis and alcohol consumption, socioeconomic status and academic failure. Although stressful life events, depressive symptoms, and individualism were risk factors, and attachment to parents a protective factor for both boys and girls, some gender differences emerged. Borderline traits (risk factor), assimilation and marginalization (both protective factors) were significant predictors only among girls.
NASA Technical Reports Server (NTRS)
Khurana, J. P.; Best, T. R.; Poff, K. L.
1989-01-01
Phototropic and gravitropic curvature by hypocotyls of Arabidopsis thaliana is minimal when the side of the hook with the cotyledons attached is positioned toward the direction of tropistic curvature, and maximal when that side of the hook is positioned away from the direction of tropistic curvature. Based on these data, it is proposed that the position of the hook with attached cotyledons affects curvature and not stimulus perception. A randomly oriented population of plants exhibited considerable heterogeneity in tropistic curvature. This heterogeneity arises at least in part from the dependence of curvature on the position of the hook.
Khurana, J P; Best, T R; Poff, K L
1989-01-01
Phototropic and gravitropic curvature by hypocotyls of Arabidopsis thaliana is minimal when the side of the hook with the cotyledons attached is positioned toward the direction of tropistic curvature, and maximal when that side of the hook is positioned away from the direction of tropistic curvature. Based on these data, it is proposed that the position of the hook with attached cotyledons affects curvature and not stimulus perception. A randomly oriented population of plants exhibited considerable heterogeneity in tropistic curvature. This heterogeneity arises at least in part from the dependence of curvature on the position of the hook.
Captive and field-tested radio attachments for bald eagles
Buehler, D.A.; Fraser, J.D.; Fuller, M.R.; McAllister, L.S.; Seegar, J.K.D.
1995-01-01
The effects of two radio transmitter attachment techniques on captive and one attachment technique on wild Bald Eagles (Haliaeetus leucocephalus) were studied. A Y-attachment method with a 160-g dummy transmitter was less apt to cause tissue damage on captive birds than an X-attachment method, and loosely fit transmitters caused less damage than tightly fit transmitters Annual survival of wild birds fitted with 65-g transmitters via an X attachment was estimated at 90-95%. As a result of high survival, only five wild birds marked as nestlings were recovered.Two of these birds had superficial pressure sores from tight-fitting harnesses It is recommended that a 1.3-cm space be left between the transmitter and the bird's b ack when radio-tagging post-fiedging Bald Eagles. Additional space, perhaps up to 2.5 cm, is required for nestlings to allow for added growth and development.
Orientation of the N-terminal lobe of the myosin regulatory light chain in skeletal muscle fibers.
Romano, Daniela; Brandmeier, Birgit D; Sun, Yin-Biao; Trentham, David R; Irving, Malcolm
2012-03-21
The orientation of the N-terminal lobe of the myosin regulatory light chain (RLC) in demembranated fibers of rabbit psoas muscle was determined by polarized fluorescence. The native RLC was replaced by a smooth muscle RLC with a bifunctional rhodamine probe attached to its A, B, C, or D helix. Fiber fluorescence data were interpreted using the crystal structure of the head domain of chicken skeletal myosin in the nucleotide-free state. The peak angle between the lever axis of the myosin head and the fiber or actin filament axis was 100-110° in relaxation, isometric contraction, and rigor. In each state the hook helix was at an angle of ∼40° to the lever/filament plane. The in situ orientation of the RLC D and E helices, and by implication of its N- and C-lobes, was similar in smooth and skeletal RLC isoforms. The angle between these two RLC lobes in rigor fibers was different from that in the crystal structure. These results extend previous crystallographic evidence for bending between the two lobes of the RLC to actin-attached myosin heads in muscle fibers, and suggest that such bending may have functional significance in contraction and regulation of vertebrate striated muscle. Copyright © 2012 Biophysical Society. Published by Elsevier Inc. All rights reserved.
NASA Technical Reports Server (NTRS)
Arakere, N. K.; Swanson, G.
2002-01-01
High cycle fatigue (HCF) induced failures in aircraft gas turbine and rocket engine turbopump blades is a pervasive problem. Single crystal nickel turbine blades are being utilized in rocket engine turbopumps and jet engines throughout industry because of their superior creep, stress rupture, melt resistance, and thermomechanical fatigue capabilities over polycrystalline alloys. Currently the most widely used single crystal turbine blade superalloys are PWA 1480/1493, PWA 1484, RENE' N-5 and CMSX-4. These alloys play an important role in commercial, military and space propulsion systems. Single crystal materials have highly orthotropic properties making the position of the crystal lattice relative to the part geometry a significant factor in the overall analysis. The failure modes of single crystal turbine blades are complicated to predict due to the material orthotropy and variations in crystal orientations. Fatigue life estimation of single crystal turbine blades represents an important aspect of durability assessment. It is therefore of practical interest to develop effective fatigue failure criteria for single crystal nickel alloys and to investigate the effects of variation of primary and secondary crystal orientation on fatigue life. A fatigue failure criterion based on the maximum shear stress amplitude /Delta(sub tau)(sub max))] on the 24 octahedral and 6 cube slip systems, is presented for single crystal nickel superalloys (FCC crystal). This criterion reduces the scatter in uniaxial LCF test data considerably for PWA 1493 at 1200 F in air. Additionally, single crystal turbine blades used in the alternate advanced high-pressure fuel turbopump (AHPFTP/AT) are modeled using a large-scale three-dimensional finite element model. This finite element model is capable of accounting for material orthotrophy and variation in primary and secondary crystal orientation. Effects of variation in crystal orientation on blade stress response are studied based on 297 finite element model runs. Fatigue lives at critical points in the blade are computed using finite element stress results and the failure criterion developed. Stress analysis results in the blade attachment region are also presented. Results presented demonstrates that control of secondary and primary crystallographic orientation has the potential to significantly increase a component S resistance to fatigue crack growth with- out adding additional weight or cost. [DOI: 10.1115/1.1413767
Explaining the relationship between attachment anxiety, eating behaviour and BMI.
Wilkinson, Laura L; Rowe, Angela C; Robinson, Eric; Hardman, Charlotte A
2018-05-05
Previous research indicates that attachment anxiety (fear of abandonment) is predictive of overeating and higher body mass index (BMI). The current study explored the nature of the mechanisms underpinning this relationship. Study 1 assessed the relative contribution of 'emotional eating', 'susceptibility to hunger' and 'uncontrolled eating'. Study 2 assessed whether misperception of emotion and poor emotion management would mediate the relationship between attachment anxiety and stress-induced eating (and then BMI). Two cross-sectional online questionnaire studies were conducted (Study 1 N = 665, & Study 2 N = 548), in UK and US-based samples, which assessed attachment orientation and BMI alongside the potential mediators. The relative contribution of emotional eating, susceptibility to hunger and uncontrolled eating (Study 1) and difficulties in emotion regulation and stress-induced eating (Study 2) as mediators of this relationship were examined. In Study 1, parallel multiple mediation analysis (PROCESS) showed that emotional eating and susceptibility to hunger (but not uncontrolled eating) were significant mediators of the relationship between attachment anxiety and BMI. In Study 2, serial mediation analysis showed that difficulties in 'engaging with goal directed behaviours when upset' and stress-induced eating operated in series to significantly mediate the relationship between attachment anxiety and BMI. These findings suggest that attachment anxious individuals feel less capable in disengaging from negative emotions and go on to try to soothe themselves through eating which has a negative impact on their BMI. There was less support for an explanation of the relationship between attachment anxiety and BMI based around the misperception of emotion. Taken together, the findings highlight attachment anxiety and emotion regulation strategies as key targets for interventions that aim to reduce overeating and excess body weight. Copyright © 2018 Elsevier Ltd. All rights reserved.
Gao, Wen; Zhao, Jing; Li, Yang; Cao, Feng-Lin
2015-11-01
To explore the roles of attachment and alexithymia in the severity of post-traumatic stress disorder symptoms and to specify the relationship between sub-dimensions of attachment, alexithymia and posttraumatic stress disorder symptoms in patients with first-time myocardial infarction in mainland China. Patients experiencing myocardial infarction have a risk of developing post-traumatic stress disorder symptoms. However, there have been few studies on the roles of attachment and alexithymia. A cross-sectional survey design. Ninety-seven patients participated in the assessment of post-traumatic stress disorder symptoms, attachment and alexithymia from June-December in 2012. To assess post-traumatic stress disorder symptoms and their correlates, we administered the Post-traumatic Stress Disorder Checklist-Civilian Version, the 20-item Toronto Alexithymia Scale and the Experiences in Close Relationships Scale 5-17 days after the remission of first myocardial infarction attack. Twenty-five (25·77%) patients met the criteria of posttraumatic stress disorder symptoms. Greater attachment anxiety and avoidance were associated with more severe posttraumatic stress disorder symptoms. Except for externally oriented thinking, all dimensions of alexithymia were significantly correlated with post-traumatic stress symptoms. In the regression model, attachment anxiety and difficulties identifying feelings were found to be predictive and the total regression equation explained 24·2% variance of posttraumatic stress disorder symptoms among myocardial infarction patients. First-time myocardial infarction patients were at risk of developing posttraumatic stress disorder symptoms. Attachment anxiety and difficulties identifying feelings were positively associated with posttraumatic stress disorder symptoms in the early stage of myocardial infarction rehabilitation. It is essential to evaluate the causal relationship between attachment, alexithymia and posttraumatic stress disorder symptoms in longitudinal studies. © 2015 John Wiley & Sons Ltd.
Jehl, Z; Rousset, J; Donsanti, F; Renou, G; Naghavi, N; Lincot, D
2010-10-01
The electrodeposition of ZnO nanorods on ZnO:Al films with different orientations is reported. The influence of the total charge exchanged during electrodeposition on the nanorod's geometry (length, diameter, aspect ratio and surface density) and the optical transmission properties of the nanorod arrays is studied on a [0001]-oriented ZnO:Al substrate. The nanorods are highly vertically oriented along the c axis, following the lattice matching with the substrate. The growth on a [1010] and [1120] ZnO:Al-oriented substrate with c axis parallel to the substrate leads to a systematic deviation angle of 55 degrees from the perpendicular direction. This finding has been explained by the occurrence of a minority orientation with the [1011] planes parallel to the surface, with a preferential growth on corresponding [0001] termination. Substrate crystalline orientation is thereby found to be a major parameter in finely tuning the orientation of the nanorod array. This new approach allows us to optimize the light scattering properties of the films.
Some Growth Aspects of Seymeria cassioicies
Charles M. Stangle; Lytton J. Musselman
1981-01-01
The root parasite, Seymeria cassioides, will not initiate height growth without attachment to a host root when grown under normal fertility conditions, although the seedling may remain alive for 40 days or more without a host. During this time the roots elongate markedly. Fresh pine root segments do not influence the direction of root growth. Although S....
Dyadic Perfectionism as a Predictor of Relationship Continuity and Distress among College Students
ERIC Educational Resources Information Center
Lopez, Frederick G.; Fons-Scheyd, Alia; Morua, Wendy; Chaliman, Rebecca
2006-01-01
This study examined the nature and impact of dyadic perfectionism over a 3-month interval within a sample of 116 college students who were currently involved in an intimate heterosexual relationship. Dyadic perfectionism scores were stable and correlated as expected with scores on concurrent measures of adult attachment orientations and…
Family Quality of Life Empowered by Family-Oriented Support
ERIC Educational Resources Information Center
Schippers, Alice; van Boheemen, Marleen
2009-01-01
Professional services for persons with intellectual disabilities (ID) have begun to attach more importance to their environment. The concept of (family-related) quality of life proved to link very well with this idea and lent itself to constructing and evaluating services. One outcome was the emergence of equal partnerships between families,…
Does Interest in Watching the Night-Sky Correlate with Morning-Evening Orientation? A Brief Report
ERIC Educational Resources Information Center
Kelly, William E.
2007-01-01
This article reports two studies investigating the relationship between noctcaelador (psychological attachment to the nightsky), and morning-evening preferences. Study 1 examined the relationship between the Noctcaelador Inventory (Kelly, 2004) and a shortened form of the Horne and Ostberg Morning-Eveningness Questionnaire (Chelminski, Petros,…
ERIC Educational Resources Information Center
Scharf, Miri; Mayseless, Ofra
2009-01-01
Elementary school teachers identified characteristics in 4 major socioemotional domains associated with children's social leadership: self-perception, social anxiety, attachment orientation with peers, and interpersonal goals and skills in close friendships. Participants were 260 4th- and 5th-grade students (126 boys, 134 girls) from 10 classes in…
Cohort Differences in the Structure and Outcomes of an African American Belief System.
ERIC Educational Resources Information Center
Allen, Richard L.; Bagozzi, Richard P.
2001-01-01
Examined the structure of African American belief systems (racial attitudes and self-esteem) and its relationship to wellbeing, other group attachments, and system orientations across different age and generation groups. Interview data from three age-groupings of adults demonstrated substantial similarity across age cohorts in understanding of…
Holding On to Our Kids in a Peer Culture
ERIC Educational Resources Information Center
Mate, Gabor
2010-01-01
The chief and most damaging of the competing attachments undermining parental and elder authority and love is the increasing bonding of children with their peers. The disorder affecting today's young children and adolescents is rooted in their loss of orientation toward the nurturing adults in their lives. For the first time in history, young…
Identifying typical physical activity on smartphone with varying positions and orientations.
Miao, Fen; He, Yi; Liu, Jinlei; Li, Ye; Ayoola, Idowu
2015-04-13
Traditional activity recognition solutions are not widely applicable due to a high cost and inconvenience to use with numerous sensors. This paper aims to automatically recognize physical activity with the help of the built-in sensors of the widespread smartphone without any limitation of firm attachment to the human body. By introducing a method to judge whether the phone is in a pocket, we investigated the data collected from six positions of seven subjects, chose five signals that are insensitive to orientation for activity classification. Decision trees (J48), Naive Bayes and Sequential minimal optimization (SMO) were employed to recognize five activities: static, walking, running, walking upstairs and walking downstairs. The experimental results based on 8,097 activity data demonstrated that the J48 classifier produced the best performance with an average recognition accuracy of 89.6% during the three classifiers, and thus would serve as the optimal online classifier. The utilization of the built-in sensors of the smartphone to recognize typical physical activities without any limitation of firm attachment is feasible.
A technical report on ultrasound-guided scapulocostal syndrome injection.
McCarthy, C; Harmon, D
2016-08-01
We describe a case report and technique for using an ultrasound scanner and a linear transducer to guide serratus posterior superior (SPS) muscle injection. A 43-year-old female presented with chronic pain centered under the right upper portion of her scapula impacting her activities of daily living. For the ultrasound-guided SPS muscle injection, the patient was placed in the prone position. The transducer was oriented in a transverse orientation at the level of the C6-T1 vertebrae. Here the SPS muscle attaches to the lower portion of the ligament nuchae and the intervening interspinous ligaments. The muscle fibers run inferiorly and laterally to attach to the 2nd-5th ribs which were identified along with the lateral portion of the serratus posterior superior muscle which is covered by the scapula. Real-time imaging was used to direct a spinal needle into the trigger points of the SPS muscle, where solution was injected under direct vision. The patient's pain symptoms improved significantly. Serratus posterior superior injection can confirm a diagnosis of scapulocostal syndrome and be therapeutically beneficial.
SCC of Alloy 690 and its Weld Metals
NASA Astrophysics Data System (ADS)
Andresen, Peter L.; Morra, Martin M.; Ahluwalia, Kawaljit
Alloy 690 base metal, HAZ and weld metal were tested in representative PWR primary water at 290 to 360°C. Intergranular cracking was observed in all materials. Growth rates as high as 1.2 × 10-6 mm/s were observed in the S-L orientation with micro structural banded material after cold rolling or forging to align the planes of banding, rolling and cracking. However, not all banded material has exhibited such high growth rates. Growth rates on homogeneous Alloy 690, including extruded CRDM tubing, often showed growth rates in the range of 2 - 8 × 10-8 mm/s in cold worked condition and an S-L orientation. Crack growth rates in some Alloy 690 tests were in the range of 1 to 10 × 10-9 mm/s, primarily in orientations other than S-L. For cracks aligned along the HAZ, growth rates as high as 1.2 × 10-8 mm/s were observed. Alloy 152/52/52i weld metals always exhibited low growth rates, apart from a weld that was further cold worked by 20%, which grew at 7 × 10-9 mm/s.
Rajangam, Thanavel; An, Seong Soo A
2013-01-01
The aim of this study was to fabricate fibrinogen (Fbg) microfibers with different structural characteristics for the development of 3-D tissue-engineering scaffolds. Fabricated Fbg microfibers were investigated for their biomolecule encapsulation, cell adhesion, and proliferations. Microfibers with three different concentrations of Fbg (5, 10, and 15 wt%) were prepared by a gel solvent-extraction method using a silicone rubber tube. Fbg microfibers were covalently modified with fibronectin (FN) by using water-soluble 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide as the cross-linking agent. Fbg microfibers were characterized by their FN cross-linking properties, structural morphology, and in vitro degradation. Furthermore, FN/Fbg microfibers were evaluated for cell attachment and proliferation. The bio-compatibility and cell proliferation of the microfibers were assessed by measuring adenosine triphosphate activity in C2C12 fibroblast cells. Cell attachment and proliferation on microfibers were further examined using fluorescence and scanning electron microscopic images. FN loading on the microfibers was confirmed by fluorescence and infrared spectroscopy. Surface morphology was characterized by scanning electron microscopy, and showed highly aligned nanostructures for fibers made with 15 wt% Fbg, a more porous structure for fibers made with 10 wt% Fbg, and a less porous structure for those made with 5 wt% Fbg. Controlled biodegradation of the fiber was observed for 8 weeks by using an in vitro proteolytic degradation assay. Fbg microfibers with highly aligned nanostructures (15 wt%) showed enhanced biomolecule encapsulation, as well as higher cell adhesion and proliferation than another two types of FN/Fbg fibers (5 and 10 wt%) and unmodified Fbg fibers. The promising results obtained from the present study reveal that optimal structure of Fbg microfibers could be used as a potential substratum for growth factors or drug release, especially in wound healing and vascular tissue engineering, in which fibers could be applied to promote and orient cell adhesion and proliferation. PMID:23515334
Spider texture and amphibole preferred orientations
NASA Astrophysics Data System (ADS)
Shelley, David
1994-05-01
Foliation in blueschist facies chert from California is defined by layers of oriented alkali-amphibole which consistently curve towards and converge on pyrite (and possibly pyrrhotite) crystals. These foliation nodes, not previously described, are called here 'spider texture'. The texture is interpreted in terms of perturbations of the stress field in a matrix undergoing strain about rigid pyrite (or pyrrhotite) crystals, and it has important implications for understanding the mechanisms of amphibole preferred orientation development. Geometrical relationships between spider texture, pressure shadows and quartz preferred orientations suggest that amphiboles grew with a strong preferred orientation along planes of maximum shearing stress. The mechanism of foliation and preferred orientation development probably involved competitive anisotropic growth of amphibole prisms within the small gaps that open at steps on shear planes, followed by additional (micro-) porphyroblastic growth. The first stage of the mechanism is similar to slickenfibre development.
Differentiation of anchoring junctions in tracheal basal cells in the growing rat.
Evans, M J; Cox, R A; Burke, A S; Moller, P C
1992-02-01
A function of airway basal cells is to attach ciliated and nonciliated columnar cells to the basal lamina. The significance of the basal cell in attachment is related to the height of the columnar epithelium. In taller epithelia, basal cells are more numerous and differentiated with respect to anchoring junctional adhesion mechanisms (desmosomes, hemidesmosomes, and the cytoskeleton) than in shorter epithelia. In this study, we determined if basal cell anchoring junctional adhesion mechanisms differentiated during growth of the airway. Tracheas from five 3-day-old, five 30-day-old, and five 90-day-old rats were prepared for electron microscopy and morphometrically studied by standard techniques. The circumference of the trachea increased from 2.5 +/- 0.2 to 7.5 +/- 0.4 mm during growth. The height of the columnar cell increased from 13.4 +/- 1.5 to 24.6 +/- 3.9 microns, and the number of basal cells per millimeter increased from 3.2 +/- 0.7 to 9.6 +/- 1.8 during growth. The number of desmosomes per basal cell profile increased significantly from 1.5 +/- 0.1 to 2.1 +/- 0.1, as did keratin filament volume density from 0.046 +/- 0.05 to 0.098 +/- 0.032. The amount of hemidesmosome attachment per basal cell did not increase significantly during growth of the airway. These data demonstrate that as tracheas grow in circumference, the columnar cells increase in height, basal cells increase in number, and anchoring junctional adhesion mechanisms differentiate in the basal cells. These changes are closely related to the height of the epithelium and result in maintaining a constant amount of attachment between the columnar epithelium and the basal lamina as the epithelium increases in height.
A Research Study on Secure Attachment Using the Primary Caregiving Approach
ERIC Educational Resources Information Center
Ebbeck, Marjory; Phoon, Dora Mei Yong; Tan-Chong, Elizabeth Chai Kim; Tan, Marilyn Ai Bee; Goh, Mandy Lian Mui
2015-01-01
A child's positive sense of well-being is central to their overall growth and development. With an increasing number of mothers in the workforce, many infants and toddlers spend much time in child care services. Hence it is crucial that caregivers provide a secure base for the child to develop secure attachment with educarers. Given multiple…
Method and system for assembling miniaturized devices
Montesanti, Richard C.; Klingmann, Jeffrey L.; Seugling, Richard M.
2013-03-12
An apparatus for assembling a miniaturized device includes a manipulator system including six manipulators operable to position and orient components of the miniaturized device with submicron precision and micron-level accuracy. The manipulator system includes a first plurality of motorized axes, a second plurality of manual axes, and force and torque and sensors. Each of the six manipulators includes at least one translation stage, at least one rotation stage, tooling attached to the at least one translation stage or the at least one rotation stage, and an attachment mechanism disposed at a distal end of the tooling and operable to attach at least a portion of the miniaturized device to the tooling. The apparatus also includes an optical coordinate-measuring machine (OCMM) including a machine-vision system, a laser-based distance-measuring probe, and a touch probe. The apparatus also includes an operator control system coupled to the manipulator system and the OCMM.
Genus Ranges of Chord Diagrams
Burns, Jonathan; Jonoska, Nataša; Saito, Masahico
2015-01-01
A chord diagram consists of a circle, called the backbone, with line segments, called chords, whose endpoints are attached to distinct points on the circle. The genus of a chord diagram is the genus of the orientable surface obtained by thickening the backbone to an annulus and attaching bands to the inner boundary circle at the ends of each chord. Variations of this construction are considered here, where bands are possibly attached to the outer boundary circle of the annulus. The genus range of a chord diagram is the genus values over all such variations of surfaces thus obtained from a given chord diagram. Genus ranges of chord diagrams for a fixed number of chords are studied. Integer intervals that can be, and those that cannot be, realized as genus ranges are investigated. Computer calculations are presented, and play a key role in discovering and proving the properties of genus ranges. PMID:26478650
Genus Ranges of Chord Diagrams.
Burns, Jonathan; Jonoska, Nataša; Saito, Masahico
2015-04-01
A chord diagram consists of a circle, called the backbone, with line segments, called chords, whose endpoints are attached to distinct points on the circle. The genus of a chord diagram is the genus of the orientable surface obtained by thickening the backbone to an annulus and attaching bands to the inner boundary circle at the ends of each chord. Variations of this construction are considered here, where bands are possibly attached to the outer boundary circle of the annulus. The genus range of a chord diagram is the genus values over all such variations of surfaces thus obtained from a given chord diagram. Genus ranges of chord diagrams for a fixed number of chords are studied. Integer intervals that can be, and those that cannot be, realized as genus ranges are investigated. Computer calculations are presented, and play a key role in discovering and proving the properties of genus ranges.
On the use of magnets to disrupt the physiological compass of birds.
Wang, K; Mattern, E; Ritz, T
2006-10-04
Behavioral researchers have attached magnets to birds during orientation experiments, assuming that such magnets will disrupt their ability to obtain magnetic information. Here, we investigate the effect of an attached magnet on the ability to derive directional information from a radical-pair based compass mechanism. We outline in some detail the geometrical symmetries that would allow a bird to identify magnetic directions in a radical-pair based compass. We show that the artificial field through an attached magnet will quickly disrupt the birds' ability to distinguish pole-ward from equator-ward headings, but that much stronger fields are necessary to disrupt their ability to detect the magnetic axis. Together with estimates of the functional limits of a radical-pair based compass, our calculations suggest that artificial fields of comparable size to the geomagnetic field are not generally sufficient to render a radical-pair based compass non-functional.
Li, Yingzi; Naveed, Hammad; Kachalo, Sema; Xu, Lisa X.; Liang, Jie
2014-01-01
Regulation of cell growth and cell division plays fundamental roles in tissue morphogenesis. However, the mechanisms of regulating tissue elongation through cell growth and cell division are still not well understood. The wing imaginal disc of Drosophila provides a model system that has been widely used to study tissue morphogenesis. Here we use a recently developed two-dimensional cellular model to study the mechanisms of regulating tissue elongation in Drosophila wing. We simulate the effects of directional cues on tissue elongation. We also computationally analyze the role of reduced cell size. Our simulation results indicate that oriented cell divisions, oriented mechanical forces, and reduced cell size can all mediate tissue elongation, but they function differently. We show that oriented cell divisions and oriented mechanical forces act as directional cues during tissue elongation. Between these two directional cues, oriented mechanical forces have a stronger influence than oriented cell divisions. In addition, we raise the novel hypothesis that reduced cell size may significantly promote tissue elongation. We find that reduced cell size alone cannot drive tissue elongation. However, when combined with directional cues, such as oriented cell divisions or oriented mechanical forces, reduced cell size can significantly enhance tissue elongation in Drosophila wing. Furthermore, our simulation results suggest that reduced cell size has a short-term effect on cell topology by decreasing the frequency of hexagonal cells, which is consistent with experimental observations. Our simulation results suggest that cell divisions without cell growth play essential roles in tissue elongation. PMID:24504016
DOE Office of Scientific and Technical Information (OSTI.GOV)
Xu,S.; Gu, J.; Belknap, B.
2006-01-01
When myosin is attached to actin in a muscle cell, various structures in the filaments are formed. The two strongly bound states (A{center_dot}M{center_dot}ADP and A{center_dot}M) and the weakly bound A{center_dot}M{center_dot}ATP states are reasonably well understood. The orientation of the strongly bound myosin heads is uniform ('stereospecific' attachment), and the attached heads exhibit little spatial fluctuation. In the prehydrolysis weakly bound A{center_dot}M{center_dot}ATP state, the orientations of the attached myosin heads assume a wide range of azimuthal and axial angles, indicating considerable flexibility in the myosin head. The structure of the other weakly bound state, A{center_dot}M{center_dot}ADP{center_dot}P{sub i}, however, is poorly understood. Thismore » state is thought to be the critical pre-power-stroke state, poised to make the transition to the strongly binding, force-generating states, and hence it is of particular interest for understanding the mechanism of contraction. However, because of the low affinity between myosin and actin in the A{center_dot}M{center_dot}ADP{center_dot}P{sub i} state, the structure of this state has eluded determination both in isolated form and in muscle cells. With the knowledge recently gained in the structures of the weakly binding M{center_dot}ATP, M{center_dot}ADP{center_dot}P{sub i} states and the weakly attached A{center_dot}M{center_dot}ATP state in muscle fibers, it is now feasible to delineate the in vivo structure of the attached state of A{center_dot}M{center_dot}ADP{center_dot}P{sub i}. The series of experiments presented in this article were carried out under relaxing conditions at 25{sup o}C, where {approx}95% of the myosin heads in the skinned rabbit psoas muscle contain the hydrolysis products. The affinity for actin is enhanced by adding polyethylene glycol (PEG) or by lowering the ionic strength in the bathing solution. Solution kinetics and binding constants were determined in the presence and in the absence of PEG. When the binding between actin and myosin was increased, both the myosin layer lines and the actin layer lines increased in intensity, but the intensity profiles did not change. The configuration (mode) of attachment in the A{center_dot}M{center_dot}ADP{center_dot}P{sub i} state is thus unique among the intermediate attached states of the cross-bridge ATP hydrolysis cycle. One of the simplest explanations is that both myosin filaments and actin filaments are stabilized (e.g., undergo reduced spatial fluctuations) by the attachment. The alignment of the myosin heads in the thick filaments and the alignment of the actin monomers in the thin filaments are improved as a result. The compact atomic structure of M{center_dot}ADP{center_dot}P{sub i} with strongly coupled domains may contribute to the unique attachment configuration: the 'primed' myosin heads may function as 'transient struts' when attached to the thin filaments.« less
Attachment and development: a prospective, longitudinal study from birth to adulthood.
Sroufe, L Alan
2005-12-01
There is much to digest in a 30 year longitudinal study of the developing person (Sroufe, Egeland, Carlson, & Collins, 2005a). The following paper summarizes some key points regarding the place of infant attachment in the developmental course. It is argued that understanding the role of attachment entails grasping the organizational nature of the attachment construct and embracing a non-linear transactional model. Using such concepts, attachment history was shown in the Minnesota study to be clearly related to the growth of self-reliance, the capacity for emotional regulation, and the emergence and course of social competence, among other things. Moreover, specific patterns of attachment had implications for both normal development and pathology. Even more important than such linkages, however, study of the place of early attachment in later adaptation reveals much about developmental processes underlying both continuity and change. Findings are over-viewed concerning the complex links between attachment and ultimate outcomes and the preservation of early patterns even during times of change. In all, these findings have implications both for future research and for clinical application.
Direction of illumination controls gametophyte orientation in seedless plants and related algae
Cardona-Correa, Christopher; Ecker, Alice; Graham, Linda E
2015-01-01
The environmental influences that determine dorsiventral or axial gametophyte orientation are unknown for most modern seedless plants. To fill this gap, an experimental laboratory system was employed to evaluate the relative effects of light direction and gravity on body orientation of the dorsiventral green alga Coleochaete orbicularis, and gametophytes of liverworts Blasia pusilla and Marchantia polymorpha, early-diverging moss Sphagnum compactum, and fern Ceratopteris richardii, the latter functioning as experimental control. Replicate clonal cultures were experimentally illuminated only from above, only from below, or from multiple directions, with the same near-saturation PAR level for periods brief enough to minimize nutrient limitation effects, and orientation of new growth was evaluated. For all species tested, direction of illumination exerted stronger control over gametophyte body orientation than gravity. When illuminated only from below: 1) axial Sphagnum gametophores that had initially grown into an overlying air space inverted growth by 180°, burrowing into the substrate; 2) new growth of dorsiventral Blasia, Marchantia, and Ceratopteris gametophytes–whose ventral rhizoids initially penetrated agar substrate and dorsal surfaces initially faced overlying airspace–twisted 180° so that ventral surfaces bearing rhizoids faced overlying air space and rhizoids extended into the air; and 3) Coleochaete lost typical dorsiventral organization and diagnostic dorsal hairs. Direction of illumination also exerted stronger control over orientation of liverwort new growth than surface contact did. These results indicate that early land plants likely inherited light-directed gametophyte body orientation from ancestral streptophyte algae and suggest a mechanism for reorientation of gametophyte-dominant land plants after spatial disturbance. PMID:26237278
Direction of illumination controls gametophyte orientation in seedless plants and related algae.
Cardona-Correa, Christopher; Ecker, Alice; Graham, Linda E
2015-01-01
The environmental influences that determine dorsiventral or axial gametophyte orientation are unknown for most modern seedless plants. To fill this gap, an experimental laboratory system was employed to evaluate the relative effects of light direction and gravity on body orientation of the dorsiventral green alga Coleochaete orbicularis, and gametophytes of liverworts Blasia pusilla and Marchantia polymorpha, early-diverging moss Sphagnum compactum, and fern Ceratopteris richardii, the latter functioning as experimental control. Replicate clonal cultures were experimentally illuminated only from above, only from below, or from multiple directions, with the same near-saturation PAR level for periods brief enough to minimize nutrient limitation effects, and orientation of new growth was evaluated. For all species tested, direction of illumination exerted stronger control over gametophyte body orientation than gravity. When illuminated only from below: 1) axial Sphagnum gametophores that had initially grown into an overlying air space inverted growth by 180°, burrowing into the substrate; 2) new growth of dorsiventral Blasia, Marchantia, and Ceratopteris gametophytes-whose ventral rhizoids initially penetrated agar substrate and dorsal surfaces initially faced overlying airspace-twisted 180° so that ventral surfaces bearing rhizoids faced overlying air space and rhizoids extended into the air; and 3) Coleochaete lost typical dorsiventral organization and diagnostic dorsal hairs. Direction of illumination also exerted stronger control over orientation of liverwort new growth than surface contact did. These results indicate that early land plants likely inherited light-directed gametophyte body orientation from ancestral streptophyte algae and suggest a mechanism for reorientation of gametophyte-dominant land plants after spatial disturbance.
NASA Technical Reports Server (NTRS)
Solis, Eduardo; Meyn, Larry
2016-01-01
Calibrating the internal, multi-component balance mounted in the Tiltrotor Test Rig (TTR) required photogrammetric measurements to determine the location and orientation of forces applied to the balance. The TTR, with the balance and calibration hardware attached, was mounted in a custom calibration stand. Calibration loads were applied using eleven hydraulic actuators, operating in tension only, that were attached to the forward frame of the calibration stand and the TTR calibration hardware via linkages with in-line load cells. Before the linkages were installed, photogrammetry was used to determine the location of the linkage attachment points on the forward frame and on the TTR calibration hardware. Photogrammetric measurements were used to determine the displacement of the linkage attachment points on the TTR due to deflection of the hardware under applied loads. These measurements represent the first photogrammetric deflection measurements to be made to support 6-component rotor balance calibration. This paper describes the design of the TTR and the calibration hardware, and presents the development, set-up and use of the photogrammetry system, along with some selected measurement results.
Attachment insecurity and psychological resources associated with adjustment disorders.
Ponizovsky, Alexander M; Levov, Kathy; Schultz, Yakov; Radomislensky, Ira
2011-04-01
This study examined the adult attachment styles, interpersonal distance from potential attachment figures and strangers, coping strategies, perceived social support, and stress-related self-variables among patients diagnosed with adjustment disorders (AJD). Seventy patients at an outpatient clinic and 61 matched controls completed a battery of standardized questionnaires. Univariate and multivariate statistical analyses were used to evaluate the parameters of interest. Using attachment theory (J. Bowlby, 1988) and the dynamic stress-vulnerability model of depressive disorder (G. W. Brown & T. O. Harris, 1989) as the analytical frameworks, the authors hypothesized that participants with AJD would: (a) display more insecure attachment styles, (b) be less tolerant of close interpersonal proximity, (c) use more emotion-oriented coping strategies, (d) display lower self-efficacy and self-esteem, and (e) perceive less social support from family, friends, and significant others. We further hypothesized that these variables would be predictive of depressive symptoms. All of the hypotheses were confirmed. The results suggest that the insecure fearful-avoidant attachment style is associated with severe depressive symptoms in patients with AJD. However, other psychosocial factors, such as low self-esteem and poor social support from friends, were more predictive of AJD symptoms. The findings warrant further studies on the risk and protective effects of these factors in the development of AJD and other stress-induced disorders. © 2011 American Orthopsychiatric Association.
Ghandi, Mostafa; Houshmand, Behzad; Nekoofar, Mohammad H.; Tabor, Rachel K.; Yadeghari, Zahra; Dummer, Paul M. H.
2013-01-01
Background: Root surface debridement (RSD) is necessary to create an environment suitable for reattachment of the periodontium. Root surface conditioning may aid the formation of a biocompatible surface suitable for cell reattachment. BioPure™ MTAD (mixture of Doxycycline, citric acid and a detergent) is an endodontic irrigant with antibacterial properties and the ability to remove smear layer. It was hypothesized that MTAD may be useful for root surface conditioning. The efficacy of MTAD as a conditioner was measured by examining fibroblast attachment to root surfaces. Materials and Methods: Thirty-two specimens of human teeth with advanced periodontal disease were used. The surfaces were root planed until smooth. Half of the specimens were treated with 0.9% saline and the other samples with Biopure MTAD. As a negative control group, five further samples were left unscaled with surface calculus. Human gingival fibroblast cells HGF1-PI1 were cultured and poured over the tooth specimens and incubated. After fixation, the samples were sputter-coated with gold and examined with a SEM. The morphology and number of attached, fixed viable cells were examined. The data was analysed using the Mann-Whitney-U statistical test. Results: There was no significant difference between the numbers of attached cells in the experimental group treated with MTAD and the control group treated with saline. Little or no attached cells were seen in the negative control group. Conclusion: RSD created an environment suitable for cell growth and attachment in a laboratory setting. The use of MTAD did not promote the attachment and growth of cells on the surface of human roots following RSD. PMID:23869124
The effect of texture on the crack growth resistance of alumina
NASA Technical Reports Server (NTRS)
Salem, Jonathan A.; Shannon, John L., Jr.; Bradt, Richard C.
1987-01-01
The crack growth resistance of a textured, extruded alumina body was compared with that of an isotropic, isopressed body of similar grain size, density, and chemistry. R-curve levels reflected the preferred orientation; however, R-curve slopes (dK sub IR/d Delta a) were the same in all instances, implying a similar crack growth resistive mechanism. Three orthogonal orientations of crack growth in the two structures exhibited similar forms of K sub IR versus Delta-a curves, for which a schematic diagram for polycrystalline ceramics is proposed.
Simulation and experiment of thermal fatigue in the CPV die attach
NASA Astrophysics Data System (ADS)
Bosco, Nick; Silverman, Timothy; Kurtz, Sarah
2012-10-01
FEM simulation and accelerated thermal cycling have been performed for the CPV die attach. Trends in fatigue damage accumulation and equivalent test time are explored and found to be most sensitive to temperature ramp rate. Die attach crack growth is measured through cycling and found to be in excellent agreement with simulations of the inelastic strain energy accumulated. Simulations of an entire year of weather data provides for the relative ranking of fatigue damage between four cities as well as their equivalent accelerated test time.
Design, fabrication and spin testing of ceramic blade metal disk attachment
NASA Technical Reports Server (NTRS)
Calvert, G.
1979-01-01
A ceramic turbine blade-metal disk attachment was designed for small, non man-rated turbine engine applications. The selected design consisted of a hot pressed silicon nitride blade having a skewed dovetail attachment with a compliant interlayer between the disk and the blade. Two-dimensional and three-dimensional analyses predicted that life goals could be achieved, considering both NDE limitations and crack growth rates for the ceramic material. Twenty ceramic blades were fabricated to closely-held manufacturing tolerances. New fracture mechanics data at elevated temperature are presented.
Osborn, Lawrence A; Stein, Catherine H
2016-10-01
The research examined the role of mental health care providers' perceptions of their professional relationships with consumers in understanding their reports of agency recovery-oriented services and their own sense of job satisfaction and personal growth. Multidisciplinary community mental health care providers (N = 105) responded to an online self-report questionnaire. Providers' reports of higher levels of working alliance and greater provider directiveness in working with consumers was significantly related to providers' reports of higher levels of agency recovery-orientation and higher levels of personal growth. Providers' reports of working alliance accounted for the largest proportion of variance in providers' reports of job satisfaction. Mental health providers' perceptions of relationships with consumers are central to understanding providers' views of agency recovery-orientation and sense of professional and personal well-being.
Quantitative analysis of microtubule orientation in interdigitated leaf pavement cells
Akita, Kae; Higaki, Takumi; Kutsuna, Natsumaro; Hasezawa, Seiichiro
2015-01-01
Leaf pavement cells are shaped like a jigsaw puzzle in most dicotyledon species. Molecular genetic studies have identified several genes required for pavement cells morphogenesis and proposed that microtubules play crucial roles in the interdigitation of pavement cells. In this study, we performed quantitative analysis of cortical microtubule orientation in leaf pavement cells in Arabidopsis thaliana. We captured confocal images of cortical microtubules in cotyledon leaf epidermis expressing GFP-tubulinβ and quantitatively evaluated the microtubule orientations relative to the pavement cell growth axis using original image processing techniques. Our results showed that microtubules kept parallel orientations to the growth axis during pavement cell growth. In addition, we showed that immersion treatment of seed cotyledons in solutions containing tubulin polymerization and depolymerization inhibitors decreased pavement cell complexity. Treatment with oryzalin and colchicine inhibited the symmetric division of guard mother cells. PMID:26039484
Suicidal ideation among Italian and Spanish young adults: the role of sexual orientation.
Baiocco, Roberto; Ioverno, Salvatore; Lonigro, Antonia; Baumgartner, Emma; Laghi, Fiorenzo
2015-01-01
The purpose of the current study was to identify demographic, social, and psychological variables associated with suicidal ideation in an Italian sample and a Spanish sample, taking into account the relevance of sexual orientation as a risk factor for suicide. Three hundred twenty gay and bisexual men, 396 heterosexual men, 281 lesbians and bisexual women, and 835 heterosexual women were recruited. In chi-square and multivariable logistic regression analyses we identified several consistent cross-national risk factors for suicidal ideation: having lower education, not being religious, being homosexual or bisexual, not being engaged in a stable relationship, having lower level of peer and parental attachment, and having depressive symptoms. Interestingly, the strongest risk factor in both samples, after depression symptoms, was sexual orientation.
Growth kinetics of white graphene (h-BN) on a planarised Ni foil surface
Cho, Hyunjin; Park, Sungchan; Won, Dong-Il; Kang, Sang Ook; Pyo, Seong-Soo; Kim, Dong-Ik; Kim, Soo Min; Kim, Hwan Chul; Kim, Myung Jong
2015-01-01
The morphology of the surface and the grain orientation of metal catalysts have been considered to be two important factors for the growth of white graphene (h-BN) by chemical vapour deposition (CVD). We report a correlation between the growth rate of h-BN and the orientation of the nickel grains. The surface of the nickel (Ni) foil was first polished by electrochemical polishing (ECP) and subsequently annealed in hydrogen at atmospheric pressure to suppress the effect of the surface morphology. Atmospheric annealing with hydrogen reduced the nucleation sites of h-BN, which induced a large crystal size mainly grown from the grain boundary with few other nucleation sites in the Ni foil. A higher growth rate was observed from the Ni grains that had the {110} or {100} orientation due to their higher surface energy. PMID:26156068
Effect of Attachment Styles to Parents on Sexual Dysfunction Domains of Married Women
Nia, Anvar Sadat Nayebi; Salari, Parvin; Sharifi, Nasibeh; Nooghani, Hadi Jabbari
2017-01-01
Introduction According to Bowbly attachment theory, attachment of a baby and its main care provider, influences on social growth and the baby’s feelings throughout its life. The present study was performed aim to determine the effect of attachment style to parents on domains of sexual dysfunction in married women. Methods This cross-sectional study was carried out on two hundred married women who were fertile, and referred private and governmental gynecology clinics in Mashhad, Iran, in 2014. Data collection tools were three questionnaires; Demographic and marital questionnaire, Female sexual function index questionnaire, and Adult attachment style questionnaire. Data were analyzed by SPSS version 20 (IBM© SPSS© Statistics version 20 using independent-samples t-test and logistic regression. The statistical tests were performed at the 95% confidence interval. Result Mean of safe attachment style to parents in all aspect of sexual dysfunction was significantly lower (p≤0.01), however, mean of distant attachment style to parents in all aspects of sexual dysfunction was significantly higher (p≤0.05). Conclusion Secure and distance attachment style to the mother showed maximum power of prediction for sexual dysfunction, which indicates the importance of attachment to parents and its impact on adult relationships. PMID:28243413
In Situ Graphene Growth Dynamics on Polycrystalline Catalyst Foils
2016-01-01
The dynamics of graphene growth on polycrystalline Pt foils during chemical vapor deposition (CVD) are investigated using in situ scanning electron microscopy and complementary structural characterization of the catalyst with electron backscatter diffraction. A general growth model is outlined that considers precursor dissociation, mass transport, and attachment to the edge of a growing domain. We thereby analyze graphene growth dynamics at different length scales and reveal that the rate-limiting step varies throughout the process and across different regions of the catalyst surface, including different facets of an individual graphene domain. The facets that define the domain shapes lie normal to slow growth directions, which are determined by the interfacial mobility when attachment to domain edges is rate-limiting, as well as anisotropy in surface diffusion as diffusion becomes rate-limiting. Our observations and analysis thus reveal that the structure of CVD graphene films is intimately linked to that of the underlying polycrystalline catalyst, with both interfacial mobility and diffusional anisotropy depending on the presence of step edges and grain boundaries. The growth model developed serves as a general framework for understanding and optimizing the growth of 2D materials on polycrystalline catalysts. PMID:27576749
NASA Astrophysics Data System (ADS)
Hayasaka, Takeshi; Yoshida, Shinya; Tanaka, Shuji
2017-07-01
This paper reports on the development of a novel buffer layer structure, (100)SrRuO3/(100)LaNiO3/(111)Pt/(111)CeO2, for the epitaxial growth of a (100)/(001)-oriented Pb(Zr,Ti)O3 (PZT)-based thin film on a (111)Si wafer. (111)Pt and (111)CeO2 were epitaxially grown on (111)Si straightforwardly. Then, the crystal orientation was forcibly changed from (111) to (100) at the LaNiO3 layer owing to its strong (100)-self-orientation property, which enabled the cube-on-cube epitaxial growth of the subsequent (100)SrRuO3 layer and preferentially (100)/(001)-oriented PZT-based thin film. The PZT-based epitaxial thin films were comprehensively characterized in terms of the crystallinity, in-plane epitaxial relationships, piezoelectricity, and so forth. This buffer layer structure for the epitaxial growth of PZT can be applied to piezoelectric micro-electro-mechanical systems (MEMS) vibrating ring gyroscopes.
NASA Astrophysics Data System (ADS)
Dicken, Matthew J.; Diest, Kenneth; Park, Young-Bae; Atwater, Harry A.
2007-03-01
We have investigated the growth of barium titanate thin films on bulk crystalline and amorphous substrates utilizing biaxially oriented template layers. Ion beam-assisted deposition was used to grow thin, biaxially textured, magnesium oxide template layers on amorphous and silicon substrates. Growth of highly oriented barium titanate films on these template layers was achieved by molecular beam epitaxy using a layer-by-layer growth process. Barium titanate thin films were grown in molecular oxygen and in the presence of oxygen radicals produced by a 300 W radio frequency plasma. We used X-ray and in situ reflection high-energy electron diffraction (RHEED) to analyze the structural properties and show the predominantly c-oriented grains in the films. Variable angle spectroscopic ellipsometry was used to analyze and compare the optical properties of the thin films grown with and without oxygen plasma. We have shown that optical quality barium titanate thin films, which show bulk crystal-like properties, can be grown on any substrate through the use of biaxially oriented magnesium oxide template layers.
Fracture line morphology of complex proximal humeral fractures.
Hasan, Afsana P; Phadnis, Joideep; Jaarsma, Ruurd L; Bain, Gregory I
2017-10-01
The aim of this study was to assess proximal humeral fracture patterns using 3-dimensional computed tomography images and relate them to the normal osseous landmarks and soft-tissue attachments. Forty-eight 3-dimensional computed tomography scans of proximal humeral fractures were retrospectively collected, and the fractures were transcribed onto proximal humeral templates. We analyzed the common location and orientation of the fracture lines, with a focus on fractures of the articular surface, tuberosities, metaphysis, and proximal diaphysis. These fractures were compared with the attachments of the rotator cuff and glenohumeral capsule. Fifty-two percent of the fractures involved the articular surface. No fractures passed through the bicipital groove, and fractures were more commonly found on the posterior lesser tuberosity and on the anterior greater tuberosity, coinciding with the intervals between the rotator cuff tendon insertions. Intracapsular fractures of the calcar were more common (68%) than extracapsular fractures (32%). On the anterolateral aspect of the proximal humerus, fractures radiated from the articular margin, vertically down through the tuberosity zone between the rotator cuff footprints, meeting horizontally oriented fractures in the metaphyseal zone. On the posterior aspect, vertical fractures from the tuberosity zone continued downward to the metaphyseal zone adjacent to the infraspinatus and teres minor footprints. Fractures of the proximal humerus follow characteristic patterns. Fractures frequently split the greater tuberosity and are closely related to the intervals of the rotator cuff attachments. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.
Castaways: addressing hostility and helplessness in severely lonely adults.
Loboprabhu, Sheila; Molinari, Victor; Asghar-Ali, Ali Abbas
2015-03-01
Hostility and helplessness are recurrent themes in severely lonely adults, and they can be both causes and effects of subjective feelings of loneliness. Since many lonely patients report a history of abuse, hostile and helpless states of mind may reflect identification with hostile (aggressor) or helpless (passive) attachment figures. Hostile intrusiveness and helpless withdrawal by the parent are 2 distinct patterns of parent-child misattunement that can lead to infant disorganization via disrupted emotional communication and to loneliness later in life. Anxious-ambivalent lonely older adults tend to exhibit hyperactivating hostile behaviors (to deal with a core sense of powerlessness), whereas those with fearful-avoidant attachment styles exhibit deactivating helpless behaviors (to deflect intense underlying feelings of rage). Based on this model, we outline different treatment approaches for lonely persons with different attachment styles by describing the successful treatment of two severely lonely, suicidal veterans. We describe an approach to treating hostile and helpless behaviors in lonely patients, using validation, mentalization, reality orientation, and socialization. Validation provides a sense of safety and rapport. Mentalization allows the lonely individual to better appreciate his or her own mental processes and those of others. Reality orientation provides feedback to lonely individuals on whether their perceptions are accurate and reality-based and helps them appreciate the consequences their behavior may have for self and others. Finally, socialization reduces disenfranchisement by teaching/re-teaching individuals social skills that may have become impaired by prolonged isolation.
Isothermal dendritic growth: A low gravity experiment
NASA Technical Reports Server (NTRS)
Glicksman, M. E.; Hahn, R. C.; Lograsso, T. A.; Rubinstein, E. R.; Selleck, M. E.; Winsa, E.
1988-01-01
The Isothermal Dendritic Growth Experiment is an active crystal growth experiment designed to test dendritic growth theory at low undercoolings where convection prohibits such studies at 1 g. The experiment will be essentially autonomous, though limited in-flight interaction through a computer interface is planned. One of the key components of the apparatus will be a crystal growth chamber capable of achieving oriented single crystal dendritic growth. Recent work indicates that seeding the chamber with a crystal of the proper orientation will not, in and of itself, be sufficient to meet this requirement. Additional flight hardware and software required for the STS flight experiment are currently being developed at NASA Lewis Research Center and at Rensselaer Polytechnic Institute.
Falås, P; Longrée, P; la Cour Jansen, J; Siegrist, H; Hollender, J; Joss, A
2013-09-01
Removal of organic micropollutants in a hybrid biofilm-activated sludge process was investigated through batch experiments, modeling, and full-scale measurements. Batch experiments with carriers and activated sludge from the same full-scale reactor were performed to assess the micropollutant removal rates of the carrier biofilm under oxic conditions and the sludge under oxic and anoxic conditions. Clear differences in the micropollutant removal kinetics of the attached and suspended growth were demonstrated, often with considerably higher removal rates for the biofilm compared to the sludge. For several micropollutants, the removal rates were also affected by the redox conditions, i.e. oxic and anoxic. Removal rates obtained from the batch experiments were used to model the micropollutant removal in the full-scale process. The results from the model and plant measurements showed that the removal efficiency of the process can be predicted with acceptable accuracy (± 25%) for most of the modeled micropollutants. Furthermore, the model estimations indicate that the attached growth in hybrid biofilm-activated sludge processes can contribute significantly to the removal of individual compounds, such as diclofenac. Copyright © 2013 Elsevier Ltd. All rights reserved.
NASA Technical Reports Server (NTRS)
2001-01-01
Atomic force microscopy uses laser technology to reveal a defect, a double-screw dislocation, on the surface of this crystal of canavalin, a major source of dietary protein for humans and domestic animals. When a crystal grows, attachment kinetics and transport kinetics are competing for control of the molecules. As a molecule gets close to the crystal surface, it has to attach properly for the crystal to be usable. NASA has funded investigators to look at those attachment kinetics from a theoretical standpoint and an experimental standpoint. Dr. Alex McPherson of the University of California, Irvine, is one of those investigators. He uses X-ray diffraction and atomic force microscopy in his laboratory to answer some of the many questions about how protein crystals grow. Atomic force microscopy provides a means of looking at how individual molecules are added to the surface of growing protein crystals. This helps McPherson understand the kinetics of protein crystal growth. McPherson asks, How fast do crystals grow? What are the forces involved? Investigators funded by NASA have clearly shown that such factors as the level of supersaturation and the rate of growth all affect the habit [characteristic arrangement of facets] of the crystal and the defects that occur in the crystal.
Influence of Natural Organic Matter on Attachment Kinetics of Salmonella Typhimurium
NASA Astrophysics Data System (ADS)
Chowdhury, I.; Zorlu, O.; Hill, J. E.; Walker, S. L.
2011-12-01
Salmonella enterica serovar Typhimurium is one of the most common and virulent bacterial pathogens, usually found in food and water. This waterborne pathogen has been attributed to causing gastroenteritis and typhoid fever, leading to 16 million cases and over half a million deaths worldwide each year. Natural organic matter (NOM) is ubiquitous in environment and previous work has shown NOM to enhance the stability and transport of bacteria cells; hence NOM will certainly interact with Salmonella and affect its transport in environment. The objective of this study was to investigate the influence of NOM (Suwannee River humic acid standard II, SRHA) on the attachment kinetics of a model Salmonella (Salmonella enterica serovar Typhimurium SA5983) to glass. The transport study was conducted in a parallel plate flow chamber using fluorescent microscope to visualize the bacterial cells, which were tagged with green fluorescent protein (GFP). The solution pH was unadjusted, and the flow rate through parallel plate channel was 0.1 mL/min to simulate groundwater conditions. Parameters varied in this study were NOM presence, ion valence (K+, Ca2+) as well as cell growth phase (mid-exponential and late-exponential growth phases). These parameters were chosen because ion valence may alter the NOM conformation and capacity for bridging, as well growth phase impacts the cellular surface chemistry. Extensive characterization of the bacterial cells was conducted including measurements of electrophoretic mobility, hydrophobicity, acidity, surface charge density and extracellular polymeric substance content. Additionally, electrokintic characterization was conducted for the glass. Preliminary results demonstrated the sensitivity of cell attachment to ionic valence and cell growth phase. Also the addition of NOM reduced the attachment of the Salmonella cells significantly under all of these conditions. Without NOM, attachment efficiencies (α) in KCl were similar at both growth phases; however, in the presence of the divalent ion, α decreased as the cells aged. In presence of NOM and KCl, α was significantly lower at late exponential phase than mid exponential phase; whereas, the opposite was observed with divalent ions. These trends indicate the complex role of NOM, which is coupled with ion valence and growth phase, in the transport of Salmonella. Detailed results will be presented along with proposed mechanisms involved in the interactions between Salmonella and NOM. These mechanisms highlight the role this important naturally occurring macromolecule plays in the fate of Salmonella. This understanding will improve our ability to predict the behavior of this pathogen in environmentally relevant conditions.
Nijhout, H Frederik; Cinderella, Margaret; Grunert, Laura W
2014-03-01
The wings of butterflies and moths develop from imaginal disks whose structure is always congruent with the final adult wing. It is therefore possible to map every point on the imaginal disk to a location on the adult wing throughout ontogeny. We studied the growth patterns of the wings of two distantly related species with very different adult wing shapes, Junonia coenia and Manduca sexta. The shape of the wing disks change throughout their growth phase in a species-specific pattern. We measured mitotic densities and mitotic orientation in successive stages of wing development approximately one cell division apart. Cell proliferation was spatially patterned, and the density of mitoses was highly correlated with local growth. Unlike other systems in which the direction of mitoses has been viewed as the primary determinant of directional growth, we found that in these two species the direction of growth was only weakly correlated with the orientation of mitoses. Directional growth appears to be imposed by a constantly changing spatial pattern of cell division coupled with a weak bias in the orientation of cell division. Because growth and cell division in imaginal disk require ecdysone and insulin signaling, the changing spatial pattern of cell division may due to a changing pattern of expression of receptors or downstream elements in the signaling pathways for one or both of these hormones. Evolution of wing shape comes about by changes in the progression of spatial patterns of cell division. © 2014 Wiley Periodicals, Inc.
Bastir, Markus; García Martínez, Daniel; Rios, Luis; Higuero, Antonio; Barash, Alon; Martelli, Sandra; García Tabernero, Antonio; Estalrrich, Almudena; Huguet, Rosa; de la Rasilla, Marco; Rosas, Antonio
2017-07-01
Well preserved thoracic vertebrae of Neandertals are rare. However, such fossils are important as their three-dimensional (3D) spatial configuration can contribute to the understanding of the size and shape of the thoracic spine and the entire thorax. This is because the vertebral body and transverse processes provide the articulation and attachment sites for the ribs. Dorsal orientation of the transverse processes relative to the vertebral body also rotates the attached ribs in a way that could affect thorax width. Previous research indicates possible evidence for greater dorsal orientation of the transverse processes and small vertebral body heights in Neandertals, but their 3D vertebral structure has not yet been addressed. Here we present 15 new vertebral remains from the El Sidrón Neandertals (Asturias, Northern Spain) and used 3D geometric morphometrics to address the above issues by comparing two particularly well preserved El Sidrón remains (SD-1619, SD-1641) with thoracic vertebrae from other Neandertals and a sample of anatomically modern humans. Centroid sizes of El Sidrón vertebrae are within the human range. Neandertals have larger T1 and probably also T2. The El Sidrón vertebrae are similar in 3D shape to those of other Neandertals, which differ from Homo sapiens particularly in central-lower regions (T6-T10) of the thoracic spine. Differences include more dorsally and cranially oriented transverse processes, less caudally oriented spinous processes, and vertebral bodies that are anteroposteriorly and craniocaudally short. The results fit with current reconstructions of Neandertal thorax morphology. Copyright © 2017 Elsevier Ltd. All rights reserved.
Neutron reflectivity measurement of protein A-antibody complex at the solid-liquid interface.
Mazzer, Alice R; Clifton, Luke A; Perevozchikova, Tatiana; Butler, Paul D; Roberts, Christopher J; Bracewell, Daniel G
2017-05-26
Chromatography is a ubiquitous unit operation in the purification of biopharmaceuticals yet few studies have addressed the biophysical characterisation of proteins at the solution-resin interface. Chromatography and other adsorption and desorption processes have been shown to induce protein aggregation which is undesirable in biopharmaceutical products. In order to advance understanding of how adsorption processes might impact protein stability, neutron reflectivity was used to characterise the structure of adsorbed immunoglobulin G (IgG) on model surfaces. In the first model system, IgG was adsorbed directly to silica and demonstrated a side-on orientation with high surface contact. A maximum dimension of 60Å in the surface normal direction and high density surface coverage were observed under pH 4.1 conditions. In chromatography buffers, pH was found to influence IgG packing density and orientation at the solid-liquid interface. In the second model system, which was designed to mimic an affinity chromatography surface, protein A was attached to a silica surface to produce a configuration representative of a porous glass chromatography resin. Interfacial structure was probed during sequential stages from ligand attachment, through to IgG binding and elution. Adsorbed IgG structures extended up to 250Å away from the surface and showed dependence on surface blocking strategies. The data was suggestive of two IgG molecules bound to protein A with a somewhat skewed orientation and close proximity to the silica surface. The findings provide insight into the orientation of adsorbed antibody structures under conditions encountered during chromatographic separations. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.
Gagné-Thivierge, Cynthia; Barbeau, Jean; Levesque, Roger C; Charette, Steve J
2018-06-25
Pseudomonas aeruginosa is an opportunistic pathogen associated with nosocomial infections and disease complications. In the lungs of cystic fibrosis (CF) individuals, biofilm growth plays a crucial role in the persistence and antibiotic resistance of P. aeruginosa. Some strains, adapted to the CF lung microenvironment, show distinguishable phenotypes linked to biofilm production when compared to other strains. Using a novel image analysis quantification approach with crystal violet-stained biofilms, we compared the biofilm formation of four different P. aeruginosa isolates in 24-well plates: PAO1, the reference strain, LESB58 from CF patients' lungs, and PPF-1 and Urg-7, two environmental isolates from dental unit waterlines. We also observed the formation of biofilm-like structures (BLSs) floating in the medium and investigated growth inhibition of the attached biofilm and BLS with Mg2+ or Zn2+. Urg-7 produced the most attached biofilms, but not the most BLSs. Attached biofilms had different responses to cations than BLSs did, but the effect of the cations was similar for all strains. These results demonstrate some diversity of biofilm formation in P. aeruginosa and indicate that chemical inhibition of attached biofilm formation for a specific strain or isolate cannot be predicative of a result on other P. aeruginosa strains or on BLSs.
NASA Technical Reports Server (NTRS)
Noever, David A.
1990-01-01
With and without bioconvective pattern formation, a theoretical model predicts growth in light-limited cultures of motile algae. At the critical density for pattern formation, the resulting doubly exponential population curves show an inflection. Such growth corresponds quantitatively to experiments in mechanically unstirred cultures. This attaches survival value to synchronized pattern formation.
Is Vocabulary Growth Influenced by the Relations among Words in a Language Learner's Vocabulary?
ERIC Educational Resources Information Center
Sailor, Kevin M.
2013-01-01
Several recent studies have explored the applicability of the preferential attachment principle to account for vocabulary growth. According to this principle, network growth can be described by a process in which existing nodes recruit new nodes with a probability that is an increasing function of their connectivity within the existing network.…
Growth and stability of Langmuir-Blodgett films on OH-, H-, or Br-terminated Si(001)
NASA Astrophysics Data System (ADS)
Bal, J. K.; Kundu, S.; Hazra, S.
2010-01-01
Growth of Langmuir-Blodgett (LB) films of nickel arachidate (NiA) on differently terminated (OH-, H-, or Br-terminated) Si(001) substrates and their structural evolution with time have been investigated by x-ray reflectivity technique and complemented by atomic force microscopy. Stable and strongly attached asymmetric monolayer (AML) of NiA is found to grow on freshly prepared oxide-covered Si substrate while unstable and weakly attached symmetric monolayer (SML) of NiA grows on H-terminated Si substrate, corresponding to stable hydrophilic and unstable hydrophobic natures of the substrates, respectively. The structure of LB film on Br-terminated Si substrate, however, shows intermediate behavior, namely, both AML and SML are present on the substrate, indicative of coexisting (hydrophilic and hydrophobic) nature of this terminated surface. Such coexisting nature of the substrate shows unusual growth behavior of LB films: (i) hydrophilic and hydrophobic attachments of NiA molecules in single up stroke of deposition and (ii) growth of few ring-shaped large-heights islands in subsequent deposition. These probably occur due to the presence of substrate-induced perturbation in the Langmuir monolayer and release of initially accumulated strain in the film structures near hydrophilic/hydrophobic interface, respectively, and provide the possibility to grow desired structures (AML or SML) of LB films by passivation-selective surface engineering.
Molecular Beam Epitaxial Growth of GaAs on (631) Oriented Substrates
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cruz Hernandez, Esteban; Rojas Ramirez, Juan-Salvador; Contreras Hernandez, Rocio
2007-02-09
In this work, we report the study of the homoepitaxial growth of GaAs on (631) oriented substrates by molecular beam epitaxy (MBE). We observed the spontaneous formation of a high density of large scale features on the surface. The hilly like features are elongated towards the [-5, 9, 3] direction. We show the dependence of these structures with the growth conditions and we present the possibility of to create quantum wires structures on this surface.
On the interplay between Si(110) epilayer atomic roughness and subsequent 3C-SiC growth direction
NASA Astrophysics Data System (ADS)
Khazaka, Rami; Michaud, Jean-François; Vennéguès, Philippe; Nguyen, Luan; Alquier, Daniel; Portail, Marc
2016-11-01
In this contribution, we performed the growth of a 3C-SiC/Si/3C-SiC layer stack on a Si(001) substrate by means of chemical vapor deposition. We show that, by tuning the growth conditions, the 3C-SiC epilayer can be grown along either the [111] direction or the [110] direction. The key parameter for the growth of the desired 3C-SiC orientation on the Si(110)/3C-SiC(001)/Si(001) heterostructure is highlighted and is linked to the Si epilayer surface morphology. The epitaxial relation between the layers has been identified using X-ray diffraction and transmission electron microscopy (TEM). We showed that, regardless of the top 3C-SiC epilayer orientation, domains rotated by 90° around the growth direction are present in the epilayer. Furthermore, the difference between the two 3C-SiC orientations was investigated by means of high magnification TEM. The results indicate that the faceted Si(110) epilayer surface morphology results in a (110)-oriented 3C-SiC epilayer, whereas a flat hetero-interface has been observed between 3C-SiC(111) and Si(110). The control of the top 3C-SiC growth direction can be advantageous for the development of new micro-electro-mechanical systems.
NASA Technical Reports Server (NTRS)
Green, A. K.
1973-01-01
The influence of substrate imperfections on the nucleation and growth of fcc metals on alkali halides is discussed. Films deposited on well characterized substrated under well defined vacuum evaporation conditions are investigated. The experimental results of this work are correlated with similar work by other investigators. Models which have been proposed by various authors to explain experimental results are critically examined and areas of difficulty are pointed out. The influence of defects on nucleation rate and the orientation of the film is emphasized. Specific examples of impurity effects, irradiation effects and the influence of amorphous layers are discussed in detail. Evidence is shown that the formation of multiply twinned particles is a result of coalescence and growth. The only consistent model for the orienting influence of impurities is shown to be a chemical reaction effect. It is demonstrated that an alkali metal impurity is very likely responsible for the orienting influence of both water vapor exposure and irradiation. A negative result is found for the reported possibility of an orienting influence being transmitted through an amorphous layer.
Preferential orientation of NV defects in CVD diamond films grown on (113)-oriented substrates
NASA Astrophysics Data System (ADS)
Lesik, M.; Plays, T.; Tallaire, A.; Achard, J.; Brinza, O.; William, L.; Chipaux, M.; Toraille, L.; Debuisschert, T.; Gicquel, A.; Roch, J. F.; Jacques, V.
2015-06-01
Thick CVD diamond layers were successfully grown on (113)-oriented substrates. They exhibited smooth surface morphologies and a crystalline quality comparable to (100) electronic grade material, and much better than (111)-grown layers. High growth rates (15-50 {\\mu}m/h) were obtained while nitrogen doping could be achieved in a fairly wide range without seriously imparting crystalline quality. Electron spin resonance measurements were carried out to determine NV centers orientation and concluded that one specific orientation has an occurrence probability of 73 % when (100)-grown layers show an equal distribution in the 4 possible directions. A spin coherence time of around 270 {\\mu}s was measured which is equivalent to that reported for material with similar isotopic purity. Although a higher degree of preferential orientation was achieved with (111)-grown layers (almost 100 %), the ease of growth and post-processing of the (113) orientation make it a potentially useful material for magnetometry or other quantum mechanical applications.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Okumura, Hironori, E-mail: okumura@engineering.ucsb.edu; McSkimming, Brian M.; Speck, James S.
2014-01-06
N-face GaN was grown on free-standing GaN (0001{sup ¯}) substrates at a growth rate of 1.5 μm/h using plasma-assisted molecular beam epitaxy. Difference in growth rate between (0001{sup ¯}) and (0001) oriented GaN depends on nitrogen plasma power, and the (0001{sup ¯}) oriented GaN had only 70% of the growth rate of the (0001) oriented GaN at 300 W. Unintentional impurity concentrations of silicon, carbon, and oxygen were 2 × 10{sup 15}, 2 × 10{sup 16}, and 7 × 10{sup 16} cm{sup −3}, respectively. A growth diagram was constructed that shows the dependence of the growth modes on the difference in the Ga and active nitrogen flux, Φ{sub Ga} − Φ{submore » N*}, and the growth temperature. At high Φ{sub Ga} − Φ{sub N*} (Φ{sub Ga} ≫ Φ{sub N*}), two-dimensional (step-flow and layer-by-layer) growth modes were realized. High growth temperature (780 °C) expanded the growth window of the two-dimensional growth modes, achieving a surface with rms roughness of 0.48 nm without Ga droplets.« less
Lee, Jung-Seok; Kim, Hyun-Suk; Park, So-Yon; Kim, Tae-Wan; Jung, Jae-Suk; Lee, Jong-Bin; Kim, Chang-Sung
2015-01-01
This study aimed to enhance the attachment of periodontal ligament stem cells (PDLSCs) onto the decellularized dental root surface using surface coating with fibronectin and/or calcium phosphate (CaP) and to evaluate the activity of PDLSCs attached to a coated dental root surface following tooth replantation. PDLSCs were isolated from five dogs, and the other dental roots were used as a scaffold for carrying PDLSCs and then assigned to one of four groups according to whether their surface was coated with CaP, fibronectin, CaP/fibronectin, or left uncoated (control). Fibronectin increased the adhesion of PDLSCs onto dental root surfaces compared to both the control and CaP-coated groups, and simultaneous surface coating with CaP and fibronectin significantly accelerated and increased PDLSC adhesion compared to the fibronectin-only group. On in vivo tooth replantation, functionally oriented periodontal new attachment was observed on the CaP/fibronectin-coated dental roots to which autologous PDLSCs had adhered, while in the control condition, dental root replantation was associated only with root resorption and ankylosis along the entire root length. CaP and fibronectin synergistically enhanced the attachment of PDLSCs onto dental root surfaces, and autologous PDLSCs could produce de novo periodontal new attachment in an experimental in vivo model.
2013-01-01
MnSi~1.7 nanowires (NWs) with a single orientation and a large aspect ratio have been formed on a Si(110) surface with the molecular beam epitaxy method by a delicate control of growth parameters, such as temperature, deposition rate, and deposition time. Scanning tunneling microscopy (STM) was employed to study the influence of these parameters on the growth of NWs. The supply of free Si atoms per unit time during the silicide reaction plays a critical role in the growth kinetics of the NWs. High growth temperature and low deposition rate are favorable for the formation of NWs with a large aspect ratio. The orientation relationship between the NWs and the reconstruction rows of the Si(110) surface suggests that the NWs grow along the 11¯0 direction of the silicon substrate. High-resolution STM and backscattered electron scanning electron microscopy images indicate that the NWs are composed of MnSi~1.7. PMID:23339353
NASA Technical Reports Server (NTRS)
Granger, C. L.; Cyr, R. J.
2001-01-01
Arabidopsis thaliana plants were transformed with GFP-MBD (J. Marc et al., Plant Cell 10: 1927-1939, 1998) under the control of a constitutive (35S) or copper-inducible promoter. GFP-specific fluorescence distributions, levels, and persistence were determined and found to vary with age, tissue type, transgenic line, and individual plant. With the exception of an increased frequency of abnormal roots of 35S GFP-MBD plants grown on kanamycin-containing media, expression of GFP-MBD does not appear to affect plant phenotype. The number of leaves, branches, bolts, and siliques as well as overall height, leaf size, and seed set are similar between wild-type and transgenic plants as is the rate of root growth. Thus, we conclude that the transgenic plants can serve as a living model system in which the dynamic behavior of microtubules can be visualized. Confocal microscopy was used to simultaneously monitor growth and microtubule behavior within individual cells as they passed through the elongation zone of the Arabidopsis root. Generally, microtubules reoriented from transverse to oblique or longitudinal orientations as growth declined. Microtubule reorientation initiated at the ends of the cell did not necessarily occur simultaneously in adjacent neighboring cells and did not involve complete disintegration and repolymerization of microtubule arrays. Although growth rates correlated with microtubule reorientation, the two processes were not tightly coupled in terms of their temporal relationships, suggesting that other factor(s) may be involved in regulating both events. Additionally, microtubule orientation was more defined in cells whose growth was accelerating and less stringent in cells whose growth was decelerating, indicating that microtubule-orienting factor(s) may be sensitive to growth acceleration, rather than growth per se.
ERIC Educational Resources Information Center
Doumen, Sarah; Smits, Ilse; Luyckx, Koen; Duriez, Bart; Vanhalst, Janne; Verschueren, Karine; Goossens, Luc
2012-01-01
Identity formation and the perceived quality of one's peer relationships are theorized to be intimately linked in emerging adulthood. The present study examined the associations between identity styles (i.e., information-oriented, normative, and diffuse-avoidant styles) and the quality of relationships with peers (as indexed by friendship quality…
ERIC Educational Resources Information Center
Bylund, Emanuel; Athanasopoulos, Panos
2015-01-01
The encoding of goal-oriented motion events varies across different languages. Speakers of languages without grammatical aspect (e.g., Swedish) tend to mention motion endpoints when describing events (e.g., "two nuns walk to a house") and attach importance to event endpoints when matching scenes from memory. Speakers of aspect languages…
ERIC Educational Resources Information Center
Tharinger, Deborah J.
2008-01-01
In this commentary, the author summarizes the research findings of the four articles from this special issue of "School Psychology Review," titled "Sexual Orientation, Homophobia, Bullying, and Psychological Sequelae in Adolescents: Research and Practice Findings," as well as suggestions for intervention offered by the authors of the articles. She…
ERIC Educational Resources Information Center
Onur, Arzu; Sahin, Elvan; Tekkaya, Ceren
2012-01-01
Environmental attitudes depend on the relative importance that individuals attach to themselves, other people, or all living things. These distinct bases have been found to predict environmental concern, and may act as statistically significant determinants of pro-environmental behaviours. We claim that examining the complex nature of value…
Managing Teacher Preparation for Curriculum Execution and School Improvement in Rivers State
ERIC Educational Resources Information Center
Agi, Ugochukwu Kysburn; Harrison, Anthony
2016-01-01
The teacher remains a critical part of the epicenter of the educational system. The importance attached to the role of the teacher in curriculum execution and value orientation makes teacher preparation or his future duties and responsibilities no less critical. In this paper therefore, teacher preparation is conceived and defined as an academic…
From Crib to Kindergarten: A Continuum of Needs of the Visually Impaired Preschooler.
ERIC Educational Resources Information Center
Harrell, Lois
The paper focuses on the needs of visually impaired preschoolers in various developmental areas. The importance of attachment to a significant other for establishing trust is outlined and the fact that body awareness, object permanence, range of motion, spatial awareness and orientation must be logically and actively introduced is cited. Aspects…
ERIC Educational Resources Information Center
Applis, Stefan
2016-01-01
The educational standards in geography in the German-speaking world separately refer to the areas of competence of judgment and evaluation and thus attach outstanding importance to reflective value orientation in geography classes. The tasks and challenges that arise from that for geography teachers will be investigated in a…
Liu, B; Harrell, R; Lamb, D J; Dresden, M H; Spira, M
1989-10-15
Human fibroblasts and A431 human epidermoid carcinoma cells were cultured on gamma-irradiated human amnion collagen as well as on plastic dishes and non-irradiated collagen coated dishes. The morphology, attachment, growth and short-term cytotoxicity of these culture conditions have been determined. Both irradiated and non-irradiated amnion collagen enhanced the attachment and proliferation of fibroblasts as compared to the plastic dishes. No differences in these properties were observed for A431 cells cultured on irradiated collagen when compared with culture on non-irradiated collagen substrates. Cytotoxicity assays showed that irradiated and non-irradiated collagens were not cytotoxic for either fibroblasts or A431 cells. The results demonstrated that amnion collagen irradiated at doses of 0.25-2.0 Mrads is optimal for cell growth.
NASA Astrophysics Data System (ADS)
Ma, Fei; Su, Jing; Hao, Yongxing; Yao, Bing; Yan, Guanghui
2018-02-01
The problem of uncovering the internal operating function of network models is intriguing, demanded and attractive in researches of complex networks. Notice that, in the past two decades, a great number of artificial models are built to try to answer the above mentioned task. Based on the different growth ways, these previous models can be divided into two categories, one type, possessing the preferential attachment, follows a power-law P(k) ∼k-γ, 2 < γ < 3. The other has exponential-scaling feature, P(k) ∼α-k. However, there are no models containing above two kinds of growth ways to be presented, even the study of interconnection between these two growth manners in the same model is lacking. Hence, in this paper, we construct a class of planar and self-similar graphs motivated from a new attachment way, vertex-edge-growth network-operation, more precisely, the couple of both them. We report that this model is sparse, small world and hierarchical. And then, not only is scale-free feature in our model, but also lies the degree parameter γ(≈ 3 . 242) out the typical range. Note that, we suggest that the coexistence of multiple vertex growth ways will have a prominent effect on the power-law parameter γ, and the preferential attachment plays a dominate role on the development of networks over time. At the end of this paper, we obtain an exact analytical expression for the total number of spanning trees of models and also capture spanning trees entropy which we have compared with those of their corresponding component elements.
Structure and strain relaxation mechanisms of ultrathin epitaxial Pr2O3 films on Si(111)
NASA Astrophysics Data System (ADS)
Schroeder, T.; Lee, T.-L.; Libralesso, L.; Joumard, I.; Zegenhagen, J.; Zaumseil, P.; Wenger, C.; Lupina, G.; Lippert, G.; Dabrowski, J.; Müssig, H.-J.
2005-04-01
The structure of ultrathin epitaxial Pr2O3 films on Si(111) was studied by synchrotron radiation-grazing incidence x-ray diffraction. The oxide film grows as hexagonal Pr2O3 phase with its (0001) plane attached to the Si(111) substrate. The hexagonal (0001) Pr2O3 plane matches the in-plane symmetry of the hexagonal Si(111) surface unit cell by aligning the ⟨101¯0⟩Pr2O3 along the ⟨112¯⟩ Si directions. The small lattice mismatch of 0.5% results in the growth of pseudomorphic oxide films of high crystalline quality with an average domain size of about 50 nm. The critical thickness tc for pseudomorphic growth amounts to 3.0±0.5nm. The relaxation of the oxide film from pseudomorphism to bulk behavior beyond tc causes the introduction of misfit dislocations, the formation of an in-plane small angle mosaicity structure, and the occurence of a phase transition towards a (111) oriented cubic Pr2O3 film structure. The observed phase transition highlights the influence of the epitaxial interface energy on the stability of Pr2O3 phases on Si(111). A mechanism is proposed which transforms the hexagonal (0001) into the cubic (111) Pr2O3 epilayer structure by rearranging the oxygen network but leaving the Pr sublattice almost unmodified.
Neuroscience of human social interactions and adult attachment style
Vrtička, Pascal; Vuilleumier, Patrik
2012-01-01
Since its first description four decades ago, attachment theory (AT) has become one of the principal developmental psychological frameworks for describing the role of individual differences in the establishment and maintenance of social bonds between people. Yet, still little is known about the neurobiological underpinnings of attachment orientations and their well-established impact on a range of social and affective behaviors. In the present review, we summarize data from recent studies using cognitive and imaging approaches to characterize attachment styles and their effect on emotion and social cognition. We propose a functional neuroanatomical framework to integrate the key brain mechanisms involved in the perception and regulation of social emotional information, and their modulation by individual differences in terms of secure versus insecure (more specifically avoidant, anxious, or resolved versus unresolved) attachment traits. This framework describes how each individual's attachment style (built through interactions between personal relationship history and predispositions) may influence the encoding of approach versus aversion tendencies (safety versus threat) in social encounters, implicating the activation of a network of subcortical (amygdala, hippocampus, striatum) and cortical (insula, cingulate) limbic areas. These basic and automatic affective evaluation mechanisms are in turn modulated by more elaborate and voluntary cognitive control processes, subserving mental state attribution and emotion regulation capacities, implicating a distinct network in medial prefrontal cortex (mPFC), superior temporal sulcus (STS), and temporo-parietal junction (TPJ), among others. Recent neuroimaging data suggest that affective evaluation is decreased in avoidantly but increased in anxiously attached individuals. In turn, although data on cognitive control is still scarce, it points toward a possible enhancement of mental state representations associated with attachment insecurity and particularly anxiety. Emotion regulation strategies such as reappraisal or suppression of social emotions are also differentially modulated by attachment style. This research does not only help better understand the neural underpinnings of human social behavior, but also provides important insights on psychopathological conditions where attachment dysregulation is likely to play an important (causal) role. PMID:22822396
Methods for the Organogenesis of Skeletal Muscle in Tissue Culture
NASA Technical Reports Server (NTRS)
Vandenburgh, Herman; Shansky, Janet; DelTatto, Michael; Chromiak, Joseph
1997-01-01
Skeletal muscle structure is regulated by many factors, including nutrition, hormones, electrical activity, and tension. The muscle cells are subjected to both passive and active mechanical forces at all stages of development and these forces play important but poorly understood roles in regulating muscle organogenesis and growth. For example, during embryogenesis, the rapidly growing skeleton places large passive mechanical forces on the attached muscle tissue. These forces not only help to organize the proliferating mononucleated myoblasts into the oriented, multinucleated myofibers of a functional muscle but also tightly couple the growth rate of muscle to that of bone. Postnatally, the actively contracting, innervated muscle fibers are subjected to different patterns of active and passive tensions which regulate longitudinal and cross sectional myofiber growth. These mechanically-induced organogenic processes have been difficult to study under normal tissue culture conditions, resulting in the development of numerous methods and specialized equipment to simulate the in vivo mechanical environment.These techniques have led to the "engineering" of bioartificial muscles (organoids) which display many of the characteristics of in vivo muscle including parallel arrays of postmitotic fibers organized into fascicle-like structures with tendon-like ends. They are contractile, express adult isoforms of contractile proteins, perform directed work, and can be maintained in culture for long periods. The in vivo-like characteristics and durability of these muscle organoids make them useful for long term in vitro studies on mechanotransduction mechanisms and on muscle atrophy induced by decreased tension. In this report, we described a simple method for generating muscle organoids from either primary embrionic avain or neonatal rodent myoblasts.
Vallot, Antoine; Leontiou, Ioanna; Cladière, Damien; El Yakoubi, Warif; Bolte, Susanne; Buffin, Eulalie; Wassmann, Katja
2018-01-08
Cell division with partitioning of the genetic material should take place only when paired chromosomes named bivalents (meiosis I) or sister chromatids (mitosis and meiosis II) are correctly attached to the bipolar spindle in a tension-generating manner. For this to happen, the spindle assembly checkpoint (SAC) checks whether unattached kinetochores are present, in which case anaphase onset is delayed to permit further establishment of attachments. Additionally, microtubules are stabilized when they are attached and under tension. In mitosis, attachments not under tension activate the so-named error correction pathway depending on Aurora B kinase substrate phosphorylation. This leads to microtubule detachments, which in turn activates the SAC [1-3]. Meiotic divisions in mammalian oocytes are highly error prone, with severe consequences for fertility and health of the offspring [4, 5]. Correct attachment of chromosomes in meiosis I leads to the generation of stretched bivalents, but-unlike mitosis-not to tension between sister kinetochores, which co-orient. Here, we set out to address whether reduction of tension applied by the spindle on bioriented bivalents activates error correction and, as a consequence, the SAC. Treatment of oocytes in late prometaphase I with Eg5 kinesin inhibitor affects spindle tension, but not attachments, as we show here using an optimized protocol for confocal imaging. After Eg5 inhibition, bivalents are correctly aligned but less stretched, and as a result, Aurora-B/C-dependent error correction with microtubule detachment takes place. This loss of attachments leads to SAC activation. Crucially, SAC activation itself does not require Aurora B/C kinase activity in oocytes. Copyright © 2017 Elsevier Ltd. All rights reserved.
Growth of <111>-oriented Cu layer on thin TaWN films
NASA Astrophysics Data System (ADS)
Takeyama, Mayumi B.; Sato, Masaru
2017-07-01
In this study, we examine the growth of a <111>-oriented Cu layer on a thin TaWN ternary alloy barrier for good electromigration reliability. The strongly preferentially oriented Cu(111) layer is observed on a thin TaWN barrier even in the as-deposited Cu (100 nm)/TaWN (5 nm)/Si system. Also, this system tolerates annealing at 700 °C for 1 h without silicide reaction. It is revealed that the TaWN film is one of the excellent barriers with thermal stability and low resistivity. Simultaneously, the TaWN film is a candidate for a superior underlying material to achieve the Cu(111) preferential orientation.
NASA Astrophysics Data System (ADS)
Endo, Tamio; Horie, Munehiro; Hirate, Naoki; Itoh, Katsutoshi; Yamada, Satoshi; Tada, Masaki; Itoh, Ken-ichi; Sugiyama, Morihiro; Sano, Shinji; Watabe, Kinji
1998-07-01
Thin films of a-oriented YBa2Cu3Ox (YBCO), Ca-doped c-oriented Bi2(Sr,Ca)2CuOx and nondoped c-oriented Bi2Sr2CuOx (Bi2201) were prepared at low temperatures by ion beam sputtering with supply of oxygen molecules or plasma. The plasma enhances crystal growth of the a-YBCO and Ca-doped Bi2201 phases. This can be interpreted in terms of their higher surface energies. The growth and quality of nondoped Bi2201 are improved with the supply of oxygen molecules. This particular result could be interpreted by the collision process between the oxygen molecules and the sputtered particles.
Vine, N G; Leukes, W D; Kaiser, H; Daya, S; Baxter, J; Hecht, T
2004-06-01
Probiotics for aquaculture are generally only selected by their ability to produce antimicrobial metabolites; however, attachment to intestinal mucus is important in order to remain within the gut of its host. Five candidate probiotics (AP1-AP5), isolated from the clownfish, Amphiprion percula (Lacepéde), were examined for their ability to attach to fish intestinal mucus and compete with two pathogens, Aeromonas hydrophila and Vibrio alginolyticus. Two different radioactive isotopes were used to quantify competition between pathogens and probionts. Attachment of the pathogens was enhanced by the presence of the candidate probiotics. However, the addition of the candidate probiotics after the pathogens resulted in reduced pathogen attachment. Only AP5 caused lower attachment success of V. alginolyticus when added before the pathogen. When AP5 was added first, the average attachment change was 41% compared with 72% when added after V. alginolyticus, suggesting that the probiotic is displaced but that enhanced attachment of the pathogen does not occur. Conversely, when V. alginolyticus was added first, followed by AP5, attachment change was 37% while AP5 had 92% attachment change when added second. This implies that the pathogen was displaced by the candidate probiotic and therefore it appeared that, based on the ability of probiont AP5 to attach to mucus, the growth of the pathogen in the digestive tract might be suppressed by the candidate probiont's presence.
NASA Astrophysics Data System (ADS)
Zhu, X. A.; Tsai, C. T.
2000-09-01
Dislocations in gallium arsenide (GaAs) crystals are generated by excessive thermal stresses induced during the crystal growth process. The presence of dislocations has adverse effects on the performance and reliability of the GaAs-based devices. It is well known that dislocation density can be significantly reduced by doping impurity atoms into a GaAs crystal during its growth process. A viscoplastic constitutive equation that couples the microscopic dislocation density with the macroscopic plastic deformation is employed in a crystallographic finite element model for calculating the dislocation density generated in the GaAs crystal during its growth process. The dislocation density is considered as an internal state variable and the drag stress caused by doping impurity is included in this constitutive equation. A GaAs crystal grown by the vertical Bridgman process is adopted as an example to study the influences of doping impurity and growth orientation on dislocation generation. The calculated results show that doping impurity can significantly reduce the dislocation density generated in the crystal. The level of reduction is also influenced by the growth orientation during the crystal growth process.
Gibbs–Thomson Effect in Planar Nanowires: Orientation and Doping Modulated Growth
Shen, Youde; Chen, Renjie; Yu, Xuechao; ...
2016-06-02
Epitaxy-enabled bottom-up synthesis of self-assembled planar nanowires via the vapor–liquid–solid mechanism is an emerging and promising approach toward large-scale direct integration of nanowire-based devices without postgrowth alignment. In this paper, by examining large assemblies of indium tin oxide nanowires on yttria-stabilized zirconia substrate, we demonstrate for the first time that the growth dynamics of planar nanowires follows a modified version of the Gibbs–Thomson mechanism, which has been known for the past decades to govern the correlations between thermodynamic supersaturation, growth speed, and nanowire morphology. Furthermore, the substrate orientation strongly influences the growth characteristics of epitaxial planar nanowires as opposed tomore » impact at only the initial nucleation stage in the growth of vertical nanowires. The rich nanowire morphology can be described by a surface-energy-dependent growth model within the Gibbs–Thomson framework, which is further modulated by the tin doping concentration. Our experiments also reveal that the cutoff nanowire diameter depends on the substrate orientation and decreases with increasing tin doping concentration. Finally, these results enable a deeper understanding and control over the growth of planar nanowires, and the insights will help advance the fabrication of self-assembled nanowire devices.« less
Gibbs-Thomson Effect in Planar Nanowires: Orientation and Doping Modulated Growth.
Shen, Youde; Chen, Renjie; Yu, Xuechao; Wang, Qijie; Jungjohann, Katherine L; Dayeh, Shadi A; Wu, Tom
2016-07-13
Epitaxy-enabled bottom-up synthesis of self-assembled planar nanowires via the vapor-liquid-solid mechanism is an emerging and promising approach toward large-scale direct integration of nanowire-based devices without postgrowth alignment. Here, by examining large assemblies of indium tin oxide nanowires on yttria-stabilized zirconia substrate, we demonstrate for the first time that the growth dynamics of planar nanowires follows a modified version of the Gibbs-Thomson mechanism, which has been known for the past decades to govern the correlations between thermodynamic supersaturation, growth speed, and nanowire morphology. Furthermore, the substrate orientation strongly influences the growth characteristics of epitaxial planar nanowires as opposed to impact at only the initial nucleation stage in the growth of vertical nanowires. The rich nanowire morphology can be described by a surface-energy-dependent growth model within the Gibbs-Thomson framework, which is further modulated by the tin doping concentration. Our experiments also reveal that the cutoff nanowire diameter depends on the substrate orientation and decreases with increasing tin doping concentration. These results enable a deeper understanding and control over the growth of planar nanowires, and the insights will help advance the fabrication of self-assembled nanowire devices.
Orientations of dendritic growth during solidification
NASA Astrophysics Data System (ADS)
Lee, Dong Nyung
2017-03-01
Dendrites are crystalline forms which grow far from the limit of stability of the plane front and adopt an orientation which is as close as possible to the heat flux direction. Dendritic growth orientations for cubic metals, bct Sn, and hcp Zn, can be controlled by thermal conductivity, Young's modulus, and surface energy. The control factors have been elaborated. Since the dendrite is a single crystal, its properties such as thermal conductivity that influences the heat flux direction, the minimum Young's modulus direction that influences the strain energy minimization, and the minimum surface energy plane that influences the crystal/liquid interface energy minimization have been proved to control the dendritic growth direction. The dendritic growth directions of cubic metals are determined by the minimum Young's modulus direction and/or axis direction of symmetry of the minimum crystal surface energy plane. The dendritic growth direction of bct Sn is determined by its maximum thermal conductivity direction and the minimum surface energy plane normal direction. The primary dendritic growth direction of hcp Zn is determined by its maximum thermal conductivity direction and the minimum surface energy plane normal direction and the secondary dendrite arm direction of hcp Zn is normal to the primary dendritic growth direction.
Formation of nanotwin networks during high-temperature crystallization of amorphous germanium
Sandoval, Luis; Reina, Celia; Marian, Jaime
2015-11-26
Germanium is an extremely important material used for numerous functional applications in many fields of nanotechnology. In this paper, we study the crystallization of amorphous Ge using atomistic simulations of critical nano-metric nuclei at high temperatures. We find that crystallization occurs by the recurrent transfer of atoms via a diffusive process from the amorphous phase into suitably-oriented crystalline layers. We accompany our simulations with a comprehensive thermodynamic and kinetic analysis of the growth process, which explains the energy balance and the interfacial growth velocities governing grain growth. For the <111> crystallographic orientation, we find a degenerate atomic rearrangement process, withmore » two zero-energy modes corresponding to a perfect crystalline structure and the formation of a Σ3 twin boundary. Continued growth in this direction results in the development a twin network, in contrast with all other growth orientations, where the crystal grows defect-free. This particular mechanism of crystallization from amorphous phases is also observed during solid-phase epitaxial growth of <111> semiconductor crystals, where growth is restrained to one dimension. Lastly, we calculate the equivalent X-ray diffraction pattern of the obtained nanotwin networks, providing grounds for experimental validation.« less
Formation of Nanotwin Networks during High-Temperature Crystallization of Amorphous Germanium
Sandoval, Luis; Reina, Celia; Marian, Jaime
2015-01-01
Germanium is an extremely important material used for numerous functional applications in many fields of nanotechnology. In this paper, we study the crystallization of amorphous Ge using atomistic simulations of critical nano-metric nuclei at high temperatures. We find that crystallization occurs by the recurrent transfer of atoms via a diffusive process from the amorphous phase into suitably-oriented crystalline layers. We accompany our simulations with a comprehensive thermodynamic and kinetic analysis of the growth process, which explains the energy balance and the interfacial growth velocities governing grain growth. For the 〈111〉 crystallographic orientation, we find a degenerate atomic rearrangement process, with two zero-energy modes corresponding to a perfect crystalline structure and the formation of a Σ3 twin boundary. Continued growth in this direction results in the development a twin network, in contrast with all other growth orientations, where the crystal grows defect-free. This particular mechanism of crystallization from amorphous phases is also observed during solid-phase epitaxial growth of 〈111〉 semiconductor crystals, where growth is restrained to one dimension. We calculate the equivalent X-ray diffraction pattern of the obtained nanotwin networks, providing grounds for experimental validation. PMID:26607496
IMU-based online kinematic calibration of robot manipulator.
Du, Guanglong; Zhang, Ping
2013-01-01
Robot calibration is a useful diagnostic method for improving the positioning accuracy in robot production and maintenance. An online robot self-calibration method based on inertial measurement unit (IMU) is presented in this paper. The method requires that the IMU is rigidly attached to the robot manipulator, which makes it possible to obtain the orientation of the manipulator with the orientation of the IMU in real time. This paper proposed an efficient approach which incorporates Factored Quaternion Algorithm (FQA) and Kalman Filter (KF) to estimate the orientation of the IMU. Then, an Extended Kalman Filter (EKF) is used to estimate kinematic parameter errors. Using this proposed orientation estimation method will result in improved reliability and accuracy in determining the orientation of the manipulator. Compared with the existing vision-based self-calibration methods, the great advantage of this method is that it does not need the complex steps, such as camera calibration, images capture, and corner detection, which make the robot calibration procedure more autonomous in a dynamic manufacturing environment. Experimental studies on a GOOGOL GRB3016 robot show that this method has better accuracy, convenience, and effectiveness than vision-based methods.
Laser tracker orientation in confined space using on-board targets
NASA Astrophysics Data System (ADS)
Gao, Yang; Kyle, Stephen; Lin, Jiarui; Yang, Linghui; Ren, Yu; Zhu, Jigui
2016-08-01
This paper presents a novel orientation method for two laser trackers using on-board targets attached to the tracker head and rotating with it. The technique extends an existing method developed for theodolite intersection systems which are now rarely used. This method requires only a very narrow space along the baseline between the instrument heads, in order to establish the orientation relationship. This has potential application in environments where space is restricted. The orientation parameters can be calculated by means of two-face reciprocal measurements to the on-board targets, and measurements to a common point close to the baseline. An accurate model is then applied which can be solved through nonlinear optimization. Experimental comparison has been made with the conventional orientation method, which is based on measurements to common intersection points located off the baseline. This requires more space and the comparison has demonstrated the feasibility of the more compact technique presented here. Physical setup and testing suggest that the method is practical. Uncertainties estimated by simulation indicate good performance in terms of measurement quality.
First principles study of biomineral hydroxyapatite
NASA Astrophysics Data System (ADS)
Slepko, Alexander
2010-03-01
Hydroxyapatite (HA) [Ca10(PO4)6(OH)2] is one of the most abundant materials in mammal bone. It crystallizes within the spaces between the tropocollagen chains and strengthens the bone tissue. The mineral content of human bone increases with age reaching a maximum value from which it starts to decrease leading to diseases such as osteomalacia. Therefore, an emergent application of this study is bone repair and the production of synthetic bone. Despite its importance, little is known about the growth of HA crystallites in bones. Nor is it well understood how the HA attaches to protein chains and interacts with the surrounding aqueous solution. Using density functional theory (DFT) we calculate the theoretical ground state structure, electronic and vibration properties of hexagonal HA. We find several low energy structures and analyze the energy barriers for spontaneous phase transitions. We calculate the phonon density of states and study the surface energetics for different orientations. We identify the surfaces with highest reactivity using the frontier orbital approach and analyze interactions between these surfaces and water molecules/amino acids.
Sharma, Anshul; Mori, Taizo; Mahnen, Cory J; Everson, Heather R; Leslie, Michelle T; Nielsen, Alek D; Lussier, Laurent; Zhu, Chenhui; Malcuit, Christopher; Hegmann, Torsten; McDonough, Jennifer A; Freeman, Ernest J; Korley, LaShanda T J; Clements, Robert J; Hegmann, Elda
2017-02-01
The authors report on series of side-chain smectic liquid crystal elastomer (LCE) cell scaffolds based on star block-copolymers featuring 3-arm, 4-arm, and 6-arm central nodes. A particular focus of these studies is placed on the mechanical properties of these LCEs and their impact on cell response. The introduction of diverse central nodes allows to alter and custom-modify the mechanical properties of LCE scaffolds to values on the same order of magnitude of various tissues of interest. In addition, it is continued to vary the position of the LC pendant group. The central node and the position of cholesterol pendants in the backbone of ε-CL blocks (alpha and gamma series) affect the mechanical properties as well as cell proliferation and particularly cell alignment. Cell directionality tests are presented demonstrating that several LCE scaffolds show cell attachment, proliferation, narrow orientational dispersion of cells, and highly anisotropic cell growth on the as-synthesized LCE materials. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
The effect of enterohemorrhagic E. coli infection on the cell mechanics of host cells.
Chen, Yin-Quan; Su, Pin-Tzu; Chen, Yu-Hsuan; Wei, Ming-Tzo; Huang, Chien-Hsiu; Osterday, Kathryn; del Álamo, Juan C; Syu, Wan-Jr; Chiou, Arthur
2014-01-01
Enterohaemorrhagic E. coli (EHEC) is a type of human pathogenic bacteria. The main virulence characteristics of EHEC include the formation of attaching and effacing lesions (A/E lesions) and the production of one or more Shiga-like toxins, which may induce human uremic complications. When EHEC infects host cells, it releases translocated intimin receptor (Tir) and effector proteins inside the host cells, inducing the rearrangement and accumulation of the F-actin cytoskeleton, a phenotype leading to the formation of pedestals in the apical cell surface, and the growth of stress fibers at the base of the cells. To examine the effect of EHEC infection on cell mechanics, we carried out a series of experiments to examine HeLa cells with and without EHEC infection to quantify the changes in (1) focal adhesion area, visualized by anti-vinculin staining; (2) the distribution and orientation of stress fibers; and (3) the intracellular viscoelasticity, via directional video particle tracking microrheology. Our results indicated that in EHEC-infected HeLa cells, the focal adhesion area increased and the actin stress fibers became thicker and more aligned. The cytoskeletal reorganization induced by EHEC infection mediated a dramatic increase in the cytoplasmic elastic shear modulus of the infected cells, and a transition in the viscoelastic behavior of the cells from viscous-like to elastic-like. These changes in mechanobiological characteristics might modulate the attachments between EHEC and the host cell to withstand exfoliation, and between the host cell and the extracellular matrix, and might also alter epithelial integrity.
Oriented antibody immobilization on self-assembled monolayers applied as impedance biosensors
NASA Astrophysics Data System (ADS)
Tsugimura, Kaiki; Ohnuki, Hitoshi; Wu, Haiyun; Endo, Hideaki; Tsuya, Daiju; Izumi, Mitsuru
2017-11-01
Oriented immobilization of antibodies on a sensor chip is crucial for enhancing both the sensitivity and antigen-binding capacity of immunosensors. Here, we report a comparative study of the effect of oriented and random antibody immobilization on the binding efficiency by electrochemical impedance spectroscopy (EIS). Oriented immobilization of anti-myoglobin immunoglobulin G (anti-Myo IgG) was achieved by bonding to an Fc receptor of protein G (PrG) on a self-assembled monolayer (SAM), which results in the myoglobin (Myo) binding sites being exposed outside the sensing surface. Random immobilization of anti-Myo IgG was achieved by direct covalent attachment to the SAM surface. Both immobilizations were applied to interdigitated electrodes to enhance the electrochemical signal, and the Myo biosensor performance was then evaluated by a series of EIS measurements. We found that (i) the rate of the normalized charge transfer resistance for the oriented sample was 3 times higher than that for the random sample and (ii) the detection limit was 0.001 ng/mL, which is the lowest recorded detection limit among Myo immunosensors based on EIS. These findings indicate that oriented antibody immobilization is crucial for preparing highly sensitive EIS-based biosensors.
Pre-coalescence scaling of graphene island sizes
NASA Astrophysics Data System (ADS)
Das, Shantanu; Drucker, Jeff
2018-05-01
Graphene grown using cold-wall chemical vapor deposition on Cu surfaces follows a classical nucleation and growth mechanism. Following nucleation at the earliest growth stages, isolated crystallites grow, impinge, and coalesce to form a continuous layer. During the pre-coalescence growth regime, the size distributions of graphene crystallites exhibit scaling of the form N(s) = θ/⟨s⟩2 g(s/⟨s⟩), where s is the island area, θ is the graphene coverage, ⟨s⟩ is the average island area, N is the areal density, and g(x) is a scaling function. For graphene grown on Cu surfaces that have been annealed in a reducing Ar + H2 ambient, excellent data collapse onto a universal Avrami scaling function is observed irrespective of graphene coverage, surface roughness, or Cu grain size. This result is interpreted to indicate attachment-limited growth and desorption of diffusing C-containing species. Graphene grown on Cu surfaces that were annealed in a non-reducing environment exhibits a qualitatively different scaling function, indicating diffusion-limited growth with a lower attachment barrier combined with C detachment from the graphene edges.
Distribution of protein and phosphorus in spring growth of rusty blackhaw
Robert M. Blair; E.A. Epps
1967-01-01
Spring growth of rusty blackhaw (Viburnum rufidulum), a moderately preferred deer browse on southern ranges, contained more crude protein and phosphorus in the terminal inch of the twigs and the attached leaves than in segments 2 and 3 inches from the tip.
NASA Technical Reports Server (NTRS)
Tsapatsis, Michael (Inventor); Lai, Zhiping (Inventor)
2008-01-01
In certain aspects, the invention features methods for forming crystalline membranes (e.g., a membrane of a framework material, such as a zeolite) by inducing secondary growth in a layer of oriented seed crystals. The rate of growth of the seed crystals in the plane of the substrate is controlled to be comparable to the rate of growth out of the plane. As a result, a crystalline membrane can form a substantially continuous layer including grains of uniform crystallographic orientation that extend through the depth of the layer.
Gravity response mechanisms of lateral organs and the control of plant architecture in Arabidopsis
NASA Astrophysics Data System (ADS)
Mullen, J.; Hangarter, R.
Most research on gravity responses in plants has focused on primary roots and shoots, which typically grow in a vertical orientation. However, the patterns of lateral organ formation and their growth orientation, which typically are not vertical, govern plant architecture. For example, in Arabidopsis, when lateral roots emerge from the primary root, they grow at a nearly horizontal orientation. As they elongate, the roots slowly curve until they eventually reach a vertical orientation. The regulation of this lateral root orientation is an important component affecting the overall root system architecture. We have found that this change in orientation is not simply due to the onset of gravitropic competence, as non-vertical lateral roots are capable of both positive and negative gravitropism. Thus, the horizontal growth of the new lateral roots is determined by what is called the gravitropic set-point angle (GSA). In Arabidopsis shoots, rosette leaves and inflorescence branches also display GSA-dependent developmental changes in their orientation. The developmental control of the GSA of lateral organs in Arabidopsis provides us with a useful system for investigating the components involved in regulating directionality of tropistic responses. We have identified several Arabidopsis mutants that have either altered lateral root orientations, altered orientation of lateral organs in the shoot, or both, but maintain normal primary organ orientation. The mgsa ({m}odified {g}ravitropic {s}et-point {a}ngle) mutants with both altered lateral root and shoot orientation show that there are common components in the regulation of growth orientation in the different organs. Rosette leaves and lateral roots also have in common a regulation of positioning by red light. Further molecular and physiological analyses of the GSA mutants will provide insight into the basis of GSA regulation and, thus, a better understanding of how gravity controls plant architecture. [This work was supported by the National Aeronautics and Space Administration through grant no. NCC 2-1200.
Trajectories of attachment in older age: interpersonal trauma and its consequences.
Bachem, Rahel; Levin, Yafit; Solomon, Zahava
2018-06-04
Previous studies suggest that attachment insecurities may increase after trauma exposure, an effect documented only at a group level. This study explores the heterogeneity of changes over time and examines the associations of the nature of the traumatic event (interpersonal and nonpersonal), and its consequences (posttraumatic stress disorder [PTSD] and loneliness) with attachment trajectories. Two groups of Israeli veterans participated: 164 former prisoners-of-war and 185 combat veterans. Attachment was assessed at four points (1991-2015). Risk factors were evaluated in 1991. Using latent growth mixture modeling, trajectories of attachment insecurities were explored. Three avoidance trajectories (stability, decrease, inverse u-shaped) and two anxiety trajectories (stability, decrease) were identified. The inverse u-shaped avoidance trajectory was associated with captivity, humiliation, loneliness, and PTSD, and stable avoidance was associated with loneliness. Stable anxiety was associated with captivity and loneliness. Attachment insecurities can change during aging and persist decades after a trauma. Trauma-related risk factors are related to more deleterious trajectories.
Wan, Minxi; Hou, Dongmei; Li, Yuanguang; Fan, Jianhua; Huang, Jianke; Liang, Songtao; Wang, Weiliang; Pan, Ronghua; Wang, Jun; Li, Shulan
2014-07-01
As the optimal source of astaxanthin, Haematococcus pluvialis was cultured for commercial production of astaxanthin through two continuous phases: cell growth and astaxanthin induction. In this study, the efficiency of an attached system for producing astaxanthin from H. pluvialis was investigated and compared to that of the suspended system (bubble column bioreactor) under various conditions. Results showed that this attached system is more suitable for photoinduction of H. pluvialis than the suspended bioreactor. Under the optimal conditions, the astaxanthin productivity of the attached system was 65.8 mg m(-2)d(-1) and 2.4-fold of that in the suspended system. This attached approach also offers other advantages over suspended systems, such as, producing astaxanthin under a wide range of light intensities and temperatures, saving water, ease to harvest cells, resisting contamination. Therefore, the attached approach can be considered an economical, environmentally friendly and highly-efficient technology for producing astaxanthin from H. pluvialis. Copyright © 2014 Elsevier Ltd. All rights reserved.
Heteroepitaxial growth of Pt and Au thin films on MgO single crystals by bias-assisted sputtering
Tolstova, Yulia; Omelchenko, Stefan T.; Shing, Amanda M.; ...
2016-03-17
The crystallographic orientation of a metal affects its surface energy and structure, and has profound implications for surface chemical reactions and interface engineering, which are important in areas ranging from optoelectronic device fabrication to catalysis. However, it can be very difficult and expensive to manufacture, orient, and cut single crystal metals along different crystallographic orientations, especially in the case of precious metals. One approach is to grow thin metal films epitaxially on dielectric substrates. In this work, we report on growth of Pt and Au films on MgO single crystal substrates of (100) and (110) surface orientation for use asmore » epitaxial templates for thin film photovoltaic devices. We develop bias-assisted sputtering for deposition of oriented Pt and Au films with sub-nanometer roughness. We show that biasing the substrate decreases the substrate temperature necessary to achieve epitaxial orientation, with temperature reduction from 600 to 350 °C for Au, and from 750 to 550 °C for Pt, without use of transition metal seed layers. Additionally, this temperature can be further reduced by reducing the growth rate. Biased deposition with varying substrate bias power and working pressure also enables control of the film morphology and surface roughness.« less
Coal storage hopper with vibrating screen agitator
Daw, Charles S.; Lackey, Mack E.; Sy, Ronald L.
1984-01-01
The present invention is directed to a vibrating screen agitator in a coal storage hopper for assuring the uniform feed of coal having sufficient moisture content to effect agglomeration and bridging thereof in the coal hopper from the latter onto a conveyor mechanism. The vibrating screen agitator is provided by a plurality of transversely oriented and vertically spaced apart screens in the storage hopper with a plurality of vertically oriented rods attached to the screens. The rods are vibrated to effect the vibration of the screens and the breaking up of agglomerates in the coal which might impede the uniform flow of the coal from the hopper onto a conveyer.
Coal storage hopper with vibrating-screen agitator
Daw, C.S.; Lackey, M.E.; Sy, R.L.
1982-04-27
The present invention is directed to a vibrating screen agitator in a coal storage hopper for assuring the uniform feed of coal having sufficient moisture content to effect agglomeration and bridging thereof in the coal hopper from the latter onto a conveyer mechanism. The vibrating scrren agitator is provided by a plurality of transversely oriented and vertically spaced apart screens in the storage hopper with a plurality of vertically oriented rods attached to the screens. The rods are vibrated to effect the vibration of the screens and the breaking up of agglomerates in the coal which might impede the uniform flow of the coal from the hopper onto a conveyer.
Genetic analysis of the gravitropic set-point angle in lateral roots of Arabidopsis
NASA Technical Reports Server (NTRS)
Mullen, J. L.; Hangarter, R. P.; Kiss, J. Z. (Principal Investigator)
2003-01-01
Research on gravity responses in plants has mostly focused on primary roots and shoots, which typically orient to a vertical orientation. However, the distribution of lateral organs and their characteristically non-vertical growth orientation are critical for the determination of plant form. For example, in Arabidopsis, when lateral roots emerge from the primary root, they grow at a nearly horizontal orientation. As they elongate, the roots slowly curve until they eventually reach a vertical orientation. The regulation of this lateral root orientation is an important component affecting overall root system architecture. We found that this change in orientation is not simply due to the onset of gravitropic competence, as non-vertical lateral roots are capable of both positive and negative gravitropism. Thus, the horizontal growth of new lateral roots appears to be determined by what is called the gravitropic set-point angle (GSA). This developmental control of the GSA of lateral roots in Arabidopsis provides a useful system for investigating the components involved in regulating gravitropic responses. Using this system, we have identified several Arabidopsis mutants that have altered lateral root orientations but maintain normal primary root orientation. c2003 COSPAR. Published by Elsevier Ltd. All rights reserved.
Chatterjee, Monischa B; Baumann, Nicola; Koole, Sander L
2017-12-01
The dispositional inability to self-regulate one's own emotions intuitively is described as state orientation and has been associated with numerous psychological impairments. The necessity to search for buffering effects against negative outcomes of state orientation is evident. Research suggests that state-oriented individuals can benefit from feeling close to others. Yet, there are individual differences in the extent to which supportive relationships are valued. The objective of the present article was to examine whether high importance of relatedness increases the utilization of its situational activation among state-oriented individuals. In two studies, we examined whether situational activation of relatedness (by priming for similarities with a close other) is particularly advantageous for state-oriented individuals who attach high importance to relatedness (i.e., benevolence values). The sample consisted of 170 psychology undergraduates in Study 1 and 177 in Study 2. In both studies, state-oriented participants high in benevolence had reduced negative mood after thinking about similarities (vs. differences). State-oriented participants low in benevolence did not benefit from priming for similarities. In Study 2, physical presence of a close other did not boost priming effects for state-oriented participants but stimulated action-oriented participants to attune their self-regulatory efforts to the context. The results show that state-oriented individuals who value benevolence do benefit from a situational activation of relatedness. © 2016 Wiley Periodicals, Inc.
Dynamic Scaling and Island Growth Kinetics in Pulsed Laser Deposition of SrTiO 3
Eres, Gyula; Tischler, J. Z.; Rouleau, C. M.; ...
2016-11-11
We use real-time diffuse surface x-ray diffraction to probe the evolution of island size distributions and its effects on surface smoothing in pulsed laser deposition (PLD) of SrTiO 3. In this study, we show that the island size evolution obeys dynamic scaling and two distinct regimes of island growth kinetics. Our data show that PLD film growth can persist without roughening despite thermally driven Ostwald ripening, the main mechanism for surface smoothing, being shut down. The absence of roughening is concomitant with decreasing island density, contradicting the prevailing view that increasing island density is the key to surface smoothing inmore » PLD. We also report a previously unobserved crossover from diffusion-limited to attachment-limited island growth that reveals the influence of nonequilibrium atomic level surface transport processes on the growth modes in PLD. We show by direct measurements that attachment-limited island growth is the dominant process in PLD that creates step flowlike behavior or quasistep flow as PLD “self-organizes” local step flow on a length scale consistent with the substrate temperature and PLD parameters.« less
Dynamic Scaling and Island Growth Kinetics in Pulsed Laser Deposition of SrTiO 3
DOE Office of Scientific and Technical Information (OSTI.GOV)
Eres, Gyula; Tischler, J. Z.; Rouleau, C. M.
We use real-time diffuse surface x-ray diffraction to probe the evolution of island size distributions and its effects on surface smoothing in pulsed laser deposition (PLD) of SrTiO 3. In this study, we show that the island size evolution obeys dynamic scaling and two distinct regimes of island growth kinetics. Our data show that PLD film growth can persist without roughening despite thermally driven Ostwald ripening, the main mechanism for surface smoothing, being shut down. The absence of roughening is concomitant with decreasing island density, contradicting the prevailing view that increasing island density is the key to surface smoothing inmore » PLD. We also report a previously unobserved crossover from diffusion-limited to attachment-limited island growth that reveals the influence of nonequilibrium atomic level surface transport processes on the growth modes in PLD. We show by direct measurements that attachment-limited island growth is the dominant process in PLD that creates step flowlike behavior or quasistep flow as PLD “self-organizes” local step flow on a length scale consistent with the substrate temperature and PLD parameters.« less
Engineering of oriented carbon nanotubes in composite materials
Beigmoradi, Razieh; Mohebbi-Kalhori, Davod
2018-01-01
The orientation and arrangement engineering of carbon nanotubes (CNTs) in composite structures is considered a challenging issue. In this regard, two groups of in situ and ex situ techniques have been developed. In the first, the arrangement is achieved during CNT growth, while in the latter, the CNTs are initially grown in random orientation and the arrangement is then achieved during the device integration process. As the ex situ techniques are free from growth restrictions and more flexible in terms of controlling the alignment and sorting of the CNTs, they are considered by some as the preferred technique for engineering of oriented CNTs. This review focuses on recent progress in the improvement of the orientation and alignment of CNTs in composite materials. Moreover, the advantages and disadvantages of the processes are discussed as well as their future outlook. PMID:29515955
Effects of Nanoparticle Size on Multilayer Formation and Kinetics of Tethered Enzymes.
Lata, James P; Gao, Lizeng; Mukai, Chinatsu; Cohen, Roy; Nelson, Jacquelyn L; Anguish, Lynne; Coonrod, Scott; Travis, Alexander J
2015-09-16
Despite numerous applications, we lack fundamental understanding of how variables such as nanoparticle (NP) size influence the activity of tethered enzymes. Previously, we showed that biomimetic oriented immobilization yielded higher specific activities versus nonoriented adsorption or carboxyl-amine binding. Here, we standardize NP attachment strategy (oriented immobilization via hexahistidine tags) and composition (Ni-NTA coated gold NPs), to test the impact of NP size (⌀5, 10, 20, and 50 nm) on multilayer formation, activity, and kinetic parameters (kcat, KM, kcat/KM) of enzymes representing three different classes: glucose-6-phosphate isomerase (GPI), an isomerase; Glyceraldehyde-3-phosphate dehydrogenase S (GAPDHS), an oxidoreductase; and pyruvate kinase (PK), a transferase. Contrary to other reports, we observed no trend in kinetic parameters for individual enzymes when found in monolayers (<100% enzyme coverage), suggesting an advantage for oriented immobilization versus other attachment strategies. Saturating the NPs to maximize activity per NP resulted in enzyme multilayer formation. Under these conditions, total activity per NP increased with increasing NP size. Conversely, specific activity for all three enzymes was highest when tethered to the smallest NPs, retaining a remarkable 73-94% of the activity of free/untethered enzymes. Multilayer formations caused a clear trend of kcat decreasing with increasing NP size, yet negligible change in KM. Understanding the fundamental relationships between NP size and tethered enzyme activity enables optimized design of various applications, maximizing activity per NP or activity per enzyme molecule.
Gravity and the orientation of cell division
NASA Technical Reports Server (NTRS)
Helmstetter, C. E.
1997-01-01
A novel culture system for mammalian cells was used to investigate division orientations in populations of Chinese hamster ovary cells and the influence of gravity on the positioning of division axes. The cells were tethered to adhesive sites, smaller in diameter than a newborn cell, distributed over a nonadhesive substrate positioned vertically. The cells grew and divided while attached to the sites, and the angles and directions of elongation during anaphase, projected in the vertical plane, were found to be random with respect to gravity. However, consecutive divisions of individual cells were generally along the same axis or at 90 degrees to the previous division, with equal probability. Thus, successive divisions were restricted to orthogonal planes, but the choice of plane appeared to be random, unlike the ordered sequence of cleavage orientations seen during early embryo development.
Anasakti, the Hindu ideal, and its relationship to well-being and orientations to happiness.
Banth, Sudha; Talwar, Charu
2012-09-01
Anasakti, a Sanskrit term for traits like non-attachment, equipoise, selfless duty orientation, and effort in the absence of concern for the outcome, can be regarded as a Hindu-ideal cluster of personality traits. The relationship of Anasakti with well-being and the three distinct happiness orientations was explored through a study of 676 college students and a sample of 65 yogic practitioners in India. The findings revealed that the yogic practitioners were markedly higher in Anasakti than the secular population. For the yogic population, there was a large correlation between Anasakti and the Orientation to Meaningful Life, and it accounted for more than 20% of the variance in the regression of Anasakti against all the measures of well-being. The yogic population's scores also correlated with several other measures of well-being. The scores of the secular population were less strongly related to the well-being scores; though, several correlation coefficients were statistically significant.
Goat serum as an alternative to establish cell culture from Indian major carp, Cirrhinus mrigala.
Nanda, P K; Swain, P; Nayak, S K; Dash, S; Routray, P; Swain, S K; Patra, B C
2009-01-01
Serum from goat, calf, and chicken sources were evaluated in terms of attachment, growth, and proliferation of explants of Indian major carp, Cirrhinus mrigala. The attachment of explants viz. heart, liver, and kidney was directly proportional to the concentration of the serum. Among these sera, the highest percentage of attachment, growth, and proliferation was recorded for 10% goat serum and 15% newborn calf serum without affecting their cell morphology. On contrary to these sera, chicken serum at 15% concentration was found to be mildly toxic for all the explants. The cell count was significantly high for the kidney, liver, and heart at 10% goat serum among all the tested sera as well as concentration. Similarly, the liver, heart, and kidney explants were found to survive up to the tenth, seventh, and ninth passage, respectively. Therefore, the goat serum at 10% concentration can be used as effectively as newborn calf serum for routine culture of fish cells.
A role for PVRL4-driven cell–cell interactions in tumorigenesis
Pavlova, Natalya N; Pallasch, Christian; Elia, Andrew EH; Braun, Christian J; Westbrook, Thomas F; Hemann, Michael; Elledge, Stephen J
2013-01-01
During all stages of tumor progression, cancer cells are subjected to inappropriate extracellular matrix environments and must undergo adaptive changes in order to evade growth constraints associated with the loss of matrix attachment. A gain of function screen for genes that enable proliferation independently of matrix anchorage identified a cell adhesion molecule PVRL4 (poliovirus-receptor-like 4), also known as Nectin-4. PVRL4 promotes anchorage-independence by driving cell-to-cell attachment and matrix-independent integrin β4/SHP-2/c-Src activation. Solid tumors frequently have copy number gains of the PVRL4 locus and some have focal amplifications. We demonstrate that the transformation of breast cancer cells is dependent on PVRL4. Furthermore, growth of orthotopically implanted tumors in vivo is inhibited by blocking PVRL4-driven cell-to-cell attachment with monoclonal antibodies, demonstrating a novel strategy for targeted therapy of cancer. DOI: http://dx.doi.org/10.7554/eLife.00358.001 PMID:23682311
The attachment of α -synuclein to a fiber: A coarse-grain approach
NASA Astrophysics Data System (ADS)
Ilie, Ioana M.; den Otter, Wouter K.; Briels, Wim J.
2017-03-01
We present simulations of the amyloidogenic core of α-synuclein, the protein causing Parkinson's disease, as a short chain of coarse-grain patchy particles. Each particle represents a sequence of about a dozen amino acids. The fluctuating secondary structure of this intrinsically disordered protein is modelled by dynamic variations of the shape and interaction characteristics of the patchy particles, ranging from spherical with weak isotropic attractions for the disordered state to spherocylindrical with strong directional interactions for a β-sheet. Flexible linkers between the particles enable sampling of the tertiary structure. This novel model is applied here to study the growth of an amyloid fibril, by calculating the free energy profile of a protein attaching to the end of a fibril. The simulation results suggest that the attaching protein readily becomes trapped in a mis-folded state, thereby inhibiting further growth of the fibril until the protein has readjusted to conform to the fibril structure, in line with experimental findings and previous simulations on small fragments of other proteins.
Simulation of Nonlinear Instabilities in an Attachment-Line Boundary Layer
NASA Technical Reports Server (NTRS)
Joslin, Ronald D.
1996-01-01
The linear and the nonlinear stability of disturbances that propagate along the attachment line of a three-dimensional boundary layer is considered. The spatially evolving disturbances in the boundary layer are computed by direct numerical simulation (DNS) of the unsteady, incompressible Navier-Stokes equations. Disturbances are introduced either by forcing at the in ow or by applying suction and blowing at the wall. Quasi-parallel linear stability theory and a nonparallel theory yield notably different stability characteristics for disturbances near the critical Reynolds number; the DNS results con rm the latter theory. Previously, a weakly nonlinear theory and computations revealed a high wave-number region of subcritical disturbance growth. More recent computations have failed to achieve this subcritical growth. The present computational results indicate the presence of subcritically growing disturbances; the results support the weakly nonlinear theory. Furthermore, an explanation is provided for the previous theoretical and computational discrepancy. In addition, the present results demonstrate that steady suction can be used to stabilize disturbances that otherwise grow subcritically along the attachment line.
Heinze, Justin E; Cook, Stephanie H; Wood, Erica P; Dumadag, Anne C; Zimmerman, Marc A
2018-01-01
Exposure to violence during adolescence is associated with increased risk behaviors and mental health problems in adulthood. Friendship attachment during adolescence may, however, mitigate the negative effects of exposure to violence on trajectories of depression and anxiety in young adulthood. In this study, we used growth curve modeling to examine associations between exposure to violence and mental health outcomes, followed by multi-group analyses with friendship attachment as the moderator. The sample was drawn from a longitudinal study (12 waves; 1994-2012) of 676 (54% female) urban high school students. We found strong positive associations between exposure to violence during adolescence and later self-reported depressive and anxiety symptoms. Notably, securely attached adolescents reported faster decreases in mental health symptoms as a function of violence relative to their insecurely attached peers as they transitioned into adulthood.